description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of the apparatus;
FIG. 2 is a top plan view taken on line 2--2 in FIG. 1;
FIG. 3 is a sectional elevation taken on line 3--3 in FIG. 2;
FIG. 4 is a sectional elevation taken on line 4--4 in FIG. 2;
FIG. 5 is a cross-section taken on line 5--5 in FIG. 4;
FIG. 6 is a sectional plan taken on line 6--6 in FIG. 5;
FIG. 7 is an exploded perspective view of the magnetic readout head and its mounting;
FIG. 8 is an exploded perspective view of the gear train by which the manually actuable crank or lever drives the card carrier into the apparatus for automatic return by the return spring.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The apparatus comprises a housing or case 10 within which is fixedly mounted a rod 12 forming a guide means along which a card carrier 14 is reciprocated back and forth on a linear path. The carrier 14 includes integral therewith a cylinder 16 coaxially circumjacent and mounted upon the rod 12, which forms a sliding path for the reciprocation of the carrier 14. The rod 12 emerges from the cylinder 16 through respective end walls 18 and 20 which are slidingly sealed to the rod 12 by low-friction gaskets 22.
The carrier 14 has a slot 24 opening laterally of the path of movement of the carrier and adapted to receive a thin record member in the form of a flat card 26. Card 26 has thereon a magnetic strip 28 on which there are a plurality of parallel magnetic coded tracks (in this example two), which are adapted to be read out by a magnetic readout head 30. (FIG. 7)
The carrier 14 is moved from a starting position adjacent one end 32 of its path formed by the rod 12, to the opposite or stop end 34 of the rod. This movement is effected by rotation of a manually operable actuating crank or lever 36 operating through a drive means in the form of a gear train 38 (FIG. 8) which includes a rack 40 on the carrier 14. The carrier 14 is moved to the right (FIGS. 1, 2, 4, 6) by rotating the crank 36 downward through an arc of about 30 degrees as shown in FIG. 1. The crank 36 is secured by a pin 42 (FIG. 8) to a shaft 44 journaled in the housing 10. Slideable on the shaft 44 is a clutch ring 46 keyed to the shaft by a pin 48 passing through a longitudinal diametric slot 50 formed in the shaft 44. In this way rotation is imparted to the ring 46 while longitudinal or axial movement on the shaft 44 is still permitted within the limits of the slot 50. Sloping or oblique cam faces 52 on the clutch ring 46 engage complementary faces 54 on a segment gear 56 freely journaled on the shaft 44 and forming the first gear in the gear train 38.
Another shaft 58 is secured to the housing 10 parallel to the shaft 44. This is done by mounting the shaft 58 in an interior boss 60 and secured by a pin 62. Freely journaled on the shaft 58 is a gear 64 having a brake drum 66 forming a portion of a unidirectional braking means for preventing return of the carrier 14 if the crank 36 is prematurely released. The gear 64 is secured by pins 68 to a larger gear 70 also journaled on the shaft 58, which gear meshes with a pinion 72 freely journaled on the shaft 44 and meshing with the rack 40.
Mounted to the housing 10 beneath the starting end 32 of the guide rod 12 is a spiral, constant force, drive or return spring 74 of the negator type which serves to bias the carrier 14 to the left (FIGS. 4 and 6). The free end of the spring 74 is secured to the carrier 14 at 76 (FIG. 3) and serves to return the carrier 14 to the starting end of the rod 12 after it has been moved to the opposite or stop end 34 and then released, as will be described hereinafter.
The clutch ring 52 is pressed into clutching engagement with its complement, the segment gear 56, by a compression spring 78 circumjacent the shaft 44. The force of spring 78 is normally sufficient to keep the cam faces 52 and 54 in firm engagement and thus transmit the arcuate rotation of the shaft 44 to the gear segment 56 and thence through the gears 64, 70, 72 to the rack 40 and move the carrier 14 to the right from the starting position 32 of its path to the stop position 34. At the end 34 of the rod 12, the end plate 20 of the cylinder abuts the end wall of the housing 10 by striking an interiorly directed boss 80. Continued rotation of the clutch ring 46 beyond this point forces the cam faces 52 and 54 out of engagement by moving the ring 46 axially against the bias of the spring 78.
As soon as the cam faces 52 clear the faces 54, the gear train 38 is effectively freed from the shaft 44, and the carrier 14 is then moved back to the left in FIG. 6 at a constant speed by the constant force negator spring 74.
Although the force exerted by the spring 74 is substantially constant over its working range, the carrier 14 would nonetheless accelerate during this travel excursion. To maintain constant velocity, the aforementioned cylinder 16 is provided, which in addition to serving as the guide means for the carrier 14 on the rod 12, also serves as part of a dash pot means, the complementary part of which is a piston 82 on the rod 12 within the cylinder 16 and having a piston ring 84 therearound.
The operating cycle of the apparatus involves a movement of the cylinder 16 from the left to the right, so that the piston 82 at the start occupies a position in the right end of the cylinder 16 and then at the stop position occupies a position in the left end of the cylinder 16 as seen in FIG. 6. In this stroke of the movement, i.e. when the card 26 is being moved into the machine and preparatory to read out, minimum resistance is desired. Therefore means are provided for allowing ready exit of air from the left-hand side of the piston 82 and ready ingress of air to the right-hand side of the piston 82. While this may be done by valving in the body of the cylinder 16, in this embodiment it is done by a ball check valve 86 in the piston 82 itself which allows unobstructed flow of air to the right in FIG. 6. Thus as the carrier 14 and cylinder 16 move to the right in FIG. 6, minimum resistance is encountered. On the return stroke, driven by the bias spring 74, speed control is essential; and therefore escape of air from the right-hand side of the cylinder 16 is under control of an adjustable bleed orifice 88, the flow resistance of which is controlled by a threaded needle valve 90 (FIG. 3). The action of the piston 82 in the cylinder 16 thus constitutes a unidirectional pneumatic dash pot which stabilizes the return speed of the carrier 14, driven by the biasing spring 74, to a constant value. This is highly important to the proper readout of the magnetic data coded onto the card 26. The coding on the card is so positioned that readout does not start until a short distance after the clutch faces 52/54 have been disengaged and the return stroke has started under the influence of the spring 64. This allows the action of the dash pot to stablize the carrier velocity before readout starts by the magnetic head 30.
Just a small fraction of an inch before the end wall 20 of the cylinder 16 comes against the abutment stop 80 (FIG. 6) to bring about disengagement of the clutch faces 52/54, the right-hand edge 92 of the card 26 (FIG. 4) engages the arm 94 of a microswitch 96 mounted on the interior of the casing. Even momentary closing of the switch 96 effectuates a circuit lock into the readout circuitry connected to the magnetic readout head 30. The return of the card 26 past the head 30 in the return stroke of the carrier 14 brings about a reading of the coded data on the magnetic strip 28, irrespective of whether the crank arm 36 is allowed to return or not. Thereafter, when the crank 36 is released, it is returned to its uppermost position by the action of a return spring 98 tensioned between a short arm 100 on the clutch ring 46 and a stud 101 in the housing 10 projecting inward from the housing 10.
The arcuate limits of oscillation of the crank 36 are determined by an arcuate slot 102 formed in a boss 104 on the housing 10, within which oscillates a pin 106 pressed into and extending from a diametral bore 108 formed in the shaft 44. As seen in FIG. 8 the various parts 78, 46 and 72 on the shaft 44 are held in place by a snap ring 110, which rides in a circumferential groove 112 on the inwardly extending end of the shaft 44. Similarly a snap ring 114 seated in a groove 116 in the inner end of the shaft 58 retains in position the parts journaled on that shaft.
If an inexperienced operator should release the crank 36 before he has moved it through its full excursion to close the switch 96, the drive spring 74 would return the carrier 14 to its starting position and the spring 98 would return the crank 36. Yet there would be no readout, and the inexperienced operator might conclude that there was something wrong with the machine or with the readout circuitry. To preclude this, there is provided the aforementioned unidirectional brake means in the form of a brake plate 118 pivoted on a gudgeon 120 mounted in a pair of mounting brakets 122 extending inwardly from the housing 10. The free end of the plate 118 has a large hole 124 through which extends the shaft 58, and at the extreme end of the plate 118 is a laterally extending arcuate brake shoe 126 which overhangs the brake drum 66.
As shown in FIG. 4, the shoe 126 engages the drum 66 to the left of a line projected through the shafts 120 and 58. A torsion spring 128 mounted circumjacent the gudgeon 120 biases the plate 118 clockwise, thus biasing the shoe 126 into engagement with the drum 66. Rotation of the drum 66 as the crank 36 is moved downward is in a counterclockwise direction, so that the brake engagement is relieved and the gear train can move freely in that direction. However, should the crank 36 be released at any time prior to its full stroke, the clockwise rotation of the drum 66 (FIG. 4) would bring the two parts 66 and 126 into firm frictional engagement, thereby braking any return movement of the carrier 14 under the influence of the return spring 74.
To free the brake shoe 126 from the drum 66 at the stop end of the stroke, the clutch ring 46 is provided with an arm 130 which engages a pin 132 on the plate 118 just a fraction of an inch after the shaft 44 has moved the clutch ring 46 far enough to disengage the cam surfaces 52/54, and before the pin 106 has reached the end of its stroke in the arcuate slot 102. Thus as the operator completes the downward stroke of the crank 36, the arm 130, pressing on the pin 132, rotates the plate 118 counterclockwise sufficiently to relieve the frictional engagement of the shoe 126 against the drum 66. Thus the return spring 74 is free to drive the card 26 past the head 30 and effectuate the desired code readout.
The card 26 is retained firmly in the slot 24 of the carrier 14 by a retaining arm 134 hinged to the frame 10 at pivot 136 and biased counterclockwise (FIG. 4) by a torsion spring 138. A series of leaf springs 143 are lanced downwardly from an elongate plate 142 riveted to the arm 134. The hinge spring 138 biases the arm 134 downward against a bracket 140 extending inwardly from the housing 10 as shown in FIGS. 2 and 5. This places the leaf springs 140 in position to resiliently engage the top edge of the card 26 as it is being carried back and forth by the carrier 14. However, should jamming occur at any time during the use of the machine, the arm 134 may be retracted upward and the exposed upper edge of the card 26 readily grasped to extract the card from the carrier 14. Thus the card is not trapped within the confines of the machine, but is readily accessible at all time, irrespective of the point of operation at which jamming might possibly occur.
The housing 10 is made in two parts as shown in FIGS. 2 and 6 held together by securing bolts 142.
In accordance with the present invention the readout head 30 is mounted so as to accommodate itself to slight irregularities or undulations in the card 26, at the same time being maintained in sufficiently exact registration with the magnetic strip 28 to assure accurate readout of the coded magnetic data. To this end the housing 10 is provided with an inwardly extending bracket 144 (FIG. 7) forming a pivotal support for a mounting arm 146 pivoted to the end of the bracket 144 by a pivot pin 148. The axis of pivot pin 148 lies thus in a plane parallel to the card 26 and transverse of its path of movement as it is reciprocated by the carrier 14. Adjacent the end of the arm 146 is formed a downwardly projecting head carrier 150, constituting a cradle for the readout head 30. The cradle 150 has a downwardly extending pair of gimbal arms 152 connected by a bottom 154. In the respective arms 152 are formed aligned bores 156, in one of which is mounted a fixed pointed pivot pin 158 and in the other of which is mounted an adjustable pointed pivot pin 160, the adjustment being provided by the threading of the pin 160 in a nut 162 secured to the gimbal arm. The pins 158 and 160 ride in respective sockets 164 in the head 30, and thereby support the head in the cradle 150 for pivotal adjustment about an axis paralleling the path of movement of the card 26.
Precise vertical, i.e. lateral, relationship of the readout head 30 with respect to the magnetic strip 28 on the card 26 is provided by restraining the free end of the arm 146 against vertical movement, while still permitting horizontal movement brought about by pivoting of the arm 146 about the pivot pin 148. This is effected by a short projection 166 extending from the cradle 150 into a horizontal groove 168 formed in the bracket 140. A torsion spring 170 circumjacent the pivot pin 148 bears against the arm 146 and biases the head 30 against the card 26. This beings the convex face 172 of the head 30 into firm readout engagement against the magnetic strip 28 with its coded data thereon. In the example shown, two pickup cores 174 have been shown in the head for picking up a respective pair of parallel signal paths in the magnetic strip 28; but, of course, any number of such parallel paths may be provided.
The head 30 biased by the spring 170 presses the card 26 against an abutment in the form of a roller 176 having an axle 178 journaled in a U-shaped trunnion bearing 180. The ends of axle 178 also serve to mount the trunnion bearing 180 in a bracket 182 extending inwardly from the housing 10 and having elongate mounting bores 184. These bores mount trunnion bearing 180 with limited back-and-forth movement, biased by a compression spring 186 held in place by a boss 188 on trunnion bearing 180. In this way the card 26, as it moves in and out on the carrier 14, is pinched resiliently between the readout head 30 and the abutment roller 176. The curved periphery of roller 176 complements the convex face 172 to provide accurate and precise readout of the magnetic strip 28.
The head 30 is centered resiliently in its mounting on the pivot pins 158/160 by a double arc leaf spring 190 seated in a groove 192 in the bottom portion 154 of the cradle 150. In this way the head is centered in the cradle 150, with slight pivotal adjustment about the axis 158/160 being permitted, thereby allowing the readout cores 174 to accommodate themselves to slight undulations or irregularities in the card 26.
Since the present apparatus is manually powered rather than by electric motor, it is possible to render the pickup circuitry much less vulnerable to spurious signals by confining magnetic materials to those in the head 30. All other parts of the apparatus within magnetic range of the head or the magnetic strip 28 are made of non-magnetic material, such as plastic. The centering spring 190, for example, is preferably made of berillium copper, so as to have no magnetic influence on the pickup function of the head 30. | An apparatus is provided in which a card, such as a credit card, carrying a magnetic strip of one or more tracks of coded data is inserted. Manual operation of an external crank or lever causes the card to be drawn into the apparatus. At the end of the stroke, the carrier in which the card rides is freed from the crank and returns at a constant, spring-driven speed, past a magnetic readout head, the output of which is connected to any suitable decoding circuit. The readout head is gimbaled so that it can ride with constant pressure against the magnetic strip on the card while at the same time adjusting itself to undulations or other slight deformations in the card. There is no significant amount of magnetic material within magnetic range of the readout head, so that danger of spurious signals being injected into the decoding circuit is minimized. | 6 |
This is a division of application Ser. No. 801,138, filed May 27, 1977, now U.S. Pat. No. 4,119,566, which was a division of application Ser. No. 617,601, filed Sept. 29, 1975, now U.S. Pat. No. 4,057,510.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a continuous process for the manufacture of a nitrogenrich gas stream by the partial oxidation of a hydrocarbonaceous feed with air. More specifcally, the present invention pertains to the production of a mixture of inert gases substantially comprising N 2 , A and CO 2 .
2. Description of the Prior Art
Hydrocarbonaceous feedstocks, e.g. petroleum oil, have been reacted previously with a free oxygen-containing gas in the presence of steam to produce gaseous mixtures principally comprising H 2 and CO. For example, see coassigned U.S. Pat. No. 3,097,081--Du Bois Eastman et al. The free oxygen-containing gas is usually substantially pure oxygen, e.g. 95 mole % O 2 or more, in order to reduce the amount of nitrogen in the product gas.
SUMMARY
The subject process relates to the production of a continuous stream of nitrogen-rich gases by the partial oxidation of a hydrocarbonaceous feed with air. A stream of inert gas substantially comprising nitrogen, argon and carbon dioxide may be produced. The product gas contains substantially no gaseous nitrogen oxide compounds, no particulate carbon, and no free oxygen gas. In the process, a hydrocarbonaceous feedstock containing substantially no metals nor noncombustible materials is reacted with air by partial oxidation. The atomic ratio of free oxygen in said air to carbon in said hydrocarbonaceous fuel is in the range of about 1.7 to stoichiometric, or preferably 0.2 less than stoichiometric. The weight ratio of air to hydrocarbonaceous fuel may be in the range of about 7 to 22. The reaction takes place in a free-flow, unpacked, refractory-lined gas generator, free from catalyst, at a temperature in the range of about 1300° to 3000° F. and a pressure in the range of about 1 to 250 atmospheres. Optionally, by further processing, including drying and conventional gas purification techniques, various mixtures of inert gases comprising nitrogen, carbon dioxide and argon may be obtained.
DESCRIPTION OF THE INVENTION
In the subject continuous process a hydrocarbonaceous feed is reacted by partial oxidation with air under conditions producing a nitrogen-rich gas stream containing up to about 80 to 90 mole % (dry basis) of elemental nitrogen gas, and higher. Since the atmosphere in the reaction zone is slightly reducing, the nitrogen-rich gas produced contains substantially no oxides of nitrogen, i.e. less than 10 parts per million (ppm) of the oxides of nitrogen (NO x where x is a number in the range 1/2 to 21/2). Further, there is substantially no free oxygen nor particulate carbon in the effluent gas from the generator.
The nitrogen-rich product gas may be used to blanket or pressurize vessels containing materials that become hazardous or corrosive in the presence of air, or it may be used to pressurize an oil well for secondary recovery of oil. Since the inert gas produced will contain substantially no NO x , the gas is noncorrosive to the steel casings used in oil wells or to steel vessels. Further, if the inert product gas is used for oil well injection, it may be injected hot without condensing the steam. Thus, the volume of gas available for injecting is increased and the oil in the formation may be heated up at the same time.
The generator for carrying out the partial oxidation reaction in the subject process preferably consists of a compact, unpacked, free-flow, noncatalytic, refractorylines steel pressure vessel of the type described in coassigned U.S. Patent 2,809,104 issued to D. M. Strasser et al, which patent is incorporated herewith by reference. The nitrogen-rich effluent gas stream from the gas generator may have the following composition in mole % (wet basis): N 2 53 to 74; CO 2 4 to 13; A 0.65 to 0.95; H 2 nil to 20; CO nil to 15; H 2 O 8 to 19; COS nil to 0.05; H 2 S nil to 0.3; NO x less than 10 ppm; and particulate carbon less than 100 ppm.
Optically, by conventional gas drying and purification techniques, inert gas mixtures of different compositions may be derived from the effluent stream from the gas generator comprising N 2 , A and CO 2 . For example, inert gas compositions (1) and (2) below in mole % may be obtained: (1) N 2 84 to 92, CO 2 7 to 15, and A 0.9 to 1.1; and (2) N 2 98.8 to 98.9, and A 1.1 to 1.2.
A wide variety of hydrocarbonaceous fuels containing substantially no metals nor noncombustible materials are suitable as feedstocks for the partial oxidation process, either alone or in combination with each other. The hydrocarbonaceous feed may be gaseous, liquid or solid. The hydrocarbonaceous feeds include fossil fuels such as: various liquid hydrocarbon fuels including petroleum distillates, liquefied petroleum gas, naphtha, kerosine, gasoline, gas oil, fuel oil, coal oil, shale oil, tar sand oil, aromatic hydrocarbons such as benzene, toluene, xylene fractions, coal tar, furfural extract of coker gas oil, and mixtures thereof. Suitable liquid hydrocarbon fuel feeds as used herein are by definition liquid hydrocarbonaceous fuel feeds that have a gravity in degrees API in the range of about -20 to 100.
Included also by definition as a hydrocarbonaceous fuel are liquid oxygenated hydrocarbonaceous materials, i.e. liquid hydrocarbon materials containing combined oxygen, including alcohols, ketones, aldehydes, organic acids, esters, ethers, oxygenated fuel oil and mixtures thereof. Further, a liquid oxygenated hydrocarbonaceous material may be in admixture with one of said liquid petroleum materials.
Included also are pumpable slurries of solid hydrocarbonaceous fuels, e.g. particulate carbon and other ash-free carbon-containing solids in a liquid hydrocarbon fuel and mixtures thereof. By definition, gaseous hydrocarbonaceous fuels include natural gas, methane, ethane, propane, butane, pentane, water gas, coke-oven gas, refinery gas, acetylene tail gas, ethylene off-gass, and mixtures thereof. Both gaseous and liquid fuels may be mixed and used simultaneously and may include paraffinic, olefinic, naphthenic and aromatic compounds.
In conventional partial oxidation procedures, it is normal to produce from ordinary hydrocarbonaceous fuel feeds about 0.2 to 20 weight percent of free carbon soot (on the basis of carbon in the hydrocarbonaceous fuel feed). The free carbon soot is produced in the reaction zone of the gas generator, for example, by cracking hydrocarbonaceous fuel feeds. Carbon soot will prevent damage to the refractory lining in the generator by constituents which are present as ash components in some residual oils. In conventional synthesis gas generation processes with heavy crude or fuel oil feeds, it is preferable to leave about 1 to 3 weight percent of the carbon in the feed as free carbon soot in the product gas. With lighter distillate oils, progressively lower carbon soot yields are maintained. However, since the hydrocarbonaceous fuel feeds in the subject process are specified as being free from metals and ash-free, i.e. no noncombustible solids, carbon soot is not required in the reaction zone to protect the refractory lining and substantially all of the particulate carbon produced may be converted into carbon oxides.
Particulate carbon and the oxides of nitrogen may be eliminated from the subject process gas stream primarily by regulating the oxygen to carbon ratio (O/C, atoms of oxygen in oxidant per atom of carbon in hydrocarbonaceous feed) in the range of about 1.7 to stoichiometric and preferably 0.2 less than stoichiometric, wherein by definition the term "stoichiometric" means the stoichiometric number of atoms of oxygen theoretically required to completely react with each mole of hydrocarbonaceous feedstock to produce carbon dioxide and water.
Thus, the (O/C, atom/atom) ratio may be in the range of about 1.7 to 4.0 and preferably 2.0 to 3.8 for gaseous hydrocarbonaceous fuels; and in the range of about 1.7 to 3.0 and preferably 2.0 to 2.8 for liquid hydrocarbonaceous fuels. When the O/C atomic ratio reaches stoichiometric, the moles of H 2 and CO in the product gas theoretically drop to zero. The weight ratio of air to hydrocarbonaceous fuel may be in the range of about 7 to 22. In the above relationship, the O/C ratio is to be based upon the total of free oxygen atoms in the oxidant stream plus combined oxygen atoms in the hydrocarbonaceous fuel feed molecules.
In order to operate the subject generator over the entire O/C range, i.e. about 1.7 to 4.0, additional cooling may have to be provided in some cases to keep the reaction temperature from exceeding 3000° F. In the subject process, the nitrogen in the air reactant is sufficient to act as the temperature moderator and will prevent the reaction zone temperature from exceeding 3000° F. when the O/C atomic ratio is 3 and below for a gaseous hydrocarbonaceous fuel, or when the O/C atomic ratio is 2 and below for a liquid hydrocarbonaceous fuel. In such instance, for example, no supplemental H 2 O other than that normally found in the reactant streams need be introduced into the reaction zone as a temperature moderator since the nitrogen in the air is an adequate temperature moderator.
However, when the O/C atomic ratios exceed these specific ranges, then some form of additional cooling may be used. Thus, in the subject process, the reaction temperature may be maintained at a maximum of 3000° F. when the hydrocarbonaceous fuel is in the gaseous phase and the O/C atomic ratio is above 3.0 to 4.0 or when said hydrocarbonaceous fuel is in the liquid phase and the O/C atomic ratio is above 2.0 to 3.0 by recycling a cooled portion of the effluent inert gas stream to the reaction zone. For example, sufficient effluent gas from the reaction zone may be cooled to a temperature in the range of about 80 to 300° F. by external heat exchange and then recycled to the gas generator to maintain the reaction zone at a maximum temperature of 3000° F. Alternatively, cooling of the gas in the reaction zone may be effected by installing water-cooled coils in the gas generator, or by simultaneously introducing a small amount of supplemental H 2 O from an external source into the reaction zone along with said reactants in the amount of about 0.05 to 1.0 and preferably less than 0.15 parts by weight of H 2 O per part by weight of fuel.
The hot effluent gas stream from the reaction zone of the synthesis gas generator may be cooled to a temperature in the range of about 80° to 900° F. by indirect heat exchange in a waste heat boiler. This nitrogen-rich gas stream may be used as an inert gas mixture or may be dried and purified by conventional procedures to separate any or all of the unwanted constituents.
Thus, by conventional means substantially all of the H 2 O may be removed from the process gas stream. For example, the clean process gas stream may be cooled to a temperature below the dew point of water by conventional means to condense out and separate H 2 O. Next, the feed stream may be substantially dehydrated by contact with a desiccant such as alumina.
In other embodiments, by conventional gas purification methods including, for example, cryogenic cooling and solvent absorption, H 2 , CO and acid gas (CO 2 , H 2 S and COS) may be removed; or alternately, only the sulfur-containing gases (if present) and not the CO 2 may be separated from the effluent gas from the gas generator. For example, the dry process gas stream may be cooled to a temperature near the triple point in the range of about -70° to -50° F. to condense out and separate a liquid stream comprising from about 0 to 70 volume percent of the CO 2 , H 2 S and COS originally present (depending upon the pressure and the amount present in the raw gas). Further purification of the process gas stream may be effected by any suitable conventional system employing physical absorption with a liquid solvent, e.g. cold methanol, N-methyl-pyrrolidone. A simplified system in which removal of the remaining H 2 S, COS, CO 2 and H 2 O may be accomplished by physical absorption in cold methanol will be described below.
In a conventional liquid-gas absorption column, e.g. tray-type, at a temperature in the range of about -20° to -70° F. and a pressure in the range of about 25 to 150 atmospheres, about 10 to 20 standard cubic feed (SCF) of the partially purified process gas stream are contacted by each pound of cold methanol. Preferably, the pressure in the absorption column is the same as the pressure in the gas generator less ordinary drop in the lines and equipment. The solvent rate is inversely proportional to the pressure and to the solubility. Solubility is a function of temperature and the compositions of the solvent and of the gas mixture. Acid gases are highly soluble in methanol at high pressures and low temperatures. Then, when the pressure is reduced, these gases may be readily stripped from the solvent without the costly steam requirement of conventional chemical-absorption methods.
The difference in solubility between CO 2 and the gaseous sulfur compounds in methanol and in most polar solvents makes it possible to selectively remove H 2 S and COS before CO 2 removal. Further, the H 2 S and COS may be concentrated into a fraction suitable for feeding a conventional Claus unit where elemental sulfur is produced.
The process gas stream leaving the gas purification zone may have the following composition in mole %: N 2 61 to 99; A 0.75 to 1.21; H 2 nil to 23; CO nil to 17; and CH 4 nil to 1.3; CO 2 nil to 2000 ppm; H 2 S nil to 10 ppm; and COS nil to 10 ppm. This gas stream may be used as an inert blanket gas in a carburizing process or reforming furnace.
The liquid solvent absorbent leaving the gas purification zone charged with acid gas may be regenerated by suitable conventional techniques, including flashing, stripping, boiling and combinations thereof, to produce a CO 2 -rich gas stream and a separate stream of sulfur-containing gases. This H 2 S-rich gas stream may be introduced into a conventional Claus unit for the production of byproduct sulfur.
Optically, the process gas stream leaving the acid gas absorption zone may be purified to remove the other noninert inpurities. A CO-rich gas stream and a separate H 2 -rich gas stream substantially comprising 98 to 99 mole % hydrogen may be obtained thereby. Any suitable conventional system employing physical absorption with a liquid solvent may be employed for obtaining the CO-rich gas stream from the effluent gas stream leaving the acid gas absorption column. The CO-rich gas stream comprises 98 mole % CO and 2 mole % CO 2 . For example, the effluent gas stream from the acid gas scrubber may be contacted in a conventional packed or tray-type column with a countercurrent stream of cuprous acetate dissolved in aqua-ammonia solution.
In another embodiment, the effluent gas from the generator may be burned in a second stage with a controlled amount of air and optionally with a combustion catalyst to convert all of the H 2 and CO into H 2 O and CO 2 without producing soot, NO x or free oxygen in the process gas stream. The H 2 O and optionally CO 2 , H 2 S and COS may be then removed from the process gas stream in the gas purification zone in the manner previously described.
The following example is offered as a better understanding of the present invention, but the invention is not to be construed as unnecessarily limited thereto.
EXAMPLE I
The process fuel oil in this example has a gravity of 17.7° API, a gross heating value of 18,650 BTU/pound, and the following analysis in weight percent: C 86.5; H 11.2; O 0.0; N 0.5; S 1.8; ash nil; and metals nil. 357 pounds per hour of said process fuel oil at a temperature of about 60° F. are charged into the reaction zone of a free-flow, unpacked, noncatalytic, refractorylined gas generator by way of the annulus passage of a conventional annulus-type burner. Simultaneously, 39,559 standard cubic feet per hour of dry air at a temperature of about 63° F. are passed into the reaction zone by way of the center passage of said burner so as to atomize said fuel oil feed at the tip of the burner. The resulting mixture of oil and air is reacted at an autogenous temperature of about 2700° F. and at a pressure of 21 atomspheres.
44,289 standard cubic feet per hour of an inert effluent gas stream are discharged from the reaction zone having the following analysis in mole % (dry basis): N 2 69.8; CO 2 5.8; A 0.9; H 2 7.2; CO 16.2; CH 4 nil; H 2 S 0.2; COS 0.01; and NO x less than 0.5 ppm. This inert gas stream may be used for oil formation flooding or as a blanketing gas when small amounts of CO and H 2 are not objectionable.
Optionally, all of the H 2 , CO, CH 4 , H 2 S, COS and H 2 O may be removed by conventional gas purification techniques to produce an inert gas mixture comprising in mole %: N 2 91.2; CO 2 7.6; and A 1.2. This inert gas stream may be used as a pressurizing gas or as a blanketing gas.
The process of the invention has been described generally and by example with reference to an oil feedstock of particular composition for purposes of clarity and illustration only. It will be apparent to those skilled in the art from the foregoing that various modifications of the process and the materials disclosed herein can be made without departure from the spirit of the invention. | A nitrogen-rich inert gas mixture is produced by the partial oxidation of a hydrocarbonaceous feed containing substantially no metals nor noncombustible materials with air in a free-flow, unpacked, refractory-lined gas generator at a temperature in the range of about 1300° to 3000° F. and a pressure in the range of about 1 to 250 atmospheres. The product gas will comprise a mixture of nitrogen, argon and carbon dioxide and may contain small amounts of hydrogen and carbon monoxide, depending on the O/C atomic ratio selected. The atomic ratio of free oxygen in said air to carbon in said hydrocarbonaceous fuel is in the range of about 1.7 to stoichiometric, or slightly less than stoichiometric. By operating at this level of O/C atomic ratio, the H 2 +CO content of the product gas may be minimized or deleted, substantially all of the particulate carbon may be oxidized, substantially no NO x is produced, and the product gas contains substantially no free oxygen. Further, the sensible heat recovered from the product gas may be used to manufacture by-product high pressure steam for export. The nitrogen-rich product gas may be used for oil formation flooding, or as a pressurizing or blanketing gas. Costly gas compressors may be avoided since the product gas may be produced at or above use pressure. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This Application claims priority from, and benefit of, U.S. Provisional Application 61/985,654 filed on Apr. 29, 2014. The entire contents of this application are hereby incorporated by reference into this Application.
TECHNICAL FIELD
The present invention is generally in the field of immunology and relates to monoclonal antibodies (mAbs) that specifically bind to insecticidal delta-endotoxins known as Cry1Ca, hybridoma cells producing such antibodies, and enzyme-linked immune-sorbent assays (ELISA) for detecting Cry1Ca proteins in a range of samples.
BACKGROUND OF THE INVENTION
Bacillus thuringiensis is a gram positive bacterium that produces a variety of crystalline protein toxins during sporulation generally referred to as delta-endotoxins or Cry proteins. Many of these are highly toxic to a range of agronomic insect pests but are generally harmless to mammals and most other organisms. One such delta-endotoxin, Cry1Ca, is insecticidal to certain lepidopteran pests found in North and South America corn fields.
Cry1Ca has been shown to effectively control fall armyworm, Spodoptera frugiperda , and Cry1Fa resistant fall armyworm when expressed in maize plants as a full length protein (Sheets, J., et al., Entomological Society of America , Annual Meeting, Nov. 12, 2013, Austin Tex.). The full length Cry1Ca holotoxin is cleaved by native enzymes in the insect gut to produce a core toxin having approximately 624 residues of the amino terminus depending on the insect and gut conditions. Cry1Ca core toxin-containing proteins and genes are therefore attractive candidates for developing recombinant crop plants such as corn, soy, cotton, canola, and others often referred to as genetically modified (GM) plants.
Companies which develop and market GM crop seeds containing recombinant DNA that confer beneficial new traits are required to formulate, implement and adhere to strict product stewardship plans. These stewardship plans require the use of validated quantitative and qualitative protein detection methods for the recombinant protein to track trait introgression and seed production activities, as well as to monitor the GM trait during and after harvest. These detection methods must be facile and robust enough to use under good laboratory practice (GLP) and non-GLP conditions. Moreover the methods must be user friendly enough to be easily employed by farmers in the field, grain dealers at the silo, and customs officials at the borders. Therefore, robust, high quality, user friendly protein detection methods and commercial kits are useful and necessary.
While immunoassays are well-known in the art, developing robust, high quality, validated ELISA methods that are reproducibly able to detect a particular transgenic protein product in an array of plant tissue in both lab and field settings is neither trivial nor routine. Still more challenging is to find antibody pairs that are particularly well suited to the development of a lateral flow strip ELISA for detecting Cry1Ca expressed by a transgenic event in a crop.
SUMMARY OF THE INVENTION
The present invention provides a panel of monoclonal antibodies (Table 1) and the hybridoma cell lines that produce them. The table below lists the hybridoma line designations and their corresponding ATCC deposit designations that were deposited with the American Type Culture Collection in accordance with the terms of the Budapest Treaty. The invention includes a method for identifying the presence of an Cry1Ca enzyme comprising: a) immobilizing a first monoclonal antibody of Claim 1 onto an assay surface then washing said assay surface; b) contacting said assay surface with a liquid suspected of containing Cry1Ca for a period of time sufficient to allow binding then washing said assay surface; c) contacting said assay surface with a different second antibody of the invention conjugated to a reporting group for a period of time sufficient to allow binding of said second conjugated monoclonal antibody then washing said assay surface; and, d) detecting the presence or absence of said reporting group.
The invention also includes methods of using the claimed mAbs for isolating or detecting Cry1Ca comprising: a) immobilizing said antibody onto a surface; b) contacting said immobilized antibody with a mixture containing Cry1Ca; c) separating said immobilized antibody bound to Cry1Ca from said mixture; and d) recovering Cry1Ca by removing the antibody-bound Cry1Ca from said immobilized antibody.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a Cry1Ca standard curve. Seven concentrations of the reference Cry1Ca protein were tested and were shown to have linearity using the quadratic curve fitting analysis. Acceptable correlation was shown by an r 2 value of 0.999.
FIG. 2 is a comparison of amino truncated and full length Cry1Ca ELISA standard curves showing the slope difference between the two standards.
DETAILED DESCRIPTION
The present invention encompasses the mAbs listed in Table 1, and the hybridomas that produce the mAb, that specifically bind with Cry1Ca core toxin.
TABLE 1
Hybridoma/mAb
ATCC Deposit
ATCC Deposit
Designation
Designation
Date
3-34
PTA-121061
5 Mar. 2014
4-39
PTA-121062
5 Mar. 2014
4-45
PTA-121063
5 Mar. 2014
4-40
PTA-121064
5 Mar. 2014
4-41
PTA-121065
5 Mar. 2014
4-42
PTA-121066
5 Mar. 2014
These mAbs are surprisingly well suited for detecting both Cry1Ca holotoxin and Cry1Ca core toxin expressed by transgenic events in a variety of plants and plant tissues. The invention further provides quantitative and qualitative immunoassays using the immunoglobulins of the invention. A two-mAb sandwich ELISA was validated for the determination of Cry1Ca protein in corn leaf tissue. The full-length Cry1Ca reference standard curve from 1.525-100 ng/mL was determined to have linearity based on the quadratic fit analysis and a correlation of 0.999. The Cry1Ca ELISA is accurate when comparing samples for similar protein levels by two analytical methods (ELISA and western blot analysis) as well as recovery of Cry1Ca protein when compared to the theoretical concentration of the protein spiked into corn matrix. This assay also precisely determined protein levels over multiple assay days. When testing corn samples, measurements of protein levels were parallel over five dilutions, so unbiased measurements will not occur based on the dilution needed for corn samples.
The invention also includes a method of using the claimed antibodies for identifying the presence of Cry1Ca in a biological sample comprising: a) immobilizing said antibody onto an assay surface; b) contacting said assay surface with a liquid suspected of containing Cry1Ca and washing said assay surface with a suitable solution; c) contacting said assay surface with an anti-Cry1Ca antibody labeled with a reporting group and washing said assay surface with a suitable solution; d) detecting the presence of said reporting group.
The invention further includes an analytical method for the quantitative determination of Cry1Ca toxin expressed in transgenic plants, especially soybean and cotton plants. The Cry1Ca protein is extracted from soybean samples with a PBST (phosphate buffered saline solution containing 0.05% Tween™ 20) solution. The extract is centrifuged; the aqueous supernatant is collected and diluted. An aliquot of the diluted sample is incubated with enzyme-conjugated anti-Cry1Ca monoclonal antibody in the wells of an anti-Cry1Ca polyclonal or monoclonal antibody-coated plate in a sandwich ELISA format. Both antibodies in the sandwich pair capture the Cry1Ca protein in the sample. At the end of the incubation period, the unbound reagents are removed from the plate by washing with PBST. The presence of Cry1Ca is detected by incubating the enzyme conjugate with an enzyme substrate, generating a colored product. Since the Cry1Ca is bound in the antibody sandwich, the level of color development is proportional to the concentration of Cry1Ca in the sample (i.e., lower protein concentrations result in lower color development). The absorbance at 450 nm minus absorbance at a reference wavelength (such as 650 nm) is measured using a plate reader. A calibration curve is estimated from 7 standard concentrations using a quadratic regression equation. This Cry1Ca ELISA is specific and sensitive enough for the quantitation of Cry1Ca in plant tissue sample extracts. In addition the antibodies of the invention may be used to confirm the presence of Cry1Ca using a standard western blotting procedure.
The preparation of antibodies against proteins of interest is well known in the art. See Galfre and Milstein, Methods in Enzymology, Vol. 73, Academic Press, New York (1981); James W. Goding, Monoclonal Antibodies: Principles and Practice, Academic Press, Orlando, Fla. (1986); Current Protocols in Molecular Biolopy, F. M. Ausubel, et al. ed., Wiley Interscience, New York, (1987).
To prepare antibodies reactive with a protein of interest, the protein must be first enriched or purified. Relatively crude antigenic preparations of the protein may be used for immunization purposes. However, highly purified protein is required to determine accurately if hybridomas are producing the sought after monoclonal antibodies or to assay the antibody titers of immune serum.
Once the Cry1Ca has been isolated, antibodies specific for Cry1Ca may be raised by conventional methods that are well known in the art. Repeated injections into a host of choice over a period of weeks or months will elicit an immune response and result in significant anti-Cry1Ca serum titers. Preferred hosts are mammalian species and more highly preferred species are rabbits, goats, sheep and mice. Blood drawn from such immunized animals may be processed by established methods to obtain antiserum (polyclonal antibodies) reactive with Cry1Ca. The antiserum may then be affinity purified by adsorption to Cry1Ca according to techniques known in the art. Affinity purified antiserum may be further purified by isolating the immunoglobulin fraction within the antiserum using procedures known in the art. The resulting material will be a heterogeneous population of immunoglobulins reactive with Cry1Ca.
Anti-Cry1Ca mAbs are readily prepared using purified Cry1Ca. Methods for producing mAbs have been practiced for several decades and are well known to those of ordinary skill in the art. Repeated intraperitoneal or subcutaneous injections of Cry1Ca in adjuvant will elicit an immune response in most animals, especially mice. Hyperimmunized B-lymphocytes are removed from the animal and fused with a suitable fusion partner cell line capable of being cultured indefinitely. Numerous mammalian cell lines are suitable fusion partners for the production of hybridomas. Many such lines are commercially available from the ATCC and commercial suppliers.
Once fused, the resulting hybridomas are cultured in a selective growth medium for one to two weeks. Two well known selection systems are available for eliminating unfused myeloma cells or fusions between myeloma cells from the mixed hybridoma culture. The choice of selection system depends on the strain of mouse immunized and myeloma fusion partner used. The AAT selection system, described by Taggart and Samloff, Science 219, 1228 (1982), may be used; however, the HAT (hypoxanthine, aminopterin, thymidine) selection system, described by Littlefield, Science 145, 709 (1964), is preferred because of its compatibility with mouse cells and fusion partners mentioned above.
Spent growth medium is then screened for immunospecific mAb secretion. Enzyme linked immunosorbant assay procedures are best suited for this purpose; though, radioimmune assays adapted for large volume screening are also acceptable. Multiple screens designed to consecutively pare down the considerable number of irrelevant or less desired cultures must be performed to isolate the small percentage of mAbs of the instant invention. Cultures that secrete mAbs reactive with Cry1Ca were isotyped using commercially available assays.
Hybridoma cultures which secrete the sought-after anti Cry1Ca mAbs should be sub-cloned several times to establish monoclonality and stability. Well known methods for sub-cloning eukaryotic, non-adherent cell cultures include limiting dilution, soft agarose and fluorescence activated cell sorting techniques. After each subcloning, the resultant cultures must be re-assayed for antibody secretion and isotype to ensure that a stable antibody-secreting culture has been established.
The claimed anti-Cry1Ca antibodies can be immobilized to a surface so that some of the antibody binding site remains exposed and capable of binding Cry1Ca. A wide assortment of schemes for immobilizing antibodies has developed over the past few decades. Immobilization can be accomplished by covalently coupling the antibody directly to the desired surface or by bridging the antibody to the surface.
CNBr and carbodiimide coupling of antibodies to polysaccharide based beads such as Sepharose® (Pharmacia, Piscataway, N.J.) are illustrative of direct coupling schemes that are consistent with the invention. Direct couplings generally do not orient the antibodies in any particular fashion; however, some types of direct couplings are able to reproducibly orient the antibody on the immobilizing substance.
Preferred coupling schemes orient the antibody such that its antigen binding regions remain exposed. One such scheme utilizes the natural carbohydrate found on the heavy chains of the antibody. By first oxidizing the carbohydrate moieties to the corresponding aldehydes then reacting the aldehyde with a primary amino group on the surface, it is possible to link the antibody in an advantageous orientation.
Many types of bridges are possible and include small organic linkers which covalently bind the antibody to the immobilizing substance. Such spacer arms are acceptable and preferably should not interact with proteins once the bridge has been formed.
The above discussion is in no way meant to limit the scope of the invention. Numerous other well known schemes for linking antibodies to immobilizing substances are consistent with the invention.
It is well known that antibodies labeled with a reporting group can be used to identify the presence of antigens in a variety of milieus. Antibodies labeled with radioisotopes have been used for decades in radioimmune assays to identify, with great precision and sensitivity, the presence of antigens in a variety of biological fluids. More recently, enzyme labeled antibodies have been used as a substitute for radio-labeled antibodies in the popular ELISA.
Antibodies of the present invention can be bound to an immobilizing substance such as a polystyrene well or particle and used in immunoassays to determine whether Cry1Ca is present in a test sample. In this embodiment of the invention, a sample is contacted with the immunoaffinity surface and allowed to incubate. After a washing step, any Cry1Ca that has bound to the immunoaffinity surface is detected by contacting the surface with another antibody of the invention labeled with a reporting group.
The use of lateral flow strips or immunochromatographic strips with the claimed antibodies and assay methods is consistent with the invention. Lateral flow assays are well known in the art. See for example U.S. Pat. No. 6,485,982. In this mode lateral flow tests can be used for qualitative or semi-quantitative detection of Cry1Ca alone or simultaneously with other analytes. Lateral flow tests are the simplest to use of all the test formats described herein and are particularly useful in field settings where plant material is quickly extracted into a solution and tested on a lateral flow strip. In this mode it is only necessary to place the lateral flow strip into a liquid sample or to apply the liquid sample to the lateral flow strip and read the results after a predetermined time. All lateral flow tests should incorporate either a procedural control line or a sample control line that is used to validate the test result. Appearance of two lines, therefore, indicates a positive result, while a valid negative test produces only the control line. If only the test line appears, or if no lines appear, it is invalid.
A typical lateral flow test strip consists of four main components; a sample pad upon which the test sample is applied, a conjugate pad that contains antibodies of the present invention conjugated to colored particles (typically colloidal gold particles, or latex microspheres); a reaction membrane such as a hydrophobic nitrocellulose or cellulose acetate membrane onto which a different antibody of the invention is immobilised in a line across the membrane as a capture zone or test line; and, a waste reservoir designed to draw the sample across the reaction membrane by capillary action.
The components of the lateral flow strip are normally fixed to an inert backing material and may be presented in a simple dipstick format or within a plastic casing with a sample port and reaction window showing the capture and control zones. In another mode of the assay embodiment, a test sample suspected of containing Cry1Ca is dried onto a surface, forming an immobilized test sample. A labeled antibody of the invention is then contacted with the immobilized test sample and allowed to incubate. If the sample contains Cry1Ca, the labeled antibody will bind to the immobilized Cry1Ca. This method can also be done using an unlabeled antibody of the invention followed by a labeled secondary antibody that binds to an antibody of the invention which has already bound to Cry1Ca. After washing, the immobilized test sample is measured to detect the presence of any reporting groups.
Reporting groups are typically enzymes such as alkaline phosphatase, horseradish peroxidase or beta-D-galactosidase. Suitable substrates produce a color change when reacted with the enzyme. In so doing, measurements of the color intensity can be quantitated using a spectrophotometer. If the reporting group is a radioisotope, an appropriate gamma or beta ray detecting instrument can be used to quantitate the reporting group. The intensity of the reporting group directly correlates, with the amount of Cry1Ca in the test sample.
The following examples will help describe how the invention is practiced and will illustrate the characteristics of the claimed anti-Cry1Ca antibodies and assays.
EXAMPLE 1
Immunogen Preparation
Full length Cry1Ca holotoxin was produced using a Pseudomonas fluorescens protein expression system. See for example Retallack et al., Protein Expression and Purification ; Vol 81, 2, pp 157-165; February 2012. Five to Ten grams cell paste was used to prepare protein samples. For high expressers (up to 0.5 g/l), 5 g of cell paste was sufficient. For low expressers, typically 10 g of cell paste was processed. The host cells were suspended in 10-20 volumes or 100 ml solution containing 20 mM Tris-HCl, pH 8, 150 mM NaCl, 5% Glycerol, 5 mM EDTA, 1 mM DTT with a homogenizer (Pro Scientific Inc., Model Pro300A) and sonicated on ice for 10 min (Branson Sonifier Model 450). Supernatant containing soluble proteins was discarded after 20 min centrifugation at 12 k rpm. The pellet containing target proteins was washed in 100 ml fresh solution (as before), and then centrifuged. This process was repeated 2-3 times until the recovered inclusion body (IB) was clear. 10 ml of 50 mM CAPS, pH 11 solution containing 10 mM DTT and 4 M Urea was added per gram of IB (wet weight), and the protein was solubilized at room temperature for approximately 2 hours on a rocking plate. The sample was centrifuged at 12 krpm for 20 min and the supernatant was transferred into a SnakeSkin™ pleated dialyze tubing (Thermo Scientific, 10 kDa cut-off) and dialyze against 1 L of 50 mM CAPS, pH 11 with 10 mM DTT at 4° C. overnight. The sample was centrifuged at 12 k rpm for 20 minutes to remove any precipitation.
The supernatant was collected and applied onto a 5 ml HiTrap™ Q (GEHC, Fast Flow or High Performance column) at 5 ml/min. The column was washed for 2-3 column volume, then eluted using 0-100% buffer B (1 M NaCl in buffer A, equal to 50 mM CAPS, pH 11, 10 mM DTT) over 20 minutes while 2.5 ml fractions were collected. Peak elutes were then analyzed by SDS-PAGE. Cry1Ca eluted from 20-45 mS/cm of salt, corresponding to fraction number 10-20, and 20 μl of sample was withdrawn for gel analysis. The majority of earlier eluted peaks containing Cry1Ca core protein were pooled, and transferred into a Millipore concentration unit with 50 KDa cut-off filter, and centrifuged at 4000 rpm at room temperature for 5-15 minutes that resulted in a final sample volume of approximately 1 ml. The sample was injected onto a 24 ml Superdex™ 200 column (10/300 dimension) at 1 ml/min. The size column was run with 20 mM CAPS, pH 11, 0.1 M NaCl, and 10 mM DTT buffer, and 1 ml fractions were collected. 20 μl of sample aliquot was analyzed on SDS-PAGE for the fractions covering the major peaks. Typically higher oligomer eluted at 13-14 minutes, and smaller monomeric target protein eluted at or after 16 minutes. The purified Cry1Ca toxin was pooled, and stored at −20° C.
Amino truncated Cry1Ca core toxin (residues 29-628) was prepared for further assay validation studies by trypsin cleavage of the holotoxin. A sample of purified Cry1Ca holotoxin showed a positive signal of the expected size by western blot using anti-Cry1Ca polyclonal antibody. Bioactivity of the purified Cry1Ca holotoxin and amino truncated core toxin was confirmed by an insect bioassay using neonate Diamondback moth larvae fed on Cry1Ca spiked diet.
EXAMPLE 2
Hybridoma Preparation
Mice were immunized with purified Cry1Ca, and standard hybridoma fusion techniques were used to prepare a panel of hydridomas expressing anti Cry1Ca monoclonal antibodies. Samples of spent tissue culture media were removed aseptically from each well containing a hybridoma culture and assayed for Cry1Ca reactivity using the following antibody capture ELISA method. Microtiter wells were coated with a solution of 1-10 μg/mL of purified Cry1Ca. The wells were washed and samples of spent tissue media were placed in the wells and allowed to incubate. The wells were washed and horseradish peroxidase-labeled goat anti mouse antiserum was added and allowed to incubate. The plates were washed, substrate was added to develop a color reaction and the plates were read for OD (optical density). Wells with high OD readings were mapped back to culture wells containing the hybridomas. The Cry1Ca antibody positive cultures were continually screened for antibody production to assure growth stability and antibody production as the cultures were expanded. Several rounds of limiting dilution cloning were performed to establish true monoclonality for each culture. Further assays on antibody positive clones were conducted to determine the suitability of each antibody for use in the presently claimed detection methods for field use with plant material. The monoclonal antibodies were screened for specificity to Cry1Ca holo and core toxin. All the antibodies were tested for cross-reactivity and none were found to cross react with Cry1Ab, Cry1Ac, Cry1Be, Cry1Da, and Cry1F.
EXAMPLE 3
Quantitative ELISA Validation Study
Antibody 4-40 was used as the capture antibody and was coated on a 96 well microtiter plate at a concentration of 1 ug/ml in PBST (phosphate buffered saline solution containing 0.05% Tween™ 20) with 0.75% ovalbumin (PBST/OVA) then stored under refrigeration. The detection antibody, 4-42, was conjugated to horseradish peroxidase (HRP) using standard techniques. An assay kit consisting of an antibody coated microtiter plate, liquid HRP conjugate of 4-42 (1×), enzyme substrate solution, and standard reaction stopping agent was prepared to use in this validation experiment.
Linearity testing consisted of testing the Cry1Ca kit with a Cry1Ca holotoxin protein standard curve diluted in buffer to determine if the curve was linear across all concentrations. A coated anti-Cry1Ca assay plate was brought to room temperature (about 30 minutes). A Cry1Ca protein standard (100 ng/mL in PBST) was prepared. PBST was used as the dilution buffer for this experiment unless otherwise noted.
200 uL of the Cry1Ca standard was added in triplicate to Row A, Columns 10-12. 100 uL of PBST buffer was added to remaining wells in Columns 10-12. A 2-fold serial dilution was performed down the columns of the plate by taking 100 μL of the first standard and adding to the next well containing buffer that produced a Cry1Ca standard curve of 100, 50, 25, 12.5, 6.25, 3.125, and 1.4525 ng/mL. The plate was sealed and shaken at room temperature for 1 hour using a plate shaker. The plate was washed four times with PBST using a QuadraWash™ 2 plate washer, (Tomtec).
After washing, 100 μL of Cry1Ca/HRP enzyme conjugate was added to the wells of the plate. The plate was sealed and shaken at room temperature for 30 minutes. The plate was then washed using the plate washer. 100 μL of HRP substrate solution was added to the wells of the plate and incubated for 15 minutes at room temperature. 100 μL of stop solution (0.4 M H 2 SO 4 ) was added to the wells of the plate. The plate was then read at 450 nm with a SpectraMax™ plate reader (Molecular Devices).
The reference Cry1Ca standard curve (100, 50, 25, 12.5, 6.25, 3.125, and 1.4525 ng/mL) showed that these concentrations were linear based on quadratic fit analysis (FIG. 1 ). This linearity was determined based on the correlation (r 2 ) value being 0.999. This curve was used for all subsequent testing by ELISA for this validation.
The assay above was repeated using truncated Cry1Ca core toxin and was compared to the holotoxin results ( FIG. 2 ). Due to the size difference of approximately 100% between holo and core toxins, the slope of the full length toxin was markedly different than the slope of the core toxin. This level I validation study demonstrated ELISA assays for detecting either Cry1Ca holo or core toxin with defined levels of performance needed to provide a high degree of confidence in the results produced.
The precision of these methods were determined using the results of standard ‘spike-in’ experiments over multiple days. The standards were distributed into single-use vials and stored at −80° C. until used for testing. The standard deviations and percent coefficient of variation were calculated for each of six total spike-in replicates. The coefficient of variation was calculated for each level of fortification with an acceptable range of <20% between the expected concentrations of 50-0.80 ng/ml as shown in Table 2.
TABLE 2
Values in ng/ml
Expected
Precision
concentration
Rep 1
Rep 2
Rep 3
Rep 4
Rep 5
Rep 6
% CV
200
150
280
180
160
200
120
30%
100
98
110
171
88
110
93
27%
50
64
58
58
45
54
50
12%
25
27
30
29
25
25
22
11%
13
13
14
13
12
11
11
10%
6.3
7.3
7.5
6.8
6.1
6.1
5.5
12%
3.1
3.4
4.1
3.5
3.3
3.3
3.2
9%
1.6
2.2
2.2
1.9
1.8
1.7
1.6
13%
0.80
1.2
1.1
0.93
0.89
0.88
0.81
15%
0.40
0.52
0.43
0.28
0.32
0.33
0.35
24%
0.20
0
0
0
0
0
0.05
245%
EXAMPLE 4
Selectivity/Matrix Effect
Null transgenic corn leaf tissue was tested for matrix interference with the Cry1Ca standard. A mixture of corn leaf tissue was placed into 50 mL conical tubes with 40 mL of Extraction Buffer (PBST+5 ul/ml of Plant Protease Inhibitors Cat # P9599 Sigma) and 40 Daisy™ BBs (4.5 mm). The tubes were shaken for 3 minutes in a modified paint shaker then centrifuged for 10 minutes at 3600 rpm. The supernatant was removed, placed on ice and tested for total soluble protein using the Pierce BCA Protein Assay Kit (Cat # 23227, Thermo Scientific). Once the total protein concentration was determined, the matrix was diluted to 0.24 mg/mL in PBST as used as the corn matrix.
Purified Cry1Ca protein standard was diluted to 100 ng/mL in corn matrix solution and 100 μL was added to the wells of a Cry1Ca coated microtiter assay plate in triplicate in Row A, Column 10-12. 100 μL of corn matrix (without Cry1Ca standard) was added to the remaining wells of the plate. A 2-fold serial dilution was performed down the columns of the assay plate and was tested using the ELISA kit from Example 3. The matrix effect was determined by the % recovery determined by the ELISA for each standard concentration compared to the theoretical protein amount added to the matrix. The reference Cry1Ca spiked into the corn matrix was used to determine if Cry1Ca could be detected at acceptable levels when in the presence of corn matrix. A corn sample would normally be diluted 1:25, therefore the total extractable soluble protein concentration in the sample is 0.24 mg/mL. This concentration will be used for all tests with corn matrix.
Based on the ELISA results, each of the seven Cry1Ca standard concentrations had acceptable signal (80-120%) as compared to the theoretical protein spiked into the matrix (Table 3). Thus, there was no matrix effect observed in any of the Cry1Ca standards with the corn matrix concentration tested.
TABLE 3
Actual Cry1Ca
Theoretical Cry1Ca
Conc. in Corn
% Recovery of
Conc. (ng/mL)
Matrix (ng/mL)
Cry1Ca
100
115
115
50
48
96
25
23.5
94
12.5
12.6
101
6.25
6.9
110
3.125
3.3
106
1.5625
1.6
102
EXAMPLE 5
Accuracy
The accuracy of the assay was determined by comparing ELISA results with a western blot. Three leaf samples from corn plants genetically engineered to express Cry1Ca holotoxin were extracted as described above. The samples were then centrifuged for 5 minutes at 3600 rpm. 100 μL of supernatant was removed and placed on ice until use in ELISA. 200 μL of extraction buffer was added to the samples, and the extraction process was repeated. The supernatants from both extractions were then pooled together. The samples were diluted at 2, 4, 8, 16, and 32 dilutions in duplicate and added to an ELISA plate. Cry1Ca standard was prepared and added to the plate in duplicate starting at 100 ng/mL. The ELISA assay was then run based on the methods above. All dilutions for each sample were averaged together to get the average ng/mL value for each corn sample.
Three corn samples were tested by western blot analysis in duplicate using the extracts from the ELISA testing above. After the supernatant was collected, 4×loading buffer (NUPAGE LDS Sample Buffer, Invitrogen) containing 400 mM dithiothreitol (DTT) was added to the sample extract to make the final concentration 1×. The samples were heated for 5 minutes at 90° C. The samples, full-length Cry1Ca protein standard (20 ng/lane, 10 ng/lane), truncated Cry1Ca protein standard (20 ng/lane, 10 ng/lane), and negative corn matrix were loaded into a 4-12% Bis-Tris NUPAGE Mini Gel (Invitrogen). Once each lane of the gel was loaded, the gel box was run at 200V for 45 minutes. After gel separation, the proteins were transferred to a membrane by tank transfer. The blot module (Xcell II Blot™ module, Invitrogen) was assembled in the following order: bottom (negative electrode) part of the module, 3 pre-wet filter pads, 1 pre-wet filter paper, mini gel, membrane (PVDF, Invitrogen), 1 pre-wet filter paper, 3 pre-wet filter pads, and the top (positive electrode) part of the module. The transfer sandwich was then placed in the transfer tank, and 1×Transfer Buffer (Invitrogen) was added to the inner and outer chambers of the tank. The gel was transferred at 5V overnight in the cold room. After transfer, the membrane was blocked with ECL Blocking Agent (Amersham Biosciences) for 60 minutes at room temperature while shaking at 50 rpm. The blocking solution was removed, and the primary antibody (rabbit anti-Cry1Ca truncated), diluted to 1 ug/mL in blocking buffer, was added to the membrane for 1 hour at room temperature with shaking. The primary antibody was removed, and the blot was rinsed two times with PBST and washed two times for 5 minutes with PBST. After washing, the secondary antibody (goat anti-rabbit HRP, KPL), diluted 1:5000 with PBST, was added to the membrane and incubated for 1 hour at room temperature while shaking. The secondary antibody was then removed and the membrane was rinsed 3 times with PBST, washed 4 times for 5 minutes each with PBST, and then rinsed 3 times with 1×PBS. After washing, the blot was subjected to 4 mL of chemiluminescent substrate (Pierce SuperSignal West Pico Luminol Enhancer™ and Stable Peroxide Solution) for 4 minutes. The substrate was removed, and the blot was wrapped in plastic wrap. The blot was then taken into a dark room and exposed to film to detect the proteins present on the gel. Once the protein image was displayed on the film, the film was scanned on a Syngene XR Imager (Syngene) and densitometry was determined on the standard and sample bands using the Quantity One™ software (Bio-Rad). The results are shown in Table 4.
TABLE 4
Samples
ELISA (ng/mL)
Western (ng/mL)
% Difference
Plant 1
387
428
10.8
Plant 2
431
338
21.5
Plant 3
462
531
14.9
EXAMPLE 6
Parallelism
The Cry1Ca assay was tested for parallelism to ensure the claimed antibodies supported an assay in which multiple serial dilutions of samples would not result in a biased measurement of Cry1Ca-expressing corn plants. Six leaf samples of corn genetically modified to express Cry1Ca were tested by ELISA. It was found that for each sample, five dilutions (1:4, 1:8, 1:16, 1:32, and 1:64) fell within the quantitative range of the standard curve, and the CV (coefficient of variation) of the quantified results was less than 20% as shown in Table 5. Each sample was tested in triplicate, and an average concentration was determined for each dilution within the individually tested sample. SD corresponds to standard deviation, which is used to determine % CV. There was no trend of increasing or decreasing estimates of the protein concentration over the dilution range tested. Thus, the Cry1Ca ELISA demonstrated parallelism across five dilutions for Cry1Ca-positive corn plants.
TABLE 5
Dilution
Sample 1
Sample 2
Sample 3
Sample 4
Sample 5
Sample 6
1:4
508.191
508.191
508.191
508.191
508.191
508.191
1:8
470.131
628.031
323.393
394.814
440.835
622.827
1:16
438.126
477.366
331.533
396.013
412.269
495.308
1:32
481.099
512.159
369.047
407.615
450.533
532.541
1:64
526.427
532.907
401.336
449.713
498.186
578.982
Average
484.7948
531.7308
386.7
431.2692
462.0028
547.5698
SD
34.23188
57.37556
74.72797
48.4475
40.29782
52.81624
CV
7.061106
10.79034
19.32453
11.2337
8.722419
9.645573 | Described herein are murine monoclonal antibodies and methods useful for determining and quantitating the presence of Cry1Ca delta endotoxin. The claimed antibodies specifically bind the core toxin region making them suitable for detecting the native full length Cry1Ca toxin as well as the amino core toxin and N-terminal 29 residue truncated forms. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to the field of light fixtures and more specifically, to a recessed light fixture.
[0003] 2. Background of the Invention
[0004] Various recessed downlight light fixtures have been designed for use in ceilings. Usually such fixtures create problems when it is necessary to relamp or reballast the fixture because of the difficulty encountered in removing the light fixture from the ceiling or gaining access to the light fixture's internal components.
[0005] Recessed ceiling light fixtures known in the art use different means of securing their components to each other and to a ceiling structure. For example, U.S. Pat. No. 5,567,041 discloses a recessed ceiling light having an outer housing, which includes an integral flange, and an inner housing, which is secured in position in the outer housing by spokes. The outer housing includes a cylindrical support ring to which the outer lens is secured to the outer housing by a threaded arrangement. Thus, the components of this light fixture are held in place by a complex combination of spokes and threaded fittings.
[0006] U.S. Pat. No. 5,826,970 discloses a recessed ceiling light fixture that includes an outer housing, which is supported in the sheet rock of the ceiling by support arms, a conical cup, which includes a peripheral flange, and an inner member, which is inserted into the conical cup. The inner member is supported within the outer housing by springs, while the conical cup is supported on the outer housing by a friction fit. Thus, the components of this light fixture are held in place in the ceiling by a combination of support arms, spring members, and a friction fit.
[0007] U.S. Pat. No. 5,738,436 discloses a modular lighting fixture that uses a spring member to secure the reflector module to the housing. U.S. Pat. No. 5,941,625 discloses a recessed light fixture that uses a spring clip to secure the light fixture to its housing and to a ceiling structure. U.S. Pat. No. 5,609,414 discloses a recessed lighting fixture that uses a pair of retaining clips and other components to secure the light fixture to its housing and to a ceiling structure.
[0008] In addition to the above, there are known light fixtures that are difficult to assemble and disassemble due to the intricate connecting means of their components. In such instances, the sheet rock and layer of spackle abutting the light fixture are damaged when a user has to pull on the light fixture or inordinately twist the light fixture to assemble or disassemble it. In addition, other known light fixtures are preset for use in ceilings or similar structures containing ½-inch, ¾-inch or 1-inch sheet rock.
[0009] Thus, the prior art does not teach or suggest a recessed light fixture that includes a structure that makes assembly and disassembly of the light fixture simple.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a recessed light fixture that includes features that make assembly and disassembly of the light fixture simple.
[0011] It is another object of the present invention to provide a recessed light fixture that includes features that make relamping and reballasting of the fixture simple.
[0012] It is another object of the present invention to provide a light fixture that can be used with sheet rock of different sizes.
[0013] According to one aspect of the present invention, the light fixture includes an outer member, a middle member, and an inner member, each of which has a generally cylindrical shape in the form of a ring. The outer member has a peripherial circular flange at one end and a threaded interior surface. The middle member has a similar flange at one end and a threaded male portion on its exterior surface. The outer member is connected to the middle member by threadedly engaging their respective thread surfaces.
[0014] The inner member has an exterior surface on which a plurality of grooves are formed therein, with the grooves extending transversely on its cylindrical wall. The middle member includes a plurality of openings for receiving a plurality of securing members, e.g. set screws, with each of the plurality of securing members having inner ends and being located such that these ends will be respectively received in the grooves, for securing the middle member to the inner member.
[0015] The above and other objects, features and advantages of this invention will be apparent to those skilled in the art from the following detailed description of illustrative embodiments of the invention, which is to be read in connection with the accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an exploded perspective view of a light fixture constructed in accordance with the present invention;
[0017] FIG. 2 is a perspective view of an assembled light fixture constructed in accordance with the present invention;
[0018] FIG. 3 is a side view showing the light fixture installed in a rectangular support assembly in a ceiling; and
[0019] FIGS. 4 and 5 are elevational views of the light fixture taken approximately 90° from each other.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] As mentioned above, the present invention is directed to a recessed light fixture, and in particular, to a light fixture including an outer ring, a middle ring, and an inner ring. The light fixture can be used in a variety of applications, but is preferably secured in a housing mounted in a ceiling, in a down-light application.
[0021] Referring now to the drawings in detail, and initially to FIG. 1 , the light fixture 10 includes an outer ring 12 , a middle ring 14 , and an inner ring 16 .
[0022] Outer ring 12 is cylindrically shaped and has a circular peripheral flange 18 formed at one end 20 thereof. Cylindrical ring 12 has a threaded inner surface 22 which is adapted to receive a corresponding externally-threaded outer surface 24 of middle ring 14 . The outer cylindrical surface portion 26 of ring 12 is generally smooth. Flat springs 28 having front and rear edges 30 , 32 , and top and bottom edges 34 , 36 , are secured to the outside surface of ring 12 by screws 45 , rivets, welding or other securing means known by those skilled in the art. Such securing means should be selected so as not to impede the threading of middle ring 14 into outer ring 12 .
[0023] Each spring 28 is preferably flat and has a general wing-shape. As seen in FIG. 1 , front and rear edges 30 , 32 of springs 28 taper towards the flange 18 . These springs are preferably used in pairs, with each pair preferably being located on diametrically opposed sides of outer ring 12 . As seen in FIGS. 3-5 , springs 28 serve to retain ring 12 and thus the entire lamp 10 in a protective sheet metal box 90 mounted in the ceiling 92 above the ceiling sheet rock 94 by supporting ring 12 on the edge of a circular hole 96 formed in the based 97 of box 90 . The box 90 is positioned in the ceiling so hole 96 aligns with a slightly larger hole 98 in sheet rock 94 . It protects the fixture 10 , ballast 100 and associated wiring from dust, heat and the like. The internal diameter of outer ring 12 is preferably 3-inches, but in any case is large enough to allow the fixture's light bulb 29 , electrical connections, wiring and ballast 100 to pass through the internal diameter of outer ring 12 for relamping and reballasting.
[0024] Middle ring 14 is also cylindrical in shape and has a circular peripheral flange 40 formed at its lower end 42 . As noted above, the outside surface of ring 14 is threaded to engage the threads on the inside surface of outer ring 12 . This threading feature allows the light fixture to be used with sheet rock of different sizes, preferably in the range of ½″ to 1{fraction (l/4)}″. Thus, as seen in FIGS. 3-5 , when ring 14 is threaded into ring 12 the thickness of the sheet rock is captured between the flange 40 of the ring 14 and the base 97 of box 90 to conceal the hole 98 and flange 18 of ring 12 .
[0025] Ring 14 has an inner surface 43 which is preferably smooth. Transverse, radial openings 44 are formed in the cylindrical portion of ring 14 . These openings 44 preferably comprise at least two circular ¼-inch threaded openings for respectively receiving set screws 45 , whose inner ends serve to secure the inner ring 16 in the fixture as described hereinafter. The inside diameter of middle ring 14 , like the inside diameter of outer ring 12 described above, also must be large enough to allow the fixture's light bulb 29 , electrical connections and wiring, and ballast 100 to pass through its internal diameter for relamping and reballasting.
[0026] Inner ring 16 is also generally cylindrical and has an outer surface 52 , an inner surface 54 , and top and bottom edges 56 , 58 . Inner ring 16 preferably does not have any flanges. The internal diameter of inner ring 16 is preferably not less than 2¾″. Inner surface 54 includes an internal circular ridge 55 (seen in FIG. 3 ) that the outer rim of the light bulb 29 rests on. Outer surface 52 has a first surface portion 53 and a second surface portion 59 of smaller outside diameter connected by a chamfered edge 57 . Surface 53 has a plurality of L-shaped grooves 60 formed therein. The upper end 61 of leg 62 of the grooves start at the chamfered edge 57 and extend on outer surface 53 of inner ring 16 toward its lower end 63 to the horizontal leg 66 of the L. Each groove has a second vertical leg 67 , shorter than the first leg 62 , joined to the other end of the horizontal leg 66 thereby to define a first elbow and second elbows in the grooves. The upper end of the second vertical leg 67 in each groove defines a stop or a secured position 72 for ring 16 in ring 14 . More specifically, when ring 16 is inserted into ring 14 , as seen in FIG. 1 , the upper ends of two legs 62 at chamfer 57 are aligned with the inner ends of the set screws 45 mounted in ring 14 so that upon insertion of the ring 16 those ends travel in the leg 62 of the groove to elbow 68 . At that position further insertion is prevented. The installer will then rotate ring 16 to allow the ends of the set screw 45 to travel in leg 66 to elbow 70 , where further rotation is prevented. By pulling the ring 16 downwardly at that point the set screw 45 will enter leg 67 and engage the stop surface 72 . At that position the inner ring 16 is supported on the set screws 45 and cannot fall out of the fixture. The width and depth of each groove 60 is preferably ¼-inch and {fraction (1/16)}-inch, respectively. However, a person of ordinary skill in the art will readily understand that the length, width, and size of these grooves and the other components of this light fixture may vary to fit a particular application.
[0027] Installation of light fixture 10 in the rectangular support structure or a sheet metal box 90 (as seen in FIG. 3 ), is performed by first slipping one of the springs 28 of outer ring 12 through the hole in the sheet metal box 90 , and then squeezing the other flat spring 28 to curve against the cylindrical position of the outer ring 12 to allow it to slip through the hole in the sheet metal box 90 . In that position the outer ring 12 can be pushed into the sheet metal box's housing 90 until flange 18 blocks further movement. The springs 28 open to their flat position once past hole 96 and lock outer ring 12 in place in housing 90 . Next, as seen for example in FIGS. 3-5 , middle ring 14 is threaded into outer ring 12 to a desired depth based on the thickness of the sheet rock. Then, to install inner ring 16 , grooves 60 are aligned with the ends of the set screws 45 . Inner ring 16 is pushed in until the set screws 45 move forward into first elbow 68 of the leg 62 . Then, middle ring 14 is held for example in one's left hand and inner ring 16 is rotated clockwise by one's right hand until the set screws 45 reach second elbow 70 of leg 64 . By gently pushing inner ring 16 downwardly, the set screws 45 move to the stop or secured position 72 , thereby locking inner ring 16 in middle ring 14 . An assembled light fixture 10 is seen in FIGS. 2, 4 and 5 .
[0028] Disassembly of light fixture 1 to relamp or reballast is done by performing the steps described above in reverse order. To remove inner ring 16 from its engagement with middle ring 14 , this apparatus uses a “lift and shift” movement. This is done by manually pushing ring 16 inwardly, thereby “lifting” it until the ends of the set screws 45 reach elbow 70 of leg 67 . The inner ring 16 is then rotated, i.e., “shifted” counterclockwise until it stops in first elbow 68 of the leg 62 . Inner ring 16 is then gently pulled downwardly, thereby releasing it from middle ring 14 . When inner ring 16 is released and pulled down further, the light bulb 29 is exposed, thereby allowing it to be changed. In addition, the wiring and ballast 100 can be pulled further downward through the opening in middle ring 14 thereby allowing the ballast 100 to be changed or repairs to be made to the fixture's internal components without removing the entire fixture from the ceiling.
[0029] Although an illustrative embodiment of the present invention has been described herein with reference to the accompanying drawings, it is to be understood that various changes and modifications may be effected therein by those skilled in the art without departing from the scope or spirit of this invention. | A light fixture including an outer ring, middle ring, and inner ring, each of which having generally a cylindrical shape. The outer ring has a flange at one end and a threaded female portion on an interior surface. The middle ring has a flange at one end and a threaded male portion on an exterior surface. When the outer ring is mated to the middle ring, the male portion is threaded into the female portion. The inner ring has a plurality of grooves on an exterior surface. The threaded male portion of the middle ring includes a plurality of openings for receiving a plurality of securing members, with each of the plurality of securing members capable of moving in each of the plurality of grooves and capable of securing the middle ring to the inner ring. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to an apparatus for securing a typewriter onto a mounting base for preventing it from being stolen.
There are many instances where typewriters are stolen, especially those placed on exhibition or display for sale, or even those on desks at offices or typing schools. In order to prevent the typewriter from being stolen, it has been suggested to provide a durable piece on the typewriter in such a manner that the piece protrudes from the outer periphery of the typewriter, and then to fix this piece onto the desk by means of bolts or the like. In this case, however, not only would it be possible easily to dismount the typewriter from the desk by the use of a tool, but is there also the drawback that the outer appearance of the typewriter is degraded due to the existence of the piece or the bolts protruded from the typewriter.
SUMMARY OF THE INVENTION
An object of the invention is to provide an apparatus for securing a typewriter for theft-prevention, which makes it impossible for another person to release the fixed typewriter and which causes no damage to the outer appearance of the typewriter.
According to an aspect of the invention, there is provided an apparatus for securing onto a typewriter-mounting base a typewriter comprised of a case which includes a bottom plate and a wall having an opening, and in which case a body with a printing function is received, and a cover which is attached to said case and closes said opening, so that when said cover is opened, a portion of said bottom plate is exposed, the apparatus comprising locking means for locking said cover to said case by means of a lock in a state wherein said cover is closed, and fastening means which, when said cover is opened, fastens the exposed portion of said bottom plate onto the mounting base through said opening, on a dismountable basis.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a typewriter fixed onto a desk using an apparatus according to an embodiment of the invention;
FIG. 2 is a side view of the typewriter shown in FIG. 1;
FIG. 3 is an enlarged perspective view of a locking device of the securing apparatus used in FIG. 1; and
FIG. 4 is an enlarged perspective view of a fastening device of the securing apparatus used in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1 and 2, an electric typewriter 10 has a case 20 in which a main body 18 having a keyboard 12, a ribbon cassette 14 and a typing element for printing the characters by striking and a drive mechanism (not shown) for the typing element are received. The case 20 is comprised of a bottom plate 22 and a wall 23 which has a side wall 24, and an upper plate 26 made integral with the side wall 24 and arranged to enclose the keyboard 12. On the side of the upper plate 26 or keyboard 12, an openable cover 28 is provided for replacement of a typewriter ribbon received in the ribbon cassette 14. The cover 28 has its rear portion opposite to the keyboard 12 side rockably supported, by means of a hinge pin 30, on a portion of the upper plate 26 of the case 20. The cover 28 has at its substantially central portion an opening 32 for insertion or removal of a sheet of paper to be typewritten. A pair of knobs 34 for manipulating the insertion and removal of the sheet of paper are provided in such a manner as to protrude from both sides of the cover 28. The knobs 34 are coaxially connected to both ends of a drum (platen) 36 used to press a typewriting sheet against the typing element. A main switch 38 for starting the electric typewriter is disposed at a rear portion of the case 20.
A locking device (a locking means) 39 for securely locking the cover 28 to the case 20 is disposed at one portion of the upper plate 26 located on either side of the keyboard 12. The locking device 39 is provided with a key portion 42 formed with a key groove 40 for insertion of a key at the time of locking and unlocking the locking device 39.
Four legs 46 formed of rigid material are provided at four corners of the bottom plate 22 of the case 20 through cushions 44, respectively, the bottom plate 22 being placed on a mounting base 48 with a specified space allowed to exist therebetween. Between the mounting base 48 and the bottom plate 22, a fastening device 50 is disposed for reliably fixing the typewriter 10 onto the mounting base 48 to be immovable.
As shown in FIG. 3, the locking device 39 has a pair of tongues 52 and 54 which are provided on both sides of the portion of the cover 28 closer to the keyboard 12, extending in the depthwise direction of the case 20. The tongue members 52 and 54 are each provided at one side with grooves 58 and 60 engageable with an arm 62 and one end portion 57 of a rod 56, respectively. The grooves 58 and 60 are formed in a direction transverse to the direction in which the cover 28 is rocked, substantially at right angles thereto so that the grooves are located substantially at the central positions of the tongue members, respectively. The rod 56 is connected at the other end portion to a tip end portion of the arm 62, a base end portion of which is connected to the key portion 42 so that, when the key (not shown) is inserted by an operator into the key groove 40 and turned, the base end portion may be interlocked with the key. The rod 56 is supported at its intermediate portion by a supporting piece 64 fixed to the upper plate 26 of the case 20. The rod 56 slides through a hole 66 formed in the supporting piece 64.
The fastening device or means 50 for fixing the bottom plate 22 of the electric typewriter to the mounting base 48 will now be described in detail with reference to FIG. 4.
The bottom plate 22 is formed with a fastening bore (third bore) 70 for insertion thereinto of a shaft (bolt) 68, at a position located substantially at a central portion between the drum (platen) 36 and a keyboard 12 and also located substantially at a middle portion of the travel locus of the ribbon cassette. At a position adjacent to the fastening bore 70, there is formed an insertion bore (second bore) 72 permitting a tip end portion of, for example, a driver to be inserted therethrough. A fastening member 74 having a convex central portion is firmly secured, by means of an adhesive agent 76, onto the mounting base 48. The convex portion of the fastening member 74 is formed substantially at its center with an adjusting bore (first bore) 78 for insertion therethrough of a shaft 68 formed with an external thread at one end portion thereof. The shaft 68 is adjustable within the adjusting bore 78. A circular plate 80 of larger diameter than that of the adjusting bore 78 formed in the fastening member 74, is formed at the lower end of the shaft 68 so as to be integral with this lower end. The circular plate 80 is at all times received within a space 82 defined between the fastening member 74 and the mounting base 48. The circular plate 80 has on its upper surface a recess 86 for receiving therein a tip end portion of a driver which has been inserted through the insertion bore 72 for the purpose of preventing, at the time of mounting a nut 84 onto the shaft 68, the rotation of the shaft 68 and the circular plate 80.
The operation of the securing apparatus for a typewriter according to the above-mentioned embodiment will now be described.
The fastening member 74 is firmly fixed in advance, by means of an adhesive agent, onto a desired position of the mounting base 48. Between the fastening member 74 and the mounting base 48, the circular plate 80 formed integrally with the shaft 68 is received in the above-mentioned space defined therebetween.
The cover 28 of the typewriter 10 is opened and the typewriter 10 is set so as to permit the shaft 68 to be fitted into the fastening bore 70 formed in the bottom plate 22. Next, the ribbon cassette and the typing element are moved to one side and a tool is inserted from between the keyboard 12 and the drum 36 to fit the nut 84 onto the shaft 68 for screw engagement, thereby fixing the typewriter 10 to the fastening member 74. At this time, the driver is inserted through the insertion bore 72 to prevent the rotation of the circular plate 80 at the time of fastening the nut onto the shaft 68. Since the adjusting bore 78 formed in the fastening member is made relatively large, it permits a slight movement of the typewriter 10.
Next, the cover 28 is closed and the tongue 54 is inserted into the case 20. Thereafter, the key (not shown) is inserted into the key groove 40 and is rotated. Thus, the arm 62 is swung in accordance with the rotation of the key portion 42 and is thus brought into engagement with the groove 58 formed in the tongue 52. Similarly, the rod 56 connected to the arm 62 is brought into fitting engagement with the groove 60 of the tongue 54. Accordingly, the cover 28 is locked in a closed state.
According to this embodiment, therefore, when it is desired to move the typewriter to another location, it is necessary to open the cover 28 by means of the key and then to unscrew the nut of the fastening device. In other words, the typewriter is double-locked, and simply by looking at it from the outside, it is not easy to locate the fastened portion of the typewriter. Consequently, it is possible to prevent another person from unlocking the locking device and releasing the fastening device to move or steal the typewriter.
Furthermore, since the typewriter is secured at the bottom plate of the case as well as at the interior of the cover, the outer appearance of the typewriter is not degraded.
Also, since the securing apparatus of this embodiment is removable, movement of the entire typewriter can be accomplished simply by opening the cover 28 by means of the key and removing the nut 84 of the fastening device 50. Then, the typewriter can be easily moved by the person possessing the key.
The present invention is not limited to the above-mentioned embodiment, but permits various modifications to be made without departing from the spirit of the invention.
The position for attaching the fastening device is not limited to the region between the keyboard and the drum (platen) but the invention permits the same effect to be obtained even if the position at which the fastening device is attached is located at the portion exposed when the cover is opened such as, for example, a portion located to the rear of the drum, or the portions located on both sides of the keyboard if the cover extends to both sides of the keyboard.
Further, in the above-mentioned embodiment, the fastening member is fixed, by means of an adhesive agent, onto the mounting base. But the invention is not so limited. For example, even when the fastening member is fixed onto the mounting base by means of a bolt or screw, the same effect is obtained.
In the above-mentioned embodiment, an electric typewriter was used as an example, but again the invention is not so limited. For example, even when the invention is applied to a manual typewriter, the same effect can be obtained.
Moreover, in the above-mentioned embodiment, a plug-in type key was used to fasten the locking device, but the invention is not limited thereto. For example, even when a number or dial key is used for fastening the locking device, the same effect can be obtained.
Further, in the above-mentioned embodiment, the fastening device includes a fastening member arranged to be fixed in advance onto the mounting base, but the invention is not limited thereto. For example, the fastening device may be of such a type wherein the bottom plate of the case of the typewriter is fixed directly onto the mounting base by means of a bolt. In this case, the mounting base is formed with a bore having an internal thread engageable with such a bolt. | An apparatus for securing a typewriter, includes a locking device for locking an outer case in a closed position and a fastening device for fastening a bottom plate of the case to a mounting base. When opened, the cover permits a portion of the bottom plate to be exposed. The fastening device is brought, from inside the case, into engagement with the bottom plate of the case through the exposed portion of the bottom plate, thereby locking the typewriter to the mounting base. The fastening device for the bottom plate cannot be released unless the locking device is unlocked by a key to open the cover. Accordingly, only a keyholder can unlock the locking device, thus preventing the typewriter from being stolen. Further, since the fastening device is engaged with the bottom plate of the typewriter case, the outer appearance of the typewriter is not degraded. | 1 |
FIELD OF INVENTION
[0001] The present invention relates to a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers: (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof, that are esterified with an alcohol, or mixtures thereof, and wherein at least a portion of carboxylic acid groups not esterified react with an amine. The invention further provides for a lubricating composition containing said copolymer. The invention further provides a method and use of lubricating composition in a mechanical device.
BACKGROUND OF THE INVENTION
[0002] Viscosity index improvers are known to be added to lubricating oil compositions to improve the viscosity index of the lubricant. Typical viscosity index improvers include polymers of methacrylates, acrylates, olefins (such as copolymers of alpha-olefins and maleic anhydride and esterified derivatives thereof), or maleic-anhydride styrene copolymers, and esterified derivatives thereof. However, such viscosity index improvers can have poor shear stability, too high a viscosity at low temperature, poor fuel economy, and poor non-dispersant cleanliness.
[0003] U.S. Pat. Nos. 7,254,249; 4,526,950; 6,419,714; 6,573,224; 6,174,843 6,419,714; and 4,526,950, and International Application WO 07/133,999 all disclose olefin copolymers for lubricating compositions
[0004] International publication WO2010/014655 A discloses a copolymer comprising units derived from monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof esterified with a primary alcohol branched at the β- or higher position, wherein the copolymer, prior to esterification, has a reduced specific viscosity of up to 0.08. The copolymer is useful to provide to a lubricant composition at least one of acceptable or improved shear stability, acceptable or improved viscosity index control, acceptable or improved low temperature viscosity and acceptable or improved oxidation control.
[0005] Antiwear agents such as phosphate alkyl ammonium chemistry have been employed in many transmission or axle lubricants as part of an antiwear package.
[0006] However, many of the amines disclosed may also detrimentally affect one or more of compatibility with mechanical device seals, metal corrosion, odour, handling, biodegradability, or oxidative cleanliness.
[0007] U.S. Pat. No. 3,484,504 discloses the addition reaction product of oxyalkylenated hydroxy-hydrocarbon phosphate or thiophosphate and polymeric reaction product containing basic nitrogen, the latter being (1) the reaction product of an unsaturated polymerizable ethylenic compound and an unsaturated polymerizable ethylenic compound containing basic nitrogen or (2) the reaction product of a polyamine or alkanolamine with the condensation product of an unsaturated polymerizable ethylenic compound and polycarboxylic acid, anhydride or ester thereof.
[0008] European Patent Application EP 1495098 A discloses a lubricating composition comprising a major amount of an oil of lubricating viscosity and a minor amount of a salt of a phosphorus acid ester and a nitrogen containing polyacrylate wherein the phosphorus acid ester is a phosphoric acid ester prepared from reacting a dithiophosphoric acid with an epoxide or a glycol to form an intermediate and further reacting the intermediate with a phosphorus acid or anhydride, wherein the nitrogen containing polyacrylate is prepared from at least one acrylate or methacrylate ester and a nitrogen containing monomer, wherein the polyacrylate is prepared from a combination of: a) methacrylic acid esters containing from 9 to 25 carbon atoms in the ester group, b) methacrylic acid esters containing 7 to 12 carbon atoms in the ester group and at least one nitrogen containing monomer, and wherein the salt is prepared by combining 0.5 to 10 parts by weight of the phosphorus acid ester with 99.5 to 90 parts by weight of the nitrogen containing polyacrylate.
SUMMARY OF THE INVENTION
[0009] An objective of the present invention is to provide an antiwear additive capable of utilization in a lubricating composition. Another objective of the present invention is to provide an additive capable of at least one of the following: reduced incompatibility with mechanical device seals, decreased metal corrosion, decreased wear, decreased odour, improved handling, improved biodegradability, improved oxidative cleanliness, improved low temperature performance, improved viscosity index, viscosity modifier performance, or improved antifoam performance.
[0010] In one embodiment the invention provides a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers: (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivative thereof, esterified with at least one alcohol, and wherein at least a portion of carboxylic acid groups are reacted with at least one amine.
[0011] As otherwise expressed, the invention provides a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof (typically carboxylic acid groups or an anhydride), that are esterified with an alcohol, or mixtures thereof, and wherein at least a portion of carboxylic acid groups not esterified react with an amine. Reaction with the amine may be referred to as capping with an amine. The amine is typically capable of forming a salt by reaction with a (thio)phosphate. The copolymer may have a measurable TBN (as determined by ASTM method D2986).
[0012] The copolymer of the invention may include 400 ppm to 4000 ppm, or 750 ppm to 3000 ppm of phosphorus.
[0013] As used herein the expression “(thio)phosphate” is intended to include a thiophosphate and a phosphate, and a thiophosphate also includes a dithiophosphate.
[0014] In one embodiment the invention provides a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers: (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof, that has been esterified, with an alcohol, or mixtures thereof, wherein the alcohol may be a primary alcohol and branched at the β- or higher position.
[0015] In one embodiment the copolymer may have, prior to esterification, a reduced specific viscosity of up to 0.08, or 0.02 to 0.08 (or 0.02 to 0.07, 0.03 to 0.07 or 0.04 to 0.06). Typically the RSV ranges described herein are based on the mean of three measurements made on the copolymer.
[0016] The copolymer may, instead of RSV, be defined in terms of weight average molecular weight. Typically the weight average molecular weight is measured on the final esterified copolymer, capped with an amine. The weight average molecular weight may be 5000 to 25,000, or 5000 to 20,000, or 10,000 to 18000 or 13,000 to 18,000.
[0017] The copolymer reduced specific viscosity (RSV) is measured by the formula RSV=(Relative Viscosity−1)/Concentration, wherein the relative viscosity is determined by measuring, by means of a dilution viscometer, the viscosity of a solution of 1.6 g of the copolymer in 100 cm 3 of acetone and the viscosity of acetone at 30° C. A more detailed description of RSV is provided below. The RSV is determined for the copolymer of an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof before esterification.
[0018] In one embodiment the copolymer described above comprises at least one ester group and a nitrogen containing group (such as amino-, amido- and/or imido-group), typically sufficient to provide 0.01 wt % to 1.5 wt (or 0.02 wt % to 0.75 wt %, or 0.04 wt % to 0.25 wt %) nitrogen to the copolymer.
[0019] In one embodiment the copolymer may be derived from monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof,
[0020] wherein 0.1 to 99.89 (or 1 to 50, or 2.5 to 20, or 5 to 15) percent of the carboxylic acid units esterified are functionalised with a primary alcohol branched at the β- or higher position,
[0021] wherein 0.1 to 99.89 (or 1 to 50, or 2.5 to 20, or 5 to 15) percent of the carboxylic acid units esterified are functionalised with a linear alcohol or an alpha-branched alcohol,
[0022] wherein 0.01 to 10% (or 0.1% to 20%, or 0.02% to 7.5%, or 0.1 to 5%, or 0.1 to less than 2%) of the carboxylic acid units are functionalised and have a nitrogen containing group with at least one of an amino-, amido- and/or imido-group (and may typically include an aminoalkyl ester, an aminoalkyl amide, or an aminoalkyl imide). In one embodiment the copolymer has a reduced specific viscosity of up to 0.08.
[0023] In one embodiment the invention provides a lubricant or lubricant concentrate obtained (or obtainable) by admixing the copolymer of the invention with (i) an oil of lubricating viscosity, and (ii) at least one other performance additives (as defined below).
[0024] In one embodiment the invention provides a method of lubricating a mechanical device comprising supplying to the mechanical device a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers: (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof, that are esterified with an alcohol, or mixtures thereof, and wherein at least a portion of carboxylic acid groups not esterified react with an amine.
[0025] In one embodiment the mechanical device may be a driveline device.
[0026] In one embodiment the invention provides for the use of the copolymer disclosed herein to provide to a lubricant composition with antiwear performance and at least one (or at least two, or all) of reduced incompatibility with mechanical device seals, decreased metal corrosion, decreased odour, improved handling, improved biodegradability, improved oxidative cleanliness, and improved antifoam performance.
[0027] In one embodiment the invention provides for the use of the copolymer disclosed herein in an axle oil to provide to a lubricant composition with antiwear performance and improved antifoam performance and optionally at least one (or at least two, or all) of reduced incompatibility with mechanical device seals, decreased metal corrosion, decreased odour, improved handling, improved biodegradability, and improved oxidative cleanliness.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The present invention provides a lubricating composition, a method and use as described above. In one embodiment the invention also provides a process for the preparation of the copolymer of the present invention.
[0029] A measurement correlating with molecular weight of the copolymer (or interpolymer such as an alternating copolymer) may be expressed in terms of the “reduced specific viscosity” of the copolymer which is a recognised means of expressing the molecular size of a polymeric substance. As used herein, the reduced specific viscosity (abbreviated as RSV) is the value typically obtained in accordance with the formula RSV=(Relative Viscosity−1)/Concentration, wherein the relative viscosity is determined by measuring, by means of a dilution viscometer, the viscosity of a solution of 1.6 g of the polymer in 100 cm 3 of acetone and the viscosity of acetone at 30° C. For purpose of computation by the above formula, the concentration is adjusted to 1.6 g of the copolymer per 100 cm 3 of acetone. A more detailed discussion of the reduced specific viscosity, also known as the specific viscosity, as well as its relationship to the average molecular weight of a copolymer, appears in Paul J. Flory, Principles of Polymer Chemistry, (1953 Edition) pages 308 et seq.
[0030] As used herein, the term “(meth)acryl” and related terms includes both acrylic and methacrylic groups.
The Copolymer
[0031] The copolymer of the invention prepared by the reaction of monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof.
[0032] The α-olefin may be a linear or branched olefin, or mixtures thereof. If the α-olefin is linear, the number of carbon atoms of the α-olefin may range from 2 to 20, or 4 to 16, or 8 to 12. If the α-olefin is branched, the number of carbon atoms of the α-olefin may range from 4 to 32, or 6 to 20, or 8 to 16. Examples of an α-olefin include 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene 1-octadecene, or mixtures thereof. An example of a useful α-olefin is 1-dodecene.
[0033] The ethylenically unsaturated carboxylic acid or derivatives thereof may be an acid or anhydride or derivatives thereof that may be partially esterified. When partially esterified, other functional groups include acids, salts, imides, and amides, or mixtures thereof. Suitable salts include alkali metal, alkaline earth metal salts, or mixtures thereof. The salts include lithium, sodium, potassium, magnesium, calcium salts, or mixtures thereof. The unsaturated carboxylic acid or derivatives thereof includes acrylic acid, methyl acrylate, methacrylic acid, maleic acid or anhydride, fumaric acid, itaconic acid or anhydride or mixtures thereof, or substituted equivalents thereof.
[0034] Suitable examples of the ethylenically unsaturated carboxylic acid or derivatives thereof include itaconic anhydride, maleic anhydride, methyl maleic anhydride, ethyl maleic anhydride, dimethyl maleic anhydride or mixtures thereof. In one embodiment the ethylenically unsaturated carboxylic acid or derivatives thereof includes maleic anhydride, (meth)acrylic acid, or derivatives thereof such as esters and nitrogen-containing monomers. Such nitrogen-containing monomers include an amino-hydrocarbyl morpholine (such as n-aminopropylmorpholine), an aminoalcohol, N,N-dimethyl acrylamide, a N-vinyl carbonamide (such as N-vinyl formamide, N-vinyl acetamide, N-vinyl propionamide, N-vinyl hydroxyacetamide), vinyl pyridine, N-vinyl imidazole, N-vinyl pyrrolidinone, N-vinyl caproplactam, a dialkylaminoalkyl (meth)acrylamide or dialkylaminoalkyl (meth)acrylate, a N-substituted alkanediamaine (such as N-methyl-1,3-propanediamine), or mixtures thereof.
[0035] The copolymer may be prepared as is described in International publication WO2010/014655 A. For example, the copolymer of the invention prepared by the reaction of monomers (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof are described in paragraph [0140] to [0141] of WO2010/014655 A. The copolymer may in one embodiment be a copolymer derived from 1-dodecene and maleic anhydride. Exemplified copolymers include those prepared below. The esterification and reaction of the acid monomer with an amine may occur prior to or after polymerization of the monomers; typically after polymerization.
[0036] Copolymer Backbone Preparation:
[0037] A copolymer may be prepared by reacting in a 3 litre flask 1 mole of maleic anhydride, and Y moles (defined below) of 1-dodecene in the presence of 60 wt % of toluene solvent. The flask is fitted with a flange lid and clip, PTFE stirrer gland, rod and overhead stirrer, thermocouple, nitrogen inlet port and water-cooled condenser. Nitrogen is blown through the flask at 0.028 m 3 /hr (or 1 SCFH). A separate 500 ml flask with a side arm is charged with 0.05 moles of tert-butyl peroxy-2-ethylhexanoate initiator (a commercially available initiator from Akzo Nobel, known as Trigonox®21S), optionally n-dodecyl mercaptan (chain transfer agent, CTA) and additional toluene. A nitrogen line is fitted to the arm and nitrogen is applied at 0.085 m 3 /hr (or 0.3 SCFH) for 30 minutes. The 3 litre flask is heated to 105° C. The Trigonox 21S initiator/toluene mixture is pumped from the 500 ml flask into the 3 litre flask via a Masterflex™ pump (flow rate set at 0.8 ml/min) over a period of 5 hours. The contents of the 3 litre flask are stirred for 1 hour before cooling to 95° C. The contents of the 3 litre flask are stirred overnight. Typically a clear colourless gel is obtained. The amount of each reagent is shown in the table below.
[0038] The copolymers prepared are characterised by RSV method described in the description above. The RSV data is presented in the table.
[0000]
Copolymer Prep
Y moles of
Mole Ratio of CTA
Example
1-Dodecene
to Initiator
RSV
Cpp1
1
0:1
0.058
Cpp2
0.95
0:1
0.071
[0039] The copolymer may optionally be prepared in the presence of a free radical initiator, solvent, chain transfer agent, or mixtures thereof. A person skilled in the art will appreciate that altering the amount of initiator and/or chain transfer agent will alter the number average molecular weight and RSV of the copolymer of the invention.
[0040] The solvent is known and is normally a liquid organic diluent. Generally, the solvent has as a boiling point thereof high enough to provide the required reaction temperature. Illustrative diluents include toluene, t-butyl benzene, benzene, xylene, chlorobenzene and various petroleum fractions boiling above 125° C.
[0041] The free radical initiator is known and includes peroxy compounds, peroxides, hydroperoxides, and azo compounds which decompose thermally to provide free radicals. Other suitable examples are described in J. Brandrup and E. Immergut, Editor, “Polymer Handbook”, 2nd edition, John Wiley and Sons, New York (1975), pages II-1 to II-40. Examples of a free radical initiator include those derived from a free radical-generating reagent, and examples include benzoyl peroxide, t-butyl perbenzoate, t-butyl metachloroperbenzoate, t-butyl peroxide, sec-butylperoxydicarbonate, azobisisobutyronitrile, t-butyl peroxide, t-butyl hydroperoxide, t-amyl peroxide, cumyl peroxide, t-butyl peroctoate, t-butyl-m-chloroperbenzoate, azobisisovaleronitrile or mixtures thereof. In one embodiment the free radical generating reagent is t-butyl peroxide, t-butyl hydroperoxide, t-amyl peroxide, cumyl peroxide, t-butyl peroctoate, t-butyl-m-chloroperbenzoate, azobisisovaleronitrile or mixtures thereof. Commercially available free radical initiators include classes of compound sold under the trademark Trigonox®-21 from Akzo Nobel.
[0042] The chain transfer agent is known to a person skilled in the art. The chain transfer agent may be added to a polymerisation as a means of controlling the molecular weight of the polymer. The chain transfer agent may include a sulphur-containing chain transfer agent such as n- and t-dodecyl mercaptan, 2-mercapto ethanol, methyl-3-mercaptopropionate. Terpenes can also be used. Typically the chain transfer agent may be n- and t-dodecyl mercaptan.
[0043] The esterified copolymer may be formed by reaction of carboxylic acid groups of the ethylenically unsaturated carboxylic acid or derivatives thereof. The alcohol may be a linear or branched alcohol, a cyclic or acyclic alcohol, or a combination of features thereof. The alcohol typically reacts with the ethylenically unsaturated carboxylic acid or derivatives thereof (before or after polymerization, typically after) to form esterified groups.
[0044] The esterified groups may be derivable from linear or branched alcohols. The alcohol may have 1 to 150, or 4 to 50, or 8 to 20 carbon atoms. Typically the number of carbon atoms is sufficient to make the copolymer of the invention dispersible or soluble in oil.
[0045] In different embodiments the alcohol may be a primary alcohol branched at the β- or higher position may have at least 12 (or at least 16, or at least 18 or at least 20) carbon atoms. The number of carbon atoms may range from at least 12 to 60, or at least 16 to 30.
[0046] The alcohol may be a fatty alcohol of various chain lengths (typically containing 6 to 20, or 8 to 18, or 10 to 15 carbon atoms). The fatty alcohol includes Oxo Alcohol® 7911, Oxo Alcohol® 7900 and Oxo Alcohol® 1100 of Monsanto; Alphanol® 79 of ICI; Nafol® 1620, Alfol® 610 and Alfol® 810 of Condea (now Sasol); Epal® 610 and Epal® 810 of Ethyl Corporation; Linevol® 79, Linevol® 911 and Dobanol® 25 L of Shell AG; Lial® 125 of Condea Augusta, Milan; Dehydad® and Lorol® of Henkel KGaA (now Cognis) as well as Linopol® 7-11 and Acropol® 91 of Ugine Kuhlmann.
[0047] The esterified groups may be derivable from Guerbet alcohols. Guerbet alcohols typically have one or more carbon chains with branching at the β- or higher position. The Guerbet alcohols may contain 10 to 60, or 12 to 60, or 16 to 40 carbon atoms. Methods to prepare Guerbet alcohols are disclosed in U.S. Pat. No. 4,767,815 (see column 5, line 39 to column 6, line 32).
[0048] The Guerbet alcohols may have alkyl groups including the following:
[0049] 1) alkyl groups containing C 15-16 polymethylene groups, such as 2-C 1-15 alkyl-hexadecyl groups (e.g. 2-octylhexadecyl) and 2-alkyl-octadecyl groups (e.g. 2-ethyloctadecyl, 2-tetradecyl-octadecyl and 2-hexadecyloctadecyl);
[0050] 2) alkyl groups containing C 13-14 polymethylene groups, such as 1-C 1-15 alkyl-tetradecyl groups (e.g. 2-hexyltetradecyl, 2-decyltetradecyl and 2-undecyltridecyl) and 2-C 1-15 alkyl-hexadecyl groups (e.g. 2-ethyl-hexadecyl and 2-dodecylhexadecyl);
[0051] 3) alkyl groups containing C 10-12 polymethylene groups, such as 2-C 1-15 alkyl-dodecyl groups (e.g. 2-octyldodecyl) and 2-C 1-15 alkyl-dodecyl groups (2-hexyldodecyl and 2-octyldodecyl), 2-C 1-15 alkyl-tetradecyl groups (e.g. 2-hexyltetradecyl and 2-decyltetradecyl);
[0052] 4) alkyl groups containing C 6-9 polymethylene groups, such as 2-C 1-15 alkyl-decyl groups (e.g. 2-octyldecyl) and 2,4-di-C 1-15 alkyl-decyl groups (e.g. 2-ethyl-4-butyl-decyl group);
[0053] 5) alkyl groups containing C 1-5 polymethylene groups, such as 2-(3-methylhexyl)-7-methyl-decyl and 2-(1,4,4-trimethylbutyl)-5,7,7-trimethyl-octyl groups; and
[0054] 6) and mixtures of two or more branched alkyl groups, such as alkyl residues of oxoalcohols corresponding to propylene oligomers (from hexamer to undecamer), ethylene/propylene (molar ratio 16:1-1:11) oligomers, iso-butene oligomers (from pentamer to octamer), C 5-17 α-olefin oligomers (from dimer to hexamer).
[0055] Typically the Guerbet alcohol has two alkyl groups with the difference in the number of carbon atoms between the two alkyl groups of 4 or less relative to the longer chain alkyl group.
[0056] Examples of suitable primary alcohol branched at the β- or higher position include 2-ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2-octyl-dodecanol, 2-decyltetradecanol, or mixtures thereof.
[0057] In one embodiment the alcohol comprises a mixture of (i) a Guerbet alcohol and (ii) a linear alcohol other than a Guerbet alcohol. The other alcohol may be a fatty alcohol described above.
[0058] The copolymer of the invention may be esterified in the presence of an alcohol described above. In one embodiment, the esterified copolymer may be further treated with an alcohol (such as a C1-C6 alcohol, typically butanol) to react with residual carboxylic acid groups of the copolymer, thus reducing the acid number to a desired value. The esterification reaction of the alcohol with the ethylenically unsaturated carboxylic acid or derivatives thereof is outlined below.
[0059] Esterified Copolymer:
[0060] The esterified copolymer may be prepared in a flask fitted with a Dean-Stark trap capped with a condenser. An amount of copolymer containing 1 mole of carboxy groups is heated in the flask to 110° C. and stirred for 30 minutes. One mole of alcohol is added. If the amount of the primary alcohol branched at the β- or higher position to be charged is greater than one mole, only one mole is added at this point. Conversely if less than one mole of the primary alcohol branched at the β- or higher position is intended, sufficient linear alcohol is used to provide a total of one mole equivalent of alcohol. The alcohol is pumped into the flask via peristaltic pump over a period of 35 minutes. Catalytic amounts of methane sulphonic acid along with the remaining moles of alcohol are then pumped into the flask over a period of 5 hours whilst heating to and holding at 145° C. and removing water in the Dean-Stark trap.
[0061] The reaction temperature is reduced to 135° C., and sufficient butanol is added sequentially to the flask until the total acid number (TAN) is not higher than 4 mg KOH/g. The flask is heated to 150° C. and sufficient sodium hydroxide is added to quench the methanesulphonic acid. The flask is cooled to ambient temperature resulting in an esterified copolymer. Optionally, the product is vacuum stripped to remove any volatile materials such as water or alcohol.
[0062] The procedure may employ the materials listed in the table below.
[0000] Moles of Branched Ester Copolymer Moles of Linear Alcohol Copolymer Prep Alcohol B1 B2 B3 Esc1 Cpp1 2.0 Esc2 Cpp1 1 1 Esc3 Cpp1 1 1 Esc4 Cpp1 1 1 Esc5 Cpp1 1.8 0.2 Esc6 Cpp1 1.8 0.2 Esc7 Cpp1 1.8 0.2 Esc8 Cpp1 0.5 1.5 Esc9 Cpp1 0.5 1.5 Esc10 Cpp1 0.5 1.5 Esc11 Cpp1 2 Esc12 Cpp1 2 Esc13 Cpp1 2 Footnote: The linear alcohol is a C 8-10 mixture commercially available as Alfol ®810. Minor amounts of butanol are not included in the reported amounts. B1 is 2-hexyldecanol. B2 is 2-ethylhexanol. B3 is a 2-octyldodecanol.
Moles of alcohol referred to in the table relate to the total number of moles of alcohol relative to the total number carboxyl groups of the unsaturated carboxylic acid of the copolymer. Typically 2 moles of alcohol react with two moles of carboxyl groups derived from maleic anhydride.
[0063] The esterified copolymer may be further reacted with an amine. The amine may include any amine capable of providing, when incorporated onto the copolymer, a TBN (i.e., a total base number) of greater than 0 mg KOH/g, or 1 to 20 mg KOH/g, or 2 to 12 mg KOH/g).
[0064] Examples of the amine include an amino-hydrocarbyl morpholine (such as n-aminopropylmorpholinc), an aminoalcohol, N,N-dimethylacrylamide, a N-vinyl carbonamide (such as, N-vinyl-formamide, N-vinylacetoamide, N-vinyl propionamide, N-vinyl hydroxyacetoamide, vinyl pyridine, N-vinyl imidazole, N-vinyl pyrrolidinone, N-vinyl caprolactam, a dialkylaminoalkyl (meth)acrylamide or dialkylaminoalkyl (meth)acrylate, a N-substituted alkanediamine (such as d N-Methyl-1,3-propanediamine), or mixtures thereof.
[0065] Examples of the amine include an amino-hydrocarbyl morpholine (such as 3-morpholinopropylamine), an amino alcohol, an N-substituted alkanediamine (such as N,N-dimethyl-1,3-propanediamine), or mixtures thereof. In one embodiment the amine may be N,N-dimethyl-1,3-propanediamine
[0066] In one embodiment the amine may be an amino-hydrocarbyl morpholine (such as 3-morpholinopropylamine), an aminoalcohol or mixtures thereof.
[0067] The aminoalcohol may include a monoalkanolamine, a dialkanolamine, a trialkanolamine or mixtures thereof. Examples of the aminoalcohol include dimethylethanolamine, ethanolamine, isopropanolamine, diethanolamine, triethanolamine, N,N-diethylethanolamine, N,N-dimethylethanolamine, N,N-dibutylethanolamine, 3-amino-1,2-propanediol, serinol, 2-amino-2-methyl-1,3-propanediol, tris(hydroxymethyl)-aminomethane, diisopropanolamine, N-methyldiethanolamine, 3-(dimethylamino)-2,2-dimethylpropan-1-ol, and 2-(2-aminoethylamino)ethanol.
[0068] When an amine such as an amino-hydrocarbyl morpholine or another non-hydroxy containing amine is used, the primary amino group tends to form an imide with the ethylenically unsaturated carboxylic acid or derivatives thereof. In addition, the phosphate salt tends to form by subsequent reaction of the acid phosphate with the tertiary amine. For example the phosphate salt tends to form by reaction with the tertiary amino group of amino-hydrocarbyl morpholine, or with the tertiary amino group of N,N-dialkyl hydrocarbyl (eg N,N-dimethylaminopropylamine reaction products).
[0069] In one embodiment the amine may be amino-hydrocarbyl morpholine, an aminoalcohol, or mixtures thereof.
[0070] When an amine such as an aminoalcohol is used, the alcohol group tends to form (i) an ester with the units derived from the ethylenically unsaturated carboxylic acid or derivatives thereof if the amino group is tertiary; and (ii) an ester or amide with the units derived from the ethylenically unsaturated carboxylic acid or derivatives thereof if the amino group is primary or secondary. In addition, the phosphate salt tends to form by subsequent reaction of the phosphate with the amino group.
[0071] The amine may also include an alkylene polyamine, or mixtures thereof. The alkylene polyamine may be an ethylene polyamine, propylene polyamine, butylene polyamine, or mixtures thereof. Typically the polyamine may be an ethylene polyamine, or mixtures thereof. Ethylene polyamines, such as some of those mentioned above, are preferred. They are described in detail under the heading “Diamines and Higher Amines” in Kirk Othmer's “Encyclopedia of Chemical Technology”, 4th Edition, Vol. 8, pages 74-108, John Wiley and Sons, N.Y. (1993) and in Meinhardt, et al, U.S. Pat. No. 4,234,435.
[0072] Examples of ethylene polyamine include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, N-(2-amino ethyl)-N′-[2-[(2-aminoethyl)amino]ethyl]-1,2-ethanediamine, alkylene polyamine still bottoms, or mixtures thereof.
[0073] The alkylene polyamine bottoms may be characterized as having less than 2%, usually less than 1% (by weight) material boiling below about 200° C. In the instance of ethylene polyamine bottoms, which are readily available and found to be quite useful, the bottoms contain less than about 2% (by weight) total diethylene triamine (DETA) or triethylene tetramine (TETA). A typical sample of such ethylene polyamine bottoms obtained from the Dow Chemical Company of Freeport, Tex., designated “E-100” has a specific gravity at 15.6° C. of 1.0168, a percent nitrogen by weight of 33.15 and a viscosity at 40° C. of 121 cSt (mm 2 /s). Gas chromatography analysis of such a sample showed it contains about 0.93% “Light Ends” (most probably diethylenetriamine), 0.72% triethylenetetramine, 21.74% tetraethyl ene pentamine and 76.61% pentaethylene hexamine and higher (by weight). A similar alkylene polyamine bottoms are commercially sold under as E100™ polyethyleneamines from Dow Chemical.
[0074] The copolymer of the invention may be reacted with an amine as is shown below.
[0075] Preparative Example of an Esterified Copolymer Capped with an Amine (Ecca):
[0076] Each esterified copolymer from above is reacted with an amine in a flask fitted with a Dean-Stark trap capped with a condenser. Sufficient amine is added to provide the esterified copolymer with a weight percent nitrogen content as is shown in the table below. The amine is charged into the flask over a period of 30 minutes and stirred for 2-5 hours at 150° C. The flask is cooled to 115° C. and drained. The resultant product is vacuum stripped at 100-150° C. and held for 1.5-2.5 hours. The procedure employs the materials listed in the table below. The table below presents the information for a representative number of esterified copolymers capped with an amine.
[0000]
Esterified
Nitrogen Content
Ecca
Copolymer
Amine
(wt %)
Ecca1
Esc1
Amine 1
0.1
Ecca2
Esc2
Amine 1
0.25
Ecca3
Esc3
Amine 1
0.25
Ecca4
Esc3
Amine 1
0.4
Ecca5
Esc5
Amine 2
0.1
Ecca6
Esc5
Amine 2
0.25
Ecca7
Esc5
Amine 2
0.4
Ecca8
Esc1
Amine 2
0.1
Ecca9
Esc7
Amine 2
0.1
Ecca10
Esc9
Amine 2
0.25
Ecca11
Esc9
Amine 3
0.15
Ecca12
Esc5
Amine 3
0.375
Ecca13
Esc12
Amine 3
0.6
Ecca14
Esc5
Amine 1
0.1
Ecca15
Esc5
Amine 1
0.25
Footnote:
Amine 1 is 4-(3-aminopropyl)morpholine
Amine 2 is 3-(dimethylamino)-1-propylamine
Amine 3 is 1-(3-aminopropyl) imidazole
[0077] The phosphate salt may be derivable from reacting an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers: (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof, that are esterified with an alcohol, or mixtures thereof, and wherein at least a portion of carboxylic acid groups not esterified react with an amine (typically having TBN of greater than 0 mg KOH/g, or 1 to 20 mg KOH/g, or 2 to 12 mg KOH/g) with a (thio)phosphorylating agent.
[0078] In one embodiment the copolymer of the invention comprises (i) the α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof (typically maleic anhydride), and (iii) one or more additional co-monomers that are known to copolymerize with the preceding monomers. Suitable co-monomers include vinyl aromatic monomers; alkyl meth(acrylates); vinyl acetate; and fumaric acid and derivatives thereof. The vinyl aromatic monomers include styrene or alkylstyrene (such as alpha-methylstyrene, para-tert-butylstyrene, alpha-ethylstyrene, and para-lower alkoxy styrene), or mixtures thereof. In one embodiment the vinyl aromatic monomer may be styrene.
(Thio)Phosphating Agent
[0079] As used herein, the expression “(thio)phosphorylating agent” is meant to include a phosphorylating agent, a thiophosphorylating agent, or mixtures thereof. In one embodiment the phosphorylating agent does not contain sulphur. As used herein the expression “(thio)phosphorylating agent” may be used interchangeably with the expression “(thio)phosphating agent”.
[0080] The (thio)phosphorylating agent which may be employed is typically phosphorus pentoxide, phosphorus pentasulphide, or reactive equivalents thereof. Reactive equivalents of thiophosphoric acid or phosphoric acid include acid halides, esters, amides, anhydrides, salts, partial salts, or mixtures thereof. The (thio)phosphorylating agent may have phosphorus in its +5 oxidation state.
[0081] Phosphorus pentoxide is usually referred to as P 2 O 5 , which is its empirical formula, and phosphorus pentasulphide is usually referred to as P 2 S 5 , which is its empirical formula, even though it is believed that both molecules consist at least in part of more complex molecules such as P 4 O 10 , or P 4 S 10 . The (thio)phosphorylating agent may include POCl 3 , P 2 O 5 , P 4 O 10 , polyphosphoric acid, P 2 S 5 , or P 4 S 10 , or mixtures thereof. In one embodiment the (thio)phosphorylating agent may be a sulphur-free phosphating agent, typically POCl 3 , P 2 O 5 , P 4 O 10 , or polyphosphoric acid.
[0082] The (thio)phosphate salt of the amine-functionalized copolymer, may also be a product obtained/obtainable by reacting: (i) a hydroxy-containing carboxylic compound (such as a hydroxy-containing carboxylic acid), or derivatives thereof (the derivative may include ester, amide, or partial salts of amide or ester, (typically partial ester), or a compound may be derived from a partially esterified polyol (such as glycerol)) and/or an alcohol (typically a monohydric alcohol, or a dihydric alcohol), a (thio)phosphorylating agent, and esterified ester copolymer capped with an amine. The resultant product may be referred to as an acid (thio)phosphate.
[0083] As used herein the expression “acid (thio)phosphate” is known to a person skilled in the art to include an acid thiophosphate or an acid phosphate (free of sulphur).
[0084] The acid (thio)phosphate which may be a product obtained/obtainable by reacting: a hydroxy-containing carboxylic compound, and/or an alcohol (typically a monohydric alcohol or a dihydric alcohol), a (thio)phosphorylating agent, and capped with amine having a basic nitrogen. The amine having a basic nitrogen when incorporated into the product may have a total base number (TBN) of greater than 0 mg KOH/g, or 1 to 20 mg KOH/g, or 2 to 12 mg KOH/g.
[0085] In one embodiment the (thio)phosphate salt may be an acid (thio)phosphate which may be a product obtained/obtainable by reacting: (i) a hydroxy-containing carboxylic acid, or derivatives thereof and a (thio)phosphorylating agent, and capped with amine having a basic nitrogen.
[0086] In one embodiment the (thio)phosphate salt may be an acid (thio)phosphate which may be a product obtained/obtainable by reacting: (i) an alcohol (typically a monohydric alcohol or a dihydric alcohol) and a (thio)phosphorylating agent, and capped with amine having a basic nitrogen.
[0087] The (thio)phosphorylating agent may be mixed with and reacted with the hydroxy-containing carboxylic compound, and or alcohol in any order.
[0088] The (thio)phosphorylating agent itself may also be introduced into the reaction mixture in a single portion, or it may be introduced in multiple portions. Thus, in one embodiment an acid (thio)phosphate product (or intermediate) is prepared wherein a portion of the (thio)phosphorylating agent is reacted the hydroxy-containing carboxylic compound, and/or the alcohol and thereafter a second charge of the (thio)phosphating agent is added.
[0089] In one embodiment the (thio)phosphate salt of an amine-functionalized copolymer may be obtained/obtainable by reacting the product of (i) with esterified ester copolymer capped with amine having basic nitrogen. The product may be a polymer bound alkylammonium salt of a (thio)phosphate ester of the hydroxy-containing carboxylic compound, typically a (thio)phosphate ester derivative. For example the product may be an alkyl hydroxy-carboxylate (thio)phosphate polymer bound trialkyl ammonium salt, or mixtures thereof. The trialkyl ammonium salt may be derived from an amine having a tertiary amino group as described below.
[0090] In one embodiment the present invention provides a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized copolymer obtained/obtainable by reacting: (i) an alcohol (typically a monohydric alcohol or a dihydric alcohol), or derivatives thereof, a (thio)phosphorylating agent, and in the absence of a hydroxy-containing carboxylic compound (typically a hydroxy-containing carboxylic acid), and optionally (ii) reacting the product of (i) with an esterified ester copolymer capped with an amine having a basic nitrogen.
[0091] In one embodiment the present invention provides a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized copolymer obtained/obtainable by reacting: (i) a hydroxy-containing carboxylic compound (typically a hydroxy-containing carboxylic acid, or derivatives thereof), a (thio)phosphorylating agent, and an alcohol (typically a monohydric alcohol, or a dihydric alcohol), and optionally (ii) reacting the product of (i) with an amine, or mixtures thereof. In one embodiment the invention provides a lubricating composition, wherein the product of (i) is further reacted with an amine, or mixtures thereof.
[0092] In one embodiment the present invention provides a lubricating composition comprising an oil of lubricating viscosity and a (thio)phosphate salt of an amine-functionalized esterified copolymer, wherein the esterified copolymer comprises units derived from monomers: (i) an α-olefin and (ii) an ethylenically unsaturated carboxylic acid or derivatives thereof (typically carboxylic acid groups or an anhydride), that are esterified with an alcohol, or mixtures thereof, and wherein at least a portion of carboxylic acid groups not esterified react with an amine, wherein the (thio)phosphate salt is obtained/obtainable by reacting: a hydroxy-containing carboxylic compound (typically a hydroxy-containing carboxylic acid, or derivatives thereof), a (typically sulphur-free) phosphating agent, and optionally an alcohol.
[0093] The resultant product may then be reacted with the amine of the esterified copolymer described herein.
[0094] In one embodiment the hydroxy-containing carboxylic compound may be a hydroxy-carboxylic acid, or derivatives thereof, a partially esterified polyol, or mixtures thereof.
[0095] The hydroxy-containing carboxylic compound may include a compound derived from a hydroxy-containing carboxylic acid represented by the formulae:
[0000]
[0000] wherein
n and m may be independently integers of 1 to 5;
X may be an aliphatic or alicyclic group, or an aliphatic or alicyclic group containing an oxygen atom in the carbon chain, or a substituted group of the foregoing types, said group containing up to 6 carbon atoms and having n+m available points of attachment;
each Y may be independently —O—, >NH, or >NR 1 or two Ys together representing the nitrogen of an imide structure R—N< formed between two carbonyl groups; and
each R and R 1 may be independently hydrogen or a hydrocarbyl group, provided that at least one R or R 1 group is a hydrocarbyl group; each R 2 may be independently hydrogen, a hydrocarbyl group or an acyl group, further provided that at least one —OR 2 group is located on a carbon atom within X that is α or β to at least one of the —C(O)—Y—R groups, with the proviso that at least one R 2 group is hydrogen.
[0096] The compound derived from the hydroxy-carboxylic compound may be derived from glycolic acid (n and m both equal 1), malic acid (n=2, m=1), tartaric acid (n and m both equal 2), citric acid (n=3, m=1), or mixtures thereof. In one embodiment the compound derived from the hydroxy-carboxylic compound may be derived from tartaric acid or glycolic acid, typically tartaric acid.
[0097] The compound (II) derived from the hydroxy-containing carboxylic acid may be derived from a partially esterified polyol (such as glycerol), or mixtures thereof. The partially esterified polyol may be glycerol monooleate, or glycerol dioleate.
[0098] The alcohol is reacted with the (thio)phosphating agent. The alcohol includes the monohydric alcohol, or the dihydric alcohol. The carbon atoms of the alcohol may be in linear chains, branched chains, or mixtures thereof. When branched, the alcohol may be a Guerbet alcohol, or mixtures thereof. A branched alcohol may contain 6 to 40 or 6 to 30, or 8 to 20 carbon atoms (typically 8 to 20 carbon atoms).
[0099] The Guerbet alcohols have been described previously.
[0100] Examples of a suitable branched alcohol include 2-ethylhexanol, 2-butyloctanol, 2-hexyldecanol, 2-octyldodecanol, 2-decyltetradecanol, iso-tridecanol, iso-octyl, Guerbet alcohols, or mixtures thereof.
[0101] Examples of a monohydric alcohol include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol, octadecanol, nonadecanol, eicosanol, or mixtures thereof. In one embodiment the monohydric alcohol contains 6 to 30, or 8 to 20, or 8 to 15 carbon atoms (typically 8 to 15 carbon atoms).
[0102] The alcohol may include commercially available materials such as Oxo Alcohol® 7911, Oxo Alcohol® 7900 and Oxo Alcohol® 1100 of Monsanto; Alphanol® 79 of ICI; Nafol® 1620, Alfol® 610 and Alfol® 810 of Condea (now Sasol); Epal® 610 and Epal® 810 of Ethyl Corporation (now Afton); Linevol® 79, Linevol® 911 and Dobanol® 25 L of Shell AG; Lial® 125 of Condea Augusta, Milan; Dehydad® and Lorol® of Henkel KGaA (now Cognis) as well as Linopol® 7-11 and Acropol® 91 of Ugine Kuhlmann.
[0103] The dihydric alcohol may include an alkylene diol, or mixtures thereof. The alkane diol may be in a 1,2- or 1,3- or 1,4-arrangement. For example alkane diol hydroxyl groups may be attached to adjacent carbon atoms (i.e., 1,2- or a vicinal diol).
[0104] Examples of the alkylene diol include ethylene glycol, 1,2-propylene glycol, 1,2-butylene glycol; also 1,3-propylene diol, 1,3-butylene diol, 1,4-butylene diol, 1,2-hexylene diol, 1,2-dodecylene diol, and 1,2-octadecylene diol.
[0105] In one embodiment the hydroxy-containing carboxylic acid and/or the alcohol, or derivatives thereof, the (thio)phosphorylating agent may be reacted at a temperature in the range of 30° C. to 100° C., or 50° C. to 90° C. The reaction may form a mono- or di-phosphate ester.
[0106] The reaction of the esterified copolymer and an amine in step (ii) may be carried out at a temperature in the range of 30° C. to 120° C., or 40° C. to 90° C.
[0107] In one embodiment the hydroxy-containing carboxylic acid and/or the alcohol, or derivatives thereof, the (thio)phosphorylating agent may be reacted at a temperature in the range of 30° C. to 100° C., or 50° C. to 90° C. in the presence of the esterified copolymer amine. The reaction may form a mono- or di-phosphate ester.
[0108] The relative amounts of the hydroxy-containing carboxylic acid, or derivatives thereof to the alcohol may be 1:0 to 0:1, or 0.8:0.2 to 0.2:0.8. At a 1:1 mole ratio of the hydroxy-containing carboxylic acid, or derivatives thereof having 2 or more hydroxyl groups to the alcohol (typically a monohydric alcohol, or a dihydric alcohol), the mole ratio of hydroxyl groups will be >1:1.
[0109] The hydroxy-containing carboxylic acid, or derivatives thereof (and optionally the monohydric alcohol or dihydric alcohol) are reacted with the (thio)phosphorylating agent in such overall amounts that the product mixture formed thereby contains (thio)phosphorus acid functionality. That is, the (thio)phosphorylating agent is not completely converted to its ester form but will retain at least a portion of P—OH, or P—SH acidic functionality, which is accomplished by using a sufficient amount of the (thio)phosphorylating agent compared with the equivalent amounts of the hydroxy-containing carboxylic acid, or derivatives thereof (and optionally the alcohol). In particular, in certain embodiments the (thio)phosphorylating agent (which may comprise phosphorus pentoxide), may be reacted with the hydroxy-containing carboxylic acid, or derivatives thereof (and optionally the alcohol) in a ratio of 1:2.5 moles (or 1.25:2 moles) of hydroxyl groups per 1 mole of phosphorus from the (thio)phosphorylating agent.
[0110] In one somewhat oversimplified schematic representation using P 2 O 5 for illustrative purposes, the reaction of the phosphating agent with alcohol(s) may be represented as follows:
[0000] 3ROH+P 2 O 5 →(RO) 2 P(═O)OH+RO—P(═O)(OH) 2
[0000] where ROH represent hydroxyl groups of either (i) a hydroxy-containing carboxylic compound, or derivatives thereof, (ii) a monoalcohol, (iii) a mixture of a monool and diol, or (iv) a mixture of the hydroxy-containing carboxylic acid, or derivatives thereof with an alcohol (typically a monohydric alcohol, or a dihydric alcohol). As will be seen below, the residual phosphoric acidic functionality may be reacted at least in part with an amine.
[0111] The amine may be reacted with the copolymer described above. The incorporated amine having basic nitrogen may contain a secondary or tertiary amino group (typically a tertiary amino group). The incorporated amine may for instance include dimethylaminopropylamine, N,N-dimethyl-aminopropylamine, N,N-diethyl-aminopropylamine, N,N-dimethyl-aminoethylamine, ethylenediamine, 1,2-propylenediamine, 1,3-propylene diamine, the isomeric butylenediamines, pentanediamines, hexanediamines, heptanediamines, diethylenetriamine, dipropylenetriamine, dibutylenetriamine, triethylenetetraamine, tetraethylenepentaamine, pentaethylenehexaamine, hexamethyleneheptaamine, and bis(hexamethylene)triamine, 3,3-diamino-N-methyldipropylamine, or 3′3-aminobis(N,N-dimethylpropylamine) or mixtures thereof.
[0112] The amine having basic nitrogen may in one embodiment be dimethylaminopropylamine, N,N-dimethyl-aminopropylamine, N,N-diethyl-aminopropylamine, N,N-dimethyl-aminoethylamine ethylenediamine, 1,2-propylenediamine, or mixtures thereof.
[0113] The amine having basic nitrogen may be substituted heterocyclic compounds such as 1-(3-aminopropyl)imidazole, 4-(3-aminopropyl)morpholine, 1-(2-amino ethyl)piperidine, 1-(3-aminopropyl)-2-pipecoline, 1-methyl-(4-methylamino)piperidine, 4-(1-pyrrolidinyl)piperidine, 1-(2-aminoethyl)-pyrrolidine, 2-(2-aminoethyl)-1-methylpyrrolidine, or mixtures thereof.
[0114] The amine having basic nitrogen may optionally include oxygen. The amine of this type may include an alkanolamine such as N,N-dimethylaminopropanol, N,N-diethylaminopropanol, N,N-diethylaminobutanol, or mixtures thereof.
[0115] The amine having basic nitrogen may also include amines having (a tertiary amino group. Amines of this type include N,N-diethylethylenediamine, N,N-dimethylethylenediamine, N,N-dibutylethylenediamine, N,N-diethyl-1,3-diaminopropane, N,N-dimethyl-1,3-diaminopropane, N,N,N′-trimethylethylenediamine, N,N-dimethyl-N′-ethylethylenediamine, N,N-diethyl-N′-methylethylenediamine, N,N,N′-triethylethylenediamine, 3-dimethylaminopropylamine, 3-diethylaminopropylamine, 3-dibutylaminopropylamine, N,N,N′-trimethyl-1,3-propanediamine,N,N,2,2-tetramethyl-1,3-propanediamine, 2-amino-5-diethylaminopentane, N,N,N′,N′-tetraethyldiethylenetriamine, 3,3′-diamino-N-methyldipropylamine, 3,3′-iminobis(N,N-dimethylpropylamine), or mixtures thereof. In one particular embodiment the amine having basic nitrogen may be N,N-dimethyl-1,3-diaminopropane, N,N-diethyl-1,3-diaminopropane, N,N-dimethylethylenediamine, N,N-diethylethylenediamine, N,N-dibutylethylenediamine, or mixtures thereof.
Oils of Lubricating Viscosity
[0116] The lubricating composition comprises an oil of lubricating viscosity. Such oils include natural and synthetic oils, oil derived from hydrocracking, hydrogenation, and hydrofinishing, unrefined, refined, re-refined oils or mixtures thereof. A more detailed description of unrefined, refined and re-refined oils is provided in International Publication WO2008/147704, paragraphs [0054] to [0056] (a similar disclosure is provided in US Patent Application 2010/197536, see [0072] to [0073]). A more detailed description of natural and synthetic lubricating oils is described in paragraphs [0058] to [0059] respectively of WO2008/147704 (a similar disclosure is provided in US Patent Application 2010/197536, see [0075] to [0076]). Synthetic oils may also be produced by Fischer-Tropsch reactions and typically may be hydroisomerised Fischer-Tropsch hydrocarbons or waxes. In one embodiment oils may be prepared by a Fischer-Tropsch gas-to-liquid synthetic procedure as well as other gas-to-liquid oils.
[0117] Oils of lubricating viscosity may also be defined as specified in April 2008 version of “Appendix E—API Base Oil Interchangeability Guidelines for Passenger Car Motor Oils and Diesel Engine Oils”, section 1.3 Sub-heading 1.3. “Base Stock Categories”. The API Guidelines are also summarised in U.S. Pat. No. 7,285,516 (see column 11, line 64 to column 12, line 10). In one embodiment the oil of lubricating viscosity may be an API Group II, Group III, Group IV oil, or mixtures thereof.
[0118] The amount of the oil of lubricating viscosity present is typically the balance remaining after subtracting from 100 wt % the sum of the amount of the copolymer of the invention and the other performance additives.
[0119] The lubricating composition may be in the form of a concentrate and/or a fully formulated lubricant. If the copolymer of the present invention is in the form of a concentrate (which may be combined with additional oil to form, in whole or in part, a finished lubricant), the ratio of the of components the copolymer of the present invention to the oil of lubricating viscosity and/or to diluent oil include the ranges of 1:99 to 99:1 by weight, or 80:20 to 10:90 by weight.
Other Performance Additives
[0120] Compositions derived from the copolymer and/or lubricating compositions described herein optionally further includes other performance additives. The other performance additives comprise at least one of metal deactivators, detergents, dispersants, viscosity modifiers (other than the copolymer of the present invention), friction modifiers, corrosion inhibitors, dispersant viscosity modifiers (other than the copolymer of the present invention), antiwear agents (other than the copolymer of the present invention), extreme pressure agents (other than the copolymer of the present invention), antiscuffing agents, antioxidants, foam inhibitors, demulsifiers, pour point depressants, seal swelling agents and mixtures thereof. Typically, fully-formulated lubricating oil will contain one or more of these performance additives.
Dispersants
[0121] Dispersants are often known as ashless-type dispersants because, prior to mixing in a lubricating oil composition, they do not contain ash-forming metals and they do not normally contribute any ash forming metals when added to a lubricant and polymeric dispersants. Ashless type dispersants are characterised by a polar group attached to a relatively high molecular weight hydrocarbon chain. Typical ashless dispersants include N-substituted long chain alkenyl succinimides. Examples of N-substituted long chain alkenyl succinimides include polyisobutylene succinimide with number average molecular weight of the polyisobutylene from which it is derived in the range 350 to 5000, or 500 to 3000.
[0122] In one embodiment the invention further includes at least one dispersant derived from polyisobutylene, an amine and zinc oxide to form a polyisobutylene succinimide complex with zinc. The polyisobutylene succinimide complex with zinc may be used alone or in combination.
[0123] Another class of ashless dispersant is Mannich bases. Mannich dispersants are the reaction products of alkyl phenols with aldehydes (especially formaldehyde) and amines (especially polyalkylene polyamines). The alkyl group typically contains at least 30 carbon atoms.
[0124] The dispersants may also be post-treated by conventional methods by a reaction with any of a variety of agents. Among these are boron compounds (such as boric acid), urea, thiourea, dimercaptothiadiazoles, carbon disulphide, aldehydes, ketones, carboxylic acids such as terephthalic acid, hydrocarbon-substituted succinic anhydrides, maleic anhydride, nitrites, epoxides, and phosphorus compounds. In one embodiment the post-treated dispersant is borated.
[0125] In one embodiment the dispersant may be a post treated dispersant. The dispersant may be post treated with dimercaptothiadiazole, optionally in the presence of one or more of a phosphorus compound, a dicarboxylic acid of an aromatic compound, and a borating agent.
[0126] In one embodiment the post treated dispersant may be formed by heating an alkenyl succinimide or succinimide detergent with a phosphorus ester and water to partially hydrolyze the ester. The post treated dispersant of this type is disclosed for example in U.S. Pat. No. 5,164,103.
[0127] In one embodiment the post treated dispersant may be produced by preparing a mixture of a dispersant and a dimercaptothiadiazole and heating the mixture above about 100° C. The post treated dispersant of this type is disclosed for example in U.S. Pat. No. 4,136,043.
[0128] In one embodiment the dispersant may be post treated to form a product prepared comprising heating together: (i) a dispersant (typically a succinimide), (ii) 2,5-dimercapto-1,3,4-thiadiazole or a hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole, or oligomers thereof, (iii) a borating agent (similar to those described above); and (iv) optionally a dicarboxylic acid of an aromatic compound selected from the group consisting of 1,3 diacids and 1,4 diacids (typically terephthalic acid), or (v) optionally a phosphorus acid compound (including either phosphoric acid or phosphorous acid), said heating being sufficient to provide a product of (i), (ii), (iii) and optionally (iv) or optionally (v), which is soluble in an oil of lubricating viscosity. The post treated dispersant of this type is disclosed for example in International Application WO 2006/654726 A.
[0129] Examples of a suitable dimercaptothiadiazole include 2,5-dimercapto-1,3,4-thiadiazole or a hydrocarbyl-substituted 2,5-dimercapto-1,3,4-thiadiazole. In several embodiments the number of carbon atoms on the hydrocarbyl-substituent group includes 1 to 30, 2 to 25, 4 to 20, or 6 to 16. Examples of suitable 2,5-bis(alkyl-dithio)-1,3,4-thiadiazoles include 2,5-bis(tert-octyldithio)-1,3,4-thiadiazole 2,5-bis(tert-nonyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-decyl-dithio)-1,3,4-thiadiazole, 2,5-bis(tert-undecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-dodecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-tridecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-tetradecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-pentadecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-hexadecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-heptadecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-octadecyldithio)-1,3,4-thiadiazole, 2,5-bis(tert-nonadecyldithio)-1,3,4-thiadiazole or 2,5-bis(tert-eicosyldithio)-1,3,4-thiadiazole, or oligomers thereof.
Detergents
[0130] The lubricant composition optionally further includes known neutral or overbased detergents, i.e., ones prepared by conventional processes known in the art. Suitable detergent substrates include, phenates, sulphur containing phenates, sulphonates, salixarates, salicylates, carboxylic acid, phosphorus acid, alkyl phenol, sulphur coupled alkyl phenol compounds, or saligenins.
Antioxidant
[0131] Antioxidant compounds are known and include sulphurised olefins, diarylamine alkylated diarylamines, hindered phenols, molybdenum dithiocarbamates, and mixtures thereof. Antioxidant compounds may be used alone or in combination.
[0132] The hindered phenol antioxidant often contains a secondary butyl and/or a tertiary butyl group as a sterically hindering group. The phenol group is often further substituted with a hydrocarbyl group and/or a bridging group linking to a second aromatic group. Examples of suitable hindered phenol antioxidants include 2,6-di-tert-butylphenol, 4-methyl-2,6-di-tert-butylphenol, 4-ethyl-2,6-di-tert-butylphenol, 4-propyl-2,6-di-tert-butylphenol or 4-butyl-2,6-di-tert-butylphenol, or 4-dodecyl-2,6-di-tert-butylphenol. In one embodiment the hindered phenol antioxidant is an ester and may include, e.g., Irganox™ L-135 from Ciba. Suitable examples of molybdenum dithiocarbamates which may be used as an antioxidant include commercial materials sold under the trade names such as Vanlube 822™ and Molyvan™ A from R. T. Vanderbilt Co., Ltd., and Adeka Sakura-Lube™ S-100, S-165 and S-600 from Asahi Denka Kogyo K. K and mixtures thereof.
[0133] The diarylamine alkylated diarylamine may be a phenyl-α-naphthylamine (PANA), an alkylated diphenylamine, or an alkylated phenylnapthylamine, or mixtures thereof. The alkylated diphenylamine may include di-nonylated diphenylamine, nonyl diphenylamine, octyl diphenylamine, di-octylated diphenylamine, di-decylated diphenylamine, decyl diphenylamine and mixtures thereof. In one embodiment the diphenylamine may include nonyl diphenylamine, dinonyl diphenylamine, octyl diphenylamine, dioctyl diphenylamine, or mixtures thereof. In one embodiment the diphenylamine may include nonyl diphenylamine, or dinonyl diphenylamine. The alkylated diarylamine may include octyl, di-octyl, nonyl, di-nonyl, decyl or di-decyl phenylnapthylamines.
Viscosity Modifiers
[0134] The lubricating composition optionally further includes at least one viscosity modifier other than the product of the present invention. The viscosity modifier may include hydrogenated styrene-butadiene rubbers, ethylene-propylene copolymers, hydrogenated styrene-isoprene polymers, hydrogenated diene polymers, polyalkyl styrenes, polyolefins, polyalkyl (meth)acrylates, esters of maleic anhydride-styrene copolymers, or mixtures thereof. In one embodiment the polymeric viscosity modifier may be a poly(meth)acrylate, or mixtures thereof.
Antiwear Agent
[0135] The lubricating composition optionally further includes at least one antiwear agent other than the product of the present invention. Examples of suitable antiwear agents include oil soluble amine salts of phosphorus compounds, sulphurised olefins, metal dihydrocarbyldithiophosphates (such as zinc dialkyldithiophosphates), thiocarbamate-containing compounds, such as thiocarbamate esters, thiocarbamate amides, thiocarbamic ethers, alkylene-coupled thiocarbamates, and bis(S-alkyldithiocarbamyl)disulphides.
[0136] In one embodiment the oil soluble phosphorus amine salt antiwear agent includes an amine salt of a phosphorus acid ester or mixtures thereof. The amine salt of a phosphorus acid ester includes phosphoric acid esters and amine salts thereof; dialkyldithiophosphoric acid esters and amine salts thereof; amine salts of phosphites; and amine salts of phosphorus-containing carboxylic esters, ethers, and amides; and mixtures thereof. The amine salt of a phosphorus acid ester may be used alone or in combination.
[0137] In one embodiment the oil soluble phosphorus amine salt includes partial amine salt-partial metal salt compounds or mixtures thereof. In one embodiment the phosphorus compound further includes a sulphur atom in the molecule. In one embodiment the amine salt of the phosphorus compound is ashless, i.e., metal-free (prior to being mixed with other components).
[0138] The amines which may be suitable for use as the amine salt include primary amines, secondary amines, tertiary amines, and mixtures thereof. The amines include those with at least one hydrocarbyl group, or, in certain embodiments, two or three hydrocarbyl groups. The hydrocarbyl groups may contain 2 to 30 carbon atoms, or in other embodiments 8 to 26, or 10 to 20, or 13 to 19 carbon atoms.
[0139] Primary amines include ethylamine, propylamine, butylamine, 2-ethylhexylamine, octylamine, and dodecylamine, as well as such fatty amines as n-octylamine, n-decyl amine, n-dodecyl amine, n-tetradecylamine, n-hex adecyl-amine, n-octadecylamine and oleyamine. Other useful fatty amines include commercially available fatty amines such as “Armeen®” amines (products available from Akzo Chemicals, Chicago, Ill.), such as Armeen C, Armeen O, Armeen OL, Armeen T, Armeen HT, Armeen S and Armeen SD, wherein the letter designation relates to the fatty group, such as coco, oleyl, tallow, or stearyl groups.
[0140] Examples of suitable secondary amines include dimethylamine, diethylamine, dipropylamine, dibutylamine, diamylamine, dihexylamine, diheptylamine, methylethylamine, ethylbutylamine and ethylamylamine. The secondary amines may be cyclic amines such as piperidine, piperazine and morpholine.
[0141] The amine may also be a tertiary-aliphatic primary amine. The aliphatic group in this case may be an alkyl group containing 2 to 30, or 6 to 26, or 8 to 24 carbon atoms. Tertiary alkyl amines include monoamines such as tert-butyl amine, tert-hexylamine, 1-methyl-1-amino-cyclohexane, tert-octylamine, tert-decylamine, tertdodecylamine, tert-tetradecylamine, tert-hexadecylamine, tert-octadecylamine, tert-tetracosanylamine, and tert-octacosanylamine.
[0142] In one embodiment the phosphorus acid amine salt includes an amine with C11 to C14 tertiary alkyl primary groups or mixtures thereof. In one embodiment the phosphorus acid amine salt includes an amine with C14 to C18 tertiary alkyl primary amines or mixtures thereof. In one embodiment the phosphorus acid amine salt includes an amine with C18 to C22 tertiary alkyl primary amines or mixtures thereof.
[0143] Mixtures of amines may also be used in the invention. In one embodiment a useful mixture of amines is “Primene® 81R” and “Primene® JMT.” Primene® 81R and Primene® JMT (both produced and sold by Rohm & Haas) are mixtures of C11 to C14 tertiary alkyl primary amines and C18 to C22 tertiary alkyl primary amines respectively.
[0144] In one embodiment oil soluble amine salts of phosphorus compounds include a sulphur-free amine salt of a phosphorus-containing compound which is obtained/obtainable by a process comprising: reacting an amine with either (i) a hydroxy-substituted di-ester of phosphoric acid, or (ii) a phosphorylated hydroxy-substituted di- or tri-ester of phosphoric acid. A more detailed description of compounds of this type is disclosed in International Application PCT/US08/051,126 (or equivalent to U.S. application Ser. No. 11/627,405).
[0145] In one embodiment the hydrocarbyl amine salt of an alkylphosphoric acid ester is the reaction product of a C14 to C18 alkyl phosphoric acid with Primene 81R™ (produced and sold by Rohm & Haas) which is a mixture of C11 to C14 tertiary alkyl primary amines.
[0146] Examples of hydrocarbyl amine salts of dialkyldithiophosphoric acid esters include the reaction product(s) of isopropyl, methyl-amyl (4-methyl-2-pentyl or mixtures thereof), 2-ethylhexyl, heptyl, octyl or nonyl dithiophosphoric acids with ethylene diamine, morpholine, or Primene 81R™, and mixtures thereof.
[0147] In one embodiment the dithiophosphoric acid may be reacted with an epoxide or a glycol. This reaction product is further reacted with a phosphorus acid, anhydride, or lower ester. The epoxide includes an aliphatic epoxide or a styrene oxide. Examples of useful epoxides include ethylene oxide, propylene oxide, butene oxide, octene oxide, dodecene oxide, and styrene oxide. In one embodiment the epoxide is propylene oxide. The glycols may be aliphatic glycols having from 1 to 12, or from 2 to 6, or 2 to 3 carbon atoms. The dithiophosphoric acids, glycols, epoxides, inorganic phosphorus reagents and methods of reacting the same are described in U.S. Pat. Nos. 3,197,405 and 3,544,465. The resulting acids may then be salted with amines. An example of suitable dithiophosphoric acid is prepared by adding phosphorus pentoxide (about 64 grams) at 58° C. over a period of 45 minutes to 514 grams of hydroxypropyl O,O-di(4-methyl-2-pentyl)phosphorodithioate (prepared by reacting di(4-methyl-2-pentyl)-phosphorodithioic acid with 1.3 moles of propylene oxide at 25° C.). The mixture is heated at 75° C. for 2.5 hours, mixed with a diatomaceous earth and filtered at 70° C. The filtrate contains 11.8% by weight phosphorus, 15.2% by weight sulphur, and an acid number of 87 (bromophenol blue).
[0148] The dithiocarbamate-containing compounds may be prepared by reacting a dithiocarbamate acid or salt with an unsaturated compound. The dithiocarbamate containing compounds may also be prepared by simultaneously reacting an amine, carbon disulphide and an unsaturated compound. Generally, the reaction occurs at a temperature from 25° C. to 125° C.
[0149] Examples of suitable olefins that may be sulphurised to form an the sulphurised olefin include propylene, butylene, isobutylene, pentene, hexane, heptene, octane, nonene, decene, undecene, dodecene, undecyl, tridecene, tetradecene, pentadecene, hexadecene, heptadecene, octadecene, octadecenene, nonodecene, eicosene or mixtures thereof. In one embodiment, hexadecene, heptadecene, octadecene, octadecenene, nonodecene, eicosene or mixtures thereof and their dimers, trimers and tetramers are especially useful olefins. Alternatively, the olefin may be a Diels-Alder adduct of a diene such as 1,3-butadiene and an unsaturated ester such as butyl acrylate.
[0150] Another class of sulphurised olefin includes fatty acids and their esters. The fatty acids are often obtained from vegetable oil or animal oil; and typically contain 4 to 22 carbon atoms. Examples of suitable fatty acids and their esters include triglycerides, oleic acid, linoleic acid, palmitoleic acid or mixtures thereof. Often, the fatty acids are obtained from lard oil, tall oil, peanut oil, soybean oil, cottonseed oil, sunflower seed oil or mixtures thereof. In one embodiment fatty acids and/or ester are mixed with olefins.
[0151] In an alternative embodiment, the antiwear agent may be a monoester of a polyol and an aliphatic carboxylic acid as described above. In one embodiment the monoester of a polyol and an aliphatic carboxylic acid may include glycerol monooleate, or mixtures thereof.
Antiscuffing Agent
[0152] The lubricant composition may also contain an antiscuffing agent. Antiscuffing agent compounds are believed to decrease adhesive wear and are often sulphur containing compounds. Typically the sulphur containing compounds include sulphurised olefins, organic sulphides and polysulphides, such as dibenzyldisulphide, bis-(chlorobenzyl)disulphide, dibutyl tetrasulphide, di-tertiary butyl polysulphide, sulphurised methyl ester of oleic acid, sulphurised alkylphenol, sulphurised dipentene, sulphurised terpene, sulphurised Diels-Alder adducts, alkyl sulphenyl N′N-dialkyl dithiocarbamates, the reaction product of polyamines with polybasic acid esters, chlorobutyl esters of 2,3-dibromopropoxyisobutyric acid, acetoxymethyl esters of dialkyl dithiocarbamic acid and acyloxyalkyl ethers of xanthogenic acids and mixtures thereof.
Extreme Pressure Agents
[0153] Extreme Pressure (EP) agents that are soluble in the oil include sulphur- and chlorosulphur-containing EP agents, chlorinated hydrocarbon EP agents and phosphorus EP agents. Examples of such EP agents include chlorinated wax; sulphurised olefins (such as sulphurised isobutylene), organic sulphides and polysulphides such as dibenzyldisulphide, bis-(chlorobenzyl)disulphide, dibutyl tetrasulphide, sulphurised methyl ester of oleic acid, sulphurised alkylphenol, sulphurised dipentene, sulphurised terpene, and sulphurised Diels-Alder adducts; phosphosulphurised hydrocarbons such as the reaction product of phosphorus sulphide with turpentine or methyl oleate; phosphorus esters such as the dihydrocarbon and trihydrocarbon phosphites, e.g., dibutyl phosphite, diheptyl phosphite, dicyclohexyl phosphite, pentylphenyl phosphite; dipentylphenyl phosphite, tridecyl phosphite, distearyl phosphite and polypropylene substituted phenol phosphite; metal thiocarbamates such as zinc dioctyldithiocarbamate and barium heptylphenol diacid; amine salts of alkyl and dialkylphosphoric acids or derivatives including, for example, the amine salt of a reaction product of a dialkyldithiophosphoric acid with propylene oxide and subsequently followed by a further reaction with P 2 O 5 ; and mixtures thereof (as described in U.S. Pat. No. 3,197,405).
[0154] Corrosion inhibitors that may be useful in the compositions of the invention include fatty amines, octylamine octanoate, condensation products of dodecenyl succinic acid or anhydride and a fatty acid such as oleic acid with a polyamine.
[0155] Foam inhibitors that may be useful in the compositions of the invention include copolymers of ethyl acrylate and 2-ethylhexylacrylate and optionally vinyl acetate; demulsifiers including tri alkyl phosphates, polyethylene glycols, polyethylene oxides, polypropylene oxides and (ethylene oxide-propylene oxide) polymers.
[0156] Pour point depressants that may be useful in the compositions of the invention include polyalphaolefins, esters of maleic anhydride-styrene copolymers, poly(meth)acrylates, polyacrylates or polyacrylamides.
[0157] As used herein the term “fatty alkyl” or “fatty” in relation to friction modifiers means a carbon chain having 10 to 22 carbon atoms, typically a straight carbon chain.
[0158] Friction modifiers that may be useful in the compositions of the invention include fatty acid derivatives such as fatty amines, esters, epoxides, fatty imidazolines, condensation products of carboxylic acids and polyalkylene-polyamines and amine salts of alkylphosphoric acids, fatty phosphonate esters and reaction products from fatty carboxylic acids reacted with guanidine, aminoguanidine, urea, thiourea, and salts thereof.
INDUSTRIAL APPLICATION
[0159] The method and lubricating composition of the invention may be utilised in refrigeration lubricants, greases, gear oils, axle oils, drive shaft oils, traction oils, manual transmission oils, automatic transmission oils, metal working fluids, hydraulic oils, or internal combustion engine oils. The gear oils, axle oils, drive shaft oils, manual transmission oils, automatic transmission oils may be collectively referred to as being used as part of a driveline device.
[0160] In one embodiment the method and lubricating composition of the invention may be for at least one of gear oils, axle oils, drive shaft oils, traction oils, manual transmission oils or automatic transmission oils.
[0161] An automatic transmission includes continuously variable transmissions (CVT), infinitely variable transmissions (IVT), toroidal transmissions, continuously slipping torque converter clutches (CSTCC), stepped automatic transmissions or dual clutch transmissions (DCT).
[0162] The gear oil or axle oil may be used in a planetary hub reduction axle, a mechanical steering and transfer gear box in a utility vehicle, a synchromesh gear box, a power take-off gear, a limited slip axle, and a planetary hub reduction gear box.
[0163] In one embodiment the copolymer of the invention in an axle oil provides antifoam performance.
[0164] In several embodiments a suitable lubricating composition includes the copolymer present (on an actives basis) in ranges as shown in the following table.
[0000]
TABLE
wt % of
wt % of Other
wt % of Oil of
Copolymer of the
Performance
Lubricating
Embodiments
Invention
Additives
Viscosity
A
0.1-70
0.5-20
10-99.4
B
1.5-65
0.5-15
20-98
C
10-60
0.5-15
25-89.5
D
15-60
0.5-15
25-84.5
E
18-46
0.5-15
39-81.5
[0165] In different embodiments the copolymer of the invention may be present at 0.1 wt % to 99.9 wt %, or 1 wt % to 70 wt %, or 1.5 wt % to 65 wt %, or 10 wt % to 60 wt %, or 15 wt % to 60 wt %, or 18 wt % to 46 wt %.
[0166] The following examples provide an illustration of the invention. These examples are non exhaustive and are not intended to limit the scope of the invention.
Examples
Polymer Intermediate 1
[0167] A 5 L flange flask is charged with 353 g of maleic anhydride, 606 g of 1-dodecene, and toluene (2372.8 g). The flask is fitted with a flange lid and clip, PTFE stirrer gland, rod and overhead stirrer, water-cooled condenser, thermocouple and nitrogen inlet. The flask is stirred under nitrogen. Trigonox®21S and toluene (315 g) are charged to a conical flask with side-arm and nitrogen is applied. The flask is heated to 105° C. The contents of the conical flask are charged to the flange flask via Masterflex™ pump (flow rate=1.2 ml/min −1 ) over a period of 5 hours. The flask is cooled to 50° C. A Dean-Stark trap is fitted to the flask and the flask is heated to 120° C. to remove toluene before alcohol addition. The flask is cooled to 110° C. Alfol®810 (417.6 g) and Tsofol®16 (2-hexyl-1-decanol, 174 g) are mixed and charged to the flask over 1.5 hours via dropping funnel. Alfol 810 (522 g) and methanesulphonic acid (24.7 g) are mixed together and charged to the flask via dropping funnel over 1.5 hours whilst heating to 145° C. The flask is stirred for 2 hours before cooling to ambient. The flask is heated to 145° C. The flask is stirred for a further 8 hours. A second methanesulphonic acid addition (12.4 g) is charged to the flask. A butanol addition (55.7 g) is then charged to the flask and stirred for 18 hours. A 2nd butanol addition is charged to the flask and stirred for 3 hours. A 3rd butanol addition is charged to the flask and stirred for 2.5 hours. A 4th butanol addition is charged to the flask and stirred for 18 hours. A 5th butanol addition is charged to the flask and stirred for 3 hours. A 6th butanol addition is charged to the flask and stirred for 3 hours. 16.82 g of sodium hydroxide (50 mol % in water) is charged to the flask whilst heating to 150° C. and left to stir for a further 45 minutes. 7.56 g of dimethylaminopropylamine (to deliver 0.1% nitrogen to the copolymer) is charged to the flask and then stirred for 2 hours. The apparatus is arranged for vacuum distillation. The flask is heated to 100° C. and vacuum is applied and held for 30 minutes. The flask is heated to 130° C. and held for 45 minutes. The flask is then heated to 150° C. and held for a further 3 hours. The flask is then cooled to 100° C. and vacuum removed. The product is filtered through diatomaceous earth to afford the desired ester copolymer having approx 0.1% N, 2 mg KOH/g TBN.
Polymer Intermediate 2
[0168] Ester copolymer 2 (Esc2) is prepared using the general procedure outlined above using 3-morpholinopropan-1-amine to deliver 0.12% nitrogen, 2.2 mg KOH/g TBN in place of dimethylaminopropylamine.
Polymer Intermediate 3
[0169] Ester copolymer 3 (Esc3) is prepared using the general procedure outlined above using dimethylaminopropylamine to deliver 0.27% nitrogen, 4.8 mg KOH/g TBN.
Polymer Intermediate 4
[0170] Ester copolymer 2 (Esc2) is prepared using the general procedure outlined above using 3-morpholinopropan-1-amine to deliver 0.25% nitrogen, approx 5 mg KOH/g TBN, in place of dimethylaminopropylamine.
Polymer Intermediate 5
[0171] Ester copolymer 3 (Esc3) is prepared using the general procedure outlined above dimethylaminopropylamine to deliver 5.6 mg KOH/g TBN.
Polymer Intermediate 6
[0172] Ester copolymer 5 (Esc5) is prepared using the general procedure outlined above using dimethylaminopropylamine to deliver 0.4% nitrogen, approx 8 mg KOH/g TBN.
Polymer Intermediate 7
[0173] Ester copolymer 2 (Esc2) is prepared using the general procedure outlined above using 3-morpholinopropan-1-amine to deliver 0.4% nitrogen, approx 8 mg KOH/g TBN, in place of dimethylamino-propylamine.
Phosphate Intermediate 1
[0174] A 250 ml 3 neck round bottom flask is charged with isooctanol (137.4 g) and the flask is fitted with thermocouple, magnetic follower, and nitrogen inlet (250 cm 3 /min), and the alcohol is warmed to 50° C. and stirred. A screw feed addition funnel (dried for 24 hours at 100° C.) is charged with phosphorus pentoxide (50 g) under a nitrogen blanket. The screw feed addition funnel is added to flask and phosphorus pentoxide is added over approx 1 hours maintaining the temperature between 50 to 58° C. The reaction flask is warmed to 90° C. and stirred for 5 hours and cooled to ambient temperature. The product has a TAN of 305.8 mg KOH/g.
Phosphate Intermediate 2
[0175] A 500 ml flange flask is fitted with overhead stirrer, water cooled condenser, screw feeder equipped with phosphorus pentoxide (81.88 g), a thermocouple, and a nitrogen inlet (250 cm 3 /min). The flask is charged with isooctanol (150 g) and 1,2-propanediol (43.90 g) and stirred at 300 rpm and warmed to 60° C. Phosphorus pentoxide is added to maintain the temperature 60 to 70° C. over 1 hour. The reaction mixture is warmed to 90° C. and held for 5 hours. The reaction mixture is cooled to 70° C. and held under vacuum (1 kPa or 10 mbar) for 3 hours. A light brown, clear fluid is obtained. The product has a TAN of 216.0 mg KOH/g.
Phosphate Intermediate 3
[0176] A 500 mL 3-necked round bottom flask is equipped with magnetic stirrer, thermocouple and solid addition hopper with a 2-neck adaptor with nitrogen purge line and a bubbler to keep the system under a constant nitrogen blanket. Oleyl glycolate (200.21 g) is charged to the flask and heated to 60° C. with stirring. Phosphorus pentoxide (58.76 g) is added to the solid addition hopper and packed down under the nitrogen blanket. The phosphorus pentoxide is then added slowly over 3 hours, controlling the exotherm to keep the temperature of the reaction between 55° C. and 65° C. The reaction is then left to cool overnight with a nitrogen purge. The next day the mixture is heated to 70° C. with stirring for 5 hours and cooled to room temperature affording the desired phosphate intermediate. The product has a TAN of 165.0 mg KOH/g.
Phosphate Intermediate 4
[0177] 2-ethylhexyl glycolate (39.44 g) is charged to 250 ml 3-necked round bottom flask fitted, magnetic follower, solid addition hopper charged with phosphorus pentoxide (9.93 g) under nitrogen. The 2-ethylhexyl glycolate is warmed to 60° C. and phosphorus pentoxide is added at such a rate as to maintain the temperature below 65° C. for 40 minutes. The reaction mixture is heated to 60° C. before heating to 70° C. and held for 2 hours. The product is a pale red/brown viscous oil. The product has a TAN of 201.6 mg KOH/g.
Phosphate Intermediate 5
[0178] all glassware is dried at 100° C. for 48 hours and constructed under nitrogen whilst hot. C 11-14 dialkyl tartrate (175 g) is charged to 500 ml 3-necked round bottom flask fitted with thermocouple, magnetic follower, solid addition hopper charged with phosphorus pentoxide (29.8 g) under nitrogen. The flask contents are stirred at 100 rpm at 55° C. and when at temperature the phosphorus pentoxide is added at such a rate as to maintain the temperature below 65° C. over a period of 40 minutes. The reaction mixture is heated to 60° C. and held for 4 hours before heating 70° C. and held for 2 hours. The reaction mixture is cooled and a pale red/brown viscous oil is obtained. The product has TAN 96 mg KOH/g.
Phosphate Intermediate 5a
[0179] all glassware is dried at 100° C. for 48 hours and constructed under nitrogen whilst hot. C 11-14 dialkyl tartrate (293.3 g) is charged to 500 ml 3-necked round bottom flask fitted with thermocouple, magnetic follower, solid addition hopper charged with phosphorus pentoxide (50 g) under nitrogen. The flask contents are stirred at 100 rpm at 50° C. and when at temperature the phosphorus pentoxide is added at such a rate as to maintain the temperature below 60° C. over a period of 40 minutes. The reaction mixture is heated to 50° C. and held for 18 hours before heating 70° C. and held for 1 hour. The reaction mixture is cooled and a pale red/brown viscous oil is obtained. The product has TAN 92.2 mg KOH/g.
Phosphate Intermediate 6
[0180] all glassware is dried at 100° C. for 48 hours and constructed under nitrogen whilst hot. C 11-14 dialkyl tartrate (255.51 g) is charged to 1 L flange flask fitted with thermocouple, water cooled condenser topped with bubbler, N 2 inlet at 100 cm 3 /min, and pressure equalising dropping funnel containing poly phosphoric acid, and the other port is blocked with a glass stopper. The dialkyl tartrate is warmed to 55° C. and stirred at 250 rpm at 55° C., and polyphosphoric acid (52.3 g) is added at such a rate as to maintain the temperature below 65° C. over a period of 30 minutes. The reaction mixture is heated to 60° C. for 4 hours and held for 4 hours. The flask is then heated to 70° C. and held for 2 hours. The product is a pale red/brown viscous oil. The product has a TAN (bromophenol blue) 120.0 mg KOH/g.
Phosphate Intermediate 7
[0181] A 500 ml flange flask is fitted with overhead stirrer, water cooled condenser, screw feeder equipped charged with phosphorus pentoxide (81.88 g), and a thermocouple. Isooctanol (225 g) is charged to the flask and stirred at 300 rpm and warmed to 60° C. Phosphorus pentoxide is added to maintain the temperature of 58 to 58° C. for a period of 1 hour. The reaction mixture is warmed to 90° C. and held for 5 hours and cooled to 38° C. and propylene oxide (55.60 g) is added subsurface over 1.5 hour and stirred for 2 hours. The flask is then cooled to 50° C. and phosphorus pentoxide (47.5 g) is added via screwfeeder over 1 hour. The flask is then heated to 90° C. and held with stirring for 5 hours. The flask is then cooled to ambient. The product is a coloured viscous liquid. The product has a TAN (bromophenol blue) of 180 mg KOH/g.
Phosphate Intermediate 8
[0182] A 500 ml flask is charged with glycerol monooleate (356.54 g), and iso-octanol (1130 g). The flask is fitted with a flange lid and clip, PTFE stirrer gland, rod and overhead stirrer, thermocouple, water-cooled condenser, nitrogen inlet port and powder dropping funnel. The flask is heated to 50° C. with stirring at 350 rpm. Phosphorus pentoxide (141.9 g) is charged to the dropping funnel under N 2 and then charged to the flask over one hour. The temperature is kept below 60° C. The flask is stirred at 50° C. for 18 hours. Vacuum (20-40 mbar) is applied to the reaction mixture for 2 hours to remove volatile components and the phosphate intermediate is then cooled to room temperature.
Final Product 1
[0183] phosphate intermediate 1 (20.10 g) is added to polymer intermediate 2 (2000 g) at 70° C. with stirring (250 rpm) under nitrogen and stirred for 2.5 hours. The desired product is isolated as a pale yellow, clear viscous liquid.
Final Product 2
[0184] phosphate intermediate 2 (20.29 g) is added to polymer intermediate 2 at 70° C. with stirring (250 rpm) under nitrogen and stirred for 1.5 hours. The product is isolated as a pale yellow, clear viscous liquid.
Final Product 3
[0185] phosphate intermediate 3 (26.5 g) is added to polymer intermediate 1 at 70° C. with stirring (250 rpm) under nitrogen and stirred for 1.5 hours. The product is isolated as a pale yellow, clear viscous liquid.
Final Product 3
[0186] A 5 litre flange flask is fitted with PTFE gasket, flange lid, nitrogen inlet 200 cm 3 /min, thermocouple, overhead stirrer with PTFE gland and double wall water cooled condenser. The flask is charged with polymer intermediate 2 (2065.6 g) and warmed to 70° C. and stirred at 350 rpm. The flask is charged with phosphate intermediate 4 (22.8 g). The charge takes approximately 5 minutes. The reaction contents are stirred for 7 hours at 70° C. and cooled to room temperature to afford a pale coloured viscous oily product.
Final Product 4
[0187] A 5 litre flange flask is fitted with PTFE gasket, flange lid, nitrogen inlet (200 cm 3 /min), thermocouple, overhead stirrer with PTFE gland and fitted with double wall water cooled condenser. The flask is charged with polymer intermediate 1 (3597.62 g) and the Phosphate Intermediate 5a (79.8 g) and stirred at 250 rpm, warming to 70° C. and held for 18 hours. The product is cooled to afford the desired product as a pale yellow viscous oil.
Final Product 5
[0188] A 5 litre flange flask is fitted with PTFE gasket, flange lid, nitrogen inlet (200 cm 3 /min), thermocouple, overhead stirrer with PTFE gland and fitted with double wall water cooled condenser. The flask is charged with polymer intermediate 3 (4079.54 g) and phosphate intermediate 5 (203.01 g) and stirred at 300 rpm, warming to 70° C. and hold for 20 hours. The product is cooled to room temperature to afford a pale yellow viscous oil.
Final Product 6
[0189] A 5 litre flange flask is fitted with PTFE gasket, flange lid, nitrogen inlet (200 cm 3 /min), thermocouple, overhead stirrer with PTFE gland and fitted with double wall water cooled condenser. The flask is charged with polymer intermediate 3 (3000 g) and phosphate intermediate 6 (119 g) and stirred at 300 rpm, warmed to 80° C. and held for 4 hours. The product is cooled to room temperature to afford a pale yellow viscous oil.
Final Product 7
[0190] O,O-bis(4-methylpentan-2-yl) S-hydrogen phosphorodithioate (22.09 g, TAN 198.1 mg KOH/g) is added to polymer intermediate 2 at 70° C. over 20 minutes with stirring (250 rpm) under nitrogen and stirred for 4 hours. The product is isolated as a pale yellow, clear viscous liquid.
Final Product 8
[0191] to a 5 l flange flask fitted with overhead stirrer, nitrogen inlet (200 cm 3 /min), water cooled condenser and thermocouple is added polymer intermediate 3 (1000 g), C12-14 dialkyl tartrate (31.76 g) and 115% polyphosphoric acid (21.69 g). The reaction mixture is stirred at 300 rpm and warmed to 80° C. The reaction mixture is stirred for 1 hour and isooctanol (29.83 g) is added and stirred for 17 hours. To the reaction mixture is added polymer intermediate (2000 g) over 40 minutes, stirred 3 hours and cooled to room temperature to afford final product 8 as a viscous oil.
Final Product 9
[0192] Polymer intermediate 5 (25278 g) is stirred at 167 rpm, under 0.2 kg/h N 2 for 1 hours and C12-14 dialkyl tartrate (576.55 g) is added in one portion. Then the reactants are stirred overnight and polyphosphoric acid (190.89 g) is charged via manway. Stir 30 minutes and heat to 80° C. and stir for 4.5 hours. Butanol (83.01 g) is added via sampling pot, rinsed pot several times with reaction mixture and stirred 50 minutes, heat to 100° C. Stir for 1.75 hours and cool to room temperature. The reaction mixture is filtered through diatomaceous earth (180 g) at 85° C. for 30 minutes and increase to 100° C. for 45 minutes. The product is a viscous amber oil.
Final Product 10
[0193] phosphate intermediate 7 (24.29 g) is added to polymer intermediate 6 (2000 g) at 70° C. with stirring (250 rpm) under nitrogen and stirred for 1.5 hours. The desired product is isolated as a pale yellow, clear viscous liquid, Yield: 2024 g.
Final Product 11
[0194] phosphate intermediate 5 (47.4 g) is added to polymer intermediate 2 (2000 g) at 70° C. with stirring (250 rpm) under nitrogen and stirred for 3 hours. The product is a dark brown viscous oil.
[0000] Study 1: Manual Transmission Lubricant with about 300 ppm Phosphorus
[0195] Comparative manual transmission lubricant 1 (CMTL1) contains 75.2 wt % PAO-4 (polyalphaolefin 4 mm 2 /s (cSt)) base oil, 18.8 wt % of a viscosity modifier of Polymer intermediate 2 (i.e., a polymer that has not been phosphated), 0.35 wt % of a phosphorus antiwear agent, and the balance to 100 wt % of other conventional manual transmission lubricant additives. The lubricant has a phosphorus level of 310 ppm.
[0196] Inventive manual transmission lubricant 1 (IMTL1) contains 75.2 wt % PAO-4 (polyalphaolefin 4 mm 2 /s (cSt)) base oil, 19.0 wt % of a viscosity modifier based on the product of final product 2, 0.075 wt % of a phosphorus antiwear agent, and the balance to 100 wt % of other conventional manual transmission lubricant additives. The lubricant has a phosphorus level of 296 ppm.
[0197] CMTL1 and IMTL1 are evaluated by the methodology of ASTM Method D4172 (4-ball wear test), and FZG A10/16.6R/90 spur gear scuffing evaluation. The results obtained are as follows:
[0000]
CMTL1
IMTL1
4 ball wear scar (mm)
0.453
0.344
FZG revolutions at point of failure
7956
21,700
(Load stage 6)
Weight loss pin (mg)
213
114
Weight loss of wheel (mg)
302
148
[0198] The results indicate that the lubricating composition of the present invention has reduced wear in the 4 ball wear test and has prolonged durability in the FZG, indicating improved scuffing and wear resistance.
[0000] Study 2: Manual Transmission Lubricant with about 500 ppm Phosphorus
[0199] Comparative manual transmission lubricant 2 (CMTL2) contains 75.8 wt % PAO-4 (polyalphaolefin 4 mm 2 /s (cSt)) base oil, 18.8 wt % of a viscosity modifier based of Polymer intermediate 2, 0.6 wt % of a phosphorus antiwear agent, and the balance to 100 wt % of other conventional manual transmission lubricant additives. The lubricant has a phosphorus level of 532 ppm.
[0200] Inventive manual transmission lubricant 2 (IMTL2) contains 76.1 wt PAO-4 (polyalphaolefin 4 mm 2 /s (cSt)) base oil, 18.8 wt % of a viscosity modifier based on the product of final product 11, 0.3 wt % of a phosphorus antiwear agent, and the balance to 100 wt % of other conventional manual transmission lubricant additives. The lubricant has a phosphorus level of 499 ppm.
[0201] CMTL2 and IMTL2 are evaluated by the methodology of ASTM Method D4172 (4-ball wear test). The results obtained are:
[0000]
CMTL2
IMTL2
4 ball wear scar (mm)
0.464
0.349
[0202] The results indicate that that the lubricating composition of the present invention has reduced wear in the 4 ball wear test when phosphorus content of the lubricant is about 500 ppm.
[0000] Study 3: Automotive Gear Oil with about 800 ppm Phosphorus
[0203] Comparative automotive gear oil 1 (CAG1) contains 49.3 wt % PAO-4 (polyalphaolefin 4 mm 2 /s (cSt)) base oil, 46 wt % of a viscosity modifier of Intermediate Polymer 2, 1 wt % of a phosphorus antiwear agent described in above, and the balance to 100 wt % of other automotive gear oil lubricant additives. The lubricant has a phosphorus level of 839 ppm.
[0204] Inventive automotive gear oil 1 (IAG1) contains 49.9 wt % PAO-4 (polyalphaolefin 4 mm 2 /s (cSt)) base oil, 46 wt % of a viscosity modifier of Final Product 4, 0.4 wt % of a phosphorus antiwear agent described in [0112] above, and the balance to 100 wt % of other conventional manual transmission lubricant additives. The lubricant has a phosphorus level of 788 ppm.
[0205] CAG1 and IAG1 are evaluated for the capability for load-carrying, wear, and extreme pressure properties in a hypoid axle under conditions of low-speed, high-torque operation using ASTM method D6121-05a. The results obtained are presented in the table below.
[0206] The results in the table below indicate an automotive gear oil lubricant containing the composition of the present invention overall has reduced wear in ring and pinion. In particular, reduction in wear observed in ring gear ridging and pinion gear pitting/spalling.
[0000]
ASTM D6121-05a
Rating
Parameter Rated
CAG1
IAG1
Ring Gear
Final Wear Rating
7
7
Final Surface Fatigue Rippling
10
10
Final Surface Fatigue Ridging
9
10
Final Surface Fatigue Pitting and Spalling Merit
9.9
9.9
Final Surface Fatigue Scoring
10
10
Wear Pinion Gear
Final Rating
8
6
Final Rippling
9
9
Final Ridging
9
9
Final Scoring
9.3
9.8
Final Pitting and Spalling Merit
10
10
[0207] It is known that some of the materials described above may interact in the final formulation, so that the components of the final formulation may be different from those that are initially added. The products formed thereby, including the products formed upon employing lubricant composition of the present invention in its intended use, may not be susceptible of easy description. Nevertheless, all such modifications and reaction products are included within the scope of the present invention; the present invention encompasses lubricant composition prepared by admixing the components described above.
[0208] As used herein, the term “hydrocarbyl substituent” or “hydrocarbyl group” is used in its ordinary sense, which is well-known to those skilled in the art. Specifically, it refers to a group having a carbon atom directly attached to the remainder of the molecule and having predominantly hydrocarbon character. Examples of hydrocarbyl groups include: hydrocarbon substituents, including aliphatic, alicyclic, and aromatic substituents; substituted hydrocarbon substituents, that is, substituents containing non-hydrocarbon groups which, in the context of this invention, do not alter the predominantly hydrocarbon nature of the substituent; and hetero substituents, that is, substituents which similarly have a predominantly hydrocarbon character but contain other than carbon in a ring or chain. A more detailed definition of the term “hydrocarbyl substituent” or “hydrocarbyl group” is described in paragraphs [0137] to [0141] of published application US 2010-0197536.
[0209] Except in the Examples, or where otherwise explicitly indicated, all numerical quantities in this description specifying amounts of materials, reaction conditions, molecular weights, number of carbon atoms, and the like, are to be understood as modified by the word “about.” Unless otherwise indicated, each chemical or composition referred to herein should be interpreted as being a commercial grade material which may contain the isomers, by-products, derivatives, and other such materials which are normally understood to be present in the commercial grade. However, the amount of each chemical component is presented exclusive of any solvent or diluent oil, which may be customarily present in the commercial material, unless otherwise indicated.
[0210] Each of the documents referred to above is incorporated herein by reference. It is to be understood that the upper and lower amount, range, and ratio limits set forth herein may be independently combined. Similarly, the ranges and amounts for each element of the invention may be used together with ranges or amounts for any of the other elements.
[0211] While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims. | The invention relates to polyester quaternary ammonium salts, including amine, amide, and ester salts, processes for making them, and their use as additives, including their use in fuels, such as diesel fuel and fuel oils. The invention particularly relates to the use of polyester quaternary ammonium salts as detergents in fuels and the methods of making them. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a facsimile apparatus having an error correction mode, and especially to a facsimile apparatus which can reduce the time necessary for the procedure between pages and the subsequent procedure (a procedure subsequent to the last page image information transmission procedure) for communication.
In prior facsimile apparatuses, generally, image information is transmitted at a high speed of, for example, 14.4 Kbps or the like, and other control signals are transmitted at a low speed of about 300 bps. In FIGS. 11 to 15, transmission procedures in an error correction mode of a facsimile apparatus having the error correction mode are shown. As is widely known, the error correction mode is a mode in which image information, having errors caused by noises, is sent again to a receiving side at its request, so that the receiving side can correctly receive the image information.
FIG. 11 shows a single page image information transmission procedure in which: when a transmission side dials and a communication line is connected with a receiving side, a CED signal (a called station identification signal) is sent from the receiving side to the transmission side at 300 bps; and next, an NSF signal (a nonstandard device signal), a CSI signal (a called station identification signal), and a DSI signal (a digital identification signal) are sent to the transmission side. Next, a TSI signal (a transmission station identification signal), and a DCS signal (a digital command signal) are sent from the transmission side to the receiving side.
When the preceding procedure (a procedure preceding the first page image information transmission procedure) has been completed as described above, a training signal T is sent from the transmission side at high speed, and a transmission speed of the image information is determined thereby. After that, the image information is divided into n frames, and the frames, from frame 1 to frame n, are successively sent to the receiving side. When the image information has been sent out, an RCP signal (a Return to Control for Partial Page signal) is sequentially sent out three times.
Next, a preamble Pr and a PPS-EOP signal (a Partial Page Signal-End Of Page signal, an EOP signal being a procedure completion signal) are sent out. This signal includes information by which the number of transmitted frames of image information is shown. Next, the preamble Pr and an MCF signal (a message confirmation signal) are sent out from the receiving side.
After the transmission side has received the above signals, the transmission side sends the preamble Pr and a DCN signal (a disconnection command signal), and thereby the communication line is disconnected and the communication is completed. In these communication procedures, a procedure subsequent to the RCP signal takes a relatively long period of time, 3.805 s, in the example. This is because each control signal is transmitted at the low speed of 300 bps so that communication can be surely performed.
FIG. 12 shows a multi-page transmission procedure, which is a communication procedure when a mode, such as resolution or density, is not changed. In the explanation of the example, the preceding procedure will be neglected hereinafter. In the drawing, after the transmission side has sent out the n-th page image information subsequent to the training signal, the RCP signals are successively sent out three times. Next, the transmission side sends out the preamble Pr and a PPS-MPS signal (a PPS-Multi Page Signal, an MPS signal being a multi-page signal). The PPS-MPS signal shows that image information of the n-th page has been transmitted and the control returns to phase C.
After receiving the above signals, the receiving side sends out the preamble and the MCF signal. Subsequently, the transmission side sends the training signal T, and next, sends the image information of the (n+1)th page. After the information of all pages has been sent out, the subsequent procedure is carried out in the same way as shown in FIG. 11, and communication is completed. In this case, the procedure between pages is also carried out at the transmission speed of 300 bps, and it takes 1.745 s.
FIG. 13 shows a transmission procedure when a mode is changed in the multi-page transmission. In this case, the transmission side sends a PPS-EOM signal (an EOM signal: an end of message signal) at the transmission speed of 300 bps in the procedure between pages. After the receiving side has sent the MCF signal, a waiting time of 6 s is provided for a modal change in the receiving side, and after that, the receiving side sends the NSF signal, CSI signal, and DIS signal in the same way as the foregoing.
After receiving the above signals, the transmission side sends the TSI signal and DCS signal. Next, the training signal T is sent out and the transmission speed is determined. After that, the image information of the (n+1)th page is sent out. After the image information of all pages has been sent out, the same procedure as shown in FIG. 11 is carried out and the communication is completed. In this case, the procedure between pages takes 8.57 s.
FIG. 14 shows a transmission procedure when an error frame is generated. In this case, the transmission side sends the preamble Pr and a PPS-XXX signal (XXX means any of EOP, MPS or EOM) in the procedure between pages, and next, the receiving side sends the preamble Pr and a PPR signal (a Partial Page Request signal). Information of a frame number in which an error has occurred, for example, a frame number 5 or 8, is included in the PPR signal.
After receiving the error frame information, the transmission side sends again the frame in which an error has occurred. Thereby, image information containing no error can be sent and received. In this case, the procedure between pages takes 3.485 s. The subsequent procedures are performed in the same way as shown in FIG. 11.
FIG. 15 shows a transmission procedure in the case where an error frame has been generated and a fall back is performed, that is, in the case where a transmission speed is lowered when the error has occurred. In the drawing, in the case where an error has occurred when the n-th page image information has been sent, for example, at the transmission speed of 14.4 Kbps, the PPS-XXX signal is sent in the same way as shown in FIG. 14 from the transmission side, and next, the PPR signal is sent from the receiving side.
Subsequent to the foregoing, the transmission side sends the preamble Pr and a CTC signal (a Continue To Correct signal). In the CTC signal, information of the transmission speed of the next image information is included. In this case, a transmission speed lower than the preceding transmission speed of 14.4 Kbps, for example, 9.6 Kbps is set. After receiving the signal, the receiving side sends the preamble Pr and a CTR (Response for Continue to Correct) signal. The CTR signal means that the CTC signal has been received.
Due to the foregoing, the procedure between pages is performed in the time of 6.005 s. After that, information of a frame in which an error has occurred is sent again at the transmission speed of 9.6 Kbps. Thus, when an error occurs, the transmission speed is lowered one step by one step, and communication is performed. The subsequent procedure is performed in the same way as shown in FIG. 11.
As described above, in the prior facsimile apparatus having an error correction mode, the image information and the RCP signal are sent out at the high transmission speed of 14.4 Kbps the maximum, and other control signals except the RCP signal are sent at a low transmission speed of 300 bps, so that the procedure between pages and the subsequent procedure take a relatively long time. Especially, when it is necessary to send information of a lot of pages, it takes a long time to transmit the information, so that the communication costs are increased.
SUMMARY OF THE INVENTION
The present invention has solved the above-described problem, and the object of the invention is to provide a facsimile apparatus which can reduce transmission time.
In order to solve the above-described problem, a facsimile apparatus having an error correction mode of the first embodiment is characterized in that: a period of time in which a procedure between pages and a subsequent procedure are performed can be reduced by the method in which page information, such as resolution or paper width, and a post message command indicating completion of page transmission and the next procedure, are sent from an image information transmission side at the same transmission speed as that of the image information.
The facsimile apparatus having an error correction mode of the second embodiment is characterized in that: a period of time in which a procedure between pages is performed can be reduced by the method in which retransmission of page information or a post message command of the page in which an error has occurred, and transmission of the next transmission speed are required, from the receiving side to the transmission side, when the error has occurred in page information, including resolution and paper width, or in the post message con, hand indicating the completion of transmission of the page information, and the next procedure.
Reduction of the subsequent procedure will be described as follows. In FIG. 2, after the preceding procedure (not shown in the drawing) has been performed, the training signal T, the page information and the image information (frame 1 to frame n) are sent at a high transmission speed (14.4 Kbps to 2.4 Kbps) from the transmission side. After that, three sequential post command messages (PPS-EOP signal) are sent at the same transmission speed as that of the image information. Information with respect to the completion of transmission of the image information is included in the PPS-EOP signal.
Next, the preamble Pr and the MCF signal are sent from the receiving side. After receiving the signals, the transmission side sends the preamble Pr and the DCN signal, and connection with a communication line is disconnected, communication being completed. In this case, the PPS-EOP signal, which has been conventionally sent at the transmission speed of 300 bps in the subsequent procedure, is sent at higher transmission speed, and thereby the time necessary for the subsequent procedure can be reduced by 2.335 s (=3.805-1.47) compared with the time necessary for the conventional method.
Next, reduction of the procedure between pages will be described as follows. In FIGS. 3 and 4, three sequential post message commands (PPS-MPS signal or PPS-EOM signal) are sent subsequent to the n-th page image information at a high transmission speed from the transmission side, and next, the Pr and MCF signals are sent at the transmission speed of 300 bps. After receiving the signals, the transmission side sends an (n+1)th page image information at a high transmission speed. In this case, the PPS-MPS signal, which has been conventionally sent at the transmission speed of 300 bps (refer to FIGS. 12 and 13), is sent at the high transmission speed, and thereby the time necessary for the procedure between pages can be greatly reduced.
When an error has occurred in the image information, three sequential PPS-EOP signals are sent subsequent to the image information at a high transmission speed from the transmission side as shown in FIG. 5 and FIG. 7. After receiving the signals, the receiving side sends the preamble signal Pr and an extended PPR signal at the transmission speed of 300 bps. As shown in FIG. 6, the extended PPR signal includes a frame number, a page information, a PPS-XXX signal, and a transmission speed, which are to be retransmitted.
Due to the foregoing, the information in which an error has occurred, can be retransmitted. In this case, the receiving side requires a signal including a transmission speed or other information, and therefore, the time necessary for transmission and reception of control signals can be reduced to the minimum. Accordingly, the time necessary for the procedure between pages can be greatly reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a structure of the facsimile apparatus of the present invention.
FIG. 2 is a view illustrating a transmission procedure in single page transmission in the facsimile apparatus of the example.
FIG. 3 is a view illustrating a transmission procedure at the time of no modal change in the case of multi-page transmission in the facsimile apparatus of the example.
FIG. 4 is a view illustrating a transmission procedure at the time of a modal change in the case of multi-page transmission in the facsimile apparatus of the example.
FIG. 5 is a view illustrating a transmission procedure at the time when an error frame exists in the facsimile apparatus of the example.
FIG. 6 is a view illustrating an extended PPR signal.
FIG. 7 is a view illustrating a transmission procedure at the time when a fall back is performed in the case where an error frame exists in the facsimile apparatus of the example.
FIG. 8 is a view illustrating a transmission procedure in the case where an abnormal command is received in the facsimile apparatus of the example.
FIG. 9 is a view illustrating a transmission procedure in the case where page information collapsing occurs in the facsimile apparatus of the example.
FIG. 10 is a view illustrating a transmission procedure in the case where control information collapsing occurs in the facsimile apparatus of the example.
FIG. 11 is a view illustrating a transmission procedure in the case of single page transmission in a conventional facsimile apparatus.
FIG. 12 is a view illustrating a transmission procedure at the time of no modal change in the case of multi-page transmission in the conventional facsimile apparatus.
FIG. 13 is a view illustrating a transmission procedure at the time when a modal change exists in the case of multi-page transmission in the conventional facsimile apparatus.
FIG. 14 is a view illustrating a transmission procedure in the case where an error occurs in a conventional facsimile apparatus.
FIG. 15 is a view illustrating a transmission procedure at the time of a fall back in the case where an error occurs in a conventional facsimile apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, an example of a facsimile apparatus of the present invention will be described in detail as follows.
FIG. 1 shows a structure of a facsimile apparatus according to the present invention. In FIG. 1, numeral 11 denotes a CPU which controls transmission, numeral 12 denotes a ROM in which each kind of control program, such as a program for transmission and for reception, is stored, and numeral 13 denotes a RAM in which image information to be transmitted and other information are stored.
After the image information read by an image reading unit 14 is stored in the RAM 13 through an interface 15 or directly, the image information is sent to a modem which functions as a transmission and reception means, and to a network control unit (NCU) 16. Image information which is inputted from a communication line is stored in the RAM 13 through the modem and the NCU 16, or is sent to a recording unit 18 which functions as a printer, directly through an interface 17, and recorded thereby.
Information such as a telephone number of a receiver, is sent to a display unit 20 through an interface 19 and displayed thereon. An operation unit 21 is provided with a plurality of keys (not shown in the drawing). When the keys are operated, the content of information inputted by the keys is inputted into the CPU 11 through an interface 22.
Next, referring to FIGS. 2 to 10, a transmission procedure in the case of an error correction mode in the facsimile apparatus will be described as follows. In this case, an explanation of the preceding procedure is omitted because it is the same as that in the foregoing.
FIG. 2 shows a transmission procedure in the case of single page transmission, in which a training signal T is sent from the transmission side at a transmission speed of 14.4 Kbps, and next, page information is sent at the transmission speed of 14.4 Kbps. This page information includes the content which is contained in a DCS signal sent in the preceding procedure, that is, paper width, coding method, and line density. Next, image information is sent out, and after that, three sequential PPS-EOP signals are sent at the same high transmission speed as that of the image information.
Next, a preamble Pr and an MCF signal are sent from the receiving side at a low transmission speed of 300 bps. After the signals have been received, the transmission side sends the preamble Pr and a DCN signal, and thereby connection with the communication line is disconnected and communication is completed. According to the transmission procedure, the time necessary for the subsequent procedure is 1.47 s, and thereby it can be reduced by 2.335 s (=3.805-1.47) as compared with that of a conventional method (FIG. 11).
In the case of single page transmission, page information is contained in the DCS signal of the preceding procedure, and therefore, the page information which is sent before the image information can be neglected. However, in this specification, the page information is sent in order to comply with other cases.
FIG. 3 shows a transmission procedure in the case of multi-page transmission when no mode is changed. In this case, the training signal T, the page information, and n-th page image information are sent at a high speed in the same way as that in FIG. 2, and after that, three sequential PPS-MPS signals are sent at the high transmission speed. Next, the receiving side sends out the preamble Pr and the MCF signal. After receiving the signals, the transmission side sends the training signal T, and (n+1)th page information at high transmission speed. Here, the (n+1)th page information is neglected because it is the same as that of n-th page. In this case, time for the procedure between pages can be reduced by 0.935 s (=1.745-0.81) as compared with that of a conventional method.
FIG. 4 shows a transmission procedure in the case of multi-page transmission when a mode is changed. In this case, the training signal T, page information and n-th page image information are sent at a high transmission speed, and after that, three sequential PPS-EOM signals are sent at the same transmission speed as that of the image information. Next, the receiving side sends the preamble Pr and an MCF signal. After receiving the signals, the transmission side sends the training signal, the (n+1)th page information, and the second page image information. In this case, time necessary for the procedure between pages can be reduced by 7.76 s (=8.57-0.81).
FIG. 5 shows a transmission procedure in the case of single page transmission when an error has occurred. In this case, the training signal T, the page information and the image information are sent at a high transmission speed after the preceding procedure. Next, three sequential PPS-EOP signals are sent at a high transmission speed.
In this case, an error has occurred in the image information, and the receiving side sends the preamble Pr and an extended PPR signal. The extended PPR signal is defined as a nonstandard signal in the present invention, in which, as shown in FIG. 6, a request for retransmission of the page information, a PPS-XXX signal, and the transmission speed, is added to a standard PPR signal.
That is, a frame of the extended PPR signal is composed of an address A, a control field C, a facsimile control field FCF, and a facsimile information field FIF (retransmission information bit map). FCF contains information showing that this signal is the extended PPR signal. FIF contains the number of the error frame, information whether an error has occurred or not in the page information, information whether an error has occurred or not in the PPS-XXX signal, and a transmission speed when an error has occurred.
A binary number [0] is set in bits of the frame of the image information, the page information, the control signal, and the transmission speed which have been correctly received in the extended PPR signal. A binary number [1] is set in bits in which an error has occurred. When the extended PPR signal is received, the transmission side sends the training signal T and required frames. Due to the foregoing, information of all pages are sent, and next, the same subsequent procedure as that in FIG. 2 is carried out, and the communication is completed. In this case, the time necessary for the procedure between pages can be reduced by 1.835 s (=3.485-1.65).
FIG. 7 shows the transmission procedure in the case where an error has occurred and a fall back is carried out. In this case, the transmission side sends the training signal T, the page information, the n-th page image information at a high transmission speed of, for example, 14.4 Kbps, and next, three sequential PPS-XXX signals are sent at the transmission speed of 14.4 Kbps. Next, the receiving side sends the preamble Pr and the extended PPR signal. The transmission speed of, for example, 9.6 Kbps of the next image information is contained in the extended PPR signal. That is, in this case, the receiving side requires the information of the transmission speed of the image information.
After receiving the signals, the transmission side sends the training signal T and the required frames at the transmission speed of 9.6 Kbps. Thus, after the image information of all pages has been sent, the same subsequent procedure as that in FIG. 2 is carried out, and communication is completed. In this case, the time required for the procedure between pages can be reduced by 4.355 s (=6.005-1.65). In this case, when an error has occurred even when the transmission speed of the image information is lowered to, for example, 2.4 Kbps, it is regarded as a fall-back-over, and therefore, the transmission side may send a DCN signal to finish the communication. This is because low speed communication does not comply with the time shortening which is a main object of the present invention.
FIGS. 8 to FIGS. 10 show transmission procedures in the case where abnormality has occurred in the communication. FIG. 8 shows the transmission procedure in the case where page information which is outside the capacity of communication, for example, resolution which is outside the capacity of the transmission side, has been indicated, or an abnormal signal, the meaning of which can not be understood, has been received. In this case, the receiving side sends the DCN signal in the middle of reception of the signal, and disconnects the connection with the communication line.
The transmission side sends the image information and the PPS-XXX signal at a high transmission speed in the same way as in the case of normal communication. Then, since the answer with respect to the signal is not sent from the receiving side, the PPS-XXX signal is sent two times over a time interval at the transmission speed of 300 bps. Since the answer is not sent from the receiving side even in this case, the transmission side sends the DCN signal, and thereby the communication is finished.
FIG. 9 shows the transmission procedure in the case where the page information or the image information has been collapsed, and has not been able to be received normally. In this case, the PPS-XXX signal is sent at a high transmission speed subsequent to the image information, and next, the receiving side sends the preamble Pr and the extended PPR signal at the transmission speed of 300 bps. As described above, the page information or the number of frames of the image information in which an error has occurred, is contained in the extended PPR signal. After receiving the signal, the receiving side transmits again the training signal T, the page information which is required for retransmission, and the image information at a high transmission speed. The subsequent procedure is the same as that in FIG. 2.
FIG. 10 shows the transmission procedure in the case where the PPS-XXX signal has been collapsed and has not been able to be received. In this case, since the PPS-XXX signal can not be received, the receiving side sends the preamble Pr and the extended PPR signal at 300 bps. After receiving the signals, the transmission side sends the PPS-XXX signal at the transmission speed of 300 bps. In this case, when an error does not exist in the page information and the image information, the receiving side sends the preamble Pr and the MCF signal at the transmission speed of 300 bps. Next, the transmission side sends the training signal T and the (n+1)th page image information. The subsequent procedure is the same as that in FIG. 2. In this case, time necessary for the procedure between pages can be reduced by 2.59 s (=5.57- 2.98) as compared with that of the conventional procedure between pages.
When an error has occurred in the page information or the image information, the receiving side sends the preamble Pr and the extended PPR signal after receiving the PPS-XXX signal, and thereby the page information or the image information in which an error has occurred, is required to be transmitted again. After receiving the signals, the transmission side transmits again the information.
As described above, in the first embodiment, the page information and the post command message are sent from the transmission side at the same transmission speed as that of the image information. Therefore, according to the first embodiment, the time required for transmission and reception of control signals which are carried out within a period of time necessary for the procedure between pages and the subsequent procedure, can be reduced to the minimum. As a result, the first embodiment is effective for reduction of the communication time and the communication cost.
Further, in the second embodiment, when an error has occurred in the image information, page information or post command message, the information in which an error has occurred, and its transmission speed are required to be sent from the receiving side to the transmission side. According to the second embodiment, the time necessary for transmission and reception of control signals which are carried out within the period of time necessary for the procedure between pages when an error has occurred can be reduced to the minimum. Therefore, the second embodiment is effective for reduction of the communication time and the communication cost. | A facsimile apparatus in a first station with an error correction mode retransmits signal again in response to a request from a section station. The facsimile apparatus includes a CPU to control a transmission speed of the signal transmission circuit so as to transmit operation control signals such as page information signals relating to a document and post message command signals indicating an operation that is to follow a present operation, at a first transmitting speed that corresponds to a transmission speed used to transmit image signals. | 7 |
BACKGROUND OF THE INVENTION
The present invention is directed to a device for driving nails or similar fastening elements and includes a driving member rotated by a motor, a driven member including means for converting rotational movement into translational movement for a driver rod, and a clutch for transmitting torque from the driving member to the driven member.
Driving devices powered by a variety of power sources are known for driving nails or similar fastening elements. For example, compressed air, combustion gases or electrical current may serve as the power source. While compressed air devices provide only a low output and require a supply of compressed air often not available at a construction site, in the case of devices powered by combustion gases there is a certain safety risk due to the danger of explosion of the gases. Electrically driven devices do not have any of these disadvantages. A known driving device, powered by an electric motor, has a driving member rotated by the motor and an output member which can be coupled with it for the transmission of the rotational movement. The output or driven member is connected with a driver rod by a part in the form a coiled flat spring. When the driven end is rotated in one direction, the spring band is unwound and the driver rod is displaced in the driving direction. The return movement of the driver rod is effected by a separate device.
The driving member is a satellite of a planetary gear with the satellite in meshed engagement with the inner gear system of a ring gear. A pin supported in the center of the satellite engages with the driven member.
When the device is idling, the ring gear is freely rotatable so that rotation of the satellite around its axis causes rotation of the ring gear. By pressing the device against a work surface, the ring gear is prevented from turning in the housing by a sensing element and a clamping spring whereby the satellite, rotating around its own axis, rolls on the internal gearing of the ring gear and, as a result, rotates around the axis of the driving pinion forming the sun gear. Accordingly, the satellite provides rotational movement to the driven member.
A disadvantage of this driving device is that the driving force as well as the length of the driving stroke is determined by the intensity and the time period during which the device is pressed against the work surface. These factors are influenced manually by the operating personnel. Further, the return movement of the driving rod into its initial position is not possible via the driven member and, as a result, the above-mentioned separate means are required.
SUMMARY OF THE INVENTION
Therefore, the present invention is directed to a motor driven driving device of a simple construction which affords a complete drive stroke and return stroke of the drive rod without being influenced by outside factors.
In accordance with the present invention, a clutch for transmitting torque from the driving member to the driven member is selectively connectible with the two members by an actuating or triggering device for establishing a limited timewise connection of the clutch with the driving member and the driven member.
The engagement of the clutch with the driving member and the driven member must be maintained from the commencement of the drive stroke until the end of the return stroke so that the connection is limited to a given time period. A releasing device is provided for activating the clutch. Based on the arrangement of the device for converting the rotational movement to translational movement for the drive rod, the connection of the drive member and the driven member can be maintained over a part of a revolution, or for a complete revolution or several revolutions of the drive member. By actuating the releasing device, an automatically sequenced work cycle constituted by a driving stroke and a return stroke of the drive rod occurs.
Shiftable freewheeling clutches are suitable. Preferably, the clutch is designed as a partial revolution, a single revolution, or a multiple revolution clutch. A partial revolution clutch affords a connection between the driving member and the driven member only during a specific defined partial section of a revolution of the driving member. A single revolution clutch, however, maintains the connection during one complete revolution of the driving member. In a multiple revolution clutch the connection is maintained during a plurality of revolutions of the driving member.
It is advantageous if the clutch is a wraparound spring. The block of windings of the spring embraces the circumferential surfaces of a hub section on the driving member and another hub section on the driven member. Each hub section has an outer cylindrical shape of the same diameter, although a conical outer contour would be possible. The front ends of the hub sections facing one another are spaced as closely as possible without any mutual contact, to assure a wear-free rotation of the driving member with respect to the driven member while the device idles. The inside diameter of the windings of the slackened spring can be slightly smaller than the outside diameter of the circumferential surfaces of the hub sections. As a result, when the clutch is engaged the spring windings contact, with a slight prestressing, the circumferential surfaces of the hub sections. By rotating the driving member opposite to the winding direction of the wraparound spring, which is the operational direction of rotation of the driving member, the spring engages in a friction locking manner around the circumferential surfaces of the hub sections with a cable friction effect. For disengagement of the clutch the windings of the spring are arranged so that they do not tightly wrap around the hub sections. At most, only a frictional moment caused by prestressing of the wrap around spring acts on the hub sections.
Minimum wear is assured by forming the wraparound spring, in accordance with the present invention, from a wire with a rectangular cross-section. Each winding of the spring engages in a flat manner with the circumferential surfaces of the hub sections of the drive member and the driven member. By maintaining the space between the hub sections as small as possible, the individual windings of the spring are prevented from entering between the hub sections.
In accordance with another feature of the invention, one end of the wraparound spring is fixed to the driven member and the other end to a releasing device. While the releasing device holds one end of the spring stationary, the other end together with the driven member can turn through a small angle counter to the direction in which the spring is wound. This slight turning action is due, such as at the end of the return stroke, to the mass inertia of the parts participating in the driving operation and it causes an increase in the diameter of the individual winding so that friction-free rotatability of the hub section relative to the spring is achieved.
Another feature of the invention is that the end of the spring connected to the releasing device includes a shifting member which comprises engagement surfaces for a shifting finger on the releasing device. The end of the wraparound spring is bent radially and extends into a recess in the shifting member for affording a non-rotatable connection therebetween. If a single winding clutch is used, only one engagement surface for the releasing device is provided on the periphery of the shifting member. After one revolution of the shifting member, the engagement surfaces runs up against the shifting finger, to stop the shifting member and release the drive member from the driven member.
Preferably, the driven member has stop surfaces for engaging an arresting bolt. There are the same number of stop faces as engagement surfaces on the shifting member. By means of one stop face it is possible after one revolution of the driven member and the resulting drive stroke and return stroke of the drive rod, that the driven member is stopped exactly in a given rotational position. The stop faces and the engagement surfaces can be formed as shoulders in the outer surface of the driven member and the shifting member. It is also possible to provide stop faces or engagement surfaces on a protruding bolt or the like.
In still another feature of the present invention, the shifting finger is connected with the arresting bolt. Such a single part unit is advantageous from a design and functional point of view. To provide a completely wear-free arrangement of the clutch in the disengaged state and also to avoid energy losses, a clearance is established and maintained between the spring windings and the hub sections. This feature is achieved in another arrangement with the driven member forming a locking shoulder for the arresting bolt. The arresting bolt grips the locking shoulder from the rear at the end of the return stroke in a rotational position of the driven member with the spring tightened counter to the wrapping sense so that its windings are increased in diameter. Accordingly, the driving member is freely rotatable. In this rotational position of the driven member fixed by the arresting bolt, the arrangement for converting rotational movement into translational movement of the drive rod, for instance, by a connecting rod, holds the drive rod in a rearmost position.
The actuation of the releasing device can be accomplished in many ways, such as in a pure mechanical arrangement. In a simple dependable problem-free manner the actuation of the releasing device is effected, preferably by a spring or an electromagnet. While a spring accomplishes the engagement of the releasing device into the range of the engagement surfaces, the electromagnet serves for the impulse-like disengagement and thus the releasing or initiation of the installation operation.
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 use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWING
In the drawing:
FIG. 1 is a driving device embodying the present invention, shown mostly in section, and being ready to drive a fastening element;
FIG. 2 is a partial schematic front view of the device shown in FIG. 1 taken from the left side with the front plate removed, at the commencement of the driving stroke;
FIG. 3a is an enlarged sectional view through the driving device taken along the line III--III in FIG. 1 and in position for carrying out the driving operation;
FIG. 3b is a view similar to that illustrated in FIG. 3a but showing the arrangement of the device after the actuation of the driving stroke;
FIG. 4a is an enlarged and simplified sectional view taken along the line IV--IV in FIG. 1 with the device in position for driving; and
FIG. 4b is a view similar to FIG. 4a, however, showing the driving device after the release of the driving stroke.
DETAILED DESCRIPTION OF THE INVENTION
A device for driving fastening elements, such as nails, staples and the like, is shown in FIG. 1 and the device includes a housing 1 with a magazine 2 for supplying the staples 3 to be driven. An electromotor 4 is supported in the housing and includes a fan wheel 5, a rotor shaft 6 and a pinion 7. Pinion 7 meshes with a gear wheel 8 forming part of a drive member 9. Drive member 9 has a hub section 11 and is rotatably supported on an axle 14 by a pair of spaced bearings 12, 13 and the axle is fixed in a motor housing 15. A driven member 17 is rotatably mounted on the axle 14 by an additional bearing 16. An outer bearing 18 positioned in the housing 1 serves for additional support of the driven member 17. The driven member 17 has a hub section 19 having the cylindrically shaped circumferential surface as does the hub section 11.
Bushings 20, 21 and 22 as well as safety rings 23, 24 serve to maintain the spaced support of the bearings 12, 13, 16. A screw 25 retains the overall bearing unit on the axle 14.
The drive member 9 and the driven member 17 can be connected, so that they rotate together, by a clutch in the form of wraparound spring 26. One end 28 of the spring 26 extends into an axial bore 29 in the driven member 17, while the other end 31 is locked in rotatational engagement with a shifting member or ring 32, the shifting member is concentrically arranged on the driven member 17 so that it can rotate on the driven member.
Driven member 17 has a crankpin 33 to which a connecting rod 34 is articulated. The opposite end of the connecting rod 34 from the crankpin has a follower pin 35 extending transversely of it and the follower pin is fixed to a driver rod 36. Follower pin 35 has an end section 37 projecting outwardly from the connecting rod and it is guided in the longitudinal groove 39 in a front plate 38 of housing 1 for carrying out translational movement.
When the driven member rotates, the crankpin revolves, as shown in FIG. 2, in the direction of the arrow and carries the connecting rod 34 with it. The connecting rod converts the rotational movement of the crankpin into the translational movement of the drive rod for its drive stroke and return stroke.
As shown in FIG. 3a, driven member 17 has a stop face 41 on its outer surface in the winding direction of the wraparound spring 26. Further, a blocking shoulder 42 is provided in the region of the stop face 41 and is formed by a radial bore. Stop face 41 adjoins one end of a link track 43 which track extends around the outer surface of the driven member.
As shown in FIG. 4a, switching member or ring 32 has an engagement face 44 facing in the winding direction of the spring 26 and a link track 45 extends around the surface of the switching ring. A slit-shaped recess 46 in the switching ring 32 permits the engagement of a radially bent over end of the wraparound spring 26 formed at an angle 31.
In the position shown in FIGS. 1, 3a and 3b with the device ready to drive a fastening element, the stop face 41 of the driven member and the locking shoulder 42, as illustrated particularly in FIG. 3a, abuts a rod-shaped arresting bolt 47. The arresting bolt 47 is displaceably mounted in a bearing bushing 48, note FIG. 1, fixed on one side of the housing and is maintained in the illustrated engaged position by a spring 51 with an extension piece 49 interposed between them. The engagement face 44 on the switching ring 32 also contacts a switching finger 52, in the form of a transverse beam, which is provided as a single structural unit with the arresting bolt 47. The switching finger 52 and an arm 53 projects outwardly from the finger in the actuating direction and provides the releasing device 54.
To prevent turning of the switching finger 52 and the arresting bolt 47 around the axis of the arresting bolt, arm 53 projects into a guide opening 55 on the side of the housing. This arrangement which prevents turning is required, because in the position ready for inserting a fastening element, the wraparound spring 26 is tightened by about a quarter of a revolution opposite to the winding direction. Accordingly, the switching ring 32 acts by means of its engagement surface 44 with tensile force on the projecting switching finger 52. In this tension position of the spring 26, the inner surface of the windings 27 of the spring are spaced radially from the circumferential surfaces of the hub sections so that a circular gap 56 is formed between the spring and the hub sections.
Disengagement of the switching finger 52 and the arresting bolt 47 is achieved by an electromagnet 58 fixed on a cage 57 provided on a side of the housing. If the electromagnet is switched on, an armature 59 assigned to the extension piece 49 is pulled into the electromagnet opposite to the biasing force of the spring 51.
As shown in FIGS. 3b and 4b, the engagement surface 44 and the stop face 41 are released by the disengagement of the switching finger 52 and the arresting bolt 47 so that the tightened spring 26 slackens partially with a simultaneous reduction in diameter so that the inner surface of the windings 27 bear against the circumferential surfaces of the hub sections 11 and 19. The switching ring 32 turns during the slackening of the spring 26 with respect to the driven member 17 by a quarter of a revolution, as can be seen by comparing FIGS. 4a and 4b.
The inner surface of the spring windings 27 bear with a certain prestress against the circumferential surface of the hub section with a rotating motion being imparted to the hub section by the motor 4 with the hub section carrying the spring 26 due to a frictional locking arrangement, moving in a direction counter to the winding direction. Torque is transmitted by the wraparound spring 26 to the hub section 19 on the driven member 17. The driven member 17 then drives the drive rod 26 by means of the connecting rod 34.
The disengagement of the switching finger 52 and the arresting bolt 47 takes place in the manner of an impulse whereby directly following the releasing impulse caused by the electromagnet 58, the electromagnet is switched off and the switching finger 52 and the arresting bolt 47 move against the connecting link tracks 43, 45 due to the action of the spring 51. The wraparound spring 26 fixed on the rotating hub sections 11, 19 also rotate the switching ring 32. After approximately three-quarters of a revolution of the switching ring 32, its engagement surface 44 moves against the switching finger 52 so that the rotating motion of the spring 26 stops. The driven member 17 and the parts connected to it continue to run in the direction of rotation because of their mass inertia, until after approximately a further one-quarter of a turn, the stop face 41 trailing the engagement face 44 contacts the arresting bolt 47 whereby the rotational movement of the driven member 17 is discontinued. By further rotation of the driven member relative to the switching ring 32, the spring 26 with its ends fixed to these parts, expands in diameter of the windings to the arrangement displayed in FIGS. 1, 4a so that a circular gap 56 is formed between the spring windings and the hub sections 11, 19. Thus, the rotational connection between the driving member and the driven member is broken.
To prevent the existing tensile force in the wraparound spring 26 from causing a reverse rotation of the driving member 17, the arresting bolt is biased by the spring 51 in front of the blocking shoulder 42 directly after the engagement surface 41 runs into contact with the bolt. Accordingly, the device is returned into position ready to install another fastening element with the drive rod 36 assuming the rearmost position. A staple 3 provided for the next insertion operation can be moved out of the magazine channel 2 into the path of the driving rod 36. As described above, other driving steps can be actuated by a trigger 61. The trigger 61 acts on an electric impulse switch 62 shown schematically and the switch feeds current supplied via a lead wire 63 from an energy source as an impluse to the electromagent 58 for activation over the connecting wires 64.
While specific embodiments of the invention have been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. | A device for driving nails, staples and similar fastening elements includes an electromotor for rotating a driving member. The rotation of the driving member is transferred to a driven member which, in turn, converts the rotational movement into translational movement. The rotational movement from the driving member to the driven member is effected for a limited time period by a clutch so that a drive stroke and a return stroke are carried out. A releasing device actuates the clutch. | 1 |
TECHNICAL FIELD
Use of nodular cast iron instead of cast steel in mechanical engineering for production engineering and economic reasons. Technology for joining nodular cast iron/steel for composite components.
The invention relates to the further development and improvement of the types of joint, characterized by poor weldability per se of nodular cast iron, with iron materials of lower carbon content.
In particular it relates to a method for joining nodular cast iron to steel by means of fusion welding.
PRIOR ART
Nodular cast iron/steel welded joints are particularly difficult to produce since carburization takes place on the low-carbon side with carbide formation which results in the formation of a brittle hard zone which cannot be eliminated by annealing.
Inter alia, it has already been proposed to accomplish the nodular cast iron/steel joint by one of the following methods:
1. Decarburization of the nodular cast iron surface to be joined to a depth of approx. 2 mm. Welding with iron electrodes.
This requires annealing in a decarburizing medium lasting up to 48 h and temperatures of 900° to 950° C. Such annealings are expansive and there is the danger of considerable warping of the nodular cast iron parts.
2. Welding with Fe/Ni electrodes containing 70% by weight of Ni and 30% by weight of Fe (cf. UTP-Schweissmaterial AG, CH-4310 Rheinfelden; G. Korfeld, "Zusatze zum Schwwissen von Eisengusswerkstucken" (Additives for welding cast iron workpieces), Giesserei 69, 1982, pages 112-119).
This method is only of limited applicability, mostly for repair work. The welded material is susceptible to thermal cracks and has only low mechanical strength.
3. Casting of the components to be joined (pipe, rod) of steel into the nodular cast iron part. The anchoring is guaranteed by irregularities (holes, bulges, knobs etc.) in the steel component, and therefore is predominantly of a mechanical and not a metallugical nature. Since the brittle edge zones in the steel component inecitably lead to large-area cracks, sealed joining cannot be achieved in this manner.
From the above it is evident that there is a lack of suitable methods for welding components made of nodular cast iron to those made of steel, it being necessary for the welding zone to have at least the mechanical properties of the nodular cast iron.
DESCRIPTION OF THE INVENTION
The invention is based on the object of providing a method for joining nodular cast iron to steel by means of fusion welding in which brittle hard zones leading to cracks and leaks are avoided. It should be possible t carry out the method with the simple means and economically.
This object is achieved by a method mentioned in the introduction wherein an iron alloy with a silicon content of 2 to 4% by weight is used as filler to which additionally seeding substances are added to precipitate the carbon in globular form in the welding zone.
METHOD OF EMBODYING THE INVENTION
The invention is described on the basis of the following exemplary embodiments explained in more detail by figures.
In these:
FIG. 1 shows a cross-section through a joint between nodular cast iron and steel by means of multi-layer direct welding with alloyed filler,
FIG. 2 shows a cross-section through a joint between nodular cast iron and steel by means of multi-layer build-up welding with alloyed filler and weld joining with unalloyed filler,
FIG. 3 shows a cross-section through a joint between nodular cast iron and steel by means of multi-layer build-up welding with alloyed and subsequent unalloyed filler and weld joining with unalloyed filler,
FIG. 4 shows a diagrammatic metallographic cross-section through the weld material of a build-up weld with alloyed and unalloyed filler (microstructure).
FIG. 1 shows a diagrammatic representation (cross-section) of a joint between nodular cast iron and steel by means of a multi-layer direct welding with alloyed filler. For the sake of simplicity of a plain butt weld is drawn here. Of course, U welds, V welds or fillet welds etc. can be executed in this manner. 1 is a plate made of nodular cast iron with the included globular graphite 2. 3 is a plate made of steel (low-carbon iron alloy). 4 represents the weld joining with Si-alloyed filler which as a rule is executed in multi-layer form. The relatively fine-grain globular graphite precipitations are indicated by black spots.
FIG. 2 diagrammatically represents a cross-section through a joint between nodular cast iron and steel by means of a multilayer build-up welding with alloyed filler and a weld joining with unalloyed filler. The plate made of nodular cast iron 1 with the globular graphite 2 has a built-up welding with Si-alloyed filler. 5 corresponds to a 1st layer and 6 to a 2nd layer of this build-up welding. The actual weld joining 7 is executed with unalloyed filler. 3 is the plate made of steel.
FIG. 3 shows diagrammatically a cross-section through a joint between nodular cast iron and steel by means of a multi-layer build-up welding consisting of welding material with alloyed and subsequent unalloyed filler and a weld joining with unalloyed filler. The reference numerals 1, 2, 3, 5, 6 and 7 correspond precisely to those in FIG. 2. In addition to the build-up welding 5, 6 with alloyed filler, a further two-layer build-up welding with unalloyed filler is also present. 8 corresponds to a 1st layer and 9 to a 2nd layer of this build-up welding.
FIG. 4 represents a diagrammatic metallographic cros-section through the welding material of a build-up welding with alloyed and unalloyed filler. The representation shows the zone-by-zone build-up of the microstructure. 2 is the globular graphite of the thermally unaltered nodular cast iron in the initial condition. 10 represents the globular graphite of the recooled solidified weld metal zone of the nodular cast iron. 11 is the globular graphite of the 1st layer of the build-up welding with Si-alloyed filler, while 12 shows the corresponding graphite of the 2nd layer with the same filler. A is the zone of the unaltered nodular cast iron. B represents the fused material of the weld metal zone of the nodular cast iron. C is the welding material of the 1st layer of the build-up welding with Si-alloyed filler. D corresponds to the welding material of the 2nd layer of the build-up welding with the same filler. E is the welding material of the 1st layer of the build-up welding and F is that of the 2nd layer of the build-up welding with unalloyed filler. In other respects, the Figure is self-explanatory. Attention should further be drawn to the fact that no fairly large, hard and brittle carbide precipitations occur in any of the zones. The matrices of all the zones are of a predominantly ferritic or ferritic-perlitic nature.
EXEMPLARY EMBODIMENT I
See FIG. 1!
Plates made of nodular cast iron 1 and low-carbon steel 3 were joined together directly by art welding with Si-alloyed filler. The plates had the following dimensions:
Width=100 mm
Length=200 mm
Thickness=20 mm
The nodular cast iron had the following composition:
C=3.2% by weight,
Si=1.9% by weight,
Mn=0.6% by weight,
Ni=1.4% by weight,
Mg=0.06% by weight,
Fe+impurities=remainder
The steel 3 with the commercial designation St 37 according to DIN 17 100 had the following composition:
C:=0.2% by weight,
P:=0.05% by weight,
S:=0.05% by weight,
Fe+Si+Mn=remainder
The chemical composition of the welding electrode and the corresponding electrode coating was matched in a manner such that a welding material of the following compositin was produced in the arc welding:
C=0.08% by weight,
Mn=0.45% by weight,
Si=3.0% by weight,
Al=0.0075% by weight,
Mo=0.55% by weight,
Ce=0.0013% by weight,
Mg=0.0006% by weight,
Zr=0.04% by weight,
S=0.004% by weight,
P=0.02% by weight,
Fe=remainder
The plates to be welded together were preheated to approx. 400° C. before the welding operation and the weld region was held at 350° to 500° C. After completion of the welded seam, the workpiece was immediately heated up to an annealing temperature of 700° to 710° C. without being cooled down and this temperature was maintained for 6 h. In this process any carbides formed in the weld zone were converted into temper carbon (see also FIG. 4!). The workpiece was then allowed to cool in the furnace.
Test pieces were then machined from the workpiece. The tensile test piece and the edge-bend test piece revealed that the fracture always occurred outside the welding seam or the transition zone, vis. in the unaltered structure of the nodular cast iron. Apparent yield points of approx. 300 MPa, ultimate tensile strengths of approx. 400 MPa and bend angles of up to 35° were reached.
EXEMPLARY EMBODIMENT II
Compare FIG. 1!
A steel pipe was welded as an addition onto a pump housing of nodular cast iron. The latter had the following dimensions:
Outside diameter=48 mm
Inside diameter=40 mm
wall thickness=4 mm
The nodular cast iron, which had the commercial designation CCC 40 had the following composition:
C=2.9% by weight,
Si=2.7% by weight,
Mn=0.5% by weight,
P=0.08% by weight,
S=0.015% by weight,
Fe=remainder
The steel pipe material, which had the commercial designation St.35.8 in accordance with DIN 17 175 had the following composition:
C=0.17% by weight,
Si=0.1 to 0.35% by weight,
Mn=0.4 to 0.8% by weight,
S=0.04% by weight
The workpieces were first preheated to 380° to 400° C. and then the tube was welded onto the pump housing with a normal fillet weld with an alloyed welding electrode of the composition as specified in Example 1. The workpiece was then heated immediately, without cooling, to a temperature of 720° to 750° C. and anneated at this temperature for 4 h.
The pipe, which was sectioned in the longitudinal direction, was subjected to a bend test. It was possible to bend both the concave and also the convex half of the pipe connecting piece (viewed in the bending direction) satisfactorily through 90° without incipient cracking.
EXEMPLARY EMBODIMENT III
See FIG. 2!
Plates made of nodular cast iron and low-carbon steel 3 were assembled into a workpiece by build-up welding 5, 6 and weld joining (7) by the arc welding process. The dimensions of the plates correspond to those of Example I. The nodular cast iron with the commercial designation GGG 40 had the composition as specified in Example II, and the steel with the commercial designation St 37 that specified in Example I.
First two layers 5, 6 of welding material made of Si-alloyed filler each 3 mm thick as specified in the composition in Example I were applied to an end face of the nodular cast iron plate 1. The nodular cast iron was preliminarily preheated to a temperature of approx. 375° C. Then a multi-layer weld joining 7 was made between the nodular cast iron 1 prepared in this manner by build-up welding and the steel 3 by means of an unalloyed electrode. The welding electrode had the following composition:
C=0.03 to 0.04% by weight,
Si=0.3% by weight,
Mn=0.6% by weight,
Fe+impurities=remainder
Finally, the workpiece was annealed for 5 h at a temperature of 730° C. without being cooled down.
The samples revealed the following pattern:
Apparent yield point:=approx. 320 MPa
Ultimate tensile strength:=approx. 420 MPa
Bend angle:=approx. 401° C.
EXEMPLARY EMBODIMENT IV
Along the lines of Example III, but with a different, partially reversed lay sequence, a steel pipe with the commercial designation St.35.8 was "embedded" in a steam turbine cylinder made of nodular cast iron with the commercial designation GGG 40. In this process, the tube to be embedded was preheated to 200° C. at the part to be joined to the nodular cast iron and provided with a 2 mm thick layer of build-up welding of Si-alloyed filler according to the specification specified in Example I over a width of 10 mm. After cooling down, the pipe was inserted into the casting mould in a manner such that its end projected into the space to be filled with the melt and had the above nodular cast iron material cast around it. The Si-alloyed welding material had the effect that on cooling down, the carbon in the transition zone was not present as iron/carbide phase, but the temper carbon is precipitated. This pevented cracks being produced in the transition zone on complete cooling of the workpiece or subsequently in operation
EXEMPLARY EMBODIMENT V
Compare FIGS. 3 and 4!
The following preparatory operations were executed on a casting made of nodular cast iron 1 of the composition specified in Example I after preheating to 375° C.:
two-layer build-up welding 5, 6, each layer 3 mm thick, with Si-alloyed filler of the composition specified in Example I.
two-layer build-up welding 8, 9, each layer 2.5 mm thick, with unalloyed filler of the composition specified in Example III.
annealing of the workpiece for 6 h at a temperature of 740° C.
Slow cooling of the workpiece in the furnace.
In this process, the uppermost layer of the buildup welding with unalloyed filler had a C content which was only approx. 0.2 to 0.4% by weight.
The workpiece was now transferred to the machine shop. There components 3 made of St.37 were welded on with an unalloyed iron electrode at the build-up welding points after a preheating to 250° C. A subsequent additional heat treatment was unnecessary.
Break test samples taken from the bonding zones revealed that the material always underwent incipient cracking outside the welding material and the transition zones. Values of the apparent yield point of an average 330 MPa and those of the ultimate tensile strength of an average 440 MPa were achieved. Bending angles in welded-on rods and pipes yielded values of 60° to 90° without break.
The method is not limited to the exemplary embodiments. In principle, high-carbon iron materials containing the carbon in elementary form can be joined in this manner to low-carbon iron materials.
An iron alloy containing 2 to 4% by weight of silicon is advantageously used as filler for the direct weld joining or the build-up welding on the high-carbon material. The filler should additionally contain in the core wire and/or the coating seeding materials which guarantee the precipitation of carbon in globular form in the welding zone (actual welding seam and traisition zones). A welding electrode for arc welding is preferably used as filler.
The method may be executed as a direct joining method with Si-alloyed filler or as a method with one or several build-up weldings (2 to 3 layers) with alloyed and unalloyed filler. In the latter cases, the actual weld joining may be carried out with a conventional unalloyed filler. The build-up welding can be carried out in the foundry, it being possible to omit preparations such as mechanical machining or etching. The workpieces joined by the fusion welding are preferably annealed at 700 to 750° C. for 1/2 to 6 h. This applies also to substeps, for example after the build-up welding. Under these circumstances, carbides are reliably converted into globular temper carbon. Expediently, the workpieces are preheated to a temperature of 250° to 500° C. before the fusion welding.
Advantageously, the filler used for welding may have the following composition limits:
C=0.01-0.12% by weight,
Mn=0.2=-1.5% by weight.
Si=1=-4% by weight,
Al=0.005-0.1% by weight,
Mo=0.2=-0.7% by weight,
Ce=0.0001-0.02% by weight,
Mg=0.0001-0.01% by weight,
Zr=0.01=-0.7% by weight,
S=0.0006% by weight max.,
P=0.01% by weight max.,
Fe=remainder
List of Designations
1: Nodular cast iron
2: Globular graphite of nodular cast iron
3: Steel
4: Multi-layer weld joining with Si-alloyed filler
5: 1st layer of build-up welding with Si-alloyed filler
6: 2nd layer of build-up welding with Si-alloyed filler
7: Weld joining with unalloyed filler
8: 1st layer of build-up welding with unalloyed filler
9: 2nd layer of build-up welding with unalloyed filler
10: Globular graphite of the weld metal zone of the nodular cast iron
11: Globular graphite of the 1st layer of the build-up welding with Si-alloyed filler
12: Globular graphite of the 2nd layer of the build-up welding with Si-alloyed filler
A: Unaltered nodular cast iron
B: Solidified material of the weld metal zone of the nodular cast iron
C: Welding material of 1st layer of build-up welding with Si-alloyed filler
D. Welding material of 2nd layer of build-up welding with Si-alloyed filler
E. Welding material of 1st layer of build-up welding with unalloyed filler
F. Welding material of 2nd layer of build-up welding with unalloyed filler | A component made of nodular cast iron is joined to a component made of steel by means of fusion welding, a Fe alloy containing 2 to 4% by weight of silicon and seeding materials for the purpose of globular carbon precipitation in the welding zone being used as filler. Advantageously, the nodular cast iron component is provided beforehand with a build-up welding with Si-alloyed filler or with an unalloyed filler now alloyed with such a Si-alloyed filler, whereupon the weld joining to the steel component can be carried out with conventional iron electrodes.
Preferred Si-alloyed filler:
C=0.01-0.12% by weight,
Mn=0.2-1.5% by weight,
Si=1-4% by weight,
Al=0.005-0.1% by weight,
Mo=0.2-0.7% by weight,
Ce=0.0001-0.02% by weight,
Mg=0.0001-0.01% by weight,
Zr=0.01-0.7% by weight,
S=0.006% by weight max.,
P=0.01% by weight max.,
Fe=remainder | 1 |
This is a divisional Ser. No. 07/768,167 filed on Sep. 30, 1991, now U.S. Pat. No. 5,180,401.
BACKGROUND OF THE INVENTION
This invention relates to blankets. More particularly it relates to printed woven blankets.
Various types of blankets are sold having designs or patterns on one or both sides. These blankets range in quality from low cost nonwoven blankets, which are printed on one or both sides, to high cost Jacquard woven blankets which are made with individually dyed yarns which are woven together utilizing sophisticated numerical controls to form patterns or designs which are equally visible on both sides of the blanket. Because of the fact that the yarn in each color group must be independently dyed, because the manufacturer must utilize expensive numerically controlled Jacquard looms in order to complete the manufacture, and because of the labor involved in setup and the operation of the Jacquard looms, Jacquard woven blankets are very expensive, often costing the consumer more than $70.
Nonwoven blankets are very inexpensive, often costing the consumer less than $5. However, nonwoven blankets tend to be stiff and do not have the feel or hand of a woven blanket.
Standard woven blankets generally cost the consumer slightly more than $15. In order to produce a woven blanket with colorful patterns or designs, which has a good hand, without using the expensive Jacquard weaving process, standard woven blankets have been subjected to dyes, i.e. printing, after weaving. However unless the blanket is printed on both sides, i.e. the blanket is run through two printing and finishing cycles involving numerous steps, it has been found that, while the printed side of the blanket will show vivid colors and definition, the unprinted side will show only a fraction of the color and definition of the printed side.
Printed woven blankets have been manufactured by applying dye to one side of the blanket through a print screen utilizing an elongated blade or squeegee like device which forms a wave of the dye inside the print screen. The dye flows through the screen onto the surface of the blanket fabric. Penetration into the fabric is not substantial. Pigment, fiber reactive, and cationic dyes have been used depending on the type of fabric, i.e. acrylic, cotton, etc. After the dye is applied, the blankets are subjected to various processes including drying, steaming, scouring and napping. While the printed side of the blanket exhibited strong coloration and definition, the unprinted side did not exhibit nearly as strong a coloration and furthermore the designs on the unprinted side lacked definition. Thus the purchaser could readily distinguish one side of the blanket from the other. Heretofore blanket manufacturers have not been able to produce a printed blanket which has the appearance of a Jacquard woven blanket.
OBJECTS OF THE INVENTION
It is therefore one object of this invention to provide an improved printed woven blanket.
It is another object to provide an improved printed woven blanket which is printed on only one side but gives the appearance of having been printed on both sides.
It is another object to provide a printed woven blanket which is inexpensive to manufacture but has the appearance of a much more expensive Jacquard manufactured blanket.
It is another object of the invention to provide an improved method for manufacturing printed woven blankets.
SUMMARY OF THE INVENTION
In accordance with one form of this invention, there is provided a woven blanket including a fabric constructed of woven yarn. The fabric has a first side and a second side with at least a portion of the first side having been printed with a dye. A visible pattern is formed on the first side and the second side as a result of the first side having been printed, with the visible characteristics of the pattern on the second side being substantially the same in intensity and resolution as the pattern on the first side. It is preferred that the blanket not be printed on the second side.
Preferably the blanket is made of an acrylic yarn and the dye utilized is a cationic dye.
In accordance with another form of this invention, there is provided a method for producing the above-described printed woven blanket. Only one side of a woven blanket is printed with a dye. The printing is preferably accomplished by applying the dye through a print screen utilizing a roller which places downward pressure on the dye which forces the dye into the blanket yarn. Preferably the dye is completely dried after printing. Moisture, preferably steam, is then applied to the printed blanket to set the dye. At least the one side of the blanket is then napped.
Preferably the pressure applied on the roller may be varied by the operator so that the amount of dye put into the blanket and thus the intensity of color may be controlled. It is also preferred that the pressure be controlled by the use of magnetic force on the roller. By using the above-described method it is believed that the dye will penetrate at least to a depth of 40% into the yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention is set forth in the appended claims. The invention itself however together with further objects and advantages thereof may be better understood in reference to the accompanying drawings in which:
FIG. 1 is a plan view of one side of the blanket of the subject invention.
FIG. 2 is a plan view of the other side of the blanket of FIG. 1.
FIG. 3 is a block diagram illustrating the steps in the process utilized to manufacture the blanket shown in FIGS. 1 and 2 in accordance with the subject invention.
FIG. 4 is a pictorial view illustrating a portion of the printer with pressurized roller of FIG. 3 being utilized to print the side of the blanket shown in FIG. 1.
FIG. 5 is a side elevational view showing a portion of the apparatus of FIG. 4.
FIG. 6 is a sectional view of the blanket of FIG. 1 taken through section lines 6--6.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to FIGS. 1 through 6, there is a provided woven blanket 10 having two sides, namely side 12 as shown in FIG. 1 and side 14 as shown in FIG. 2. Both sides of blanket 10 exhibit printed patterns 16 and 18, although only one side, namely side 12, has been printed by direct exposure to a dye. However, by utilizing the process described below, one cannot visually detect a substantial difference in color intensity or resolution between the dyed side 12 and the undyed side 14. The patterns 16 and 18 are simplified and are for illustration purposes only. Preferably the entire side 12 is exposed to several dyes of various colors.
Referring now more particularly to FIGS. 3 through 6, there is a provided a method for the manufacture of the blanket shown in FIGS. 1 and 2. In the first step of the process, illustrated as block 19 in FIG. 3, the unprinted woven blanket fabric 20 which is preferably made of white acrylic yarn is printed with a dye, which preferably is a cationic dye. The preferred printing apparatus is an MBK printer Model No. SDM2020 which is commercially, available from MBK Maschinenbau Krefersfelden GmbH. The printer includes a plurality of rotatable cylindrical print screens, one of which is illustrated in FIG. 4 as print screen 22. Print screen 22 includes template openings 24 which, together with dye 28, form the printed pattern 16 on the blanket. The printer normally includes additional cylindrical print screens with various patterns to be used with different colored dyes to print different colored patterns on the blanket. However for simplicity's sake the additional screens are not shown.
Inside the cylindrical print screen 22 a rotating floating cylindrical roller 26 is provided. The roller is utilized to force dye 28, which is received inside the screen 22, through the template openings 24, and into the fabric 20. Roller 26 applies a downward pressure on dye 28, the print screen 22 and thus the fabric. The downward pressure is caused by magnet 30 which interacts with the roller. Preferably the force of magnet 30 is made variable by means of a device such as variable resistor 32 so that the amount of pressure of the roller and thus the printed color intensity is controllable. By utilizing this cylindrical roller 28 with downward pressure, a substantials depth of penetration of the dye into the fabric will result as indicated by dye penetration 33. This dye penetration 33 is also illustrated in referenced to FIG. 6 which shows a cross section of the weft yarns 25 of finished blanket 10. It is believed that a dye penetration into the yarns 25 of greater than 40% may be achieved for normal denier blanket yarns. The roller should be made out of metal such as iron or steel which is attracted by and thus controlled by magnet 30.
The freshly printed fabric 34, which will eventually form blanket 10 when cut, then moves to the dryer stage 35. It is preferred that the dryer completely dries the dye so that it will not cause spotting of the fabric 34 when that fabric is moved to the next stage in the process. A preferred dryer is a Tubular Jet Aztec dryer commercially available from the Aztec Machinery Company. The Aztec dryer provides for multiple passes of the blanket fabric through the dryer so as to ensure complete drying of the dye. The dried fabric 34 is then run through a steamer 37 which is used to "set the dye," that is, the steam causes the cationic dye to penetrate into the acrylic fibers in the yarn of the fabric. An acceptable steamer is a Continuous Ager steamer commercially available from the Morrison Company. The fabric is then scoured as indicated by step 39 to remove unwanted chemicals as well as excess dye. An acceptable scourer is an Open Width scourer commercially available from the Morrison Company. The fabric is then placed in another dryer 41. An acceptable dryer for this final drying step is an Artos Tentu Flow Through dryer, commercially available from the Artos Company. The fabric 34 is then pile napped both on side 12 and side 14. An acceptable pile napper is a Woonsocket Thirty-Six Roll, Double Acting napper, Model No. 1036 commercially available from United Textile Machinery Corp. The fabric then undergoes felting on a single acting napper. An acceptable napper is a Franz-Muller single acting napper commercially available from BASF Corporation. The construction of dryers, steamers, scourers and nappers is well known to those skilled in the blanket art and therefore detailed descriptions are not necessary.
Nappers are primarily utilized in the blanket industry to raise the fibers thereby imparting a soft hand to the blanket. However, it was found that since the dye obtained such a deep penetration 33 into the fabric by the printing step and such penetration was set by the steam step, the napper will also "pull through" the image which has been printed on side 12 of the blanket to side 14 to the extent that an observer cannot tell any subtracted difference in the intensity and sharpness of the images on one side 12 and side 14 of the blanket. That is, blanket 10 appears to have been printed both on side 12 and 14. Furthermore it has been found that better results are achieved when more napping pressure is used on the dyed side 12 than the undyed side 14. The napping step also softens the appearance of the patterns 16 and 18 on both sides of the blanket so that the images are not too sharp in addition to imparting a softer hand to the blanket.
After the napping step, the fabric 34 is sprayed with ethylene carbonate (Permanap) and a softener as illustrated by step 45. The fabric is then cut to the desired size of the blanket which normally is 80"×90", and the blanket is ready to be packaged and sold.
The preferred dyes used to print the blankets are referred to as cationic dyes. Cationic dyes were chosen because of their ability to penetrate into certain synthetic fibers, such as acrylic, and because they more readily penetrate into synthetic fibers than pigments. Acceptable cationic dyes are commercially available from the Ciba Giegy Company. For blankets made of cotton, fiber reactive dyes are preferred.
A blanket, which was manufactured as set forth above, has been tested, along with a prior art blanket, utilizing an ACS optical tester. Several measurements of reflected light were taken at corresponding pattern positions on each side. Both blankets were made with acrylic fibers. Each was dyed on one side only using cationic dyes. The prior art blanket was made utilizing printers having a squeegee type dye applicator. The table set forth below illustrates the result.
______________________________________PERCENT REDUCTION OF REFLECTED LIGHTFROM PRINTED SIDE TO UNPRINTED SIDE Prior Art Acrylic Blanket of Acrylic Blanket the Subject Invention______________________________________Position A 27.44% 13.4%Position B 26.48% 8.97%Position C 33.84% 10.36%______________________________________
There was much less reduction in reflected light for the blanket of the subject invention than the prior art blanket.
Thus a printed woven blanket is provided which appears to have been printed on both sides while in reality it was printed only on one side, and which has the look and feel of a more expensive Jacquard produced blanket.
From the foregoing description of the preferred embodiment of the invention it will be apparent that many modifications may be made therein without departing from the true spirit and scope of the invention. | A printed woven blanket is provided which is printed on only one side but has the appearance of having been printed on both sides. A cationic dye is applied to one side of the blanket utilizing a roller which forces the dye into the fabric forming a printed pattern. The printed blanket is dried and then steamed to set the dye. The blanket is napped which further enhances the appearance of the side which is not printed. | 3 |
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The present invention relates to a photoconductor for electrophotography and more particularly to an organic photoconductor suitable for an electrophotographic apparatus adopting the contact charging system.
DESCRIPTION OF THE PRIOR ART
The image formation of an electrophotographic system discovered by Carlson comprises the steps of charging the surface of a photoconductor for electrophotography (hereinafter to be referred to as a photoconductor) in the dark, forming the latent electrostatic image by exposing the surface of the charged photoconductor to light, developing the formed latent electrostatic image with a toner, transferring the developed toner image to a support such a paper and fixing the toner image on the support. After the image transfer, the photoconductor is subjected to the cleaning process such as the removal of the remaining toner and residual charge and ready to use repeatedly.
In recent years, a photoconductor in which use is made of an organic photoconductive material has been developed and been put into practical use. At present, an organic photoconductor of a functionally separated type has been further developed as a main acceptable product. A photoconductive layer of this type comprises a charge generating layer containing a charge generating agent for generating an electric charge upon absorbing exposure light in the presence of an electric field and a charge transporting layer formed on the charge generating layer and containing mainly a charge transporting agent for transporting the electric charge generated.
In improving a performance required of the charge generating agent, it is required that an absorption coefficient of exposure light is high, a charge generating efficiency upon absorbing exposure light is high and the charge generated moves rapidly. Therefore, the organic pigment is mainly used. The charge generating layer is formed by subliming the organic pigment as the charge generating agent on a conductive substrate or on an undercoat layer formed on the conductive substrate if necessary. The charge generating layer is also formed by coating a coating solution, in which the organic pigment is dispersed or dissolved into a carrier medium together with a binder if necessary, onto the conductive substrate or the undercoat layer formed on the conductive substrate and drying the coating solution. At present, the latter method is largely used in terms of high productivity and operativity. It is required that the organic pigment is easily dispersed into the coating solution and the coating solution is stable so as not to occur a coalescence of the organic pigment during coating or storage. For this reason, it is necessary that the organic pigment usable for the charge generating agent is a particle as fine as possible and the stability of dispersion is improved. To fine the particles of the organic pigment is effective in increasing an absorption coefficient of light. Moreover, the organic pigment usable as the charge generating agent is generally a p-type semiconductor. A hole moves rapidly and an electron is difficult to move among the charges generated in the organic pigment.
Therefore, it is required that the charge generating layer is as thin as possible so as not to be an obstacle to the movement of electrons. For this reason, it is indispensable for the particle of the organic pigment to be as fine as possible. At present, the particle of the organic pigment of the submicron order is used.
On the other hand, a corona discharge such as corotron or scorotron has conventionally played a main role in charging the surface of the photoconductor. However, this charging system produces a product such as ozone or NOx by the corona discharge, deteriorates the photoconductor and leads to environmental destruction. Moreover, since a corona discharge wire and the casing electrode surrounding semicylindrically the wire are provided with a distance from the photoconductor such that they do not contact the latter, there is a problem that the miniaturization of the apparatus is restricted.
For the purpose of solving the problems as mentioned above, a charging system for bringing the conductive material into direct contact with the surface of the photoconductor was devised in place of the charging system by corona discharge. This system is disclosed in Japanese Patent Application Laying-open Nos. 178267/1982, 104351/1981 and 40566/1983. The conductive material may be adopted in the form of a brush, a roller, a plate or a sheet in this charging system. The surface of the photoconductor is charged by bringing it into direct contact with the conductive material and by applying a high voltage to the conductive material.
Since the apparatus of this system can be miniaturized without producing ozone and/or NOx, this does not also lead to the deterioration of the photoconductor or environmental destruction.
The contact charging system has various advantages as mentioned above, but this system has problems as follows:
1) It is difficult to charge over the whole surface of the photoconductor with a uniform surface electric potential.
2) The qualities of image in repeated use of the photoconductor for a long period of time become gradually poor.
3) Defects such as black dots, white spots and blurring happen.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a photoconductor for electrophotography without producing a non-uniformity of image is an electrophotographic apparatus adopting the contact charging system and without producing image defects in repeated use for a long period of time.
In the first aspect of the present invention, a photoconductor for electrophotography comprises:
a conductive substrate;
a charge generating layer formed on the conductive substrate and containing the particles of an organic pigment as a charge generating agent and a binder; and
a charge transporting layer formed on the charge generating layer;
in which the largest value of major axes of the particles is not more than 1000 nm, the smallest value of minor axes of the particles is not less than 10 nm and the ratio of the largest value of major axes to the smallest value of minor axes is not more than 3.
In the second aspect of the present invention, a photoconductor for electrophotography comprises:
a conductive substrate;
a charge transporting layer formed on the conductive substrate; and
a charge generating layer formed on the charge transporting layer and containing the particles of an organic pigment as a charge generating agent and a binder;
in which the largest value of major axes of the particles is not more than 1000 nm, the smallest value of minor axes of the particles is not less than 10 nm and the ratio of the largest value of major axes to the smallest value of minor axes is not more than 3.
The charge generating agent may be a phthalocyanine-type pigment.
The charge generating agent may be 4, 10-dibromoanthanthrone.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are schematic cross-sectional views of photoconductors according to the present invention, respectively.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a laminate type photoconductor. A laminated photosensitive layer 1A is provided on an electroconductive substrate 1, a lower layer of the laminate is a charge generating layer 2 including a charge generating substance 3 as a main component and a binder 4, and an upper one is a charge transporting layer 6 containing a charge transporting substance.
FIG. 2 shows another laminate type photoconductor having a photosensitive layer 2A of the structure in reverse to that of FIG. 1. A laminated photosensitive layer 2A is provided on an electroconductive substrate 1, a lower layer of the laminate is a charge transporting layer 6 including a charge transporting substance and an upper one is the charge generating layer 2 including a charge generating substance 3 and a binder 4. In this case, a covering layer 7 may generally be further provided as shown in FIG. 2 to protect the charge generating layer 2.
A photoconductor as shown in FIG. 1 can be prepared by depositing a charge generating substance on an electroconductive substrate by means of vacuum evaporation or applying and drying a dispersion of a particulate charge generating substance in a solvent and/or a resin binder on an electroconductive substrate, followed by applying a solution containing a charge transporting substance and a resin binder on the resulting layer and drying.
A photoconductor as shown in FIG. 2 can be prepared by applying and drying a solution containing a charge transporting substance and a binder on an electroconductive substrate, and depositing a charge generating substance on the resulting coating layer by means of vacuum evaporation or coating and drying a dispersion of a particulate charge generating substance in a solvent and/or a binder on the coating layer, followed by formation of a covering layer.
The covering layer 7 has a function of receiving and retaining an electric charge generated by corona discharge in the dark and a capability of transmitting light to which the charge generating layer should respond. It is necessary that the covering layer transmits light upon exposure of the photoconductor and allows the light to reach the charge generating layer, and then undergoes the injection of an electric charge generated in the charge generating layer to neutralize and erases a surface electric charge. Materials usable in the covering layer include organic insulating film-forming materials such as polyesters and polyamides. Such organic materials may also be used in mixture with an inorganic material such as a glass resin or SiO 2 , or a material for lowering electric resistance such as a metal or a metallic oxide. Materials usable in the covering layer are not limited to organic insulating materials for film-forming, and further include inorganic materials such as SiO 2 , metals, and metallic oxides, which may be formed into a covering layer by an appropriate method such as vacuum evaporation and deposition, or sputtering. From the viewpoint of the aforementioned description, it is desirable that the material to be used in the covering layer be as transparent as possible in the wavelength range in which the charge generating substance attains maximum light absorption.
The conductive substrate has a function for the support of the charge generating layer and the charge transporting layer together with a function for the electrode of the photoconductor. This conductive substrate may be used in the form of a cylinder, a plate or a film. The material of the conductive substrate for use can be a material such as aluminum, aluminum alloy, stainless steel or a conductive plastic.
The surface of the conductive substrate may be coated by a conductive paint in order to flatten the surface if necessary and by an low electric resistance resin such as a solvent-soluble polyamide resin, polyvinyl alcohol, casein, a cellulose derivative, a vinylchloride resin, an acryl resin, a polyether resin in order to give a blocking property. The conductive substrate made of aluminum or aluminum alloy may be also subjected to anodized aluminum treatment in place of the coating of the resin.
An organic pigment usable as the charge generating agent contained in the charge generating layer which is formed on the conductive substrate or on the undercoat layer formed on the conductive substrate includes a phthalocyanine such as metal-free phthalocyanine of an α-type and a β-type, copper phthalocyanine of an α-type, a β-type and an ε-type, chloroaluminum phthalocyanine, vanadyl phthalocyanine or titoxy phthalocyanine, a polycyclic quinone such as 3, 9-dibromoanthanthorone, a quinacridone pigment, a perylene pigment or a perynone pigment.
A coating solution prepared by dispersing the organic pigment into a binder and a solvent depending on the type of the organic pigment is applied by the immersion coating, the spray coating, the blade coating or the screen coating onto the conductive substrate and by drying to form the charge generating layer. It is preferable that the ratio of the organic pigment to the binder is within the range from 0.5 part by weight to 20 parts by weight of the organic pigment with respect to 1 part by weight of the binder. Moreover, the charge generating layer is generally formed with a thickness from 0.1 μm to 2.0 μm.
According to the present invention, the photoconductor suitable for the electrophotographic apparatus of the contact charging system is obtained by adequately selecting the size and shape of the particles of the organic pigment contained in the charge generating layer. However, since the organic pigment as mentioned above becomes easily a needle crystal, it is required that the organic pigment is ground and dispersed in preparing the coating solution for the charge generating layer in order to obtain the particle of an adequate size and shape.
It is not necessary to use a particularly new grinder and a dispersion mixer in grinding and dispersing the organic pigment. Since an apparatus such as a ball mill, a sand mill or a jet mill has been conventionally used, it is required that the sizes and shapes of the particles of the organic pigment are precisely controlled by adequately selecting the material, the size and the amount of a dispersing agent, the revolution rate of an apparatus, the dispersion time and the compositions of the coating solution. Whichever an apparatus, a method or a condition may be adapted, the effect of the present invention is realized by applying a coating solution, in which the particles of the organic pigment having the size and shape as mentioned above were dispersed, to form the charge generating layer. The size and shape of the organic pigment in the charge generating layer is obtained by directly observing and measuring the particle contained in the coating film by means of an optical microscope or an electron microscope. The particles observed were in the shape of needle-like.
The charge transporting layer is provided on the charge generating layer thus formed. The charge transporting layer is formed by coating onto the charge generating layer a coating solution, in which at least one of the polymeric compounds such as poly(N-vinylcarbazole), poly(vinylanthracene) or polysilane are dissolved, and drying the coating solution. The charge transporting layer is also formed by coating onto the charge generating layer a coating solution, in which at least one of low-molecular weight compounds such as a hydrazone compound, a pyrazoline compound, an enamine compound, a styryl compound, an arylmethane compound, an arylamine compound and a butadiene compound are dissolved into an organic solvent together with a suitable binder, and drying the coating solution.
Binders for use include at least one of various resins such as polycarbonate, polyester, polyurethane, epoxy, silicone, a styrene resin, an acrylic resin or polyketone. It is preferable that the ratio of the low-molecular weight compound to the binder is within the range from 20 parts by weight to 200 parts by weight of the low-molecular weight compound with respect to 100 parts by weight of the binder. It is preferable that a thickness of the charge transporting layer is within the range from 10 μm to 30 μm. An antioxidant and/or an ultraviolet absorption agent may be added in the charge transporting layer if necessary.
Preparation examples of the coating solutions for the charge generating layers are described as follows.
Preparation example 1
1.6 parts by weight of chloroaluminum phthalocyanine chloride refined by sublimation was added into 50 parts by weight of chloroform and 0.2 part by weight of distilled water. This solution was subjected to dispersion treatment by use of a zirconia bead having a diameter of 1.0 mm as a dispersing agent by means of a sand mill at a temperature of -10° C. for 48 hours. This dispersion solution was gradually added by agitating the solution of 0.8 part by weight of isobutylmethacrylate/butylmethacrylate/2-hydroxymethyl acrylate copolymer (the ratio of each comonomer is 0.45/0.45/0.1 by mol; the weight-average molecular weight Mw=250,000) in 270 parts by weight of chloroform to prepare a coating solution for charge generating layer. This coating solution was applied onto a glass plate to form a coating film with a dry thickness of 0.2 μm. When the phthalocyanine particle were observed by means of the electron microscope (manufactured by Nihon Denshi Co., Ltd.: JSM-T300), the largest value of major axes of the particles was 70 nm, the smallest value of minor axes of the particles was 40 nm and the ratio of the largest value of major axes to the smallest value of minor axes was 1.75.
Preparation example 2
A coating solution was prepared in the same manner as in preparation example 1 except that an atmospheric temperature of the solution containing phthalocyanine is adjusted to 30° C. When the particles of the phthalocyanine in the coating solution were observed in the same manner as in preparation example 1, the largest value of major axes of the particles was 110 nm, the smallest value of minor axes of the particles was 15 nm and the ratio of the largest value of major axes to the smallest value of minor axes was 7.3.
Preparation example 3
1.0 part by weight of copper phthalocyanine of an ε-type was added into 12 parts by weight of cyclohexanone and dispersed for 20 hours by means of a sand mill in the same manner as in preparation example 2. This dispersion solution was gradually added by agitating the solution of 0.5 part by weight of polyvinylbutyral resin (manufactured by Sekisui Chemical Co., Ltd.: Eslec (trademark) BM-2) in 80 parts by weight of methyl ethyl hetone to prepare a coating solution for the charge generating layer. When the particles of the phthalocyanine in the coating solution were observed in the same manner as in preparation example 1, the largest value of major axes of the particles is 1100 nm, the smallest value of minor axes of the particles was 400 nm and the ratio of the largest value of major axes to the smallest value of minor axes was 2.75.
Preparation example 4
A coating solution was prepared in the same manner as in preparation example 3 except that the dispersion time of the phthalocyanine by means of a sand mill was adjusted to 48 hours. When the particles of the phthalocyanine in the coating solution were observed, the largest value of major axes of the particles was 600 nm, the smallest value of minor axes of the particles was 300 nm and the ratio of the largest value of major axes to the smallest value of minor axes was 2.0.
Preparation example 5
10 parts by weight of oxytitanium phthalocyanine having strong diffraction peaks at the Bragg angles (2θ±0.2°) of 9.2°, 13.1°, 20.7°, 26.2° and 27.1° in the X-ray diffraction spectra were added into 10 parts by weight of chloroform. This solution was subjected to dispersion treatment by use of zirconia beads having a diameter of 1.0 mm as a dispersing agent by means of a sand mill at an atmospheric temperature of 30° C. for 20 hours. This dispersion solution was gradually added by agitating the solution of 1.5 parts by weight of polyester resin (manufactured by Toyobo Co., Ltd.: Vylon (Trademark) 200) in 20 parts by weight of cyclopentanone to prepare a coating solution for the charge generating layer.
When the particles of the phthalocyanine in the coating solution were observed in the same manner as in preparation example 1, the largest value of major axes of the particles was 800 nm, the smallest value of minor axes of the particles was 200 nm, the ratio of the largest value of major axes to the smallest value of minor axes was 4.0.
Preparation example 6
1.0 part by weight of oxytitanium phthalocyanine of a preparation example 5 was added into 10 parts by weight of iospropylalcohol. This solution was subjected to dispersion treatment by means of a sand mill with zirconia beads having a diameter of 1 mm as a dispersing agent at a temperature of 5° C. for 40 hours. This dispersion solution was gradually added by agitating the solution of 0.5 part by weight of polyvinylbutyral resin (manufactured by Sekisui Kasei Co., Ltd.: Eslec (Trademark) KS-1) in 20 parts by weight of cyclohexanone to prepare a coating solution for the charge generating layer.
When the particles of the phthalocyanine in the coating solution were observed in the same manner as in preparation example 1, the largest value of major axes of the particles was 500 nm, the smallest value of minor axes of the particles was 200 nm and the ratio of the largest value of major axes to the smallest value of minor axes was 2.5.
Preparation example 7
1.0 part by weight of 4, 10-dibromoanthanthorone (manufactured by ICI Co., Ltd., Monolight red (Trademark) 2Y) refined by sublimation was added into 10 parts by weight of cyclohexanone. This solution was subjected to dispersion treatment by means of a sand mill with zirconia beads having a diameter of 1 mm at an atmospheric temperature of 10° C. for 10 hours.
This dispersion solution was gradually added by agitating the solution of 0.2 part by weight of polyvinylbutyral resin (manufactured by Sekisui Chemical Co. Ltd.,:Eslec (Trademark) BM-1) in 40 parts by weight by cyclohexanone to prepare a coating solution for the charge generating layer. When the particles in the coating solution were observed in the same manner as in preparation example 1, the largest value of major axes of the particles was 1000 nm, the smallest value of minor axes of the particles was 300 nm and the ratio of the largest value of major axes to the smallest value of minor axes was 3.3.
Preparation example 8
A coating solution was prepared in the same manner as in preparation example 7 except that the dispersion time by using a sand mill was adjusted to 24 hours. When the particles in the coating solution were observed, the largest value of major axes of the particle was 500 nm, the smallest value of minor axes of the particles was 250 nm and the ratio of the largest value of major axes to the smallest value of minor axes was 2.0.
Photoconductors were prepared as follows.
Photoconductors 1 to 6
The respective coating solutions for the charge generating layers prepared in preparation examples 1 to 6 as mentioned above was immersion-coated onto the conductive substrates, on which soluble polyamide was coated to the surface of aluminum drum (30 mm in outer diameter, 254.5 mm in length, 1 mm in section thickness and 1.2 μm in a ten-points mean roughness Rz), to become a thickness of 0.1 μm thereby preparing charge generating layers with a dry thickness of 0.4 μm, respectively. Furthermore, the coating solutions of 10 parts by weight of p-diethylamino benzaldehyde-(diphenyl hydrazone) and 10 parts by weight of polycarbonate resin (manufactured by Teizin Kasei Co., Ltd., :TS-2050) in 80 parts by weight of methylene chloride was immersion-coated onto the conductive substrate and then applied onto the charge generating layers to prepare the charge transporting layers with a dry thickness of 20 μm, respectively. Thus, photoconductors 1 to 6 were prepared.
Photoconductors 7 and 8
The respective coating solutions for the charge generating layers prepared in preparation examples 7 and 8 as mentioned above were immersion-coated onto the conductive substrate of a planished aluminum drum (80 mm in outer diameter, 340 mm in length and 1 mm in section thickness) to form the charge generating layer with a dry thickness of 0.8 μm. The coating solution of 10 parts by weight of p-diethylamino benzaldehyde-(diphenyl hydrazone) and 10 parts by weight of polycarbonate resin (manufactured by Teizin Kasei Co., Ltd.,:TS-2050) in 80 parts by weight of methylene chloride was immersion-coated onto the conductive substrate and then applied onto the charge generating layer to form the charge transporting layer with a dry thickness of 25 μm. This photoconductors 7 and 8 were produced.
A phthalocyanine-type pigment was used as a charge generating agent in photoconductors 1 to 6. These photoconductors have sensitivities in a long wavelength light region. Then, these photoconductors were equipped with the laser printer (manufactured by Hewlett Packerd Co. Ltd., Laser Jet II-P), respectively. Image printing-out tests were carried out for a long period of time and the variations of image qualities were examined. The results thus obtained were shown in Table 1. The "l" denotes the largest value of major axes of the particles of the charge generating agent and the "m" denotes the the smallest value of minor axes of the particles of the charge generating agent.
TABLE 1__________________________________________________________________________ The quality of image After the After the After the The geometries image image image of the particle printing- printing- printing- of the charge At the out of out of out of generating agent initial 50,000 100,000 200,000Photoconductor l(nm) m(nm) l/m stage pages pages pages__________________________________________________________________________ 70 40 1.75 The The The The quality quality quality quality of image of image of image of image was good was good was good was good2 110 5 7.3 The Minute Large Many quality black black black of image dots dots dots was good occurred occurred occurred3 1100 400 2.75 Minute Minute Large Many black black black black dots were dots dots dots found increased occurred occurred4 600 300 2.0 The The The The quality quality quality quality of image of image of image of image was good was good was good was good5 800 200 4.0 The Minute Large Many quality black black black of image dots dots dots was good occurred occurred occurred6 500 200 2.5 The The The The quality quality quality quality of image of image of image of image was good was good was good was good__________________________________________________________________________
As shown in Table 1, the photoconductors provided with the charge generating layer which contained the charge generating agent with the largest value of major axes "l" not more than 1000 nm, the smallest value of minor axes "m" not less than 10 nm and a ratio "l/m" not more than 3 could maintain good qualities of images even if the photoconductors have been used for a long period of time.
Subsequently, each of photoconductors 7 and 8 was equipped with the copying apparatus of a roller charging system of the contact charging systems, respectively. Image printing-out tests were carried out for a long period of time and the variations of image qualities were examined. The results thus obtained are shown in Table 2.
TABLE 2__________________________________________________________________________ The quality of image After the After the After the The geometries image image image of the particle printing- printing- printing- of the charge At the out of out of out of generating agent initial 50,000 100,000 200,000Photoconductor l(nm) m(nm) l/m state pages pages pages__________________________________________________________________________7 1000 300 3.3 Fog was Minute Large Many slightly black black black found dots dots dots occurred occurred occurred8 500 250 2.0 The The The The quality quality quality quality of image of image of image of image was good was good was good was good__________________________________________________________________________
As shown in Table 2, the photoconductor provided with the charge generating layer which contained the charge generating agent with the largest value of major axes "l" not more than 1000 nm, the smallest value of minor axes "m" not less than 10 nm and a ratio "l/m" not more than 3 could clearly maintain good qualities of images even if the photoconductor has been used for a long period of time by means of the apparatus of the contact charging system.
The present invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and it is the intention, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention. | An electrophotographic photoconductor for an electrophotographic apparatus which employs contact charging, includes a conductive substrate; and a photoconductive layer for contacting an electric conductor, which photoconductive layer includes a charge generating layer which is formed on the conductive substrate and which comprises a binder and a charge generating agent comprised of particles of phthalocyanine pigment or 4,10-dibromoanthanthrone pigment dispersed in the binder; and a charge transporting layer which is formed on the charge generating layer, wherein the particles of pigment have a major axis which does not exceed 1000 nm and a minor axis which is not less than 10 nm, and wherein the particles of pigment have a ratio of the major axis to the minor axis which does not exceed 3. Alternativly, the charge transporting layer is formed on the conductive substrate and the charge generating layer is formed on the charge transporting layer. | 6 |
This application is a division of application Ser. No. 08/315,801, filed Sep. 30, 1994 now U.S. Pat. No. 5,441,797 which is a division of application Ser. No. 08/054,500 filed Apr. 27, 1993 now U.S. Pat. No. 5,397,684.
FIELD OF THE INVENTION
The invention relates to antireflective polyimide layers used in photolithography to fabricate semiconductor devices.
BACKGROUND OF THE INVENTION
Photolithography using ultraviolet light is a fundamental technology in the production of semiconductor devices. In the integrated circuit (IC) lithographic process, a photosensitive polymer film is applied to the silicon wafer, dried, and then exposed with the proper geometrical patterns through a photomask to ultraviolet (UV) light or other radiation. After exposure, the wafer is soaked in a solution that develops the images in the photosensitive material. Depending on the type of polymer used, either exposed or nonexposed areas of film are removed in the developing process. The majority of Very Large Scale Integration (VLSI) exposure tools used in IC production are optical systems that use UV light. They are capable of approximately 1 μm resolution, ±0.5 μm (3σ) registration, and up to 100 exposures per hour; they are commonly operated at 405 nm (so-called H-line) or 436 nm (so-called G-line).
A frequent problem encountered by resists used to process semiconductor devices, is reflectivity back into the resist of the activating radiation by the substrate, especially those containing highly reflecting topographies. Such reflectivity tends to cause standing wave ripples and reflective notches, which interfere with the desired pattern in the photoresist. The notches are particularly bad when the support or metallurgy is non-planar.
The problem is illustrated in FIG. 1, which depicts a substrate 1 on which has been formed a metal pattern 3. The metal has been covered with a polyimide dielectric 5 and the polyimide layer planarized. A resist 7 has been deposited and is being exposed through a mask 9. Incident radiation passes through the apertures in the mask and, in an ideal situation, exposes only those areas 11 directly in line with the apertures. Unfortunately when the metal pattern 3 is highly reflective, as it usually is, the reflected light from the metal and, to a lesser extent, from the substrate impinges on areas of the resist not intended to be exposed.
The art discloses two basic approaches to the problem: (1) change the wavelength of the radiation and (2) incorporate some sort of radiation absorber into or under the photoresist. The first approach is awkward and expensive because it requires a new tool set. The second approach and its addendant drawbacks are illustrated in FIGS. 2 and 3. In FIG. 2 a dye containing a chromophore that absorbs at the appropriate wavelength is incorporated in the resist layer; this cuts down on reflected radiation but also on resist sensitivity. In FIG. 3 a dye containing a chromophore of appropriate absorption is incorporated in a special layer 13 beneath the resist 7; this adds to the process additional steps for the deposition and removal of the layer.
A superior process could be envisioned if it were possible to incorporate a dye into the polyimide layer itself (FIG. 4). While this is a fine idea in theory, in practice it is not straightforward. Since the polyimide will remain as part of the semiconductor device, the modified polyimide layer must be deposited as a normal polyimide layer would be, and then it must survive subsequent curing, planarization and metal deposition cycles in which the temperature exceeds 400° C. Typical UV-absorbing dyes such as curcumin and bixin, when incorporated into polyimide films give rise to dielectric films that are not stable above 300° C. Typical pigments that might be thermostable are insoluble and give rise to problems of homogeneity. Thus there is a need for an antireflective polyimide layer that processes normally and that is extremely thermally stable.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an antireflective dielectric layer that will survive high temperature processing.
It is a further object to provide a polyimide composition that absorbs radiation in the 400 to 450 nm range and that is stable above 400° C. It is a further object to provide a photolithography process that substantially eliminates problems of reflectivity without adding any processing steps.
These and other objects, features and advantages are realized in the present invention Which relates generally to a process of making a semiconductor structure in which a polyimide is used as an interlevel dielectric. According to the process, a chromophore is introduced into the polyimide film. During subsequent patterning steps, the modified polyimide film absorbs radiation so that it does not reflect and expose the resist in undesired areas. A suitable chromophore must absorb radiation in the 400-450 nm region. Its host molecule must be thermally stable at temperatures greater than 400° C. and soluble as part of the mixture with the polyimide precursor (polyamic acid or polyamic ester) material.
In one aspect, the invention relates to a process for making circuit elements by photolithography comprising:
(a) depositing an antireflective layer on a substrate. The antireflective polyimide layer comprises a polyimide, polyamic acid, polyamic ester or combination thereof and contains a sufficient concentration of at least one chromophore to give rise to an absorbance sufficient to attenuate radiation at 405 or 436 nm; and
(b) heating the antireflective layer at 200° to 500° C. to provide a functional circuit element that includes the antireflective polyimide layer.
As a practical matter, the process will usually include the intermediate or subsequent steps normally attendant to photolithographic processes, namely depositing a photoresist over the polyimide layer, imaging the photoresist with actinic radiation, preferably at 405 or 436 nm, developing the photoresist, using it to pattern a layer beneath the resist and removing the resist. Alternately, the photoresist can be deposited over the uncured antireflective layer, and when the layer comprises a polyamic acid, it can be developed along with the photoresist. The polyimide is then cured after removing the photoresist.
Preferred chromophores, which may occur either in a dye that is a component of the polyimide layer or in a recurring unit in a polyimide polymer, include those chromophores arising from naphthalenes, anthraquinones or perylenes.
In another aspect the invention relates to a thermostable polyimide film comprising a polyimide and a thermostable dye. The dye has a molar extinction coefficient (ε) greater than 5000 between 400 and 450 nm and a solubility of at least 2 g/L in an inert, organic solvent. A preferred solvent is N-methylpyrrolidone (NMP). After cyclization, the film exhibits less than 1%, and preferably less than 0.5%, decrease in weight when heated at 450° for 20 minutes. One group of suitable dyes includes precursor amic acids which form materials such as perylene red. The cyclized materials are members of the genus of formula I ##STR1## The precursors are of formula V ##STR2## wherein R 1 and R 2 are independently chosen from the group consisting of phenyl; phenyl substituted with one or more lower-alkyl, lower-alkoxy, halogen or nitro; naphthyl and naphthyl substituted with one or more lower-alkyl, lower-alkoxy, halogen or nitro and R 10 is hydrogen or alkyl of one to four carbons.
Other suitable dyes, such as precursors VIII to indanthrene brilliant orange, give rise to members of the genus of formula II ##STR3## wherein Ar 5 and Ar 6 are independently chosen from the group consisting of phenyl, anthraquinone, phenyl substituted with lower-alkyl, lower-alkoxy, halogen or nitro; naphthyl; and naphthyl substituted with lower-alkyl, lower-alkoxy, halogen or nitro. Still other dyes are members of the genus of formula III ##STR4## and their precursors XII ##STR5## wherein Ar 7 is selected from the group consisting of phenyl; naphthyl; phenyl substituted with one or more lower-alkyl, lower-alkoxy, halogen or nitro; and Ar 8 is an anthraquinone residue.
The invention also relates to semiconductor devices comprising at least one functional IC and a polyimide film as described above.
In another aspect the invention relates to a polyimide comprising repeating units of formula IV ##STR6## wherein Ar 1 is selected from the group consisting of ##STR7## Ar 2 is selected from the group consisting of ##STR8## Ar 3 is selected from the group consisting of residues encompassed by Ar 1 plus ##STR9## Ar 4 is selected from the group consisting of residues encompassed by Ar 2 plus ##STR10## m is from zero to 100; and n is from 1 to 100;
with the proviso that at least one of Ar 3 and Ar 4 must be other than a substituent chosen from the groups Ar 1 and Ar 2 .
Preferred polyimides include those in which m is 90 to 99 and n is 1 to 10, those in which Ar 3 is ##STR11## and Ar 4 is Ar 2 , and those in which Ar 3 is Ar 1 and Ar 4 is ##STR12##
In another aspect, the invention relates to blended polyimides comprising a first component, which is a conventional polyimide comprised of the groups Ar 1 and Ar 2 and a second component which is a polymide of formula IV.
In another aspect the invention relates to semiconductor devices comprising at least one functional IC and a polyimide film as described above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 to 3 are schematic cross-sections of devices of the art; and
FIG. 4 is a schematic cross-section of a device according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
Four criteria must be met in providing an antireflective polyimide layer that will remain a part of a functional IC device: (1) the layer must function normally as a dielectric, (2) the layer must behave like a normal polyimide in fabrication processes, (3) the layer must be stable above 400° C., and the layer must have a sufficient absorbance to provide a practical barrier to reflected radiation. In accordance with the invention, there are provided two approaches to such a layer: (1) incorporate a dye meeting the foregoing criteria into a conventional polyimide precursor solution or (2) incorporate a chromophore into the polyimide polymer itself without impairing the mechanical and electrical properties of the cured polymer.
Dyes that have been found suitable for incorporation into the precursor mix include soluble amic acid precursors to perylene red ##STR13## and indanthrene brilliant orange (formula II; Ar 5 =Ar 6 =phenyl). The dyes are not usually incorporated into the spin-coating mix in their imide (cyclized) forms, but rather, like the polyimide itself, are incorporated in the formulation as their amic acid or ester precursors and are then cyclized in situ when the polyamic acid or ester is cured. In addition, condensation products of perylenetetracarboxylic acid with aromatic amines and condensation products of anthraquinone diamines with aryl orthodicarboxylates have been found to possess suitable chromophores while exhibiting compatible solubility in normal casting solvents such as N-methylpyrrolidone (NMP). Moreover the films formed from these dyes in combination with conventional polyamic acids and esters are surprisingly often more thermally stable than the corresponding unmodified polyimide layers. The absorbance through a one micron layer will normally be at least 0.05 and preferably greater than 0.3 at 405 or 436 nm. This is sufficient to usefully attenuate most radiation that would give rise to a reflection problem.
The dyes may be made by reacting perylene dianhydride (PDA) with two moles of the appropriate monoamine to form the amic acid V, which, when heated, cyclizes to the imide, as shown in Scheme A: ##STR14## A mixture of amines can be used to make peryleneimides having differing R groups.
Indanthrene-type (fused benzimidazole) dyes of formula II may be synthesized analogously from a cyclic dianhydride and two moles of an orthodiamine VII, as shown in scheme B: ##STR15## As before, a mixture of amines will produce compounds of formula II having differing Ar groups. Two examples are fused imidazoles IX and X, made from PMDA and diaminonapthalene or diaminoanthraquinone: ##STR16## The dyes of genus III may be prepared similarly from two moles of a cyclic monoanhydride and one mole of a non-ortho diamine: (Orthodiamines tend to cyclize to fused benzimidazoles as above.) ##STR17## In all of the foregoing Schemes, the initial reaction is carried out to produce the amic acid (e.g. V, VIII, XII) which is coated on the substrate in solution and then cured to the final product after deposition. The important features of all three classes of dyes are that, probably as a result of analogous structures, their precursors have compatible solubility to that of polyamic acids and esters for spin coating the resins, and the chromophores can be modulated by appropriate substitution to achieve the necessary absorbance between 400 and 450 nm.
From consideration of Schemes A, B and C, particularly B, one can envision that by using a UV-absorbing dianyhydride or diamine one could make polyamic acids, similar to VIII, which could then be inserted into conventional polyamic acid precursors for polyimide films: ##STR18## This may be accomplished by mixing the anhydrides and diamines in the proper stoichiometry for the desired absorbance and physical properties. We have found that about 1 to 10% of one component having the UV-absorbing chromophore produces useful polyamic acids for the production of polyimide films of 0.5 to 5 μm thickness. If thinner films are desired, the proportion of absorbing precursor can be increased. The actual amount to be used will depend on the extinction coefficient of the particular chromophore and the amount of absorbance needed for a particular application.
An example of a film according to Scheme D wherein the stoichiometry includes no component XVI is shown below: ##STR19## Similar polyamic acids can be made using a UV-absorbing diamine, such as 1,5-diaminoanthraquinone as the XVI component in place of or in addition to XVa. However, adjustments in stoichiometry of the components must be made to account for the low reactivities of aromatic diamines with XVa.
Alternatively, one can make UV-absorbing polyamic acids and make physical mixtures with conventional polyamic acids or esters. Conventional polyamic acids and their constituent diamine/dianhydride components are described, for example, in U.S. Pat. No. 4,480,009 (column 18 to 22) the disclosure of which is incorporate herein by reference. These mixtures can then be cured to make blended polyimides rather than copolymers, i.e. physical mixtures rather than covalent compounds.
The polyamic esters may be prepared by methods well-known in the art, for example by reacting the anhydride with an alcohol followed by thionyl chloride and then the diamine. The esters have certain advantages when it is desired to heat the polyamic ester precursor (for example to drive off solvent) without having it cyclize to a polyimide. The ester can then be cyclized to the polyimide by raising the temperature.
EXAMPLE 1
(Formula II: Ar 5 =Ar 6 =naphthalene)
To a solution of 15.82 g (100 mmol) of 2,3-diamino naphthalene in 100 mL of NMP was added 3.4 g (50 mmol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride (NDA), and the formulation was mixed on a roller mill for 16 hours to form the 2:1 amic adduct. Ten grams of this solution was added to 75 g of a 16% solution of polyamic ethyl ester (PAETE). The NMP solution was spin coated on a quartz substrate to a thickness of 2 μm and heated at 350° C. for 20 min. The resulting film exhibited absorbance of 0.68 at 405 nm and 0.35 at 436 nm; thermogravimetric analysis (TGA) indicated a weight loss of 0.18% when heated from 350° to 450° over a period of 100 minutes.
EXAMPLE 2
(Formula II: Ar 5 =Ar 6 =anthraquinone)
The procedure of example 1 was followed using 1,2-diaminoanthraquinone in place of 2,3-diaminonaphthalene. The resulting film exhibited absorbance of 0.90 at 405 nm and 0.45 at 436 nm; thermograviometric analysis showed a weight loss of 0.12% on heating from 350° to 450° over 100 minutes.
EXAMPLE 3
(Formula IV: Ar 1 =phenyl, Ar 2 =xylyl, A 3 =perylene, Ar 4 =xylyl, m=99 and n=1)
3,4,9,10-Perylenetetracarboxylic dianhydride (0.625 g) (1.59 mmol) (PDA) Was reacted with 10 g (73.42 mmol) of m-xylylenediamine by combining reagents and mixing the reactants on a roller mill. After 18 hours 150 mL of NMP and 15.667 g (71.93 mmol) of pyromellitic dianhydride (PMDA) were added to the mixture and the reactants mixed again for 24 hours. This copolymer produced good amic acid films that imidized to a red polyimide according to the procedure described in example 1. The polyimide film exhibited absorbance of 0.11 at 405 nm and 0.13 at nm; TGA showed a weight loss of 0.15% under the usual program.
EXAMPLES 4-7
(Formula IV: Ar 3 =phenyl, Ar 4 =anthraquinone, m=0) plus PAETE
As examples of copolymer blends (physical mixtures of polyimides), four diaminoanthraquinones were individually reacted with one equivalent of PMDA at 0.5 mmol/mL in NMP to produce amic acid solutions of 18.5% solids. The solutions were mixed 1:9 with PAETE, spin coated and heated at 350° C. to give copolymer blends suitable for device coating.
______________________________________ AminoExample Substitution post 350° C. λ.sub.max______________________________________4 1,2 4065 1,4 400,4806 2,6 350,4907 1,5 432______________________________________
1,5-Diaminoanthraquinone (Example 7) gave rise to films with absorption maxima at 432; these are particularly advantageous for mercury G-line photolithography.
EXAMPLE 8
(Formula IV: Ar 1 =phenyl, Ar 2 =Ar 4 =xylyl, Ar 3 =perylene, m=98, n=2)
A copolymer was prepared by adding excess m-diaminoxylene to perylenedianhydride. The resulting 2:1 amine/anhydride adduct formed as a dark precipitate which was dissolved and incorporated as a block along a polyamic acid copolymer chain with PMDA as the major anhydride link. A stoichiometry of 2.1% perylene gave the resulting copolymer significant red color in the imidized film. This copolymer provides good film quality, but the UV absorption maxima are at 496 and 533 with only a shoulder at 464.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that other changes in form and details may be made therein without departing from the spirit and scope of the invention. | A process is disclosed for making circuit elements by photolithography comprising depositing an antireflective polyimide or polyimide precursor layer on a substrate and heating the substrate at 200° C. to 500° to provide a functional integrated circuit element that includes an antireflective polyimide layer. The antireflective polyimide layer contains a sufficient concentration of at least one chromophore to give rise to an absorbance sufficient to attenuate actinic radiation at 405 or 436 nm. Preferred chromophores include those arising from perylenes, naphthalenes and anthraquinones. The chromophore may reside in a dye which is a component of the polyimide coating mixture or it may reside in a residue which is incorporated into the polyimide itself. | 8 |
FIELD OF THE INVENTION
The present invention relates to a pot spinning machines and methods utilizing spinning pots that rotate during spinning and rewinding, wherein the fiber material to be spun is delivered from a drafting arrangement to a tubular yarn guide associated with each spinning pot which delivers the spun yarn via a mouth in the yarn guide to progressively form a yarn cake in the spinning pot. After the conclusion of the spinning operation or upon a yarn break, the yarn cake must be wound up onto a rewinding tube held in readiness during spinning at the mouth of the yarn guide spaced apart from its rewinding position.
BACKGROUND OF THE INVENTION
Pot spinning is also known as centrifugal spinning, and hence the apparatus utilized for performing such spinning are referred to as pot or centrifugal spinning frames or machines. Such machines either have tubular pots both ends of which have openings of virtually equal size, suspended pots which have a downward opening on the underside of the pot for removing the spun yarn, or standing pots with an upward opening for removal of the spun yarn located at the top of the pot. Reference in this respect is made to German Patent Disclosure DE 41 08 929 A1. There are also pot spinning machines wherein, once the yarn cake in the pot has been finished, the yarn guide is first pulled out of the pot and a tube is then inserted into the pot to initiate the rewinding operation (see Swiss Patent CH 360 004). Other pot spinning machines have a cylindrical spinning pot open at the top and bottom, with a yarn guide introduced through the upper opening during spinning and with a corresponding bobbin tube inserted through the lower opening for rewinding (see German Patent Disclosure DE 43 24 039 A1). Finally, there are pot spinning machines in which the rewinding tube is predisposed in a ready position during spinning coaxially on the yarn guide or yarn guide tube. These machines may utilize either standing spinning pots or spinning pots that are cylindrical with openings at each end (see East German Patent DD 21 834 and German Patent Disclosure DE 43 24 039 A1).
There are also pot spinning machines with substantially cylindrical pots that lack any top and bottom, known as tube centrifuges, both ends of which have an opening of virtually the same size. Such tubular spinning pots may be magnetically-supported as in German Patent Disclosure DE 42 08 039 A1. According to German Patent Disclosure DE 43 24 039 A1, it is also possible with a standing tubular spinning pot of the kind known from East German Patent DD 21 834, that during spinning, the rewinding tube (onto which the yarn cake is to be wound) is predisposed on the tube of the yarn guide above the mouth thereof and locked thereat to prevent its being lowered. In this reserve position, the tube does not touch the rotating loose end of the yarn.
In these known cases, the rewinding tube can be held in readiness either above or below the spinning pot and thrust into the path of the loose end of the yarn as needed. If the rewinding tube is not thrust forward at the correct time in the event of a yarn break, then the torn end of the yarn in the pot runs along the inner wall of the yarn cake and can no longer be located and manipulated automatically with known devices. In that case, the rewinding operation can be initiated only from outside, generally manually, by relatively complicated procedures (see Swiss Patent CH 348 346 or German Patent DE 842 916).
In German Patent Disclosure DE 26 21 900 A1, an optical yarn monitor is disclosed to be located quite close to the point at which the yarn is created and records not only the presence but also the proper motion of the yarn. This known yarn monitor, which is preferentially used in ring spinning machines, is positioned adjacent an associated drafting arrangement at the base of the balloon forming above the spindle. The yarn sensor is intended to initiate protective provisions in the event of a yarn break, such as shutting off the following processing station.
As mentioned above, to initiate the rewinding operation, the rewinding tube is placed in the pot. In this connection, it has long been known for the loose end of the yarn furnished from the mouth of the yarn guide to be caught with the aid of a groove provided on the lengthwise end of the rewinding tube (see U.S. Pat. No. 802,161, page 2, lines 58/59). Mechanical means are also known for grasping the inner yarn layers of the yarn cake in the event of a yarn break, to enable the rewinding operation to be initiated, either by hand (see Swiss Patent CH 348 346, page 1, lines 18 ff.) or via a swiveling mechanism (see German Patent DE 842 916, page 4, lines 13-23).
In all of these known devices that initiate the rewinding operation after a yarn break, some layers of yarn are deposited randomly onto the rewinding tube which can lead to considerable problems in the later winding process in that it is generally not possible to unwind these random yarn layers from the tube. This produces additional waste, and the tubes require special cleaning.
In German Utility Model DE-GM 76 25 081, a tubular bobbin tube is disclosed that is entirely cylindrical and has a yarn catching slit with an associated yarn retaining element at a lengthwise end on the outer circumferential surface of the tube. A similar cylindrical bobbin tube with an encompassing yarn catching slit is disclosed in German Patent Disclosure DE 27 17 189 A1. In the latter case, the yarn catching slit may also be provided on the face-end edge of the tube (page 7, paragraph 4). A yarn catching slit with integrated yarn clamping means at a lengthwise end of a cylindrical bobbin tube is disclosed in European Patent Disclosure EP 0 524 545 B1. All of these known yarn catching slits are intended to be able to grasp and hold only a yarn that is pressed approximately radially with tension into the respective slit.
OBJECT AND SUMMARY OF THE INVENTION
In view of the above-described known pot spinning machines, it is an object of the present invention to provide a means to rescue or retrieve for purposes of further processing the already-spun yarn cake or the yarn contents of the centrifuge in a pot spinning machine, even in the event of a yarn break.
Basically, the present invention provides a yarn sensor associated with the transport path of the yarn in a pot spinning operation to detect the occurrence of a yarn break, and an associated means connected with the sensor for shifting the rewinding tube into a rewinding position when a yarn break is detected. Accordingly, when a yarn break during the pot spinning operation is detected by the yarn sensor, the rewinding tube may thereupon immediately be moved into its rewinding position, preferably with the broken yarn end being clamped at the same time, so that the yarn cake already located in the pot is immediate rewound to the rewinding tube. In this manner, the invention makes it possible to move the rewinding tube into its rewinding position before the broken yarn end has left the mouth of the yarn guide. As a result, it is assured that the contents of the pot will be rewound even if there is a yarn break, and that the yarn end cannot be deposited irretrievably on the yarn cake.
In the present invention, the rewinding tube is preferably locked on the tube of the yarn guide in a reserve position above the mouth of the yarn guide during the normal ongoing spinning operation. In the event of a yarn break, all that is needed to initiate rewinding is to release the locking means, so that the rewinding tube drops past the mouth of the yarn guide. Conversely, if the rewinding tube is normally located below the mouth of the yarn guide tube during the spinning operation, for instance, in the case of a suspended or tubular spinning pot, then the rewinding operation can likewise be initiated instantaneously in the event of a detected yarn break by quickly thrusting the rewinding tube upwardly beyond the yarn guide mouth. In both cases, the end of the rewinding tube adjacent to the yarn guide mouth should be held in readiness as close as possible to the mouth, so that the extraordinarily short time available from the time a yarn break is detected until the yarn end emerges from the mouth of the yarn guide will suffice to catch the yarn end for the sake of rewinding. For the above purpose, the adjacent end of the rewinding tube is positioned only far enough away from the yarn guide mouth as to not impede the operation of spinning or winding the yarn cake.
According to another aspect of the invention, the yarn sensor signal produced in the event of a yarn break is utilized to initiate not only the described movement of the rewinding tube past the yarn guide mouth, but also clamping of the broken yarn end in the region of the yarn guide tube or at the forward-moving end of the rewinding tube, so that continued rotation of the pot unchanged must necessarily rewind the yarn cake contained in the pot onto the tube.
Preferably, the rewinding tube is moved with sufficient quickness upon a yarn break to reach the rewinding position before the torn yarn end leaves the mouth of the yarn guide tube. Since only a fraction of a second is available for this purpose, it is advantageous if the yarn sensor is located upstream along the yarn path as far as possible in advance of the yarn guide mouth. A position in the vicinity of a preceding fiber drafting arrangement, i.e., immediately following the triangular conformation of the fibers being spun as they exit the drafting arrangement in direction of the yarn travel, is preferred. The fiber spinning triangle is not only located relatively far from the yarn guide mouth but also represents an especially difficult region in that yarn breaks during the spinning operation in pot spinning machines occur predominantly in the region of the spinning triangle. A yarn sensor disposed below the spinning triangle, preferably still upstream of the adjacent entrance to the yarn guide tube, can therefore detect a yarn break quickly enough that the rewinding tube may be brought into its rewinding position long before the yarn end leaves the mouth of the yarn guide tube, so that the still-rotating loose end of the yarn may be fixed in notches or clamping devices at the base of the rewinding tube.
Because of this provision for the early detection of a yarn break in the same region where such breaks typically occur, enough time remains to initiate the associated emergency provision of rapidly raising or lowering of the rewinding tube from the reserve position held in readiness above or below the spinning pot into the rewinding position. From an energy standpoint, it is more favorable to allow a tube to drop rather than to raise the tube, it is preferable for the rewinding tube to be held in readiness in an upper position on the tube of the yarn guide above the yarn guide mouth.
In this reserve position, the rewinding tube can be fixed, for instance with the aid of a magnet. Since the release of a thusly suspended rewinding tube can occur very quickly, and the distance the tube must travel from the reserve position to the rewinding position is short, the rewinding operation can be initiated virtually instantaneously, not only at the end of yarn cake buildup but in the interim as well in the event of a yarn break or some other interruption in the spinning operation. Almost equally quickly, a rewinding tube held ready below the yarn guide mouth can be raised from its reserve position to the rewinding position, for instance by spring force.
According to a further feature of the invention, the described reserve position of the rewinding tube on the yarn guide enables not only a yarn break to be detected quickly by the yarn sensor and the direct release of the rewinding tube thereupon, but also accomplishes the particular advantage of enabling the locking of the rewinding tube to be designed such that upon its release the rewinding tube simultaneously clamps the yarn end sliding through the yarn guide tube, preferably by means of one and the same motion. In other words, one and the same mechanism, such as a control magnet initiated by the yarn sensor, locks the rewinding tube in the reserve position, and in the other position it clamps the yarn end sliding through the tube of the yarn guide.
In a particular embodiment of the invention, provision is made for initiating the rewinding operation, especially after a yarn break, even if there is no longer any revolving loose end of the yarn between the yarn guide mouth and the yarn cake such that all the fiber material deposited in the spinning pot or centrifuge is wound onto the rewinding tube and later can be unwound from it again without any loss. In normal spinning operation, a loose end of the yarn extends radially between the mouth of the yarn guide tube and the spun yarn cake. However, in the event this loose end of yarn is no longer available, the present invention advantageously serves instead to initiate the rewinding operation by utilizing a different starting length of yarn, namely a length of yarn that has already left the deposition path radially extending from the yarn guide and has already applied itself loosely to the inner wall of the yarn cake. Specifically, the rewinding operation may be initiated utilizing a broken yarn end that has been applied to the inner wall of the yarn cake not exactly circularly but rather partly in the orientation of a chord relative to the interior of the pot and which therefore extends essentially in a radial plane of the pot approximately along the circumference of the rewinding tube.
According to a further feature of the invention, at least one of the lengthwise ends of the rewinding tube has a radially protruding flanged portion with a yarn catching notch therein partially covered by a spring element, the widened portion being positioned to project into close adjacency with the yarn cake almost close enough to touch the inside surface of the yarn cake. As a result, a yarn chord segment utilized such as above-mentioned for initiating the rewinding operation will extend essentially parallel to the circumferential direction, or in the plane of, the radially protruding widened portion and can be firmly retained.
This outcome is surprising. Conventional catching notches on rewinding tubes are known not to be able to properly hold a chord-like yarn end firmly and to use such a yarn end for ordered rewinding of a yarn cake. This is because the applicable chord-like yarn segment rests only loosely and without tension (in the radial plane of the catching means) on the inside face of the yarn cake. The known catching means are designed such that the chord segment, if it is touched at all, passes only loosely through the yarn catching notch.
However, the functional integration of the characteristics preferably employed to construct the present apparatus, namely the maximum possible radius of the radially protruding widened end portion of the rewinding tube, the catching notch located on the edge of the widened end portion, and the spring element of the catching notch, lead to complete success that could not have been expected in advance from these individual characteristics.
As noted, it is preferably provided that the catching notch is positioned as close as possible to the inside diameter of the yarn cake, so that it can reliably grasp any chord-like yarn segment that develops. In accordance with a preferred embodiment, it is especially favorable for the plate-like widened portion to be inwardly recessed at its axial end face for receiving the spring element, and for the spring element to partially cover the catching notch at a distance, measured from the axial end of the widened portion, that is equal to or greater than a yarn diameter. A snap ring is preferably provided as the spring element.
Thus, the present invention accomplishes a pot spinning method by which it is assured that the yarn cake in the spinning pot will be automatically rewound properly even in the event of a yarn break, without requiring a search for the yarn end on the yarn cake. That is, in the event of a yarn break, if against expectation the loose end of the yarn extending from the yarn guide mouth to the yarn cake should prove not to have been grasped, then the present invention assures by means of the method carried out by the described apparatus that a yarn end applied circumferentially in the form of a yarn chord segment onto the inside face of the yarn cake is utilized to initiate the rewinding operation. Various conventional devices are possible as the yarn sensor, which by way of example may function optically or capacitively. One example of an optical yarn sensor or yarn monitor is disclosed in German Patent Disclosure DE 26 21 900 A1.
The invention will be described below in further detail in terms of the exemplary embodiments shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 1a are vertical longitudinal sections through a pot spinning station according to the present invention, shown in the spinning position;
FIG. 2 shows a device for locking the rewinding tube on the yarn guide in the pot spinning station of FIGS. 1 and 1a;
FIG. 3 shows an alternative embodiment of pot spinning station having a rewinding tube that can be inserted from below the spinning pot;
FIG. 4 is a detailed view of one end of the rewinding tube according to the present invention on a larger scale; and
FIG. 5 shows the rewinding tube of FIG. 4 in the direction of the arrow X of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the accompanying drawings and initially to FIG. 1, a representative spinning station of a pot spinning machine is shown. In advance of the spinning pot is a drafting arrangement 1, typically having a series of drafting roller pairs but symbolized in FIG. 1 only by the last pair of drafting rollers, wherein a sliver 2 is drawn and as it emerges from the last roller pair is twisted under the influence of the revolving spinning pot 9 so as to converge in a spinning triangle 3 into a yarn 17. The yarn 17 then immediately passes through a yarn sensor 4 located directly following the spinning triangle 3 and enters an entrance end to a tubular yarn guide 5. The yarn 17 emerging from the exit mouth 6 of the yarn guide 5 is applied to the inner wall 8 of the spinning pot 9 and wraps centrifugally thereagainst to progressively form a yarn cake 10. During the spinning operation, a rewinding tube 11 is located coaxially on the yarn guide 5, immediately above and spaced from its mouth 6, from which position the rewinding tube 11 can be lowered past the mouth 6 of the yarn guide 5 to initiate a rewinding operation (as indicated by the position 12 shown in broken lines and discussed more fully below).
A rewinding operation may be initiated for several reasons. On the one hand, if the yarn cake 10 in the spinning pot 9 has been completed, or on the other hand, if an interruption in the spinning operation has occurred, for instance from yarn breakage, rewinding will be initiated. The base of the rewinding tube preferably has suitable clamping or retaining devices. Thus, when the rewinding tube 11 is lowered outwardly past the mouth 6 of the yarn guide 5 into the rewinding position 12 shown in broken lines, the rotating loose trailing end 7 of the yarn 17 forming the yarn cake in the spinning pot can be grasped by clamping or retaining devices and fixed such that the yarn cake 10 is automatically or by compulsion wound onto the rewinding tube 11 as the spinning pot 9 continues to rotate.
The rewinding tube 11, once wound with the yarn from yarn cake in the spinning pot, can then be transferred to a caddy 13, having a flat base 15 and an upstanding spindle 14 for coaxially supporting the rewinding tube 11, that is held ready at a suitable spacing below the spinning pot 9. After being lowered in the direction of the arrow 16, the wound tube 11 can be carried away together with the caddy 13 for further processing, while a new empty tube is brought with a further caddy (not shown) and fixed below the yarn guide 5 in the reserve position.
The rewinding tube 11 is held in the reserve position on the yarn guide 5 above its exit mouth 6 during normal ongoing centrifugal winding of the yarn cake in the spinning pot by a locking means 19 shown in FIG. 2. If the yarn sensor 4 detects a yarn break, the yarn sensor 4 transmits a signal to the locking means 19 to release the rewinding tube 11. The locking means 19 thereupon disengages from the rewinding tube 11, so that the rewinding tube 11 drops downwardly and the rewinding operation is initiated. For initiating the rewinding operation, it is advantageous if the rotating loose end 7 of the yarn between the yarn guide mouth 6 and the yarn cake 10 has a sufficient tension to catch the yarn end on the tube and fix it. An adequate tension for this purpose may under some circumstances already exist if the yarn end is long enough. It is especially advantageous, however, for the yarn end to be clamped or otherwise firmly held or caught and for the rewinding operation to be initiated immediately thereafter.
The locking means 19 shown in FIG. 2 is a preferred exemplary embodiment that is suitable both for keeping the rewinding tube 11 in its reserve position on the tube of the yarn guide 5 and in the event of a yarn break, by switchover of the locking means, for clamping the yarn 17 or its trailing yarn end, in the axial interior channel 18 of the yarn guide 5. To that end, the locking means 19 includes an electromagnet 22 which is switchable by the supply of electrical current to its electromagnetic windings in response to signals furnished by the yarn sensor 4 to act upon and displace a locking pin 20 or the like to move between the position indicated by solid lines, wherein the pin 20 extends radially outwardly into engagement within an interior recess in the rewinding tube 11 to lock the rewinding tube 11 in its reserve position, and a position 21 represented by broken lines, wherein the locking pin 20 extends radially inwardly into the channel 18 of the yarn guide 5 into clamping engagement with the yarn end 17 therein. During a switchover from the tube locking position to the yarn clamping position, the rewinding tube 11 is released to slide downwardly into its rewinding position which is predetermined by means of a stop 23 affixed to the yarn guide 5 that is preferably biased outwardly by spring force to engage in another interior recess within the rewinding tube 11 as it drops into the rewinding position. It is equally possible for the stop 23 to have an electromagnetic drive 24, to enable the stop 23 to be retracted and the rewinding tube 11 thus to be released.
FIG. 3 shows another embodiment of a spinning station of a pot spinning machine, which is substantially identical to the spinning station of FIG. 1 except that, in this embodiment, the rewinding tube 11 is introduced into the spinning pot from beneath.
In pot spinning machines according to the present invention in which the rewinding tube is already held in readiness in a reserve position during the spinning operation so that the rewinding tube can be immediately brought to the rewinding position, the rewinding tube should be moved into the rewinding position in the event of a yarn break so quickly that the yarn cake already formed in the spinning pot can still be properly rewound. Thus, according to the present invention, the yarn break is detected with the aid of the yarn sensor 4, which thereupon sends a signal for instantaneously moving the rewinding tube into the rewinding position and for clamping the yarn end.
FIG. 1A schematically shows a spinning station of another pot spinning machine wherein a spinning pot 9 rotates in bearings 25 about an axis 26. The type of bearings are of no significance with respect to the present invention; however, it is known to use magnet bearings, for instance to support single-motor-driven spinning pots.
A sliver drawing device, such as a drafting mechanism 1 to which is supplied a sliver 2, is installed above the spinning pot 9. The yarn 17 created by the action of the revolving spinning pot 9 is applied into the interior of the spinning pot 9 via a yarn guide tube 5 supported for axial movement and the yarn is thereby wrapped centrifugally onto the inner wall 27 of the rotating spinning pot, forming a yarn cake 10.
A rewinding tube 11 is fixed in a ready position on the yarn guide tube 5 by means of a latching device 19, which is triggerable in a defined fashion to shift the rewinding tube 11 downwardly beyond the mouth of the yarn guide 5 into a rewinding position (not shown).
As can be seen from FIGS. 4 and 5, the rewinding tube 11 has a flange-like portion 28 projecting radially outwardly from its lower end, with at least one yarn catching notch 30 formed in the flange 28. The radial flanged portion 28 is recessed on its interior to receive a spring element 34, preferably embodied as a snap ring or the like, that partially covers the yarn catching notch 30 at a distance a from the lower edge 35. The distance a should preferably be the same as or greater than the diameter of the yarn to be caught.
In the event of a yarn break below the yarn sensor 4, the trailing yarn end that emerges from the mouth of the yarn guide 5 is not as a rule applied securely flush against the annular interior surface of the yarn cake 10 but instead loosely forms in chord-like segments 36, 37 relative to the previously wound layers of the yarn cake 10. If such a chord-like segment 36 or 37 of a yarn end located on the yarn cake 10 enters the region of the radial flange portion 28 of the rewinding tube 11, then as the spinning pot continues rotating the notch 30 acts as a yarn catching device in which the chord-like yarn segment becomes engaged to be grasped and clamped by the spring element 34, without any necessity for the yarn segment to have been tensioned or otherwise held taut beforehand. Because the spinning pot continues rotating during this yarn end catching operation, a rewinding operation is automatically initiated causing the entire yarn cake 10 deposited in the spinning pot to then be wound in ordered fashion onto the rewinding tube 11 for subsequent unwinding from the tube 11 without loss.
It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof. | A pot spinning machine holds a yarn rewinding tube in ready position during the spinning operation for immediate movement to an operative rewinding position in the event of a yarn break so that the broken end of yarn is not lost by winding onto the yarn cake already formed in the spinning pot and the yarn cake may then be properly rewound. The yarn break is detected with the aid of a yarn sensor which then emits a signal for immediately moving the rewinding tube into the rewinding position and clamping the yarn end. The rewinding operation can begin, even in the absence of a loose end of the yarn, if the yarn has assumed the form of a chord-like yarn segment extending substantially in the circumferential direction against the inner face of the yarn cake deposited onto the inside wall of the pot, which can be grasped and utilized to initiate the rewinding operation. | 3 |
[0001] This application is a continuation in part of U.S. Ser. No. 09/054,709 entitled “MODULAR HUMERAL PROSTHESIS AND METHOD” by Dews, the entire contents of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] During the procedure of a shoulder replacement operation, at least a portion of the proximal section of the humeral shaft will be replaced by a metal prosthesis. This prosthesis will generally consist of two parts: a stem that is mounted into the medullary canal of the humerus, and a head component connected in some manner to the stem. The head component replaces the bearing surfaces of the humerus and articulates with the surface of the scapula to allow the movement of the shoulder.
[0003] Modular humeral prostheses are known. The stem and head component may be supplied in “modular” form, that is, as separate connectable components. Different stem sizes and head sizes in a modular implant design provide the surgeon with some degree of inter-operative flexibility, which facilitates reconstruction of the original anatomy of the patient.
[0004] With a range of stem sizes and a range of head sizes available, the surgeon can choose a particular combination to suit the anatomy of each individual patient without having to stock a large inventory of “integral” or “unitary” humeral prostheses. As used herein, “integral” and “unitary” mean formed in one continuous piece in contrast to the separate connectable components of a modular prosthesis. For example, one patient might require a relatively small head and a relatively long stem. With a unitary prosthesis a wide range of stem lengths would be required for each head size whereas with a modular arrangement a particular head can be used with a range of stem sizes and visa versa.
[0005] Additional variations arise also as a result of individual patients requiring differing angles of inclination of the head relative to the stem and differing offsets between the axis of the head and the axis of the stem. Thus, in one patient the offset may be posterior and in another anterior.
[0006] Various shoulder prostheses are disclosed in European Patent Publication No. EP-A 0 679 375 to Odella dated Sep. 2, 1998; EP-A 0 712 617 to Walch, et al. dated Sep. 29, 1999; French Patent No. FR-A 2 664 809 to Travers dated Dec. 26, 1997; U.S. Pat. Nos. 3,694,820 to Scales, et al. dated Oct. 3, 1972; 3,803,641 to Golyakhousky dated Apr. 16, 1974; 4,045,825 to Stroot dated Sep. 6, 1977; 4,106,130 to Scales dated Aug. 15, 1978; 4,179,758 to Gristina dated Dec. 25, 1979; 4,865,605 to Dines, et al. dated Sep. 12, 1989; 4,919,670 to Dale, et al. dated Apr. 24, 1990; 5,358,526 to Tornier dated Oct. 25, 1994; 5,549,682 to Roy dated Aug. 27, 1996; 5,462,563 to Shearer, et al. dated Oct. 31, 1995 and 5,702,457 to Walch, et al. dated Dec. 30, 1997; and PCT International Patent Publication No. WO 96/17553 to McDaniel, et al. dated Jun. 13, 1996, which are all incorporated herein by this reference.
SUMMARY OF THE INVENTION
[0007] This invention provides a modular prosthesis in which a humeral head, chosen to suit a patient, is attached to a stem chosen to suit the resected humerus of the patient by means of an intermediate connecting member. The prosthesis can accommodate a wide range of variation in, for instance offset and/or angle, in a relatively inexpensive and efficient manner, by accommodating the variations in the intermediate connecting member rather than in the head.
[0008] Additionally, prostheses according to the present invention can include a traditional modular humeral head as well as an eccentric modular humeral head. The eccentric head features a portion that is offset from the radial center of the humeral head that cooperates with the intermediate connecting member. This eccentric head embodiment works in conjunction with the intermediate connecting member, allowing the surgeon even further variations and options during the surgery.
[0009] The modular humeral prosthesis generally comprises a stem adapted to be fitted to a resected humerus, a head adapted to approximate the size and shape of a humeral head, and an intermediate connecting member for connecting the stem to the head. The intermediate connecting member includes two connecting surfaces or other engagement structure. The first connecting surface is adapted to cooperate with a structure forming part of the stem in order to mount the intermediate connecting member to the stem. The second connecting surface is adapted to cooperate with a structure forming part of the head in order to mount the head to the intermediate connecting member. Preferably, the second connecting surface is partially nested with the first connecting surface. The connecting surfaces are preferably surfaces of rotation having axes of rotation, so that they are provided with a full range of rotational motion.
[0010] For example, the first connecting surface or engagement means for mounting the intermediate connecting member on the stem, may have an axis about which the intermediate connecting member can be rotated through 360° relative to the stem and thereafter secured at a selected relative orientation. The second connecting surface or engagement means for mounting the head on the intermediate connecting member may have an axis about which the head can be rotated through 360° relative to the intermediate connecting member and thereafter secured at a selected relative rotation.
[0011] In one embodiment, the axes of rotation of the first and second connecting surfaces are not coincident or collinear, allowing the head to be given a desired offset relative to the stem.
[0012] In another embodiment, the axis of rotation of the first and second connecting surfaces are not parallel, allowing a desired inclination of the head relative to the stem. Furthermore, the first and second connecting surfaces of the intermediate connecting member may be positioned relative to one another to provide a desired separation between the head and the stem. Preferably, the separation or “neck length” between the head and the stem is no greater than 5 mm, but this may vary depending upon surgeon preferences.
[0013] In a further embodiment, the connecting surfaces provide both an offset and an angle of inclination, so that in use, the head is offset and angled relative to the stem.
[0014] Also, the first and second connecting surfaces may each comprise a male or female portion, and the head and stem are provided with corresponding mating portions. The male and/or female portions preferably each have a substantially circular cross-sections, and a substantially self-locking tapered configuration (i.e., a Morse taper). A “Morse taper” is taper that forms an angle providing a self-locking function.
[0015] It is possible for a bore to be provided through the first and second connecting surfaces that extends through the intermediate connecting member, the prosthesis further comprising a fastener inserted through the bore to engage the stem further to secure the intermediate connecting member to the stem.
[0016] In another aspect of the invention, a modular humeral prosthesis kit is provided for replacement of the humeral head of a humerus. The kit generally comprises a stem adapted to be fitted to a resected humerus, a head sized and configured to approximate the humeral head, and a plurality of intermediate connecting members of which one may be selected to connect the stem to the head. Each intermediate connecting member includes a first connecting surface for mounting the intermediate connecting member on the stem, and a second connecting surface for mounting the head on the intermediate connecting member. The plurality of the intermediate connecting members of the kit include:
A. at least one intermediate connecting member in which the first and second connecting surfaces share an axis of rotation; B. at least one intermediate connecting member in which the first and second connecting surfaces are offset from each other; and C. at least one intermediate connecting member in which the first and second connecting surfaces are inclined at an angle relative to each other.
[0020] In another embodiment, the plurality of intermediate connecting members of the kit include:
A. at least one intermediate connecting member in which the first and second connecting surfaces have generally parallel and coincident central axes; B. at least one intermediate connecting member in which the first and second connecting surfaces have generally parallel but not coincident central axes; C. at least one intermediate connecting member in which the first and second connecting surfaces have an angle of inclination between one another that is different than the angle of inclination between the first and second connecting surfaces of another intermediate connecting member of the kit; and D. at least one intermediate connecting member in which the first and second connecting surfaces are separated by a different neck length than the neck length separating the first and second connecting surfaces of another intermediate connecting member of the kit.
[0025] The specifications for the plurality of intermediate connecting members described above may be met by combining features in some of the intermediate connecting member of the kit. For example, two intermediate connecting members may have different neck lengths, angles of inclination and offsets or zero offset.
[0026] Preferably, the first connecting surface of each intermediate connecting member has an axis about which the intermediate connecting member can be rotated through 360° relative to the stem and thereafter secured at a selected relative orientation, and the second connecting surface of each intermediate connecting member has an axis about which the head can be rotated through 360° relative to the intermediate connecting member and thereafter secured at a selected relative rotation.
[0027] Preferably, the first connecting surface of each intermediate connecting member comprises a female portion, and the stem is provided with a corresponding mating male portion, and the second connecting surface comprises a male portion having the first connecting surface nested therein, and the head is provided with a corresponding mating portion, such as a female cavity. Most preferably, the male and female portions each have a substantially circular cross-section, and a substantially self-locking tapered configuration (i.e., a Morse taper).
[0028] In a further embodiment, the surgeon is provided with the option of using a traditional humeral head, having its corresponding mating portion at the approximate center of the radius of the humeral head, or using an eccentric humeral head, having its corresponding mating portion offset from the center of the radius of the humeral head.
[0029] According to other aspects of the invention, methods of replacing a humeral head in a patient generally comprise:
(a) Resecting the proximal end of the humerus to remove the head and expose the medullary canal of the humerus; (b) Inserting the stem of a prosthesis into the medullary canal of the resected humerus, the prosthesis being modular and comprising:
(i) a stem; (ii) an eccentric humeral head; and (iii) one of a plurality of intermediate connecting members for connecting the stem to the head; each intermediate connecting member including:
a first, female, connecting surface forming a cavity that is adapted to receive a structure that protrudes from the stem in order to mount the intermediate connecting member to the stem; and a second, male, connecting surface adapted to be received in a cavity in the head in order to mount the head to the intermediate connecting member, the second connecting surface at least partially nested with the first connecting surface; the plurality of intermediate connecting members including at least some members having different angles of inclination between their first and second connectors;
(c) selecting a particular intermediate connecting member to provide a desired angle of inclination of the head relative to the humerus; and (d) mounting and locking the intermediate connecting member to the stem, and mounting and locking the intermediate connecting member to the head, the mounting and locking of the intermediate connecting member to the stem and head imparting any desired angle of inclination of the head relative to the humerus.
[0041] The plurality of intermediate connecting members may include intermediate connecting members having different neck lengths separating the first and second connecting surfaces, and the methods further comprise selecting an intermediate connecting member to provide a desired separation between the head and the stem.
[0042] The surgeon will still need her traditional range of head sizes and stem sizes and lengths. However, the surgeon does not need additional heads or stems to provide a particular orientation of the head or a particular offset for the head, although the surgeon may prefer to use the eccentric head option described herein. Thus, while a range of intermediate connecting members are required to be available to choose particular offsets and orientations, those intermediate connecting members are relatively inexpensive compared with the normally considerable cost of the highly sophisticated head component.
[0043] Also, it is an advantage of the invention that the surgeon can choose quite independently of one another the three component parts. Thus, the surgeon does not have to be concerned with questions of offset and orientation when selecting the right head size, except to the extent that she prefers to use an eccentric head. The same is true as regards the stem: the surgeon can choose the correct stem to fit the medullary canal in the humerus and so give a long lasting and secure joint between the stem and the bone. Having selected these components, the surgeon can, quite independently, decide on the particular offset and/or orientation of the head relative to the stem and select an intermediate connecting member accordingly. The surgeon is, therefore, able to match the modular prosthesis used to the original anatomy of a particular patient. Because a shoulder joint is enclosed and surrounded by soft tissue, it is preferable (but not necessary) that the spacing between the end of the stem and the head be kept to a minimum, e.g. no greater than 5 mm.
[0044] The typical surgical procedure for the implantation of a humeral prosthesis includes the determination of the longitudinal axis of the humerus, drilling a hole in the proximal margin between the head and the tuberosity in line with this, then inserting a starter reamer or broach, and developing a bore hole along the longitudinal axis of the humerus. Next, this bore hole can be enlarged by using progressively larger reamers or broaches, until the surgeon determines that the reamer or broach being used is the largest possible fit into the available cavity without the excessive removal of cortical bone. Then, the head is accurately removed from the proximal portion of the humerus, and a flat angled face is prepared on the proximal portion of the humerus, usually along the line of the anatomical neck, by means of a resection guide.
[0045] The cavity thus prepared, the trial stem can be introduced. At this stage, the surgeon is able to determine the amount of anteversion that is appropriate for the patient. Once in place, the head measurement instrument can be attached, and the trial head attached to this. This head measurement instrument allows the accurate placement of the head in a number of different positions so that the surgeon can assess which position best suits the anatomy of the patient. Once determined, the surgeon can, in one aspect of the invention, read off the specific orientation of the head from a scales or indicia on the instrument; this determines which intermediate connecting member is to be used with the definitive implant.
[0046] It is not possible to provide an infinite number of intermediate connecting members so as to cover every possibility of adjustment. In practical terms, therefore, one provides a range of intermediate connecting members in incremental sizes to provide a range of discrete adjustments in just the same way that a discrete number of heads and stems are provided. However, because the connecting surfaces allow the relative rotation of the components, one can with a single intermediate connecting member choose an amount of offset and that amount can be positioned on a locus throughout 360°. The same, of course, is true as regards the inclination of the axis of the head relative to the stem.
[0047] Another reason that having a range of intermediate connecting members is helpful to the surgeon is because it allows the surgeon to replace the intermediate connecting member without removing the entire stem. For example, in a revision surgery, the surgeon may want to change the angulation or the offset of the head member with respect to the stem without removing the stem. Providing the surgeon with an intermediate connecting member allows the surgeon to use the intermediate connecting member to angulate the head with respect to the stem or offset the head with respect to the stem without requiring a whole new implant. The surgeon can use the intermediate connecting member to change inclination or offset so that the head will correspond appropriately to the stem.
[0048] In a preferred embodiment of the invention, the intermediate connecting member is available in a discrete number of sizes, each size providing an incremental increase in the separation between the two connecting surfaces. Thus, the surgeon is provided with a variety of parts from which to choose in order to approximate best the patient's original anatomy by selecting a part that will provide the closest approximation of the original separation between the humeral head and the humeral stem.
[0049] It is preferred that the second connecting surface be located at the center of the base of the humeral head. Thus, in this embodiment, the relative rotational placement of the head component has no effect in altering the angle of inclination of the head or the axial offset of the head in relation to the stem or even the separation between the head and the stem. If the surgeon desires that the humeral head itself should have an offset, she may use an eccentric head in conjunction with the intermediate connecting member. It is not essential that the second connecting surfaces be of circular cross-section although this is preferred. This provides the advantage that fewer of the expensive head components are required to achieve this range of variables. Naturally the head will have to be provided in a number of incrementally varying sizes to fit the needs of each individual patient's scapula or glenoid prosthesis. Additionally, in an alternate embodiment, there are also provided eccentric heads in a number of incrementally varying sizes. The portion of the connecting surface forming part of the intermediate connecting member can both be male or alternatively one can be male and the other female.
[0050] It is further preferable that the connecting surfaces will each be of a substantially cylindrical shape, whether male or female, and therefore allow the intermediate connecting member to be rotatable relative to the stem and the head rotatable relative to the intermediate connecting member before securement. To fix one part relative to the other the cylinders of the male and female portions are preferably of the Morse taper type. This fixing may be supplemented by a screw or other fastener fixation. In order to satisfy the criterion for strength, it is desirable that the intermediate connecting, member be formed in one piece. It is, however, within the scope of this invention that the intermediate connecting member be formed from a plurality of pieces.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] Embodiments of the invention will now be described by way of ‘example and with reference to the accompanying schematic drawings, in which:
[0052] FIG. 1 is an exploded side elevation of a modular humeral prosthesis according to the invention;
[0053] FIG. 2 is the assembled prosthesis of FIG. 1 ;
[0054] FIGS. 3-7 are various intermediate connecting members according to the invention;
[0055] FIG. 8 is an exploded side elevation of a second embodiment of the modular humeral prosthesis according to the invention; and
[0056] FIGS. 9-13 are various intermediate connecting members according to another embodiment of the invention.
[0057] FIGS. 14-16 are various intermediate connecting members according to a further embodiment of the invention.
[0058] FIG. 17 is a bottom plan view of a preferred embodiment of an eccentric head according to the invention.
[0059] FIG. 18 is a bottom plan view of the eccentric head of FIG. 17 , having a milled trench.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0060] The stem 10 shown in FIG. 1 is available in a number of different sizes to match the size to which the medullary canal 12 has been reamed or broached. The shaft of the stem 14 is designed to contact the previously reamed or broached medullary canal 12 and extend into the remaining humerus to prevent any undesired movement of the stem 10 .
[0061] The stem 10 may be prevented from rotating by the use of fins 16 located at the neck of the stem 10 . These fins 16 are wedged into the proximal position of the humerus to prevent any undesired movement of the stem 10 and offer some additional support to the face 18 of the stem 10 . The face 18 of the stem 10 fits onto the previously prepared face of the humerus 20 , and is designed so that the angle of the face 18 is roughly equal to that of the anatomic neck of the humerus. Coassigned U.S. patent application Ser. No. 08/946,758, filed Oct. 8, 1997, and PCT International patent application No. US97/18207, filed Oct. 8, 1997, both by Michel Mansat et al disclose a shoulder prosthesis with fins, and are incorporated herein by reference.
[0062] The humeral head 22 is designed to articulate with the scapula or glenoid prosthesis (not shown). The head 22 replaces the articulating surface of the humerus and is largely hemispherical in shape. A variety of sizes of head 22 are provided to complement the patient's scapula or glenoid prosthesis. The articulating surface of the head 22 is highly polished to reduce friction, hence wear, on the scapula or glenoid prosthesis.
[0063] Based on proximal humeral morphology, the humeral head center of the preferred embodiment is generally medialized and offset posteriorly from the humeral canal. In fact, there is about a 3 mm posterior offset in an average individual. In order to provide optimal proximal humeral bone coverage, it is useful to provide the surgeon with the option of using an eccentric head 200 , shown in FIG. 17 .
[0064] As with a traditional humeral head, eccentric humeral head 200 is also designed to articulate with the scapula or glenoid process. However, instead of having a centered mating portion, head 200 according to the preferred embodiment has an eccentric mating portion 202 . Eccentric mating portion 202 is not coaxial with the head, i.e., it is offset from the center of the humeral head articular radius. This eccentricity helps to align the proximal humeral stem with the glenoid, providing a shift in the normal anatomy.
[0065] Eccentric humeral head 200 is shown as having a female taper that is offset from the center of the humeral head articular radius. It should be understood, however, that mating portion 202 may be any connecting structure, such as a male mating portion, a tapered mating portion (whether or not male), and the like. The essence of the invention is that the humeral head itself displays eccentricity. This eccentricity may range from 1 mm to 5 mm. If eccentric head 200 is used in conjunction with an intermediate connecting member, it allows the surgeon to achieve more options to fit various patient geometries.
[0066] The variation in patient anatomy, inclination angle, retroversion, and posterior offset of the humeral head necessitate the need for a multitude of intra-operative adjustments. Eccentric head 200 allows the surgeon during surgery to adjust for inclination, retroversion, and/or eccentricity. During intra-operative trialing, which the surgeon performs in order to place the correct amount of tension on the soft tissue and supporting tendons, the proper humeral head size (height and diameter) is initially selected. The eccentric humeral head 200 enables the surgeon to adjust the humeral head prosthesis in order properly to position the humeral head in an optimum position with respect to the glenoid articular surface, as well as with respect to the tuberosity attachment site. The ability to adjust the eccentricity in the plane of the selected inclination angle along with the ability to adjust retroversion is a distinct advantage in achieving optimal joint balancing and increased range of motion.
[0067] For example, if the surgeon wishes to vary the inclination angle or provide an offset of the head with respect to the stem, use of an intermediate connecting member, described below, can help achieve this configuration. However, if the surgeon wishes to alter the retroversion angle of the center of the head with respect to the glenoid, the use of eccentric head 200 helps achieve this configuration. An eccentric head used in conjunction with an intermediate stem member allows the surgeon to vary inclination, retroversion, eccentricity and offset, providing the surgeon with an increased range of usability and possibilities to fit various patient features or irregularities.
[0068] Of course, eccentric head 200 may be employed with or without an intermediate connecting member. In other words, the eccentric head described herein may be used coupled directly to the humeral stem. It may also be used in conjunction with an intermediate connecting member that has an offset, that provides an angle, or a combination of both or neither. Additionally, eccentric head 200 may be used as an actual implant or as part of a trialing system or method. An exemplary trialing method is described in copending Provisional Application U.S. Ser. No. 60/201,503 to Hartdegen filed May 3, 2000, Attorney Docket Number 10557/200809, incorporated herein by reference.
[0069] In a further embodiment, as shown in FIG. 18 , eccentric head 200 has a female mating portion and trench 204 or groove defining mating portion 202 . Trench 204 is any groove, indentation, or removed portion that may be milled, molded or otherwise formed. It is located circumferentially around and substantially surrounds or otherwise defines mating portion 202 . Trench 204 may extend the entire circumference of the inside of the humeral head, or it may be divided by distraction slots 206 as shown in FIGS. 17 and 18 .
[0070] Trench 204 preferably extends to the edge of the modular humeral head. Trench 204 may be any depth, but preferably extends to the bottom of the taper, approximately ten millimeters, though it is possible to provide a shallower trench 204 . It is preferred that trench 204 extend to the depth at which the head and stem engage when in use. Put another way, trench 204 should extend to the depth where modular humeral head fully cooperates with the end of intermediate connecting member or stem when in use.
[0071] Providing a trench 204 on eccentric head 200 imparts a number of advantages. It provides increased distraction forces, so that when the surgeon impacts the head on the stem, the head provides superior locking forces with respect to the stem taper or intermediate connecting portion. It should be noted that trench 204 may achieve the described advantages if provided on either eccentric head 200 or on a traditional humeral head. It should also be noted that any head having a trench 204 may be used with or without an intermediate connecting member. For purposes of this document, reference to head 22 also includes a reference to eccentric head 200 , a head with a trench 204 (whether traditional or eccentric), or both.
[0072] In use, it is believed that trench 204 allows the female taper to expand, creating hoop stress, which are tensile stresses along circumference of taper/lock interface. The increased tensile stresses help hold the two tapers together and thereby increase distraction forces between the two mating surfaces.
[0073] Without limitation to any theory, it is believed that the trench 204 allows taper to receive and seat further the portion with which it connects (whether it be the connecting surface of intermediate connecting member or the stem). As the taper expands, the portion with which it connects can seat even further and deeper into the taper, providing increased locking forces. To the contrary, a solid head not having trench 204 does not provide this benefit because there is no room for the taper to expand. Trench 204 on head 200 strengthens the attachment of the head to a corresponding component.
[0074] Currently, other device manufacturers offer only eccentric heads. However, consideration must be given to the locking device when the center line of the Morse tapers are not co-axial. The ability of the eccentric head to provide a substantial lock with respect to the stem taper or intermediate member has not been considered in current designs. This invention provides, in preferred embodiments, a superior locking means by the presence of a trench 204 , which provides an increase in taper locking strength. The addition of the trench 204 provides the opportunity to provide up to at least 5 mm of eccentricity, an option that no other system currently provides.
[0075] Because of the increased distraction forces that are required to remove the head from the stem, eccentric head 200 is shown having distraction slots 206 . Distraction slots 206 provide an opening, which allows the surgeon to use an osteotome or other instrument to apply a lever- type motion to more easily remove the head from the stem.
[0076] An intermediate connecting member 24 as shown in FIG. 1 has first and second male tapers 26 and 28 of the “Morse taper” type. Once pushed together two Morse taper parts tend to stay together. The first taper 26 is designed to connect with the stem 10 and the second taper 28 with the head 22 . The tapers 26 and 28 are aligned in generally opposite directions for mating with a female taper 30 of the stem 10 and a female taper 32 of the head 22 .
[0077] The first male taper 26 may also be held onto the female taper 30 of the stem 10 by means of a locking screw 34 , which fits into a counter-bored hole 36 in the intermediate connecting member 24 . The axis of this counter-bored hole 36 is aligned along the central axis of the taper 26 and the screw fits into this counter-bored hole 36 and locates into a threaded hole 38 in the stem 10 .
[0078] The male tapers 26 , 28 of the intermediate connecting member 24 can be securely connected with the respective female tapers 30 , 32 of the stem 10 and head 22 , which are also of the Morse taper type and match the tapers of the intermediate connecting member 24 by applying an external force, to form an interference fit between the mating tapers 24 and 30 , and 26 and 32 , as shown in FIG. 2 .
[0079] The first and second male tapers 26 and 28 constitute one embodiment of the first and second connecting surfaces of the intermediate connecting member 24 . Alternatives include other connecting or mating parts that define the relative orientation and position of the head 22 and the intermediate connecting member 24 or the stem 10 and the intermediate connecting member 24 . For example, the first and/or second male tapers 26 and 28 could be replaced by female tapers (not shown) and the female tapers 30 and 32 of the stem 10 and/or head 22 replaced by male tapers (not shown).
[0080] There can be a large variety in the shape, size and orientation of human humeral bones and therefore it is desirable to tailor the humeral prosthesis to suit each individual case. The various designs of intermediate connecting members of the present invention provide a considerable range of different head positions and orientations relative to the humeral stem that can be selected and connected inter-operatively.
[0081] The position of the head 22 can be varied by using different intermediate connecting members 24 as are appropriate in each individual case. Various designs of intermediate connecting members 24 a - a are illustrated in FIGS. 3 to 7 .
[0082] In each of these cases the intermediate connecting member 24 a - e has the same elements and is joined to the stem 10 and head 22 as described above.
[0083] One configuration of an intermediate connecting member 24 a is illustrated in FIG. 3 . In this configuration, the first male taper 40 and the second male taper 42 are axially aligned with minimum separation or “neck length” 44 between them. The design of this intermediate connecting member 24 a matches the anatomical. design of some patients' original humerus.
[0084] For other patients, a larger separation between the head 22 of the humeral prosthesis and a fixed point on the stem 10 is more appropriate. To meet this requirement, the intermediate connecting member 24 b of FIG. 4 is used. In this design, a portion of the intermediate connecting member 24 b between the two tapers 50 and 52 is available in a number of incrementally different sizes to allow the surgeon to select the appropriate separation or “neck length” 54 between the tapers 50 and 52 , and hence the separation between the head 22 and stem 10 of the prosthesis.
[0085] The anterior or posterior offset can be simulated using the design of intermediate connecting member 24 c as shown in FIG. 5 to mimic offsets 66 that can naturally occur in the humerus. In this design, the central axes of the first and second male tapers 60 and 62 are parallel and offset from one another as illustrated at 66 . The second male taper 62 is counter-bored at an off-center position (e.g., compare bore 68 or FIG. 5 with bores 48 and 58 of FIGS. 3 and 4 ). This allows the head 22 to be attached on a parallel but not coincident axis to the first male taper 60 , and thus to the female taper 30 of the stem 10 . Again, this design is available in a number of incrementally different offsets 66 so the surgeon can select the most appropriate intermediate connecting member 24 c for each individual patient inter-operatively.
[0086] The angle of inclination α of the humeral head relative to the axis of the humeral stem can vary from patient to patient. The intermediate connecting member 24 d can simulate this orientation. The design shown in FIG. 6 comprises a portion of the intermediate connecting member 24 d that has a generally wedge shaped design. The surgeon will be able to select the wedge-shaped intermediate connecting member 24 d from a range of intermediate connecting members 24 d having incremental difference in the inclination angle a as shown in FIG. 6 , to best fit each individual patient. Due to the wedge-shape, the central axes of the first and second male tapers 70 and 72 of this design are offset from parallel by an angle equal to the inclination angle α.
[0087] Any of the features of intermediate connecting members 24 a - d illustrated in FIGS. 1 to 6 can be combined to provide the desired variation in neck length 44 , 54 , 84 anterior or posterior offset 66 , 86 or angular inclination a to best suit each individual patient's anatomy.
[0088] FIG. 7 shows an intermediate connecting member 24 e that includes a combination of the angular inclination α as described in FIG. 6 , the anterior/posterior offset 86 as depicted in FIG. 5 , and the taper separation 84 as illustrated in FIG. 4 .
[0089] In the above embodiments, the male members of the two connecting surfaces are provided by the intermediate connecting member 24 a - e . In an alternative embodiment one or both -of the two connecting surfaces provided by the intermediate connecting member may comprise female portions. For example, FIG. 8 illustrates a second embodiment of the modular humeral prosthesis 100 of the invention similar in many respects to the first embodiment shown in FIGS. 1-7 . Differences include the provision of a male tapered connecting portion 102 on the stem 104 , and a female tapered connecting portion 106 on the intermediate connecting member 108 .
[0090] Male connecting portion 102 and female connecting portion 106 are designed for substantially self-locking mating, and preferably have a circular cross section The self-locking function may be accomplished by providing a “Morse taper” on the male and female connecting portions 102 and 106 . The female connecting portion 106 constitutes a second embodiment of the first connecting surface of the intermediate connecting member 108 .
[0091] Optionally, a fastener 110 may be inserted through a bore 112 through the intermediate connecting member 108 and into engagement with a bore 114 in the stem 104 to further secure the female connecting portion 106 of the intermediate connecting member 108 on the stem 104 . T Fastener 110 and the bore 114 are provided with interlocking threads. As an alternative embodiment, the male and female connecting portion 102 and 106 could be provided with a non-self-locking configuration; in which case the fastener 110 or another locking mechanism would take on a greater importance.
[0092] As is the case with the first embodiment, the head 114 of the second embodiment is provided with a female connecting portion 116 , and the second connecting surfaces of the intermediate connecting member 108 comprises a male connecting portion 118 . The female and male connecting portions 116 and 118 are also preferably provided with a self-locking tapered configuration, i.e., a Morse taper.
[0093] FIGS. 9-13 illustrate various intermediate connecting members 108 a - a for use in the prosthesis 100 . FIGS. 9 and 10 illustrate two intermediate connecting members 108 a and 108 b providing two different separations 120 and 122 . In this respect, intermediate connecting member 108 a is similar to intermediate connecting member 24 a of the first embodiment ( FIG. 3 ) due to the minimal separation 120 or 44 , and intermediate connecting member 108 b is similar to intermediate connecting member 24 b of the first embodiment ( FIG. 4 ) due to the greater separation 122 or 54 . Both intermediate connecting member 108 a and 108 b show a zero inclination angle and a zero offset.
[0094] FIG. 11 illustrates another intermediate connecting member 108 c having, like member 108 a , minimal separation. Intermediate connecting member 108 c , however, has a non-zero offset 124 . This non-zero offset 124 is accomplished by displacing or offsetting the central axis or axis of rotation of the female locking portion 126 relative to the central axis of axis of rotation of the male locking portion 128 by the offset 124 . In this respect, the intermediate connecting member 108 c is similar to the intermediate connecting member 24 c of the first embodiment ( FIG. 5 ).
[0095] FIG. 12 illustrates yet another intermediate connecting member 108 d having, like member 108 a , minimal separation and zero offset. Intermediate connecting member 108 d , however, has a non-zero inclination angle β. Inclination angle β is similar in function and preferred magnitude to the inclination angle α discussed with respect to the first embodiment (e.g., FIG. 6 ).
[0096] FIG. 13 illustrates an intermediate connecting member 108 e having a non-zero separation 130 , a non-zero offset 132 and a non-zero inclination angle β. In this respect, intermediate connecting member 108 e is similar to intermediate connecting member 24 e of the first embodiment ( FIG. 7 ).
[0097] FIGS. 14-16 are various intermediate connecting members corresponding to FIGS. 11-13 , but showing the tapered locking portions in more detail.
[0098] One consequence of the design of the second embodiment of the prosthesis is that the male connecting portion 118 may have a length extending into the intermediate connecting member, e.g., 108 a , a distance sufficient that it is received both in the intermediate connecting member 108 a and the void defined by the female connecting portion 116 of the head 114 . This is accomplished without any direct engagement between the male connecting portion 118 of the stem 104 and the female connecting portion 116 of the head 114 .
[0099] Other embodiments, which are not illustrated in the drawing, include (1) the first connecting surfaces comprising a male connecting portion and the second connecting surfaces to comprising a female connecting portion, and (2) both the first and second connecting surfaces comprising female portions.
[0100] In summary, at least one advantage of providing an eccentric humeral head along with an intermediate connecting member having an angulation and/or inclination is that although the intermediate connecting member can change the medial offset (offset from glenoid to humeral canal), the eccentric head helps align the humeral head with the glenoid (to account for natural offset in anatomy.) In other words, even though the intermediate connecting member can change the retroversion angle, the humeral head may still not be in center of glenoid. The eccentric head helps provide this alignment. Put another way, the intermediate connecting member provides the ability to adjust the inclination angle and retroversion angle. The addition of eccentric head 200 provides the surgeon with ability to adjust for the posterior offset (i.e., eccentricity) of the humeral head in the plane of the adjusted humeral head.
[0101] As various changes could be made in the above constructions and methods without departing from the scope of the invention as defined in the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense. | A modular humeral prosthesis for replacement of the humeral head of a humerus. The prosthesis generally comprises a stem to be fitted to a resected humerus; a head sized and configured to approximate the humeral head; and an intermediate connecting member for connecting the stem to the head. The intermediate connecting member provides a desired angle of inclination or offset between stem and head. The head may be a traditional humeral head, or it may be an eccentric humeral head, with its mating portion being offset. The head may also comprise a groove or milled trench at least partially surrounding or otherwise defining mating portion. Also disclosed is a modular humeral prosthesis kit comprising a variety of different intermediate connecting members that may be selected to tit the prosthesis to the patient, and a method of replacing a humeral head in a patient. | 0 |
BACKGROUND OF THE INVENTION
This invention relates generally to the filed of cooling beverages, and in particular to the use of removable cooling elements that may be integrated into various beverage containers. Such cooling elements are removable to permit them to be placed into a refrigerator freezer and reused.
Perhaps the most common method to cool beverages is with ice cubes. Another way to frost a glass in a freezer. However, there are many problems associated with these methods. For example, ice cubes dilute the beverage and can alter the taste of the beverage. Ice cubes may also be contaminated when touched, such as when placing them into the beverage. As another example, when frosting a glass in the freezer, the frost can be contaminated by other products in the freezer, causing an odor. As a further example, the beverage may be contaminated by the water used to make the ice.
Hence, this invention is related to devices and techniques for cooling beverages which greatly reduces or eliminates such drawbacks.
BRIEF SUMMARY OF THE INVENTION
In one embedment, the invention provides a beverage container that comprises a vessel having an interior that is adapted to hold a beverage. The vessel has a closed bottom end and an open top end, with the bottom end defining a cavity that is fluidly sealed from the interior of the vessel. The beverage container also includes a cooling element that is configured to fit within the cavity. The beverage container further includes a base comprising a bottom member and a stem extending vertically upward from the bottom member. The base includes a connector that is configured to be coupled to the bottom end of the vessel and to enclose the cooling element within the cavity. In this way, a beverage held within the vessel may be cooled by the cooling element that is fluidly sealed from the interior of the vessel. As such, the beverage may be cooled without contamination from the cooling element. Further, the cooling element may easily be removed and replaced with a fresh cooling element whenever needed.
In one aspect, the connector comprises a threaded end on the stem. The cavity may also include a threaded section so that the threaded end may be screwed up into the cavity using the threaded section. In this way, the exterior of the beverage container may contain a smooth morphology to make the container more aesthetically pleasing. At the same time the beverage container may easily be separated into its component parts for cleaning, replacement of the cooling element, or the like.
In another aspect, the cavity may be generally cylindrical in geometry and extend vertically upward into the interior of the vessel. With such a configuration, the cooling element may comprise a cylinder that is filled with a cooling substance. In a further aspect, both the connector and the vessel may be constructed of various materials, such as glass, hard plastics, glass coated with a hard plastic, and the like.
The beverage containers of the invention may be configured into a wide variety of shapes while still providing a suitable cooling element. For example, the vessel may be in the shape of a mug, a wine glass, a martini glass, a tumbler, a stein glass, a margarita glass, a champagne glass, and the like.
In one particular embodiment, the bottom end of the vessel may define a generally hemispherical cavity that is fluidly sealed from the interior of the vessel. With such configuration, a generally hemispherical cooling element may be provided to fit within the cavity. In this way, the base may be coupled to the bottom end of the vessel to enclose the cooling element within the cavity. The use of a generally hemispherical cooling element is advantageous in that it maximizes the surface area available for heat transfer. Such a cooling element is also particularly useful in beverage containers that have the shape of a tumbler, mug, or the like because the generally hemispherical cavity fits nicely within the interior of the vessel. Conveniently, the vessel may include threads while the bottom end of the vessel also includes threads to permit the base to be screwed into the vessel.
Another feature of the invention is that it may include one or more trays having a plurality of holding regions for holding the cooling element. In this way, the tray may be placed into a freezer to simultaneously cool multiple elements.
In one aspect, the tray may include a plurality of recesses that are integrally formed in the tray to define the holding regions. The recesses may be in the shape of the cooling element so that they may easily fit within the recesses. For example, the recesses may be semi-cylindrical, hemispherical, and the like.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of a beverage container according to the invention.
FIG. 2 is an exploded side view of the container of Fig. 1 .
FIG. 3 is an exploded side view of another embodiment of a container according to the invention.
FIG. 4 is a side view of another embodiment of a container according to the invention.
FIG. 4A is an exploded cross sectional side view of the container of FIG. 4 .
FIG. 5 is a side view of still another embodiment of a beverage container according to the invention.
FIG. 6 is a side view of yet another embodiment of a beverage container according to the invention.
FIG. 7 is a side view of one particular embodiment of a beverage container according to the invention.
FIG. 8 is a side view of another embodiment of a beverage container according to the invention.
FIG. 9 is a side view of a further embodiment of a beverage container according to the invention.
FIG. 10 is a side view of yet a further embodiment of a beverage container according to the invention.
FIG. 11 is a side view of still a further embodiment of a beverage container according to the invention.
FIG. 12 is a top view of one embodiment of a tray for holding cooling elements according to the invention.
FIG. 13 is a top view of another embodiment of a tray for holding cooling elements according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The invention provides various beverage containers that may be used with removable and reusable cooling elements. The containers each include a vessel for holding the liquid and a cavity for holding the cooling element. The cavity is sealed from the interior of the vessel but also extends up into the vessel to provide a cooling effect. The cavity may have a variety of shapes configured to maximize heat transfer away from the liquid. Such shapes may include cylindrical, hemispherical, pyramid shaped, arcuate, square, triangular and the like. The cavity may conveniently have a shape that is similar to the cooling element, although that is not necessary. The wall thickness may also be minimized to maximize heat transfer. The cooling element may contain any substance that can be cooled and serve to absorb heat. Examples include water, gels, Blue Ice®coolant, any non-toxic re-freezable substance, and the like. Alternatively, the cooling element may be a solid substance, such as a metal rod, a piece of ice, or the like. The cooling element may be held in the cavity by a base that has one or more connectors to connect the base to the vessel. Examples of connectors include threads, clips, snaps, screws, press fits and the like. The base may be screwed, twisted, locked or snapped into place. One advantage of using threads is that the vessel may be coupled to the base utilizing relatively few threads. In this way, the two components may be locked together using a single twist. Further, such threads permit the two components to be easily unscrewed, even when the vessel is filled with liquid so that the cooling element may easily be replaced. Few threads also reduce the changes of having the vessel or the base break. Further, with few threads, the beverage container remains symmetrical when assembled, while still being easy to fit together.
Hence, the invention provides a removable cooling element for cooling beverages that may be placed into a regular refrigerator freezer between uses. The removable device when frozen may be placed into an upper portion of the vessel, and a bottom portion may then be attached to the upper portion. The device easily fits into the vessel, which may be constructed of a wide variety of materials, such as glass, plastic or the like. The base of the beverage container may be tubular, cubical, semicircular, pyramidal, or the like, and may be connected to the bottom of the vessel by a stem or end portion that attaches to the bottom of the vessel and seals in the cooling element. When threads are used, they may be constructed of a hard plastic or glass with a hard plastic coating. As another example, one of the threaded elements may be a hard plastic while the other is made of glass, or both may be of a hard plastic. The vessels may be made of glass, plastic, a disposable plastic, or the like. As one specific example, the male threading may be on the base or stem and may be constructed from a hard plastic or glass with a hard plastic coating on a glass stem. Such materials serve to seal the cooling device into the integrated vessel and base to cool the beverage without ever contacting it. As such, the cooling device may be replaced even while the fluid is in the vessel to provide additional cooling.
The cooling element may also be made of a hard plastic, and the re-freezable substance may be of any color. Similarly, the vessel may also be of any color.
When the cooling device is removed, it may be washed and then kept in the freezer in an appropriate cooling tray. The tray may have regions that are shaped to hold the particular cooling element. Because the removable cooling element is never in contact with the interior of the vessel, it is always hygienic.
Such a system provides a variety of advantages. For example, as just described, the beverage is hygienically cooled using a reusable cooling device that never contacts the beverage. The cooling elements fit neatly into a tray and take up little room in the freezer, usually less than an ordinary ice tray.
Further, the beverage container may be separated into parts to facilitate washing. For example, the stem may be separated from the vessel and separately placed into a dishwashing machine with a reduced risk of being broken.
The beverage container may also come in an assortment of colors to make identification of the container simple, thus resulting in less chance of the spreading of germs by drinking from another's glass. Different colors may also be used for the cooling element, the fluid within the cooling element and the cavity used to hold the cooling element.
The extension into the interior of the vessel takes up extra volume. In this way, restaurants and bars may increase their profits per drink.
The beverage also does not get diluted with melting ice, and there is no contamination from the ice/odors or impurities in the water. This is also true with frosted glasses, where the frost can have odors or contamination from the water used to make frost.
Also, since no ice cubes are placed into the beverage, there is no chance of contamination from a person's hand used to place the ice into the beverage. In fact, no human contact with the beverage is ever experienced.
Referring now to FIG. 1, one embodiment of a beverage container 10 will be described. Container 10 comprises a base 12 and a vessel 14 having an open top end 16 and a closed bottom end 18 . Formed in bottom end 18 is a cavity 20 that extends up into the interior 22 of vessel 14 . Cavity 20 is cylindrical in geometry and is sized to receive a cylindrical cooling element 24 . The bottom of cavity 20 has threads 26 for receiving a threaded end 28 of a stem 30 that is part of base 12 . In this way, cooling element 24 containing a cooling substance 25 may be inserted into cavity 20 , and threaded end 28 of stem 30 may be screwed into threads 26 to completely seal cooling element 24 within cavity 20 . One advantage of using internal threads within cavity 20 is that a continuous smooth surface is provided at the interface between vessel 14 and stem 30 . As such, container 10 has the appearance of a traditional wine glass, except for the presence of cooling element 24 that extends into interior 22 . However, this has the advantage of reducing the volume of interior 22 so that restaurants and bars can reduce the amount of beverages served while still charging the same amount.
Another advantage is that the cooling element 24 is almost entirely exposed to interior 22 to maximize heat transfer. Further, since cooling element 24 is sealed from the beverage, no contamination of the beverage by a coolant occurs. Container 10 is also aesthetically pleasing and can be fashioned in essentially any shape or configuration, including conventional shapes and designs as described hereinafter.
In use, cooling element 24 is placed into a cold location, such as a refrigerator or freezer. When ready to pour a beverage, cooling element 24 is removed and placed into cavity 20 . Threaded end 28 is then screwed into cavity 20 until it is unable to turn and a smooth surface at the joint is formed. A beverage is then poured into vessel 14 where it is cooled by cooling element 24 . At any time, base 12 may be unscrewed and cooling element 24 replaced with another one.
Referring now to FIG. 3 another embodiment of a beverage container 40 will be described. Container 40 is essentially identical to container 10 except that container 40 is a martini glass and has a different shaped vessel 42 . As such, container 40 is labeled with the same reference numerals for elements that are the same as those used with container 10 . When stem 30 is screwed into cavity 20 , vessel 42 has a conical shape that is continuous at the interface between vessel 42 and stem 30 .
FIGS. 4 and 4A illustrate a beverage container 50 in the shape of a mug. Container 50 comprises a vessel 52 having an open top 54 and a closed bottom 56 to form an interior 58 . Extending up onto the interior 58 is a hemispherical cavity 60 to hold a hemispherical cooling element 62 . This shape maximizes the coolable surface wherein interior 58 to maximize cooling. Conveniently, a handle 64 may be coupled to vessel 52 .
Bottom 56 includes internal threads 66 to mate with threads 68 on a base 70 having an outer edge 72 . After cooling element 62 is placed into interior 58 , base 70 is screwed into bottom 56 until edge 72 is flush with vessel 52 as shown in FIG. 4 . Hence, container 50 has the shape of a traditional mug while also containing a cooling element that is configured to maximize heat transfer. In addition, container 50 includes all of the benefits of the other containers described herein.
FIGS. 5-10 describe various other embodiments of beverage containers that are constructed in a manner similar to the other containers described herein. As such, the containers in FIGS. 5-10 are labeled with similar elements followed by “a” through “g”. FIG. 5 illustrates a white wine glass 70 , and FIG. 6 illustrates a champagne glass 80 . FIG. 7 illustrates a Stein glass 90 , and FIG. 8 illustrates another wine glass 100 . FIG. 9 illustrates a margarita glass 110 , and FIG. 10 illustrates another martini glass 120 . FIG. 11 illustrates a tumbler 130 that is similar to mug 50 of FIG. 4 without a handle. Other types of glasses include red wine glasses, brandy snifter glasses, along with essentially any other type of glass or beverage container.
FIG. 12 illustrates one embodiment of a tray 140 having a plurality of recessed regions 141 that may be semi-cylindrical in geometry for holding a set of cylindrical cooling elements 142 . In this way, multiple cooling elements 142 may simultaneously be placed into a freezer while using minimal space. When a beverage container needs a new cooling element, it may simply be removed from tray 140 and placed into the cavity as previously described. The old cooling element may then be placed onto tray 140 which is placed into the freezer. Further, it will be appreciated that tray 140 may have any shape of indentation needed to match the shape of the cooling element, including any of the shapes described herein.
FIG. 13 illustrates an alternative tray 150 having a plurality of hemispherical recesses 152 for receiving hemispherical cooling elements. Tray 150 may be used in a manner similar to tray 140 .
The invention has now been described in detail for purposes of clarity and understanding. However, it will be appreciated that certain changes and modifications may be practiced within the scope of the appended claims. | In one embodiment, a beverage container comprises a vessel having an interior that is adapted to hold a beverage. The vessel has a closed bottom end and an open top end. The bottom defines a cavity that is fluidly filled from the interior of the vessel. A cooling element is configured to fit within the cavity. A base comprises a bottom member and a stem extending vertically upward from the bottom member. The base includes a connector that is configured to be coupled to the bottom end of the vessel and to enclose the cooling element within the cavity. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/011,847 filed on Feb. 16, 1996.
BACKGROUND
1. Technical Field
The present disclosure relates to magnetic fasteners, and more particularly to a magnetic fastener which is configured to contain the magnetic field and reduce leakage thereof.
2. Background of the Related Art
There have been many attempts to develop a commercially successful magnetic fastener for use in various applications such as for handbag closures. Included among these attempts are U.S. Pat. Nos. 2,812,203, 2,884,508, 3,372,443, 3,618,174, 3,919,743, 4,455,719, 4,458,396, 4,231,137, 4,754,532, 4,825,526, 4,021,891, 4,700,436, 4,453,294, 5,042,116, 5,142,746, 5,274,889, 5,251,362, 5,400,479 and 5,379,495.
For convenience of explanation of prior art fasteners, such fasteners are illustrated generally in FIG. 1 to which reference is being made. One disadvantage of presently known fasteners is that they fail to effectively contain the leakage of lines of magnetic flux both when the fastener is open as well as after the fastener is in the closed position. For example, referring to FIG. 1, for a magnetic fastener 10 manufactured as described in certain of the above listed patents, substantial magnetic flux leakage 12 radiates in all directions from magnet 14 with the primary leakage being laterally or radially around the perimeter of the magnetic fastener 10. This radial leakage occurs because there is no provision to contain magnetic flux lines 12 in a closed path around the periphery of fastener 10 and thus the lines of flux 12 extend out and around to the back of both the male plates 16 and female plates 18. Such leakage may cause damage to devices such as credit cards, computer disks and other items which store information or magnetic media.
Second, the above referenced fasteners depend primarily upon magnetic attraction to keep their parts in the closed position while using other means to prevent lateral movement and thus disengagement. The problem of lateral movement in all of the above fasteners is in part solved by the placement of pin 20 or other protrusion on at least one of the parts which fits into a receiving hole 22 defined in the other part 18 (FIG. 1). However, this configuration is not sufficiently effective when a lateral force is applied to the two parts of the fasteners, and the pin is moved off center relative to the corresponding pin on the second part of the fastener. This misalignment weakens the magnetic connection between the two parts. U.S. Pat. No. 5,042,116 to Ossianni attempts to stop this movement with a counter-sinking pin which fits snugly into a recess in the opposing pin. This arrangement requires difficult and costly manufacturing of the pins. Even the smallest amount of dust or magnetically attractive sand in the receiving recess will prevent the pin from seating properly, which weakens the magnetic circuit and thus the holding power of the fastener.
Magnetic fasteners, such as those described in the above patents, are primarily used on items such as handbags, which presents additional design problems. For example, at least one part of the fastener is affixed to a somewhat flexible member, such as the flap of the bag. This further decreases the holding strength of the fastener when a lateral separating force is applied to such fastener. Upon such application of lateral force to the fastener as described, the fastener rotates on its own axis until the attractive force of the magnet is no longer perpendicular to the long axis of the pin, which is oriented at a right angle to the face of the magnet. Because the magnetic attracting force is centered through the pin and at a right angle to the face of the magnet, when this rotation occurs, less force is required to disengage the two parts.
Further, when lateral force is applied to the currently available commercially successful magnetic fasteners, the pin may slide to the side of the hole and ride up and over the rim of the hole. This movement changes the direction of resistance from a line perpendicular to the face of the magnet (the angle of the greatest resistance to separation) to an are or angle of less than 90° to the face of the magnet (a direction of lessened resistance to separation).
The present invention relates to a magnetic fastener which avoids the above described problems by encapsulating the lines of magnetic flux which radiate from the magnet. The fastener also incorporates further mechanical attachment to augment the magnetic attraction of the magnetic fastener.
SUMMARY
The present invention is directed to a unique magnetic fastener having a magnetically attractive first element and a magnetically attractable second element. First element includes a cylindrical shaped magnet defining an axial bore and having first and second axial ends with first and second opposite polarities, respectively. An annular cover member is provided which covers the first axial end of the cylindrical magnet. First element further includes a ferromagnetic plate having a portion adjacent the second axial end of the cylindrical magnet and a generally cylindrical wall portion disposed around the cylindrical shaped magnet and radially spaced a predetermined lateral distance therefrom. The cylindrical wall is preferably monolithically formed with the ferromagnetic plate. The cylindrical wall is connected to the annular cover member, and may have a thickness substantially greater than the thickness of the annular cover member. A ferromagnetic rod extends from the ferromagnetic plate into the axial bore of the cylindrical magnet. The second element is positionable adjacent the annular cover member.
Annular cover member includes an aperture fixedly aligned with the axial bore and of a lesser dimension than the axial bore so as to define a rim portion extending into the area defined by the axial bore. The second element includes a protrusion having a peripheral recess therein which defines a peripheral undercut thereon adjacent the rim portion. The protrusion is positionable within the axial bore movable laterally therein such that the rim portion is engaged with the undercut to provide mechanical interference to prevent accidental separation of the first and second elements by simultaneous lateral and axial movement of one from the other.
These and other features of the magnetic fastener will become more readily apparent to those skilled in the art from the following detailed description of preferred embodiments of the subject disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
Various embodiments of the surgical magnetic fastener are described herein with reference to the drawings wherein:
FIG. 1 is a cross-sectional view of a representative one-half portion of a magnetic fastener constructed in accordance with the prior art;
FIG. 2 is a perspective view in reduced scale, of the magnetic fastener constructed in accordance with a preferred embodiment of the subject disclosure, illustrating attachment to a handbag;
FIG. 3 is a perspective view with parts separated of the magnetic fastener of FIG. 2;
FIG. 4 is a cross-sectional view of the magnetic fastener, illustrating the approximation of the two elements;
FIG. 5 is an enlarged cross-sectional view of a representative one-half portion of the magnetic fastener of FIG. 2, illustrating the encapsulation of magnetic flux lines;
FIG. 6 is an enlarged cross-sectional view of a representative one-half potion of the magnetic fastener, constructed in accordance with a second preferred embodiment of the subject apparatus;
FIG. 7 is a cross-sectional view of a representative portion of the magnetic fastener, constructed in accordance with a third preferred embodiment of the subject apparatus;
FIG. 8 is a cross-sectional view of a representative portion of the magnetic fastener, constructed in accordance with a fourth preferred embodiment of the subject apparatus; and
FIG. 9 is a cross-sectional view of the magnetic fastener, constructed in accordance with a fifth preferred embodiment of the subject apparatus.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring now in detail to the drawings in which the reference numerals identify similar or identical elements, a preferred embodiment of the subject invention is illustrated in FIG. 2, and is designated generally by reference numeral 100. Magnetic fastener 100 is typically attached to an item, such as handbag H. Magnetic fastener 100 will have many other applications such as, for use as a closure for jewelry, belts, garments and other items.
As illustrated in FIG. 3, magnetic fastener 100 consists of at least eight major components and makes effective use of more of the available magnetic attraction of the magnet used than any of the fasteners described above. In particular, the present fastener effectively uses and/or controls and encapsulates virtually 100% of the available magnetic flux by generally forcing it into a path which is as close as possible to the surface of the magnet without shorting out the magnetic circuit. Referring again to FIG. 3, magnetic fastener 100 includes magnetically attracting female portion 102, which is preferably attached to one part, e.g. the body, of handbag H, and magnetically attractable male portion 104, which is attached to a second part, e.g. the flap, of handbag H. Female portion 102 includes female base plate 106, which has an annular ring or outer perimeter or cylindrical wall 108, with a toothed, textured or grooved inner surface 110 (See, FIG. 3). Female base plate 106 defines hole 112 extending therethrough. Female prong plate 114 defines hole 116 and has a plurality of attachment protrusions 118a and 118b for securing female portion 102 to handbag H. Protrusion or rivet 120 extends through hole 112 in base plate 106 and hole 116 in prong plate 114.
Generally cylindrical magnet 124 has at least one axial bore 126 extending from first axial end 132 to second axial end 134. Magnet 124 defines outer peripheral wall 128 and an inner wall 130. Magnet cover member 136 includes a top surface 142 defining a hole 138 extending therethrough, with an edge or rim 140, an angled end wall 144 and a side wall 146. Side wall 146 has a textured, toothed or grooved outer surface 154.
With reference to FIG. 4, cylindrical wall 108 extends in an upward direction from base plate 106 and is monolithically fabricated therefrom as a single component. Cylindrical wall 108 is formed at essentially a right angle to plate 106 and is of sufficient height as to bring its upper edge adjacent, but not into contact with male base plate 150. Cylindrical wall 108 is preferably two millimeters in height. Cylindrical wall 108 may have an uneven, notched, or textured upper edge. Hole 112 in base plate 106 receives protrusion or rivet 120, which is used to hold prong plate 114 and base plate 106 together.
Cylindrical wall 108 has a textured, toothed and/or grooved inner surface 110, which surface cooperates with a mating surface 154 located on the outer surface of magnet cover 136 (FIG. 4). By "textured surface" is meant that one surface is roughened either randomly or by formation of parallel step-like grooves, which mate with an opposed surface which is correspondingly roughened or grooved in a similar fashion. One such example of a grooved "textured" surface will be described below in connection with FIG. 6. Through such texturing, surfaces 110 and 154 thereby cooperate by interference fit and/or friction-like action to hold cover 136, base plate 106 and magnet 124 together upon assembly, as well as in place in their proper spaced relationship relative to one another.
Female prong plate 114 defines hole 116 extending therethrough for receiving protrusion or rivet 120. Prong plate 114 has at least two prongs 118a and 118b or other protrusions extending therefrom for use in attaching female portion 102 of the fastener 10 to an item such as handbag H.
Protrusion or rivet 120 is fabricated from a ferromagnetic material and has a top surface 156 which comes into contact with a matching end surface 158 located on protusion or rivet 160 disposed on male portion 104 when the male portion 104 and female portion 102 of magnetic fastener 10 are brought together into the closed position. Male portion 104 is illustrated in FIG. 4 in phantom lines in a spaced apart position with respect to female portion 102.
Referring again to FIG. 1, magnet 124 provides the magnetic attractive force for fastener 100. Magnet 124 has axial bore 126 which is larger in diameter than protrusion or rivet 120. Axial bore 126 in magnet 124 has an inner wall 130, an outer wall 128 and two opposing axial ends 132 and 134. First axial end 132 and second axial end 134 have opposite magnetic polarity.
Cover plate 136 is preferably made of a non-magnetic material, such as brass or molded plastic, and is fabricated with a generally annular configuration. Hole 138 in cover plate 136 receives said protrusion or rivet 160. Hole 138 is of lesser dimension than axial bore 126 of magnet 124 so as to define lip or rim 140 around the periphery of hole 138. Rim 140 is of sufficient thickness as to cooperate with peripheral notch or undercut 164 located on rivet 160 of male portion 104, as will be described below. When male portion 104 and female portion 102 are in the closed position such that rivet 160 is disposed in axial bore 126, lip or rim 162 is engaged wit notch or undercut 164 to provide a mechanical safety connection between male portion 104 and female portion 102 of fastener 100 when a simultaneous lateral and axial separating force is applied to fastener 100.
Referring again to FIG. 4, angled end wall 144 of cover plate 136 is located at the junction between top plate 142 and side wall 146. Preferably, angled end wall 144 may form an angle of between 3 degrees and 90 degrees with top surface 142 and with first axial end 132 of magnet 124. Angled end wall 144 maintains magnet 124 in proper spaced relationship relative to both the outer wall 128 of magnet 124 and cylindrical wall 108 of base plate 106, as well as maintaining the said magnet 124 in a proper spaced relationship between inner wall 130 of magnet 124 and protrusion or rivet 120.
Side wall 146 of cover plate 136 has a textured, toothed or grooved outer surface 154, which surface cooperates with a mating surface 110 located on the interior of cylindrical wall 108 of base plate 106. The aforementioned cooperation between said mating surfaces 154 and 110 holds cover 136 in place after the assembly of female part 102 fastener 100. Cover plate 136 may be held in place by friction or by an adhesive. Additionally, cover plate 136 may have a sprayed-on or dipped-on color coating or metallic coating.
Male portion 104 consists of at least three components (FIG. 3). Male base plate 150, which defines a through hole 172 for receiving protrusion or rivet 120 and face, or exposed, surface 174. Male prong plate 176, which defines a through hole 178, a front surface 180, a back surface 182 and a plurality of protrusions 184a and 184b, which are used in attaching male portion 104 of fastener 100 to an item such as handbag H. Protusion or rivet 160 has contact surface 158 and a notch or undercut 164.
Male base plate 150 has a through hole 172, which is aligned with hole 178 in prong plate 176. As illustrated in FIG. 4, male base plate 150 and prong plate 176 are held together by rivet 160. Rivet 160 has a notch or undercut portion 164, which works in conjunction with lip 140 to form a mechanical connection between male portion 104 and female portion 102 of fastener 100 when a lateral force is applied to fastener 100. The mechanical connection also resists the off-center arcing or angular displacement described above. This connection is a safety mechanism and is not the primary means by which fastener 100 is held together.
Contact surface 158 of rivet 160 protrudes away from the face surface 174 of base plate 150 to a sufficient distance so as to insure that when rivets 160 and 120 come into contact, there is maintained at least a minimum gap of 0.005 millimeters between the top surface 142 of magnet cover 136 and the face or exposed surface 174 of base plate 150 to prevent the surface of either male base plate 150 or female base plate 106 from becoming scratched when lateral, side to side movement occurs between the male portion 104 and female portion 102 of fastener 100.
With reference to FIG. 5, cylindrical wall 108, which is formed monolithically with female base plate 106, extends upward from female base plate 106 toward the edge of male base plate 150. A path is created which effectively contains magnetic flux 180. Cylindrical wall 108 and base plate 106 are a fabricated of a ferromagnetic material. By maintaining cylindrical wall 108 at a predetermined radial distance from outside wall 128 of magnet 124, the lines of magnetic flux 180 which radiate out from the side of magnetic fastener 100 are encapsulated, both when fastener 100 is in the closed as well as the open position.
Tuning now to FIG. 6, a second preferred embodiment of the magnetic fastener is shown and designated by reference numeral 200. Magnetic fastener 200 is constructed substantially as described above with reference to magnetic fastener 100, with the differences noted below. In particular, cover plate 236 of magnetic fastener 200 is a male member which includes side wall 246, which defines an outer surface 248. Outer surface 248 cooperate with a mating inner surface 210 located on the interior of cylindrical wall 208 of base plate 206. Thus it can be seen that base plate 206 acts as a female member with male member 236. As can be seen in FIG. 6, outer surface 248 of side wall 246 has a textured surface which is greatly enlarged in FIG. 6 and is defined by a plurality of parallel thread-like grooves 249 extending about outer surface 248 which cooperate with complementary thread-like grooves 211 formed on surface 210 of cylindrical wall 208.
FIG. 7 illustrates a third preferred embodiment of the magnetic fastener designated by reference numeral 300. Magnetic fastener 300 is constructed substantially as described above with reference to magnetic fastener 100, with the differences noted below. In particular, cover plate 336 of magnetic fastener 300 includes side wall 346, defining an inner surface 348 which cooperates with a mating outer surface 310 located on the exterior of cylindrical wall 308 of base plate 306. Preferably, cylindrical wall 308 includes a groove 311 which receives an inwardly extending ridge 349 formed on inner surface 348 of side wall 346. It is contemplated that groove 311 and ridge 349 may be interchanged between cylindrical wall 308 and side wall 346, and that other connecting means may be used.
FIG. 8 illustrates a fourth preferred embodiment of the magnetic fastener designated by reference numeral 400. Magnetic fastener 400 is constructed substantially as described above with reference to magnetic fastener 100, with the differences noted below. Cover plate 436 defines side wall 446 which is spaced a predetermined distance from magnet 124. Encapsulation of magnetic flux is accomplished by cylindrical wall 408, which may be a ferromagnetic coating applied or formed on side wall 446.
FIG. 9 illustrates a fifth preferred embodiment of the magnetic fastener designated by reference numeral 500. Magnetic fastener 500 is constructed substantially as described with reference to magnetic fastener 100, with the differences noted below. In particular, cover plate 536 includes angled portion 544 which extends from magnet 124 to cylindrical wall 508, spaced a predetermined distance from magnet 124. Cover plate 536 further includes inner side wall 560 adjacent interior of cylindrical wall 508, upper wall 562 adjacent upper portion of cylindrical wall 508, and outer side wall 564 adjacent exterior of cylindrical wall 508.
The above-described configurations have the following advantages. It provides a balanced mass with an exterior insulating annular wall which effectively guides and encapsulates the magnetic flux radiating from the magnet used. Said flux thus being maintained within the closest possible proximity to the magnet 124 without shorting out the magnetic circuit. This configuration provides far better protection against accidental damage to items such as credit cards and computer disks, caused by the leakage of magnetic flux from the snap, than is afforded by magnetic snaps manufactured according to any of the above mentioned patents.
It provides for the fuller usage of the available magnetic attraction potential of the magnet. This is accomplished by forcing the magnetic flux or forces lines, which in other designs would normally escape and dissipate uselessly form the sides of the snap, into a tight path up the side of the magnet and into the male plate 150.
It provides for superior protection against the unintentional disengagement of the snap parts when lateral force is applied to the closed snap by use of a mechanical safety connection. It is cost-effective to manufacture as the additional safety feature, as well as the exterior magnetic buffer, are achieved without the use of any additional parts. It can be more easily sealed against water and other contaminants because of the tight tolerances involved between the outer wall of magnet cover 136 and the inner surface of cylindrical wall 108.
The arrangement lends itself to automated mass manufacture and assembly and thus savings. This is because the fabrication sequence has fewer steps than that of the current commercially successful magnetic snaps.
It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications as preferred embodiments. | A magnetic closure device is disclosed, having a magnetically attractive first element including a cylindrical shaped magnet defining an axial bore and having first and second axial ends with first and second opposite polarities respectively, and an annular cover member covering the first axial end of the cylindrical magnet. First element further includes a ferromagnetic plate having a portion adjacent the second axial end of the cylindrical magnet and a generally cylindrical wall portion disposed around the cylindrical shaped magnet and radially spaced a predetermined lateral distance therefrom. The cylindrical wall is connected to the annular cover member. A ferromagnetic rod extends from the ferromagnetic plate into the axial bore of the cylindrical magnet. A magnetically attractable second element is disclosed which is positionable adjacent the annular cover member. | 8 |
FIELD OF THE INVENTION
This invention is generally related to punch tools, and particularly to a children's punch tool having an interchangeable die and punch so different shapes or configurations can be punched through sheets of paper.
BACKGROUND OF THE INVENTION
A variety of punch tools are available for punching holes through sheets of material, such as paper. For example, conventional triple punches are used to simultaneously punch three circular holes through sheets of paper so the paper can be clipped into a three ring binder. Those punches are generally large, difficult for a child to carry, and limited in their uses.
Other punch tools are smaller and use a single punch. They typically have a base portion to which a top portion is pivotally attached. The base portion either includes a die area or has a separate die attached thereto. A punch cooperates with the pivotable top and is forced through the die to punch holes through sheets placed over the die. Generally, a spring biases the punch and the pivotable top away from the die and base portion.
These punch tools are problematic for a variety of reasons, including the number and complexity of components. Additionally, most of the punch tools do not provide for interchangeable dies and punches, and those that do are generally constructed in a complex fashion making it difficult for a child to interchange the die and punch. Further, most existing punch tools have a pivotable top portion that pivots towards the base and can be awkward to handle, particularly for a child.
It would be advantageous to have a simple, easy to use punch tool including interchangeable dies and punches.
SUMMARY OF THE INVENTION
The present invention relates generally to a safe, easy to use punch tool particularly for children. The punch tool can be used to punch a variety of holes through sheets, such as paper sheets, and includes a base portion on which the sheets are placed when punched. The punch tool also includes a die and a cutter element disposed to cooperate with the die.
The punch tool also includes a cap securely attached to the base and having an aperture therethrough. A push button or actuator button is configured for movement through the aperture, and the bottom of the push button is shaped for contact with the cutter element to force the cutter element towards the die. A spring is mounted intermediate the base and a portion of the cutter element to bias the cutter element and the push button away from the base. Preferably, the spring acts against the die and the cutter element.
Holes may be punched by placing a sheet on the base and sliding it inwardly until it is beneath the cutter element. Then, application of sufficient pressure against the push button overcomes the spring bias and moves the cutter element into cooperation with the die to punch a hole of predetermined configuration through the sheet.
According to another aspect of the invention, the die and the base each include an attachment region, so the die may be quickly inserted into and removed from the base. The cutter element may be removed with the die. Thus, different die and punch combinations can easily be used with the punch tool to provide punched holes having a variety of configurations.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
FIG. 1 is a front elevational view of a punch tool according to a preferred embodiment of the invention;
FIG. 2 is a back elevational view of the punch tool shown in FIG. 1;
FIG. 3 is a side elevational view of the punch tool shown in FIG. 1;
FIG. 4 is a top plan view of the punch tool shown in FIG. 1;
FIG. 5 is a bottom view of the punch tool shown in FIG. 1;
FIG. 6 is a cross-sectional view taken generally along line 6--6 of FIG. 4;
FIG. 7 is an exploded perspective view of the punch tool components;
FIG. 8 illustrates a first example of a potential configuration for the die and punch;
FIG. 9 illustrates a second example of a potential configuration for the die and punch; and
FIG. 10 illustrates a third example of a potential configuration for the die and punch.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring generally to FIGS. 1-5, a punch tool 12 according to a preferred embodiment of the invention is illustrated. Punch tool 12 includes a base 14 to which a die portion 16 is attached. A cutter element, such as punch 18, is disposed to cooperate with die portion 16 to punch holes through sheets. A cap 20 is attached to base 14, preferably by a fastener, such as a plurality of threaded screws 22.
Cap 20 includes an aperture 24 therethrough that is sized to receive an actuator button 26. Actuator button 26 is appropriately sized for sliding, reciprocating motion within aperture 24. A resilient member, such as spring 28, biases actuator button 26 and punch 18 away from base 14. (See FIG. 6)
Each of the components will now be described in greater detail referring also to FIGS. 6 and 7. Base 14 includes a top wall 30 having a generally flat top surface 32 on which sheets may be laid during the punching operation. A sidewall 34 extends generally downwardly from top wall 30 and forms a hollow bottom region 36. Optionally, a plurality of crossed ribs 38 may be disposed to protrude downwardly from top wall 30.
A plurality of apertures 40 extend through base 14 and are configured to receive screws 22 therethrough. Additionally, base 14 includes an opening 42 and an attachment regions 44 disposed generally along the perimeter of opening 42 to releasably receive die portion 16.
Opening 42 is designed to completely receive die portion 16 when it is inserted upwardly from the bottom of base 14 at an orientation approximately 90° from its working orientation, although the orientation can be changed depending on the configuration of attachment regions 44. In the preferred embodiment, attachment region 44 allows die portion 16 to be rotated approximately 90° after insertion and then holds the die portion in this operating position where it can receive sheets of material.
Attachment regions 44 comprise a plurality of tabs including front lower tabs 46, front upper tab 48, and back tab 50 which cooperate to hold die portion 16 in place once inserted and rotated into base 14. Attachment regions 44 also may include an extension 52 configured to snap into mating engagement with die portion 16 to prevent unwanted rotation thereof. It should be noted that the number and arrangement of the tabs can be changed, and the illustrated embodiment is only one example of many which would adequately hold die portion 16.
Die portion 16 includes a main body 54 having a slot 56 sized to receive the sheets therein. A lower surface 58, defining one side of slot 56, is disposed for general alignment with flat top surface 32 of base 14 when die portion 16 is inserted into base 14. Thus, a sheet of paper may be slid along flat top surface 32 and into slot 56 along lower surface 58 prior to punching. Main body 54 also includes a shearing edge 60 (see FIG. 6) having a predetermined configuration or shape corresponding to the shape to be punched through the sheet of paper. An attachment region 62, including outer lips 64, extends outwardly from main body 54 and is configured to cooperate with attachment region 44. In other words, when die portion 16 is inserted into base 14 and rotated, outer lips 64 rest on back tab 50 and between front lower tab 46 and front upper tab 48 where die portion 16 is held in place by the extension 52 interacting with outer lips 64. Outer lips 64 may have a slightly recessed area designed to snap over extension 52 to aid in preventing accidental rotation of die portion 16 prior to intended exertion of sufficient rotational force. A gripping member 66 extends downwardly from main body 54 and provides an area for a user to grip and rotate die portion 16.
A guide 68 extends upwardly from main body 54 above slot 56 and includes a guide aperture 70 through which punch 18 moves. Aperture 70 helps guide punch 18 across slot 56 and past shearing edge 60 to punch an appropriate hole through a sheet disposed in slot 56 (See FIG. 6). Guide 68 may also be configured to hold spring 28 in place. For instance, if spring 28 is a coil spring, guide 68 may be appropriately sized for insertion into the center of the spring to prevent the spring from sliding laterally with respect to die portion 16 as shown in FIG. 6.
Die portion 16 may also include a pin 72 that extends upwardly from main body 54 and is preferably fitted through an orifice in a tab 73 attached to punch 18. Alignment pin 72 effectively holds die 16, spring 28 and punch 18 together.
Punch 18 is located generally between base 14 and retainer cap 20 and is designed for cutting in cooperation with shearing edge 60 of die portion 16. In the preferred embodiment, punch 18 includes a center portion 74, such as a radially extended platform preferably having a disk-like configuration. Center region 74 has a first side 76 and a second side 78 generally opposite first side 76. A cutting edge or shearing edge 80 extends from first side 76 toward shearing edge 60 of die portion 16. An indicator 82 extends from second side 78 and indicates the shape or configuration of shearing edge 80.
Preferably, spring 28 is a coil spring trapped between center region 74 of punch 18 and base 14. As illustrated, the spring may be disposed to act against first side 76 of center region 74 at one end and main body 54 of die 16 at the other end to generally bias punch 18 away from base 14.
Retainer cap 20 includes an attachment region 84 disposed generally along its back side. Attachment region 84 includes a plurality of openings 86 into which fasteners 22 may be threaded to securely and rigidly attach retainer cap 20 to base 14 along the back portion of base 14. Retainer cap 20 also includes a raised or indented region 88 that permits sheets of paper to be slid between cap 20 and top surface 32 of base 14 and then moved into slot 56 of die portion 16.
Retainer cap 20 further includes aperture 24 for slideably receiving actuator button 26. An upper ridge 92 is disposed at least partially about the perimeter of aperture 24 towards the top of cap 20. Also, a plurality of tabs 94 extend downwardly into the interior of cap 20 and have hooked ends 96 that extend radially inwardly in the interior of cap 20. Ridge 92 and hook ends 96 cooperate to hold actuator button 26 in retainer cap 20 while permitting reciprocable motion of actuator button 26 between ridge 92 and hooked ends 96. Actuator button 26, in turn, includes an outer ridge 98 that may be snapped over hooked ends 96. Button 26 is thus prevented by outer ridge 98 from disconnecting with retainer cap 20 until a user supplies sufficient pressure against actuator button 26 to force ridge 98 past the hooked ends.
Additionally, actuator button 26 includes an aperture 100 appropriately sized so indicator 82 of punch 18 can be viewed by a user (see FIGS. 4 and 6). Aperture 100 is also sized to permit second side 78 of punch 18 to abut a bottom surface 102 of actuator button 26. Thus, when die portion 16, punch 18, and spring 28 are assembled into punch tool 12, spring 28 biases punch 18 against bottom surface 102 of actuator button 26. This permits punch tool 12 to be operated simply by placing sufficient pressure against the top of actuator button 26 to overcome the biasing force of spring 28. Then, edge 80 of punch 18 is moved into cooperation with shearing edge 60 of die portion 16.
In the illustrated embodiment, actuator button 26 is generally cylindrical in shape and retainer cap 20 is generally hemispherical in shape. However, these components can be can be made in a variety of other shapes and configurations.
Referring also to FIGS. 8-10, a variety of exemplary die and punch configurations are illustrated. The shearing edges of punch 18 and die portion 16 may be made in any of a variety of shapes and configurations, including the triangle of FIG. 8, the square of FIG. 9, and the sailboat of FIG. 10. The design of punch tool 12 allows an individual, such as a child, to quickly and easily insert different die portions and punches and then operate punch tool 12 to create apertures of different shapes easily and efficiently. Die portion 16, punch 18, and spring 28 can be attached to one another to permit changing of the die and punch as a single assembly rather than as individual components.
In operation, the user simply selects a desired shape to be punched and then inserts the appropriate punch 18 into the corresponding die portion 16 with spring 28 disposed therebetween. Or, if die portion 16, punch 18, and spring 28 are connected together as assembly 73, the user simply selects the assembly having the desired shape to be punched. The assembly or the individual components are aligned with base 14, moved upwardly into base 14 and rotated until the attachment region 62 of die portion 16 cooperates with attachment regions 44 of base 14 to hold die portion 16 in its operational position. Thereafter, a sheet of paper is slid over top surface 32 of base 14 and into slot 56 of die portion 16. The user then checks indicator 82 through actuator button 26 to insure the proper cutting configuration. If correct, the user presses downwardly on actuator button 26 to overcome the biasing force of spring 28 and punches a hole of desired configuration through the sheet.
If a hole of a different configuration is desired, the user simply rotates die portion 16 with the assistance of gripping member 66 until die portion 16, spring 28, and punch 18 fall downwardly through opening 42 of base 14. After removal, a second die and punch assembly is inserted into base 14 so holes of this second configuration can be punched.
A variety of materials may be used for the various punch tool components. However, it is preferred that die portion 16 and punch 18 are made of cast zinc, while base 14, cap 20, and button 26 are made of plastic such as polycarbonate.
It will be understood that the foregoing description is of preferred exemplary embodiments of this invention and that the invention is not limited to the specific forms shown. For example, the various punch tool components can be made from a variety of materials. Additionally, the retainer cap can be attached to the base by other fasteners such as adhesive or even by integrally molding the cap with the base. The resilient member can also be made from a variety of materials and in a variety of configurations. Other modifications may be made in the design and arrangement of the elements without departing from the scope of the invention as expressed in the appended claims. | A punch tool for use by children is disclosed. The punch tool includes a removable die and punch assembly that can be inserted and removed from a base portion to permit the punching of holes having a variety of configurations. A cap is rigidly secured to the base and has an indented portion so sheets of paper can be inserted between the base and the cap. The retainer cap includes an opening in which an actuator button is slidably mounted and against which the punch is biased by a spring. Thus, a user can slide a sheet of paper between the base and the retainer cap and punch a hole therethrough by pressing the actuator button with sufficient force to overcome the spring bias. | 8 |
FIELD OF THE INVENTION
This invention relates to electrical connecting devices, more particularly to connectors used to connect cables to connector ports or terminals on electrical distribution equipment and especially to connectors used in taps for connecting coaxial cables in the cable television industry.
BACKGROUND OF THE INVENTION
The conventional coaxial cable usually consists of an electrically conducting center conductor, a first layer comprising a dielectric, a second layer comprising an electrically conducting sheath, a third layer comprising a braid, and a fourth layer comprising a jacket, or multiple layer combinations of either or both.
Currently, cable TV network systems use outdoor and indoor taps which are constructed as in FIG. 1. At least one input 11 and in most cases one output 12 are connected with the cable wire to transmit the signal to the next device. Networks on the inside of the taps including the printed circuit board (pcb) of tap units distribute and transmit the signal through F-port connector 13, then through cable wire to the end user. One such tap is disclosed and claimed in U.S. Pat. No. 4,887,979, commonly assigned herewith.
The conventional F-port connector 13 is generally tubular in configuration and may have a front end carrying an appropriate fastener designed to mate with equipment ports or terminals. Additionally, the conventional F-type connector or port comprises a standard female interface and includes a first hollow annular member having a generally cylindrical inner surface, end openings and a generally cylindrical outer surface extending for a portion of the axial length of the first annular hollow member.
Such connectors are used in the television industry, for example, on equipment for distributing signals to customers homes. Any signal not being used must be terminated without leakage. Normally, this is done with a separate external terminator connector.
Additionally, in the cable television industry, it is common to have many subscribers connected to the system via multiple connections. Electrical connecting devices are commonly used throughout the industry and it is not uncommon for any number of customers to be connected for differing and varying services delivered via a cable wire or wires. Problems arise when one or more customers opt for multiple service options such as cable television and/or telephone service through the same distribution system or when one or several customers wish to terminate service. These problems may be illustrated by considering, for example, the actions necessary in a neighborhood where via a tap housing as illustrated in FIG. 1, multiple customers are connected to the cable television system, when one customer wants to add telephone service through the cable system or another wishes to disconnect the system altogether, and/or another wishes to add the telephony and terminate the television service. With present technology, to accommodate these customers a field technician must go to the site to open the tap distribution unit and put an additional connection wire to add the telephony. It also requires a field technician to screw the unit apart and disconnect or remove the wire to discontinue telephony services; and to install a terminator connector for discontinued RF (TV) signals to the disconnected unit. If a terminator is not installed on all unused F-ports or connectors, the quality of the signal will be degraded and additional problems along with customer complaints will be generated. Additionally, in many cases the terminator is dropped or lost by the field technician and as a consequence is not installed and the unit is then left unterminated and the quality of the signal is degraded for the remaining customers.
Automatically terminating printed circuit board BNC connectors are known. Such pcbs are useful in input-output ports for network adapter cards, video matrix switches, video amplifiers, test equipment such as local oscillator and calibration outputs of signal analyzers, etc. one such known connector comprises a printed circuit board mounted BNC connector, terminating resistor, and moveable center conductor, and is advertised as containing a chip resistor which bridges the signal and ground paths when the connector is not mated to a BNC plug. This connector breaks the termination state by utilization of the center conductor of the mating. When the two connectors are attached to each other, the center pin from the mating part moves the center contact pin of the self-terminating connector opening the terminating circuitry. This arrangement is effective with BNC connectors because the center conductor of the mating part is a rigid pin. This arrangement is not effective with an "F" type connector because in "F" connectors, the center contact is the center conductor of the cable and it will bend or deflect or break during the contact necessary to move the pin to actuate the termination. There is thus a continued need in the art for self-terminating "F"-type connectors.
SUMMARY OF THE INVENTION
An object of this invention is to provide an electrical connector for distribution equipment that is easily switchable, for example (but not limited to) between RF (5 MHZ to 1 Ghz) and RF with power.
Another object of this invention is to provide an electrical connector for distribution equipment that automatically terminates unused signals in the equipment.
Another object of the invention is to provide such an automatic termination electrical connector and/or a switchable connector and/or combination thereof that is free of the disadvantages of the prior art indicated above and therefore provides an electrical connecting device that is substantially improved over known electrical connecting devices.
For ease of discussion and illustration, the invention will be described in terms of its application as an electrical connecting device containing a connector that is commonly referred to as an F-port connector. However, it will understood that the connecting device need not and should not be limited to use as an F-port connector and is suitable for connecting wires of different types of devices together where the ability to automatically terminate unused signals or current flow or to switch between various circuits to deliver various types of services is important.
The invention provides a means to automatically terminate the input of an electrical connecting device when a cable and mating connector is not installed without opening the tap or connector unit to provide access to the inside to make a change. This will allow a tap that is installed in a CATV system to supply power to customers requiring it and to automatically terminate the signal once the service is disconnected or discontinued without having to install a separate terminator on the unused F-ports. When a customer wishes to discontinue the service, the service provider needs only to actuate a pre-installed actuating mechanism present in the installed F-port connector.
The invention also provides a means to switch between two outputs, for example, between RF and RF with power from outside the unit, without opening the unit and without the need for extra internal parts, connectors, or devices, and without opening the tap or connector unit to provide access to the inside to make a change. This will allow a tap that is installed in a CATV system to supply RF with power to only customers requiring it for telephone service, for example, and to supply only RF for customers that subscribe to only cable television service. When a customer wishes to add telephone service, the installer only has to rotate the previously installed connector to turn on the power that will be required to operate the telephone to activate the additional service.
The invention provides means to switch between services and to automatically terminate the input of the electrical connector when a cable and mating connector is not installed without opening the tap or connector unit to provide access to the inside to make a change or to terminate the unused signals.
THE SWITCHABLE CONNECTOR
According to the invention, a construction is provided wherein a plunger or actuator pin in the connector and a capacitor cooperate so that when the connector is operating in one mode, the plunger or pin contacts the capacitor, the circuit is opened, and the signal flows. To switch the connector to a different mode, the connector is rotated, the capacitor blocks the first mode and operation in the second mode is established. The device comprises a tap housing which includes an F-port connector and the switching mechanism. The tap housing containing the F-port is installed in a CATV system to selectively supply RF with power to customers who subscribe to telephone service; and to provide only RF to customers who subscribe only to cable service such as cable television programs. It permits the service provider to install a single connector whenever it installs cable television services and to subsequently add telephone service from outside the location of the services by rotation of the connector to connect and turn on the power required to operate the telephone to provide telephone services.
In general, in accordance with the invention, there is provided, in its broadest sense, an electrical connector for making electrical connections between first electrical signal providing means and first electrical signal receiving means and alternatively between second electrical signal and power providing means and second electrical signal and power receiving means, and combinations thereof, said connector containing an inner resilient conductor member connectable to an electrical circuit when contacting circuit-providing means contained in the housing, such as a printed circuit board (pcb), switching means operatively associated with the inner resilient conductor member and the circuit-providing means for selectively opening or closing an electrical connection between either the said first means or the said second means and the said combinations thereof when the inner resilient conductor member contacts the circuit-providing means.
In preferred embodiments of the invention, the electrical connecting device is for use as an F-port in a cable television ("CATV") system which includes making electrical connections between first electrical signal providing means and first electrical signal receiving means to provide services including the provision of video and specifically, television, and alternatively between second electrical signal and power providing means and second electrical signal and power receiving means to provide services including telephone services, and combinations thereof, said connector containing the switching means comprising an inner resilient conductor member as described above for selectively making or breaking the electrical connection between the said first means and a pcb and between the said second means and the pcb and combinations thereof.
In especially preferred embodiments of the invention, the electrical connecting device will include an F-port connector for use in CATV distribution equipment which includes means for making electrical connections between first RF electrical signal providing means and first RF electrical signal receiving means to provide CATV services, and alternatively between second RF electrical signal and power providing means and second RF electrical signal and power receiving means to provide telephone services, and combinations thereof, said connector containing an inner resilient conductor member connectable to an electrical circuit when contacting a pcb contained in the housing; switching means operatively associated with the inner resilient conductor member and the pcb for selectively opening or closing an electrical connection between either the said first means or the said second means and the said combinations thereof when the inner resilient conductor member contacts the pcb,
wherein the inner resilient conductor member comprises: an electropin formed at its inlet end with a first pair of push pieces between which the internal conductor of a coaxial cable is connectable and retainable, an actuator pin portion which extends from the first pair of push pieces to a second pair of push pieces and a third pair of push pieces, and a capacitor arranged between the second and third pair of push pieces; and
wherein the switching means selectively switch the actuator pin to contact (a) the first and second pairs of push pieces, the capacitor and the pcb as a first mode; and (b) the first and third pairs of push pieces with the capacitor out of the circuit as the second mode or the connections and modes may be reversed.
The connecting device may also comprise a blocking capacitor mounted either inside the connector as described above or on a printed circuit board contained in the tap housing.
The connecting device may preferably comprise a tap housing which includes an F-port and any type of switching mechanism that will accomplish the desired purpose. It may include a first electrical half-connector or receptacle intended to provide signals and or power, and a second electrical half-connector or plug intended to receive power when mated with the receptacle and establishing connection between the components of the electrical circuit. The receptacle and plug assembly is preferably rotatable to switch between at least two inputs, and most preferably by separating , for example, by pulling, the outer or external half-connector and rotating it and subsequently again placing the half-connectors in mating position for example, by reinserting the external half-connector in mating relationship with the internal half-connector.
In other alternative embodiments, the connector may be of a single piece construction or the half-connectors may be two or more separate parts that separate or are caused to separate to effect switching between modes.
Switching may be accomplished by any means effective to make and break the circuit between the various modes such as, for example, a push/toggle device or a pin that pushes and moves an internal mechanism, The switch may be located inside the connector or on the pcb.
In another embodiment of the invention, the F-port is rotatable and comprises a first internal half-connector with a first RF socket position and a second RF with power socket position. An external half-connector with a male pin is mated in one of the socket positions. To switch between the two positions, the external half-connector is pulled from the assembly, rotated, and reassembled to mate in the desired socket position.
Alternatively, two or more wires connected by a switch and exiting the connector may be soldered to the pcb in the tap housing or in the connector; or the connector may have one wire which may exit the connector and be soldered to a pcb.
The blocking capacitor mounted inside the connector or on the pcb functions with the wires or pins in all of the embodiments to selectively make or break the selected circuit as desired.
AUTOMATICALLY TERMINATING CONNECTOR
The invention provides a means to automatically terminate the signal to the proper characteristic impedance when in the unmated state. The invention automatically terminates the input of an F-port connector when a cable and mating connector are not installed and thus eliminates the need to have a separate terminator available to install on unused F-ports.
According to the invention, termination of unused signals is accomplished automatically via a construction similar to that described above with respect to the SWITCHABLE CONNECTOR but wherein a plunger or actuator pin in the connector and a resistor which is spring loaded and making contact to ground and an RF line cooperate so that when the connector is screwed on or otherwise installed or connected to a mating connector, the plunger pushes the resistor, the circuit which is normally closed, is opened, and the signal flows. If the connector is unscrewed or otherwise removed or pulled out, the actuator pin moves out automatically terminating the signal.
Thus this part of the invention provides an automatically terminated electrical connector for making electrical connections between first electrical signal providing means and first electrical signal receiving means and/or alternatively between second electrical signal and power providing means and second electrical signal and power receiving means, and combinations thereof, said connector containing an inner resilient conductor member connectable to an electrical circuit when contacting circuit-providing means contained in the housing, such as a printed circuit board (pcb), means operatively associated with the inner resilient conductor member and the circuit-providing means for opening or closing an electrical connection between either the said first means or the said second means and the said combinations thereof when the inner resilient conductor member contacts the circuit-providing means, and means for terminating the signals when said inner resilient conductor member is not in contact with the circuit-providing means.
In preferred embodiments of the invention, the electrical connecting device is for use as an F-port in a cable television ("CATV") system which includes making electrical connections between first electrical signal providing means and first electrical signal receiving means to provide services including the provision of video and specifically, television, and alternatively between second electrical signal and power providing means and second electrical signal and power receiving means to provide services including telephone services, and combinations thereof, said connector containing an inner resilient conductor member connectable to an electrical circuit when contacting a pcb, means operatively associated with the inner resilient member and the the pcb for opening and closing the electrical connection between the said first means and a pcb and/or between the said second means and the pcb and combinations thereof when the inner resilient conductor member contacts the pcb, and means for terminating the signals when said inner resilient conductor member is not in contact with the pcb.
In especially preferred embodiments of the invention, the electrical connecting device will include an F-port connector for use in CATV distribution equipment which includes means for making electrical connections between first RF electrical signal providing means and first RF electrical signal receiving means to provide CATV services, and alternatively between second RF electrical signal and power providing means and second RF electrical signal and power receiving means to provide telephone services, and combinations thereof, said connector containing an inner resilient conductor member connectable to an electrical circuit when contacting a pcb contained in the housing; means operatively associated with the inner resilient conductor member and the pcb for selectively opening or closing an electrical connection between either the said first means or the said second means and the said combinations thereof when the inner resilient conductor member contacts the pcb,
wherein the inner resilient conductor member comprises: an electropin formed at its inlet end with a pair of push pieces between which the internal conductor of a coaxial cable is connectable and retainable, an actuator pin portion which extends from the pair of push pieces, and a resistor; and
wherein the signals are automatically terminated when said actuator pin is not in contact with said resistor.
The connecting device may preferably comprise a tap housing which includes an F-port and any type of contact/non-contact mechanism that will accomplish the desired purpose.
The connector may be of a single piece construction or it may be two or more separate parts that separate or are caused to separate to terminate the contact between the actuator pin and the resistor.
Termination may be accomplished by any means effective to make and break the circuit such as, for example, a push/toggle device or a pin that pushes and moves an internal mechanism.
The resistor may be mounted inside the connector or on the pcb functions with the wires or pins in all of the embodiments to make or break the selected circuit as desired.
In an alternative embodiment, the resistor may be mounted on a pc board and adapted so that the pin makes or breaks the circuit when it touches the board, or the pin can contact a membrane switch on a pc board that is normally closed. When the F-port connector on the customer's cable is screwed onto the connector, the actuator pin contacts the the switch and opens it thus removing the termination. The switch or pin is preferably spring loaded via a spring contact assembly so that when the connector is removed, the pin moves and the switch is closed thus terminating the F-port. Alternative means for switching between terminated and unterminated signals may also be employed such as toggle mechanisms, rotation mechanisms, etc.
Preferably, the connector is screwed into an aluminum die-cast tap housing as illustrated in FIG. 1 after which the pcb board is mounted from the opposite side of the connector and the connections are soldered onto the pcb.
In the field, installation is simple since it is only necessary to move the actuator pin by removing the mating connector to terminate the signals. The invention thus provides a device for use in distribution equipment which comprises a tap (splitter) housing which includes an F-port comprising an actuator pin mechanism that will automatically switch between terminated and unterminated.
In one preferred embodiment of the invention, the connector comprises a resistor mounted on a printed circuit board with two pins completing the electrical connection of the connector to the pcb and wherein at least one of the pins is spring loaded to assure good contact.
In another preferred embodiment of the invention, the connector comprises a resistor mounted in the connector housing with one or more pins extending from the connector to contact the pcb. In this case, the grounding is made inside the connector and includes spring loading (in the form of a spring or contact formed so as to provide a spring like effect) or to assure good grounding. In this embodiment also the actuator pin is preferably made of a material that will not degrade the electrical performance of the connector and is preferably formed of a plastic material.
SWITCHABLE AND AUTOMATIC TERMINATION CONNECTOR
In an especially preferred embodiment of the invention, the switching mechanism and the automatic termination mechanism described above are combined in a single construction. The tap housing containing the F-port may be installed in a CATV system to selectively supply telephone service to customers who subscribe to telephone service; and to provide only television service to customers who subscribe only to cable service. It permits the service provider to install a single connector whenever it installs cable television services and to subsequently add telephone service from outside the location of the services by rotation of the connector to connect and turn on the power required to operate the telephone to provide telephone services, and to automatically terminate the respective services when the service is not active.
In general, in accordance with the invention, there is provided an electrical connector for making electrical connections between first electrical signal providing means and first electrical signal receiving means and alternatively between second electrical signal and power providing means and second electrical signal and power receiving means, and combinations thereof, said connector containing an inner resilient conductor member connectable to an electrical circuit when contacting circuit-providing means contained in the housing, such as a printed circuit board (pcb), switching means operatively associated with the inner resilient conductor member and the circuit-providing means for selectively opening or closing an electrical connection between either the said first means or the said second means and the said combinations thereof when the inner resilient conductor member contacts the circuit-providing means; and means for terminating the signals when said inner resilient conductor member is not in contact with the circuit-providing means.
In preferred embodiments of the invention, the electrical connecting device is for use as an F-port in a cable television ("CATV") system which includes making electrical connections between first electrical signal providing means and first electrical signal receiving means to provide services including the provision of video and specifically, television, and alternatively between second electrical signal and power providing means and second electrical signal and power receiving means to provide services including telephone services, and combinations thereof, said connector containing the switching means comprising an inner resilient conductor member as described above for selectively making or breaking the electrical connection between the said first means and a pcb and between the said second means and the pcb and combinations thereof; and means for terminating the signals when said inner resilient conductor member is not in contact with the pcb.
In especially preferred embodiments of the invention, the electrical connecting device will include an F-port connector for use in CATV distribution equipment which includes means for making electrical connections between first RF electrical signal providing means and first RF electrical signal receiving means to provide CATV services, and alternatively between second RF electrical signal and power providing means and second RF electrical signal and power receiving means to provide telephone services, and combinations thereof, said connector containing an inner resilient conductor member connectable to an electrical circuit when contacting a pcb contained in the housing; switching means operatively associated with the inner resilient conductor member and the pab for selectively opening or closing an electrical connection between either the said first means or the said second means and the said combinations thereof when the inner resilient conductor member contacts the pcb;
wherein the inner resilient conductor member comprises: an electropin formed at its inlet end with a first pair of push pieces between which the internal conductor of a coaxial cable is connectable and retainable, an actuator pin portion which extends from the first pair of push pieces to a second pair of push pieces and a third pair of push pieces, and a capacitor arranged between the second and third pair of push pieces;
wherein the switching means selectively switch the actuator pin to contact (a) the first and second pairs of push pieces, the capacitor and the pcb as a first mode; and (b) the first and third pairs of push pieces with the capacitor out of the circuit as the second mode or the connections and modes may be reversed. connecting device which comprises means for selectively making electrical connections between either first electrical signal providing means and first electrical signal receiving means and second electrical signal and power providing means and second electrical signal and power receiving means, and combinations thereof, and means for automatically terminating unused signals therein;
wherein the inner resilient conductor member also comprises at least one an actuator pin portion which extends from the first pair of push pieces, and a resistor; and
wherein the signals are automatically terminated when said actuator pin is not in contact with said resistor.
The connecting device of this embodiment of the invention may be formed by combining the various aspects of the invention as described hereinabove into a single device which comprises a F-port connector having a housing which comprises, a first electrical half-connector or receptacle intended to provide signals and or power, and a second electrical half-connector or plug intended to receive power when mated with the receptacle and establishing connection between the components of the electrical circuit, wherein the receptacle and plug assembly is preferably rotatable to switch between at least two inputs, and most preferably by separating , for example, by pulling, the outer or external half-connector and rotating it and subsequently again placing the half-connectors in mating position for example, by reinserting the external half-connector in mating relationship with the internal half-connector. The connecting device also comprises a blocking capacitor and a resistor mounted either inside the connector or on a printed circuit board contained in the tap housing. A plunger or actuator pin in the connector and the resistor cooperate so that when the connector is screwed on, the plunger pushes the resistor, the circuit is opened, and the signal flows. If the connector is unscrewed, the actuator pin moves out automatically terminating the signal.
In other alternative embodiments, the connector may be of a single piece construction or the half-connectors may be two or more separate parts that separate or are caused to separate to effect switching between modes and to automatically terminate the undesired signals.
The connecting device of the invention may be formed from materials well known in the art. For example, to avoid corrosion in the rotating area of the connector, suitable materials for the connector are nickel/zinc alloy with yellow chromate containing about 6-10% alkaline-type Ni. Also, to ensure water-tightness, it is preferred to use an "o" ring between the inner and outer shells of the conductor. When employed, the "o" ring is installed in a groove and gently presses against the inner and outer shells providing a water tight seal.
It will be understood that the electrical connector may be of various and differing shapes in addition to that illustrated and described for ease of discussion above and still provide the advantages of the invention.
It will also be understood that the invention contemplates structures where the connector is a single connector or an internal half-connector and external half-connector or combinations thereof or structures where internal and external half-connectors are employed where the internal half-connector is the receptacle or socket and where the external half-connector is the plug as described and illustrated herein, as well as structures where the relationship is reversed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an illustration of a tap unit;
FIG. 2 is a perspective view of distribution equipment provided with a connector of the invention;
FIG. 3 is a perspective view of a connecting device of the invention;
FIG. 4 is a sectional view of a switchable connecting device of the invention taken along lines 2--2 of FIG. 3;
FIG. 5 is a sectional view similar to that of FIG. 4 illustrating a second embodiment of a switchable connecting device of the invention;
FIG. 6 is a sectional view similar to that of FIG. 4 illustrating an automatically terminating connecting device of the invention;
FIG. 7 is a sectional view similar to that of FIG. 6 illustrating a second embodiment of an automatically terminating connecting device of the invention; and
FIG. 8 is a perspective view of a switchable and self-terminating connecting device of the invention having a rotatable portion; and
FIG. 9 is a sectional view of a switchable and automatically terminated connecting device of the invention taken along line 9--9 of FIG. 8.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
F-type end connectors and ports, and/or systems with a single switchable connecting device or with a single automatically terminating connecting device, or with one or more switchable connecting devices combined with one or more automatically terminating devices and any other combination thereof may be considered as part of the context or environment of this invention, or to the extent recited in the appended claims may be elements of the inventive combination.
With reference to FIGS. 1 and 2, there is illustrated a typical outdoor tap or distribution equipment having a housing or casing 1, a output 11 and an input 12. An outer cylindrical F-port connector 13 with threaded zones 14 formed on its outer periphery to which an outer braid conductor 31 of a coaxial cable 30 is connectable through a nut 32 fixed to a wall surface of the housing 1. The outer braid conductor 31 functions as a grounding conductor, which is inserted conductively in a nut 32. Referring now to FIGS. 3 to 5, the port connector 13 comprises an outer conductor 13a. While the outer conductor 13a is formed integrally with the housing 1 in the example, it can be formed from a member other than the housing and then fixed to the housing 1. The outer conductor 13a also includes a rotatable portion 13b at its central portion. The outer conductor 13a has an inlet end 16 (and into which the internal conductor of the coaxial cable is inserted) and a distal or mounting side to the housing 1 so that the insulator 15 can be inserted easily for assembly. A substantially hollow cylindrical insulator 15 comprising a plastic tube 15a inserted and retained to come in contact with the inner wall surface of the outer conductor 13a and holding an inner resilient conductive member 21 at the central portion is inserted and so retained in the outer conductor 13a of the F-port connector 13.
The inner resilient conductive member 21 comprises an electropin 5 which is formed at its inlet end with a pair of push pieces 21a between which the internal conductor 33 of the coaxial cable 30 is inserted and so retained, an actuator pin 21b which extends from the push pieces 21a to two pairs of push pieces 21c and 21d, and a capacitor 21e situated between the pair of push pieces 21c and 21d. Preferably, the two pairs of push pieces 21c and 21d are preferably set equidistant from the center and approximately 180° from each other. At the distal end 18, the electropin 5 is connected to a pc board shown diagrammatically at 40.
Upon assembly of the connector for connection to distribution equipment, the internal conductor 33 of the coaxial cable is inserted through the hole 15b of the F-port connector 13 between the paired push pieces 21a of the inner resilient conductive member 21. The actuator pin 21b is inserted between the paired push pieces 21c which are operatively associated with the capacitor 21e so that when the actuator pin 21b is in contact therewith, the circuit is opened, and both the signal and power flow. When it is desired to switch the connector to a different mode, for example where only the RF signal is provided, the connector is rotated via rotatable piece 13b causing movement of the actuator pin 21b from the push pieces 21c and insertion thereof in the push pieces 21d. In this position, the capacitor 21e blocks operation of the distribution equipment in the first mode. To switch the connector back to the first mode, it is only necessary to rotate the rotatable piece 13b to remove the actuator pin from the push pieces 21d and to insert the actuator pin into the push pieces 21c. One means for effecting rotation of the rotatable piece 13b may be as illustrated in FIG. 8 wherein an alignment pin 42 is pushed in to release the actuator pin from the respective push piece, the rotatable piece is rotated to move the pin 21 in the alignment slot 43 and is fixed in the other push piece upon release of the alignment pin.
With reference to FIGS. 3 and 5, in an alternative embodiment of the invention, the switch is mounted on the pc board and is normally in the open position to supply only RF signals to the F-port. To supply both RF and power, an actuator pin 21b is installed into the end 15 of the F-port through push pieces 21a of resilient member 21 and at its distal end 18, contacts contact button 22 and thus activates a switch on the pc board. Alternatively, there may be a plurality of contact buttons on the pc board with one or more actuator pins completing the circuit or circuits being switchable into and out of contact depending on the service that is to be provided.
Similarly, with reference to FIGS. 3, 6 and 7, there is illustrated an outer cylindrical F-port connector 13 with threaded zones 14 formed on its outer periphery to which an outer braid conductor 31 of a coaxial cable 30 is connectable through a nut 32 fixed to a wall surface of the tap housing 1 as discussed above. The port connector 13 comprises an outer conductor 13a which may be formed integrally with the housing 1 as in the example, or it can be formed from a member other than the housing and then fixed to the housing 1. The outer conductor 13a may also include a rotatable portion 13b at its central portion although this construction is optional and is not mandatory. The interior of the outer conductor 13a is preferably formed with its inner diameter gradually increasing toward an inlet end 16 (and into which the internal conductor of the coaxial cable is inserted) from a mounting side to the housing 1 so that the insulator 15 can be inserted easily for assembly. A substantially hollow cylindrical insulator 15 comprising a plastic tube 15a inserted and retained to come in contact with the inner wall surface of the outer conductor 13a and holding an inner resilient conductive member 21 at the central portion is inserted and so retained in the outer conductor 13a of the F-port connector 13.
The inner resilient conductive member 21 comprises an electropin 5 which is formed at its inlet end with a pair of push pieces 21a between which the internal conductor 33 of the coaxial cable 30 is inserted and so retained, an actuator pin 21b which extends from the push pieces 21a, and a resistor 21f which is spring loaded and making contact to ground and to a RF line. At the distal end 18 of the conductor 13, the electropin 5 is connected to a pc board shown diagrammatically at 40.
Upon assembly of the connector for connection to distribution equipment, the internal conductor 33 of the coaxial cable is inserted through the hole 15b of the F-port connector 13 between the paired push pieces 21a of the inner resilient conductive member 21 to contact the actuator pin 21b. The paired push pieces 21a are operatively associated with the resistor 21f and a membrane switch is present on the pc board. This switch is normally closed. When the F-port connector on a customer's cable is screwed onto the F-port connector 13 of the invention, the actuator pin 21b thus contacts the switch, opens it and thus disconnects the resistor removing the termination. Because the actuator pin 21b is spring loaded, when the connector is removed, the pin 21b will be removed and the switch will close thus automatically terminating the F-port.
In the alternative embodiment shown in FIG. 7, the resistor is mounted on the pc board and a plurality of electropins 5 and 5a, with a spring loaded contact 24 situated between them, are employed to complete the circuit or circuits being switchable into and out of contact depending on the service that is to be provided.
With reference to FIGS. 8 and 9, there is illustrated an embodiment of the invention which combines the various aspects of the invention as described hereinabove into a single device in which the F-port connector 13 comprises a first electrical half-connector or receptacle intended to provide signals and or power, and a second electrical half-connector or plug intended to receive power when mated with the receptacle and establishing connection between the components of the electrical circuit, wherein the receptacle and plug assembly is preferably rotatable via alignment pin 42 in alignment slot 43 to switch between at least two inputs, and most preferably by separating , for example, by pulling, the outer or external half-connector and rotating it and subsequently again placing the half-connectors in mating position for example, by reinserting the external half-connector in mating relationship with the internal half-connector. A blocking capacitor and a resistor are mounted either inside the connector or on a printed circuit board contained in the tap housing 1. The actuator pin in the connector and the resistor cooperate so that when the connector is screwed on, the plunger or actuator pin pushes the resistor, the circuit is opened, and the signal flows. If the connector is unscrewed, the actuator pin moves out automatically terminating the signal. The blocking capacitor mounted inside the connector functions as described above to make or break the circuit as desired when switching between the desired modes.
It will be understood that the connecting device of the invention need not and should not be limited to use as an F-port connector for coaxial television cables and is suitable for connecting wires of different types of devices together when it is desired to provide for automatic termination of signals or for switching between various circuits.
It will also be understood that the invention contemplates structures where the connector is a single connector or an internal half-connector and external half-connector or combinations thereof or structures where internal and external half-connectors are employed where the internal half-connector is a receptacle or socket and where the external half-connector is a plug, as well as structures where the relationship is reversed.
The invention may be embodied in other specific forms without departing from the spirit and scope or essential characteristics thereof, the present disclosed examples being only preferred embodiments thereof. | An electrical connector for automatically terminating signals in distribution equipment is provided, particularly in the form of a tap housing containing the F-port connector installed in a CATV system. The connector includes a cylindrical outer conductor for attachment to a housing of the distribution equipment which contains a pcb, a conductor of a coaxial cable being connectable to said outer conductor; an inner resilient conductor member contained in the outer conductor and connectable to an electrical circuit when contacting the pcb, a conductor of a coaxial cable being connectable to the inner resilient conductor member; and signal terminating means comprising a resistor operatively associated with the resilient conductor member and the pcb whereby an electrical circuit may be selectively opened and closed to automatically terminate the signals when the inner resilient conductor member has contact with the pcb. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S. provisional patent application No. 60/553,585, filed Mar. 16, 2004, hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a recreational board, such as a snowboard, a surfboard, skis, and the like, and more particularly to a multiple-section recreational board, which can be easily disassembled to facilitate transport and reassembled quickly and easily while providing sufficient structural integrity.
[0004] 2. Description of the Prior Art
[0005] Various multiple-section snowboards and skis are known in the art. For example, U.S. Pat. Nos. 2,545,209; 3,026;546; 3,439,928; 3,797,838; 3,819,198; 3,825,360; 4,155,568; 4,458,912; 4,593,926; 4,600,211; 4,645,228; and 4,723,789 all disclose multiple-section skis that are split along a transverse axis. Such multiple-section skis facilitate transport. Unfortunately, the multiple-section skis disclosed in these patents are relatively complicated and are not user-friendly.
[0006] Other known examples of such multiple-section skis are disclosed in U.S. Pat. Nos. 3,104,888; 4,358,130; 4,632,418 and 6,616,170. Unfortunately, the connection mechanisms in these devices are relatively complicated making the skis relatively complex and thus expensive to manufacture and repair.
[0007] U.S. Pat. No. 5,711,692 relates to a multiple-section surfboard. Contiguous sections of the surfboard are coupled together with a rod arrangement. More particularly, one section of the surfboard is provided with a rod extending outwardly from the width of the surfboard and disposed along the board's longitudinal axis. The other section of the surfboard is provided with an elongated hole for receiving the rod. The arrangement is configured so that when the rod is received in the elongated hole, the contiguous sections of the surfboard are aligned. A latch device is provided to latch the two contiguous sections together. Although such an arrangement for coupling together multiple sections of a surfboard may provide acceptable performance-for a surfboard, such a configuration is not appropriate for recreational boards where the forces involved can be expected to be relatively high.
[0008] Thus, there is a need for a multiple-section recreational board that is user-friendly and is also relatively less complicated and thus less expensive to manufacture and is suitable for applications in which the expected forces are relatively high.
SUMMARY OF THE INVENTION
[0009] Briefly, the present invention relates to a multiple-section recreational board, such as a snowboard, surfboard, skis, or the like. The multiple-section recreational board may be formed in two or more sections. Contiguous sections of the recreational board are coupled together by one or more bridges in order to provide sufficient structural integrity generally equivalent to or greater than a one-piece recreational board. The board sections may be latched together by one or more latch mechanisms that are relatively simpler than known latch mechanisms. The latch mechanisms may be either separate devices or integrally formed with the bridge. In accordance with one aspect of the invention, the multiple-section recreational board is relatively easily disassembled and reassembled and is relatively less complex to manufacture than known multiple section recreational boards.
DESCRIPTION OF THE DRAWING
[0010] These and other advantages of the present invention will be readily understood with reference to the following specification and attached drawing wherein:
[0011] FIG. 1 is a top view of an exemplary embodiment of a two piece recreational board in accordance with the present invention that has been joined together with a bridge consisting of a plate and a number of fasteners.
[0012] FIG. 2 is an isometric view of the two-piece recreational board illustrated in FIG. 1 .
[0013] FIG. 3 a is a top view of an alternate embodiment of a bridge that may be used to join contiguous sections of a recreational board together in accordance with the present invention.
[0014] FIG. 3 b is a side view of the bridge illustrated in FIG. 3 a.
[0015] FIG. 3 c is an end view of the bridge illustrated in FIG. 3 a.
[0016] FIG. 4 a is another alternate embodiment of a bridge that may be used to join contiguous sections of a recreational board together in accordance with the present invention.
[0017] FIG. 4 b is a side view of the bridge illustrated in FIG. 4 a.
[0018] FIG. 4 c is an end view of the bridge illustrated in FIG. 4 a.
[0019] FIG. 4 d is a sectional view along line 4 d - 4 d of FIG. 4 a.
[0020] FIG. 4 e illustrates a multiple-section recreational board with a plurality of bridges illustrated in FIG. 4 a.
[0021] FIG. 5 is an isometric view of another alternate embodiment of a bridge that may be used to join split sections of a recreational board together in accordance with the present invention, shown mounted on a portion of a recreational board in a disassembled position.
[0022] FIG. 6 is similar to FIG. 5 but illustrating a smooth covering for the bridge.
[0023] FIG. 7 illustrates an alternate embodiment of the bridge illustrated in FIG. 5 but with an integral latch mechanism.
[0024] FIG. 8 is an isometric view of another alternate embodiment of a bridge that may be used to join contiguous sections of a recreational board together in accordance with the present invention, shown mounted on a portion of a recreational board in a disassembled position and also illustrating an separate exemplary latch mechanism.
[0025] FIGS. 9 a and 9 b are isometric views of another alternate embodiment of a bridge that may be used to join split sections of a recreational board together in accordance with the present-invention, shown in an assembled and disassembled positions, respectively.
[0026] FIGS. 10 a and 10 b are isometric views of another alternate embodiment of a bridge with an integral latch that may be used to join contiguous sections of a recreational board together in accordance with the present invention, shown in an assembled and disassembled positions, respectively.
[0027] FIG. 11 a is an isometric view of an alternate bridge with an integral latch for use with the present invention, shown in a latched position.
[0028] FIG. 11 b is similar to FIG. 11 a but shown in a disassembled position.
[0029] FIG. 11 c is similar to FIG. 11 a but shown in an intermediate unlatched position.
DETAILED DESCRIPTION
[0030] The present invention relates to a multiple-section recreational board. Although the invention is described and illustrated with respect to a multiple-section snowboard, the principles of the present invention are also applicable to multiple-section skis, as well as multiple-section surfboards, for example, as described in U.S. Pat. No. 5,711,692. As used herein, multiple section recreational board refers to all types of recreational boards including snowboards, surfboards, skis and the like. Moreover, although the multiple-section recreational board is shown and illustrated split into just two sections, the principles of the present invention also relate to recreational boards that are split into more than two sections, for example, three sections or more.
[0031] Turning to the drawing, FIGS. 1 and 2 illustrate the simplicity of the invention. In particular, a basic concept of the bridge in accordance with the present invention is configured as a plate with a number of through holes and a plurality of fasteners. In particular, FIGS. 1 and 2 illustrate a recreational board, such as a snowboard, generally identified with the reference numeral 20 , that has been split into two sections 22 and 24 , for example. As shown best in FIG. 2 , the two sections 22 and 24 are placed together defining a joint 26 .
[0032] As shown in FIG. 2 , the joint 26 is shown cut at a straight vertical angle; generally ninety (90) degrees from the plane of the recreational board sections 22 and 24 . It should also be understood that the joint 26 can be formed with an angled cut and that other types of joints are also considered to be within the broad scope of the invention, such as dovetail and other types of joints common in the woodworking industry.
[0033] As shown in FIGS. 1 and 2 , a plate 28 is used as a one-piece bridge to secure the two recreational board sections 22 and 24 together. The one-piece bridge 28 does not require a latch since the plate is securely fastened to both sections 22 , 24 of the recreational board. The plate 28 is juxtaposed to span the joint 26 and is attached to the recreational board sections 22 and 24 by way of a number of fasteners, generally identified with the reference numeral 30 . As shown, the plate 28 bridges the joint 26 and strengthens the joint 26 so that its structural integrity, such as its resistance to vertical shear force, is generally the same or greater than a one-piece recreational board.
[0034] Alternate embodiments of the bridge are illustrated in FIGS. 3 a - 3 c and 4 a - 4 e , identified generally with the reference numerals 32 and 34 , respectively. The embodiments of the bridge illustrated in FIGS. 3 a - 3 c , 4 a - 4 c , 5 - 8 , 9 a - 9 b , 10 a - 10 b and 11 a - 11 c are configured as two-piece complementary coupling devices. Returning to FIGS. 3 a - 3 c and 4 a - 4 c , both bridges 32 and 34 emulate the plate 28 and act to bridge the joint 26 ( FIG. 2 ) between contiguous recreational board sections 22 and 24 . These bridges 32 and 34 sufficiently strengthen the recreational board sections such that the assembled recreational board can withstand at least as high of a shear force as a one-piece recreational board without damage.
[0035] Both of the bridge designs 32 , 34 illustrated in FIGS. 3 a - 3 c and FIGS. 4 a - 4 d , respectively, are adapted to be carried on the surface of the split recreational board sections, for example, sections 36 and 38 ( FIG. 4 e ). These bridges 32 and 34 are positioned over split sections of the recreational board so as to span the joint 26 .
[0036] Referring to FIGS. 3 a - 3 c , the bridge 32 is formed from essentially two parts: a first bridge member 42 carrying a male shank 44 and a second bridge member 40 formed as a complementary female receptacle 41 ( FIG. 3 c ). The first bridge member 42 is secured to one recreational board section (not shown) while the second bridge member 42 is secured to another recreational board section. The bridge members 40 , 42 are configured so that when the recreational board sections are placed together, the male shank 44 on the bridge member 42 will be inserted into the female receptacle 41 , forming a bridge across the joint.
[0037] An alternate embodiment of a bridge is illustrated in FIGS. 4 a - 4 d and generally identified with the reference numeral 34 . FIG. 4 e illustrates an exemplary embodiment in which multiple bridges 34 are attached to the recreational board sections 36 and 38 .
[0038] The bridge 34 includes two parts: a first bridge member 50 and a second bridge member 52 . The first bridge member 50 is rigidly secured to one section of the recreational board and includes an extending male shank 54 . The first and second bridge members 50 , 52 are configured so that the male shank 54 is received in a complementary female receptacle 56 ( FIG. 4 d ) formed in the second bridge member 52 . As shown in FIG. 4 e , the bridges 34 are positioned to span across the joint 57 between the contiguous sections 36 and 38 of the recreational board.
[0039] Another alternate embodiment of the bridge, in accordance with the present invention, is illustrated in FIG. 5 and generally identified with the reference numeral 60 . The bridge 60 includes a first bridge member 62 and a second bridge member 64 . The bridge member 62 is formed as a generally elongated rectangular member 62 with an extending shank 76 . In order to enable the bridge members 62 , 64 to be secured to the recreational board, each bridge member 62 , 64 is formed with one or-more flanges 66 . Each flange 66 is provided with a through hole for receiving a fastener 68 to enable the flange 66 and thus the bridge member 62 , 64 to be fastened to a section of the recreational board.
[0040] The bridge member 62 is positioned on section 70 of the recreational board so that a longitudinal axis 78 of the elongated member 74 is generally parallel to a longitudinal axis 80 of the section 70 of the recreational board. In addition, the bridge member 62 is generally placed against an edge 82 of the recreational board section 70 such that the extending shank 76 extends outwardly therefrom.
[0041] The bridge member 64 generally includes a generally rectangular elongated member with a hole 86 defining a receptacle for the male shank 76 . The bridge member 64 may be formed with one or more flanges 92 . The flanges 92 are each provided with an aperture for receiving a fastener 94 to enable the bridge member 64 to be secured to the recreational board section 72 . The bridge member 64 is similarly juxtaposed on the recreational board section 72 such that its longitudinal axis 88 is generally parallel to a longitudinal axis 90 of the recreational board section 72 . The bridge member 64 is secured to the recreational board.
[0042] The rectangular shape of the bridge members 62 -and 64 , as well as the male shank 76 , are merely exemplary. Virtually any cross-sectional area for the bridge member 62 and 64 are possible so long as the cross-section has a generally planar surface along its longitudinal axis to allow the bridge members 62 , 64 to lay generally flat against the recreational board sections 70 , 72 . For example, semi-circular, triangular as well as well as other polygonal cross-sections are considered to be within the broad scope of the invention.
[0043] Similarly, the cross-sectional area of the male shank 76 is also exemplary. Various cross-sectional areas for the metal shank 76 are considered to be within the broad scope of the present invention. For example, the cross-sectional area of the metal shank 76 may be other than rectangular or square. Indeed, circular, irregular and various polygonal cross-section are considered to be within the broad scope of the invention. It is only necessary that the receptacle formed in the bridge member 64 be either complementary or otherwise configured to receive the male shank 76 .
[0044] An exemplary embodiment of a snowboard constructed in accordance with the present invention may include virtually any snowboard, cut, for example, in two generally equal-length sections. The bridge 60 may be formed from various materials including virtually any metal, such as, steel, aluminum or titanium, as well as other materials which provide the requisite strength, such as, plastic and composite materials and the like. The bridge 60 may be formed as a generally square member 74 , for example, a generally square steel bar, having a length of, for example, about 5 to 8 inches and a cross-section of, for example ¼ inch to 4 inches, depending on the material. The bridge member 62 may be formed as an elongated solid member having a portion with a reduced cross sectional area forming the shank 76 . The bridge member 64 is formed in a similar manner but with an elongated hole, formed to receive the male shank 76 .
[0045] The flanges 66 , 92 may be formed from the same material as the bridge members 62 , 64 and either integrally formed with the bridge members 62 , 64 or attached thereto by various well known methods, as shown, and configured to enable the bridge to be flush mounted on a surface of the board sections 70 , 72 . The flanges 66 , 92 may be, for example, from ½ inch to the length of the bridge members 60 , 62 and have a thickness, for example 1/16 inch to 1 inch depending an the required strength. The flanges 66 , 92 may be provided with a through hole for receiving a ⅛ to ¾ inch fastener.
[0046] The configuration of the bridge 60 , as generally illustrated in FIG. 5 , may be configured with the following exemplary characteristic. For example, the bridge 60 may be configured to carry a 225 pound person, standing mid board. Assuming 3 point bending, a force of 1.5 g's, and a length L =1.22 meters, the force at the midpoint, M(L/2)=F/2*L/2=225/2.2 kilograms*1.5*9.81 meters/sec 2 =1505 Newtons. Assuming the board is 0.01 meters thick and the bridge 60 is mounted on top of the board and the moment of inertia I= 1/12 b*h 3 , where the base of the board b=0.27 meters and the height of the board h=0.01 meters, the stress=My/I=1505N*(0.01/2)m/(2.25e-8m 4 )=103e6 N/m 2 , the torque=F/2*b/2=102 Newton meters, the shear=F/4=376 Newtons and the pull axial=shear=F/4=376 Newtons.
[0047] The material and size of the material used for the bridges and shank can be used to give the boards different mechanical/performance characteristics. Moreover, the bridges may be designed such that the shanks/bridges are interchangeable to allow the board characteristics to be changed by the user/rider. For example, such a configuration may be used to allow the end user to change the shanks on the bridge so that the board can be tuned, for example, for different snow conditions.
[0048] FIG. 6 illustrates another alternate embodiment of the bridge, generally identified with the reference numeral 92 . In this embodiment, the bridge is formed by a pair of complementary bridge members 94 and 96 and is similar to the embodiment illustrated in FIG. 5 and identified with the references numeral 60 . The main difference is that the bridge members 94 and 96 are formed with a generally smooth surface. The smooth surface may be formed by many well-known techniques including over-molding of the bridge members 62 , 64 , which may be done at the time the recreational board is laminated or afterwards, for example, by covering the bridges with a composite or other material. Such a configuration enables the bridge members 92 and 94 to be used, for example, for surfboards.
[0049] FIG. 7 illustrates another alternate embodiment of a bridge in accordance with the present invention which incorporates an integral latch. This embodiment is generally identified with the reference numeral 98 and is similar to the bridge members 62 , 64 , discussed above. The bridge 98 includes a first bridge member 100 and a second bridge member 102 . The bridge member 100 includes a generally elongated member 104 and an extending shank 106 . In this embodiment, the extending shank 106 is formed with a notch 112 at one end. The bridge member 100 is formed with one or more flanges 108 to enable the bridge member 100 to be secured to a section of a recreational board by way of one or more fasteners 110 .
[0050] The bridge member 102 includes an elongated member 114 that is formed with an elongated hole 116 for receiving the male shank 106 . The bridge member 102 also includes one or more flanges 118 to enable the bridge member 102 to be secured to a section of a recreational board by way of one or more fasteners 120 .
[0051] An exemplary moveable latch key 122 with an extending tongue 124 may be provided at one end. In this embodiment, the bridge member 102 is provided with a slot (not shown) for receiving the latch key 122 . More particularly, the elongated member i 14 is configured such that the extending tongue 124 on the latch key 122 is in communication with the elongated hole 116 . In an unlatched position, the extending tongue 124 on the latch key 122 is removed from the elongated hole 116 in the elongated member 114 . Once the male shank 106 is inserted into the elongated hole 116 , the latch key 122 can be juxtaposed so that the extending tongue 124 is captured in the notch 112 formed in the male shank 106 to prevent axial movement bridge member 100 with respect to the bridge member 102 .
[0052] The latch key 122 may either be pivotally mounted on one end to enable the extending tongue 124 to be rotated into and out of communication with the elongated hole 116 . In rotational embodiments, a torsion spring may be provided to bias the latch key 122 in a latched position as generally shown in FIG. 7
[0053] An alternate embodiment of the invention is illustrated in FIG. 8 . In this embodiment, an alternate bridge is illustrated and generally identified with the referenced numeral 130 . The bridge 130 includes a first bridge member 132 and a second bridge member 134 . The bridge member 132 may be formed as a generally egg-shaped member 136 that is truncated at one end. In this embodiment, the underside of the bridge member 132 may be provided with threaded holes (not shown) that are adapted to be aligned with holes (not shown), for example, counter-sunk holes, formed in the underside of the recreational board section 140 . Such a configuration allows the bridge member 132 to be secured to the recreational board section 140 respectively by way of fasteners (not shown) that are inserted into the underside of the recreational board section 140 .
[0054] The bridge member 132 is formed with an extended male shank 140 . The extended male shank 140 may be formed with a generally circular cross section. The bridge member 132 is juxtaposed on the recreational board section 140 so that a longitudinal axis 144 of the extended metal shank 140 is generally parallel with a longitudinal axis 146 of the recreational board section 140 .
[0055] The bridge member 134 is similarly formed With a generally egg-shaped member 146 truncated at one end, which may be juxtaposed relative to the recreational board section 138 and connected and rigidly secured thereto in the same manner as discussed above. The bridge member 134 is provided with a central hole 148 defining a female receptacle for receiving the extended male shank 142 .
[0056] In the embodiment illustrated in FIG. 8 , a separate exemplary latch mechanism 150 is utilized. The latch mechanism 150 may include a catch 148 , rigidly attached one of the recreational board sections 138 , 140 . The catch 148 is formed with a generally horizontal bar. When the recreational board section 138 , 140 are placed together the catch is adapted to be captured by a latch mechanism 150 rigidly secured to the adjoining or contiguous section 138 of the recreational board. The latch mechanism 150 includes an extending lever 152 which is hooked at one end. The hooked end of the lever 152 is adapted to capture the horizontal bar of the catch 148 . The lever 152 is pivotally mounted to a second lever 154 , which, in turn, is pivotally mounted to a base member 156 . When the sections 138 , 140 of the recreational board are placed together, the hooked portion of the lever 152 captures the horizontal rod on the catch 148 . The other lever 154 is then rotated in a counter clockwise direction until the latch mechanism 156 is in a latched position.
[0057] An alternate bridge in accordance with the present invention is illustrated in FIGS. 9 a and 9 b and generally identified with the referenced numeral 160 . The bridge 160 includes a first bridge member 162 and a second bridge member 164 . For added stability, the bridge members 162 and 164 may be formed with keels 166 and 168 respectively. These keels 166 , 168 are adapted to be received in elongated slots (not shown) formed in the sections of the recreational board. Each bridge member 166 , 168 is formed with a flange 170 on each side. The flanges 170 , 172 are configured with through holes (not shown) for receiving fasteners to fasten the bridge members 162 , 164 to the sections of the recreational board.
[0058] The bridge member 162 includes an extended flange portion 174 , formed as a generally rectangular plate. The extended flange portion 174 is configured to be received in a slot 176 formed in the bridge member 164 . The bridge member 162 also includes a vertical plate portion 178 . The vertical plate portion 178 provides additional strength to the bridge 160 .
[0059] FIGS. 10 a and 10 b illustrate an alternate embodiment of the bridge, generally identified with the reference numeral 180 . The bridge 180 includes a bridge member 182 and a bridge member 184 . The bridge member 182 is formed with an irregular shape having a generally smooth surface with an extending male shank 186 . The bridge member 182 includes a pair of flanges 188 and 190 . The flanges 188 and 190 are formed with through holes 192 for receiving fasteners (not shown) to enable the bridge member 182 to be secured to a section of a recreational board.
[0060] The bridge member 184 includes a generally irregular shape, smooth base member with an elongated hole 194 . The elongated hole 194 defines a receptacle for receiving the extended male shank 186 . The bridge member 184 also includes a flange 196 and 198 on each side. The flanges 196 , 198 are provided with through holes 200 to enable the bridge member 184 to be secured in place with fasteners (not shown).
[0061] The bridge 180 may also be formed with an integral latch mechanism 202 . The latch mechanism 202 may be formed from a pair of slots 204 , 206 which may be formed on each side of the bridge members 182 and 184 . A flexible metal strap 208 with hooked ends may be used to secure bridge members 182 and 184 together.
[0062] An alternate bridge with an integral latch is illustrated in FIGS. 11 a - 11 c and generally identified with the reference numeral 210 . The bridge 210 includes a bridge member 212 and a bridge member 214 . These bridge members 212 , 214 may be formed with threaded holes on the underside to enable the members 212 , 214 to be fastened to sections of a recreational board with suitable fasteners (not shown).
[0063] The bridge member 212 is formed with a base section 216 and on extending shank 218 . An irregular shaped latch member 220 is formed at the end of the extending shank 218 . The extending latch member 220 is formed with a generally circular cross section with a planar surface.
[0064] The latch member 220 is adapted to be received in a pair of irregularly shaped notches 220 , 224 formed in the bridge member 214 . As best shown in FIG. 11 c, the recreational board sections are brought together, the sections of the recreational board are manipulated so that the bridge member 212 (including the recreational board section to which it is attached) is rotated upwardly to allow the latch member 22 to be received into the irregularly shaped notches 220 , 224 in the bridge member 214 . As the bridge member 212 is rotated in a clockwise direction the latch member 220 becomes captured within the regular shaped notches 222 , 224 to its latched position as shown in FIG. 11 a.
[0065] The bridge member 212 may be provided with a deadbolt 226 which is slideably received within the bridge member 212 . The deadbolt 226 is adapted to be received in a generally square aperture in a bow portion 228 of the bridge member 214 .
[0066] The bridge members 212 and 214 may be formed with threaded apertures (not shown). These threaded apertures may be aligned through holes formed in sections of the recreational board to enable the bridge members 212 , 214 to be secured thereto.
[0067] Obviously, many modifications and variations of the present invention are possible in light of the above teachings. Thus, it is to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described above. | A multiple-section recreational board is formed in two or more sections. Contiguous sections of the recreational board arc coupled together by one or more bridges which provide the structural integrity generally equivalent to an integral one piece recreational board. The bridges may be latched by an integral or separate latch mechanism. In accordance with one aspect of the invention, the multiple-section recreational boards are relatively easily disassembled and reassembled and are relatively less complex to manufacture than known multiple-section recreational boards. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to flooring for a building, and more specifically to flooring washable at its installation place in a building.
2. Description of the Related Art
Flooring for a building which requires water washing is formed, in most cases, through a series of steps: applying leveling mortar to a concrete floor slab, coating it with asphalt, forming a presser mortar layer, forming a cinder concrete layer, applying mortar as tile bedding, and finishing with tiles. The flooring formed through such steps is excellent in its water-proofness. On the other hand, it requires a quite long time in forming, which gives a major factor in prolonging construction period. Moreover, an enormous cost is required to repair the flooring even if it is partial damage.
Then, the inventors of the present invention have proposed a flooring structure capable of solving the problem described above.
The invention concerned is, as disclosed in Japanese Patent Publication No. 2539709, a flooring structure in which floor panels are arranged above a floor slab surface to effectively drain the water sprinkled on the floor panels.
To be specific, a joint member is placed between every adjacent floor panels out of a plurality of floor panels set on a plane, and joist members are arranged to support the right and left edges of the respective floor panels. Sleeper members for supporting the joist members are further arranged perpendicular to the joist members, and water communication holes are provided to communicate the joist members and the sleeper members.
One water communication hole consists of a hole formed in one joist member and a hole formed in the associated sleeper member which coincide with each other. Each joist member has a flange to prevent waste water from leaking outside.
A drain pipe for draining water flown therein from between the floor panel and the joint member is provided on an end of each sleeper member.
Strut members for supporting the sleeper member are arranged on the bottom surfaces of both ends of each sleeper member, and are grounded on the floor slab surface of the building so that the entire members are held.
A cylindrical ventilation body is connected to each sleeper member so that no smell stays in a space above the flooring as well as the interior of the sleeper member and the joist member is dried.
The structure described above makes it possible to assemble, with a simple construction, flooring capable of effectively drain washing water on the floor, where the water used to wash the flooring flows through the joist member to the sleeper member and is drained from the drain pipe to the outside.
As a result of extensive investigation, the inventors of the present invention have found that the flooring described above still has room to improve, i.e., that the thickness of the flooring should be thinned further as a whole and that the workability should be improved even more.
SUMMARY OF THE INVENTION
The present invention has been made in view of the above, and an object of the present invention is therefore to provide washable flooring for a building which can readily be constructed with a simple work.
The gist of the present invention is as follows.
According to the present invention, in flooring for a building which has a plurality of floor panels laid in parallel to constitute a whole floor, an opening is formed on a floor surface between one floor panel and its adjacent floor panel. The flooring for a building according to the present invention is provided with a gutter portion that is arranged below the opening to receive a liquid dripping from the opening. The gutter portion is formed as an integral part of the one floor panel, and communicates with a drain pipe for draining the liquid in the gutter portion to the outside.
Each of the floor panels has the gutter portion on one side and, on the other side, a connecting portion for connecting the gutter portion of another floor panel. The floor panels having the same shape are arranged such that the gutter portion of one floor panel is connected to the connecting portion of another floor panel, whereby the plural floor panels paralleled in the lateral direction may constitute the whole floor.
Alternatively, each of the floor panels may be formed into a rectangular shape in plane, and a plurality of sleeper members each having a flow path open to above and supporting the floor panel may be provided beneath the whole floor.
Each of the sleeper members is substantially perpendicular to the gutter portion at a vertical position below the gutter portion, and the gutter portion communicates with the flow path of the sleeper member to flow the liquid in the gutter portion into flow path.
A second opening may be formed on a floor surface between one floor panel and its longitudinally-adjacent floor panel, and one sleeper member may be arranged under this second opening, so that the flow path in the sleeper member directly receives a liquid dripping from the second opening. Note that longitudinally-adjacent floor panels means floor panels adjacent to each other in the direction coaxial with the gutter portion.
Also may be provided between every adjacent floor panels is a catch basin portion that is on the same plane as the surface of the floor panels.
The catch basin portion can take any structure as long as it is capable of bearing the weight of people who step on it and of passing a liquid such as washing water from the surface to the underneath. For example, it may be a catch basin portion having a lot of slits perforated to communicate spaces above and under the floor, or may be a mesh-like catch basin portion. Alternatively, the catch basin portion may be formed of a water-penetrative material.
According to the present invention, it is possible to obtain washable flooring for a building which can readily be constructed with a simple work.
It is also possible to obtain washable flooring for a building whose thickness can be thinned as a whole.
It is also possible to obtain washable flooring for a building which has excellent drain efficiency.
It is also possible to obtain washable flooring for a building whose components are easy to mold.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a perspective view showing a single floor panel of flooring for a building according to one embodiment of the present invention;
FIG. 2 is, a plan view showing the single floor panel according to the embodiment;
FIG. 3 is a frontal view showing the single floor panel according to the embodiment;
FIG. 4 is a side elevational view showing the single floor panel according to the embodiment;
FIG. 5 is a sectional view in which the floor panel cut along the line A-A′ in FIG. 1 is connected to its adjacent floor panel;
FIG. 6 is a sectional view showing the floor panel cut along the line B-B′ in FIG. 1 is placed on a sleeper member;
FIG. 7 is a perspective view showing four floor panels combined in accordance with the embodiment;
FIG. 8 is a perspective view showing the flooring for a building constructed in accordance with the embodiment;
FIG. 9 is a sectional view showing another mode of the sleeper member cut along the line D-D′ in FIG. 10;
FIG. 10 is a sectional view showing the floor panel cut along the line C-C′ in FIG. 9; and
FIG. 11 is a perspective view showing the flooring for a building according to the embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Flooring for a building according to the present invention will be detailed further below with reference to FIGS. 1 to 11 .
In the flooring for a building of this embodiment, a plurality of floor panels 2 are laid in parallel to form a whole floor.
As shown in FIGS. 1 to 4 , each of the floor panels 2 is comprised of: a panel body that is rectangular in plane; a concave gutter portion 30 formed on one of longer sides of the panel body (a first side); and a connecting portion 40 that is formed on the other longer side of the panel body (a second side) and has a shape corresponding to the shape of the external edge of the gutter portion 30 . The gutter portion 30 and the connecting portion 40 are, as shown in FIG. 5, integrated with a main body portion 20 that constitutes a core material of the respective floor panels 2 .
The gutter portion 30 is composed of: a first stepped portion 31 extending downward from the edge of one longer side of the main body portion 20 ; an inner side wall 32 hanging from the first stepped portion 31 ; a bottom portion 33 continued from the inner side portion 32 ; and an outer side wall 34 rising from the outer edge of the bottom portion 33 .
The connecting portion 40 is composed of a second stepped portion 41 extending downward from the edge of the other longer side of the main body portion 20 , and a connecting side wall 42 hanging from the second stepped portion 41 .
On the other hand, both of the shorter sides of the respective floor panels 2 (a third side and a fourth side) have the same configuration. The shorter sides are each composed of: a third stepped portion 21 extending downward from the edge of one shorter side of the respective floor panels 2 ; a first slant portion 23 inclined outward and downward from the third stepped portion 21 , a side wall 22 hanging from the first slant portion 23 ; a second slant portion 24 inclined upward from a lower part of the side wall 22 to the inside of the respective floor panels 2 ; and a hook portion 25 hanging from the edge of the second slant portion 24 .
The first stepped portion 31 , the second stepped portion 41 , and the third stepped portions 21 , 21 are all formed at the same vertical position.
FIGS. 5 and 6 are sectional views taken along the line A-A′ and B-B′, respectively, in FIG. 1 in which the plural floor panels 2 are connected and placed on a plurality of sleeper members 60 , while catch basin portions 80 and 90 are set between every adjacent floor panels 2 . That is, shown in FIG. 1 is a single the floor panel out of the plural floor panels 2 whereas FIGS. 5 and 6 each show the plural floor panels 2 , which are supported by the plural sleeper members 60 .
A cover member 70 that serves as the floor face and has a rectangular shape is placed over the main body portion 20 of the respective floor panels 2 sandwiching therebetween an elastic member 75 molded from silicon rubber or the like. Four sides of the cover member 70 serve as side walls 71 hanging from the floor surface, and cover the elastic member 75 .
A reinforcing portion 27 having a triangular shape in section is provided at the center of the main body portion 20 , in parallel with the side wall 22 . The reinforcing portion 27 is formed by bending the center of the main body portion such that it protrudes downward.
In each of the floor panels 2 with this configuration, a member connecting to the main body portion 20 , which excludes the cover member 70 , is integrated with the main body portion 20 . This may be formed by bending one sheet of metal (such as stainless steel plate), or by welding the two members. Alternatively, the main body portion 20 and the member integrated with the portion 20 may be obtained by filling a mold with a resin or the like.
In order to lay the floor panels 2 , as shown in FIG. 5, the connecting portion 40 of one of the floor panels 2 is fit into the gutter portion 30 of another one of the floor panels 2 adjacent to the former panel. In other words, the height of the outer side wall 34 of the gutter portion 30 is substantially the same as the height of the connecting side wall 42 of the connecting portion 40 , and the top of the outer side wall 34 abut the back of the second stepped portion 41 of the connecting portion 40 . The height of the connecting side wall 42 may be shorter than that of the outer side wall 34 . In this way, the floor panels 2 are connected one after another in the lateral direction.
To lay the floor panels 2 in the longitudinal direction, the floor panels 2 are placed on the plural sleeper members 60 that have previously been installed with given intervals, which correspond to the width in the longitudinal direction of the respective floor panels 2 . That is, as shown in FIG. 6, each of the sleeper members 60 has fixed thereon an end of one of the floor panels 2 and an end of another one of the floor panels 2 adjacent thereto, the ends facing each other.
Each of the sleeper members 60 is formed from a hollow steel material having an opening on its center top, and is composed of a bottom 61 , side walls 62 , 62 standing upright on the bottom 61 , and slant tops 63 , 63 inclined downward from upper portions of the side walls 62 , 62 . The slant tops 63 , 63 have the same inclination as that of the second slant portion 24 . The width on the back side of the second slant portion 24 and the width on the upper side of each slant top 63 are substantially the same. Therefore, the shorter sides of the respective floor panels 2 in FIG. 6 are positioned to the left and to the right of the upper portion of each of the sleeper members 60 , respectively, and are fixed thereon.
A bolt 12 pierces through the first slant portion 23 and the second slant portion 24 of the respective floor panels 2 , and the slant top 63 of the respective sleep members 60 to thereby firmly fix the respective floor panels 2 to the respective sleep members 60 . The first slant portion 23 , the second slant portion 24 , and the slant top 63 which are fixed by the same bolt 12 are inclined in the same direction, making it easy to set or remove the bolt 12 .
Now, FIG. 7 shows four floor panels 2 combined together. The catch basin portion is arranged between every adjacent floor panels 2 . In other words, the catch basin portion 80 is set in a first opening (previously mentioned as opening) 16 above the gutter portion 30 while the catch basin portion 90 is set in a second opening (previously mentioned as second opening) 14 above and perpendicular to the gutter portion 30 .
The catch basin portions 80 and 90 are, as shown in FIGS. 5 and 6, each provided with a top plate portion 81 and leg portions 82 , 82 that are formed on both widthwise edges of the top plate portion 81 . The center of the top plate portion 81 has on its back side a conduit tube 84 inside which a channel 85 is formed. The channel 85 communicates with a pair of sprinkling holes 86 , 86 extending straight from the upper portion of the conduit tube 84 to the surface of the top plate portion 81 . Multiple pairs of sprinkling holes 86 , 86 are formed axially with respect to the catch basin portions 80 and 90 . Each pair of sprinkling holes 86 , 86 are formed outward (toward the floor panels 2 ) at an angle of roughly 45° C. with respect to the horizontal direction. The front sides of the catch basin portions 80 and 90 communicate with the first opening 16 and the second opening 14 , which are below the catch basin portions 80 and 90 , respectively, through a large number of communication holes (not shown).
Upon construction of the flooring for a building according to this embodiment, as shown in FIG. 8, a plurality of sleeper members 60 are arranged in parallel in accordance with the width of the respective floor panels 2 . Each of the sleeper members 60 is supported by a strut member 6 on a floor slab 3 . An adjuster 7 is provided on the bottom of the strut member 6 , making it possible to adjust the height of the strut member. In FIG. 8, sleeper members 60 A and 60 B each illustrate a complete sleep member, and a floor panel 2 b represents a complete floor panel. However, in order to facilitate understanding of the flooring structure, some of the sleeping members and a part of the flooring panel are cut off in FIG. 8 .
One of the floor panels 2 is placed flush against a wall 5 , striding over two adjacent sleeper members 60 , and then the floor panels 2 are laid one after another in a single file in the longitudinal direction. Each of the floor panels 2 is fixed to the sleeper members 60 by the bolt 12 . Continuous laying of the floor panels 2 in the lateral direction (the axial direction of the sleep members 60 ) is achieved by repeating connecting the gutter portion 30 of one of the floor panels 2 to the connecting portion 40 of another one of the floor panels 2 laterally-adjacent thereto (corresponding to the relation between the floor panel 2 b and a floor panel 2 a ) and then fixing both the floor panels 2 with the bolts 12 , 12 . Positioning of the floor panels 2 can be accurately made through a simple work where all that is required is to fit the connecting portion 40 of the floor panel to be laid next into the gutter portion 30 of the already installed floor panel.
A horizontal drain pipe 8 is provided near one ends of the assembled sleep members 60 such that the pipe is perpendicular to the sleep member. The horizontal drain pipe 8 communicates with the inside (flow path) 64 of the respective sleep members 60 through a vertical drain pipe 9 . A sealing portion 88 is attached to the gutter portion 30 on every edge of the whole floor. A shield 15 is applied to the vicinity of each boundary between the floor and the wall 5 so that the splashed washing water does not soil the wall 5 .
Next, the operation in washing the flooring will be described.
When a caretaker operates a not-shown control panel, a feed valve connected to the terminal of the conduit tube 84 is opened to feed washing water into the channel 85 . The washing water in the channel 85 is sprinkled from the sprinkling holes 86 , 86 on the top of the floor panels 2 (the surface of the cover member 70 )
The washing water used to wash the top of the floor panels 2 drips downward through the communication holes formed in the catch basin portions 80 and 90 , or through gaps between the catch basin portions 80 and 90 and the floor panels 2 , respectively. The washing water dripping from the catch basin portion 80 is received by the gutter portion 30 , and runs through the gutter portion 30 and the terminal thereof down to one of the sleep members 60 . The washing water dripping from the catch basin portion 90 is directly received by one of the sleep members 60 . Then, the washing water in the respective sleep members 60 flows into the horizontal drain pipe 8 through the vertical drain pipe 9 , and is drained into a major drain pipe.
The description given next deals with a repairing process in case of breakage of the flooring, or on other similar occasions.
The damage most often given to the floor panels 2 after the completion of construction is superficial damage. In that case, repair is done by simply replacing the cover member 70 . If the entire removal of the floor panels are need, since each of the floor panels 2 can readily be replaced, repair is easily carried out as follows: the floor panels 2 are removed in order starting from the one situated on the extreme end in the direction of the gutter portion 30 , panels that need repairs are replaced with new floor panels 2 , and then undamaged panels among the removed floor panels 2 are returned one after another.
As described above, according to the flooring for a building of this embodiment, the need for a conventional joist member is eliminated and the thickness of the flooring as a whole can be thinned accordingly.
The gutter portion 30 and the connecting portion 40 are integrated with the respective floor panels 2 , making it possible to reduce the number of parts as well as to simplify the operation of connecting the floor panels. Moreover, the gutter portion 30 of the respective floor panels 2 can establish communication between its terminal and the opening of the respective sleeper members 60 while simply being suspended over the sleeper members 60 , promoting an easy construction.
The structure of and around the sleeper member may be as shown in FIGS. 9 to 11 . To elaborate, the sleeper member may be composed of separate members, one of which is a member for receiving the load of the floor panel and the other of which serves as a drainage path.
A pair of support members 162 , 162 formed from hollow beams (steel) to support a floor panel 102 are integrated with a bottom plate 161 by welding. An upper support member 163 is provided between the floor panel 102 and the supporting member 162 . The upper support member 163 is bent downward at its ends, forming stepped portions 163 a , 163 a . A cover portion 170 of the floor panel 102 is also bent downward to form, above the stepped portion 163 a , a stepped portion 170 a that has the same shape as the stepped portion 163 a .
The upper support member 163 and the supporting member 162 are fixed to each other with a bolt 113 . The upper support member 163 (the stepped portion 163 a ) is fixed to the cover member 170 (the stepped portion 170 a ) using a bolt 112 .
An alcove 169 is formed between the supporting member 162 and the stepped portion 163 a .
Above the bottom plate 161 , a semicylindrical drainage path portion 165 made of polyethylene is arranged with a mortar layer 167 therebetween. Upper ends 165 a , 165 a of this drainage path portion 165 are swelled out, maintaining their elasticity, and are fitted into the alcoves 169 , 169 .
In the drainage path portion 165 , a flow path 164 directly receives waste water dripping from the catch basin portion 90 between adjacent two floor panels 102 , 102 .
In a sleeper member 160 , the drainage path is formed from a synthetic resin member. The drainage path portion 165 is thus formed separately from members for receiving the load ( 162 and other members), which require a solid structure. This makes unnecessary the use of an expensive material such as stainless steel for the sleeper member 160 , reducing the cost of constructing the flooring on the whole. Moreover, it is easy to replace only the drainage path portion 165 , which has more chances to be soiled than other parts of the sleeper member 160 .
The present invention is not limited to the contents of the embodiment described above, but is adaptable to various modifications by those skilled in the art without departing from the spirit of the present invention defined by the scope of patent claims attached hereto. | To provide flooring for a building, more specifically, flooring washable at its installation place in a building. In the flooring for a building which has a plurality of floor panels laid in parallel to constitute a whole floor, an opening is formed on a floor surface between one floor panel and its adjacent floor panel. The flooring for a building according to the present invention is provided with a gutter portion that is arranged below the opening to receive a liquid dripping from the opening. The gutter portion is formed as an integral part of the one floor panel, and communicates with a drain pipe for draining the liquid in the gutter portion to the outside. The present invention thus provides washable flooring for a building which is easy to construct. | 4 |
BACKGROUND
[0001] a. Field of the Invention
[0002] The present invention relates to the monitoring of underwater mooring lines, for example heavy duty anchoring chains or steel rope lines. In particular, this invention relates to monitoring the tension and/or the inclination in underwater mooring lines, for example as used in the offshore oil and gas industry.
[0003] b. Related Art
[0004] Mooring components may be used in several applications, for example in the long-term mooring of floating production systems or mooring of mobile offshore units.
[0005] The mooring lines used in these situations are generally of a significant length, and may need to bear loads of many hundreds, or even thousands, of tonnes. The mooring lines may be formed from chain links or fiber material, for example steel rope.
[0006] There is often the need to measure direct in-line tension and inclination of a mooring line. One known way of doing this is to use an instrumented load shackle connected to the mooring line. A number of problems have been noted with the use of instrumented load shackles. The sensor instruments are normally housed within the removable steel pin of the shackle, with electrical power and signaling lines running in one or more cables alongside the mooring line and extending to monitoring equipment at the surface. A connecter at the end of the removable shackle pin must be used to connect the cables to the sensors within the shackle pin. The connectors and cables are exposed and vulnerable to handling damage either when the mooring line is set in place or at a later time when work is done around the mooring line.
[0007] Cables running down a mooring line tend to fail prematurely. This is because the mooring system is very dynamic. It is hard to restrain a cable to the mooring line without the cable being too loose, which can cause a loop to form in the cable. Slack in the cable results in fatigue where the cable breaks the surface, either due to surface currents or waves. On the other hand, if the cable is too tight, the cable will either snap or be pulled out from cable connectors. There is typically no easy way for a cable to leave the mooring line and join the vessel or platform. The cable either has to have long lengths unsupported in the splash zone, and often a cable may have to run over sharp edges or be routed in fare leads. The installation and recovery of a mooring line monitoring system that uses cables is a long and tricky job, and this is compounded when there is bad weather or when it is necessary to work on the back of an anchor handler deck.
[0008] A load shackle also provides only an indirect measurement, and so the accuracy of the instrumented shackle is directly related to chain position on the shackle's spool piece. Over the life of the mooring installation, the end link of the chain may move away from the centre of the spool which can lead to very inaccurate results.
[0009] An estimate of mooring line tension may be gained from calculations when the mooring line forms a known catenary shape, but this is typically only possible on permanent installations. This technique requires detailed knowledge of the geometry of the installation. Such calculations also need to include assumptions on the mooring line materials and do not take into account manufacturing tolerances. The catenary shape of the mooring line is also likely to change over its life due to creep or decay.
[0010] In addition, large mooring systems require life spans of up to 30 years in a permanent position and, therefore, any connectors must withstand the harsh offshore environment.
SUMMARY OF THE INVENTION
[0011] It is an object of the present invention to address the problems cited above, and provide an improved mooring line monitor for monitoring at least one operational condition of an underwater mooring line.
[0012] Accordingly, the invention provides a mooring line monitor for monitoring at least one operational condition of an underwater mooring line, the mooring line monitor comprising an elongate main body, a protective shroud, at least one operational condition sensor for monitoring the, or each, operational condition, at least one acoustic transmitter, and a source of electrical power for powering the operation of the, or each, sensor and the, or each, transmitter. The main body has at opposite first and second ends, respectively, a first mooring line connection and a second mooring line connection and between these connections an intermediate portion of the main body. The first mooring line connection is configured for connection to a first underwater mooring line and the second mooring line connection is configured for connection to a second underwater mooring line such that, in use, the intermediate section is under tension between these first and second ends when the mooring line is under load. The, or each, operational condition sensor is attached to the intermediate section. The sensor has a signal output for providing a signal regarding the sensed operational condition. The acoustic transmitter has a signal input, and the signal output is connected to this signal input so that, in use, the output signal is received by the input. In general, the acoustic transmitter will have an acoustic output for transmitting information regarding the received signal through water surrounding the mooring line monitor when underwater.
[0013] It is then possible to monitor operational conditions of the mooring line in situ, and transmit data concerning the monitored conditions through the water, for example to a nearby ship or offshore platform. The conditions monitored may be any pertinent operation conditions, for example, mooring line tension, inclination or movement.
[0014] Because the sensor is provided in the mooring line, in particular the intermediate portion of the main body, the mooring line monitor becomes an integral part of the mooring line and is subject to the same conditions as the rest of the line. Because mooring line tension is transmitted directly through the intermediate portion, a direct inclination or tension measurement may be made on the intermediate portion, for example using an inclination sensor, or a strain sensor attached directly to the intermediate portion of the main body.
[0015] Acoustic communication does away with the need for exposed cables on the mooring line, which also simplifies deployment and recovery of the mooring line monitor. This greatly improves the ease of installation and recovery and results in greater overall system reliability.
[0016] The mooring line monitor can also be used in place of a conventional mooring line linkage, when it is necessary to join together two length of mooring line.
[0017] In a first aspect of the invention, the protective shroud extends around the intermediate portion of the main body in order to encompass and protect the, or each, sensor, transmitter and source of electrical power.
[0018] In a second aspect of the invention, the acoustic transmitter is elongate and the protective shroud extends annularly around the intermediate portion of the main body in order to protect the, or each, sensor, the elongate transmitter(s) being provided within the shroud and being aligned substantially parallel with the axis of the elongate main body.
[0019] In a third aspect of the invention the mooring line monitor comprises an elongate and substantially cylindrical main body and the opposite first and second ends of the main body define an axis of the cylindrical main body. The acoustic transmitter has an acoustic output for transmitting information through surrounding water regarding the received signal. The protective shroud is a substantially annular covering that wraps around the intermediate portion of the cylindrical main body in order to encompass and protect the, or each, sensor. The shroud has an aperture therein and the transmitter is embedded with the protective shroud with the acoustic output being exposed in this aperture
[0020] To enable the mooring line monitor to pass smoothly over rollers or pulleys, for example, without getting caught or derailing the mooring line, ideally the shroud has tapered ends which may include a smooth transition with end portions of the main body. These end portions are then preferably rounded. Most preferably, if a transmitting portion of the transmitter needs to be exposed to the surrounding water, then such a portion may extend through an aperture in the main body. The transmitting portion of the transmitter may then be seated in a recess in the external surface of the shroud , the recess being surrounded by a lip or edge which, in use, protects the transmitter from damaging contact, for example with pulleys or rollers over which the mooring line passes when being played out or taken in. In a preferred embodiment of the invention, this recess is provided in a tapering section of the shroud proximate the end of the main body.
[0021] Acoustically transmitted data from the monitor is received at the surface, for example at a drilling rig, by means of a receiving acoustic modem. Top side equipment can then be used to record and display the recovered data concerning one or more operating conditions of the mooring line.
[0022] Although it will often be the case that the mooring line monitor will be used to join together two similar types of mooring line, for example steel link chains, the first and second linkages may be adapted for use with different type of mooring line, for example with the linkage at one end of the main body being adapted for joining to a steel chain mooring line and the linkage at the other end of the mooring line monitor being adapted for joining to a steel rope mooring line.
[0023] A preferred embodiment of the invention will now be further described, by way of example only, and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIG. 1 is a perspective view of a mooring line monitor according to a preferred embodiment of the invention, the monitor being used to join together two lengths of steel chin links;
[0025] FIG. 2 is an exploded view of the mooring line monitor of FIG. 1 , showing how this comprises a central main body, to which a pair of operational condition sensors have been attached, the sensors each being wired to one of a pair of acoustic transmitters on opposite sides of the main body that are protectively housed within a two-piece outer shroud;
[0026] FIG. 3 is a plan view of a part of the mooring line monitor, taken along lines III-III of FIG. 2 ;
[0027] FIG. 4 is a plan view from the side of a part of the mooring line monitor, taken along line IV-IV of FIG. 3 ;
[0028] FIG. 5 is a view similar to that of FIG. 3 , but with the protective shroud removed so that the position of one of two operational condition sensors on opposite sides of the main body can be fully seen, each sensor being connected by means of a data and power cable to a corresponding one of the pair of acoustic transmitters;
[0029] FIG. 6 is an enlarged plan view of the location one of the operational condition sensors on the main body, as indicated by the dashed circle labeled VI in FIG. 5 ;
[0030] FIG. 7 is a cross-section through the pair of operational condition sensors, the main body and connecting cable, taken along line VII-VII of FIG. 6 ;
[0031] FIG. 8 is a view of the main body at right angles to that of FIG. 5 ;
[0032] FIG. 9 is an enlarged plan view of the location of the position of one of a pair of locating recesses in the main body used to locate and secure the outer shroud, as indicated by the dashed circle labeled IX in FIG. 8 ;
[0033] FIG. 10 is a cross-section through the recess of and main body, taken along line X-X of FIG. 9 ;
[0034] FIG. 11 is a perspective view of the mooring line monitor of FIG. 1 , less one shroud half, showing the position of one of the locating recesses with respect to a corresponding acoustic transmitter module and connecting cable;
[0035] FIGS. 12 and 13 are perspective and plan views showing the inside surfaces of one of the shroud halves, which provide a seating surface for the main body; and
[0036] FIGS. 14 and 15 are opposite end views of the shroud half, taken respectively along lines XIV-XIV and XV-XV of FIG. 13 .
DETAILED DESCRIPTION
[0037] FIG. 1 shows a mooring line monitor 1 of a preferred embodiment of the invention for use in long term mooring applications. In use, the mooring line monitor 1 will form a joining link within a mooring line below the water line, for example when mooring floating production systems or mooring of mobile offshore units. The monitor will typically be installed at a natural join within a mooring line. Although FIG. 1 shows in dashed outline the ends of two lengths of steel chain links, 2 , 4 , either or both ends of the mooring line monitor 1 may equally well be connected to other types of mooring line, for example fiber tether. The mooring line monitor may therefore be used either to link two lengths of similar lines, or be used to connect two dissimilar mooring lines, for example chain link and steel rope.
[0038] The mooring line monitor 1 comprises an elongate main body 10 and two pin assemblies one of which 6 is visible in the drawings. Each pin assembly is removable from the main body so that the end of a mooring line, for example chain links 2 , 4 , may be connected to and disconnected from the mooring line monitor 1 .
[0039] As shown in FIGS. 2 to 4 , the elongate main body 10 is substantially cylindrical and has a first end portion 8 and a second end portion 9 . In this example, each end portion 8 , 9 provides a slot 12 inside of which the pin assembly 6 is seated. The slot has a base 13 and the pin assembly is held by a pair of bores 7 through which the pin assembly 6 passes. The bores are provided in side portions 14 of the slot 12 that extend away from a base 13 of the slot, so that the side portions form opposite sides of the slot.
[0040] Typically, the elongate main body 10 will have a length of between 0.8 m and 2.0 m and a width, or diameter, of between 0.3 m and 0.4 m, and will have main components machined from forged steel of a similar composition or grade to that used in the chain links 2 , 4 . In this example, the main body 10 is about 1.6 m long and 360 mm in diameter, and is rated to bear loads of up to about to 480 tonnes.
[0041] Each slot 12 is formed in one of the ends 8 , 9 of the elongate main body 10 so that each slot is open towards the respective end of the main body. The slots each define the corresponding side portions 14 on either side of the slot. In this example, the side portions have outer surfaces in the form of rounded cheeks 15 and flat opposing inner surfaces 16 . In a preferred embodiment, the width of the slot 12 at its base 13 is slightly narrower than the width of the slot at the end-most surface 17 of the main body 10 . In this way, the distance between the opposing inner surfaces 16 decreases towards the base 13 of the slot 12 . This is shown most clearly in FIG. 4 .
[0042] The pin assembly 6 may be fixed to the bores 7 in a number of different ways, as will be apparent to those skilled in the art. The exact from of the pin assembly is not critical to the functioning of the present invention. It is preferred, however, if the pin assembly is of the type described in patent document GB 2480060 A, in the name of one of the present inventors. The entire contents of GB 2480060 A are hereby incorporated herein by reference.
[0043] As shown most clearly in FIG. 8 of GB 2480060 A, the shank of the pin assembly 6 does not have a circular cross-section, but has a cross-sectional shape that is approximately pear-shaped. The importance of the non-circular cross-section will be described in more detail later.
[0044] Returning to FIG. 4 , when the pin assemblies 6 are fully assembled in the main body 10 , the ends of the pin assemblies are held fully within the bores 7 and therefore within the outer bounds of the main body 10 . This provides protection to the pin assemblies. Preferably the outermost ends of the pin assemblies 6 are recessed, although these may be flush with the outer surface of the main body 10 . This, together with the substantially rounded cross-section of the cheeks 15 and endmost surface 17 of the main body ends 8 , 9 , permits the main body 10 to move freely over rollers as the connected chains are installed or recovered.
[0045] In use, the pin assemblies 6 may be removed from the main body 10 , in order to connect or disconnect the ends of the adjacent mooring lines, 2 , 4 . An end link of a first chain 2 is then positioned in one of the two slots 12 at an end 8 , 9 of the main body 10 . As explained in GB 2480060 A, a retaining pin is then inserted so that the shaft of the pin passes through one bore 7 and through the eye of the chain link 2 and through the opposite bore 7 . Once inserted, the pin assembly 6 is secured as described in GB 2480060 A.
[0046] Typically, the shapes of the links of chains used in mooring applications are not perfectly oval or circular. The eye of a link generally narrows towards each end of the link. The non-circular shape of the shaft of the retaining pin is, therefore, designed to engage with the shape of the eye, with the narrower part of the pear-shaped cross-section engaging with the end portion of the link.
[0047] Shaping the retaining pin in this way has the advantage that the retaining pin is less likely to rotate within the eye of the chain link once connected. As the chains are moved there is a tendency for the associated retaining pins to rotate within the bores of the main body 10 rather than the pins rotating with respect to the links 2 , 4 . This decreases the wear, thereby increasing the useful life of the monitor 1 .
[0048] FIGS. 2 to 15 show in detail the other components of the mooring line monitor 1 . The main body 10 has, between the first and second end portions 8 , 9 , an intermediate portion or section 18 . Because the intermediate portion is between the ends, and is formed from the same block of steel as the end portions, the intermediate section 18 is under tension between the first and second ends 8 , 9 when the mooring line 2 , 4 is under load.
[0049] The intermediate section 18 is nearly cylindrical, apart from four approximately rectangular pockets or recesses 31 - 34 spaced equidistantly about a mid-plane or equator of the main body 10 . Two of the recesses 31 , 33 , on opposite sides of the main body, are sensor recesses used to house an operational condition sensor 35 , 36 , each of which is protected within its recess by a removable cover plate 37 which provides a hermetic seal against water ingress.
[0050] As will be explained in more detail below with reference to FIGS. 8 to 10 , the other two recesses 32 , 34 , also on opposite sides of the main body, are locating recesses that provide a location feature for locating and securing the position of each shroud half 21 , 22 to the main body.
[0051] The invention is applicable to different types of sensors. In this example, each sensor 35 , 36 comprises a set of strain gauges, which are bonded into the floor 38 of each recess. The strain gauges 35 , 36 are situated directly opposite each other at the midpoint of the intermediate portion 18 of the main body 10 . Each strain gauge 35 , 36 includes a circuit board with electronic circuitry and an electrical output 39 . The circuitry provides a conditioned output signal at the signal output that will include data, either analog or digital, regarding the sensed operational condition, which in this case is strain within the intermediate portion of the main body.
[0052] The output therefore provides a stable signal which is then transmitted via a connecting cable 41 to an acoustic transmitter module 48 , 49 . Each connecting cable is joined at one end to its operational condition sensor 35 , 36 at a water-tight connector 42 on the cover plate 37 , and at the other end to the transmitter module.
[0053] Each transmitter module 48 , 49 includes electronic circuitry, including a data logger (not shown). Received data is transmitted acoustically to the surface at an acoustic output 50 of the module. Although not illustrated, also provided within the transmitter module is a lithium ion battery power source, for powering the sensor electronics, the data logger and the acoustic transmitter. The acoustic transmitter 50 is provided at one end of the module, which has a substantially cylindrical elongate form.
[0054] It is preferred that the operational condition sensors 35 , 36 also include an inclinometer, so that inclination data is also transmitted to the data logger via the cable. This gives the angle of the mooring line. Although not shown in detail, the strain gauges are wired in a full bridge, two of the strain gauges being located on either side of the intermediate portion 18 to complete the bridge, so that any undesired bending of the intermediate portion can be detected and accounted for in a calculation of the load transmitted by the main body 10 between the mooring lines 2 , 4 .
[0055] The operational condition sensors may also include an accelerometer or other type of movement sensor.
[0056] The intermediate portion 18 also includes two channels in the form of cylindrical bores 54 , 55 joining each sensor recess 31 , 33 so that, if needed, the sensor electronics or the acoustic transmitter modules may be linked by one or more electrical cables.
[0057] A protective shroud 20 is used to protect the operational condition sensors, transmitter modules 48 , 49 and connecting cables 41 . The shroud is preferably formed predominantly from a polymer material, for example a tough polyurethane, polypropylene or nylon material. The shroud 20 extends around the intermediate portion 18 of the main body 10 in order to encompass and protect the sensors 35 , 36 , the acoustic transmitters 50 and the source of electrical power and other electronics provided within the acoustic transmitter module 48 , 49 . The shroud is hollow and has a substantially annular mid-portion 11 and a pair of substantially frustoconical end portions 28 , 29 either side of the mid-portion.
[0058] The shroud is formed in two halves 21 22 which when joined together by fixing means, for example connecting bolts 23 nuts 24 , wraps around the intermediate portion 18 of the main body 10 . In this example, the fixing means are six sets of bolts 23 and nuts 24 , three on each side of the assembled shroud 20 . Each bolt 23 passes through one of three aligned bores 53 , 63 in each shroud half 21 , 22 . Both of these bores have an internal shoulder (not shown) on which rests either a head 59 of the bolt or the nut 24 .
[0059] The shroud halves 21 , 22 are joined together along a mid-plane of the shroud 20 extending parallel with an axis 19 of the main body 10 . Each half of the shroud has an axially extending elongate socket 40 in which each transmitter module 48 , 49 is seated. The socket 40 extends fully through the shroud, being open at both ends, and provides a cylindrically shaped surface 51 which engages around the full circumference of the transmitter module 48 , 49 . When being assembled with the shroud halves 21 , 22 , each transmitter module is inserted axially into the socket to make a tight sliding fit with this surface 51 . Each transmitter module has, at the non-transmitting end, an annular mounting plate 62 which is bolted 71 to a corresponding annular mounting surface 72 . The seated transmitting modules are therefore aligned parallel with the main body axis 19 . The shroud 20 may be disassembled by releasing the fixing means 23 , 24 to gain access to the transmitter module, cables 41 and/or the sensors 35 , 36 .
[0060] As shown in FIG. 2 , when a shroud half 21 , 22 and its seated transmitter module 48 , 49 are to be secured to the main body, an inner surface 30 of the shroud half 21 , 22 is brought to bear against a corresponding cylindrical outer surface 43 of the main body intermediate portion 18 . The shroud inner surface 30 is a cylindrical surface which matches that of the intermediate portion. A locating projection 52 extends radially inwards from the shroud cylindrical inner surface 30 . This projection is shaped to engage within one of the empty locating recesses 32 , 34 . The shroud inner surface 30 and projection 52 therefore locate the shroud in both a circumferential direction and a longitudinal direction once the shroud halves are joined together.
[0061] Each end of the sockets 40 terminates in an aperture 25 , 26 , one of which 25 will, in use, be oriented generally upwards, and the other of which 26 will, in use, be oriented generally downwards. The upper aperture 25 is at the transmitting end 50 of the acoustic transmitter module 48 , 49 and has a generally conical inner surface 27 , which forms a protective recess around the acoustic transmitter 50 . The lower socket 26 at the other end of the transmitting module has a generally cylindrical form. In use, the acoustic transmitter modules 48 , 49 are oriented with the acoustic transmitter 50 seated inside the upper apertures 25 , recessed within the conical surface 27 , and pointing upwards in the water, so that acoustic signals transmitted by the acoustic transmitter module are received by a receiving acoustic modem at the surface. The upper apertures 25 therefore facilitate the transmission of information while at the same time protecting the acoustic output 50 .
[0062] The acoustic transmitter 50 is sufficiently recessed inside the upper aperture 25 so that the transmitting end of the transmitter module is fully protected by the surrounding frustoconical upper end portion 28 of the shroud. The mounting surface 72 to which the acoustic module mounting plate 62 is bolted is provided inside the lower aperture 26 . The mounting plate is sufficiently recessed inside the lower aperture 26 so that the mounted end of the transmitter module is fully protected by the surrounding frustoconical lower end portion 29 of the shroud.
[0063] Each of the upper and lower end portions 28 , 29 terminates in shoulder 3 , 3 ′ that extends at right angles to the main body axis 19 and which is substantially annular, being broken by the pair of conical recesses or apertures 25 , 26 . The shroud therefore has an outer surface that is tapered towards the cylindrical main body towards the first and second end portions 8 , 9 . In this example, each of the tapered portions 28 , 29 of the shroud is substantially frustoconical, with an intermediate portion 11 that is substantially cylindrical.
[0064] As shown most clearly in FIGS. 4 and 11 to 13 , the each shoulder 3 , 3 ′ of the shroud has an inwardly directed lip 5 , 5 ′ having a generally cylindrical inner surface 65 , 65 ′ that makes contact with the cylindrical outer surface of the main body 10 in the region where the main body intermediate portion 18 borders on the adjacent end portions 8 , 9 . As shown in detail in FIGS. 12 to 15 , the cylindrical inner surface 30 of the shroud is provided on a plateau-like central raised region 56 within the shroud, of generally rectangular outline, and is surrounded on four sides by a channel 60 to allow for clearance of the sensor cover plates 37 , each of which stands proud of the cylindrical outer surface 43 of the intermediate portion 18 of the main body 10 , and also allows space for passage of the cable 41 between each sensor 35 . 36 and its associated transmitter module 48 , 49 . The channel 60 extends on a first pair of opposite sides 57 , 58 of the raised region 56 between the cylindrical inner surface 30 and each radially inwardly directed lip 5 , 5 ′ of the shroud shoulders 3 , 3 ′. The channel 60 also extends on a second pair of opposite sides 67 , 68 of the raised region 56 between the cylindrical inner surfaces 30 of both shroud halves when these are connected together.
[0065] To relieve stress the junction 61 , 61 ′ between each shoulder 3 , 3 ′ and the corresponding contacting inner surface 65 , 65 ′ of the shroud is chamfered.
[0066] The shroud 20 is durable and tough and passes without damage over spools and rollers during installation or retrieval of a mooring line, while providing at all times protection to the other sensing and acoustic transmission components of the mooring line monitor. At the same time, the shroud keeps the acoustic transmitters aligned correctly for acoustic transmission of data to the surface.
[0067] By incorporating a mooring line connector as described in GB 2480060 A, the mooring line monitor 1 according to the invention avoids problems that may be associated with other types of chain connectors that are known in the art such as Kenter shackles, Pear links and C-type connectors. The choice of mooring line connector solution will often be driven by the method of installation and the handling requirements arising from the particular application. Of particular relevance for long term mooring is the H-link. However, the H-link has several disadvantages in many mooring situations. Firstly the H-link typically comprises a body having a rigid and generally rectangular cuboid shape and as such it is unable to pass easily over line handling rollers and pulleys. Furthermore, the means for connecting ends of mooring lines to the H-link are typically bulky and further restrict the handling of the connected lines. The tapered shroud and main body of the preferred embodiment of the invention avoid these problems, and so are particularly well-suited to long-term mooring situations.
[0068] The invention described above can readily be implemented in typical mooring situations in the offshore oil and gas industry. The mooring lines used in these situations are generally of a significant length, and are typically too long to be produced or handled in one single length. Therefore, typically lengths of chain or steel rope have to be joined together during the off shore installation process. The mooring line monitor described above can therefore conveniently be used in place of a conventional mooring line link used to join such sections of chain or fiber/steel rope together.
[0069] The invention therefore provides a convenient and economical way of monitoring the operation conditions of an underwater mooring line.
[0070] It is to be recognized that various alterations, modifications, and/or additions may be introduced into the constructions and arrangements of parts described above without departing from the spirit or scope of the present invention, as defined by the appended claims. | In some aspects of the inventive subject matter, there is provided a monitor for monitoring at least one operational condition of an underwater mooring line, the monitor comprising an elongate main body, a protective shroud, at least one operational condition sensor for monitoring the, or each, operational condition, at least one acoustic transmitter, and (in some instances) a source of electrical power for powering the operation of the sensor and transmitter. The main body has at first and second ends respectively first and second mooring line connections (each configured for connection to a respective mooring line) and an intermediate portion. In use, the intermediate section is under tension between the first and second ends when the mooring line is under load. The, or each, operational condition sensor is attached to the intermediate section, the sensor having a signal output for providing a signal regarding the sensed operational condition. | 6 |
TECHNICAL FIELD
The present invention relates to containers. More particularly, the present invention relates to containers for fluids having seals for closing the container to the flow of fluids from the containers.
BACKGROUND OF THE INVENTION
Containers are well-known bodies adapted for holding fluids. Typically, fluid-holding containers are open-ended bodies, and may be closable or not. For example, glassware commonly comprises a tubular body with a bottom and defining side walls and an open end for the fluid to pass into and out of the body. Other containers for fluids are closable. Often these containers define a thread on an exterior surface near the open end. A closure device, such as a cap or top, includes a mating thread on an interior face. The cap threads onto the open end to close the container. The cap typically is selectively removed to provide access to the container, and replaced to reclose the container.
Some containers hold products that must be sealed from the atmosphere until use. Often these containers have inner membranes applied across the open end to seal the contents. The inner membrane is unsealed after removing the cap to provide access to the contents.
Bottles holding drinking fluids, such as soft drinks, water, and milk for babies, are often re-sealed for subsequent use of the contents. Baby bottles typically are elongate tubes with a threaded open end and graduations marked on the side wall of the bottle. A resilient nipple having exit holes in a distal end is received on the open end. An annular cap with a threaded skirt couples the nipple to the bottle. Other containers suited for drinking materials include a ported spout that selectively opens. One such spout is pulled to move the spout relative to a longitudinal axis of the bottle and thereby open and close the bottle.
Babies may not completely drink the contents of the bottle, and parents often want to re-close the bottle to save the contents for a subsequent feeding. Some baby bottles include a disk-shaped lid that closes the annular opening in the cap and seals the open end of the nipple, which is typically inverted and disposed inwardly of the bottle. However, this necessitates handling of the nipple and opening the bottle to atmosphere. Similarly, containers for sports and other types of beverages are often partially consumed, with the remaining contents retained for subsequent drinking.
Accordingly, there is a need in the art for and improved container for fluids which is unsealed for use and readily resealed for subsequent use of the remaining contents. It is to such that the present invention is directed.
SUMMARY OF THE PRESENT INVENTION
The present invention meets the need in the art by providing containers for fluids with a selectively actuated seal for closing the flow of fluids from the containers. The container comprises a receiving body for holding a fluid and having an open end. A collar that engages the open end of the receiving body includes a dispensing member attached to the collar for communicating fluids from the receiving body. A sealing membrane disposed between the collar and the open end of the receiving body selectively seals fluid flow from the receiving body. The sealing membrane moves selectively more than once from a sealing position with a sealing surface of the sealing membrane in bearing contact with an edge surface of the open end to a dispensing position with the sealing surface spaced apart from the open end for fluid flow, in response to movement of an actuator.
In another aspect, the container comprises a receiving body for holding a fluid and having an open end with an external thread. A rotatable collar having an internal thread engages the thread on the open end of the receiving body. The interior of the collar defines a shoulder adjacent an extent of the thread. A dispensing member attaches to the collar for communicating fluids from the receiving body. A sealing membrane is disposed between the dispensing member and the open end, with at least one port in a perimeter portion for communicating fluid therethrough. The sealing membrane moves from a sealing position with a sealing surface of the membrane in bearing contact with an edge surface of the open end and a dispensing position with the sealing surface spaced apart from the open end for fluid flow. The sealing membrane moves in response to rotating the collar to move the collar longitudinally outwardly relative to the end by the camming action of the thread on the container. The shoulder breaks the seal between the sealing membrane and the edge of the container.
Further objects, features, and advantages of the present invention will become apparent from a reading of the following specification, in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is cut-away sectional view of a baby bottle having a sealing apparatus according to the present invention.
FIG. 2 is an upper perspective view of a sealing membrane in accordance with the present invention used in the baby bottle illustrated in FIG. 1 .
FIG. 3 is a cut-away sectional view of the baby bottle illustrated in FIG. 1 showing the sealing membrane in the dispensing position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now in more detail to the drawings, in which like numerals indicate like parts throughout the several views, FIG. 1 illustrates in cut-away sectional view a baby bottle 10 having a sealing apparatus generally 12 according to the present invention. The sealing apparatus 12 includes a sealing membrane 14 received on an open end 15 of the bottle 10 . The bottle 10 includes a side wall 18 with an exterior thread 16 in a portion near the open end. The side wall 18 extends to a closed end (not illustrated) for holding a fluid within the bottle 10 .
The open end 15 receives the sealing membrane 14 and a nipple 20 . The nipple 20 is conventional with a protruding extension 22 and laterally extending flange 23 . A distal end of the extension 22 defines an aperture for communicating fluids. A sealing surface 24 of the sealing membrane 14 is disposed for contacting an edge of the side wall 18 defining the open end 15 . An annular clamp ring 26 defines an opening through which the nipple 20 extends. The clamp ring 26 includes a depending skirt 28 and a radially inwardly extending flange 29 . The skirt 28 defines on an inner surface a thread 30 that matingly engages the thread 16 at the open end.
The illustrated embodiment of the baby bottle 10 includes a secondary seal 32 disposed longitudinally inwardly of the open end 15 for sealing between the skirt 28 and the bottle 10 , as discussed below. The skirt 25 defines a shoulder 34 near a distal extent of the thread 30 . The shoulder 34 extends radially inwardly from the skirt 28 . The shoulder 34 contacts the sealing surface 24 of the sealing membrane 14 . As discussed below, movement of the shoulder 34 actuates the release of the seal of the sealing membrane 14 from the open end 15 of the bottle 10 . A removable nipple guard 36 covers the nipple 20 and is readily re-installed by slipping the guard over the nipple following use of the bottle 10 .
FIG. 2 illustrates an upper perspective view of the sealing membrane 14 in accordance with the present invention. The sealing membrane 14 in the illustrated embodiment is an annular, substantially flat resilient disc with the sealing surface 24 and an opposing anterior flow surface 40 . A plurality of ports 42 are defined in spaced-apart relation in perimeter portions of the sealing membrane 14 . The ports 42 in the illustrated embodiment define semi-circular slots at the perimeter edge of the sealing membrane 14 . Other geometric shapes for the ports 42 may be gainfully used to facilitate the flow from the bottle 10 across the perimeter edge of the sealing membrane 14 when the seal is released, as discussed below. The anterior surface 40 of the sealing membrane 14 in the illustrated embodiment further defines a plurality of anterior bosses 46 that extend from the flow surface. The bosses 46 are spaced-apart and extend radially on the flow surface 40 . The bosses 46 define fluid flow pathways 48 between adjacent bosses. While the ports 42 and the bosses 46 facilitate the flow of the fluids, these features are not necessary to effect and to release the seal in the valving structure of the present invention.
With reference to FIG. 1, the sealing membrane 14 cooperates with the clamp ring 26 to seal the contents of the baby bottle 10 . The nipple 20 is received into the clamp ring 26 with the flange 23 bearing against the flange 29 . The sealing membrane 14 is positioned within the clamp ring 26 with the perimeter edge of the sealing membrane received between the flange 23 of the nipple 20 and the shoulder 34 of the clamp ring. The protruding extension 22 of the nipple 20 extends through the opening defined by the flange 29 of the clamp ring 26 .
The baby bottle 10 is initially filled with a fluid, such as a milk product for a baby. The sealing membrane 14 is placed on the edge 25 of the open end 15 . The clamp ring 26 with the nipple 20 is placed on the baby bottle 10 . The thread 30 engages the thread 16 of the bottle 10 at the open end 15 . The flange 29 of the clamp ring 26 bears against the flange 23 of the nipple 20 and thus against the perimeter portion of the sealing membrane 20 . Tightening the clamp ring 26 by rotating the ring relative to the bottle 10 forces the perimeter portion firmly against the edge of the open end 15 . This seals the bottle 10 to fluid flow from the open end 15 . The nipple guard 36 detachably covers the nipple 20 .
For use, the baby bottle 10 is unsealed. This allows the milk to flow from the bottle 10 past the sealing membrane 14 and through the aperture in the nipple 20 . With reference to FIG. 3, this is accomplished by rotating the clamp ring 26 in a reverse direction. The thread 16 functions as a cam to move the clamp ring 26 longitudinally outwardly relative to the end 15 . The shoulder 34 engages the radially distal edge portion of the sealing membrane 14 . As the clamp ring 26 moves longitudinally, the shoulder 34 induces a release of the sealing engagement of the perimeter portion of the sealing membrane 14 against the end 15 . The shoulder 34 thereby defines an actuator for releasing the sealing engagement of the sealing membrane 14 and the bottle 10 . In the illustrated embodiment, the ports 42 are opened to fluid flow as the portion of the sealing membrane 14 about these ports are likewise released from sealing engagement.
With the bottle 10 then inverted, milk begins to flow through the ports 42 and across the flow surface 40 . The fluid flows along the fluid pathways 48 to the nipple 20 for communicating through the aperture outwardly of the bottle 10 . The bosses 46 bear against a bottom surface of the flange 23 of the nipple 20 to maintain the flow pathways 48 over the flow surface 40 of the sealing membrane 14 . The bosses 46 in an alternate embodiment (not illustrated) are molded integral with the nipple 20 and extend from the flange 23 towards the sealing membrane 14 . The secondary seal 32 seals between the skirt 28 and the bottle 10 to prevent fluid from leaking past the skirt 25 . The clamp ring 26 bears against a perimeter edge of the flange 23 of the nipple 20 to form another secondary seal to prevent fluid flow between these members.
A remaining portion of the contents of the baby bottle 10 are readily resealed therein for subsequent use. The resealing is accomplished by rotating the clamp ring 26 relative to the threaded open end 15 to tighten the clamp ring to the bottle 10 . The flange 29 of the clamp ring 26 again bears against the flange 23 of the nipple 20 and thus against the perimeter portion 44 of the sealing membrane 14 . This forces the perimeter portion firmly against the open end 15 . The bottle 10 is thereby resealed to fluid flow from the open end 15 .
It is to be appreciated with respect to the present invention that the thread provides a satisfactory cam for guiding the longitudinal travel of the clamp ring 26 for unsealing and sealing the sealing membrane 14 . For example, a course thread may provide a {fraction (1/16)} inch longitudinal movement with less than a 120 degree rotation or twist of the clamp ring 26 . Such slight rotational movement is sufficient for the shoulder 34 to induce release of the sealed ports 42 without undue release of the clamping action holding the sealing membrane 14 and the nipple 20 to the open end of the bottle.
The secondary seal 32 that seals inwardly of the edge 25 between the skirt 28 and the bottle 10 in one embodiment is a molded feature of the bottle 10 . In another embodiment, the secondary seal 32 is a resilient ring added to the assembly of the bottle 10 .
The sealing assembly 12 with the sealing membrane 14 and the clamp ring 26 cooperatively provide a novel sealing mechanism that allows a person using the bottle 10 to break and open the seal of the contents by rotatably twisting the clamp ring 26 relative to the bottle 10 and readily reseal the bottle by reverse rotation of the clamp ring. The shoulder 34 moves the sealing membrane 14 to the dispensing position, while the flange 29 moves the sealing membrane to the sealing position. This provides in one aspect a push-pull valving action on the sealing membrane 14 and the end of the bottle 10 for affecting and releasing the seal of the sealing membrane.
It is to be appreciated that a break-away tamper ring (not illustrated) may be detachably engaged to the clamp ring 26 . The clamp ring 26 is not rotatable until the break-away tamper ring is detached. Further, the bottle with the nipple guard 36 may be enclosed with a shrink-wrap type security covering (not illustrated) to provide an additional tamper indicator for retail sale of bottles with sealing membranes in accordance with the present invention. It is to be appreciated that while the specification describes the present invention with respect to a baby bottle, the sealing apparatus is readily usable with a sports drink bottle or the like, in which a dispensing spout with a radially extending flange is received within the clamp ring 26 , for unsealing and sealing the container for subsequent use of the remainder fluids.
The specification has thus described in various embodiments the sealing membrane of the present invention including the manufacture and use thereof. It is to be understood, however, that numerous changes and variations may be made in the construction of the present invention. It should therefore be understood that modifications to the present invention may be made without departing from the scope thereof as set forth in the appended claims. | A baby bottle ( 10 ) having a dispensing member ( 20 ) and a sealing membrane ( 14 ) disposed between the dispensing member ( 20 ) and an open end ( 15 ) of the container ( 10 ). A threaded collar ( 26 ) engages the open end and a shoulder ( 34 ) extends laterally adjacent an extent of the thread. The sealing membrane ( 14 ) includes ports ( 42 ) for communicating fluid therethrough. The sealing membrane ( 14 ) moves from a sealing position with a sealing surface ( 24 ) in bearing contact with the open end ( 15 ) and a dispensing position with the sealing surface ( 24 ) spaced apart from the open end for fluid flow through the ports ( 42 ). The sealing membrane moves in response to the shoulder ( 34 ) moving as the collar ( 26 ) is rotated and moved longitudinally outwardly relative to the end ( 15 ) by the camming action of the thread on the bottle ( 10 ). | 0 |
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
This invention was made under a CRADA (SC10/01775.00) between Kontek Industries, Inc. (along with its subsidiary, Stonewater Control Systems, Inc.) and Sandia National Laboratories, operated for the United States Department of Energy. The government has certain rights in this invention.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application relates to five and co-owned Non-provisional patent applications filed simultaneously to one-another on Sep. 8, 2010 as follows: 1) titled “Security Systems Having Communication Paths in Tunnels of Barrier Modules and Armored Building Modules”, application Ser. No. 12/877,670; 2) titled “Security Systems with Adaptive Subsystems Networked through Barrier Modules and Armored Building Modules”, application Ser. No. 12/877,728; 3) titled “Diversity Networks and Methods for Secure Communications”, application Ser. No. 12/877,754; 4) titled “Autonomous and Federated Sensory Subsystems and Networks for Security Systems”, application Ser. No. 12/877,794; and 5) titled “Global Positioning Systems and Methods for Asset and Infrastructure Protection”, application Ser. No. 12/877,816; the disclosures of which are hereby incorporated by reference in their entireties.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
This invention was made under a CRADA (SC10/01775.00) between Kontek Industries, Inc. (along with its subsidiary, Stonewater Control Systems, Inc.) and Sandia National Laboratories, operated for the United States Department of Energy.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to physical barriers placed along a perimeter of a security area for the purpose of thwarting or at least delaying unwanted intrusions. The barriers may be combined with sensors to enable electronic security systems and methods to automatically and reliably monitor the perimeter for intruders or terrorist threats.
2. Description of the Related Art
Security zones for protecting groups of people and/or facilities be they private, public, diplomatic, military, industrial, or other zones, can be dangerous environments for people and property if threatened by intruders. The prior art in security systems and armored protection provide some solutions but fall far short of being synergistically integrated and are often are too costly and require intense human oversight. Solutions that include the use of sensors have been limited by lower than desirable probability of detection of intrusion attempts, by higher than desirable nuisance alarm rates (NAR), and by higher than desirable false alarm rates (FAR).
In the prior art, automated monitoring and control systems sense disturbances to an ambient condition and cause alarms to be activated, but these systems fall short of being able to adequately identify many relevant cause(s) of a disturbance, and they are not usually applied to detecting attempts at physical intrusion through a physical barrier. U.S. Patent Application Publication No. 2006/0031934 by Kevin Kriegel titled “Monitoring System”, incorporated herein by reference in its entirety, discloses a system that monitors and controls devices that may sense and report a location's physical characteristics through a distributed network. Based on sensed characteristics, the system may determine and/or change a security level at a location. The system may include a sensor, an access device, and a data center. The sensor detects or measures a condition at a location. The access device communicates with the sensor and the data center. The data center communicates with devices in the system, manages data received from the access device, and may transmit data to the access device. However this discloses nothing to provide a physical barrier against intruders accessing the devices that are to be monitored.
Rows of concrete barrier blocks that can slide across the ground can stop and destroy terrorist vehicles that collide with them, and can protect against blast waves and blast debris, but they offer no earlier warning signals of threats. U.S. Pat. No. 7,144,186 to Roger Allen Nolte titled “Massive Security Barrier”, U.S. Pat. No. 7,144,187 to Roger Allen Nolte and Barclay J. Tullis titled “Cabled Massive Security Barrier”, U.S. Pat. No. 7,654,768 to Barclay J. Tullis, Roger Allen Nolte, and Charles Merrill titled “Massive Security Barriers Having Tie-Bars in Tunnels”, and U.S. Pat. No. 8,061,930 to Barclay J. Tullis, Roger Allen Nolte, and Charles Merrill titled “Method of Protection with Massive Security Barriers Having Tie-Bars in Tunnels” all incorporated herein by reference in their entireties, disclose barrier blocks or modules, and barriers constructed of barrier modules. U.S. Pat. No. 7,144,186 discloses barrier modules, each with at least one rectangular tie-bar of steel cast permanently within concrete (or other solid material) and extending longitudinally between opposite sides of the barrier module, wherein adjacent barrier modules are coupled side-against-side by means of strong coupling devices between adjacent tie-bars, and wherein no ground penetrating anchoring means is involved. But since the tie-bars are cast within the barrier modules, they cannot be changed out or upgraded without removing and replacing the solid material as well. However, U.S. Pat. No. 7,144,187 discloses barrier modules of solid material with tunnels extending between opposite sides, wherein adjacent barrier modules are coupled side-against-side with cables passing through the tunnels and anchored to sides of at least some of the barrier modules by anchoring devices. And U.S. Pat. No. 7,654,768 discloses barrier modules that have tie-bars in tunnels that extend longitudinally between opposite sides of a barrier module. U.S. Pat. No. 8,061,930 discloses methods for providing protection from a terrorist threat by using the above barrier modules that have tie-bars in tunnels. Whereas barriers of concrete blocks provide impressive protection against breeches by vehicles and explosives, they provide alone little to prevent humans from climbing over them.
U.S. Pat. No. 8,210,767 to David J. Swahlan and Jason Wilke titled, “Vehicle Barrier with Access Delay” discloses an access delay vehicle barrier for stopping unauthorized entry into secure areas by a vehicle ramming attack. The barrier disclosed includes access delay features for preventing and/or delaying an adversary from defeating or compromising the barrier. A horizontally deployed barrier member can include an exterior steel casing, an interior steel reinforcing member and access delay members disposed within the casing and between the casing and the interior reinforcing member. Access delay members can include wooden structural lumber, concrete and/or polymeric members that in combination with the exterior casing and interior reinforcing member act cooperatively to impair an adversarial attach by thermal, mechanical and/or explosive tools. However, this solution alone does little to prevent humans from easily climbing over or under its structure.
In a paper titled, “A low cost fence impact classification system with neural networks” by J. de Vries in the 7th AFRICON Conference in Africa, 17 Sep. 2004, Vol. 1, pp. 131-136, a system is proposed for securing property to prevent livestock theft and farm intrusions. The paper reports a system that analyzes vibrations sensed by a point sensor to detect intrusions past a game farm or security fence, and since the point sensor can detect vibrations generated at a distance from the sensor, owners of protected property can receive early warnings. Different types of intrusions can be distinguished if they generate different vibrations. But use is made of only one type of sensor, a point vibration sensor on each horizontal wire of a wire fence. Avoiding challenges of dealing with signals varying in amplitude and duration caused by variation in distances of fence disturbances from a sensor, the author chose to use cross-correlations to detect events on wires and then input those events as ones into a feature set defined by wire number and time slots.
In the 2004 Proceedings of the 37th Hawaii International Conference on System Sciences, a paper titled, “Intrusion Sensor Data Fusion in an Intelligent Intrusion Detection System Architecture”, by Ambareen Siraj, Rayford B. Vaughn, and Susan M. Bridges, the authors state, “most modern intrusion detection systems employ multiple intrusion sensors to maximize their trustworthiness.” They also say, “The overall security view of the multisensory intrusion detection system can serve as an aid to appraise the trustworthiness in the system.” Their paper presents their research effort in that direction by describing a Decision Engine for an Intelligent Intrusion Detection System (IIDS) that fuses information from different intrusion detection sensors using an artificial intelligence technique. The Decision Engine uses Fuzzy Cognitive Maps (FCMs) and fuzzy rule-bases for causal knowledge acquisition and to support the causal knowledge reasoning process. However, their paper deals only with detecting intrusions into electronic communication traffic and does not anticipate utilizing interactions of sensors with elements of a physical barrier structure, and it does not disclose use of sensors that corroborate one another in a complementary way by virtue of being physically connected to a common structure experiencing a disturbance.
U.S. Pat. No. 5,091,780 by Pomerleau titled, “A trainable security system and method for the same”, discloses a security system comprising a processing device for monitoring an area under surveillance by processes images of the area to determine whether the area is in a desired state or an undesired state. The processing device is said to be trainable to learn the difference between the desired state and the undesired state. The processing device includes a computer simulating a neural network. However, it is well known that image sensors use limited fields of view, and that neural nets operating on imaging data can be fooled by camouflaged intruders, very rapid changes, and a wide diversity of weather.
U.S. Pat. No. 5,517,429 by Harrison titled, “Intelligent area monitoring system”, discloses an intelligent area monitoring system having a plurality of sensors, a neural network computer, a data communications network, and multiple graphic display stations. The neural network computer accepts the input signals from each sensor. It is asserted that any changes that occur within a monitored area are communicated to system users as symbols which appear in context of a graphic rendering of the monitored area to represent the identity and location of targets in the monitored area. The disclosed system attempts to identify objects by sensed attributes their locations, but is insufficient to detect or identify intrusive actions. Furthermore, “any changes” may include those scene changes responsible for what would desirably be categorized as nuisance alarms or even false alarms, and no such classification and identification is disclosed. The disclosed system doesn't comprise a physical security barrier nor is it combined with one, nor does it therefore exploit in any way the manner of mounting sensors to a common structure.
U.S. Pat. No. 8,253,563 by Burnard, et al. titled, “System and method for intrusion detection”, discloses an invention that may be employed in intruder and vehicle alarm systems. The disclosure states, “Present day intrusion detection systems frequently cause false alarms by mistaking occupants as intruders, and it is desirable to reduce such false alarms.” Their invention uses a processor that receives sensor signals over temporal periods and employs various software algorithms to statistically discern various activities, thereby attempting to reduce false alarms and detection failures. They state that the typical nature of activities is such that noise occurs frequently, normal activities occur less frequently, and abnormal activities occur least frequently. The algorithms apply logic statements to infer that information with a high probability of occurrence may be noise, information with a lower probability of occurrence may be normal activity, and information with the least probability of occurrence may be abnormal activity. Furthermore their system adjusts thresholds to obtain a predetermined false alarm rate. Something better is needed for a security barrier to reduce to a minimum both false alarm rates and nuisance alarm rates.
U.S. Pat. No. 8,077,036 by Berger et al. titled, “Systems and methods for security breach detection”, discloses a system for detecting and classifying a security breach, one that may include at least one sensor configured to detect seismic vibration from a source, and to generate an output signal that represents the detected seismic vibration. The system may further include a controller that is configured to extract a feature vector from the output signal of the sensor and to measure one or more likelihoods of the extracted feature vector relative to set of breach classes. The controller may be further configured to classify the detected seismic vibration as a security breach belonging to one of the breach classes by choosing a breach class within the set that has a maximum likelihood. But not all breeches of a fence or other physical barrier can be detected by sensing only seismic vibrations.
U.S. Pat. No. 7,961,094 by Breed titled, “Perimeter monitoring techniques”, discloses a method for monitoring borders or peripheries of installations and includes arranging sensors periodically along the border at least partially in the ground, the sensors being sensitive to vibrations, infrared radiation, sound or other disturbances, programming the sensors to wake-up upon detection of a predetermined condition and receive a signal, analyzing the signal and transmitting a signal indicative of the analysis with an identification or location of the sensors. The sensors may include a processor embodying a pattern recognition system trained to recognize characteristic signals indicating the passing of a person or vehicle. Whereas it is disclosed to apply pattern recognition techniques to each sensor individually, what is needed are more powerful techniques that apply pattern recognition techniques to a set of sensors as a whole, and in particular to a group of sensors of different types.
In a paper titled, “Machine Learning that Matters”, by Kiri L. Wagstaff, published in the Proceedings of the Twenty-Ninth International Conference on Machine Learning (ICML), June 2012, it is stated that much of current machine learning (ML) research has lost its connection to problems of import to the larger world of science and society. What are needed are more applications of machine learning techniques to real-world applications such as improving the probabilities of detection of intruder or terrorist activities while minimizing false alarms rates and nuisance alarm rates.
BRIEF SUMMARY OF THE INVENTION
An intrusion delaying barrier is disclosed which includes primary and secondary physical structures and can be instrumented with multiple sensors incorporated into an electronic monitoring and alarm system. Such an instrumented intrusion delaying barrier may be used as a perimeter intrusion defense and assessment system (PIDAS). Problems with not providing effective delay to breaching by intentional intruders and/or terrorists who would otherwise evade detection are solved by attaching two or more of the secondary structures to the primary structure, and attaching at least some of the sensors to those secondary structures. By having multiple sensors of various types physically interconnected serves to enable sensors on different parts of the overall structure to respond to common disturbances and thereby provide effective corroboration that a disturbance is not merely a nuisance or false alarm. Use of a machine learning network such as a neural network exploits such corroboration.
Beyond providing improved physical protection, some example embodiments of the present invention(s) utilize the improved physical barriers along with a variety of sensors, machine-learning methods, apparatus, and systems to achieve physical barriers along with reconnaissance sensors and signal processing which, when compared with prior systems, enable increased probability of detection while reducing both nuisance alarms and false alarms. Examples of the types of areas or sites that can benefit from this kind of a self-monitoring barrier include military sites, embassies, nuclear sites, chemical facilities, communications facilities, and areas including personnel and/or strategically sensitive assets.
Prior art had not discovered the benefits and practicality of mounting a fence to a Normandy type barrier, or to a barrier comprising a row of concrete blocks tied together by a chain of steel bars. And prior art of combining security barriers with sensors had failed to more fully exploit synergistic integration of primary physical barrier structure with secondary structures used to mount selected sensors in a manner that utilizes the overall physical barrier structure to enhance the effectiveness of the sensors, or to utilize a variety of sensor types that can complement one another to reduce nuisance alarm rates (NAR) and false alarm rates (FAR).
The present inventions are pointed out with particularity in the appended claims. However, some embodiments and aspects of the inventions are summarized herein.
One embodiment of the inventions is an intrusion delaying barrier comprising 1) a primary structure selected from the group consisting of i) a steel beam supported by cross-bucks standing on top of the ground and ii) a row of concrete blocks sitting on top of the ground, wherein the row of concrete blocks is bound end-against-end by a chain of steel tie-bars; and 2) a secondary structure selected from the group consisting of a chain link fence, a welded mesh fence, and a wire fence; wherein a majority of weight of the secondary structure is supported by the primary structure; and wherein neither the primary structure nor the secondary structure is planted into the ground. This embodiment may include multiple sensors, multiple sensor support structures, an alarm status indicator, and a computer in communication with the multiple sensors and the alarm status indicator; wherein the computer may generates an output to the alarm status indicator when an intrusion attempt disturbs the barrier. The computer may be one that processes instructions simulating a first machine learning network that takes as inputs data from two or more of the multiple sensors. A second machine learning network may be included; wherein the intrusion delaying barrier may have a length axis that forms a dividing line between a more secure side and a less secure side; wherein the first and second machine learning networks may be connected to different groups of sensors of the multiple sensors; and wherein the first and second machine learning networks may monitor primarily their respective segments along the length dimension. The first machine learning network may include an artificial neural network. The alarm status indicator may be controlled by the computer to be an indicator of degree of correlation among at least two of the multiple sensors in sensing at least an intrusion attempt; and wherein the degree of correlation may be based on probabilities that disturbances to the sensors may be from an attempted intrusion. The first machine learning network may actively discriminate against nuisance conditions and/or against false alarm conditions. The multiple sensors may include at least three sensors that are each of a different type of sensor based on different transducer principles; wherein status of the alarm status indicator may be controlled by the computer to be a function of degree of correlation between at least two of the multiple sensors in sensing an intrusion attempt, and wherein the at least two of the multiple sensors are not of the same type of sensor. And the at least three sensors may be supported structurally by the barrier by respectively different mounting devices selected from the group consisting of a fence, a wire, a cable, a conduit, a tube, a bar, a pole, a wall, a cantilever, a panel, a bridge, a tower, and a horizontal channel. The steel beam supported by cross-bucks may be part of a Normandy type of barrier, or of a modified Normandy barrier such as disclosed in U.S. Pat. No. 8,210,767.
In another embodiment of the inventions, an intrusion delaying barrier comprises: 1) a contiguous series of interconnected steel beams that help to form a dividing line between a secure area of ground on one side of the beams and a less secure side on the other side of the beams; 2) multiple sensors; 3) multiple types of mechanical support structures each connecting one of the multiple sensors to the chain of interconnected steel beams; 4) an alarm status indicator; and 5) a computer in communication with both the multiple sensors and the alarm status indicator; wherein the multiple sensors include at least three different types of sensors based on different transducer principles; and wherein a status of the alarm status indicator is controlled by the computer to be a function of degree of correlation among at least two of the at least three different types of sensors in sensing at least an intrusion attempt. The steel beams of this embodiment may weigh at least fifteen kilograms per linear meter along the divide. The steel beams may be included in one selected from the group consisting of a Normandy type of barrier and a row of concrete blocks, wherein the blocks are bound together by the steel beams. The Normandy type of barrier may be a modified Normandy barrier such as disclosed in U.S. Pat. No. 8,210,767. At least one of the mechanical support structures may be connected to the steel beams and comprises one selected from the group consisting of a fence, a wire, a cable, a conduit, a tube, a bar, a pole, a wall, a cantilever, a panel, a bridge, a tower, and a horizontal channel. The degree of correlation may be based on probabilities that disturbances to the sensors are caused by attempted intrusion. The computer may include a machine learning network, which may include an artificial neural network, to which are fed data from the at least two of the at least three different types of sensors. And the machine learning network may actively discriminate against nuisance conditions and/or against false alarm conditions.
Yet another embodiment of the inventions may be a method of configuring a security barrier, the security barrier comprising both a physical barrier to delay or stop intruders and a system of sensors useful to detect intrusion attempts, the method comprising steps of: 1) installing the physical barrier; 2) installing the sensors to the physical barrier; 3) installing communication media for communication between the sensors and an alarm annunciator; 4) installing additional communication media for communication between at least one computer and two or more of the sensors; and 5) providing the at least one computer with instructions to execute a machine learning algorithm to transform sensor outputs into alarm outputs for the alarm annunciator; wherein no concrete or steel element of the physical barrier is buried in the ground. The method may further comprise the step of using the security barrier to delay or stop intruders, or at least detect intrusion attempts by would-be intruders.
Objects and Advantages of the Invention
Objects and advantages of the present invention include security barriers and security barrier systems that significantly out-perform those of the prior art, and at a lower cost per unit length. This is accomplished by merging together physical barrier structures of different types, and also by integrating these compound physical barriers with electronic security systems to exploit sensor interactions with structural components of the physical barrier. The objects and advantages are also to achieve security barriers that use sensors and artificial intelligence to improve probability of detecting and classifying attempts at intrusion and with a reduced false alarm rate and reduced nuisance alarm rate.
Further advantages of the present invention will become apparent to ones skilled in the art upon examination of the accompanying drawings and the following detailed description. It is intended that any additional advantages be incorporated herein.
The various features of the present invention and its preferred embodiments and implementations may also be better understood by referring to the accompanying drawings and the following detailed description. The contents of the following description and of the drawings are set forth as examples only and should not be understood to represent limitations upon the scope of the present invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The foregoing objects and advantages of the present invention may be more readily understood by one skilled in the art with reference being had to the following detailed description of several embodiments thereof, taken in conjunction with the accompanying drawings. Within these drawings, callouts using like reference numerals refer to like elements in the several figures (also called views) where doing so won't add confusion, and primes and double-prime suffixes are used to identify copies related to a particular embodiment, usage, and/or relative location. Within these drawings:
FIG. 1 shows a perspective view of a portion of one embodiment of an intrusion delaying barrier equipped with a variety of sensors and revealing one-half of a pass-through opening.
FIG. 2 shows a side view of the portion of barrier shown in FIG. 1 and includes a vertical cross-section taken through the pass-through opening and the ground, revealing a buried seismic sensor.
FIG. 3 shows a portion of a barrier-continuity sensor mounted within a channel.
FIG. 4 shows overlapping beams and fields-of-view associated with photosensor components protecting the pass-through.
FIG. 5 shows both a frontal and end view of a section or module of cross-buck-supported barrier beams, and shows optional roll bars holding optional roll-bar-mounted sensors not shown in the previous figures.
FIG. 6 shows a perspective view of a portion of a second embodiment of an intrusion delaying barrier equipped with a variety of sensors and revealing a pass-through opening.
FIG. 7 shows a perspective view of a portion of a third embodiment of an intrusion delaying barrier equipped with a variety of sensors and revealing a pass-through opening.
FIG. 8 shows a diagram depicting neighboring sections of intrusion delaying barrier with a variety of sensors associated with each section connected respectively to a computer at each section, wherein the computers at the sections are connected to another computer remote from the barrier.
FIG. 9 shows a diagram of an embodiment of a sensor subsystem connected to another computer.
FIG. 10 shows a pictorial depiction of a computerized sensor subsystem.
FIG. 11 shows a pictorial depiction of a compact embodiment of a sensor transducer or of a sensor subsystem.
FIG. 12 shows a representation of an embodiment of an artificial neural network.
FIG. 13 shows a two-step process 500 embodiment of simulating neuron activation.
FIG. 14 shows an embodiment of a cost function for an artificial neural network.
FIG. 15 shows more detail of the first of the two steps shown in FIG. 13 used in computations to simulate neuron activations.
FIG. 16 shows some of the computational steps used in an embodiment of backward propagation used to seek a minimum of the cost function shown in FIG. 14 .
FIG. 17 shows steps in an embodiment of a method for creating and teaching an artificial neural net.
DETAILED DESCRIPTION OF THE INVENTION
The following is a detailed description of the invention and its preferred embodiments as illustrated in the drawings. While the invention will be described in connection with these drawings, there is no intent to limit it to the embodiment or embodiments disclosed. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims.
While each sensor added to a perimeter may increase probability of intruder detection, each sensor added to a perimeter increases significantly the potential volume of nuisance and false alarms personnel must respond to, if traditional approaches are used in combining the information from the various sensors. The traditionally accepted practice for reducing nuisance and false alarms has been to tune down the sensitivity of particular sensors until an acceptable compromise is found between nuisance alarms and detection capability, thereby making a concession in favor of the intruder. Another traditional approach has been to use expert systems to make decisions based on logic in merging the output of two or more sensors to assess whether an event qualifies as an alarm. For example, methods which perform a logical AND on the alarm state output of separate sensors, effectively combine the weaknesses of the sensors as well as their strengths and result in probabilities of detection that are significantly lower than the sensors managed separately. These traditionally popular solutions can result in less capable systems that are not too difficult for an intruder to compromise. Exceptions exist when, for example, as when some sensors are known to be both highly sensitive and have very low nuisance and false alarm rates, and in such cases it can be desirable to use logic rules to combine their outputs with those of one or more learning machines that process the other sensors. Nevertheless, the current invention(s) provide(s) a better approach than using exclusively logical rules to combine sensor outputs.
The current invention(s) provide(s) the approach of combining sensor outputs in a way that increases overall probability of detection of intrusion attempts while simultaneously and dramatically reducing the incidence of false and nuisance alarms, with few poor tradeoffs. In order to accomplish this, richer data from the sensors than just threshold crossings are fed to a machine learning network such as a computer simulated artificial neural network or a probabilistic inference engine, and secondary structures are attached directly to the primary structure of the barrier in manners that enable sensors mounted to these structures to have increased ability to respond to disturbances of the barrier they wouldn't have otherwise.
Kontek Industries, Inc. and its subsidiary, Stonewater Control Systems, worked with Sandia National Laboratories on a shared project to build an alternative to a traditional PIDAS (perimeter intrusion detection and assessment system) that can offer improved security at a fraction of cost in time and money compared with the traditional systems. By furnishing a low-cost single line perimeter fence with multiple independent but complementary sensor technologies, they were able to achieve their goal of a lower cost physical barrier having automated reconnaissance to discourage or at least delay intrusion attempts by hostile vehicles and/or terrorist individuals. And by applying the current invention(s) to embodiments of that improved PIDAS, the project achieved also surprisingly good results in improved probability of detection and reduced rates of false and nuisance alarms.
A paper titled, “Design and Performance Testing of an Integrated Detection and Assessment Perimeter System”, by Jeffrey G. Dabling, James O. McLaughlin, and Jason J. Andersen, in IEEE Paper No. ICCST-2012-28 presented 15-18 Oct. 2012 in Boston, Mass., discloses work and testing results performed under the above-mentioned project. The paper describes test results of the jointly developed and evaluated integrated perimeter security solution, one that couples access delay with detection and assessment. This novel perimeter solution was designed to be sufficiently flexible for implementation at a wide range of facility types, from high security military or government installations to commercial power plants, to industrial facilities of various kinds A prototype section of barrier was produced and installed at the Sandia Exterior Intrusion Sensor Testing Facility in Albuquerque, N. Mex. The prototype was implemented with a robust vehicle barrier and coupled with a variety of detection and assessment solutions to demonstrate both the effectiveness of such a solution, as well as the flexibility of the system. In this implementation, infrared sensors, a fiber-optic sensor, and fence disturbance sensors were coupled with a video motion detection sensor and seismic sensors. The ability of the system to properly detect pedestrian or vehicle attempts to bypass, breach, or otherwise defeat the system was demonstrated and characterized, as well as a reduced nuisance alarm rate. Products which may incorporate the current invention(s) will be marketed under the ReKon™ name.
DEFINITIONS
Within this disclosure and claims, “barrier” is defined to mean a physical structure intended to stop or delay passage across it, through it, or under it by intruders or otherwise hostile forces.
Within this disclosure and claims, “intruder” is defined to mean any person or vehicle that at least attempts to breech a barrier by going across it, through it, or under it, or attempts to damage the barrier.
Within this disclosure and claims, “Normandy type of barrier” is defined to mean any barrier that includes a structural main beam parallel to the ground surface and which is supported above the ground surface by cross-bucks. And, “modified Normandy barrier” will mean a Normandy type of barrier that has strengthening beams within the aforementioned structural main beam.
Within this disclosure and claims, “a disturbance” is defined to mean a physical response of a barrier (or of something attached to the barrier) resulting from an action by an intruder or an attempted intruder. The action can be induced by an intruder or attempted intruder and may be made directly or indirectly to the barrier and/or the surroundings or the barrier. One example of a disturbance would be a vibration induced in a barrier, or in something attached to the barrier, by an intruder climbing over the barrier. Another example would be a vehicle or person running or driving toward a barrier as sensed by a seismic sensor associated with the barrier.
Within this disclosure and claims, “transducer” is defined to mean that part of a sensor that transforms one form of energy to another and that responds to a change in physical, electrical, magnetic, electromagnetic, optical, acoustical, or chemical property or condition by effecting a change in an output value. Transducers types include, for example, capacitive, inductive, ultrasonic, electromagnetic (antenna, CCD, CMOS arrays), weight measuring, temperature, acceleration, chemical, sound or other types of sensing device.
Within this disclosure and claims, “sensor” is defined to mean a device or system that includes a transducer and changes a physical quantity or behavior into a signal for electronic processing.
Within this disclosure and claims, “discrimination” is defined to mean automated classification of an event or condition into at least one of two or more categories. The event or condition is generally sensed by one or more sensors.
Within this disclosure and claims, “pattern detection” and “pattern recognition” are defined to mean classification of one or more response signals (or sensor data) generated by one or more sensors (or sensor systems or subsystems) associated with a mechanical barrier intended to delay breeching by intrusive or otherwise hostile actions. These terms are furthermore defined to mean automated processing of data and/or signals from one or more sensors associated with a barrier to determine or classify the identity of an object, condition, event, or a combination thereof that has influenced or is influencing the sensor(s) (e.g. causing a disturbance). Examples of such influences include acoustic vibrations; shaking or striking of barrier structure or sensors; cutting or heating of barrier structure or sensors; images of a barrier and/or its surroundings; weather; foot-steps; animal activity; vehicle-caused ground vibrations; vehicle-caused sounds; gases such as vehicle exhaust; structural vibrations; gun-shots; explosions; object motions; object locations; electric fields; magnetic fields; electromagnetic waves (e.g.: visible light, infrared radiation, radar, electronic communications, and engineered activity of an electromagnetic nature at any frequency); and even their relationships to one-another. Pattern recognition may involve measurements of features, extraction of derived features as attributes, comparison with known patterns to determine a degree of correlation or of a match or mismatch, and/or determining system parameters that affect recognition. Pattern recognition may classify patterns in data and/or signals based on either a priori knowledge or on statistical information extracted from the patterns. The patterns to be classified are usually groups of measurements defining points in an appropriate multidimensional space.
Within this disclosure and claims, “machine learning system” and “machine learning network” are defined to mean one or more systems or apparatuses that are trained to automatically perform steps of pattern detection or pattern recognition. The classification scheme is usually based on the availability of a set of patterns that have already been classified or described. This set of patterns is termed the training set and the resulting learning strategy is characterized as supervised. Learning may also be unsupervised, in the sense that the system is not given an a priori labeling of patterns; instead unsupervised learning establishes the classes based on the statistical regularities of the patterns and without availability of a set of patterns that have already been classified or described. The classification scheme usually uses one of the following approaches: statistical (or decision theoretic), syntactic (or structural), or neural. Statistical pattern recognition is based on statistical characterizations of patterns, assuming that the patterns are generated by a probabilistic system. Structural pattern recognition is based on the structural interrelationships of features. Neural pattern recognition employs the neural computing paradigm that has emerged with artificial neural networks. Machine learning, for the most part, avoids explicit programming that requires logic rules based on knowledge of researchers and/or experts relative to the physical behavior of a barrier or of barrier intrusions. However, other algorithms can be used in addition, such as fuzzy logic, and/or sensor fusion that uses logic rules. The learning algorithm(s) used is/are stored and executed by a computer.
Within this disclosure and claims, “artificial neural network” (or simply “neural network”) is defined to include all pattern learning algorithms (stored in a computer memory, or implemented as circuit hardware) including cellular neural networks, kernel-based learning systems having network structures, and cellular automata. A “combination neural network” as used herein will generally apply to any combination of two or more neural networks that are either connected together or that analyze all or a portion of the input data. A combination neural network can be used to divide up tasks in solving a particular pattern recognition problem. For example, one neural network can be used to classify as an alarm condition disturbance to a barrier caused by someone sawing an element of the barrier structure or its extensions, and a second neural network can be used to classify as a nuisance alarm condition an animal rubbing against a barrier. In another case, one neural network can be used merely to determine whether the sensor data is similar to that upon which a main neural network has been trained or whether there is something radically different about this data and therefore that the data should not simply be classified as an actionable alarm state. For the purposes of this disclosure and claims, an artificial neural network is a) constructed in hardware, b) emulated in software, or c) a combination of hardware construction and emulation software. Due to current state-of-the-art and its resultant limitations in availability of hardware architectures that can execute artificial neural network behavior (responses) in a truly distributed manner, most artificial neural networks today are emulated by running software in one or more serial processors. Much of the high-level programming is carried out using linear algebraic operations on matrices and vectors, and thereafter compiled or assembled to machine level code. A huge advantage of using artificial neural networks to classify patterns based on a large number of input features is the ability to classify the outputs of highly non-linear functions (behaviors) without having to compute regressions on high-order polynomials of those input features. Artificial neural networks typically use highly non-linear classification functions such as the logistic function (see FIG. 13 and its description below) to help sort patterns into categories each associated with a value of unity or zero, for example.
Within this disclosure and claims, “nuisance alarms” and “false alarms” are generally defined to mean alarms that are not indicators of true concern to those being protected by a barrier, which is to say that they do not accurately report true intrusions or attempts at intrusion by would-be intruders or other hostile actions to a barrier. More specifically, nuisance alarms are those that have resulted from some real effect but which are not desired as true alarms such as when an animal rubs against a barrier, or a sudden change in sunlight disturbs a photosensor. And also more specifically, false alarms are those that result from errors in classification or otherwise from errors in the functioning of sensors or other hardware or software.
Several embodiments of the current invention(s) and their aspects are described in some detail in the following paragraphs with reference to the figures.
FIG. 1 shows a perspective view of a portion of one embodiment of an intrusion delaying barrier 10 equipped with a variety of sensors 50 , 52 , 54 , 56 , 64 , 66 , 66 ′, 68 , 70 , 72 , and 90 and revealing one-half of a pass-through opening 18 . The intrusion delaying barrier 10 divides an area of ground 16 in a protected area 12 from an area of ground 16 in an unprotected area 14 . The physical structure part of the barrier 10 includes a Normandy type of barrier 20 which comprises a generally horizontal primary beam 22 supported off of the ground by cross-bucks 24 that are positioned at intervals along the major length of the primary beam 22 . Each cross-buck comprises a pair of tilted beams: a back-leaning beam 26 and a forward leaning beam 28 , where “backward” and “forward” are relative to one standing in the protected area 12 viewing outward toward the unprotected area 14 . A generally horizontal secondary beam 30 is shown added parallel to the primary beam 22 . For strength, the cross-bucks 24 , primary beam 22 , and secondary beam 30 are firmly attached to one another as by welding. The primary beam 22 and cross-bucks 24 can be configured as a Normandy type of barrier, or as a modified Normandy barrier as disclosed in U.S. Pat. No. 8,210,767 to David J. Swahlan and Jason Wilke. Additional beams (not shown) parallel to the primary beam 22 may also be attached to the cross-bucks and can be used for added strength as well as to protectively route sensor and other cabling (also not shown) along the barrier.
FIG. 1 also shows that the intrusion delaying barrier 10 includes a screen fence 40 . The screen fence 40 of this embodiment comprises a screen 44 and support posts 40 , wherein the support posts 40 are mounted to the cross-bucks 24 rather than being anchored into the ground 16 . The screen 44 is mounted to the support posts 40 . With such an above-ground configuration, the barrier 10 forms an integral unit of beam 22 and fence 40 . This integration enables the fence 40 to remain attached to the cross-bucks 24 should a vehicle collide with the barrier 10 and move it across the ground's surface 16 . In the embodiment shown, the fence 40 is a chain-link fence, however the screen fence 40 can be any of a variety of fence types including a chain-link fence, a mesh-screen fence, or even a simple farm fence comprised mostly of horizontal wires. In the embodiment shown, the fence 40 is a chain-link fence.
FIG. 1 also shows a number of sensors 50 , 52 , 54 , 56 , 64 , 66 , 66 ′, 68 , 70 , 72 , and 90 . These are only examples of sensors, in type and/or number, which can be incorporated into embodiments of the current invention(s) of intrusion delaying barriers. Other embodiments of the current invention could use selections from any sensors that could, when used on or near an intrusion delaying barrier, output analog and/or digital signals in response to an attempted intrusion or to an actual intrusion of the barrier. One sensor is a vibration sensor 50 shown mounted directly to the primary beam 22 . A second sensor is a photon bar sensor 52 that comprises a vertical array of photon sensors 54 comprising photon emitters and/or receivers. As FIG. 1 is a perspective view looking outward from within a pass-through opening 18 that passes through the barrier 10 , only one side of the opening 18 is shown; therefore a complementary oppositely-facing photon bar sensor 52 ′ on the opposite side of the opening 18 cannot be shown in this view. If there is nothing passing between the oppositely facing bars 52 , some photons emitted from each photon emitter 54 on either of bars 52 or 52 ′ will be received by respectively located photon detectors 54 on the respective bar 52 ′ or 52 . A third sensor is a bridge sensor 56 that is configured as a channel or plate on the ground 16 bridging the gap that is the pass-through opening 18 . A fourth sensor is cable sensor 64 shown fastened to the screen fence 40 ; in the embodiment shown, lengths of such cable are shown running horizontally along a length of the screen fence 40 and at three different elevations off of the ground 16 . A fifth sensor 66 ′ and multiple instances of a single sixth sensor 66 are seismic sensors. The seismic sensor 66 ′ is shown attached to a cross-buck 24 holding it above and off of the ground surface 16 . The seismic sensors 66 are actually underneath the ground surface 16 , but in this view they are each represented with by a circle on the ground surface 16 in order to mark their general locations. A seventh sensor is a camera 68 supported above the barrier by a tower structure 82 . The tower structure 82 may be physically attacked to the barrier 10 , for example near the tower base 84 . An eighth sensor is a weather sensor 70 mounted to a tower-top mounting unit 80 . A ninth sensor is a tower sensor 72 that is also mounted to the tower-top mounting unit 80 . A tenth sensor is a barrier continuity sensor 90 (not shown here, but is shown in FIG. 3 ) that would for example be mounted inside of one of the generally horizontal beams, for example the primary beam 22 or the secondary beam 30 .
FIG. 1 provides a reference for discussion regarding how some sensors are mounted to some structures in this and some other of the possible embodiments of the current invention(s). It is an aspect of the current invention(s) that at least some of the sensors should not be used solely as islands of disturbance detection. By that is meant that the present invention(s) make opportunistic use of collections of sensors, some of the same type and/or some of different types, in order to discriminate actual intrusion activities from causes of what could otherwise result in nuisance alarms or in false alarms. This is accomplished by employing sensor mounting structures that facilitate the ability of the sensors to respond to disturbances to which they might not otherwise respond. For example, if a cable sensor 64 was on a fence not attached mechanically to cross-bucks 24 holding a primary beam 22 , then it most probably would not respond to disturbances made to the primary beam 22 . Similarly, if the primary beam 22 was not connected in some way structurally to the fence that holds a cable sensor 64 , then disturbances to the primary beam 22 , sensed by the vibration sensor 50 mounted to the primary beam 22 , would most likely not be sensed by the cable sensor 64 . By mechanically interconnecting the various sensors by way of their mounting structures, more of the sensors can be responsive to a particular intrusion activity. More is said on this topic in the paragraphs below that discuss the use of machine learning engines, such as artificial neural networks, to transform multiple sensor signals (analog and/or digital) into meaningful alarms. But before proceeding to descriptions of the later figures, note that all of the sensors described for the embodiment 10 shown in FIG. 1 , with the exception of the seismic sensors 66 that are underground, are interconnected by way of the barrier structures and their appendages. The attachment of the tower structure 82 to the rest of the barrier 10 is better shown in FIG. 2 .
FIG. 2 shows a side view of the portion of barrier 10 shown in FIG. 1 and includes a vertical cross-section taken through the pass-through opening 18 and the ground beneath the ground surface 16 , revealing a seismic sensor 66 buried in the ground. This view more clearly shows the relationship of the tower structure 82 to the rest of the structures. A tower fastener 86 is shown which attaches the tower structure 82 to the primary beam 22 . In this embodiment, the tower base 84 is shown to be a steel plate but can be of other forms. Also, screen fence holders 46 are shown fastened at the top of the forward leaning beam 28 and bottom of back-leaning beam 26 of a cross-buck 24 where they fasten the cross-buck 24 to the fence support post 42 , and holding the post 42 on or above the ground surface 16 . In this view, the bridge sensor 56 is obstructing a view of the bottom of the fence support post 42 . Other items shown have the same callouts as in FIG. 1 .
FIG. 3 shows both an end view and a frontal view of a portion of a barrier-continuity sensor 90 mounted within a channel within the secondary beam 30 . In this embodiment, the barrier continuity sensor 90 is a cable such as a fiber-optic cable, and it is shown entering and exiting the secondary beam 30 through holes 38 located near the left and right ends of the secondary beam 30 as oriented in this view. Sections 36 of the secondary beam 30 are cut-away in this view only in order to show details of how the barrier-continuity sensor 90 is mounted within and to the opposite ends (left and right hand ends in this view) of the secondary beam 30 . The cable of the barrier-continuity sensor 90 is held to end-caps 32 of the secondary beam 30 by means of cable fasteners 34 . Any intrusion attempt that severs or bends the secondary beam will cause a detectable disturbance or interruption of the communication carried by the cable of the barrier continuity sensor 90 .
FIG. 4 shows overlapping fields-of-illumination 62 and fields-of-view 60 associated with photon sensors 54 and 54 ′ (associated with their emitters and receivers) as used on the photon bar sensor 52 shown in FIGS. 1 and 2 (and the oppositely facing photon bar sensors 52 shown in FIGS. 6 and 7 ). By mounting the photon sensor bars 52 directly the support posts 42 of the screen fence 40 , the photon sensors 54 can respond not only to objects passing through the pass-through opening 18 , but also to disturbances to the screen fence 40 and other barrier disturbances, and this can be exploited in the present invention(s) as discussed further in sections below.
FIG. 5 shows both a frontal and an end view of a section or module of a Normandy type of barrier consisting of cross-buck-supported barrier beams (cross-bucks 24 ) supporting a primary beam 22 and a secondary beam 30 ). Optional roll bars 94 holding optional roll-bar-mounted sensors 96 (not shown in the previous figures) are shown as a modification. The roll bars 94 help to prevent rolling of the barrier if the barrier is stuck by a vehicle. Being cantilevers extending from the primary beam 22 , the roll bars are subject to vibrations whenever the barrier, or other things attached to the barrier, is disturbed. Thus the roll-bar-mounted sensors 96 can be responsive to a wide variety of barrier disturbances, and this can be exploited in the present invention(s) as discussed further in sections below.
FIG. 6 shows a perspective view of a portion of a second embodiment of an intrusion delaying barrier 10 ′ equipped with a variety of sensors 50 , 52 , 54 , 56 , 64 , 66 , 66 ′, 68 , 70 , 72 , and 90 and revealing a pass-through opening 18 . In this view which is somewhat similar to the perspective view in FIG. 1 of a portion of the first embodiment of an intrusion delaying barrier 10 , both sides of the pass-through opening 18 are visible. A photon bar sensor 52 is indicated along each of the two fence support posts 42 that border the pass-through opening 18 . In this second embodiment, the Normandy type barrier of the first implementation shown in FIG. 1 is replaced by a row of concrete barrier blocks 98 such as, for examples, those disclosed in U.S. Pat. Nos. 7,144,186; 7,144,187; 7,654,768; and 8,061,930; wherein the blocks are bound to one-another by means of interconnected steel bars or even by one or more cable(s) or chain(s). The barrier continuity sensor 90 is protected inside of the secondary beam 30 (as shown in FIG. 3 ) which, in this second embodiment 10 ′, is attached, for example, to the row of the blocks 98 . The seismic sensor 66 ′ is attached, for example, to the top of one of the barrier blocks 98 , whereas other seismic sensors 66 are buried under the ground 16 at locations indicated in the unprotected area 14 . The screen fence 40 is mounted, at least by way of its support posts 42 , to the row of barrier blocks 98 and not into the ground 16 . The tower base 84 ′ in this embodiment is a concrete block, and the tower base 84 ′ or tower structure 82 may or may not be mechanically tied to the row of blocks 98 , for example by way of a tie-bar (not shown) attached to and extending between the row of blocks 98 and either the tower base 84 ′ or the tower structure 82 .
FIG. 7 shows a perspective view of a portion of a third embodiment of an intrusion delaying barrier 10 ″ equipped with a variety of sensors 50 ′, 52 , 54 , 56 , 64 , 66 , 66 ′, 68 , 70 , and 72 , and revealing a pass-through opening 18 . Unlike the first and second embodiments 10 and 10 ′, this third embodiment of an intrusion delaying barrier 10 ″ has a screen fence mounted by support posts 42 into the ground 16 rather than being mounted instead to an accompanying Normandy type of barrier or row of concrete blocks. There is no barrier continuity sensor 90 . The seismic sensor 66 ′ is shown mounted to the base of the support pole 42 . A vibration sensor 50 ′ is mounted to the screen 44 of the screen fence 40 . The tower base 84 ′ is concrete, and the tower structure 82 or tower base 84 may or may not be connected directly to the screen fence 40 , as for example by means of a tie-bar (not shown). This embodiment is less expensive than the previously described embodiments, but it lacks the added physical protection of a harder barrier structure; however this embodiment does still afford having multiple sensors and multiple types of sensors all interconnected structurally.
FIG. 8 shows a diagram 100 depicting sensors and computers of neighboring sections 102 and 102 ′ of intrusion delaying barrier according to at least one implementation of the current invention(s). The physical sections 110 and 110 ′ of sections 102 and 102 ′ are shown joined to one another forming a barrier row. Sensors 120 , 130 , 140 , 150 (two instances), and 150 ′ are shown associated with the physical section 110 ; sensors 120 , 130 , 140 , and 150 ′ are electronically linked to a computer 160 on the physical section 110 (e.g. each by a link 106 such as shown between sensor 150 ′ and computer 160 ). Sensors 150 (two instances) are electronically linked to sensor 150 ′ by a link such as link 105 . Similarly: sensors 120 ′, 130 ′, 140 ′, 150 ″ (two instances), and 150 ′″ are shown associated with the physical section 110 ′; sensors 120 ′, 130 ′, 140 ′, and 150 ′″ are electronically linked to a computer 160 ′ on the physical section 110 ′; sensors 150 ″ (two instances) are electronically linked to sensor 150 ′″. The computers 160 and 160 ′ are in turn electronically linked to another computer 170 remote from computers 160 and 160 ′ (e.g. by link 107 between computer 160 and computer 170 ). The remote computer 170 is shown optionally linked electronically (e.g. by link 108 ) to at least one other computer or alarm device or alarm annunciator 180 . The straight lines in the diagram representing electronic links between sensors, between sensors and computers, and from one computer to another, represent any imaginable means of communication that one skilled in the art might choose to implement for this context, such as by use of communication cables, radio links, and/or the Internet. The computers 160 and 160 ′ could also be connected to communicate with one another. The ends of outwardly adjacent sections of the common barrier row are also shown on the left and right hand ends of the joined two sections 102 and 102 ′ combination. The physical sections 110 and 110 ′ of sections 102 and 102 ′ can, for example, be representative of those shown in FIGS. 1 , 2 , 6 , and 7 ; and the sensors of FIG. 8 can be representative of sensors shown in those same figures. In FIGS. 1 , 2 , 6 , and 7 , the computers 160 , 160 ′, 170 , and optionally 180 are hidden from view along with power devices and any cabling for communication between the sensors and computers.
FIG. 9 shows one embodiment of a sensor subsystem 300 that communicates with a computer 200 . In some implementations of the current invention(s), any of the sensors described in the previous figures could be configured as sensor subsystem 300 . And in some implementations of the current invention(s), any of the computers 160 , 160 ′, 170 , and 180 of FIG. 8 can be configured as computer 200 . In one implementation of the invention(s), sensor subsystem 300 is computer 160 as shown in FIG. 8 , computer 200 is computer 170 as shown in FIG. 8 , and the link between them is electronic link 107 also shown in FIG. 8 . But depending upon the implementation, the electronic link between sensor subsystem 300 and computer 200 can be any of the links 105 - 108 shown in FIG. 8 . Both the sensor subsystem 300 and the computer 200 are shown with connections to the Internet 230 and/or radio communication equipment 240 , but this is optional and may not be needed in many embodiments. Power supplies 260 and 260 ′ are shown, showing their connections to some of the components, but it should be understood by those skilled in the art that this is not meant to limit the embodiments of the present invention(s) since power and its routing to components within the computer 200 and sensor subsystem 300 can be accomplished in many ways not shown. The computer 200 includes a computer processor shown as computer engine 210 . Connected to the computer engine 210 may be program memory 212 , data storage memory 214 , a user interface 216 , one or more communications interfaces 218 , a connection to the Internet 230 , an RF transceiver 240 , other devices 250 , and at least one connection to at least one alarm 270 . This alarm 270 is meant to represent either an actual alarm device or simply a memory device maintaining one or more alarm status indicator values, wherein such a memory device can, for example, be part of data storage memory 214 or a memory register of the computing engine 210 . As computer 200 represents a general purpose computer, nothing in this block diagram should be taken to limit the computer architecture or function of computers used to generate alarm signals or alarm status values in the current invention(s). Some embodiments of the current invention(s) can store one or more machine learning algorithms in the program memory 212 for execution by the computer engine 210 to maintain at least one alarm status indicator value in the data storage memory, and to generate signals to the alarm 270 based on results of a pattern detection and/or recognition results discovered within data received from one or more sensors such as the sensor subsystem 300 . The signals sent to the alarm 270 would relate to the presence or absence of intrusion activities on a barrier as sensed by the sensor subsystem(s) 300 .
Within FIG. 9 , the sensor subsystem 300 represents only one possible configuration for a sensor subsystem or sensor. What is shown is a general purpose computing apparatus. One skilled in the art can understand the generalities of what is shown in FIG. 9 , and that sensors and computer embodiments of the current invention(s) aren't intended to be limited by what is shown in FIG. 9 . Regarding the sensor subsystem 300 shown, in some embodiments the sensor transducer 222 might represent multiple sensor transducers. A user interface 216 ′ might or might not be used or incorporated. Some sensor transducers might be connected directly to another computer (such as the computer 200 ) making all of the parts shown in the sensor subsystem 300 unnecessary other than the sensor transducer 222 itself.
FIG. 10 shows a pictorial depiction of the computerized sensor subsystem 300 diagramed within FIG. 9 . Added in this view are an enclosure 320 for most of the sensor subsystem's components, a power supply enclosure 350 , an RF antenna 360 , a sensor transducer module 310 , a display and control devices of a human interface 330 , and communications cabling 340 . Whereas what is depicted here is very generic, it is not to be taken as limiting the forms and functions of actual sensors and sensor subsystems as can be used in embodiments of the current invention(s).
FIG. 11 shows a pictorial depiction of a compact embodiment 300 ′ of a sensor transducer or sensor subsystem 310 ′. What is shown is a sensor module 310 ′ with a portion of its communications cable or other connection medium 340 ′ extending out of a side of the module 310 ′. The medium 340 ′ could represent a wireless link to a remote receiver or transceiver.
FIG. 12 shows one representation of one embodiment of one form of learning machine that might be practiced in implementing some of the embodiments of the current invention(s). Such learning machines would be processed by any of the computers 200 or 300 , or any of the computing engines 210 or 210 ′, shown in FIG. 9 , which is to say they could be processed by any of the computers 160 , 160 ′, 170 , and/or 180 shown in FIG. 8 . What is shown in FIG. 12 is an example of an artificial neural network 400 ) having a particular structure, but other structures would also fall within the scope of the current invention(s) and claims. These other structures might, for example, have fewer or more inputs and/or outputs, fewer or more nodes within the hidden layers, and/or recurrent connections. This artificial neural network 400 has four layers 410 , 420 , 430 , and 440 shown in four respective columns arranged from left to right respectively. At “layer 1” 410 , the input layer, there are six input values x 0 through x 5 , where x 0 at the top row of its column represents an input value that has a constant value of unity. Inputs x 1 through x 5 represent input values from sensors and are ordered sequentially down the column into lower row positions. These input values x 1 through x 5 may include data samples taken at different times from a single sensor, samples taken from multiple sensors taken at the same time, samples taken from different types of sensors, and/or samples taken from multiple sensors that are of the same type. In “layer 2” 420 (first hidden layer), there are five nodes (simulated neurons) that output activation values a 2 0 through a 2 4 , where a 2 0 represents an output value of unity. In “layer 3” 430 (second hidden layer), there are five nodes (simulated neurons) that output activation values a 3 0 through a 3 4 , where a 3 0 represents an output value of unity. In “layer 4” 440 (output layer), there are two output nodes (simulated neurons) that output activation values a 4 , and a 4 2 which are also called h θ (x) 1 and h θ (x) 2 respectively, where the “h” stands for “hypothesis value”. As we will see in the descriptions of FIGS. 13 and 15 below, the theta subscripts mean that the hypothesis values, i.e. the output values of the network, are a function of a matrix of theta values representing parameters learned by the network. As with layer 1 for input values, the activation values of the “neurons” in the other layers are all arranged in each column such that their subscript index values increase with each lower row position relative to the top of the respective column. Such arrangement, we will recognize in FIG. 15 , is convenient for arranging matrices and vectors of these values for use in the linear algebra used for efficient representation of the mathematics involved in an artificial neural network. Note that the superscripts to the activation symbols denote the number of the layer they are in. Some embodiments of the current invention(s) can employ artificial neural networks, and these artificial neural networks are processed on computers such as those within the computer engines 210 and/or 210 ′ shown in FIG. 9 . Also shown in FIG. 12 are lines connecting each node in each column to all of the nodes in the subsequent layer with the exception of those having zero-subscripted activation values (those with a constant unity output value). To avoid cluttering the diagram further with callout numbers, callouts to the nodes and lines interconnecting the nodes of adjacent columns are reduced to just those to the nodes 412 , 422 , 432 , and 442 at the tops of each column respectively, and to just the interconnection lines 414 , 424 , 434 that interconnect the top most nodes from one column to the next respectively, going from the first layer to the fourth layer.
FIG. 13 shows a two-step process embodiment 500 of simulating neuron activation in each layer of an artificial neural network. In the first step 510 and for the second layer, variable “z (2) ” is a vector of values calculated as the product of the transpose of a matrix θ (1) of parameter values for the first layer and a vector “x” of input values. The symbol “T” in the figure stands for the transpose operator. In the first step 510 and for the subsequent j'th layers, variable)“z (j) ” is a vector of values calculated as the product of the transpose of a matrix θ (j-1) of parameter values for the “j−1”th layer and a vector “a (j-1) ” of activation values of that preceding layer (i.e. of the “j−1”th layer). In the second step 520 , activation values a(z) are calculated as a function of z using the logistic function g(z) which is also called a sigmoid function. One skilled in the art of artificial neural networks will recognize that other choices exist for activation functions without deviating from the scope of the current invention(s).
FIG. 14 shows an embodiment 550 of a cost function for an artificial neural network, and it will be familiar to those skilled in the art of artificial neural networks. It represents the error of an artificial neural network computed on a set of test data x (m) , where there are M vectors or sets of sensor input data for which a true classification result y (m) is known for each vector x (m) , where the value of the index m runs from 1 to M. The cost function of this embodiment is the function J(θ), and its first of two terms is computed as an arithmetic average taken over the M input vectors x (m) of the test set, where each vector corresponds to a single set of sensor samples. What is being averaged is a sum taken over the K activations of K neurons at the output of the network having K outputs. The sum is of a function of the actual outputs h θ (x (m) ) k and the known true classification values y k (m) recorded for the test data. The second term of the cost function is a regularization term used to control overfitting the data according to the value selected for the positive-valued parameter λ. Each quantity θ ij (l) is the weighting parameter used to calculate an activation value (see FIGS. 13 and 15 ) for the j'th neuron (or node) in the (l+1)'th layer from the i'th neuron in the l'th layer. As one skilled in the art of artificial neural networks will understand, it is by obtaining optimal values for these elements of the θ matrix that a minimum can be obtained for the cost value J(θ), thereby enabling the output(s) h θ (x) of an artificial neural network to match as many correct classification values as possible given the quality of the test data used to find the best values for θ.
FIG. 15 shows more detail of the first of the two steps shown in FIG. 13 used in computations of simulated neuron activations. Equation 600 expresses multiplication of the vector of x input values (sensor output values) by the transpose of the theta matrix for theta values going from the first layer to the second layer. Equation 610 expresses multiplication of the vector of a 2 activation values from the second layer by the transpose of the theta matrix for theta values going from the second layer to the third layer. Equation 620 expresses multiplication of the vector of a 3 activation values from the third layer by the transpose of the theta matrix for theta values going from the third layer to the fourth and last layer, i.e. the output layer.
FIG. 16 shows some of the computational steps 700 used in an embodiment of backward propagation used to seek a minimum of the cost function shown in FIG. 14 . In order to seek a minimum in J(θ), its derivatives with respect to the theta values are used. The formulae used to calculate these derivatives are given in this figure and should be familiar to those skilled in the art of artificial neural nets and the use of backward propagation and gradient descent methods. One such method is described in the next paragraph describing FIG. 17 .
FIG. 17 shows steps 810 , 820 , 830 , 840 , 850 , 860 , 870 , and 880 in an embodiment of a method 800 for creating and teaching an artificial neural net such as shown in FIG. 12 . This method enables the finding of optimal values to use for the theta values of an artificial neural network such as used in some of the embodiments of the current invention(s). The result of applying the method is a set of theta values that perform optimally at least on the training and cross-validation data sets used in the training process. Desirable error metrics to compute for each output node or neuron include the following: Probability of detection P d , Precision P, Recall R, and F1 score where F1=2PR/(P+R). Precision is calculated by dividing the number of input vectors that are classified correctly as positives by the number of input vectors that are classified correctly or incorrectly as positive. Recall is calculated by dividing the number of true positives by the number of input vectors that should have been classified as positive. One aspect of the current inventions is to have an additional method step that records true classification values y k (M+n) obtained from human observations for n vectors of input sensor data x (M+n) , where M+n represents an index value for data taken at least after the M vectors of training data. Using this additional data, the theta values of the network can be retrained with a larger and larger data set as more data is collected. As one skilled in the art of artificial neural networks understands, training an artificial neural network with a larger quantity of accurately classified input vectors will almost always generate more optimal values for theta (i.e. for the matrix θ).
It is intended that one skilled in the art of artificial neural networks can readily envision fewer or more steps relative to those in the process 800 shown in FIG. 17 , but it is intended that these modifications are within the scope of the present invention(s). The embodiments described and illustrated in this disclosure focus for simplicity on artificial neural networks, but it is also intended that any of the other techniques within the broader field of pattern detection and recognition known as learning machines could be used and still be within the scope of this disclosure and of the current invention(s). A particular example of one of these other techniques is the use of Support Vector Machines that use kernel functions (such as a Gaussian kernel, or even a sigmoid function, at feature points) to achieve the biggest possible distance margin between opposite classes within a high-dimension feature space. Although machine learning avoids explicit programming of expert knowledge and logic rules, some embodiments of the present invention(s) can utilize a hybrid collection and/or mixture of these other techniques. Furthermore, some embodiments of the present invention(s) can include more than a single artificial neural network or other learning machine. For example, some sensors that are used can have their own simulated artificial neural networks operating within their own sensor subsystems. And segments of barrier length can include one or more learning machines operating independently of other segments of barrier length. Furthermore, some embodiments of the present invention(s) can include remote access and adjustment of machine learning processes and/or learning results, as for example by way of a remote computer and one or more Internet connections between the remote computer and a security barrier, e.g. to an intrusion delaying barrier of the current invention(s).
Several embodiments are specifically illustrated and/or described herein, and these illustrations are not meant to be restrictive. It will be appreciated that modifications and variations, as well as combinations of the above embodiments, and other embodiments not specifically described herein, are covered by the above teachings and are within the scope of the appended claims without departing from the spirit and intended scope thereof. Any arrangement configured to achieve the same purpose may be substituted for the specific embodiments shown. Method steps described herein may be performed in alternative orders. Various embodiments of the invention include programs and/or program logic stored on non-transitory, tangible computer readable media of any kind (e.g. optical discs, magnetic discs, semiconductor memory). System structures and organizations described herein may be rearranged. Various embodiments of the invention can include interconnections of various types between various numbers of various subsystems and sub-components. The scope of various embodiments of the invention includes any other applications in which the above structures and methods are used. | An intrusion delaying barrier includes primary and secondary physical structures and can be instrumented with multiple sensors incorporated into an electronic monitoring and alarm system. Such an instrumented intrusion delaying barrier may be used as a perimeter intrusion defense and assessment system (PIDAS). Problems with not providing effective delay to breaches by intentional intruders and/or terrorists who would otherwise evade detection are solved by attaching the secondary structures to the primary structure, and attaching at least some of the sensors to the secondary structures. By having multiple sensors of various types physically interconnected serves to enable sensors on different parts of the overall structure to respond to common disturbances and thereby provide effective corroboration that a disturbance is not merely a nuisance or false alarm. Use of a machine learning network such as a neural network exploits such corroboration. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT
Not Applicable.
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC
Not Applicable.
BACKGROUND OF THE INVENTION
Technical Field
The present invention relates to an odor-eliminating apparatus. More specifically, an embodiment of the present invention involves a toilet ventilation exhaust system that employs a dedicated, internal, orificial, annular vent passage integral to the upper rim of the toilet bowl. When connected to an appropriate exhaust line and vent exhaust fan, this system effectively and efficiently eliminates toilet odors. This invention functions during normal operation and offers provisions for recovery from upset conditions of condensate buildup and overflow as well as for periodic maintenance if vent exhaust path clogging ever were to occur.
Current art toilets depend on a ceiling ventilation exhaust fan to remove bathroom odors which originate in the toilet. Many of the more noxious gases are considerably heavier than air so a prolonged ventilation period using the ceiling exhaust fan method is necessary to exhaust toilet odors. This process is inefficient and ineffective as the gases must exit the toilet and enter the room air space before being exhausted. This non-direct exhaust flow path makes the odorous gases susceptible to mixing with other air and to being carried into areas outside the toilet room, thus causing the exhaust fan to operate for an extended period of time to remove all odors and often ineffectively. Since current art ceiling exhaust fans generally operate at 1.42-3.12 cubic meters per minute (50-110 cubic feet minute), literally scores of cubic meters (hundreds or thousands of cubic feet) of air are removed by prolonged operation of the fan before the toilet odors are eliminated from the toilet and surrounding air space. This air generally is conditioned (i.e., heated or cooled), and continued exhaust flow will result in pulling more outside, unconditioned air into the home or building. Sustained exhaust fan operation and the need to condition excessive replacement air cause unnecessary operation of building exhaust and heating, ventilating, and air conditioning systems, thus demanding unnecessary energy consumption when compared to the proposed invention. Additionally, the current art exhaust fans often include a light which is energized when the exhaust fan is energized using the same on/off switch. Daytime use of the light may be an additional waste of energy.
Some have attempted to address the problem by employing the use of the existing rim jet ports for gaseous odor removal. Sharing of common vent/flow ports for both noxious air exhaust and flushing water would require cycling of the exhaust fan to reestablish the exhaust flow after flushing. Otherwise, the continuing ventilation exhaust flow will establish and maintain a small standing column of water in the vent/flow ports equal in height (in millimeters or inches) to the suction pressure of the exhaust fan and will prevent subsequent exhaust air flow. During this period there will be no further exhaust flow from the toilet, and noxious odors will escape from the toilet and into the surrounding area. This cycling of exhaust fan operation to eliminate this concern makes such arrangements in a single residence inconvenient. It is impractical or unworkable for such arrangements in a larger building with multiple toilets and a common exhaust ventilation system which cannot be cycled off then on after every individual flush. Additionally, using the same rim jet holes for both water and air flows will result in cyclical wetting and drying of the small diameter ports. This ultimately will clog these ports due to normal presence of soluble solids in the water. In such cases neither the flush water flow nor exhaust air flow will be maintained without frequent maintenance to keep the rim jet ports clear. This is not a workable approach to toilet operation or odor removal. Therefore, an aspect of the present invention which provides for a separate flow path for water introduction into the toilet bowl and a separate flow path for odor removal is necessary to maintain reliable and efficient toilet operation for both flushing and odor removal.
The toilet system of U.S. Pat. No. 5,727,263 discloses two separate flow paths with two separate exhaust fans, each servicing a separate exhaust path. In the event of toilet overflow or condensate buildup in the exhaust path, the fan motors, which are below toilet bowl level, would fail due to water intake and would require replacement. There is no design provision for drainage of condensate or overflow liquid on the upstream or downstream side of each exhaust fan. There is no provision for performing maintenance which may require unclogging or removing water in the vent exhaust path or performing other required cleaning of the vent exhaust path which may occur over time. There is no specified consideration for factors of vent exhaust orifice sizing, exhaust ventilation piping size, vent exhaust flow rate, or capillary action relating to fan performance capabilities.
The toilet system of U.S. Pat. No. 5,809,581 discloses a system without toilet overflow or condensate buildup remedies. There is no recovery of the system due to overflow or condensate buildup without excavating the floor to remove the liquid filled exhaust piping which slopes downward from the toilet rim and is buried into the floor below the toilet. This resulting water column would block vent exhaust air flow, deprive the exhaust fan of air flow and cause exhaust fan failure and loss of vent exhaust flow. Consistent with the first deficiency, there is no element for draining any part of the vent exhaust path. There is no element for performing maintenance which may require unclogging of the vent exhaust path or performing other required cleaning of the exhaust pathway which may occur over time. There is no teaching of vent exhaust orifice sizing, exhaust ventilation piping size, vent exhaust flow rate, or capillary action relating to fan performance capabilities. There is no stated consideration for location of the exhaust fan with respect to concern for condensate buildup or toilet overflow condition. Drawings show the vent exhaust orifices smaller than the liquid rim jet flush orifices. While the drawings are not stated to be to scale, the air vent holes would be larger than the liquid rim jet orifices to achieve adequate air flow and avoid capillary action concerns.
U.S. Pat. No. 7,331,066 discloses a toilet system with a non-collapsible, flexible, hollow tube running throughout the upper rim duct in contrast to the wholly integrated but separate casting of the annular exhaust passage described herein. The flexible, hollow tube running throughout the upper rim duct of U.S. Pat. No. 7,331,066 would reduce the otherwise available cross-sectional area of the liquid, upper rim duct, create turbulence, and impede liquid flow through the upper rim duct. The airflow means/air exhaust mechanism disclosed in U.S. Pat. No. 7,331,066 can be any selection of suction blower, vacuum pump, or exhaust fan. Also, a high pressure suction created by a vacuum pump or suction blower would exacerbate orifice clogging, jeopardize the function of the air exhaust mechanism due to the possibility of pulling water into these mechanisms with condensate buildup or toilet overflow, and would exacerbate efforts to perform effective back flushing of the vent exhaust passageways due to high suction pressures pulling in possible contaminants into the vent exhaust orifices. Some aspects of these concerns could be mitigated by the pressure switch which would turn off the exhaust mechanism when the user leaves the toilet, but upon subsequent usage of the toilet, failure of the system to function would be likely. There is no element for maintenance back flushing or cleaning. This connection between the vent exhaust orifices and the non-collapsible, flexible, hollow tube is a very restrictive flow path to the flexible, hollow tube and makes questionable the ability to provide adequate exhaust air flow. There is no provision to accommodate condensate buildup or toilet overflow. This could result in fan (or other exhaust mechanism) failure and cessation of function of the vent exhaust system. There is no consideration of capillary action. Capillary action could be significant due to the very restrictive flow paths shown between the vent exhaust orifices and the non-collapsible, flexible, hollow tube.
All of the aforementioned systems suffer from the same deficiency of permitting condensate or overflow conditions into the vent pathway whereby the water would block the evacuation of the fumes in the pathway.
The references do not address the upset conditions of condensate buildup or of toilet overflow which subsequently may render many of the other known systems to be non-functional. An embodiment of the present invention provides for features which would allow recovery without equipment damage from toilet overflow and condensate buildup. Embodiments of the present invention also permit maintenance back flushing to clear the annular vent passage, vent exhaust orifices, annular exhaust vent line, and parent exhaust line if clogging of the exhaust ventilation flow path were to occur for any reason over the lifetime of operation.
BRIEF SUMMARY OF THE INVENTION
One embodiment of the present invention provides a toilet system comprising a toilet bowl having a rim jet annulus located circumferentially inside a portion of a rim disposed above and around the periphery of the toilet bowl wherein the rim jet annulus has a plurality of rim jet orifices for introducing water into the toilet bowl. An annular vent passage which is separate from the rim jet annulus is located circumferentially inside and concentric with the rim jet annulus of the toilet rim of the toilet bowl. The annular vent passage has a plurality of vent exhaust orifices located at the inner radius of the annular vent passage and positioned above the rim jet orifices to avoid communication of the water from the rim jet orifices into the annular vent passage via the vent exhaust orifices. According to another embodiment, the annular vent passage is predominantly located above the existing rim jet annulus. In either embodiment, the annular vent passage connects to an annular exhaust vent line at the back vertical plane of the toilet bowl to avoid interference with the rim jet annulus. The annular exhaust vent line slopes downward from the back vertical plane of the toilet bowl to a low point where there is located a low point drain line and a low point drain valve at the bottom of the low point drain line. The annular exhaust vent line continues with a constant slope upward for a distance to join with an enlarged parent exhaust line. The parent exhaust line is in communication with a bypass branch line upstream of a vent exhaust fan upstream isolation valve located upstream of a vent exhaust fan and the parent exhaust line. The annular exhaust vent line may exit the toilet bowl at a same elevation as the annular vent passage or may exit the toilet bowl below the toilet rim from inside the toilet bowl to avoid interference with the rim jet annulus flow path. For example, the vent exhaust orifices are sized in consideration for vent exhaust flow and capillary action consistent with the vent exhaust fan.
In a further embodiment, the bypass branch line tees off the parent exhaust line upstream of the vent exhaust fan upstream isolation valve and at a minimum elevation more than the sum elevations of the toilet rim plus the maximum suction pressure of the vent exhaust fan. Alternatively, the bypass branch line further comprises a branch line isolation/throttle valve which may be used for throttling of air flow or for throttling or isolating liquid flow for maintenance back flush operations. In yet another embodiment, the bypass branch line does not include a branch line isolation/throttle valve. The bypass branch line is sized to allow sufficient and continuous ventilation flow for the vent exhaust fan under normal and upset conditions to maintain exhaust flow through the vent exhaust orifices with the bypass flow and to serve as a maintenance access connection for back flushing the parent exhaust line, annular vent passage, and vent exhaust orifices.
In one embodiment, a single fan is used with a system as described herein to create a suction at the plurality of vent exhaust orifices of the annular vent passage of the toilet when one or more toilets are connected to the same parent exhaust line.
According to one embodiment, the upward slope of the annular exhaust vent line and parent exhaust line of a system as describe herein is at least 3 millimeters per 0.3 meters of piping from the low point drain line.
According to another embodiment, the low point drain line located at the low point of the annular exhaust vent line of the system described extends to a length which is greater than the height of the water column equivalent to the maximum suction pressure possible from the vent exhaust fan to ensure positive drainage under all use conditions, and the low point drain line and the low point drain valve at the end of the low point drain line have an internal diameter which is greater than the diameter of any vent exhaust orifice.
Another embodiment of a toilet system comprises a toilet bowl having a rim jet annulus located circumferentially inside a portion of a rim disposed above and around the periphery of the toilet bowl wherein the rim jet annulus has a plurality of rim jet orifices for introducing water into the toilet bowl. An annular vent passage is located through a portion of a circumference of the toilet bowl rim and is separate from but circumferentially inside and concentric with the rim jet annulus such that the annular vent passage has a plurality of vent exhaust orifices located at the inner radius of the annular vent passage and above the outer, annular rim jet orifices to avoid communication of water from the plurality of rim jet orifices to the plurality of vent exhaust orifices. The annular vent passage exits the toilet at the back vertical plane of the toilet bowl at an annular exhaust vent line to avoid interference with a water rim jet annulus flow path. The annular exhaust vent line slopes downward from the rear vertical plane of the toilet bowl, and deliberately creates a low point drain location, having a low point drain line tee from the low point drain location of the annular exhaust vent line which extends from the low point drain location to a length which is greater than a water column equivalent to the maximum suction pressure of a vent exhaust fan to ensure positive drainage under all conditions during normal operation, recovery from toilet overflow, and upon completion of back flushing activities. The annular exhaust vent line continues on an upward slope of at least 3 millimeters per 0.3 meter of piping to the rear vertical plane of the toilet where the vent exhaust line is enlarged to continue as a parent exhaust line which is in communication with a bypass branch line upstream of a vent exhaust fan upstream isolation valve located upstream of the vent exhaust fan and the parent exhaust line outlet. The low point drain line and the low point drain valve at the end of the low point drain line have an internal diameter which is greater than the diameter of any vent exhaust orifice. For example the vent exhaust fan of this embodiment is located in the remainder of the parent exhaust line at a minimum elevation greater than a sum elevation of the elevation of the toilet bowl rim plus the maximum suction pressure of the vent exhaust fan, and has a vent exhaust fan upstream isolation valve selected for minimum resistance to ventilation air flow and is located upstream of the vent exhaust fan and wherein the vent exhaust fan is capable of overcoming a capillary effect which may occur after water intrusion into the plurality of vent exhaust orifices, and is of sufficient suction pressure and flow capability to establish desired vent exhaust flow rate through the plurality of vent exhaust orifices even with air flow through the bypass branch line.
In one embodiment, the bypass branch line can be added at the elevation greater than the sum of the elevation of toilet rim plus the maximum suction pressure of the vent exhaust fan, and wherein the bypass branch line tees into the parent exhaust line upstream of the vent exhaust fan upstream isolation valve, and is sized to allow sufficient, continuous ventilation flow for the vent exhaust fan operation under both normal conditions and upset conditions of a toilet overflow or condensate condition blocking ventilation exhaust air flow through the annular vent passage, and is with or without an installed branch line isolation/throttle valve selected to ensure necessary air flow through the vent exhaust fan, and serves as a maintenance connection for back flushing the annular vent passage, vent exhaust orifices, annular exhaust vent line, or parent exhaust line in the event of vent path clogging.
In yet another embodiment a method of venting an odor within a toilet system is provided. An odor within a toilet bowl is vented through a plurality of vent exhaust orifices of an annular vent passage of the toilet bowl. The toilet bowl includes a rim jet annulus located circumferentially inside a portion of a rim disposed above and around the periphery of said toilet bowl wherein the rim jet annulus has a plurality of rim jet orifices for introducing water into the toilet bowl. An annular vent passage which is separate but located circumferentially inside the rim jet annulus of the toilet rim of the toilet bowl. The annular vent passage having the plurality of vent exhaust orifices located at the inner radius of the annular vent passage and positioned above the rim jet orifices to avoid communication of the water from the rim jet orifices into the annular vent passage via the vent exhaust orifices. The annular vent passage connects to an annular exhaust vent line at the back vertical plane of the toilet bowl to avoid interference with the rim jet annulus. The annular exhaust vent line slopes downward from the back vertical plane of the toilet bowl to a low point where there is located a low point drain line and a low point drain valve at the bottom of the low point drain line. From this point, the annular exhaust vent line continues with a constant slope upward for a distance to join with a parent exhaust line wherein the parent exhaust line is in communication with a bypass branch line and a vent exhaust fan upstream isolation valve located upstream of a vent exhaust fan and the parent exhaust line outlet wherein the annular exhaust vent line, the parent exhaust line, the bypass branch line, the exhaust fan upstream isolation valve and vent exhaust fan are above ground. The odor is evacuated through the annular exhaust vent line with the aid of the vent exhaust fan when the fan is creating a suction at the plurality of exhaust orifices of the annular vent passage. In another embodiment a single fan is used to create a suction at the plurality of vent exhaust orifices of the annular vent passage of the toilet when one or more toilets are connected to the same parent exhaust line.
The operation of an embodiment of the present invention under normal conditions of use will be transparent to the user, only requiring exhaust fan operation consistent with current exhaust fan control art. However, an embodiment also accommodates the condition of toilet overflow and condensate buildup anywhere in the vent exhaust path while allowing recovery without equipment damage. Further, embodiments of the invention provide for as-needed maintenance to back flush any portion of the exhaust system in the event of system clogging. The system and method may be applied to a single toilet and exhaust fan or to multiple connected toilets with interconnected vent lines to a common exhaust fan. It is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
The vent exhaust path may be considered the ventilation flow path comprising the annular vent passage, vent exhaust orifices, annular exhaust vent line, parent exhaust line, including in-line components or any part of this path not otherwise specifically designated. The ventilation flow path communicates fumes from the toilet bowl to a location other than the room where the toilet bowl is located.
Embodiments of the present invention include a toilet having an inner annular vent passage which runs through a portion of the circumference of the toilet bowl rim. The annular vent passage is separate but concentric with the current art liquid flush rim jet annulus such that the vent exhaust orifices are located inside and above the outer, annular rim jet orifices to avoid communication between the vent exhaust orifices of the upper annular vent passage and the liquid rim jet orifices. The annular vent passage is formed integral to the toilet bowl rim and is not therefore flexible. The annular exhaust vent line serves as the annular vent passage exit flow path as the line exits the toilet, and it exits the toilet bowl to avoid interference with the water rim jet annulus flow path. The annular exhaust vent line slopes downward from the toilet bowl rim and deliberately creates a low point drain location. At the low point drain location of the annular exhaust vent line, there is located a low point drain line. The low point drain line extends from this low point to a length which is greater than the water column equivalent to the maximum suction pressure of the vent exhaust fan to ensure positive drainage under all conditions. A low point drain valve is located at the end of the low point drain line and, when open, permits drainage of liquid from condensate buildup during normal operation, upon recovery from a toilet overflow, and upon completion of back flushing operations of the vent exhaust flow path. The annular exhaust vent line continues on an upward slope from the low point to the back vertical plane of the toilet where it would be enlarged to continue as the parent exhaust line.
Embodiments of the present invention include a dedicated vent exhaust fan which is located at a minimum level above the sum elevations of toilet rim plus the maximum suction pressure of the exhaust fan. Upstream of the vent exhaust fan is located a vent exhaust fan upstream isolation valve which will be a gate or ball valve to minimize resistance to flow. If the vent exhaust fan is located at an elevation that will prevent water intrusion during a back flush maintenance activity, an upstream isolation valve may not be necessary. The vent exhaust fan must be capable of overcoming any effect from capillary action which may occur after water intrusion into the annular vent passage and be capable of sufficient flow capability to provide desired vent exhaust flow rate.
An embodiment of the present invention includes a bypass branch line which is upstream of the dedicated vent exhaust fan and upstream of the vent exhaust fan upstream isolation valve (if installed). The bypass branch line must be installed at an elevation greater than the sum of the toilet rim elevation and the maximum suction pressure of the vent exhaust fan. The bypass branch line is sized to allow sufficient, continuous ventilation flow for reliable vent exhaust fan operation even with toilet overflow or condensate condition blocking ventilation exhaust air flow. The bypass branch line may have installed a branch line isolation/throttle valve (globe valve or similar to allow effective throttling) to ensure vent exhaust fan flow under all conditions. The bypass branch line serves as a maintenance connection for back flushing the vent exhaust path if clogging ever were to occur.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more preferred embodiments of the invention and are not to be construed as limiting the invention. In the drawings:
FIG. 1A and FIG. 1B illustrate cross sectional views of the toilet rim according to embodiments of the present invention.
FIG. 2 is a top view of the toilet bowl rim according to one embodiment illustrating the relative numbers and locations of the current art rim jet orifices and the proposed vent exhaust orifices of the present invention.
FIG. 3A and FIG. 3B illustrate two different embodiments of the complete toilet/exhaust system present invention.
FIG. 4A and FIG. 4B illustrate two embodiments of the utility box configurations housing the bypass branch line and other components.
FIG. 5 is a view of the toilet exhaust system according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As used herein “a” or “an” or “the” means one or more.
Referring now to FIGS. 1A and 1B , FIGS. 1A and 1B depict cross-section views of the toilet bowl rim 103 according to two embodiments of the present invention. In FIG. 1A the vent exhaust orifices 105 of the ventilation exhaust path are located in the inner radius of the annular vent passage 111 which is circumferentially inside the rim jet annulus 113 , and the vent exhaust orifices 105 are located above the existing rim jet orifices 107 of the rim jet annulus 113 to avoid water intrusion during normal operation. In FIG. 1B the vent exhaust orifices 105 of the ventilation exhaust path are located in the inner radius of the annular vent passage 111 which is concentric with but predominantly above the rim jet annulus 113 , and the vent exhaust orifices 105 are located above the existing rim jet orifices 107 of the rim jet annulus 113 to avoid water intrusion during normal operation. In the FIG. 1B embodiment, the outer, circumferential wall of the annular vent passage shares the toilet bowl wall with the rim jet annulus at the rim of the toilet bowl. These vent exhaust orifices 105 are in communication with the balance of the ventilation exhaust path (i.e., annular vent passage, annular exhaust vent line, and parent exhaust line). Wall thickness for each toilet bowl wall of any embodiment of this invention would continue to be similar to the current art to ensure structural integrity during normal use but is not limited thereto as the system could work with custom toilets having non-traditional toilet bowl wall thickness.
Referring now to FIG. 2 , a plan view embodiment of the toilet bowl rim 203 showing the relative number and location of the existing rim jet orifices 205 and the vent exhaust orifices 207 according to one embodiment of the present invention is illustrated. The size and number of the vent exhaust orifices may vary, depending on the suction pressure capability of the vent exhaust fan and desired vent exhaust flow rate. Cross section 1 A of the toilet bowl rim is illustrated in FIG. 1A with an alternate embodiment illustrated in FIG. 1B .
Referring now to FIGS. 3A and 3B (associated with FIGS. 1A and 1B , respectively) show side view embodiments of the toilet 300 with the location of the annular exhaust vent line 315 leading from the annular vent passage 111 upon exiting at the back vertical plane 316 of the toilet bowl 301 and molded into the toilet body and connecting to the parent exhaust line 305 . The low point drain line 307 , low point drain valve 310 , and the constant slope upward of the annular exhaust vent line from the low point to the back vertical plane 317 of the toilet are illustrated. The exhaust path is illustrated by the dotted arrows. The vent exhaust fan 313 is positioned between the parent exhaust line outlet 309 and the vent exhaust fan upstream isolation valve 314 . The vent exhaust fan upstream isolation valve is a valve which offers little head loss (e.g., ball valve or gate valve). Further upstream of the vent exhaust fan upstream isolation valve is located a bypass branch line 311 which tees off the parent exhaust line 305 at a minimum elevation greater than the sum of the elevation of the toilet rim plus the maximum suction pressure of the vent exhaust fan. In the bypass branch line is a branch line isolation/throttle valve 312 (e.g., globe valve) which may be used for throttling of air flow or for throttling or isolating liquid flow for maintenance back flush operations. The branch line isolation/throttle valve may be present in either embodiment described in FIGS. 1A and 1B . The manner in which the annular exhaust vent line exits the toilet bowl rim in the system may vary in the two embodiments. In FIG. 3A , the embodiment of the annular exhaust vent line exits the toilet bowl rim below the toilet rim from inside the bowl at position 304 . In FIG. 3B , the embodiment of the annular exhaust vent line exits the upper part of the toilet rim outside of the toilet bowl 301 and at the same elevation as the annular vent passage at position 304 A.
Referring now to FIG. 4A the installation of the vent exhaust fan 413 (with conventional on/off and/or proximity switch), the vent exhaust fan upstream isolation valve 414 , the bypass branch line 411 , and the branch line isolation/throttle valve 412 are illustrated according to one embodiment of the present invention. The bypass branch line and the branch line isolation/throttle valve exist to ensure continued vent exhaust fan flow even with toilet overflow or condensate buildup. This will prevent damage to the vent exhaust fan under upset conditions when there is no flow through the annular vent passage. FIG. 4B illustrates the installation of the vent exhaust fan at a significantly higher elevation (not to scale) than the other components, without a vent exhaust fan upstream isolation valve or a branch line isolation/throttle valve but with the bypass branch line according to another embodiment of the present invention. The utility box 403 is illustrated in FIGS. 4A and 4B . In FIG. 4A the utility box includes the vent exhaust fan 413 , bypass branch line 411 with branch line isolation/throttle valve 412 , and the vent exhaust fan upstream isolation valve 414 . In FIG. 4B the louvered utility box is in the same relative location but with the vent exhaust fan at a higher elevation, no vent exhaust fan upstream isolation valve and the bypass branch line without a branch line isolation/throttle valve.
Any combination of the embodiments depicted in FIGS. 4A and 4B may be employed, depending on the intended approach to maintenance activities.
Referring now to FIG. 5 the flow path of the ventilation exhaust from the toilet rim as it enters through the vent exhaust orifices 511 , travels through the ventilation exhaust annulus 504 , out the rear vertical plane 516 of the toilet bowl, as the annular exhaust vent line 515 to the low point drain line 507 , through the upwardly sloped portion of the annular exhaust vent line, to the enlarged connection 509 at the rear vertical plane 517 of the toilet, and up through the parent exhaust line 508 , vent exhaust fan upstream isolation valve 514 , through the vent exhaust fan 513 and to the outside according to one embodiment of the present invention. Some ventilation flow also will exist through the bypass branch line 505 during vent exhaust fan operation to protect the fan against no-flow conditions.
One embodiment of the present invention consists of a standard toilet configuration but with an annular vent passage 111 and vent exhaust orifices 511 integral to the toilet bowl rim. The annular exhaust vent line 515 exits the toilet bowl so as not to interfere with the current art liquid flushing configuration. The vent exhaust orifices 511 would be located above and radially inside the current rim jet orifices 512 . This would prevent any water intrusion into the vent exhaust orifices during the normal flushing operation of the toilet. The annular exhaust line may exit the bowl through an opening at the rear vertical plane 516 of the toilet bowl. The continuing annular exhaust vent line will unavoidably slope downward from the toilet bowl rim and, therefore, create a low point where collection of liquid would occur due to toilet overflow or condensation. This location would serve as the low point drain for the vent exhaust system. At this low point location there would be installed a tee-off low point drain line 507 from the annular exhaust vent line. To ensure positive drainage of the annular exhaust vent line and the parent exhaust line 508 under all conditions, this drain line length is greater than the height of the water column equivalent to the maximum suction pressure possible from the vent exhaust fan. The low point drain line 507 would have a petcock or other type of valve 310 installed at the bottom of the low point drain line. If exhaust ventilation flow is ever interrupted by toilet overflow or by collection of condensation, this low point drain valve may be opened to drain all liquid from the exhaust line even with continued vent exhaust fan operation. Alternatively, the low point drain valve could be left open for normal operation and closed only for vent line back flushing during maintenance as discussed further below. The low point drain valve would be closed for maintenance back flushing and open to drain the vent exhaust path upon completion of flushing operations.
From the low point drain line 507 in the annular exhaust vent line 515 , the annular exhaust vent line must continue on an upward slope to the connecting vertical portion of the parent exhaust line 508 in which will be located the vent exhaust fan upstream isolation valve 514 and the vent exhaust fan 513 . To avoid fragility and to add to the aesthetics of the toilet, it is preferred to mold the annular exhaust vent line integral with the existing body mold of the toilet for that portion of the annular exhaust vent line which is upstream the rear vertical plane 517 of the toilet. However, the annular exhaust vent line upstream the rear vertical plane 517 of the toilet may be created with materials and components that are not integral to the toilet mold. An upward slope of at least 3 millimeters per 0.3 meters of piping from the low point drain line must be maintained as the annular exhaust vent line and the parent exhaust line continue to the vent exhaust fan 513 . To ensure adequate vent exhaust flow, the size of the annular exhaust vent line 515 and the parent exhaust line 508 would need to be matched appropriately with the performance capability of the vent exhaust fan 513 . The annular exhaust vent line 515 would exit the rear vertical plane of the toilet 517 , connect with the enlarged connection 509 of the parent exhaust line 508 , and enter the wall. The enlarged connection may be made with an 0 -ring seal, threaded, glued fitting, hose clamp, or any other connecting type device and using either flexible or rigid piping from any of a number of material types. Enlarging the parent exhaust line would be advised to reduce the head loss in the exhaust line and increase the vent exhaust flow rate. The parent vent line would continue to the vent exhaust fan 513 and discharge to the outside or to a means to deodorize and return the air. The vent exhaust fan inlet must be located above a minimum height equal to the sum of the level of the toilet rim plus the equivalent water column expected from the maximum suction pressure of the vent exhaust fan. That is, the vent exhaust fan is not located below the toilet bowl rim.
Operation of the vent exhaust fan would be controlled with a standard on/off wall switch or a proximity switch and power source as employed in current art. An optional embodiment is to appoint the vent exhaust fan with a rheostat controller to allow adjustment of the vent exhaust fan flow rate. The rheostat control of the vent exhaust fan also is current art.
A bypass branch line 505 would be installed at a minimum elevation greater than the sum elevation of the toilet rim plus the maximum suction pressure of the vent exhaust fan 513 and installed upstream of the vent exhaust fan upstream isolation valve 514 . The bypass branch line 505 is installed to provide a bypass flow capability such that a no-flow condition for the vent exhaust fan 513 would never occur, even with toilet overflow or condensate buildup blocking flow from the upstream portion of the vent exhaust path. This bypass branch line also would serve as the maintenance connection for back flushing of the exhaust system. To ensure the bypass flow is properly matched with the fan capabilities while maintaining adequate exhaust ventilation flow, the bypass branch line 505 may or may not include a branch line isolation/throttle valve 510 .
To accommodate back flush maintenance of the vent exhaust orifices 512 , the annular vent passage 504 , the annular exhaust vent line 515 , the parent exhaust line 508 , and a vent exhaust fan upstream isolation valve 514 (one such as a gate valve or ball valve to reduce head losses) may be installed upstream of the vent exhaust fan 513 . The vent exhaust fan upstream isolation valve 514 would be open during normal operation and shut only during maintenance back flushing. The vent exhaust fan upstream isolation valve 514 would serve to prevent water intrusion into the vent exhaust fan inlet during maintenance back flushing operations.
Another embodiment would be to raise the vent exhaust fan to a higher elevation to preclude the need for a vent exhaust fan upstream isolation valve. This embodiment would be appropriate so long as the pressure source of fluid for back flush operations would not exceed the equivalent water column height to the vent exhaust fan inlet. This arrangement also would avoid water intrusion into the vent exhaust fan inlet during maintenance back flushing operations.
To avoid a potentially damaging no-flow condition for the vent exhaust fan, the vent exhaust fan would be turned OFF during back flushing activities when a single vent exhaust fan exhausts a single toilet. Turning off the vent exhaust fan may not be necessary if the vent exhaust fan exhausts multiple toilets as sufficient flow may be available from the other vent exhaust paths even as flow is completely isolated from one toilet during the back flushing operation or resulting from toilet overflow or condensate buildup in the vent exhaust system of an individual toilet.
Any combination of the arrangements described in paragraphs [0042], [0043], and [0044] may be employed, depending on the intended approach to back flush maintenance capabilities.
For convenience and accessibility, the vent exhaust fan, the vent exhaust fan upstream isolation valve (if installed), the bypass branch line, and branch line isolation/throttle valve (if installed) may be installed in a louvered connection box integral to the back wall. This connection box must be louvered to permit flow through the bypass branch line.
The phenomenon of capillary action must be considered. Capillary action would occur if water were to be introduced into the vent exhaust orifices. Capillary action results in a residual water column in each orifice even after normal drainage, the water column level dictated by the individual radius of the vent exhaust orifices. The suction pressure of the vent exhaust fan must be adequate to overcome the resulting water column so vent exhaust flow can be reestablished and maintained after the vent exhaust orifices are flooded. Therefore, proper vent exhaust orifice sizing for adequate vent exhaust flow as well as for consideration of capillary action must be determined to be compatible with the vent exhaust fan performance specifications (i.e., its fan performance curve).
Use of a positive displacement exhaust driver instead of a common exhaust fan would negate the innate features of this invention which avoid equipment damage and ensure effective vent line drainage after a toilet overflow, condensate buildup, or post maintenance back flush condition. Also, a vent exhaust fan, contrary to a positive displacement or high pressure ventilation mechanism, would have a relatively low suction pressure so that the suction force would do little to cause any debris to clog the vent exhaust orifices, annular vent passage, annular exhaust vent line, or parent exhaust line. These design attributes of this invention make it easy for the maintenance back flush operation to clear any obstructions and restore toilet exhaust ventilation.
The internal vent exhaust path according to an embodiment of the proposed invention will more effectively and more efficiently contain and remove toilet gases with less required energy and in less time than the current art. The use of a dedicated vent exhaust fan would reduce energy consumption without sacrifice to efficiency or effectiveness. A dedicated vent exhaust fan or a vent exhaust fan of shared use may be placed on a rheostat so that vent exhaust fan flow rate could be adjusted according to need. However, at all times the suction pressure of the vent exhaust fan must be adequate to meet the vent exhaust flow requirements and overcome any concerns associated with capillary action.
In a preferred embodiment of the present invention, a toilet comprises a toilet bowl with an upper rim which includes a separate, integrally-molded inner circumferential, annular vent passage with multiple vent exhaust orifices in number and size to be compatible with vent exhaust flow needs and the vent exhaust fan performance specifications. The annular vent passage connects to the annular exhaust vent line at the rear vertical plane of the toilet bowl and would be molded into the body of the toilet and would slope downward to the low point drain line as it exits the toilet bowl and then slope continuously upward from the low point drain line toward the back of the toilet. At the bottom of the low point drain line, a low point drain isolation valve is located. The low point drain line would be of adequate length to drain the parent exhaust line even during exhaust fan operation. Therefore, the length of the drain line must be greater than the maximum suction pressure capability of the vent exhaust fan. The properly sized annular exhaust vent line follows the contour of the toilet mold as it slopes upward to the rear of the toilet. At this point the annular exhaust vent line connects to the enlarged parent exhaust line. This connection would be made using any of the various means discussed previously. The parent exhaust line will continue to the vent exhaust fan which will be preceded by the vent exhaust fan inlet isolation valve (gate valve or equivalent for minimizing head loss). The vent exhaust fan upstream isolation valve for the vent exhaust fan could be excluded if the vent exhaust fan is installed at an elevation that would exceed the equivalent elevation of the head pressure from any back flushing source of fluid. Upstream of the vent exhaust fan upstream isolation valve would be connected a bypass branch line properly sized with or without an in-line branch line isolation/throttle valve to ensure reliable vent exhaust fan operation under all conditions without damaging the vent exhaust fan. The bypass branch line would be installed at a minimum elevation greater than the sum elevation of the toilet rim plus the maximum suction pressure of the vent exhaust fan and installed upstream of the vent exhaust fan upstream isolation valve (if installed). The vent exhaust fan outlet will be connected to the continuing parent exhaust line and vent to the outside.
Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art, and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference. | This invention pertains to an internally exhausted toilet bowl which employs basic principles of fluid flow to provide reliable, more efficient, and more effective removal of noxious toilet odors while reducing energy consumption when compared to current art. This is accomplished during all conditions of normal operation. In case of toilet overflow or condensate buildup, the impact on the vent exhaust path from these upset conditions can be resolved easily, and normal operation can be restored without damage to any components. Additionally, this invention includes maintenance features that would provide means for back flushing the annulus vent line and orifices if clogging ever were to occur. | 4 |
DESCRIPTION
The invention relates to reel stands, the function of which is to pick up reels of paper, generally from transporting means, and to lift them and place them in an unreeling or working station and also the reverse function, namely, to put the reels down on said transporting means once the reels have been used up or as otherwise required.
Such reel stands incorporate pairs of arms which are designed to pick up the reels between them, for which purpose the arms have at their ends support cones which locate in the ends of a hollow support shaft on which the reels are mounted.
In known reel stands each pair of arms can only carry out two movements, the first of which is in a horizontal plane for mutual approach or separation, in order to move them into or move out of engagement with the support shaft of the reel and the other of which is a turning movement in order to lift the reel, once grasped, into the working position or to lower and deposit the reel when it had been exhausted or when it has to be replaced.
Since the reels to be used may have different diameters, their shafts will be at different heights relative to the ground. As a result of this and since the arms of the known reel stands only describe two movements, the horizontal one of mutual approach or separation which has to take place when the support cones are already facing one another or aligned with the hollow shaft, and the turning movement which has to be the one that brings the support cones into alignment with said hollow shaft, said alignment is not achieved in the majority of occasions since a circumferential arc which always has the same radius cannot always coincide with different shaft heights.
To overcome this problem the support cones are positioned as close as possible to the hollow shaft of the reel and then the latter has to be moved into alignment which, because of its dimensions and weight, is a complex, slow and very difficult job. This problem is aggravated by the fact that, in addition to the difficulties involved in the operation, it is impossible to automate the process of loading and unloading the reels completely so that this stage of the process is an impediment to complete automation.
The object of the present invention is to solve or mitigage this problem by arranging for the arms additionally to be movable in a vertical plane.
The combination of the vertical and turning movements of the arms of the reel stand enables their support cones to take up any required position within an area which is always sufficient to bring about their alignment with the longitudinal axis of the hollow shaft of the reels.
According to one preferred embodiment, since the hollow shaft of the reels will be positioned at a height which may differ as a function of the diameter of the same, but always lies in the same vertical plane, in order to pick up a reel, the arms of the reel stand will describe a downward turning movement until they reach the lowest possible position within said vertical plane in order to pick up or put down the reel with the smallest diameter. Once they are in this position and by virtue of the third movement in a vertical plane, said arms will rise until the support cones meet with the hollow shaft of the reel, and will then engage it and establish the necessary coupling.
Preferably the different rectilinear movements of the two pairs of arms of a reel stand in the horizontal and vertical planes are achieved with a single motor drive.
The invention is diagrammatically illustrated, by way of example, in the accompanying drawings, in which:
FIG. 1 is a perspective view of a reel stand;
FIG. 2 is a side view elevation of a reel stand, showing the turning movement of the arms;
FIG. 3 is a side elevation of the reel stand as in FIG. 2 and showing the vertical movement of the arms;
FIG. 4 is a section of a motor which drives the mechanism of the reel stand and its central power distribution shaft;
FIG. 5 shows in profile a partial section of the reel stand showing a drive shaft (7) and the coupling to a lifting screw (13);
FIG. 6 shows in profile a partial section of a coupling between a drive shaft (6) and an opening and closing drive;
FIG. 7 shows a lifting screw (13) in profile;
FIG. 8 shows the opening and closing drive in profile;
FIG. 9 is a sectional elevation of an arm turning drive, and
FIG. 10 is a diagram of the chain of movement of the mechanisms driving the arms (1).
EXPLANATORY DETAILS
1. Arms
2. Main support shaft
3. Columns
4. Motor
5. Distribution box
6. Drive shaft
7. Drive shaft
8. Reversing box
9. Support housing
10. Reel support cones
11. Central distribution shaft
12. Clutches
13. Lifting screw
14. Intermediate shaft
15. Drive
16. Transverse screw
17. Brake
18. Crown wheel
19. Rack
20. Cylinder
21. Mechanism for slow precise movements
22. Initial portion of the arms (1)
A stand for reels of paper is shown in the drawings. As can be seen in diagrammatic form in FIG. 1 in a view which shows a pair of arms (1) on only one side of the reel stand, these arms (1) which pick up the reel from its corresponding means of transport are fitted by means of their initial portion (22) on a main support shaft (2) each end of which is connected to a support housing (9) each of which can move in a vertical direction in a pair of columns (3). In accordance with the present invention, the arms (1) and their support cones (10) which extend into the hollow shaft or spindle of the reels can be provided with the following movements:
1. Vertical displacement of the arms (1) in an upward or downward direction, see FIG. 3.
2. Oscillation of the arms (1) turning with the main support shaft (2) and following the path of an arc, see FIG. 2.
3. Approach and separation of the arms (1) including joint and synchronised movement of the arms (1) to one or other side, see FIG. 1.
Thus, for example, as shown in FIGS. 2 and 3, in order to allow the entry of a new reel, the arms (1) may move to an upper position after which the arms (1) and the main shaft (2) turn in a downward direction so that the support cones (10) take up the lowest position on the vertical line through the centre of the means transporting the reels. This makes it possible to pick up reels of smaller diameters. From the lowest position, the pair of arms (1) moves upward vertically until sensors detect the central hollow shaft of the reel and, at this moment, the arms (1) approach, moving the cones (10) inwards and taking hold of the reel which is then raised to the working position by means of the upward turning movement of the arms (1).
Preferably the rectilinear movements in both horizontal and vertical directions of all of these movements are powered by a single motor (4) and a series of mechanical devices producing synchronisation. Obviously, the motor (4) could be replaced by a number of motors. Through a distribution box the motor (4) drives two pairs of drive shafts (6 and 7) which respectively move each pair of arms (1) on the two sides of the machine.
In each pair of drive shafts (6 and 7), the shaft (6) drives the mechanism for approach or separation of the arms (1) while the shaft (7) controls the raising or lowering.
The drive shaft (6) is connected to a reversing box (8) which, by means of a set of gears, enables both arms (1) to be moved simultaneously and to one side or another so that the area of wear of the components of the machine is spread.
As can be seen in FIG. 4, the motor (4) acts through a mechanism (21) provided optionally to achieve slow precise movements, driving a central distribution shaft (11) in the box (5). On either side of the motor (4) there are symmetrical bevel gears which act on the two pairs of shaft (6) and (7), with clutches (12) between the corresponding gear and said shafts which are only actuated by the corresponding automatic system when it is necessary to describe a movement.
In each column (3)--see FIG. 6--the transverse shaft (6) acts through a bevel gear drive on an intermediate shaft (14) which is disposed vertically and has longitudinal grooving or a similar solution which allows movement of a bevel gear, see FIG. 8. This bevel gear in turn acts via a horizontal shaft with a drive (15) on a transverse screw with ball bearings (16), producing the corresponding horizontal approach or separation movement of the arms (1).
On the other hand, each transverse shaft (7)--see FIG. 5--acts through a pair of bevel gear assemblies to drive a pair of lifting screws (13) which, being located in the end support housings (9), raise or lower the arm assembly (1). As can be seen in FIG. 7, in its upper part each screw (13) has a brake (17) which prevents any undesired movement of the assembly as a result of the weight of the reels when the arms (1) are in the raised position.
In each support housing (9) there is a crown wheel (18) which is integral with the main support shaft (2) of the arms (1); said crown wheel (18) engages with a rack (19) which is the rod of a double-acting hydraulic cylinder (20). According to this, in order to turn the arms, it is merely necessary to drive fluid under pressure to one or other end of the cylinder (20) which will cause the entire arm (1) and shaft (2) assembly to turn.
The assembly comprising the described mechanisms can be seen in a simplified chain of movement in FIG. 10 which only shows the mechanical drive for one pair of arms since the corresponding drive to the other pair is symmetrical. This chain of movement in FIG. 10 shows how, by means of ther reversing box (8), it is possible for one of the two screws (16) designed for the horizontal movements and capable of rotating in either direction to change its direction of rotation so that the arms (1) can move jointly towards either end of the machine in order to distribute working times and wear in addition to approaching or separating from one another.
FIGS. 2 and 3 show how, in one example of an installation the reels are brought up to the reel holder by transporting trucks which run on rails on which it is possible to dispose optional accelerating mechanisms with a retractable arrangement like those shown operating on the reels of a smaller diameter by tangential contact with the same. | A reel stand of the kind having a pair of arms (1) capable of horizontal movement towards and away from one another and pivotal movement in a vertical plane, characterized in that the arms (1) are vertically movable in translation, the conjunction of which vertical translational movement with the pivotal movement enables cones (10) on the arms (1) to reach positions of alignment with the support shafts of paper reels of different diameters. | 1 |
TECHNICAL FIELD
The present invention relates to the recovery of transmitted data signals in a digital communications system and, more particularly, to a technique for improving the operation of timing and carrier recovery circuitry in communications systems in which independent data signals are simultaneously transmitted on carrier signals having orthogonal polarizations.
BACKGROUND OF THE INVENTION
The burgeoning growth of terrestrial and satellite communications systems has been accompanied by the need to provide higher and higher information-carrying capacities within a limited frequency band. One of the techniques used to fulfill this need has been to simultaneously transmit independent data signals on carrier signals which have orthogonal polarizations and which occupy the allotted frequency band. This use of modulated, orthogonally-polarized carrier signals can double the information-carrying capacity of a communications link. However, time-varying distortion, such as rainfall, imperfect antenna alignment, etc., collectively known as fading, can interfere with the operation of carrier and timing recovery circuitry in the system receiver. Such circuitry is respectively used for demodulating the incoming carrier signal and then sampling the demodulated signal to reconstruct the data. At times, the fading is so severe that the carrier and timing recovery circuits are no longer synchronized to the incoming and the data signals can't be recovered.
One general class of techniques to reduce fading-induced data loss in systems which employ one or more carrier signal having a single polarization is to transmit the same data either over different line-of-sight routes or on a plurality of carrier signals having different frequencies. While these techniques, respectively known as spatial and frequency diversity, provide satisfactory results, their usage is not practical in certain applications and their cost can be prohibitive.
Other prior art attempts to minimize loss of the data signal caused by improper operation of carrier and timing recovery circuits have focussed on diminishing the acquisition time, i.e., the time required for such circuits to establish synchronization after synchronization has been lost due to severe distortion. While these attempts have been successful, there is still a loss of data during the acquisition time which exceeds the performance objectives of certain system applications.
SUMMARY OF THE INVENTION
The present invention overcomes the limitations of the prior art by utilizing common clock and carrier sources for each of the transmitted orthogonally polarized carrier signals. This creates a redundancy channel in so far as the timing and carrier information. In the system receiver, the data extracted from each of the orthogonal carrier signals is examined and, based on this examination, one of the received carrier signals, or data recovered therefrom, is used to control the regeneration of subsequent data from both of the orthogonal carrier signals. Advantageously, this data decision-directed approach, which can be applied with baseband and passband carrier and timing recovery circuits, lessens the likelihood that such circuits will lose synchronous operation as it is less likely that fading will simultaneously affect both orthogonally polarized carrier signals.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a block-schematic diagram of a transmitter which embodies the present invention;
FIG. 2 is a block-schematic diagram of a receiver which embodies the present invention for use with baseband timing and carrier recovery circuits;
FIG. 3 is a detailed schematic diagram of error signal generator 221, logic circuit 223 and carrier recovery circuits 220 of FIG. 2;
FIG. 4 is a signal constellation diagram which explains the operation of timing recovery circuit 222;
FIG. 5 is a block-schematic diagram of timing recovery circuit 222 of FIG. 2;
FIG. 6 is a block-schematic diagram of phase shifter 517, 518, 519 or 520 within timing recovery circuit 222;
FIG. 7 is a detailed schematic of another embodiment of logic circuit 223;
FIG. 8 is a block-schematic diagram of a receiver which incorporates the present invention for use with passband carrier and timing recovery circuits; and
FIG. 9 is a detailed schematic of logic circuit 801 and carrier and timing recovery circuits 802 and 803, respectively, of FIG. 8.
DETAILED DESCRIPTION
FIG. 1 shows the transmitting end of an illustrative communications system which transmits carrier signals on dual polarizations. As shown in FIG. 1, data signals on leads 101, 102, 103 and 104 are respectively coupled through bit stuffer 105 whicn ensures that each of the data signals is synchronized with respect to a common clock. This common clock is generated by oscillator 115 and is coupled to stuffer 105 via lead 114. Digital-to-analog converters 110, 111, 112 and 113, each strobed by the clock signal on lead 114, quantize their supplied data signal into a finite number of predetermined signal voltages. These signal voltages are the permissible transmitted digital signal values. The resulting waveforms created by converters 110-113 are then spectrally shaped by half-Nyquist filters 116-119. Of course, filters which provide more arbitrary spectral shaping could be utilized.
We shall refer to the spectrally shaped waveforms respectively provided by filters 116 and 117 as the in-phase (I) rail and quadrature (Q) rails. These rails will be transmitted on carriers having a first polarization which we shall arbitrarily designate as the horizontal (H). Similarly, we shall also designate the shaped waveform provided by filter 118 as I and that provided by filter 119 as Q. These rails, however, will be transmitted on carrier signals having a second polarization which is orthogonal to the first. This second polarization will be designated as the vertical (V). To differentiate between the two I and two Q rails, subscripts shall be used to indicate the polarization. Multipliers 120 and 121 respectively modulate the amplitudes of a pair of quadrature-related carrier signals on leads 130 and 131 with I H and Q H . In similar fashion, multipliers 122 and 123 modulate the amplitudes of the quadrature-related carrier signals on leads 130 and 131 with I V and Q V . The modulated carrier signals are then coupled to one or more transmitting antennas (not shown) from which the carrier signals on leads 124 and 125 propagate in free space on the H polarization while the carrier signals on leads 126 and 127 propagate in free space on the V po-arization. In certain applications, "upconverters" (not shown) are disposed between the modulated carrier signals and the transmitting antennas to frequency translate the "intermediate" frequency (IF) of oscillator 115 to some preselected radio frequency. It should be noted that the use of the same oscillator and phase shifter for all four carrier signals creates redundancy in H and V polarized transmitted signals in so far as carrier recovery is concerned. In addition, there is redundancy with respect to timing information in both the H and V polarizations due to the use of bit stuffer 105 and the common clock signal on lead 114. As will be discussed, this redundancy is utilized by the present invention to minimize the loss of synchronization in the timing and carrier recovery receiver circuitry.
Refer now to FIG. 2. After propagating through the transmission channel, the H and V polarized modulated carrier signals are coupled from their respective receiving antennas (not shown) to leads 201 and 202. Demodulators 203 and 204 extract information-bearing analog signals from the received carrier signals using locally-generated carrier signals on leads 227 and 228 which are supplied by carrier recovery circuit 220. Half-Nyquist filters 230 and 231 then spectrally shape the analog signals produced by demodulator 203 before they are coupled to A/D converters 234 and 235. Half-Nyquist filters 232 and 233 provide similar spectral shaping to the signals from demodulator 204 and then couple these signals to A/D converters 236 and 237. A/D converters 234-237, are each strobed by an associated clock signal supplied by timing recovery circuit 222 on leads 240-243. Due to presence of distortion in the transmission channel, these converters typically produce distorted samples of I H , Q H , I V and Q V on each clock pulse. Cross-polarization canceller 209 and copolarization cancellers 210, utilizing error signals produced by error signal generator 221, remove the distortion in these samples so as to yield substantially distortion-free I H , Q H , I V and Q V samples and buses 211-214, respectively during proper receiver operation.
As will be shown, the present invention makes use of the redundancy in carrier and timing information in the orthogonally polarized carrier signals to reduce the likelihood that carrier recovery circuit 220 and timing recovery circuit 222 will have to reacquire synchronous operation. This benefit accrues from the fact that it is not likely that the fading wil- simultaneously affect both polarizations of the transmitted modulated carrier signals. In accordance with the present invention, circuitry is provided in the receiver which examines the data signals recovered from both polarizations and derives error signals associated with each polarization. The data signals from the polarization whose error signal meets a preselected criterion is then used by timing and carrier recovery circuitry to generate timing and local carrier signals which, in turn, are used to recover subsequent data signals from both polarized carrier signals. In one arrangement, the data signals are selected from one polarization so long as the associated error signal does not exceed a predetermined threshold. In another arrangement, the data signals are selected from the polarization having the smallest associated error signal. In either event, selection of the data signals used by the timing and carrier recovery circuits ensures synchronous operation of these circuits unless transmission channel distortion substantially affects both polarizations simultaneously.
The data signals on leads 211-214 are coupled to error signal generator 221, carrier recovery circuit 220 and timing recovery circuit 222. Error signal generator 221 forms an error signal each clock signal period for each data signal. This error signal is equal to the difference between the associated data signal and the closest one of the plurality of permissible transmitted digital signal values. These error signals appear on bus 229 wherein they are coupled to X-pol canceler 209, co-pol canceler 210. Cancelers 209 and 210 use the error signals, in well-known fashion, to update the tap-weight coefficients therein so that the compensation provided tracks the X-pol and co-pol distortion in the transmission channel. Error signal generator 221 also combines the error signals associated with data signals extracted from the same carrier signal to produce a pair of error signals, one associated with each of carrier signals. This pair of error signals is coupled via leads 260 and 261 to logic circuit 223 wherein they are examined to determine whether the data signal from the H-pol or V-pol carrier signals will be used by carrier recovery circuit 220 to generate the local quadrature-related carrier signals on leads 227 and 228, and by timing recovery circuit 222 to generate the clock signals on leads 240-243.
As shown in FIG. 3, error signal generator 221 includes ROMS 320-323 and summers 324-327. Each ROM receives a different one of the data signals on leads 211-214 and maps this data signal into the closest one of the permissible transmitted digital signal values. The output of each ROM is then coupled to a different summer which forms an error signal. Each error signal is equal to the difrerence between the data signal coupled to a ROM and its mapped ROM output. In this manner, summers 324-327 respectively generate error signal e I .sbsb.H, e Q .sbsb.H, e I .sbsb.V, e Q .sbsb.V, wherein the subscript indicates the data signal from which the error signal was derived. These error signals are coupled to X-poi canceler 209 and co-pol canceler 210 via bus 229.
The four error signals generated by summers 324-327 are also coupled to ROMS 328-331. ROMS 328 and 329 respectively receive e I .sbsb.H and e Q .sbsb.H and output the algebraic square of each error signal. Summer 332 then adds these ROM outputs to form an error signal on lead 260 associated with the H-pol carrier signal and designated as e H 2 . Similarly, ROMS 330 and 331 respectively form the algebraic square of e I .sbsb.V and e Q .sbsb.V pk which are then added by summer 333 to form an error signal on lead 261 associated with the V-pol carrier signal and designated as e V 2 .
Error signals and e H 2 and e V 2 are supplied to logic circuit 223 where comparators 340 and 341 respectively compare tnese error signals to corresponding reference signals REFl and REF2. While these reference signals are typical-y the same, they need not be so. Eacn of these reference levels represents the maximum acceptable error signal magnitude. Comparators 340 and 341 respectively generate logic signals K 1 and K 2 on leads 250 and 251 which are coupled to timing recovery circuit 222. Each of these logic signals are equal to logic "1" when their associated error signal is greater than its reference level and is logic "0" at other times. Logic signals K 1 and K 2 are also coupled through AND gates 342, 346, OR gate 343 and inverters 344 and 345 which form logic signals D 1 and D 2 on leads 224 and 234. Signals D 1 and D 2 can be expressed as:
D.sub.1 =K.sub.1 K.sub.2 +K.sub.2 ; and
D.sub.2 =K.sub.1 K.sub.2 ;
where multiplication and addition respectively indicate the Boolean algebraic AND and OR operations, and a line over a symbol indicates the inversion of that symbol.
As will be shown, signals D 1 , D 2 , K 1 , and K 2 are used to select the data signals on leads 211-214 processed by carrier recovery circuit 220 and timing recovery circuit 222.
Within carrier recovery circuit 220, data signals I H and Q H address ROM 350 whiIe data signals I V and Q V address ROM 351. To save memory size, these ROMS can be addressed by a portion of the bits of each data signal which is sufficient to determine the data signal value. ROM 350 produces a pulse on leads 352 or 353 depending on the bits comprising IH and QH and ROM 351 produces a pulse on leads 354 or 355 based on the bits comprising I V and Q V . These pulses are coupled to tristate gates 303-306 which couple their input signals to counter 307 when the associated control signal on leads 224 or 234 is logic "0" and provide an open circuit when this control signal is logic "1". Accordingly, either the signal pulses from ROM 350 or ROM 351 are connected to counter 307. Pulses on leads 352 or 354 increment the count of counter 307 by one while pulses on leads 353 or 355 decrement the count of counter 307 by one. Bus 310 couples the current count through D/A converter 311 to oscillator 312 where the analog representation of the count, provided by converter 311, drives local quadrature-related carrier signals on leads 227 and 228 into phase alignment with the incoming modulated carrier signals. One of these local quadrature-related carrier signals appears at the output of oscillator 312 and the other is formed by coupling the output of oscillator 312 through -π/2-phase shifter 319.
To understand how carrier recovery circuit 220 provides local quadrature-related carrier signals which are phase-aligned to the incoming carriers, refer now to FIG. 4.
FIG. 4 shows an illustrative 16 QAM signal constellation in which the permissible transmitted signal values in both the I and Q rail are ±1 and ±3. The 16 resulting data points are designated as 401-416. By choosing thresholds 430 passing through each data point and thresholds 431 crossing midway between each data point and its immediate neighbors, the 4 qaudrants of FIG. 4 can be divided into 64 quadrants as shown. Consider now the effects of phase error. The lack of phase alignment between the local quadrature-related carriers and the incoming carriers causes a rotation of the signal constellation. When the misalignment is in a first direction, the data points fall in quadrants 417 but when the phase misalignment is in the opposite direction the data points fall in quadrants 418. The appearance of the data points in quadrants 419 and 420 provide no useful information about phase alignment and these occurrences are ignored.
In view of FIG. 4, ROMS 350 and 351 in FIG. 3 map their supplied data signals into a pulse appearing on leads 352 or 354 which increments the count of counter 307 by one when the received data signals fall in quadrants 417 and a signal pulse on leads 353 and 355 which decrements the count of counter 307 by 1 when the received data signals fall in quadrants 418. Oscillator 312 and phase shifter 319, in turn, varies the phase of the local quadrature-related carrier signals on leads 227 and 228 relative to the incoming carriers in response to the analog representation of the count of counter 307.
FIG. 5 shows the circuitry within timing recovery circuit 222 for generating the clock signal on leads 240-243 in FIG. 2. One data signal from the H-pol carrier signal on buses 211 or 212 and one data signal from the V-pol carrier signal on buses 213 or 214 are coupled through tristate gates 501 and 502 to a shift register comprising delay elements 504-506. Gates 501 and 502 are respectively controlled by the logic signals on leads 234 and 224 in the same manner as the tristate gates in carrier recovery circuit 220 so that an H or V -pol data signal, depending on the magnitude of e H 2 and e V 2 , is coupled to delay elements 504-506. Each of these delay elements is a parallel-in, parallel-out device which, clocked by the signal on lead 516, provides a delay of one symbol period. Gates 501 and 502 also selectively couple the data signal to ROM 507 which quantizes each received signal into the closest one of the permissible data signal values. Summer 508 subtracts this quantized value from the associated received data signal to form an error signal. This error signal is coupled to truncator 531 which is a digital magnitude comparator that outputs a logic "0" when the polarity of the error signal is positive and a logic "1" when this polarity is negative. The output of truncator 531 passes through delay element 509 and appears on lead 521 as part of the address for PROM 510. The balance of this address is the outputs from the shift register delay elements appearing on buses 522, 523 and 524. Delay element 509 is needed to ensure that the error signal appears on lead 521 when the associated data signal, i.e., the data signal from which the error signal was derived, appears on bus 523.
PROM 510, addressed by the bits of three consecutive data signals and a representation of the error signal polarity, outputs a logic signal on leads 511 or 512 in response to certain addresses which respectively increments or decrements the count stored in counter 513 by one. These certain addresses correspond to times when the bits of the three consecutive data signals from delay elements 504-506 indicate the data signals are successively increasing or decreasing. If this is not the case, PROM 510 does not change the count stored in counter 513. Specifically, PROM 510 is programmed to increment the count by one when the bits of the three consecutive data signals indicate the data signals are successively increasing and the error signal polarity is positive, i.e., a logic "0" signal on lead 521, or when the error signal polarity is negative, i.e., a logic "1" on lead 521 and the bits indicate the three data s:gnals are successively decreasing. Similarly, PROM 510 decrements the count in counter 513 by one when the bits from delay elements 504-506 indicate the data signals are successively increasing and the polarity of the error signal is negative or when the polarity of the error signal is positive and the bits from delay elements 504-506 indicate the three data signals are successively decreasing. This operation of PROM 510 will drive oscillator 515 into phase lock with oscillator 115 of FIG. 1.
The count stored in counter 513, after being converted into an analog waveform by A/D converter 514, is coupled to oscillator 515 wn:ch, in response thereto, increases or decreases its phase relative to oscillator 115. The output of oscillator 515 on lead 516 is a clock signal which is phase and frequency locked to the clock signal on lead 114 of FIG. 1 which is the clock rate of the incoming data signals. However, since the H and V-pol carrier signals can propagate to the receiver over different paths, a fixed phase offset can exist between the clock signal on lead 516 and the optimum sampling times for each of the data signals not processed by PROM 510. Therefore, the clock signal on lead 516 is coupled in parallel through four identical phase shifters 517 through 520 to respectively derive clock signals on leads 240-243 which occur at the optimum sampling times. Each of these phase shifters is supplied with a corresponding one of the data signals and a corresponding one of the logic signals from leads 250 or 251.
FIG. 6 shows the circuitry within each of the phase shifters 517 through 520. As discussed, the data signal on buses 211, 212, 213 and 214 are respectively coupled to phase shifters 517-520. Within each phase shifter, as illustrated in FIG. 6, the supplied data signal is coupled to parallel-in, parallel-out shift registers 607-609 whicn are strobed by the corresponding phase shifted clock signal on leads 240, 241, 242 or 243. This supplied data s:gnal is also coupled tnrougn circu:try including ROM 613, summer 614, truncator 615 and delay e-ement 616 so as to produce on lead 617 a digital representation of the polarity of the error s:gnal generated by summer 614. Th:s c:rcu:try operates in the same manner as ROM 507, summer 508, truncator 531 and delay element 509 in FIG. 5. PROM 606, supplied with the signal on lead 617 and the outputs of shift registers 607-609, functions in the same manner as PROM 510 of FIG. 5 to output a signal on lead 619 and 620 which respectively increments or decrements the count of counter 621. Counter 621 is designed to output an overflow signal on lead 622 and an underflow signal on lead 623 upon reaching predetermined limits. These limits can be selected to provide the desired amount of integration. The overflow and underflow signals are then coupled to up/down counter 124 which, in turn, supplies a multibit word on bus 650 which represents the count. This word is coupled through tristate gate 627 to digitally programmable phase shifter 628. The number of bits in the multibit word on bus 650 is selected to provide the requisite phase shift sensitivity wherein the greater the number of bits the smaller the minimum phase shift change provided.
Digitally programmable phase modifier 628 alters the timing of the input clock signal on lead 516 in accordance with the multibit word on bus 650 to produce the associated phase shifted clock signal on leads 240-243. Advantageously, the phase shifter of FIG. 6 is provided with circuitry, comprising tristate gates 626 and 627 and inverter 660, which ignores the multibit word on bus 650 when the data signal supplied to the circuitry of FIG. 6 on buses 21-, 212, 213 or 214 has distortion which exceeds the permissible amount. Such occurrences are indicated by a logic "1" state of signal K 1 for data signals I H and Q H and a logic "1" state of signal K 2 for I V and Q V . Accordingly, when the associated logic signal on lead 250 or 251 is logic "1", tristate gate 627 proves a high impedance output which effectively disconnects programmable phase adjuster from bus 650 and inverter 660 causes tristate gate 626 to couple a fixed address to phase adjuster 628. This fixed address is selected to set the phase change provided at some nominal level so that the optimum phase shift can be readily provided after normal operation of the phase shifter of FIG. 6 is restored.
In the embodiment of the present invention described hereinabove, logic circuit 223 generates logic signal D 1 and D 2 which control the data signals used by the carrier and timing recovery circuits. Specifically, the data signals extracted from a preselected one of the polarized carrier signals are selected so long as the error signal associated with this carrier signal meets a prescribed criterion. If not, the data signals extracted from the other polarized carrier signal are selected. Of course, other logic circuit arrangements are possible. For example, FIG. 7 shows another embodiment of logic circuit 223 comprising comparator 701. In this embodiment, a logic "1" signal is generated on lead 234 when e H 2 ≧e V 2 or a logic "1" signal is generated on lead 224 when e V 2 >>e H 2 . As a result, the data signals used by carrier recovery circuit 220 and timing recovery circuit 222 are those extracted from the carrier signal having the smaller associated error signal.
The present invention, while disclosed thus far in reference to baseband carrier and timing recovery circuits, is also applicable to passband versions of of these circuits. Refer now to FIG. 8 which shows a block diagram of an embodiment of the present invention utilizing passband carrier and timing recovery circuits. FIG. 8 is identical in operation to FIG. 3 except for the use of a different logic circuit 801 and, of course, different carrier and timing recovery circuits which are respectively designated as 802 and 803. FIG. 9 shows the detailed schematics of these circuits. As shown in FIG. 9, logic circuit 801 comprises comparators 340 and 341, inverter 930 and AND gate 931. Comparators 340 and 341 are identical to those in FIG. 3 and function in the same manner to generate logic signals K 1 and K 2 and e H 2 and e V 2 . Inverter 930 and AND gate 931 are arranged to generate control signals D 1 and D 2 from K 1 and K 2 , such that
D.sub.1 =K.sub.1 ; and
D.sub.2 =K.sub.1 K.sub.2 ;
wherein multiplication indicates a Boolean AND operation and a line over a symbol indicates the inverse of that symbol.
Carrier recovery circuit 802 includes two multipliers 910 and 911 which respectively multiply the H and V-pol carrier signals by 4 so as to generate a tone at 4 times the frequency of oscillator 128 of FIG. 1. This operation is required because the signals on leads 201 and 202 are each a suppressed carrier double-sideband signal. Switches 912 and 913, respectively under the control of logic signal D 1 and D 2 , selectively couple the outputs of multiplier 910 and 911 to summer 914. Accordingly, summer 914 receives the H and V-pol carrier signals, each multiplied by 4, when the error signal associated with the H-pol carrier signal is less than REF2 and the error signal associated with the V-pol carrier signal is less than REFl. Forming this sum advantageously increases the signal-to-noise ratio by 3 dB and thereby improves the jitter performance of carrier recovery circuit 802.
The output of summer 914 is supplied to phase detector 915 which is arranged in a loop with oscillator 917 and low pass filter 916 to generate a local carrier signal at 4 times that of oscillator 128. This carrier signal is then frequency translated by divide by 4 circuit 918 and coupled through a -π/2 phase shifter to generate a pair of quadrature-related carrier signals on leads 227 and 228 which are phase and frequency locked to the incoming carrier signals on leads 201 and 202.
Timing recovery circuit 803 comprises envelope detector 920 and 921 which respectively receive the H and V-pol carrier signals. The detected carrier signal envelopes, in turn, are coupled through switches 922 and 923 to summer 924. Switches 922 and 923 operate in response to logic signals D 1 and D 2 in the same fashion as switches 912 and 913. Summer 924 provides the same advantage as summer 914 in carrier recovery circuit 802. The recovered clock signal, which is frequency locked to the data signals within each of the incoming carriers, appears on lead 925. As the carrier signals can propagate over substantially different length paths to the receiver, this clock signal is coupled to phase shifters 517-520, which operate as described in FIG. 5, to generate 4 phase locked clock signals on leads 240-243 at the optimum sampling times.
It should, of course, be understood that while the present invention has been disclosed with reference to two specific embodiments, numerous other arrangements may be apparent to those skilled in the art without departing from the spirit and scope of the present invention. First, the present invention is applicable to a variety of different modulation formats, such as quadrature amplitude modulation (QAM), phase shift keying (PSK) or frequency shift keying (FSK), used in dual polarization communications systems. Moreover, while such systems utilize two quadrature-related carrier s:gnals in each poiarization, tne present invention can be applied so long as there is one carrier s:gnal in each po-arization. Second, while both carrier and t:ming recovery have been altered by the present invention, e:ther one alone can be altered where appropriate. This can arise, for example, in modulation formats such as frequency shift keying where carrier recovery is not necessary. | A technique is disclosed for improving the recovery of data signals transmitted on orthogonally polarized carrier signals by creating redundancy with respect to timing and carrier information. In the receiver, the carrier and timing recovery circuitry, which controls the recovery of the data signals from the incoming orthogonally polarized carrier signals, operate in response to a selected one of the carrier signals or at least one data signal recovered from this selected carrier signal. This selection is based on an examination of the data signals recovered from each of the orthogonally polarized carrier signals. Use of the described technique advantageously lessens the possibility of the carrier and timing recovery circuits losing synchronous operation during fading as it is less likely that a fade will simultaneously affect both orthogonally polarized carrier signals. As a result, data signal recovery is improved. | 7 |
RELATED APPLICATION
[0001] The present application is based on, and claims priority of, the U.S. Provisional Application No. 61/167,974, filed on Apr. 9, 2009, whose priority is herewith claimed, and whose disclosure is herewith included by a reference.
FIELD OF THE INVENTION
[0002] The invention relates to the measuring of fill levels, limits, pressure and flow. In particular, the invention relates to a sensor housing for a field device for fill level measuring, pressure measuring, limit measuring or flow measuring; to a field device; to a modular system for producing various field devices; and to the use of a sensor housing in a field device.
TECHNOLOGICAL BACKGROUND
[0003] Field devices are used for measuring a pressure, a fill level of a container, or a flow through a line. These field devices may be tailor-made according to specific customer requirements. This often entails relatively high expenditure. When the requirements which a field device is to meet change, this often necessitates the purchase of a new field device.
[0004] For energy supply, the field devices may be connected to an external energy source, for example using two-wire technology.
SUMMARY OF THE INVENTION
[0005] It is an object of the invention to facilitate the production and fabrication of field devices, and to improve the flexibility and application options of the field devices.
[0006] Stated are: a sensor housing for a field device for fill level measuring, pressure measuring, limit measuring and flow measuring; a field device comprising such a sensor housing; a modular system for producing various field devices for fill level measuring, pressure measuring, limit measuring or flow measuring; as well as the use of such a sensor housing in a field device according to the characteristics of the independent claims. Further embodiments of the invention are stated in the subordinate claims.
[0007] It should be noted that characteristics that below are, for example, described with regard to the sensor housing may also be implemented in the modular system or in the field device and vice versa.
[0008] According to an exemplary embodiment of the invention, a sensor housing for a field device for fill level measuring, pressure measuring, limit measuring and/or flow measuring is stated. The sensor housing comprises a housing body (also simply referred to as the “housing”) as well as a solar module. The solar module is designed in such a way that it can be placed on top of the housing body. Furthermore, the solar module is designed to supply the field device with electrical energy.
[0009] For example, the solar module is disconnectably connected to the housing body so that, when required, it can be affixed to, or removed from, the housing body.
[0010] For example, the sensor housing is designed so as to be multifunctional. This means that the sensor housing, if desired, can (as an alternative or in addition to the supply provided by the solar module) be connected to an external energy supply, for example to a two-conductor loop (4 . . . 20 mA).
[0011] According to a further exemplary embodiment of the invention, the sensor housing comprises an energy storage module for storing the electrical energy collected by the solar module. The housing body comprises a first chamber and a second chamber, wherein the energy storage device is arranged in the first chamber.
[0012] The solar module is, for example, placed on top of the first chamber so that an electrical connection to the energy storage device is established. In this arrangement the first chamber is closed off by the solar module, for example even in a manner so as to be waterproof.
[0013] According to a further exemplary embodiment of the invention, the sensor housing comprises a measured-value transmission module for transmitting measured values to an external unit, for example to a control unit, wherein the measured-value transmission module is arranged in the second chamber.
[0014] The second chamber may also be closed off with a corresponding housing cover.
[0015] The chambers are thus closable by means of a respective cover, and/or are divided from each other by means of a partition wall. The transmission module may be matched to the shape of the first chamber. For example, the transmission module is geometrically designed so that it fits into the second chamber. In the same manner the energy storage module, which is, for example, an accumulator or a capacitor circuit, can be matched to the shape of the first chamber so that no additional attachment of the energy storage module and the measured-value transmission module in the chambers is necessary.
[0016] According to a further exemplary embodiment of the invention, the solar module comprises a first group of electrical sliding contacts, wherein the housing body comprises a second group of electrical sliding contacts that corresponds to the first group. The electrical sliding contacts of the first group and of the second group are matched to each other in such a way that they make it possible to place the solar module on top of the housing body and an electrical connection between the solar module and the energy storage device, which connection is connected to the housing body, at various angles of rotation.
[0017] In other words, the solar module may be placed at different angles on top of the housing, and can be moved from this placement position to a locked position in which an electrical contact between the energy storage device and the solar module is established.
[0018] According to a further exemplary embodiment of the invention, the solar module is screwed onto the housing body. It is also possible to provide a bayonet closing device in order to attach the solar module to the housing body.
[0019] According to a further exemplary embodiment of the invention, the sensor housing comprises charge-protection electronics for the energy storage device, which charge-protection electronics are accommodated in the energy storage module.
[0020] According to a further exemplary embodiment of the invention, the sensor housing comprises a mounting connection that is used to affix the sensor housing to a mounting plate. The mounting plate can, for example, form part of a tank or can be connected to the tank.
[0021] According to a further exemplary embodiment of the invention, the mounting connection is designed to affix the sensor housing to a ball-and-socket joint head, as a result of which it becomes possible to tilt or rotate the sensor housing.
[0022] In this way it is possible to always set the solar module optimally in relation to the position the sun is in at the time, because the ball-and-socket joint permits rotation of the sensor housing in all spatial directions.
[0023] According to a further exemplary embodiment of the invention, the sensor housing comprises an automatic tracking unit for tilting the sensor housing so that a surface normal of the solar module points in the direction of the sun when the sensor housing is installed on a tank.
[0024] According to a further exemplary embodiment of the invention, the sensor housing comprises a GPS receiver for transmitting information relating to the actual position of the sun at the location of the sensor housing to the automatic tracking unit.
[0025] According to a further exemplary embodiment of the invention, the sensor housing comprises one or several brightness sensors for determining a direction from which sunlight shines into the solar module, and for transferring information relating to this direction to the automatic tracking unit.
[0026] According to a further exemplary embodiment of the invention, a field device for fill level measuring, limit measuring, pressure measuring and/or flow measuring is stated, which field device comprises a sensor housing described above and below.
[0027] According to a further exemplary embodiment of the invention, a modular system for producing (assembling) various field devices for fill level measuring, limit measuring, pressure measuring and/or flow measuring is stated, which modular system comprises a sensor housing with a solar module as described above and below.
[0028] According to a further exemplary embodiment of the invention, the modular system further comprises sensor electronics and a control module. In this arrangement the energy storage module is exchangeable through the sensor electronics. Likewise, the solar module is exchangeable through the control module. For example, both the solar module and the control module may thus be screwed onto the sensor housing. For example, either the energy storage module or the sensor electronics can be inserted in the first chamber.
[0029] According to a further exemplary embodiment of the invention, the use of a sensor housing, described above and below, in a field device for measuring the fill level, the limit, the pressure and/or the flow, is stated.
[0030] Below, exemplary embodiments of the invention are described with reference to the figures.
BRIEF DESCRIPTION OF THE FIGURES
[0031] FIG. 1 shows a sensor housing with a solar module according to an exemplary embodiment of the invention.
[0032] FIG. 2A shows a perspective view of a solar module according to an exemplary embodiment of the invention.
[0033] FIG. 2B shows a perspective view of a solar module according to an exemplary embodiment of the invention.
[0034] FIG. 2C shows the underside of a solar module according to an exemplary embodiment of the invention.
[0035] FIG. 3 shows a perspective view of a housing body according to an exemplary embodiment of the invention.
[0036] FIG. 4 shows a cross-sectional view of a sensor housing according to an exemplary embodiment of the invention.
[0037] FIG. 5 shows a cross-sectional view of a sensor housing according to a further exemplary embodiment of the invention.
[0038] FIG. 6 shows a cross-sectional view of a sensor housing and of a fill level sensor according to a further exemplary embodiment of the invention.
[0039] FIG. 7 shows a cross-sectional view of a sensor housing and of a field device according to a further exemplary embodiment of the invention.
[0040] FIG. 8 shows a cross-sectional illustration of a sensor housing and of a field device according to a further exemplary embodiment of the invention.
[0041] FIG. 9 shows a cross-sectional view of a sensor housing and of a field device according to a further exemplary embodiment of the invention.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0042] The illustrations in the figures are diagrammatic and not to scale.
[0043] In the following description of the figures the same reference characters are used for identical or similar elements.
[0044] FIG. 1 shows a sensor housing 100 according to an exemplary embodiment of the invention. The sensor housing comprises a first and a second chamber, each of which may be accessed through a cover 101 , 102 .
[0045] In the cover 101 there is a solar module which together with the cover 101 may be placed on top of the housing and thus on top of the first chamber. The second cover 102 may be screwed onto the second chamber, in which, for example, a measured-value transmission module for transmitting measured values and for receiving parameterizing data is located.
[0046] The sensor housing 100 comprises a mounting connection 105 with a receiver for a ball-and-socket joint 107 . The ball-and-socket joint 107 is affixed to a mounting plate 108 that can, for example, be affixed to the tank or form part of the tank.
[0047] Furthermore, a locking mechanism 106 is provided, as well as a locking action of the mounting connection to the ball-and-socket joint 107 .
[0048] Furthermore, a motor or drive 111 is provided, which is controlled by way of a control device (for example a CPU) 112 , and which can pivot the sensor housing on the ball-and-socket joint. In this way an automatic tracking unit is provided, which makes it possible for the sensor housing to always be optimally aligned relative to the sun. To this effect an optical detector 114 may also be provided, which is connected to the control device 112 and which measures the position of the sun. The detector 114 can, for example, also be affixed to the solar module. Moreover (as an alternative or in addition) a satellite navigation receiver 113 can be provided, which by means of its internal clock and if applicable the positioning data received can determine the current position of the sun at the location of installation, so that tracking is controlled automatically.
[0049] The arrows 109 , 110 show that the sensor housing 100 may be swivelled in various directions.
[0050] On the housing body 115 there is an antenna interface 104 , to which an antenna 103 can be connected. Furthermore, an interface 116 is provided, to which a sensor (for example a fill-level radar sensor or an ultrasound sensor, a limit sensor, a pressure measuring sensor or a flow sensor) can be connected.
[0051] FIG. 2A shows a solar module 200 which is integrated in the cover 101 (see FIG. 1 ). The solar module 200 comprises a housing 201 as well as one or several solar cells 202 . In addition, status LEDs and one or several control keys can be provided.
[0052] FIG. 2B shows a further embodiment of such a solar module 200 .
[0053] FIG. 2C shows the back of the solar module 200 . The illustration shows a group of 4×4 sliding contacts 203 , 204 , 205 , 206 . By means of these sliding contacts it is possible to attach the solar module at at least four different positions (0 degrees, 90 degrees, 180 degrees, 270 degrees) to the housing body, and to electrically connect the energy storage device. A resolution of the sliding contacts that is finer than 90 degrees per contact is also possible in order to achieve still more precise alignment to the sun.
[0054] For this purpose the housing body comprises four corresponding contact pins that are spring-loaded and that are arranged in a row, corresponding to the indicating and adjustment module PLICSCOM made by VEGA. In other words, the connection between the solar module and the energy storage module (for example in the form of an accumulator pack) takes place as is the case with PLICSCOM.
[0055] Two of the four contacts are used to transmit energy from the solar module to the energy storage device (e.g. the accumulator in the first chamber). The further two contacts can be used in order to display information about the accumulator state on the solar module, e.g. by pressing a button on a status display (e.g. bar LEDs). This makes possible communication between the accumulator electronics (protective circuit with intelligent charging) and the solar module.
[0056] FIG. 3 shows a three-dimensional view of a housing body 115 with a first chamber 401 and a second chamber 402 . The front regions of the two chambers 401 and 402 are cylindrical in shape, wherein the cylinder axes of the two chambers are perpendicular relative to one another. This results in an essentially L-shaped design of the housing body 115 .
[0057] As further shown in FIG. 3 , the external walls of the chambers 401 and 402 , which at the same time form sections of the external wall of the housing body 115 , may be reinforced by means of ribs 16 . In the chamber 401 a measuring-value transmission module 407 is arranged. Furthermore, the housing body 115 comprises an antenna connection 20 , a supply connection 22 and a control connection 24 or sensor supply connection 24 .
[0058] The sensor supply connection 24 of the housing body 115 is suitable for connection to a 4-20 mA two-conductor loop with or without a Hart bus, to a Profibus PA or to a Foundation Fieldbus (FF).
[0059] The supply connection 22 can be connected to a voltage supply of between 4.8 V and 40 V DC.
[0060] The housing body 115 comprises a thread 26 for the second chamber 402 , and a thread 28 for the first chamber 401 , by means of which the two chambers 401 , 402 can be closed with respective covers, wherein one cover can comprise the solar module. At the end of the thread 26 , 28 there is an O-ring 30 or 32 that makes it possible to close the chamber 14 , 16 so that it is waterproof. The threads 26 , 28 are identical in design, so that covers of an identical design can be used to close the two chambers 401 , 402 .
[0061] FIGS. 4 to 9 show cross-sectional views of a sensor housing in various configurations. It should be noted that all the configurations shown in FIGS. 4 to 9 can also be provided by a multifunctional sensor housing, in which the corresponding interfaces are provided. It should be noted that the embodiments shown in FIGS. 4 , 5 , 8 and 9 in combination with the solar module require corresponding dimensioning, or a corresponding capacity, of the solar module. However, an effective energy saving circuit, for example as disclosed in this description, can also make it possible to use relatively small solar modules.
[0062] FIG. 4 shows a sensor housing 100 (in other words a housing body 115 with corresponding installations and tops (e.g. covers 101 , 102 ) and connections (e.g. interface 116 )), which sensor housing 100 comprises a first chamber 401 and a second chamber 402 . The first chamber 401 houses the sensor electronics 406 , while the second chamber 402 houses a measured-value transmission module 407 for the transmission, either with or without cables, of measured values. For wireless transmission of measured values an antenna is provided (see for example FIG. 1 ). For wire-bound data transmission and energy supply a two-conductor loop 403 is provided, to which the measured-value transmission module 407 is connected.
[0063] The measured-value transmission module 407 is connected to the sensor electronics 406 in the first chamber by way of two conductors 405 . The energy supply to the sensor electronics takes place by way of these two conductors 405 . By way of the lines 404 , data is exchanged between the sensor electronics 406 and the measured-value transmission module 407 .
[0064] The communication line 404 is, for example, an I 2 C connection.
[0065] FIG. 5 shows a sensor housing 100 with sensor electronics 406 and a measured-value transmission module 407 in the two chambers. On the one hand the transmission module 402 is connected to an external power supply by way of the two-conductor loop 403 . On the other hand the sensor electronics 406 are also connected to an external power supply by way of the two conductors 501 .
[0066] In contrast to FIG. 4 , supply to the sensor takes place by way of the two-conductor loop 501 (e.g. HART, Profibus PA or Foundation Fieldbus). It is thus possible for the measured value of the sensor to be used by a control device for control or regulating purposes, and parallel to this the measured value can be transmitted by way of the transmission module 407 .
[0067] In the exemplary embodiment of FIG. 6 the first chamber 401 comprises an energy storage module 601 , for example in the form of an accumulator. The solar module (not shown in FIG. 6 ) is placed on top 602 of the first chamber 401 .
[0068] In this embodiment the sensor 600 (pressure sensor, fill level sensor, etc.) is arranged so as to be separate from the sensor housing (rather than in the first chamber 401 ). The sensor 600 is installed in a tank 603 which contains a product. By way of a corresponding data line 404 (for example I 2 C) and a supply line 501 , the sensor 600 is connected to the measured-value transmission module 402 . The location of installation of the sensor 600 and of the housing 100 with the measured-value transmission module 402 differs. This is necessary, for example, in those cases where the sensor 600 needs to be installed at a location that is unsuitable or inadequately suitable for GSM communication of the transmission module 402 . This variant can also be used if the energy is to be obtained by the system from an accumulator with a solar module connected to it.
[0069] FIG. 7 shows a further exemplary embodiment in which the sensor 600 is connected to a dedicated energy supply by way of the two conductors 501 . In other words, supply to the sensor 600 is by way of a loop (e.g. HART, Profibus PA or Foundation Fieldbus).
[0070] In the exemplary embodiments of FIGS. 8 and 9 an explosion protection barrier (ex barrier) 801 is integrated. The ex barrier ensures the necessary limitation of voltage and current so that the sensor supply through the measured-value transmission module 402 takes place in a manner that is intrinsically safe ( FIG. 8 ).
[0071] In this application the sensor housing 100 is always outside the ex region. This variant may be used for applications in which the sensor is located in a potentially explosive zone, and the measured values from this sensor are to be transmitted by way of the measured-value transmission module 402 .
[0072] In the exemplary embodiment of FIG. 9 sensor supply is by way of the loop 501 . This variant may thus be retrofitted to an existing installation.
[0073] The energy storage module 601 may house charge- and protection electronics. The solar module 200 may only house reverse polarity protection.
[0074] According to one aspect of the invention, the solar module may be oriented (in the direction of South in the northern hemisphere, or in the direction of the sun). This may take place by way of a ball-and-socket head at the base of the housing. Alignment may also be automatic. To this effect it is possible, for example, to provide a GPS receiver with a clock. Orientation by way of brightness sensors is also possible. Automatic orientation is associated with an advantage in that more energy is obtained, and in that at an inclination relative to horizontal (the ground) the system is less prone to dirt build-up.
[0075] If automatic tracking is provided, there is no need to provide a locking mechanism 106 (see FIG. 1 ). The adjustment mechanism is located in the holder (mounting connection 105 ). The device can be swivelled in all directions (up to the maximum tilt angle).
[0076] In addition, it should be pointed out that “comprising” does not exclude other elements or steps, and “a” or “one” does not exclude a plural number. Furthermore, it should be pointed out that characteristics or steps which have been described with reference to one of the above exemplary embodiments can also be used in combination with other characteristics or steps of other exemplary embodiments described above. Reference characters in the claims are not to be interpreted as limitations. | A sensor housing for a field device includes a housing body and a solar module that may be put in place and removed. The solar module supplies the field device with electrical energy and may be placed on top of the housing body at various angles of rotation, as a result of which at the same time an electrical contact between the solar module and an energy storage device is provided. | 8 |
BACKGROUND
The invention relates to a jet regulator having a jet regulator housing which has, on its outlet face side, a plurality of through-holes, having an inlay part which is inserted into the housing interior of the jet regulator housing as far as the outlet face side and which, on a base element, has a plurality of hose-like spray nozzles comprised of soft elastic material, which spray nozzles extend through in each case one outlet-face-side through-hole of the jet regulator housing and project with their free spray nozzle end region beyond the outlet face side of the jet regulator, and having an insert part which is inserted in and/or projects into the housing interior, between which insert part and the outlet face side the inlay part is secured in position in the axial direction.
A jet regulator of the type mentioned in the introduction, having a jet regulator housing which has, on its outlet face side, a plurality of through-holes, is already-known from DE 44 36 193 A1. The already-known jet regulator is assigned an inlay part which is inserted into the housing interior of the jet regulator housing as far as the outlet face side and which has a plurality of hose-like spray nozzles comprised of soft elastic material, which spray nozzles extend through in each case one outlet-face-side through-hole of the jet regulator housing. The spray nozzles which extend through in each case one outlet-face-side through-hole project with their free spray nozzle end region beyond the outlet face side of the jet regulator in such a way that said projecting spray nozzle ends can be deformed by a user running their hand over them, such that any limescale encrustations etc. can be easily removed. To be able to secure the disk-shaped inlay part, which has the spray nozzles, in the jet regulator housing, an inflow-side component which is for example in the form of a perforated plate with integrally formed flow chambers is pressed with its downstream face sides against the inlay part, and sealed off, as an outlet mouthpiece including within it the already-known jet regulator is screwed into the outlet fitting, such that the water can emerge only through the spray nozzles. However, as long as the already-known jet regulator is not situated in the outlet mouthpiece and as long as the outlet mouthpiece is not screwed onto the outlet fitting, the individual constituent parts of the already-known jet regulator are merely placed relatively loosely into one another and can easily become detached from one another during storage, transport or assembly. DE 44 36 193 A1 therefore also proposes that the inlay part which has the spray nozzles not be formed as a separate disk, but that rather the inlay part be molded as a composite material directly onto the jet regulator housing, which however entails significantly increased production outlay.
Already-known from DE 101 15 639 A1 is a jet regulator which has a substantially pot-shaped jet regulator housing, into the housing interior of which can be inserted an insert part which is in the form of a device, comprised of a dimensionally stable thermoplastic, for mixing water with air. The jet regulator housing of the already-known jet regulator has a housing base which is formed integrally on the jet regulator housing. On the housing base there are provided throughflow openings which are bordered and separated from one another by jet delimiting walls arranged parallel to the flow direction. On the water outlet end of said jet delimiting walls there is integrally formed a surface comprised of elastic plastic, which surface can be moved back and forth to such a considerable extent that even limescale deposits which project further inward can be mechanically detached.
The jet regulator housing of the already-known jet regulator is in the form of a multi-component injection molded part in order to be able to integrally form the soft elastic plastic surface on the water outlet end of the jet delimiting walls. However, the production of such a filigree jet regulator housing formed as a multi-component injection molded part requires a complex injection molding die, the construction, manufacture and/or maintenance of which involves considerable outlay.
Already-known from DE 44 36 193 A1 is a jet regulator designed for connecting to a sanitary outlet fitting, which jet regulator has an inflow-side jet splitter device and at least one outflow-side installation part for jet preparation. The already-known jet regulator has an adapter part, which can be connected to the outlet fitting, and an insert part, which can be connected to and separated from the adapter part without tools via a quick-release connection by means of an axial insertion or release movement, in which insert part the at least one installation part is inserted. The at least one installation part is thus accommodated in a secured manner in the housing interior between the inflow-side adapter part and the insert part which is provided at the outflow side and which can be detachably latched to the adapter part.
An inlay part which is inserted into the housing interior of the jet regulator housing as far as the outlet face side and which has a plurality of hose-like spray nozzles comprised of soft elastic material is by contrast not provided in DE 44 36 193 A1. Furthermore, the installation part constitutes an outflow-side component which is held in a detachably latchable manner on the jet regulator housing.
Already-known from DE 101 62 662 A1 is a jet regulator which can be mounted on a sanitary outlet fitting by means of an outlet mouthpiece. The already-known jet regulator has a jet regulator housing which can be inserted into the outlet mouthpiece and whose outlet end side is in the form of a perforated plate. The holes which are provided in the outlet face side which is in the form of a perforated plate, which holes are arranged in a hole ring, are narrowed in terms of their hole outlet cross section on the radially inner or outer hole side in relation to the hole ring by a stepped projection, which extends over a segment of the hole cross section, in such a way that the thereby diverted water jets emerge as a soft, slightly conical overall jet. Further components of the already-known jet regulator are not described in any more detail in DE 101 62 662 A1.
SUMMARY
It is therefore the object to provide a jet regulator of the type mentioned in the introduction, the production of which requires less outlay even in the case of relatively low production quantities, without the risk of leakage flows which influence the jet appearance of the jet regulator.
The object is achieved according to the invention, in the case of the jet regulator of the type mentioned in the introduction, in particular by means of the features of the present invention.
The jet regulator according to the invention has a jet regulator housing which has, on its outlet face side, a plurality of through-holes. The jet regulator according to the invention also has a separate inlay part which is inserted into the housing interior of the jet regulator housing as far as the outlet face side. The inlay part has a base element on which there are provided a plurality of hose-like spray nozzles comprised of soft elastic material, which spray nozzles extend through in each case one outlet-face-side through-hole of the jet regulator housing and project with their free spray nozzle end region beyond the outlet face side of the jet regulator. The inlay part also has a circumferential edge region which projects counter to the inflow direction and which is designed as a sealing edge which bears sealingly against the housing inner circumference. Since the inlay part bears sealingly with its circumferential edge region, which projects counter to the inflow direction, against the housing inner circumference, the water flowing through the jet regulator according to the invention can emerge only through the spray nozzles, and undesired leakage flows between the inner circumference of the jet regulator housing on the one hand and the outer circumference of the inlay part on the other hand are prevented. To secure the separate inlay part, which is inserted into the housing interior, in the axial direction of the jet regulator and hold down said inlay part in the housing interior on the outlet face side, an insert part is provided which is likewise inserted into the housing interior and/or projects into the housing interior, between which insert part and the outlet face side the inlay part is secured in position in the axial direction. In the jet regulator according to the invention, the jet regulator housing on the one hand and the outlet-side spray nozzles on the other hand need not be produced as multi-component injection-molded parts in a complex injection molding die, it rather also being possible for the components of the jet regulator according to the invention to be produced separately from one another in separate and relatively simple injection molding dies. Even though the separately produced components of the jet regulator according to the invention are inserted into one another merely in an easily detachable manner, the inlay part with its soft elastic spray nozzles, which are also subjected to not possibly inconsiderable manual exertion of force for the detachment of limescale deposits, is arranged secured in position in the housing interior in such a way that there is no risk of functionally detrimental relative displacements of the components assembled to form the jet regulator according to the invention.
Since the jet regulator according to the invention has an inflow-side component which is held in a releasably latchable manner on the jet regulator housing or on a housing part of the jet regulator housing, and since the insert part is itself secured in the housing interior of the jet regulator housing by the inflow-side component, the inlay insert parts situated in the housing interior of the jet regulator housing are securely and captively accommodated therein at all times. It is thus necessary for the latching connection between the inflow-side component and the jet regulator housing, or the housing part of the jet regulator housing, to be released before the insert part and the inlay part, which is secured in the housing interior in the axial direction by the insert part, can be removed.
It is advantageous for the base element of the inlay part to be of plate-shaped or disk-shaped form.
A preferred embodiment of the invention provides that the inlay part has a pot-shaped sub-region, and that the base element of the inlay part forms the pot base. In this embodiment, the inlay part has a pot-shaped sub-region which can also be inserted, positioned correctly in the radial direction, into the jet regulator housing. Here, the pot base of the pot-shaped sub-region forms the base element which, in the housing interior, bears against the outlet face side and on which the hose-like spray nozzles are provided.
In order that the individual jets emerge visibly separated from one another from the spray nozzles of the jet regulator according to the invention, it is advantageous for the spray nozzles to be provided on at least one circular path arranged preferably concentrically around the jet regulator longitudinal axis.
Here, it is provided in one preferred embodiment of the invention that the outlet face side of the jet regulator housing has a hole-free or non-perforated central region and that in particular no spray nozzles are provided in said central region.
In order that the water flowing into the jet regulator according to the invention can be substantially uniformly split up and distributed to the individual spray nozzles, it is expedient if there is inserted into the jet regulator housing a diffuser or a distributor which breaks down the inflowing water flow into a multiplicity of partial flows distributed over the circumference of the diffuser or of the distributor.
Here, it is provided in one preferred embodiment of the invention that the diffuser or the distributor has an annular wall, in which annular wall there are provided a plurality of throughflow openings which are distributed over the circumference of the annular wall and from which at least one duct and preferably one annular duct leads to the spray nozzles.
In order that the individual jets emerging from the spray nozzles of the jet regulator according to the invention can flow out as soft individual jets, and in order that the individual jets are for this purpose slowed to an adequate extent, it is expedient for the distributor to have a preferably central and in particular pot-shaped overflow, the overflow openings of which form the throughflow openings.
It is provided in one preferred embodiment of the invention that the distributor forms the insert part which secures the inlay part in the axial direction.
It is provided in a further embodiment of the invention that the jet regulator housing has at least two housing parts which can be releasably latched to one another and of which the inflow-side housing part forms a component, which secures the insert part in the housing interior, of the jet regulator. Here, it is particularly advantageous for the insert part to be in the form of a hold-down sleeve which is provided between the inflow-side housing part and the inlay part.
To be able to fasten the jet regulator according to the invention to the water outlet of a sanitary outlet fitting, it is provided in one embodiment of the invention that the jet regulator has, on its jet regulator housing, an annular flange by means of which the jet regulator rests on an annular shoulder provided at the inside in an outlet mouthpiece or an intermediate bracket. By means of said outlet mouthpiece, the jet regulator inserted into the mouthpiece can be held on the water outlet of a sanitary outlet fitting.
By contrast, it is provided in another embodiment of the invention that the jet regulator bears, on its jet regulator housing, an external thread by means of which the jet regulator can be screwed into an internal thread provided at the inside on the water outlet of a sanitary outlet fitting. In this embodiment, the jet regulator has, on its jet regulator housing, an external thread by means of which the jet regulator of the jet regulator according to the invention can be screwed into an internal thread provided at the inside on the water outlet of the sanitary outlet fitting, in such a way that the jet regulator is accommodated, over a significant part of its longitudinal extent, in a protected manner in the water outlet of the outlet fitting, without the need for an additional outlet mouthpiece.
It is provided in one preferred refinement of the invention that the jet regulator is assigned a plurality of insert parts which can be selectively inserted into the jet regulator housing, and that one of said inlay parts closes off individual through-holes of the jet regulator housing in order to reduce the throughflow capacity. It is thus possible for one jet regulator to be assigned multiple inlay parts, of which one inlay part extends with its integrally formed hose-like spray nozzles for example through all of the outlet-face-side through-holes of the jet regulator housing in order to attain as high a throughflow capacity as possible, and of which another inlay part has, in relation thereto, a reduced number of spray nozzles which extend through only a correspondingly reduced number of through-holes in the jet regulator housing, while said inlay part sealingly closes off the other through-holes in the jet regulator housing.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of the invention will emerge from the following description of preferred exemplary embodiments in conjunction with the drawings and the subclaims. Here, the individual features may be realized, and essential to the invention, in each case individually or in combination with one another.
In the drawings:
FIG. 1 shows, in one view, a jet regulator which has a plurality of projecting spray nozzles on the outlet face side of its jet regulator housing, wherein in the housing interior of the jet regulator housing there is provided a distributor (not illustrated in any more detail in FIG. 1 ) which divides the inflowing water into a multiplicity of partial flows flowing to the spray nozzles,
FIG. 2 shows the jet regulator from FIG. 1 in a longitudinal section,
FIG. 3 shows the jet regulator from FIGS. 1 and 2 in a perspective view from below,
FIG. 4 shows the jet regulator from FIGS. 1 to 3 in a perspective partial longitudinal section,
FIG. 5 shows a jet regulator of similar design to that in FIGS. 1 to 4 , which jet regulator however has a diffuser (not shown in any more detail here) instead of a distributor in the housing interior of a jet regulator housing,
FIG. 6 shows the jet regulator from FIG. 5 in a longitudinal section,
FIG. 7 shows the jet regulator from FIGS. 5 and 6 in a perspective view from below,
FIG. 8 shows the jet regulator from FIGS. 5 to 7 in a perspective partial longitudinal section,
FIG. 9 shows a jet regulator in a plan view directed toward its inflow-side housing face side, which jet regulator bears on its jet regulator housing an external thread by means of which the jet regulator can be detachably screwed into an internal thread provided on the water outlet of a sanitary outlet fitting,
FIG. 10 shows the jet regulator from FIG. 9 in a longitudinal section through the section plane X-X from FIG. 9 ,
FIG. 11 shows the jet regulator from FIGS. 9 and 10 in a longitudinal section through section plane XI-XI from FIG. 9 ,
FIG. 12 shows the jet regulator from FIGS. 9 to 11 in a plan view of its outlet face side,
FIG. 13 shows the jet regulator from FIGS. 9 to 12 in a perspective plan view of its inflow-side end face,
FIG. 14 shows the jet regulator from FIGS. 9 and 13 in a perspective plan view of its outflow side,
FIG. 15 shows a significantly more compact jet regulator which is characterized by a comparatively short structural height and which likewise bears on its jet regulator housing an external thread by means of which the jet regulator can be detachably screwed into an internal thread provided on the water outlet of a sanitary outlet fitting, wherein on an elastic inlay part of the jet regulator there are integrally formed only a reduced number of spray nozzles which extend through a corresponding number of through-holes on the outlet face side of the jet regulator housing, while the inlay part sealingly closes off those through-holes of the jet regulator housing which are arranged on an inner circular path,
FIG. 16 shows the jet regulator from FIG. 15 in a longitudinal section through section plane XVI-XVI in FIG. 15 ,
FIG. 17 shows the jet regulator from FIGS. 15 and 16 in a perspective view of its outlet face side.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 17 illustrate different embodiments 1 , 5 , 30 , 31 of a jet regulator from which the water should emerge as a shower-like water jet formed from a multiplicity of individual jets. The substantially pot-shaped jet regulator housing 2 has, on its outlet face side 3 which forms the pot base of the pot-shaped jet regulator housing 2 , a plurality of through-holes 4 .
The jet regulators 1 , 5 , 30 and 31 are assigned a separate inlay part 6 which is inserted into the housing interior as far as the outlet face side 3 . The inlay part 6 has a plurality of hose-like spray nozzles 7 which are designed to generate a multiplicity of preferably visibly separately emerging individual jets. The spray nozzles 7 extend through in each case one outlet-face-side through-hole 4 of the jet regulator housing 2 and project with their free spray nozzle end region beyond the outlet face side 3 of the jet regulator 1 , 5 , 30 , 31 .
The already-known jet regulators 1 , 5 , 30 , 31 also have an insert part 8 which is inserted into the housing interior, between which insert part and the outlet face side 3 the inlay part 6 is secured in position in the axial direction.
In the jet regulators 1 , 5 , 30 , 31 illustrated here, the jet regulator housing 2 on the one hand and the outlet-side spray nozzles 7 on the other hand need not be produced as a multi-component injection-molded part in a complex injection molding die; it is rather also possible for said components to be produced separately from one another in separate and relatively simple injection molding dies. Even though the separately produced components 2 , 7 of the jet regulators 1 , 5 , 30 , 31 are inserted into one another merely in an easily detachable manner, the inlay part 6 with its soft elastic spray nozzles 7 , which are also subjected to not possibly inconsiderable manual exertion of force for the detachment of limescale deposits, is arranged secured in position in the housing interior in such a way that there is no risk of functionally detrimental relative displacements of the components assembled to form the jet regulators 1 , 5 , 30 , 31 .
From the longitudinal sections in FIGS. 2, 4, 6, 8, 10, 11 and 16 , it is clear that the inlay part 6 of the jet regulators 1 , 5 , 30 , 31 has a disk-shaped base element 9 on which the hose-like spray nozzles 7 are held. Here, the inlay part 6 has in this case a pot-shaped sub-region whose pot base forms the base element 9 with the spray nozzles 7 .
The in this case pot-shaped inlay part 6 of the jet regulators 1 , 5 , 30 , 31 has a circumferential edge region 10 which projects counter to the inflow direction and which is designed as a sealing edge which bears sealingly against the housing inner circumference. For this purpose, the circumferential edge region 10 which projects counter to the inflow direction is oriented obliquely outward such that said circumferential edge region practically forms a lip seal which bears sealingly against the housing inner circumference of the jet regulator housing 2 . Since the circumferential edge region 10 of the inlay part 6 bears sealingly against the inner circumference of the jet regulator housing 2 , undesired leakage flows between the inlay part 6 and the inner circumference of the jet regulator housing 2 are prevented.
It can be seen from the perspective views from below in FIGS. 3, 7, 14 and 17 that the spray nozzles 7 provided on the jet regulators 1 , 5 , 30 , 31 are provided on circular paths arranged concentrically around the jet regulator longitudinal axis. Here, a non-perforated central region 11 which is not equipped with spray nozzles 7 is provided on the outlet face side of the jet regulator housing 2 .
Positioned upstream of the jet regulators 1 , 5 , 30 , 31 is in each case one flow rate regulator 12 which limits the maximum throughflow capacity per unit of time to a pressure-independent maximum value. The flow rate regulator 12 is connected in a latchable or similarly detachable manner to the jet regulators 1 , 5 , 30 , 31 on the inflow side of the latter. In order that the function of the flow rate regulators 12 and of the jet regulators 1 , 5 , 30 , 31 positioned downstream thereof at the outflow side cannot be impaired by dirt particles possibly entrained in the water, in each case one upstream screen 13 is positioned upstream of the flow rate regulators 12 and of the jet regulators 1 , 5 , 30 , 31 , which upstream screen is connected likewise in a detachable manner to the flow rate regulator 12 and to the respective jet regulator 1 , 5 , 30 , 31 .
Into the jet regulator housing 2 of the jet regulators 1 , 5 , 30 , 31 there is provided a diffuser 14 (cf. FIGS. 5 to 8, 15 to 17 ) or a distributor 15 (cf. FIGS. 1 to 4, 9 to 14 ) which breaks the inflowing water flow into a multiplicity of partial flows distributed over the circumference of the diffuser 14 or distributor 15 . For this purpose, the components 14 , 15 have an annular wall 16 in which are provided a plurality of throughflow openings 17 distributed preferably uniformly over the circumference of the annular wall 16 . An annular duct 18 leads from the throughflow openings 17 to the spray nozzles 7 of the inlay part 6 .
The distributor 15 of the jet regulator 1 , 30 shown in FIGS. 1 to 4 and 9 to 14 has a central overflow 19 which is of substantially pot-shaped form and whose overflow openings form the throughflow openings 17 . Here, the distributor 15 forms the insert part 8 which secures the inlay part 6 in the axial direction. The distributor 15 has for this purpose an outer annular wall 20 which surrounds the pot-shaped overflow 19 with a spacing and which is connected to said overflow via an inflow-side, annularly encircling perforated or connecting plate 21 which is arranged approximately in a radial plane. The outer annular wall 20 of the distributor 15 rests with its outflow-side face end region on an annular shoulder 22 of the inlay part 6 in such a way that the inlay part 6 is secured in position in the jet regulator 1 , 30 so as to be immovable in the axial direction.
It is clear from a comparison of FIGS. 1 to 4, 5 to 8, 9 to 14 and 15 to 17 that each jet regulator 1 , 5 , 30 , 31 has an inflow-side component 23 which is held in a detachably latchable manner on the jet regulator housing 2 or on a housing part 24 of the jet regulator 1 , 5 , 30 , 31 . Here, the insert part 8 which secures the inlay part 6 in the axial direction is itself secured in the housing interior of the jet regulator housing 2 by the inflow-side component 23 .
While it is the case in the jet regulators 1 , 30 , 31 illustrated in FIGS. 1 to 4 and 9 to 17 that the flow rate regulator 12 forms the component 23 that can be detachably latched in the inflow-side region of the jet regulator 1 and which bears with an annular wall 25 against the distributor 15 or the diffuser 14 , the jet regulator housing 2 of the jet regulator 5 shown in FIGS. 5 to 8 has two housing parts 24 , 26 , the inflow-side housing part 24 of which forms a component 23 , which secures the insert part 8 in the housing interior, of the jet regulator 5 . The insert part 8 of the jet regulator 5 is in this case formed as a hold-down sleeve which tapers in the inflow direction and which bears at the inflow side against the adjacent face end region of the housing part 24 and at the outflow side against an annular shoulder 22 of the inlay part 6 . It can be seen from the longitudinal section in FIG. 6 that that duct portion of the annular duct 18 which is formed between the diffuser 14 and the adjacent inner circumference of the housing part 24 tapers such that, in said region, a vacuum is generated which can be used for sucking air into the housing interior of the jet regulator housing 2 , wherein it is intended for the air to be mixed with the water flowing through.
The jet regulators 1 , 5 have a jet regulator housing 2 which can be inserted into an outlet mouthpiece (not illustrated in any more detail here) which can be mounted on the outlet end of a sanitary outlet fitting. For this purpose, the jet regulators 1 , 5 have, on their jet regulator housing 2 , an annular flange or annular shoulder 32 by means of which the jet regulator 1 , 5 rests on an annular shoulder provided at the inside in the outlet mouthpiece.
The jet regulator 30 also has an annular flange or annular shoulder 32 on the housing outer circumference of its jet regulator housing 2 . The jet regulator 30 can be inserted into an intermediate bracket 36 from the inflow side of the latter until the annular flange or annular shoulder 32 of the jet regulator comes to rest on an annular shoulder provided on the inner circumference of the sleeve-shaped intermediate bracket or on the inflow-side face edge of the intermediate bracket 36 . The jet regulator 30 can be fastened in the water outlet of a sanitary outlet fitting by means of the intermediate bracket 36 . For this purpose, the sleeve-shaped intermediate bracket 36 has, on its outer circumference, an external thread 37 by means of which the intermediate bracket 36 can be detachably screwed into an internal thread on the water outlet of a sanitary outlet fitting.
By contrast, the jet regulator 31 bears on its jet regulator housing 2 an external thread 33 by means of which the jet regulator 31 can be screwed into an internal thread provided at the inside on the water outlet of an outlet fitting (likewise not illustrated here).
While the inlay parts 6 of the jet regulators 1 , 5 , 30 have provided therein a corresponding number of spray nozzles 7 such that said spray nozzles 7 can all extend through through-holes 4 provided in the jet regulator housing 2 , the jet regulator 31 in FIGS. 15 to 17 has in relation thereto a reduced number of spray nozzles 7 on its inlay part 6 , wherein the inlay part 6 of the jet regulator 31 sealingly closes off those through-holes 4 of the jet regulator housing 2 which are arranged on the inner circular path in order to reduce the throughflow capacity. To be able to sealingly close off those through-holes 4 of the jet regulator housing 2 which are arranged on the inner circular path, spray-nozzle-shaped studs 34 are in this case provided on the inlay part 17 , which studs extend through and sealingly close off the through-holes 4 provided on the inner circular path.
It is clear from FIGS. 15 to 17 that the jet regulators illustrated here may also be part of a modular jet regulator construction kit or system. Here, the jet regulator 31 may also be assigned a plurality of inlay parts 6 which can be selectively inserted into the jet regulator housing 2 and of which the inlay part 6 illustrated merely by way of an example in FIGS. 15 to 17 closes off individual through-holes 4 of the jet regulator housing 2 in order to reduce the throughflow capacity. The jet regulator 31 shown in FIGS. 15 to 17 is designed for a low throughflow capacity. Since the through-holes 4 arranged on the inner circular path are closed off by the studs 34 which project from the inlay part 6 , the water can emerge only through the spray nozzles 7 arranged on the outer circular path. The advantage of the jet regulator design shown in FIGS. 15 to 17 is that only the inlay part 6 and therefore only a single component must be changed in order to adapt the jet regulator 31 to a different throughflow capacity. It is self-evident that the inlay part 6 shown in FIGS. 15 to 17 may also be used in jet regulator designs such as are shown in FIGS. 1 to 14 . | A jet regulator ( 1 ) including a two-part jet-regulator housing ( 2 ), the outlet end face ( 3 ) of which has multiple passages ( 4 ), a pot-shaped inlay ( 6 ) that is inserted into the housing interior ( 2 ) until it reaches the outlet end face ( 3 ) and that has multiple tubular spray nozzles ( 7 ), each of which penetrates a passage ( 4 ) on the outlet end face of the jet regulator housing ( 2 ) and the free spray-nozzle region of which protrudes beyond the outlet end face ( 3 ) of the jet regulator ( 1, 5 ). The jet regulator also includes an insert ( 8 ) that is inserted in the housing interior and the position of the inlay part ( 6 ) is secured in an axial direction between the insert, the second housing part and the outlet end face ( 3 ). | 4 |
FIELD OF THE INVENTION
Epidural needles for placing electrode catheters for spinal cord stimulation.
BACKGROUND
Spinal cord stimulation (SCS) with electrical pulses is an accepted technique to treat certain patients having symptoms or conditions such as chronic pain, Parkinson's Disease, incontinence and epilepsy, among others. The treatment involves delivery of electrical pulses at selected locations along the spinal cord by electrode leads that are implanted within and extend along the epidural space of the spine. When such treatment is beneficial, the patient will experience a sensation (paresthesia) as the discomfort or other symptom is relieved. Such leads may be temporarily or permanently implanted. An important part of the procedure is the placement of the lead to locate the electrodes at its distal end at precisely the right location to affect the desired nerves. That involves adjustment in the position of the lead and monitoring feedback from the patient to determine the best position for the lead. When the best position is determined the lead is fixed in place. Lead placement also may be conducted under fluoroscopic visualization.
Leads may be placed surgically or in a less invasive, percutaneous, procedure. The percutaneous procedure involves insertion of a hollow needle into the epidural space so that the lead can be advanced through the lumen of the needle and then longitudinally along the dura of the spinal cord to the intended region of the spinal column. Typically, the position of the lead must be adjusted by advancing or retracting the lead through the needle and testing the effect of applying electrical pulses at various locations and with varying signals.
The leads typically are constructed to include a flexible elongate polymeric shaft with a plurality of electrodes mounted, at spaced locations, on the shaft. The electrodes are connected to wires that extend through the catheter to the proximal end of the catheter where they may be connected to a pulse generator. Some leads also may be placed with the aid of a stylet that is disposed within a lumen of the lead and can be manipulated by the physician
Among the difficulties with placement of epidural SCS leads is that the transitions along the outer surface of the lead from polymer to electrode to polymer, etc. may have some irregularities that sometimes results in the transition regions of the catheter becoming caught or snagged on an edge of the needle, possibly damaging the catheter. This is particularly troublesome as the physician is attempting to adjust the position of the lead by advancing or retracting the lead through the needle. Although the needle may be provided with an elongate bevel at its distal end to enable the lead to bend at a relatively large radius to reduce snagging, it would be desirable, however, to provide additional means by which the advancement or retraction of the lead through the needle is made smooth and with still further reduced risk of catching. It is among the objects of at least the invention to provide improvements to that end.
SUMMARY OF THE INVENTION
The needle is provided with a selectively electropolished edge in the heel portion of the bevel. The polished edge is the proximal arcuate inner edge of the needle lumen where it transitions into the bevel. The inner edge is electropolished to form a radius over which the transitional regions of the catheter can pass without snagging or catching. In the preferred embodiment, the radius is of the order of about 0.002 inch and is substantially uniform along the arc defined by the edge.
DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is an isometric illustration of the distal end of a needle having an elongate bevel;
FIGS. 1A-1C are illustrations of the needle as seen along the planes 1 A- 1 A, 1 B- 1 B and 1 C- 1 C of FIG. 1 ;
FIG. 2 is a somewhat diagrammatic illustration of a neurostimulation lead adapted to be placed through the needle into the epidural space and adjustably positioned along the spinal column;
FIG. 2A is an enlarged illustration of a transitional region between a crimped ring electrode and the polymeric body of the lead; and
FIG. 3 is a somewhat diagrammatic illustration of the arrangement for electropolishing portions of the needle.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 2 illustrates one type of catheter-like neurostimulation lead 10 adapted for placement within the epidural space. The lead 10 includes a flexible biocompatible polymeric body 12 and a plurality of electrodes 14 spaced longitudinally along the body. In the embodiment shown, the electrodes 14 and exposed segments 15 of the polymeric body 12 disposed between the electrodes may define an outer surface for the lead 10 having alternating bands of polymer and electrodes. The electrodes 14 , which may be platinum or other suitable biocompatible metal, are connected by wires extending internally within the polymeric body 12 to connectors at the proximal end of the lead where they may be connected to a signal generator (not shown) that may be implanted within or located externally of the patient.
FIG. 2A illustrates, in enlarged diagrammatic section, a portion of the lead 10 that includes the transition region 16 between an electrode 14 and an adjacent exposed portion 15 of the polymeric body 12 . It is not uncommon for such leads to have at least some transitional regions 16 that do not present an even surface. In some cases, this may be the result of deliberate design or, in others, due to manufacturing tolerances. For example, when the electrode bands are crimped onto the lead body, the body in the transition region may be compressed, leaving a slight depression 17 . The interruptions in the transitional regions 16 present a risk of a transitional region (e.g., at the edge 19 of an electrode 14 ) becoming caught on an edge of the introduction needle as the lead is withdrawn through the lumen of the needle, either during adjustment or placement of the lead. It would be desirable to provide a simple, inexpensive way to avoid this difficulty.
We have found that the risk of snagging of a neurostimulation lead during placement may be reduced significantly, and possibly eliminated, by electropolishing selected portions of the needle. As shown in FIGS. 1 and 1 A- 1 C, the needle 18 is formed from stainless steel hypodermic tubing 20 , for example, 14 gage to 22 gage. The tip 22 is elongated, having a long bevel 22 that may be of the order of about 0.2 to about 0.3 inch long with inner and outer edges 24 , 26 . The inner edge 24 of the bevel may be considered as having a pair of parallel, longitudinally extending sides 28 , a tip segment 30 and a semicircular heel segment 32 . The lumen-defining edge 34 of the heel segment 32 that results from the grinding of the bevel is susceptible to having burrs, irregular edges and the like that may become caught on a transitional region 16 of the lead 10 as the lead is manipulated through the needle. Typically, the manufacture of such needles involves abrasive blasting or wire EDM treatment of the tip to attempt to eliminate burrs or other irregularities resulting from the grinding of the tip. Other approaches involve the use of an abrasive cord that is threaded through the lumen of the needle and worked back and forth. These are relatively inefficient hand operations that may result in non-uniform surfaces and edges.
In accordance with the present invention, the heel region of the epidural needle is electropolished in a controlled manner, with the electropolishing process being focused on the heel of the bevel such that the inner edge 34 of the heel segment 32 is formed with a regular and uniform cross-sectional radius large enough to avoid catching on irregular transitional regions 16 of the neurostimulation lead 10 . We have found that electropolishing the edge 34 to a radius of at least about 0.002 inch is sufficient to materially reduce the risk of, and possibly avoid, adverse interference between the heel 32 and the outer surfaces of the lead.
FIG. 3 illustrates in diagrammatic side view the manner in which the selective electropolishing may be conducted. The needle 20 is held in a fixture, as is a wire-like electropolishing electrode 36 . The fixture supports the electrode (cathode) and needle in a relative orientation that will concentrate the energy applied between the electrode and the needle so that it is at its greatest intensity at the region of the heel segment 32 . The electrode preferably is configured and positioned to provide substantially uniform energy density along the inner edge of the heel 32 to obtain a substantially consistent electropolished radius along the arcuate edge 34 . The electrode should have a diameter no greater and, preferably, smaller than the inner diameter of the needle lumen to facilitate placement in close proximity to the heel. In a preferred embodiment, the tip of the electrode is directed toward the heel and preferably is held at a distance 38 between about 2 to about 3 millimeters from the heel 32 . The electrode should be contained within an insulative jacket 40 heat shrunk onto the electrode with approximately 0.1 inch of the electrode protruding distally beyond the end of the jacket. The wire cathode 36 may be formed from titanium or copper and, for example, for a fifteen gauge needle, a cathode of the order of about 0.047 inch diameter may be employed. The needle and the electrode are immersed within any suitable electropolishing fluid for use with the metal from which the hypotube is made, for example, 300 series stainless steel. The duration, voltages, electric current and the temperature and specific gravity of the electropolishing fluid may be varied and selected. We have found that these parameters can be varied such that the operation can be completed in approximately two and one-half minutes and results in a very smooth, regular radius extending along the length of the arcuate edge of the heel. A plurality of such fixtures may be provided to conduct the electropolishing of needles in batch quantities with substantially greater efficiency and uniformity of results than with the prior hand abrading techniques.
It should be understood that the foregoing description of the invention is intended merely to be illustrative and that variations may be employed within the scope of the claims and their equivalents. | An epidural needle for placement of a pain management electrode includes an elongated bevel having a heel segment defined by a proximal rounded inner edge in which the heel has an electropolished radius of at least about 0.002 inch extending substantially continuously along the inner edge that defines the heel; a method for fabricating the needle. | 0 |
[0001] This application is a Divisional of application Ser. No. 10/453,137, filed on Jun. 15, 2006, which is a divisional of application Ser. No. 10/952,836, filed on Sep. 30, 2004, and for which priority is claimed under 35 U.S.C § 120; and this application claims priority of application Ser. No. 093114660 filed in Taiwan, R.O.C. on May 24, 2004 under 35 U.S.C. § 119; the entire contents of all are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an outer suspension type lens shielding mask for a projection apparatus, and more particularly to a lens shielding mask mounted outside of a projection lens and designed for matching all kinds of aspect ratios of projection pictures to reduce the leaking of the diffusion light outside of tie picture.
[0004] 2. Description of Related Art
[0005] Diffusion light is yielded in a general projector when light is experienced a several reflection and projection after it is emitted from an optical engine. And, a contrast is lowered after the diffusion light is leaked out through the projection lens so that the quality of a dark scene is influenced when the projector is used on such as a home video picture playing.
[0006] Therefore, for lowering the darkness of the dark scenes of a motion picture in a projector to enhance the performance of contrast, an optical grating is always added in an optical engine system. But, not only needs it to add elements in entire optical engine or change a design but also helps it nothing for a currently existed projector model if the optical grating is added in the optical engine. Therefore, substantially, it is necessary to add an optical grating device without changing the internal structure of a current projector and increasing production cost.
SUMMARY OF THE INVENTION
[0007] The main object of the present invention is to provide an outer suspension type lens shielding mask for a projection apparatus, capable of being mounted outside of a projection lens and being designed to a static optical grating or adjustable optical grating matching with every kind of different aspect ratio of projection picture.
[0008] Another object of the present invention is to provide an outer suspension type lens shielding mask for a projection apparatus, capable of reducing production cost by elevating the picture quality from the outside of the projection apparatus without changing the design of an optical engine.
[0009] Still another object of the present invention is to provide an outer suspension type lens shielding mask for a projection apparatus, capable of avoiding bad shadow outside of a picture caused from diffraction light so as to improve the quality of sight amusement.
[0010] For attaining to the objects mentioned above, an outer suspension type lens shielding mask for a projection apparatus according to the present invention comprises a sheet body and a holding element, in which a rectangular hole is opened in the sheet body and the sheet body is combined with the holding element together for being fixed on a projection apparatus. Another outer suspension type lens shielding mask according to the present invention comprises a base plate, in which a rectangular hole is opened in the middle part thereof, upper and lower adjustable plates, installed behind the base plate and an open rectangular notch is respectively disposed at the middle parts of the upper and the lower adjustable plates, and an adjustment mechanism, consisting a plurality of connecting elements connected to the base plate and the upper and the lower adjustable plates for adjusting the relative positions of the upper and the lower adjustable plates on the base plate.
[0011] Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] 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 in which:
[0013] FIG. 1 is a prospective view, showing a lens shielding mask with a fixed type optical grating of a preferred embodiment according to the present invention;
[0014] FIGS. 2A and 2B are schematic views, showing a motion for mounting a lens shielding mask with a fixed type optical grating onto a projection apparatus;
[0015] FIG. 3 is an explosive view, showing a lens shielding mask with an adjustable optical grating of another preferred embodiment according to the present invention;
[0016] FIG. 4 is a cross sectional view, showing an assembled lens shielding mask with an adjustable optical grating of another embodiment according to the present invention;
[0017] FIG. 5 is a schematic view, showing a motion for mounting a lens shielding mask with a fixed type optical grating onto a projection apparatus;
[0018] FIG. 6 is an explosive view, showing a lens shielding mask with an adjustable optical grating of still another preferred embodiment according to the present invention; and
[0019] FIG. 7 is a cross sectional view, showing an assembled lens shielding mask with an adjustable optical grating of still another embodiment according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Please refer to FIG. 1 . FIG. 1 is a prospective view showing a lens shielding mask with a fixed type optical grating of a preferred embodiment according to the present invention. A lens shielding mask 10 with a static optical grating mainly comprises a circular disc type sheet body 101 made from an opaque material or a flat plate coated with an opaque material on the surface thereof and used for shielding diffraction light projected from a lens of a projector; the diameter thereof is approximately equal to the inner diameter of a outer frame in front of the lens of the projector as FIGS. 2A and 2B show. A rectangular hole 102 whose shape and location depend on the type of the lens is opened in the sheet body 101 Because the aspect of a general picture is 16:9, although the ratio of the length and the width of the rectangular hole is always fabricated to be 16.9, but it can also be fabricated to be 4:3 or even 2.35:1 for accommodating it to a different aspect ratio. The hole 102 is deviated from the center of the sheet body 101 according to the present invention. A plurality of clamping ears 103 are disposed around the circumference of the sheet body 101 . These clamping ears can be formed with the sheet body 101 into one body or combined with the sheet body 101 by means of adhesion or welding. The numbers and the locations of the clamping ears 103 are not particularly defined, only that a user can mount the lens filtering mask 10 conveniently on the outer frame of the lens of the projector is enough. In addition, a material such as fiber can be stuck on the circumference of the circular sheet body 101 for being taken as a clamping element to allow the sheet body to be engaged tightly in the outer frame of the lens.
[0021] The motion for mounting the lens filtering mask with a fixed type optical grating mentioned above can be seen in FIGS. 2A and 2B . A user only uses his fingers to clip the clamping ears 103 on the sheet body 101 and aims the mask at and then mounts it on the outer frame 3 outside of the lens 2 of the projector 1 . Thereafter, the fingers are again used to clip the lens filtering mask 10 to rotate the sheet body 101 until the rectangular hole is aligned with a formation zone of image after the lens shielding mask 10 is mounted on the outer frame 3 .
[0022] Next, please refer to FIGS. 3 and 4 . FIGS. 3 and 4 are explosive and cross sectional views respectively showing parts and after-assembly structure of a lens shielding mask with an adjustable optical grating of another preferred embodiment according to the present invention. A lens filtering mask 20 with an adjustable optical grating comprises a base plate 201 and upper and lower adjusting plates 202 and 203 . A sleeve 2011 is disposed at each corner of the base plate 201 and a rectangular hole 204 whose shape and location is disposed depending oil the aspect of a lens is opened in the base plate 201 ; according to the present invention, the hole is symmetrical to a center line in the direction of the width of the base plate (i.e. line A-A′ in FIG. 3 ), and the center point of the hole 204 is also disposed at a location beyond the center line in the direction of the length of the base plate (i.e. line B-B′ in FIG. 3 ) according to the design of the location of a picture projected from a general projector. Furthermore, open type rectangular notches 2022 and 2032 are respectively disposed at the centers of the lower edge of the upper adjusting plate 202 and the upper edge of the lower adjustable plate 203 , the sizes of these two open type rectangular notches 2022 and 2032 are same and corresponding to each other. And, sleeves 2021 and 2031 are respectively disposed at both of the left and the right sides of the rectangular notches 2022 and 2032 of the upper and the lower adjustable plates 202 and 203 . The sizes of the center holes of the sleeves 2011 , 2021 and 2031 respectively disposed at the left and the right sides of the base plate 201 and the upper and the lower adjustable plates are same; the center lines of the center holes at the left and the light sides are respectively aligned into one line and the two lines are parallel after assembly as FIG. 4 shows. In addition, screws exist in the center holes of only one pair of the sleeve 2021 at the right side of the upper adjustable plate 202 and the sleeve 2031 at the left side of the lower adjustable plate 203 , and the sleeve 2021 at the left side of the upper adjustable plate 202 and the sleeve 2031 at the fight side of the lower adjustable plate 203 and can be extended out of them to screw thread portions 2023 and 2033 to strengthen the moving stability when the upper and the lower adjustable plates driven by a bolt 205 . For convenience in explanation, the former structure is adopted in FIGS. 3 and 4 , i.e. the screw threads are only disposed in the center holes of the sleeve 2021 at the right side of the upper adjustable plate 202 and the sleeve 2031 at the left side of the lower adjustable plate 203 . And, no screw thread exists in the center holes of all the sleeves on the base plate 201 .
[0023] Please refer to FIG. 4 . When the base 201 and the upper and the lower adjustable plate 202 and 203 want to be assembled to a lens filtering mask, the upper and the lower adjustable plates 202 and 203 are first placed between the upper and the lower sleeves 2011 on the base plate 201 . Next, two bolts 205 are respectively inserted into the sleeves 2011 , 2021 , 2031 and 2011 disposed into one straight line at the two sides of the base plate and the upper and the lower adjustable plates 202 and 203 . Fixing washers 207 are then engaged with end parts 2052 of the bolts 205 to prevent the assembling elements from falling down after the bolts 205 are passed through the lowermost end of the sleeve 2011 for conforming to a different aspect of projection picture, only rotate a rotating button on the bolt 205 , and the left sleeve 2021 on the upper adjustable plate 202 engaged with the bolt 205 or/and right sleeve 2031 on the lower adjustable 203 can then be driven to move the upper or/and lower adjustable plate/plates upwards or downward to change the size of a close rectangular hole formed by the open type rectangular notches 2022 and 2032 . Generally speaking, the ratio of the length and the width of the adjusted close rectangular hole can be an aspect ratio of a general projection picture such as 4:3, 16:9, 2.35:1 or anything else.
[0024] Please refer to FIG. 5 . FIG. 5 is a schematic view showing a lens shielding mask is mounted on a projector according to the present invention. When the lens shielding mask 20 wants to be mounted on the projector 1 , holding sheets on the base plate 201 are respectively clamped at the upper and the lower rims of the projector close to the projection lens 2 and the ratio of the length and the width of the close rectangular hole is adjusted according to the steps mentioned above to conform to the aspect ratio of a projection picture.
[0025] Please refer to FIGS. 6 and 7 . FIGS. 6 and 7 are explosive and cross sectional views respectively showing parts and after-assembly structure of a lens shielding mask with an adjustable optical grating of still another preferred embodiment according to the present invention. A lens shielding mask 30 with an adjustable optical grating comprises a base plate 301 and upper and lower adjustable plates 302 and 303 . A sleeve 3011 is disposed on every corner of the base plate 301 ; no screw thread is existed in any one of these four sleeves. A rectangular hole 304 is further opened in the base plate 301 ; the disposition location is identical to the rectangular hole 204 in the last preferred embodiment mentioned above so that the detail thereof is omitted here. Furthermore, in the base plate 301 , two guide notches 307 are disposed at the lateral center line of the rectangular hole 304 and adjacent to the two flank sides of the base plate. Two open type rectangular notches 3022 and 3032 , which are corresponding to each other and have a same size, are respectively disposed in the middles of the lower end of the upper adjustable plate 302 and the upper end of the lower adjustable plate 303 ; the width of the open type rectangular notches are almost equal to the one of the rectangular hole in the base plate. And, a lever plate connecting seat 308 is respectively disposed at each one of the two sides of the open type rectangular notches of the upper and the lower adjustable plates 302 and 303 ; an accepting hole 3081 is opened in each connecting seat 308 . Both of sleeves 3021 and 3031 are respectively disposed at the left and the right sides of the upper and the lower adjustable plates 302 and 303 . The sizes of the center holes of the sleeves at the same sides are equal, and screw threads are disposed in the center holes of the sleeves at the same side; the threads are disposed in the center holes of the sleeves at the left sides of the plates according to the present invention only for explaining the detail easily.
[0026] The assembling of the lens filtering mask 30 according to the present invention can be seen in FIG. 7 . First, a buckling pin 3091 disposed on a lever plate shown in FIG. 6 is buckled into the accepting hole 3092 disposed in a corresponding and the end of the buckling pin 3091 is engaged into the guide notch 307 , and then another buckling pin 3091 on each lever plate is engaged into the accepting hole 3081 in the each connecting seat 308 on the upper and the lower adjustable plate 302 and 303 . Each connecting point after being connected including the one between the lever plates 309 and the one between the lever plate 309 and connecting seat 308 is pivotally connected. Thereafter, the whole set of after-combination upper and lower adjustable plates 302 and 303 and the lever plate 309 are mounted between the upper and the lower sleeves 3011 on the base plate 301 . After the center holes of the sleeves 3011 , 3021 , 3031 and 3011 on the left and right sides of the base plate 30 and the upper and the lower adjustable plates 302 and 303 are aligned, a bolt with both of left and right screw threads respectively disposed on the upper and the lower parts thereof and a straight shaft shown in FIG. 6 are respectively inserted into the left and the right sides of sleeve arrays. Fixing washers are used to engage respectively with both ends of the bolt 305 and the straight shaft 306 to prevent all the assembling elements from dropping after the bolt 305 and the straight shaft 306 are passed through the lowermost end of the sleeve 3011 the upper and the lower adjustable plates 302 and 303 can be closed and opened synchronically to adjust the size of the close opening formed by the open type rectangular notches 3022 and 3032 to conform to the size of the projection picture after the bolt with left and right screw threads respectively disposed on the upper and the lower parts thereof is engaged with the sleeves 3021 and 3031 in which the threads in the center holes of them are reverse to each other respectively disposed on the left sides of the upper and the lower adjustable plates. The coordination of the lever plates 309 and guide notches 307 and the coordination of the straight shaft 306 and the sleeves on the right side are operated to guide the upper and the lower adjustable plates 302 and 303 to move up and down smoothly.
[0027] Furthermore, the thread of the center holes of the sleeves at the left side can also be extended to the outsides of the sleeves to increase the driven stability of the upper and the lower adjustable plates, it is the same situation as described in the preferred embodiment of the present invention mentioned above.
[0028] Besides, the holding element used in the preferred embodiment mentioned above can also be used in this preferred embodiment for mounting convenience. The detail for mounting the mask on a projector is also omitted here because it is not different from the situation mentioned in the last preferred embodiment.
[0029] It is noted that the outer suspension type lens shielding mask for a projection apparatus described above is the preferred embodiments of the present invention for the purpose of illustration only, and are not intended as a definition of the limits and scope of the invention disclosed. Any modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of the present invention. | An outer suspension type lens shielding mask for a projection apparatus including a sheet body and holding element, in which a rectangular hole is opened in the sheet body, and the sheet body is combined with the holding element to be fixed on a projection apparatus Another outer suspension type lens shielding mask includes a base plate, in which a rectangular hole is opened in the middle part thereof, and upper and lower adjustable plates are installed behind the base plate An open rectangular notch is respectively disposed at the middle parts of the upper and the lower adjustable plates. An adjustment mechanism includes a plurality of connecting elements connected to the base plate and the upper and the lower adjustable plates for adjusting the relative positions thereof, to avoid bad shadows yielded outside of a picture due to light diffraction and improve the quality of visual amusement. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of Korean Patent Application No. 10-2011-0125307, filed on Nov. 28, 2011, entitled “Fuel Cell Module”, which is hereby incorporated by reference in its entirety into this application.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to a fuel cell module.
[0004] 2. Description of the Related Art
[0005] The fuel cell is an apparatus that directly converts chemical energy of fuel (hydrogen, LNG, LPG, or the like) and air (oxygen) into electricity and heat by an electrochemical reaction. The power generation technologies according to the prior art need to perform processes such as fuel combustion, vapor generation, turbine driving, generator driving, or the like. On the other hand, the fuel cell is a new conceptual power generation technology that does not induce environmental problems while increasing efficiency. The fuel cell little emits air pollutants such as SOx, NOx, or the like, can achieve pollution-free power generation due to the reduced generation of carbon dioxide, and can achieve low noise, non-vibration, or the like.
[0006] As the fuel cell, there are various types of fuel cells such as a phosphoric acid fuel cell (PAFC), an alkaline fuel cell (AFC), a polymer electrolyte type fuel cell (PEMFC), a direct methanol fuel cell, a solid oxide fuel cell (SOFC), or the like. Among others, the solid oxide fuel cell (SOFC) can implement high-efficiency generation, can implement, complex generation such as coal gas-fuel cell-gas turbine, or the like, and has various generation capacity and as a result, is appropriate for a small generator, a large generator, or a distributed power supply. Therefore, the solid oxide fuel cell is an essential generation technology for entering hydrogen economy society in future.
[0007] The prior art collects current by forming metal lines on the outside of a collector collecting current generated from the fuel cell (Korean Patent Laid-Open Publication No. 2011-0085848). However, in this structure, as a size of a cell is increased, the number of expensive metal lines is increased, which leads to increase manufacturing costs and make a structure complicated. As a result, it is difficult to mass-produce the solid oxide fuel cell.
SUMMARY OF THE INVENTION
[0008] The present invention has been made in an effort to provide a fuel cell module having a fuel cell easily inserted thereinto.
[0009] Further, the present invention has been made in an effort to provide a fuel cell module capable of improving current collector capacity by maximizing a contact area with a fuel cell.
[0010] In addition, the present invention has been made in an effort to provide a fuel cell module capable of improving durability by facilitating oxidation-resistance coating.
[0011] According to a preferred embodiment of the present invention, there is provided a fuel cell module, including: a first support part including a first body part surrounding one side of an outer peripheral surface of a fuel cell and a first connection part formed on one side of the first body part in a longitudinal direction; a second support part including a second body part surrounding the other side of the outer peripheral surface of the fuel cell and the second connection part formed on one side of the second body part in a longitudinal direction; and a fixing part passing through the first connection part and the second connection part to connect and fix the first connection part and the second connection part to each other.
[0012] The first body part may include: a first inner surface contacting and surrounding an outer peripheral surface of the fuel cell and including a first air supplying hole through which air passes; and a first outer surface spaced apart from the first inner surface at a predetermined distance so as to surround the first inner surface and connected with both sides of the first inner surface in a longitudinal direction, wherein a first air passage that is a space formed by being spaced apart from the first outer surface is connected with the first air supplying hole.
[0013] The first outer surface may be formed to have rigidity stronger than that of the first inner surface.
[0014] The thickness of the first outer surface may be formed to be thicker than that of the first inner surface.
[0015] The first inner surface and the first outer surface may be made of an alloy of stainless steel.
[0016] The second body part may include: a second inner surface contacting and surrounding an outer peripheral surface of the fuel cell and including a second air supplying hole through which air passes; and a second outer surface spaced apart from the second inner surface at a predetermined distance so as to surround the second inner surface and connected with both sides of the second inner surface in a longitudinal direction, wherein a second air passage that is a space formed by being spaced apart from the second outer surface at a predetermined distance is connected with the second air supplying hole.
[0017] The second outer surface may be formed to have rigidity stronger than that of the second inner surface.
[0018] The thickness of the second outer surface may be formed to be thicker than that of the second inner surface.
[0019] The second inner surface and the second outer surface may be made of an alloy of stainless steel.
[0020] The first connection part may be protruded from one side of the first body part and provided with a plurality of first through holes formed in one side of the first body part in a longitudinal direction and having a form penetrating through a center thereof in the longitudinal direction.
[0021] The second connection part may be protruded from one side of the second body part and provided with a plurality of second through holes formed in one side of the second body part in a longitudinal direction and having a form penetrating through a center thereof in the longitudinal direction.
[0022] According to another preferred embodiment of the present invention, there is provided a fuel cell module, including: an inner surface contacting and surrounding an outer peripheral surface of a fuel cell and including an air supplying hole through which air passes; a first outer surface surrounding a part of the inner surface while being spaced apart from the inner surface at a predetermined distance and having one side thereof connected with one side of the inner surface in a longitudinal direction; a second outer surface surrounding a part of the inner surface while being spaced apart from the inner surface at a predetermined distance and having the other side thereof connected with the other side of the inner surface in a longitudinal direction; and a fixing part inserted into the other side of the first outer surface and one side of the second outer surface.
[0023] The first outer surface and the second outer surface may be formed to have rigidity stronger than the inner surface.
[0024] The thickness of the first outer surface and the second outer surface may be formed to be thicker than that of the inner surface.
[0025] The first outer surface, the second outer surface, the inner surface, and the outer surface may be made of an alloy of stainless steel.
[0026] The other side of the first outer surface and one side of the second outer surface may be provided with a plurality of insertion holes formed in a longitudinal direction.
[0027] One surface of the fixing part may be provided with a first control bar protruded corresponding to the insertion holes of the first outer surface and the second outer surface and inserted into the insertion holes.
[0028] One surface of the fixing part may be provided with a second control bar protruded corresponding to the insertion holes of the first outer surface and the second outer surface and inserted into the insertion holes and formed so as to be spaced apart from the first control bar to the outside at a predetermined distance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is an exemplified diagram showing a fuel cell module according to a preferred embodiment of the present invention in which a fuel cell is mounted.
[0030] FIG. 2 is an exemplified diagram showing a fuel cell module according to the preferred embodiment of the present invention.
[0031] FIG. 3 is an exemplified diagram showing a multilayered fuel cell module according to the preferred embodiment of the present invention.
[0032] FIG. 4 is an exemplified diagram showing a fuel cell module according to another preferred embodiment of the present invention in which a fuel cell is mounted.
[0033] FIG. 5 is an exemplified diagram showing a fuel cell module according to another preferred embodiment of the present invention.
[0034] FIG. 6 is an exemplified diagram showing a fuel cell module according to another preferred embodiment of the present invention.
[0035] FIG. 7 is an exemplified diagram showing a multilayered fuel cell module according to another preferred embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0036] Various features and advantages of the present invention will be more obvious from the following description with reference to the accompanying drawings.
[0037] The terms and words used in the present specification and claims should not be interpreted as being limited to typical meanings or dictionary definitions, but should be interpreted as having meanings and concepts relevant to the technical scope of the present invention based on the rule according to which an inventor can appropriately define the concept of the term to describe most appropriately the best method he or she knows for carrying out the invention.
[0038] The above and other objects, features and advantages of the present invention will be more clearly understood from preferred embodiments and the following detailed description taken in conjunction with the accompanying drawings. In the specification, in adding reference numerals to components throughout the drawings, it is to be noted that like reference numerals designate like components even though components are shown in different drawings.
[0039] Further, when it is determined that the detailed description of the known art related to the present invention may obscure the gist of the present invention, the detailed description thereof will be omitted. In the description, the terms “first”, “second”, and so on are used to distinguish one element from another element, and the elements are not defined by the above terms.
[0040] Hereinafter, a fuel cell module according to preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0041] FIG. 1 is an exemplified diagram showing a fuel cell module according to a preferred embodiment of the present invention in which a fuel cell is mounted.
[0042] A fuel cell module 100 is an apparatus that collects electric energy generated during a generation process of a fuel cell 200 . Referring to FIG. 1 , the fuel cell module 100 may include a first support part 110 , a second support part 120 , and a fixing part 130 .
[0043] The first support part 110 may include a first body part 111 surrounding one side of an outer peripheral surface of the fuel cell 200 and a first connection part (not shown) formed on one side of the first body part 111 in a longitudinal direction.
[0044] The first body part 111 may include a first inner surface 112 , a first outer surface 114 , and a first air passage 115 .
[0045] The first inner surface 112 is formed to surround the fuel cell 200 by directly contacting the outer peripheral surface of the fuel cell 200 . The first inner surface 112 may be formed in a curved surface so as to correspond to the outer peripheral surface of the fuel cell 200 . Further, the first inner surface 112 may be made of flexible metals. For example, the first inner surface 112 may be made of an alloy of thin stainless steel. That is, the first inner surface 112 may be made of stainless steel but may be thinly formed to have flexible properties. As such, the first inner surface 112 is a curved surface corresponding to the fuel cell 200 and may be made of flexible metals, such that the contact area of the fuel cell 200 is expanded as maximally as possible, thereby maximizing the current collector efficiency.
[0046] The first outer surface 114 may be formed to surround the first inner surface 112 while being spaced apart from the first inner surface 112 at a predetermined distance. Both sides of the first outer surface 114 in a longitudinal direction may each be connected to both sides of the first inner surface 112 in a longitudinal direction. The first outer surface 114 may be made of rigid metals. For example, the first outer surface 114 may be made of an alloy of thick stainless steel. That is, the first outer surface 114 may be made of stainless steel but, may be thickly formed to have rigid properties. As such, the first outer surface 114 may be made of rigid metals to support the first inner surface 112 on which the fuel cell 200 is mounted.
[0047] The first air passage 115 is a space formed by spacing the first inner surface 112 and the first outer surface 114 from each other at a predetermined distance. Air to be supplied to the fuel cell 200 passes through the first air passage 115 .
[0048] The first connection part (not shown) may be formed on one side of the first body part 111 in a longitudinal direction. That is, the first connection part (not shown) may be formed to be protruded to one of both sides on which the first inner surface 112 is connected with the first outer surface 114 . The first connection part (not shown) is to fasten the first support part 110 and the second support part 120 to each other and the fixing part 130 may be inserted therebetween. In FIG. 1 , the first connection part (not shown) is not shown according to the overlapping with a second connection part 126 of the second support part 120 .
[0049] The second support part 120 may include a second body part 121 surrounding the other side of an outer peripheral surface of the fuel cell 200 and a second connection part 126 formed on one side of the second body part 121 in a longitudinal direction.
[0050] The second body part 121 may include a second inner surface 122 , a second outer surface 124 , and a second air passage 125 .
[0051] The second inner surface 122 is formed to surround the fuel cell 200 by directly contacting the outer peripheral surface of the fuel cell 200 . The second inner surface 122 may be formed in a curved surface so as to correspond to the outer peripheral surface of the fuel cell 200 . Further, the second inner surface 122 may be made of flexible metals. For example, the second inner surface 122 may be made of an alloy of thin stainless steel. As such, the second inner surface 122 is a curved surface corresponding to the fuel cell 200 and may be made of flexible metals, such that the contact area of the fuel cell 200 is expanded as maximally as possible, thereby maximizing the current collector efficiency.
[0052] The second outer surface 124 may be formed to surround the second inner surface 122 while being spaced apart from the second inner surface 122 at a predetermined distance. Both sides of the second outer surface 124 in a longitudinal direction may each be connected to both sides of the second inner surface 122 in a longitudinal direction. The second outer surface 124 may be made of rigid metals. For example, the second outer surface 124 may be made of thick stainless steel. As such, the second outer surface 124 may be made of rigid metals to support the second inner surface 122 on which the fuel cell 200 is mounted.
[0053] The second air passage 125 is a space formed by spacing the second inner surface 122 and the second outer surface 124 from each other at a predetermined distance. Air to be supplied to the fuel cell 200 passes through the second air passage 125 .
[0054] The second connection part 126 may be formed on one side of the second body part 121 in a longitudinal direction. That is, the second connection part 126 may be formed to be protruded to one of both sides on which the second inner surface 122 is connected with the second outer surface 124 . The second connection part 126 , which fastens the first support part 110 and the second support part 120 to each other, may be inserted with the fixing part 130 .
[0055] The fixing part 130 is a member for fastening the first support part 110 and the second support part 120 to each other. The fixing part 130 may be inserted into the connection part in the state in which the first connection part (not shown) of the first support part 110 and the second connection part 126 of the second support part 120 are connected with each other. As such, the fixing part 130 is inserted in the state in which the first support part 110 is connected with the second support part 120 , such that the first support part 110 and the second support part 130 may be fixed in the state in which the fuel cell 200 is mounted.
[0056] The aforementioned fuel cell module 100 may be formed in a form in which the first support part 110 , the second support part 120 , and the fixing part 130 surround the fuel cell 200 .
[0057] FIG. 2 is an exemplified diagram showing the fuel cell module according to the preferred embodiment of the present invention.
[0058] Referring to FIG. 2 , the fuel cell module 100 may include the first support part 110 , the second support part 120 , and the fixing part 130 .
[0059] The first support part 110 may include the first body part 111 and a first connection part 116 .
[0060] The first body part 111 may include a first inner surface 112 , a first outer surface 114 , a first air passage 115 , and a first air supplying hole 113 .
[0061] The first inner surface 112 is formed to surround the fuel cell (not shown) by directly contacting the outer peripheral surface of the fuel cell (not shown). The first inner surface 112 may be formed in a curved surface so as to correspond to the outer peripheral surface of the fuel cell (not shown). Further, the first inner surface 112 may be made of flexible metals. For example, the first inner surface 112 may be made of thin stainless steel. That is, the first inner surface 112 may be made of stainless steel but may be thinly formed to have flexible properties. As such, the first inner surface 112 is a curved surface corresponding to the fuel cell (not shown) and may be made of flexible metals, such that the contact area of the fuel cell (not shown) is expanded as maximally as possible, thereby maximizing the current collector efficiency. In addition, the first inner surface 112 may be formed with the first air supplying hole 113 for supplying air to the fuel cell (not shown).
[0062] The first outer surface 114 may be formed to surround the first inner surface 112 while being spaced apart from the first inner surface 112 at a predetermined distance. Both sides of the first outer surface 114 in a longitudinal direction may each be connected to both sides of the first inner surface 112 in a longitudinal direction. The first outer surface 114 may be made of rigid metals. For example, the first outer surface 114 may be made of thick stainless steel. That is, the first outer surface 114 may be made of stainless steel but may be thickly formed to have rigid properties. As such, the first outer surface 114 may be made of rigid metals to support the first inner surface 112 on which the fuel cell (not shown) is mounted.
[0063] The first air passage 115 is a space formed by spacing the first inner surface 112 and the first outer surface 114 from each other at a predetermined distance. The first air passage 115 may be connected with the first air supplying hole 113 of the first inner surface 112 .
[0064] The plurality of first air supplying holes 113 may be formed on the first inner surface 112 . The first air passage 115 may be connected to the inside of the fuel cell module 100 , in which the fuel cell (not shown) is mounted, by the first air supplying hole 113 . That is, the air passing through the first air passage 115 may be supplied to the fuel cell (not shown) mounted in the fuel cell module 110 by the first air supplying hole 113 .
[0065] The first connection part 116 may be formed on one side of the first body part 111 in a longitudinal direction. That is, the first connection part 116 may be formed to be protruded to one of both sides on which the first inner surface 112 is connected with the first outer surface 114 . The first connection part 116 is to fasten the first support part 110 and the second support part 120 to each other. The first connection part 116 may include a first through hole 117 into which the fixing part 130 for fastening the first support part 110 and the second support part 120 to each other is inserted.
[0066] The first through hole 117 may be formed at the center of the first connection part 116 so as to longitudinally penetrate therethrough.
[0067] The second support part 120 may include the second body part 121 surrounding the other side of the outer peripheral surface of the fuel cell (not shown) and the second connection part 126 formed on one side of the second body part 121 in the longitudinal direction.
[0068] The second body part 121 may include the second inner surface 122 , the second outer surface 124 , and the second air passage 125 .
[0069] The second inner surface 122 is formed to surround the fuel cell (not shown) by directly contacting the outer peripheral surface of the fuel cell (not shown). The second inner surface 122 may be formed in a curved surface so as to correspond to the outer peripheral surface of the fuel cell (not shown). Further, the second inner surface 122 may be made of flexible metals. For example, the second inner surface 122 may be made of thin stainless steel. That is, the second inner surface 122 is made of stainless steel but may be thinly formed to have flexible properties. As such, the second inner surface 122 is a curved surface corresponding to the fuel cell (not shown) and is made of flexible metals, such that the contact area of the fuel cell (not shown) is expanded as maximally as possible, thereby maximizing the current collector efficiency. In addition, the second inner surface 122 may be formed with the second air supplying hole 123 for supplying air to the fuel cell (not shown).
[0070] The second outer surface 124 may be formed to surround the second inner surface 122 while being spaced apart from the second inner surface 122 at a predetermined distance. Both sides of the second outer surface 124 in a longitudinal direction may each be connected to both sides of the second inner surface 122 in a longitudinal direction. The second outer surface 124 may be made of rigid metals. For example, the second outer surface 124 may be formed of thick stainless steel. That is, the second outer surface 124 is made of stainless steel but may be thickly formed to have rigid properties. As such, the second outer surface 124 may be made of rigid metals to support the second inner surface 122 on which the fuel cell (not shown) is mounted.
[0071] The second air passage 125 is a space formed by spacing the second inner surface 122 and the second outer surface 124 from each other at a predetermined distance. The second air passage 125 may be connected with the second air supplying hole 123 of the second inner surface 122 .
[0072] The plurality of second air supplying holes 123 may be formed on the first inner surface 122 . The second air passage 125 may be connected to the inside of the fuel cell module 100 , in which the fuel cell (not shown) is mounted, by the second air supplying hole 123 . That is, the air passing through the second air passage 125 may be supplied to the fuel cell (not shown) mounted in the fuel cell module 110 by the second air supplying hole 123 .
[0073] The second connection part 126 may be formed on one side of the second body part 121 in a longitudinal direction. That is, the second connection part 126 may be formed to be protruded to one of both sides on which the second inner surface 122 is connected with the second outer surface 124 . The second connection part 126 is to fasten the first support part 110 and the second support part 120 to each other. The second connection part 126 may include a second through hole 127 into which the fixing part 130 for fastening the first support part 110 and the second support part 120 to each other is inserted.
[0074] The second through hole 127 may be formed at the center of the second connection part 126 so as to longitudinally penetrate therethrough.
[0075] The fixing part 130 is a member for fastening the first support part 110 and the second support part 120 to each other. The fixing part 130 may be inserted in the state in which the first connection part 116 of the first support part 110 and the second connection part 126 of the second support part 120 are connected with each other. That is, as the first connection part 116 and the second connection part 126 are connected with each other, the first through hole 117 of the first connection part 116 and the second through hole 127 of the second connection part 126 may overlap with each other. The first support part 110 and the second support part 120 may be fastened with each other by inserting the fixing part 130 into the first through hole 117 and the second through hole 127 .
[0076] FIG. 3 is an exemplified diagram showing a multilayered fuel cell module according to the preferred embodiment of the present invention.
[0077] Referring to FIG. 3 , a multilayered fuel cell module may be formed by alternately stacking at least two fuel cell modules 100 and 100 - 1 in which the fuel cells 200 and 210 are mounted. When the fuel cell modules 100 and 100 - 1 in which the fuel cells 200 and 210 are mounted are alternately stacked, the inner surfaces of the fuel cell modules 100 and 100 - 1 selectively contact the outer peripheral surfaces of the fuel cells 200 and 210 and the outer peripheral surfaces of the fuel cell modules 100 and 100 - 1 may contact connection members 140 and 180 and a positive current collector plate 194 .
[0078] Describing an example as shown in FIG. 3 , the first fuel cell module 100 , the second fuel cell module 100 - 1 , the first fuel cell 200 , the second fuel cell 210 , the first connection member 140 , the second connection member 180 , the positive current collector plate 194 , and a negative current collector plate 191 , and an insulating plate 193 are stacked.
[0079] The first fuel cell module 100 is mounted with the first fuel cell 200 . The lower portion of the outer peripheral surface of the first fuel cell module 100 may contact the positive current collector plate 194 . Further, the inner surface of the first fuel cell module 100 may contact one side of the first fuel cell 200 . Here, one side of the first fuel cell 200 may be a bottom surface.
[0080] The first fuel cell 200 is mounted in the first fuel cell module 100 . The bottom surface of the first fuel cell 200 may contact the first fuel cell module 100 . Further, a top surface of the first fuel cell 200 may contact the first connection member 140 .
[0081] The first connection member 140 is a member for transferring the negative current generated from the first fuel cell 200 to the outside of the first fuel cell 200 . The first connection member 140 , which is a member for current collection of the first fuel cell 200 , may be made of metals having electric conductivity. One side of the first connection member 140 is connected with the first fuel cell 200 . That is, one side of the first connection member 140 may be formed so as to be electrically connected to an anode support (not shown) in the first fuel cell 200 . In addition, the other side of the first connection member 140 may contact the lower portion of the outer peripheral surface of the second fuel cell module 100 - 1 .
[0082] The second fuel cell module 100 is mounted with the second fuel cell 210 . The lower portion of the outer peripheral surface of the second fuel cell module 100 - 1 may contact the first connection member 140 . The second fuel cell module 100 - 1 may be electrically connected with the first fuel cell 200 by contacting the first connection member 140 . The inner surface of the second fuel cell module 100 - 1 may contact one side of the second fuel cell 210 . Here, one side of the second fuel cell 210 may be a bottom surface.
[0083] The second fuel cell 210 is mounted in the second fuel cell module 100 - 1 . The bottom surface of the second fuel cell 210 may contact the second fuel cell module 100 - 1 . Further, the top surface of the second fuel cell 210 may contact the second connection member 180 .
[0084] The second connection member 180 is a member for transferring the negative current generated from the second fuel cell 210 to the outside of the second fuel cell 210 . The second connection member 180 , which is a member for current collection of the second fuel cell 210 , may be made of metals having electric conductivity. One side of the second connection member 180 is connected with the second fuel cell 210 . That is, one side of the second connection member 180 may be formed so as to be electrically connected to an anode support (not shown) in the second fuel cell 210 . In addition, the lower side of the second connection member 180 may contact the negative current collector plate 191 .
[0085] The positive current collector plate 194 may collect positive current generated by the first fuel cell 200 and the second fuel cell 210 .
[0086] The negative current collector plate 191 may collect negative current generated by the first fuel cell 200 and the second fuel cell 210 .
[0087] The insulating plate 193 may be formed on both sides of the first fuel cell module 100 and the second fuel cell module 100 - 1 . The insulating plate 193 is pressed to both sides of the first fuel cell module 100 , such that the mounted first fuel cell 200 may better contact the first fuel cell module 100 . In addition, the insulating plate 193 is pressed to both sides of the second fuel cell module 100 - 1 , such that the mounted second fuel cell 210 may better contact the second fuel cell module 100 - 1 .
[0088] As such, the first fuel cell 200 and the second fuel cell 210 may be disposed vertically by the first fuel cell module 100 and the second fuel cell module 100 - 1 . Further, the first fuel cell module 100 and the second fuel cell module 100 - 1 may collect the positive current generated from the first fuel cell 200 and the second fuel cell 210 to the positive current collector plate 194 by serially connecting the first fuel cell 200 and the second fuel cell 210 that are vertically disposed.
[0089] The preferred embodiment of the present invention describes two fuel cell modules and two fuel cells, but is only an example. Therefore, the number of fuel cell modules and fuel cells is not limited thereto. The number of fuel cell modules and fuel cells may be changed by those skilled in the art.
[0090] In addition, the preferred embodiment of the present invention describes the case in which the plurality of fuel cells is connected to one another in series by vertically disposing the plurality of fuel cell modules but is only the example. The plurality of fuel cells may be connected to one another in parallel by horizontally disposing the plurality of fuel cell modules. In addition, the plurality of fuel cells may simultaneously be connected to one another in series and in parallel by vertically and horizontally connecting the plurality of fuel cell modules to one another.
[0091] In the preferred embodiment of the present invention, a first inner surface and a second inner surface may be made of flexible metals and the first outer surface and the second outer surface may be made of rigid metals, which may be expressed in relative terms. That is, a meaning that metals forming the first inner surface and the second inner surface are flexible is more flexible than metals forming the first outer surface and the second outer surface. Further, a meaning that metals forming the first outer surface and the second outer surface are rigid is more flexible than metals forming the first inner surface and the second inner surface. Here, according to the preferred embodiment of the present invention, flexibility and rigidity may be determined at a thickness of an alloy of stainless steel in that the first inner surface, the second inner surface, the first outer surface, and the second outer surface may be made of an alloy of the same stainless steel.
[0092] FIG. 4 is an exemplified diagram showing a fuel cell module according to another preferred embodiment of the present invention in which a fuel cell is mounted.
[0093] Referring to FIG. 4 , a fuel cell module 300 may include an inner surface 310 , a first outer surface 331 , a second outer surface 332 , an air passage 340 , a first connection part 351 , a second connection part 353 , and a fixing part 360 .
[0094] The inner surface 310 is formed to surround a fuel cell 400 by directly contacting the outer peripheral surface of the fuel cell 400 . For example, the inner surface 310 may be formed to surround both sides and the lower portion of the fuel cell 400 . The inner surface 310 may be formed in a curved surface so as to correspond to the outer peripheral surface of the fuel cell 400 . Further, the inner surface 310 may be made of flexible metals. For example, the inner surface 310 may be made of thin stainless steel. That is, the inner surface 310 is made of stainless steel but may be thinly formed to have flexible properties. As such, the inner surface 310 is a curved surface corresponding to the fuel cell 400 and is made of flexible metals, such that the contact area of the fuel cell 400 is expanded as maximally as possible, thereby maximizing the current collector efficiency.
[0095] The first outer surface 331 may be formed to surround a portion of the inner surface 310 while being spaced apart from the first inner surface 310 at a predetermined distance. One side of the first outer surface 331 in a longitudinal direction may be connected to one side of the inner surface 310 in a longitudinal direction. The first outer surface 331 may be made of rigid metals. For example, the first outer surface 331 may be made of thick stainless steel. That is, the first outer surface 331 is made of stainless steel but may be thickly formed to have rigid properties. As such, the first outer surface 331 may be made of rigid metals to support the inner surface 310 on which the fuel cell 400 is mounted.
[0096] The second outer surface 332 may be formed to surround a portion of the inner surface 310 while being spaced apart from the first inner surface 310 at a predetermined distance. The other side of the second outer surface 332 in a longitudinal direction may be connected to the other side in a longitudinal direction of the inner surface 310 . The second outer surface 332 may be made of rigid metals. For example, the second outer surface 332 may be made of thick stainless steel. That is, the second outer surface 332 is made of stainless steel but may be thickly formed to have rigid properties. As such, the second outer surface 332 may be made of rigid metals to support the inner surface 310 on which the fuel cell 400 is mounted.
[0097] The first connection part 351 may be longitudinally formed to the other side of the first outer surface 331 . The first connection part 351 may be inserted with a control bar 361 of the fixing part 360 .
[0098] The second connection part 353 may be longitudinally formed to the other side of the second outer surface 332 . The second connection part 353 may be inserted with the control bar 361 of the fixing part 360 .
[0099] The fixing part 360 is a member for fixing the first outer surface 331 and the second outer surface 332 so that the fuel cell 400 is mounted in the inner surface 310 . The fixing part 360 may include the control bar 361 . The control bar 361 may be a plurality of insertion parts protruded from one surface of the fixing part 360 . The control bar 361 may be inserted in a form in which the first control bar 361 penetrates through the first connection part 351 and the second connection part 353 . That is, the fixing part 360 fixes the first outer surface 331 and the second outer surface 332 by inserting the control bar 361 into the first connection part 351 and the second connection part 353 , such that the inner surface 310 may be fixed at a predetermined width.
[0100] The air passage 340 is a space formed by the inner surface 310 , the first outer surface 331 spaced apart from the inner surface 310 at a predetermined distance, and the second outer surface 332 . The air to be supplied to the fuel cell 400 mounted in the fuel cell module 300 may pass through the air passage 340 .
[0101] As described above, the fuel cell module 300 may be formed in a form in which the inner surface 310 , the first outer surface 331 , the second outer surface 332 , and the fixing part 360 surround the fuel cell 400 .
[0102] FIG. 5 is an exemplified diagram showing a fuel cell module according to another preferred embodiment of the present invention.
[0103] Referring to FIG. 5 , the fuel cell module 300 may include the inner surface 310 , the air supplying hole 320 , the first outer surface 331 , the second outer surface 332 , the air passage 340 , the first connection part 351 , the second connection part 353 , and the fixing part 360 .
[0104] The inner surface 310 is formed to surround the fuel cell (not shown) by directly contacting the outer peripheral surface of the fuel cell (not shown). For example, the inner surface 310 may be formed to surround both sides and the lower portion of the fuel cell (not shown). The inner surface 310 may be formed in a curved surface so as to correspond to the outer peripheral surface of the fuel cell (not shown). Further, the inner surface 310 may be made of flexible metals. For example, the inner surface 310 may be made of thin stainless steel. That is, the inner surface 310 is made of stainless steel but may be thinly formed to have flexible properties. As such, the inner surface 310 is a curved surface corresponding to the fuel cell (not shown) and is made of flexible metals, such that the contact area of the fuel cell (not shown) is expanded as maximally as possible, thereby maximizing the current collector efficiency. In addition, the inner surface 310 may be formed with the air supplying hole 320 for supplying air to the fuel cell (not shown).
[0105] The first outer surface 331 may be formed to surround a portion of the inner surface 310 while being spaced apart from the first inner surface 310 at a predetermined distance. One side of the first outer surface 331 in a longitudinal direction may be connected to one side of the inner surface 310 in a longitudinal direction. The first outer surface 331 may be made of rigid metals. For example, the first outer surface 331 may be made of thick stainless steel. That is, the first outer surface 331 is made of stainless steel but may be thickly formed to have rigid properties. As such, the first outer surface 331 may be made of rigid metals to support the inner surface 310 on which the fuel cell (not shown) is mounted.
[0106] The second outer surface 332 may be formed to surround a portion of the inner surface 310 while being spaced apart from the first inner surface 310 at a predetermined distance. The other side of the second outer surface 332 in a longitudinal direction may be connected to the other side in a longitudinal direction of the inner surface 310 . The second outer surface 332 may be made of rigid metals. For example, the second outer surface 332 may be made of thick stainless steel. That is, the second outer surface 332 is made of stainless steel but may be thickly formed to have rigid properties. As such, the second outer surface 332 may be made of rigid metals to support the inner surface 310 on which the fuel cell (not shown) is mounted.
[0107] The air passage 340 is a space formed by the inner surface 310 , the first outer surface 331 spaced apart from the inner surface 310 at a predetermined distance, and the second outer surface 332 . The air to be supplied to the fuel cell (not shown) mounted in the fuel cell module 300 may pass through the air passage 340 .
[0108] The plurality of air supplying holes 320 may be formed in the inner surface 310 . The air passage 340 may be connected to the inside of the fuel cell module (not shown), in which the fuel cell (not shown) is mounted, by the air supplying hole 320 . That is, the air passing through the air passage 340 may be supplied to the fuel cell (not shown) mounted in the fuel cell module 110 by the air supplying hole 320 .
[0109] The first connection part 351 may be longitudinally formed to the other side of the first outer surface 331 . The first connection part 351 may be inserted with the first through hole 352 into which the control bar 361 of the fixing part 360 is inserted. The plurality of first through holes 352 may be formed in the first connection part 351 .
[0110] The second connection part 353 may be longitudinally formed to the other side of the second outer surface 332 . The second connection part 353 may be formed with the second through hole 354 into which the control bar 361 of the fixing part 360 is inserted. The plurality of second through holes 354 may be longitudinally formed to the second connection part 353 .
[0111] The fixing part 360 is a member for fixing the first outer surface 331 and the second outer surface 332 so that the fuel cell (not shown) is mounted in the inner surface 310 . The fixing part 360 may include the control bar 361 . The control bar 361 may be a plurality of insertion parts protruded from one surface of the fixing part 360 . Further, the plurality of control bars 361 having the protruded form may be formed to correspond to the first through hole 352 of the first connection part 351 and the second through hole 354 of the second connection part 353 . The control bar 361 formed as described above may be inserted into the first through hole 352 formed in the first connection part 351 and the second through hole 354 formed in the second connection part.
[0112] The fixing part 360 may be fixed so that the inner surface 310 has a predetermined width by the control bar 361 formed as described above. For example, the fixing part 360 fixes the first outer surface 331 and the second outer surface 332 by inserting the control bar 361 into the first through hole 352 and the second through hole 354 , such that the inner surface 310 may be fixed at a predetermined width.
[0113] FIG. 6 is an exemplified diagram showing a fuel cell module according to another preferred embodiment of the present invention.
[0114] Referring to FIG. 6 , the fuel cell module 300 may include the inner surface 310 , the air supplying hole 320 , the first outer surface 331 , the second outer surface 332 , the air passage 340 , the first connection part 351 , the second connection part 353 , and the fixing part 360 .
[0115] The inner surface 310 is formed to surround the fuel cell (not shown) by directly contacting the outer peripheral surface of the fuel cell (not shown). The inner surface 310 is made of stainless steel but may be thinly formed to have flexible properties. The first inner surface 310 may be formed with the air supplying hole 320 for supplying air to the fuel cell (not shown).
[0116] The first outer surface 331 may be formed to surround a portion of the inner surface 310 while being spaced apart from the first inner surface 310 at a predetermined distance. The first outer surface 331 is made of stainless steel but may be thickly formed to have rigid properties.
[0117] The second outer surface 332 may be formed to surround a portion of the inner surface 310 while being spaced apart from the first inner surface 310 at a predetermined distance. The second outer surface 332 is made of stainless steel but may be thickly formed to have rigid properties.
[0118] The first outer surface 331 and the second outer surface 332 formed as described above may be support the inner surface 310 on which the fuel cell (not shown) is mounted.
[0119] The air passage 340 is a space formed by the inner surface 310 , the first outer surface 331 spaced apart from the inner surface 310 at a predetermined distance, and the second outer surface 332 . The air to be supplied to the fuel cell (not shown) mounted in the fuel cell module 300 may pass through the air passage 340 .
[0120] The plurality of air supplying holes 320 may be formed in the inner surface 310 . The air passing through the air passage 340 may be supplied to the fuel cell (not shown) mounted in the fuel cell module 300 by the air supplying hole 320 .
[0121] The first connection part 351 may be longitudinally formed to the other side of the first outer surface 331 . The first connection part 351 may be inserted with the first through hole 352 into which the control bar 361 of the fixing part 360 is inserted. As shown in FIG. 6 , the plurality of first through holes 352 may be formed by a plurality of columns of the first connection part 351 in a longitudinal direction. For example, the first through hole 352 may include a first inner through hole 355 and a first outer through hole 356 .
[0122] The second connection part 353 may be longitudinally formed to the other side of the second outer surface 332 . The second connection part 353 may be inserted with the second through hole 354 into which the control bar 361 of the fixing part 360 is inserted. As shown in FIG. 6 , the plurality of second through holes 354 may be formed with a plurality of columns of the second connection part 353 in a longitudinal direction. For example, the second through hole 354 may include a second inner through hole 357 and a second outer through hole 358 .
[0123] The fixing part 360 is a member for fixing the first outer surface 331 and the second outer surface 332 so that the fuel cell (not shown) is mounted in the inner surface 310 . The fixing part 360 may include the control bar 361 . The control bar 361 may be a plurality of insertion parts protruded from one surface of the fixing part 360 . As shown in FIG. 6 , the control bar 361 may also be formed with the plurality of columns. For example, the control bar 361 may include a first column control bar 362 , a second column control bar 363 , a third column control bar 364 , and a fourth column control bar 365 .
[0124] The fixing part 360 may be fixed so that the inner surface 310 may control the width of the inner surface 310 by the control bar 361 formed as described above. For example, the first column control bar 362 of the fixing part 360 is inserted into the first outer through hole 356 and when the fourth column control bar 365 is inserted into the second outer through hole 358 , a diameter of the inner surface 310 may be minimized In addition, the second column control bar 363 of the fixing part 360 is inserted into the first inner through hole 355 and when a third column control bar 364 is inserted into a second inner through hole 357 , the diameter of the inner surface 310 may be maximized.
[0125] The number of first through holes 352 and second through holes 354 and the number of control bars 361 are not limited thereto and therefore, may be changed by those skilled in the art.
[0126] FIG. 7 is an exemplified diagram showing a multilayered fuel cell module according to another preferred embodiment of the present invention.
[0127] Referring to FIG. 7 , a multilayered fuel cell module may be formed by stacking at least two fuel cell modules 300 and 300 - 1 in which fuel cells 400 and 410 are mounted.
[0128] Describing an example as shown in FIG. 7 , the first fuel cell module 300 , the second fuel cell module 300 - 1 , the first fuel cell 400 , the second fuel cell 410 , the first connection member 392 , the second connection member 393 , the positive current collector plate 396 , and the negative current collector plate 394 , and an insulating plate 397 are stacked.
[0129] The first fuel cell module 300 is mounted with the first fuel cell 400 . The lower portion of the outer peripheral surface of the first fuel cell module 300 may contact the positive current collector plate 396 . That is, the first fixing part 360 of the first fuel cell module 300 may contact the positive current collector plate 396 . Further, the inner surface of the first fuel cell module 300 may contact one side of the first fuel cell 400 . Here, one side of the first fuel cell 400 may be a bottom surface.
[0130] The first fuel cell 400 is mounted in the first fuel cell module 300 . The bottom surface of the first fuel cell 400 may contact the first fuel cell module 300 . Further, a top surface of the first fuel cell 400 may contact the first connection member 392 .
[0131] The first connection member 392 is a component for transferring the negative current generated from the first fuel cell 400 to the outside of the first fuel cell 400 . The first connection member 392 , which is a member for current collection of the first fuel cell 400 , may be made of metals having electric conductivity. One side of the first connection member 392 is connected with the first fuel cell 400 . That is, one side of the first connection member 392 may be formed so as to be electrically connected to an anode support (not shown) in the first fuel cell 400 . In addition, the other side of the first connection member 392 may contact the lower portion of the outer peripheral surface of the second fuel cell module 300 - 1 .
[0132] The second fuel cell module 300 - 1 is mounted with the second fuel cell 410 . The lower portion of the outer peripheral surface of the second fuel cell module 300 - 1 may contact the first connection member 392 . That is, the second fixing part 390 of the second fuel cell module 300 - 1 may contact the other side of the first connection member 392 . The second fuel cell module 300 - 1 may be electrically connected with the first fuel cell 400 by contacting the first connection member 392 . The inner surface of the second fuel cell module 300 - 1 may contact one side of the second fuel cell 410 . Here, one side of the first fuel cell 400 may be a bottom surface.
[0133] The second fuel cell 410 is mounted in the second fuel cell module 300 - 1 . The bottom surface of the second fuel cell 410 may contact the second fuel cell module 300 - 1 . Further, the top surface of the second fuel cell 410 may contact the second connection member 393 .
[0134] The second connection member 393 is a component for transferring the negative current generated from the second fuel cell 410 to the outside of the second fuel cell 410 . The second connection member 393 , which is a member for current collection of the second fuel cell 410 , may be made of metals having electric conductivity. One side of the second connection member 393 is connected with the second fuel cell 410 . That is, one side of the second connection member 393 may be formed so as to be electrically connected to an anode support (not shown) in the second fuel cell 410 . In addition, the lower side of the second connection member 393 may contact the negative current collector plate 394 .
[0135] The positive current collector plate 396 may collect positive current generated by the first fuel cell 400 and the second fuel cell 410 .
[0136] The negative current collector plate 394 may collect negative current generated by the first fuel cell 400 and the second fuel cell 410 .
[0137] The insulating plate 397 may be formed on both sides of the first fuel cell module 300 and the second fuel cell module 300 - 1 . The insulating plate 397 is pressed to both sides of the first fuel cell module 300 , such that the mounted first fuel cell 400 may better contact the first fuel cell module 300 . In addition, the insulating plate 397 is pressed to both sides of the second fuel cell module 300 - 1 , such that the mounted second fuel cell 410 may better contact the second fuel cell module 300 - 1 .
[0138] As such, the first fuel cell 400 and the second fuel cell 410 may be disposed vertically by the first fuel cell module 300 and the second fuel cell module 300 - 1 . Further, the first fuel cell module 300 and the second fuel cell module 300 - 1 may collect the positive current generated from the first fuel cell 400 and the second fuel cell 410 to the positive current collector plate 396 by serially connecting the first fuel cell 400 and the second fuel cell 410 that are vertically disposed.
[0139] The preferred embodiment of the present invention describes two fuel cell modules and two fuel cells, but is only an example. Therefore, the number of fuel cell modules and fuel cells is not limited thereto. The number of fuel cell modules and fuel cells may be changed by those skilled in the art.
[0140] In addition, the preferred embodiment of the present invention describes the case in which the plurality of fuel cells is connected to one another in series by vertically disposing the plurality of fuel cell modules but is only the example. The plurality of fuel cells may be connected to one another by horizontally disposing the plurality of fuel cell modules. In addition, the plurality of fuel cells may simultaneously be connected to one another in series and in parallel by vertically and horizontally connecting the plurality of fuel cell modules to one another.
[0141] In the preferred embodiment of the present invention, the inner surface is made of the flexible metals and the first outer surface and the second outer surface may be made of rigid metals, which may be expressed in relative terms. That is, a meaning that the metal forming the inner surface is flexible is more flexible than the metal forming the first outer surface and the second outer surface. In addition, a meaning that the metal forming the first outer surface and the second outer surface is rigid is more rigid than the metal forming the inner surface. Here, according to the preferred embodiments of the present invention, the flexibility and the rigidity may be determined at a thickness of an alloy of stainless steel in that the first inner surface and the second inner surface may be made of an alloy of the same stainless steel.
[0142] The fuel cell module according to the preferred embodiment of the present invention is formed to have a hinge structure to facilitate the insertion of the fuel cell. In addition, the inner surface of the fuel cell module according to the preferred embodiment of the present invention is made of the flexible metals, thereby expanding the contact area with the fuel cell as maximally as possible. In addition, the fuel cell module according to the preferred embodiment of the present invention can maximize the contact area with the fuel cell, thereby improving the current collector capacity. Further, the fuel cell module according to the preferred embodiment of the present invention can be made of an alloy of stainless steel to facilitate the oxidation-resistance coating later, thereby improving the durability. In addition, the fuel cell module according to the preferred embodiment of the present invention can be made of an alloy of stainless steel, thereby saving the manufacturing costs.
[0143] The fuel cell module according to the preferred embodiment of the present invention can be formed to have a hinge structure, thereby facilitating the insertion of the fuel cell.
[0144] The inner surface of the fuel cell module according to the preferred embodiment of the present invention can be made of the flexible metals, thereby expanding the contact area with the fuel cell as maximally as possible.
[0145] The fuel cell module according to the preferred embodiment of the present invention can maximize the contact area with the fuel cell, thereby improving the current collector capacity.
[0146] The fuel cell module according to the preferred embodiment of the present invention can be made of an alloy of stainless steel to facilitate the oxidation-resistance coating later, thereby improving the durability.
[0147] The fuel cell module according to the preferred embodiment of the present invention can be made of an alloy of stainless steel, thereby saving the manufacturing costs.
[0148] Although the embodiment of the present invention has been disclosed for illustrative purposes, it will be appreciated that a fuel cell module according to the invention is not limited thereto, and 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.
[0149] Accordingly, any and all modifications, variations or equivalent arrangements should be considered to be within the scope of the invention, and the detailed scope of the invention will be disclosed by the accompanying claims. | Disclosed herein is a fuel cell module. The fuel cell module according to preferred embodiments of the present invention includes: a first support part including a first body part surrounding one side of an outer peripheral surface of a fuel cell and a first connection part formed on one side of the first body part in a longitudinal direction; a second support part including a second body part surrounding the other side of the outer peripheral surface of the fuel cell and the second connection part formed on one side of the second body part in a longitudinal direction; and a fixing part passing through the first connection part and the second connection part to connect and fix the first connection part and the second connection part to each other. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a transport drive, in particular for stage elements, fork-lift trucks and movable platforms, having at least one element which is driven or can be driven and which is integrated in a base area of the stage element.
[0002] Transport drives of this type are known and familiar in many forms and designs. Normally, a motor element or the like is connected to one edge of a stage element in order to move or drive the stage element. The disadvantage with this is that conventional wheels or balls have a point contact with a stage, in particular with an arbitrary base. A stage element of this type supported by wheels is not stable and wobbles as it is moved on a base or on a stage.
[0003] The conventional transport drives for stage elements in addition permit only restricted movement of the stage element in one direction or the other, which is disadvantageous. Moving the stage elements during a performance is therefore not possible.
[0004] DE 30 15 384 A1 shows a theater stage having a stage The chassis of the stage wagon can be driven via an electric motor, it being possible for the chassis to be raised and lowered by means of a lifting cylinder via a complicated construction.
[0005] U.S. Pat. No. 4,127,182 discloses an automatically controlled motor-operated transport car, two of the wheels of the transport car being provided with their own steering and drive elements within the transport car.
[0006] U.S. Pat. No. 5,823,884 describes a similar transport wagon, which has its own driven and steerable rollers.
[0007] DE 298 13 512 U1 discloses a chassis for a displaceable stand, in which the rollers are mounted in a resilient and prestressed manner by means of a gas spring.
[0008] The present invention is therefore based on the object of providing a transport drive for a stage element which eliminates the aforementioned disadvantages and with which the stability of the stage element is to be increased substantially, even during movement, in a simple and cost-effective manner. In addition, independent movement of the stage element on a base, in particular on a stage, is to be ensured.
SUMMARY OF THE INVENTION
[0009] In the present invention, a stage element, a fork-lift truck or a movable platform is assigned at least one transport drive, preferably a plurality of transport drives. The transport drives are preferably arranged in corner regions of a base region. The transport drive itself has an element which is preferably formed in the manner of a roll. This element can be driven actively by a motor element and can be moved with respect to a base in order to raise the stage element or to set the latter down on the base again.
[0010] At the same time, this element or its housing is mounted such that it can be rotated about a vertical axis by means of a further motor element, so that the stage element can be moved in any desired directions and movement sequences on a base by means of appropriate positioning of the element and of the transport drive.
[0011] When the stage element or the fork-lift truck or a movable platform is moved with respect to the base, the elements are extended, so that the base region of the stage element is lifted off the base. As a result of forming the elements as a roll element, there is linear contact between element and base, so that in this way the stability during movement is increased.
[0012] After the stage element has been moved to a desired location, the element is retracted and the stage element is let down and rests securely with its base region on a stage or the base. It is possible for appropriate rubber elements, rubber supports or the like to be provided in the base region in order to increase the stability.
[0013] Brakes or the like are not necessary, so that the stage element stands in a stable manner on the base. This has the advantage that the stage element can also be moved during a performance, it being possible for the movement of the stage element to be controlled and regulated in a preferably wire-free manner. For this purpose, each stage element is assigned its own power sources and control devices, which feed the corresponding motor elements and the control device.
[0014] In this way, the possible applications of appropriate stage elements are increased considerably, so that a plurality of stage elements with a plurality of integrated transport drives can be moved simultaneously, aligned with respect to one another and can be controlled, even during a performance, in the region of the stage or of a base and can be set down stably at any desired points. In this case, the stage elements, the fork-lift trucks or moving platforms can be pivoted or moved about their own axes, about any desired points or moved in linear or circulating movements with respect to the base, depending on the position in the individual transport drive. The individual transport drives are preferably arranged in corner regions of the stage element, the at least one power source preferably being provided in a central region, close to the base region, in order to optimize the centre of gravity. However, the present invention is not restricted to this arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Further advantages, features and details of the invention emerge from the following description of preferred exemplary embodiments and by using the drawing, in which:
[0016] FIG. 1 shows a schematically illustrated partial longitudinal section through a stage element in a position of use, in particular in a base region;
[0017] FIG. 2 shows a schematically illustrated partial longitudinal section of the stage element according to FIG. 1 in another position of use;
[0018] FIG. 3 shows a schematically illustrated plan view of a stage element having a large number of inserted elements for moving, raising and lowering the stage element with respect to a base.
DETAILED DESCRIPTION
[0019] According to FIG. 1 , a stage element R according to the invention has a transport drive F which is inserted into a recess 1 in the stage element R. The transport drive F substantially comprises an element 2 which can be driven actively about an axis B by means of a motor element 3 which is indicated only here and integrated in order to move the stage element R to and fro in an X direction, as FIG. 1 indicates. The motor element 3 drives the element 2 , which can preferably be formed as a drive roll, drive wheel or spherical wheel, precisely and exactly.
[0020] The element 2 is seated in a housing 4 , in which an additional drive element 5 having a lever arm 6 is provided, in order to pivot the element 2 , in particular the roll, which is pivotably mounted in the housing 4 at least by a crossmember 7 , out of the housing 4 and against a base 8 . The drive element 5 drives the lever arm 6 and pivots the element 2 in the Z direction illustrated. In this way, the stage element R can be raised slightly off the base 8 , so that a small gap S is produced between a base region 9 and the base 8 . In this position, the stage element R can be moved, driven by the element 2 .
[0021] Furthermore, the housing 4 is mounted such that it can be rotated about an axis A with respect to the stage element R by a shaft 19 and bearing 10 , at least one gear element 11 being seated on the shaft 19 . An output gear 12 of a further motor element 13 assigned to the recess 1 or to the stage element R engages in said gear element 11 .
[0022] In this way, the element 2 can be rotated exactly and precisely about the axis A such that it can be controlled and regulated, so that any desired direction for movement, in particular for driving the stage element R in the X or Y direction, is possible.
[0023] Furthermore, at least one rechargeable power source 14 , which is connected to a control device 15 , is assigned to the stage element R. Via the power source 14 , the control device 15 , motor elements 3 and 13 and also the drive element 5 are supplied. Here, motor elements 3 and 13 and drive element 5 are connected to one another via bus systems, merely indicated here, and can be driven by the control device 15 . The control device 15 receives the appropriate control signals, preferably in a wire-free manner, from the outside from a central station, not numbered, in order to drive the individual transport drives F in an individual stage element R individually, also differently and also separately.
[0024] If the stage element R is to be moved, then, as indicated in the rest position according to FIG. 2 , the element 2 moves out of the housing 4 against the base 8 and lifts the stage element R, which stands on the base 8 , slightly, so that a gap S is produced in the base region 9 . Then, via respective driving of the axis A of the transport drive F, the element 2 can be driven as desired in terms of direction and speed with respect to the base 8 , depending on the desired direction of movement of the stage element R. In this case, a plurality of transport drives F can be provided in one stage element, in the base region 9 , so that the stage element R can be moved as desired in an X direction and/or Y direction, see FIG. 3 , with respect to the base 8 . Here, the stage element R can itself be moved about any desired selectable points P 1 to P 3 , rotated on the spot, can move around specific selectable points, can be moved on curved paths and in any movements laterally, in a curved fashion or in any other way on the base 8 , in particular a stage.
[0025] Furthermore, in the present invention it is advantageous that, by regulating the drive element 5 by means of the lever arm 6 , the crossmember 7 and therefore the element 2 can be moved into the housing 4 , so that the stage element R can be set down on the base 8 . As a result, the stage element R rests completely on the base 8 , in particular in the base region 9 , and in this way is set up safely and precisely. Appropriate rubber bearings or the like, not illustrated here, can be provided in the base region 9 , in order to ensure high stability of the stage element R on the base 8 , in particular on the stage.
[0026] Furthermore, in the present invention, it has proven to be advantageous to construct the elements 2 as roll elements, so that there is high linear contact with respect to the base 8 ; this likewise leads to high stability, even during operation, in particular even during the movement of the stage element R or during a performance.
[0027] In particular as a result of lowering the stage element R onto the base 8 , a large contact area or standing area of the stage element R is implemented, so that stability is increased. No additional brakes are needed on the stage element, there being no play, for example, to move the stage element R or to set it oscillating.
[0028] In the present invention, it has also proven to be advantageous if a plurality of transport drives F, as illustrated in particular in FIG. 3 , are provided in corner regions 16 , the power source 14 and/or control device 15 being provided in a central region 17 , for example. These are likewise used to optimize a center of gravity of the stage element R. The scope of the present invention is intended likewise to cover, for example, the provision of connecting elements 18 in side walls 20 of the stage element R, which can be used to attach further stage elements. In this way, a transport drive F for a stage element R is provided which offers many kinds of possibilities, so that each stage element R can be moved in any desired manner in an X direction and/or Y direction and can be moved rotatably about any desired points P 1 to P 3 . In this way, remotely controlled stage elements R can be implemented which can be moved into any desired arrangements, even during a performance. | A transport drive, in particular for stage elements, fork-lift vehicles and moving platforms (R), comprising at least one element which is driven or may be driven, integrated in a base region of the stage element (R), whereby the at least one element for raising and lowering the stage element (R) may be driven on a foundation into the stage element (R). | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to short term residual dust suppression, and more particularly to such suppression by application of a dust suppressant composition to a dust-bearing material.
[0003] 2. Description of the Prior Art
[0004] Dust formation from a variety of sources has been a continuing cause of environmental and health concerns. Particular attention has been paid to the dust developed from the handling of coal, but such sources also include, for example, petroleum coke, recycled glass dust, bauxite, and mined minerals such as iron ore, aluminum ore, copper ore, and limestone. Thus, while this specification may refer at times to coal, it should be understood that this discussion is applicable to numerous other dust sources as well.
[0005] Various industries affected by such dust formation have engaged in many efforts to avoid or to alleviate the problem of dust formation that results during handling, conveyance, transportation and even storage of coal and the other dust sources. Typically, such efforts involve the use of water incorporated into a chemical dust suppressant that is applied to the coal or other dust source. Although the categories of dust suppressants have overlapped to some extent in that certain types of suppressants may be reformulated to be applied through a system designed for another type, conventionally a suppressant may fall into the category of a short term dust suppressant, which may be a wet suppressant or a foam suppressant, or a long term residual dust control suppressant. Short term dust suppressants function by coating the source and dust with water. Thus, such suppressants lose their effectiveness upon evaporation of the water. Moreover, their effectiveness generally does not persist beyond one to two impact points; that is, points at which dust is generated during handling or movement of the coal or other source. Examples of wet and foam suppressants are discussed in U.S. Pat. Nos. 4,737,305 to Dohner, 4,836,945 to Kestner, 4,971,720 to Roe, and 5,409,626 to Muth, and in Surfactants and Interfacial Phenomena, 2d Edition, by Milton J. Rosen, Wiley Interscience Publications (1989), all of which are incorporated herein by reference. Conventionally, long term residual dust suppressants control dust by means of the formation of a polymer or binder film over the dust source and thereby persist even after evaporation of water in the suppressant. Such suppressant compositions typically contain a binder composition such as lignosulfonate and a polymeric dispersant. For example, U.S. Pat. No. 5,436,429 to Bennett describes such a long term dust suppressant and mentions in apssing that certain sugar by-products may be as a binder or tackifier. However, binders such as lignosulfonates and polymeric binders or dispersants are costly and create waste disposal problems.
[0006] Wet suppression is based on what is called “wet technology”. This suppression can be as simple as spraying large amounts of water on the coal (or other source) as it travels along a conveyor or drops to a storage pile or transfer bin. However, although water is an effective dust suppressant, its use involves a number of drawbacks, such as adding weight to the coal or other source (which can result in higher costs for transporting the source), development of substantial vapor pressure when the coal or other source is heated or burned, and the absorption and thus wasting of substantial energy as the water vaporizes when the coal or other source is heated or burned.
[0007] As a result, surfactants or “wetters” often are added to the water to reduce the amount of the water needed for dust suppression. Conventional wetters include nonionic epoxide (e.g., ethylene oxide or propylene oxide) derived block co-polymers, alcohols of from about eight to about sixteen carbons ethoxylated with from about four to about ten moles of ethylene oxide (wherein the alcohol may be an aromatic such as alkyl phenol, preferably nonylphenol, which can be ethoxylated with, for example, ten moles ethylene oxide), and branched nonionic surfactants such as branched alpha sulfo ester salts comprising an acid chain and an alcohol chain of from about six to about twelve carbons each, and highly branched alcohol sulfate and alcohol ether sulfate detergents. Generally, the wetter is added to the water in a weight proportion of from about 0.2 to about 5 parts of the wetter to about one thousand parts of water. As this concentration, the wetter acts at the interface between the coal (or other source) and the water to increase the affinity of the coal and water, thereby decreasing the amount of water needed to soak the coal as well as decreasing the time required for the water to penetrate the coal stream.
[0008] Typically, such wet technology is employed to suppress dust Generated at transfer points, areas where the coal falls freely from one point to another (free falls) such as loading points where the coal is dropped into a vessel for transportation, impact points where the coal strikes a surface, and storage areas. The water is applied at the point of dust generation and is applied to the air-borne dust as well as to the source of the dust. If the amount of water added to the coal is sufficiently great, the coal can be prevented from dusting significantly on impact. For such benefits, the water should be added in an amount sufficient to result in a proportion of one to three parts by weight water per one hundred parts by weight wetted coal. However, because the suppressant is effective only through one or two impact points where dust could be generated, repeated applications are necessary, thereby increasing the water content of the wetted coal quickly to seven or eight percent.
[0009] Foam suppressants are applied to form a blanket over the coal or other source to capture and smother dust. Bubbles in the foam suppressant catch the dust particles and so the foam suppressant is effective only until the bubbles break or the layer of foam becomes discontinuous. The foam suppressant is formed by addition of a roamer to water. Conventional foamers include alpha-olefin sulfonates, alkylphenyl sulfonates with long alkyl chains (e.g., eight to sixteen carbons) such as sodium lauryl benzene sulfonate, alcohol sulfates, alcohol ether sulfates, alpha sulfo esters and mixtures of such compounds. Under standard conditions, from about one to about twenty parts by weight roamer is added to about one thousand parts by weight water. The resulting foam has about five to ten percent of the density of the water used in wet technology and so much less water is needed for a foam to provide the same volume of applied dust suppressant as the wet suppressant. Thus, the foam suppressant can be added to the coal in a proportion such that the wetted coal contains 0.2 to 0.5 parts by weight added water per one hundred parts by weight wetted coal. However, as with the wet suppressant, the foam suppressant is effective only through one or two impact points where dust could be generated. Thus, repeated applications are necessary and the water content of the wetted coal increases quickly to several percent.
[0010] As with wet suppressants, the foam suppressants are employed to suppress dust Generated at impact or transfer points, areas where the coal falls freely from one point to another (free falls) such as loading points where the coal is dropped into a vessel for transportation, impact points where the coal strikes a surface, and storage areas. The foam is applied as a curtain or barrier to capture Generated dust. The foam applicator nozzles are located in such a way that the remaining foam and the captured dust are deposited back onto the moving coal stream. This orientation not only prevents dust from escaping into the environment, but also places at least a partial blanket of foam onto the deposited coal, which may prevent dust Generation until bubbles are broken or disrupted by another transfer point. The dust suppression effects of normal foam does not carry over from a previous application point to further impact zone.
[0011] Long term residual dust control suppressants are used to prevent Generation of dust during long term storage or during transportation. Such long term residual suppressants operate by a mechanism very different from those of short term residual suppressants to which the subject invention is directed. In short term residual (wet or foam) suppression, the water eventually evaporates, rendering the suppressant ineffective in suppressing dust over a long term, such as during several months of outdoor storage. Thus, long term residual dust suppressants remain active long after the water evaporates. They ordinarily have some film-forming or tackifying properties. For example, U.S. Pat. No. 4,801,635 to Zinkan et al. describes a long term residual dust suppressant that includes an acrylic polymer and U.S. Pat. No. 4,169,170 to Doeken describes a long term residual dust suppressant that includes an aqueous suspension of asphalt emulsion concentrates or black liquor lignin products as a binder material. Conventionally, water is included in a long term residual suppressant typically not only to provide some dust control during handling prior to storage, but also to promote even spreading as the suppressant is applied. Long term residual dust suppressants often contain wetters or foamers as well to minimize the amount of water needed to apply the suppressant to the coal and are applied directly to the coal in what is known as a “main body treatment”.
[0012] Thus, several problems are associated with conventional wet and foam dust suppression techniques to which the subject invention is directed. For example, each technique involves addition of a substantial amount of water to the coal or other dust source, especially in view of the repeated applications of water-based suppressant necessary to control dust across several impact or transfer points. The resulting high water content of the coal is particularly undesirable in that much dust suppression is performed at fossil fuel power plants. Water added to the fuel results in a portion of the heat output of the coal to be lost to vaporization of the water and so a loss of effective energy. The vaporization of water consumes substantial amounts of heat. Therefore, the addition of such significant amounts of water is particularly troublesome. In addition, the additional water increases the weight of the coal and so increases shipping costs accordingly.
[0013] Because of the substantial disadvantages associated with the addition of such significant amounts of water, the industry has attempted to minimize the amount of water employed in wet and foam suppression techniques. Such attempts typically involve the use of systems for application of the suppressant at each dust producing site instead of a single application that would be intended to last through many transfer points during transport or conveyance of the coal or other dust source. Because the suppressant in the multiple application technique remains effective for only one or two transfer points, such techniques are expensive; they require costly installation of application equipment at several transfer points, impact points and loading or “stack-out” storage sites. In addition, impact sites where dust is generated often are not accessible to the equipment employed in conventional application systems. Thus, such techniques are undesirable.
SUMMARY OF THE INVENTION
[0014] Briefly, therefore, the present invention is directed to a novel method for suppressing dust emanation from a dust-bearing material, comprising applying to the material a dust suppressant that is essentially free of lignosulfonate and comprises molasses-derived protein.
[0015] The present invention is also directed to a novel method for suppressing dust emanation from a dust-bearing material, comprising applying to the material a dust suppressant that is essentially free of polyarcrylates, polyvinyl alcohols and polyacrylamides and comprises molasses-derived protein.
[0016] The present invention is further directed to a novel method for suppressing dust emanation from a dust-bearing material, comprising applying to the material a dust suppressant consisting essentially of water, a composition selected from the group consisting of concentrated molasses solids and condensed molasses solids, and, optionally, a wetting agent, and also optionally, an agent for facilitating application of the dust suppressant to hydrophobic surfaces.
[0017] Among the several advantages found to be achieved by the present invention, therefore, may be noted the provision of an effective and long-term method for suppressing emanation of dust; the provision of suc method that avoids the need for lignosulfonates; and the provision of such method that obviates the need for polymers.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] In accordance with the present invention, it has been discovered that an aqueous dust suppressant comprising molasses-derived protein yields surprisingly effective and long-lasting dust suppression without the need for lignosulfonates or polymers.
[0019] For convenience and shipping economies, the dust suppressant may be prepared by aqueous dilution of a concentrate comprising a derived-derived protein binder. In a preferred embodiment, the binder is concentrated molasses solids (“CMS”). CMS is a de-sugared molasses by-product of the sugar and molasses refining process and is a well known composition in the molasses processing industry. As suggested by its name, it is derived from molasses, which in itself is a product of sugar refining. While molasses has been reported to have been used in combination with coal dust for the formation of briquettes, use of CMS in connection with dust control in formulations of the present invention is unknown to the present inventors. There are a variety of sources of sugar, including sugarcane, sugar beets, citrus, starch and even wood, and molasses may be produced from any of them. And, although any of those sources may be used to produce CMS employed in the dust suppressants discussed herein, cane and beet are two sources of particular interest.
[0020] Molasses and its methods of production from such sources are, of course, well known. Likewise, methods for producing CMS from molasses are well known as well. One such method, wherein sugar is precipitated as a calcium salt, is known as the Steffens process.
[0021] Typically, as received, CMS contains less than about 20% sugar (which is typically predominantly sucrose). The other predominant components other than water of CMS are dissolved minerals in the form of ash, and protein, the latter of which is believed in particular to impart to the mixture the particularly efficacious binding properties desirable for a dust suppressant. An exemplary analysis of the composition of a typical CMS is as follows:
Component Approximate Concentration Total Solids 70.0%* Sucrose 26.5%** Raffinose 5.0%** Nitrogen Compounds (as N) 3.5%** Crude Protein 22.0%** Betaine 8.5%** Amino Acids 0.5%** Ash 30.0%** Other Components 4.0%**
[0022] Alternatively or additionally, the binder may comprise condensed molasses solids, which is sometimes also referred to as “CMS,” but is distinct from the concentrated molasses solids discussed above and referred to herein as CMS. Therefore, to avoid confusion, condensed molasses solids will not be referred to herein as “CMS.” In any event, condensed molasses solids, which is a residue remaining after molasses has been fermented and the alcohol has been distilled off, is also a well-known composition. It is referred to in U.S. Pat. No. 5,536,429, and is available for purchase under the trade designation Brewex.
[0023] The dust suppressant concentrate may comprise solely the binder, but in another embodiment, the binder makes up about 15% by weight to about 95% by weight, such as about 50% by weight to about 70% by weight, of the concentrate. The concentrate may also comprise a wetting agent. The wetting agent may be a single surfactant or it may comprise a plurality of surfactants. Although the wetting agent may make up more than 15% by weight of the concentrate, the economics can suggest a wetting agent concentration in the concentrate of less than about 15% by weight, such as about 2% by weight to about 10% by weight, for example, about 5% by weight to about 7% by weight.
[0024] Anionic and nonionic surfactants have been found to be effective, and cationic surfactants are understood to be suitable as well. In particular, it has been found that use of surfactants the impart to the suppressant a low drop time, such as below about 200 seconds, preferably below about 90 seconds, has yielded especially efficacious dust suppressants. When reference is made herein to “drop time” what is meant is the drop time of coal dust particles of interest in an aqueous solution containing 1% by weight of the surfactant(s) in question and the concentration of binder to be used, as measured by the Walker et al. procedure for measuring coal dust wetting described in Glanville et al., “Coal Dust Phenomena and Control Technology,” University of West Virginia (1952), at p. 395, and illustrated in Example 4, below. The test is based on the rate at which small coal particles piled on a liquid surface below the critical wetting tension descend into the liquid phase. By such testing, for example, DOSS (a 70% aqueous solution of dioctyl sodium sulfosuccinate, CAS# 577-11-7, in diethylene glycol), Neodol 91-6 (also known as Tomadol 91-6, a six-mole ethoxylate of linear C 9 to C 11 alcohols, CAS# 68439-46-3), Polysorbate-80 (a Sorbitan monooleate, CAS# 9005-65-6), and NP-9 (nonylphenol 9 mole ethoxylate, CAS# 9016-45-9) have been found to be well-suited to the subject application.
[0025] The bulk of the concentrate (that is, for example, up to about 85%) may be water, but it has been found that for more hydrophobic surfaces, such as more carbonaceous dust-producing materials, such as petroleum coke, it may be advantageous to include a low HLB surfactant (for example, one having an HLB below 5, such as about 1 or 2), for instance, a diethylene glycol dibutyl ether, in the concentrate. An example of such surfactant is Dowanol DB (diethylene glycol, n-butyl ether, CAS# 112-34-5). The low HLB surfactant may be employed at a concentration on the order of about 1% by weight to about 5% by weight, such as about 2-3% by weight, based on the total weight of the concentrate.
[0026] Although the concentrate ingredients may be mixed together by standard techniques in any order, preferably the water is added to the wetting agent, and then the CMS is added to that resulting mixture. At any desired time, such as after shipment of the concentrate to the situs of application, for example, during the application itself, the concentrate may be diluted with water. In one embodiment, the concentrate is diluted in a proportion of 99 parts by weight water to one part by weight concentrate, such as by means of a proportionate chemical pump, during spray-on application to the dust-generating surface. In such embodiment, the binder and wetting agent concentrations in the dust suppressant therefore are about 1% those of the concentrate. Thus, for example, the concentration of the binder in the dust suppressant in such embodiment may be from about 0.15% by weight to about 1% by weight, such as from about 0.5% by weight to about 0.7% by weight, and the concentration of the wetting agent (which, again, may be a single surfactant or a combination of surfactants), if present, typically is as high as about 0.15% by weight, such as about 0.02% by weight to about 0.1% by weight, for example, from about 0.05% by weight to about 0.07% by weight, based on the total weight of the dust suppressant. Similarly, typical concentrations of sugar (mostly sucrose) in the dust suppressant are less than about 0.25% by weight, or even less than about 0.1% by weight, such as about 0.05% by weight to about 0.2% by weight, typical concentrations of protein in the dust suppressant are from about 0.05% by weight to about 0.2% by weight, and typical concentrations of ash in the dust suppressant are from about 0.1% to about 0.25% by weight, all based on the total weight of the dust suppressant. If present, the low HLB surfactant(s) may have a concentration of about 0.01% by weight to about 0.05% by weight, such as about 0.2-0.25% by weight, based on the total weight of the dust suppressant.
[0027] The dust suppressant may be applied to the dust-generating material by standard techniques, such as by way of a spray manifold designed to produce a uniformly thick foam coat over the dust-generating material. The dust suppressant may be applied in concentrations typically employed with conventional suppressant compositions. By way of illustration, 20 to 100 pounds, such as about 30 to about 60 pounds, for instance, 40 pounds, of the dust suppressant may be applied per ton of dust-generating material. The dust suppressant cures by drying onto the surface of the material. CMS has been found to bind the dust particles to larger particles, preventing the dust particles from becoming airborne. The effect has been discovered to be still apparent even after three weeks at 30% relative humidity at 90° F.
[0028] As noted, the dust suppressant of this invention has been found to provide long term dust suppression without the need for lignosulfonates, polyarcrylates, polyvinyl alcohols, polyacrylamides or any other polymers or other additives conventionally employed for long term dust suppression. Indeed, in many situations, the present formulation has been found to provide even longer term and more effective dust suppression than achieved with such conventional formulations.
[0029] The following examples describe preferred embodiments of the invention. Other embodiments within the scope of the claims herein will be apparent to one skilled in the art from consideration of the specification or practice of the invention as disclosed herein. It is intended that the specification, together with the examples, be considered exemplary only, with the scope and spirit of the invention being indicated by the claims which follow the examples. In the examples all percentages are given on a weight basis unless otherwise indicated.
EXAMPLE 1
[0030] A standard lignosulfonate dust suppressant composition (identified herein as “A-Lig”) comprising 33% by weight lignosulfonate solution, 26% by weight urea solution, 2% by weight DOSS, and 2% by weight Tomadol 91-6 was tested, as was a comparative sample (identified herein as “A-CMS”) of identical composition as A-Lig except that the lignosulfonate solution was replaced with the same mass of beet molasses-derived CMS obtained from Monitor Sugar Company of Michigan and a second comparative sample (identified herein as “B-CMS”) composed of 60% by weight beet molasses-derived CMS, 2% by weight DOSS, and 1.5% by weight polysorbate-80. By way of illustration, A-CMS was prepared by stirring 50% urea (10.4 pounds) from Mississippi Chemical Corporation into the CMS (13.2 pounds) to produce a homogeneous solution and then adding 70% DOSS (a little over 0.75 pounds) obtained from American Emulsions Co., Inc. and Tomadol 91-6 (a little over 0.75 pounds) from Tomah Products, Inc. with stirring with water (about 15 pounds) to the homogeneous solution, and the resulting mixture was stirred for about 15 minutes, thereby producing an opaque homogeneous solution. Each formulation was applied at a 100:1 aqueous dilution with commercial dust suppression equipment to sub-bituminous coal at a rate of 0.03 gallons of the formulated undiluted product per ton of coal and a total 2% moisture addition (that is, the amount of each test composition added to the coal was such that the weight of the water in that amount of added composition was 2% of the weight of the coal treated). In each case, the treated coal was aged at about 30% relative humidity for 28 days at 90° F. (about 32° C.). Samples of the treated coal were removed every seven days and tested according to ASTM D 547-41. The results were as follows, wherein the dust levels are given in mg/m 3 :
Dust Level Dust Suppressant Initial 7 days 14 days 21 days 28 days None (control) 0.67 8.24 13.00 29.85 23.45 A-Lig 0.11 1.85 11.20 11.70 12.80 A-CMS 0.18 4.14 11.94 9.31 10.65 B-CMS 0.135 2.58 8.30 8.76 10.00
[0031] The difference in performance between A-Lig and B-CMS initially and at seven days is not statistically significant; however, the differences at fourteen days and longer are statistically significant.
EXAMPLE 2
[0032] A sufficient quantity of the dust suppressant discussed in Example 1 (B-CMS), a dust suppressant (identified herein as “C-Lig”) comprising 85.04% by weight lignosulfonate solution, 2.3% Dowanol DB and 1.71% NP 9, and a dust suppressant (identified herein as “C-CMS”) comprising 85.04% by weight of the above noted CMS, 2.3% Dowanol DB and 1.71% NP 9, were prepared. The bulk of each formulation was water. By way of illustration, formulation B-CMS was prepared by stirring a mixture of 70% DOSS (a little over 0.75 pounds) from American Emulsions Co., Inc. and Polysorbate-80 (a little over 0.5 pounds) from BASF until the mixture became uniform and then stirring in CMS (24 pounds) from Monitor Sugar Company, and then adding water (almost 15 pounds) to the mixture and stirring the resulting mixture for about half an hour until an opaque homogeneous solution was formed. Each solution was applied to shot coke and tested as described in Example 1, above, with the test running for 21 days. The results were as follows, wherein the dust levels are given in mg/m 3 :
Dust Level Dust Suppressant Initial 7 Days 14 Days 21 Days None (control) 3.60 4.03 7.55 7.58 C-Lig 0.21 2.79 4.26 5.44 C-CMS 0.25 1.96 5.57 4.67 B-CMS 0.21 2.56 3.90 4.63
EXAMPLE 3
[0033] Additional tests were conducted according to the procedures of Examples 1 and 2, above, with the formulations identified therein, as well as a formulation identified as B-Lig of identical composition as B-CMS, except that the CMS was replaced with the same mass of lignosulfonate solution and an additional formulation of a lignosulfonate dust suppressant composition (identified herein as “D-Lig”) comprising 33% by weight lignosulfonate solution, 26% by weight urea solution, and 2% by weight DOSS was tested, as was a comparative sample (identified herein as “D-CMS”) of identical composition as D-Lig except that the lignosulfonate solution was replaced with the same mass of beet molasses-derived CMS obtained from Monitor Sugar Company of Michigan using sub-bituminous coal. The results were as follows, wherein the dust levels are given in mg/m 3 :
Dust Level Dust Suppressant Initial 7 days 14 days 28 days None (control) 14.8 12.7 21.0 19.0 A-Lig 0.7 5.3 15.9 18.5 A-CMS 0.5 6.1 11.3 19.3 B-Lig 1.7 9.6 14.1 20.5 B-CMS 0.8 8.0 9.9 18.6 C-Lig 2.9 15.6 16.8 18.7 C-CMS 1.8 15.8 14.5 21.1 D-Lig 1.7 10.9 20.4 19.9 D-CMS 0.7 7.2 14.8 19.1
EXAMPLE 4
[0034] Drop tests were carried out on dust suppressant samples identified above as A-Lig, A-CMS, B-CMS, D-Lig, D-CMS, and a formulation of 60% by weight CMS, 3% by weight DOSS, 3% by weight Tomadol 91-6, and 34% by weight water, identified herein as “E.” An amount (5 gm) of each sample was diluted with water (495 ml) to produce a test sample. For each test, a sample of dry coal dust (1.1 gm), 200 mesh or finer, was placed gently on the surface of the test sample in a 4-inch diameter 1-L beaker, wherein the sample is at least 2.5 inches below the level of the top of the beaker. The time from the point at which the coal came into contact with the surface of the test sample until all of the coal particles left the surface was measured and recorded. The following results were obtained:
Sample Drop Time (sec.) A-Lig 56 A-CMS 47 B-CMS 189 D-Lig 76 D-CMS 101 E 34
[0035] In view of the above, it will be seen that the several advantages of the invention are achieved and other advantageous results attained.
[0036] As various changes could be made in the above methods and compositions without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense. | A method for suppressing dust emanation from a dust-bearing material comprises applying to the material a dust suppressant that comprises molasses-derived protein. | 2 |
This is a continuation of prior application No. 08/467,039, filed Jun. 6, 1995, now abandoned.
This application includes a microfiche appendix of a source code listing including 1 microfiche having 94 frames.
BACKGROUND OF THE INVENTION
The invention relates in general to a movable barrier operator for opening and closing a movable barrier or door. More particularly, the invention relates to a garage door operator that can learn force and travel limits when installed and can simulate the temperature of its electric motor to avoid motor failure during operation.
A number of garage door operators have been sold over the years. Most garage door operators include a head unit containing a motor having a transmission connected to it, which may be a chain drive or a screw drive, which is coupled to a garage door for opening and closing the garage door. Such garage door openers also have included optical detection systems located near the bottom of the travel of the door to prevent the door from closing on objects or on persons that may be in the path of the door. Such garage door operators typically include a wall control which is connected via one or more wires to the head unit to send signals to the head unit to cause the head unit to open and close the garage door, to light a worklight or the like. Such prior art garage door operators also include a receiver and head unit for receiving radio frequency transmissions from a hand-held code transmitter or from a keypad transmitter which may be affixed to the outside of the garage or other structure. These garage door operators typically include adjustable limit switches which cause the garage door to operate or to halt the motor when the travel of the door causes the limit switch to change state which may either be in the up position or in the down position. This prevents damage to the door as well as damage to the structure supporting the door. It may be appreciated, however, that with different size garages and different size doors, the limits of travel must be custom set once the unit is placed within the garage. In the past, such units have had mechanically adjustable limit switches which are typically set by an installer. The installer must go back and forth between the door, the wall switch and the head unit in order to make the adjustment. This, of course, is time consuming and results in the installer being forced to spend more time than is desirable to install the garage door operator.
A number of requirements are in existence from Underwriter's Laboratories, the Consumer Product Safety Commission and the like which require that garage door operators sold in the United States must, when in a closing mode and contacting an obstruction having a height of more than one inch, reverse and open the door in order to prevent damage to property and injury to persons. Prior art garage door operators also included systems whereby the force which the electric motor applied to the garage door through the transmission might be adjusted. Typically, this force is adjusted by a licensed repair technician or installer who obtained access to the inside of the head unit and adjusts a pair of potentiometers, one of which sets the maximal force to be applied during the closing portion of door operation, the other of which establishes the maximum force to be applied during the opening of door operation.
Such a garage door operator is exemplified by an operator taught in U.S. Pat. No. 4,638,443 to Schindler. However, such door operators are relatively inconvenient to install and invite misuse because the homeowner, using such a garage door operator, if the garage door operator begins to bind or jam in the tracks, may likely obtain access to the head unit and increase the force limit. Increasing the maximal force may allow the door to move passed a binding point, but apply the maximal force at the bottom of its travel when it is almost closed where, of course, it should not.
Another problem associated with prior art garage door operators is that they typically use electric motors having thermostats connected in series with portions of their windings. The thermostats are adapted to open when the temperature of the winding exceeds a preselected limit. The problem with such units is that when the thermostats open, the door then stops in whatever position it is then in and can neither be opened or closed until the motor cools, thereby preventing a person from exiting a garage or entering the garage if they need to.
SUMMARY OF THE INVENTION
The present invention is directed to a movable barrier operator which includes a head unit having an electric motor positioned therein, the motor being adapted to drive a transmission connectable to the motor, which transmission is connectable to a movable barrier such as a garage door. A wired switch is connectable to the head unit for commanding the head unit to open and close the door and for commanding a controller within the head unit to enter a learn mode. The controller includes a microcontroller having a non-volatile memory associated with it which can store force set points as well as digital end of travel positions within it. When the controller is placed in learn mode by appropriate switch closure from the wall switch, the door is caused to cycle open and closed. The force set point stored in the non-volatile memory is a relatively low set point and if the door is placed in learn mode and the door reaches a binding position, the set point will be changed by increasing the set point to enable the door to travel through the binding area. Thus, the set points will be dynamically adjusted as the door is in the learn mode, but the set points will not be changeable once the door is taken out of the learn mode, thereby preventing the force set point from being inadvertently increased, which might lead to property damage or injury. Likewise, the end of travel positions can be adjusted automatically when in the learn mode because if the door is halted by the controller, when the controller senses that the door position has reached the previously set end of travel position, the door will then be commanded by a button push from the wall switch to keep travelling in the same direction, thereby incrementing or changing. The end of travel limits are set by pushing the learn button on the wall switch which causes the door to travel upward and continue travelling upward until the door has travelled as far as the installer wishes it to travel. The installer disables the learn switch by lifting his hand from the button. The up limit is then stored and the door is then moved toward the closed position. A pass point or position normalizing system consisting of a ring-like light interrupter attached to the garage door crosses the light path of an optical obstacle detector signalling instantaneously the position of the door and the door continues until it closes, whereupon force sensing in the door causes an auto-reverse to take place and then raises the door to the up position, the learn mode having been completed and the door travel limits having been set.
The movable barrier operator also includes a combination of a temperature sensor and microcontroller. The temperature sensor senses the ambient temperature within the head unit because it is positioned in proximity with the electric motor. When the electric motor is operated, a count is incremented in the microcontroller which is multiplied by a constant which is indicative of the speed at which the motor is moving. This incremented multiplied count is then indicative of the rise in temperature which the motor has experienced by being operated. The count has subtracted from it the difference between the simulated temperature and the ambient temperature and the amount of time which the motor has been switched off. The totality of which is multiplied by a constant. The remaining count then is an indication of the extant temperature of the motor. In the event that the temperature, as determined by the microcontroller, is relatively high, the unit provides a predictive function in that if an attempt is made to open or close the garage door, prior to the door moving, the microcontroller will make a determination as to whether the single cycling of the door will add additional temperature to the motor causing it to exceed a set point temperature and, if so, will inhibit operation of the door to prevent the motor from being energized so as to exceed its safe temperature limit.
The movable barrier operator also includes light emitting diodes for providing an output indication to a user of when a problem may have been encountered with the door operator. In the event that further operation of the door operator will cause the motor to exceed its set point temperature, an LED will be illuminated as a result of the microcontroller temperature prediction indicating to the user that the motor is not operating because further operation will cause the motor to exceed its safe temperature limits.
It is a principal aspect of the present invention to provide a movable barrier operator which is able to quickly and automatically select end of travel positions.
It is another aspect of the present invention to provide a movable barrier operator which, upon installation, is able to quickly establish up and down force set points.
It is still another aspect of the present invention to provide a movable barrier operator which can determine the temperature of the motor based upon motor history and the ambient temperature of the head unit.
Other aspects and advantages of the invention will become obvious to one of ordinary skill in the art upon a perusal of the following specification and claims in light of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a garage having mounted within it a garage door operator embodying the present invention;
FIG. 2 is a block diagram of a controller mounted within the head unit of the garage door operator employed in the garage door operator shown in FIG. 1;
FIG. 3 is a schematic diagram of the controller shown in block format in FIG. 2;
FIG. 4 is a schematic diagram of a receiver module shown in the schematic diagram of FIG. 3;
FIGS. 5A-B are a flow chart of a main routine that executes in a microcontroller of the control unit;
FIGS. 6A-G are a flow diagram of a learn routine executed by the microcontroller;
FIGS. 7A-B are flow diagrams of a timer routine executed by the microcontroller;
FIGS. 8A-B are flow diagrams of a state routine representative of the current and recent state of the electric motor;
FIGS. 9A-B are a flow chart of a tachometer input routine and also determines the position of the door on the basis of the pass point system and input from the optical obstacle detector;
FIGS. 10A-C are flow charts of the switch input routines from the switch module; and
FIG. 11 is a schematic diagram of the switch module and the switch biasing circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and especially to FIG. 1, more specifically a movable barrier door operator or garage door operator is generally shown therein and referred to by numeral 10 includes a head unit 12 mounted within a garage 14. More specifically, the head unit 12 is mounted to the ceiling of the garage 14 and includes a rail 18 extending therefrom with a releasable trolley 20 attached having an arm 22 extending to a multiple paneled garage door 24 positioned for movement along a pair of door rails 26 and 28. The system includes a hand-held transmitter unit 30 adapted to send signals to an antenna 32 positioned on the head unit 12 and coupled to a receiver as will appear hereinafter. An external control pad 34 is positioned on the outside of the garage having a plurality of buttons thereon and communicates via radio frequency transmission with the antenna 32 of the head unit 12. A switch module 39 is mounted on a wall of the garage. The switch module 39 is connected to the head unit by a pair of wires 39a. The switch module 39 includes a learn switch 39b, a light switch 39c, a lock switch 39d and a command switch 39e. An optical emitter 42 is connected via a power and signal line 44 to the head unit 12. An optical detector 46 is connected via a wire 48 to the head unit 12. A pass point detector 49 comprising a bracket 49a and a plate structure 49b extending from the bracket has a substantially circular aperture 49c formed in the bracket, which aperture might also be square or rectangular. The pass point detector is arranged so that it interrupts the light beam on a bottom leg 49d and allows the light beam to pass through the aperture 49c. The light beam is again interrupted by the leg 49e, thereby signalling the controller via the optical detector 46 that the pass point detector attached to the door has moved past a certain position allowing the controller to normalize or zero its position, as will be appreciated in more detail hereinafter.
As shown in FIGS. 2 and 3, the garage door operator 10, which includes the head unit 12 has a controller 70 which includes the antenna 32. The controller 70 includes a power supply 72 which receives alternating current from an alternating current source, such as 110 volt AC, and converts the alternating current to +5 volts zero and 24 volts DC. The 5 volt supply is fed along a line 74 to a number of other elements in the controller 70. The 24 volt supply is fed along the line 76 to other elements of the controller 70. The controller 70 includes a super-regenerative receiver 80 coupled via a line 82 to supply demodulated digital signals to a microcontroller 84. The receiver is energized by a line 86 coupled to the line 74. The microcontroller 84 is also coupled by a bus 87 to a non-volatile memory 88, which non-volatile memory stores set points and other customized digital data related to the operation of the control unit. An obstacle detector 90, which comprises the emitter 42 and infrared detector 46 is coupled via an obstacle detector bus 92 to the microcontroller 84. The obstacle detector bus 92 includes lines 44 and 48. The wall switch 39 is connected via the connecting wires 39a to a switch biasing module 96 which is powered from the 5 volt supply line 74 and supplies signals to and is controlled by the microcontroller 84 via a bus 100 coupled to the microcontroller 84. The microcontroller 84, in response to switch closures, will send signals over a relay logic line 102 to a relay logic module 104 connected to an alternating current motor 106 having a power take-off shaft 108 coupled to the transmission 18 of the garage door operator. A tachometer 110 is coupled to the shaft 108 and provides a tachometer signal on a tachometer line 112 to the microcontroller 84, the tachometer signal being indicative of the speed of rotation of the motor.
The power supply 72 includes a transformer 130 which receives alternating current on leads 132 and 134 from an external source of alternating current. The transformer steps down the voltage to 24 volts and feeds 24 volts to a pair of capacitors 138 and 140 which provide a filtering function. A 24 volt filtered DC potential is supplied on the line 76 to the relay logic 104. The potential is fed through a resistor 142 across a pair of filter capacitors 144 and 146, which are connected to a 5 volt voltage regulator 150, which supplies regulated 5 volt output voltage across a capacitor 152 and a Zener diode 154 to the line 74.
Signals may be received by the controller at the antenna 32 and fed to the receiver 80. The receiver 80 includes a pair of inductors 170 and 172 and a pair of capacitors 174 and 176 that provide impedance matching between the antenna 32 and other portions of the receiver. An NPN transistor 178 is connected in common base configuration as a buffer amplifier. Bias to the buffer amplifier transistor 178 is provided by resistors 180 and 181. A resistor 188, a capacitor 190, a capacitor 192 and a capacitor 194 provide filtering to isolate a later receiver stage from the buffer amplifier 178. An inductor 196 also provides power supply buffering. The buffered RF output signal is supplied on a line 200, coupled between the collector of the transistor 178 and a receiver module 202 which is shown in FIG. 4. The lead 204 feeds into the unit 202 and is coupled to a biasing resistor 220. The buffered radio frequency signal is fed via a coupling capacitor 222 to a tuned circuit 224 comprising a variable inductor 226 connected in parallel with a capacitor 228. Signals from the tuned circuit 224 are fed on a line 230 to a coupling capacitor 232 which is connected to an NPN transistor 234 at its base 236. The transistor has a collector 240 and emitter 242. The collector 240 is connected to a feedback capacitor 246 and a feedback resistor 248. The emitter is also coupled to the feedback capacitor 246 and to a capacitor 250. The line 210 is coupled to a choke inductor 256 which provides ground potential to a pair of resistors 258 and 260 as well as a capacitor 262. The resistor 258 is connected to the base 236 of the transistor 234. The resistor 260 is connected via an inductor 264 to the emitter 242 of the transistor. The output signal from the transistor is fed outward on a line 212 to an electrolytic capacitor 270.
As shown in FIG. 3, the capacitor 270 capacitively couples the demodulated radio frequency signal to a bandpass amplifier 280 to an average detector 282 which feeds a comparator 284. The comparator 284 also receives a signal directly from the bandpass amplifier 280 and provides a demodulated digital output signal on the line 82 coupled to the P32 pin of the Z86E21/61 microcontroller 84. The microcontroller 84 is energized by the power supply 72 and also controlled by the wall switch 39 coupled to the microcontroller by the leads 100.
From time to time, the microcontroller will supply current to the switch biasing module 96.
The microcontroller operates under the control of a main routine as shown in FIGS. 5A and 5B. When the unit is powered up, a power on reset is performed in a step 300, the memory is cleared and a check sum from read-only memory within the microcontroller 84 is tested. In a step 302, if the check sum and the memory prove to be correct, control is transferred to a step 304, if not, control is transferred back to the step 300. The last non-volatile state, which is indicative of the state of the operator, that is whether the operator indicated the door was at its up limit, down limit or in the middle of its travel, is tested for in a step 304 and if the last state is a down limit, control is transferred to a step 306. If it was an up limit, control is transferred to a step 308. If it was neither a down nor an up limit, control is transferred to a step 310. In the step 306, the position is set as the down limit value and a window flag is set. The operation state is set as down limit. In a step 308, the position is set as up, the window flag is set and the operation state is set as up limit. In the step 310, the position is set as outside the normal range, 6 inches below the secondary up limit. The operation state is set as stopped. Control is transferred from any of steps 306, 308 and 310 to a step 312 where a stored simulated motor temperature is read from the non-volatile memory 88. The temperature of a printed circuit board positioned within the head unit is read from the temperature sensor 120 which is supplied over a line 120a to the microcontroller. In order to read the PC board temperature, a pin P20 of the microprocessor 84 is driven high, causing a high potential to appear on a line 120b which supplies a current through the RTD sensor 120 to a comparator 120c. A capacitor 120d connected to the comparator and to the temperature sensor, is grounded and charges up. The other input terminal to the comparator has a voltage divider 120e connected to it to supply a reference voltage of about 2.5 volts. Thus, the microcontroller starts a timer running when it brings line 120b high and interrogates a line 120f to determine its state. The line 120f will be driven high when the temperature at the junction of the RTD 120 and the capacitor 120d exceeds 2.5 volts. Thus, the time that it takes to charge the capacitor through the resistance is indicative of the temperature within the head unit and, in this manner, the PC board temperature is read and if the temperature as read is greater than the temperature retrieved from the non-volatile memory, the temperature read from the PC board is then stored as the motor temperature.
In a step 314, constants related to the receipt and processing of the demodulated signal on the line 82 are initialized. In a step 316, a test is made to determine whether the learn switch 39b had been activated within the last 30 seconds. If it has not, control is transferred back to the step 314.
In a step 318, a test is made to determine whether the command switch debounce timer has expired. If it has, control is transferred to a step 320. If it is not, control is transferred back to the step 314. In the step 320, the learn limit cycle is begun as will be discussed in more detail as to FIGS. 6A through 6G. The main routine effectively has a number of interrupt routines coupled to it. In the event that a falling edge is detected on the line 112 from the tachometer, an interrupt routine related to the tachometer is serviced in the step 322. A timer interrupt occurs every 0.5 millisecond in a step 324 as shown in FIGS. 7A through 7B.
The obstacle detector 90 generates a pulse every 10 milliseconds during the time when the beam from the infrared emitter 42 has not been interrupted either by the pass point system 49 or by an obstacle, in a step 326 following which the obstacle detector timer is cleared in a step 328.
As shown in FIGS. 10A through 10C, operation of the switch biasing module 96 is controlled over the lines 100 by the microcontroller 84. The microcontroller 84, in the step 340, tests to determine whether an RS232 digital communications mode has been set. If it has, control is transferred to a step 342, as shown in FIG. 10C, testing whether data is stored in an output buffer to be output from the microcontroller 84. If it is, control is transferred to a step 344 outputting the next bit, which may include a start bit, from the output buffer and control is then transferred back to the main routine. In the event that there is no data in the data buffer, control is transferred to the step 346, testing whether data is being received over lines 100. If it is being received, control is transferred to a step 348 to receive the next bit into the input buffer and the routine is then exited. If not, control is transferred to a step 350. In the step 350, a test is made to determine whether a start bit for RS232 signalling has been received. If it has not, control is transferred to a return step 352. If it has, control is transferred to a step 354 in which a flag is set indicating that the start bit has been received and the routine is exited. As shown in FIG. 10A, if the response to the decision block 340 is no, control is transferred to a decision step 360. The switch status counter is incremented and then a test is determined as to whether the contents of the counter are 29. If the switch counter is 29, control is transferred to a step 362 causing the counter to be zeroed. If the counter is not 29, control is transferred to a step 364, testing for whether the switch status is equal to zero. If the switch status is equal to zero, control is transferred to a step 366. In a step 366, a current source transistor 368, shown in FIG. 11, is switched on, drawing current through resistors 370 and 372 and feeding current out through a line 39a connected thereto to the switch module 39 and, more specifically, to a resistor 380, a 0.10 microfarad capacitor 382, a 1 microfarad capacitor 384, a 10 microfarad capacitor 386 and a switch terminal 388. The switch 39e is coupled to the switch terminal 388. The switch 39d may be selectively coupled to the capacitor 386. The switch 39b may be selectively coupled to the capacitor 384. The switch 39c may be selectively coupled to the capacitor 382. A light emitting diode 392 is connected to the resistor 380. Current flows through the resistor 380 and the light emitting diode 392 back to another one of the lines 39a and through a field effect transistor 398 to ground. In step 402, the sense input on a line 100 coupled to the transistor 398 is tested to determine whether the input is high. If the input is high immediately, that is indicative of the fact that switches 39b through 39e are all open and in a step 404, debounce timers are decremented for all switches and a got switch flag is set and the routine is exited in the event that the test of step 402 is negative. Control is then transferred to a step 406 testing after 10 microseconds if the sense in output on the line 100 connected to the field effect transistor 398 is high, which would be indicative of the switch 39c having been closed. If it is high, in step 408 the worklight timer is incremented, all other switch timers are decremented, the got switch flag is set and the routine is exited. In the event that the decision in step 406 is in the negative, control is transferred to a step 410 and the routine is exited. In the event that the decision from step 364 is in the negative, control is transferred to a step 412 wherein the switch status is tested as to whether it is equal to one. If it is, control is transferred to a step 414 testing whether the sensed input on the line 100 connected to the field effect transistor is high. If it is, control is transferred to step 416 to test the got switch flag, after which in a step 418, the learn switch debouncer is incremented, all other switch counters are decremented, the got switch flag is set and the routine is exited. In the event that the answer to step 414 or 416 is in the negative, control is transferred to a return step 420.
In the event that the answer to step 412 is in the negative, control is transferred to a step 422, as shown in FIG. 10B. A test is made as to whether the switch status is equal to 10. If it is, control is transferred to a step 424 where the sense out input is tested as high.
Thus, the charging rate for the capacitors which, in effect, is sensed on the line 100 connected to the field effect transistor 398 which is coupled to ground, is indicative of which of the switches is closed because the switch 39c has a capacitor that charges at 10 times the rate of the capacitor 384 connected to 39b and 100 times the rate of the capacitor 386 selectively couplable to switch 39d.
After the switch measurement has been made, the transistor 368 is switched non-conducting by the line 368b and the field effect transistor 398 is switched non-conducting by a line 450 connected to its gate. A transistor 462, coupled via a resistor 464 to a line 466, is switched on, biasing a transistor 468 on, causing current to flow through a diagnostic light emitting diode 470 to a field effect transistor 472 which is switched on via a voltage on a line 474. In addition, the capacitors 386, 384 and 382, which may have been charged are discharged through the field effect transistor 472.
In order to perform all of the switching functions after the step 424 has been executed, control is transferred to a step 510 testing whether the got switch flag has been cleared. If it has, control is transferred to a step 512 in which the command timer is incremented and all other timers are decremented and the got switch flag is set and the routine is exited. If the got switch flag has not been cleared as detected in the step 510, the routine is exited in the step 514. In the event that the sense input is measured as being high in the step 424, control is transferred to a step 516 where the vacation or lock flag counter is incremented and all other counters are decremented. The got switch flag is set and the routine is exited. In the event that the switch status equal 10 test in the step 422 is indicated to be no, control is then transferred to a step 520 testing whether the switch status is 11. If the switch status is 11, indicating that the routine has been swept through 11 times, control is transferred to a step 522 in which the field effect transistors 398 and 472 are both switched on, providing ground pads on both sides of the capacitors causing the capacitors to discharge and the routine is then exited. In the event that the step 520 test is negative, control is transferred to a step 524 testing whether the routine has been executed 15 times. If it has, control is transferred to a step 526 to determined if the bit which controls the status of light emitting diode 470, the diagnostic light emitting diode, has been set. If it has not been set, control is transferred to a step 528 wherein both transistors 368 and 468 are switched on and both the field effect transistors 398 and 472 are switched off. In order to test for short circuits between the source and drain electrodes of the field effect transistors 398 and 472 which might cause false operation signals to be supplied on the lines 100 to the microcontroller 84, resulting in inadvertent operation of the electric motor. The routine is then exited. In the event that the test in step 526 indicates that the diagnostic LED bit has been set, control is transferred to a step 530. In the step 530, the transistors 468 and 472 are switched on allowing current to flow through the diagnostic LED 470. In the event that the test in step 524 is negative, a test is made in a step 532 as to whether the routine has been executed 26 times. If it has not, the routine is exited in a step 534. If it has, both of the field effect transistors 398 and 372 are switched on to connect all of the capacitors to ground to discharge the capacitors and the routine is exited.
As shown in FIGS. 7A and 7B, when the timer interrupt occurs as in step 324, control is transferred to a step 550 shown in FIG. 7A wherein a test is made to determine whether a 2 millisecond timer has expired. If it has not, control is transferred to a step 552 determining whether a 500 millisecond timer has expired. If the 500 millisecond timer has expired, control is transferred to a step 554 testing whether power has been switched on through the relay logic 104 to the electric motor 106. If the motor has been switched on, control is transferred to a step 556 testing whether the motor is stalled, as indicated by the motor power having been switched on and by the fact that pulses are not coming through on the line 112 from the tachometer 110. In the event that the motor has stalled, control is transferred to a step 558. In the step 558 the existing motor temperature indication, as stored in one of the registers of the microcontroller 84, has added to it a constant which is related to a motor characteristic which is added in when the motor is indicated to be stalled. In the event that the response to the step 556 is in the negative, indicating that the motor is not stalled, control is transferred to a step 560 wherein the motor temperature is updated by adding a running motor constant to the motor temperature. In the event that the response to the test in step 554 is in the negative, indicating that motor power is not on and that heat is leaking out of the motor so that the temperature will be dropping, the new motor temperature is assigned as being equal to the old motor temperature, less the quantity of the old motor temperature, minus the ambient temperature measured from the RTD probe 120, the whole difference multiplied by a thermal decay fraction which is a number.
All of steps 558, 560 and 562 exit to a step 564 which test as to whether a 15 minute timer has timed out. If the timer has timed out, control is transferred to a step 566 causing the current, or updated motor temperature, to be stored in a non-volatile memory 88. If the 15 minute timer has not been timed out, control is transferred to a step 568, as shown in FIG. 7B. Step 566 also exits to step 568. A test is made in the step 568 to determine whether a obstacle detector interrupt has come in via step 326 causing the obstacle detector timer to have been cleared. If it has not, the period will be greater than 12 milliseconds, indicating that the obstacle detector beam has been blocked. If the obstacle detector beam, in fact, has been blocked, control is transferred to a step 570 to set the obstacle detector flag.
In the event that the response to step 568 is in the negative, the obstacle detector flag is cleared in the step 572 and control is transferred to a step 574. All operational timers, including radio timers and the like are incremented and the routine is exited.
In the event that the 2 millisecond timer tested for in the step 550 has expired, control is transferred to a step 576 which calls a motor operation routine. Following execution of the motor operation routine, control is transferred to the step 552. When the motor operation routine is called, as shown in FIG. 8A, a test is made in a step 580 to determine the status of the motor operation state variable which may indicate if the up limits or down limit has been reached. If the up limit or the down limit have been reached, the motor is causing the door to travel up or down, the door has stopped in mid-travel or an auto-reverse delay indicating that the motor has stopped in mid-travel and will be switching into up travel shortly. In the event that there is an auto-reverse delay, control is transferred to a step 582, when a test is made for a command from one of the radio transmitters or from the wall control unit and, if so, the state of the motor is set indicating that the motor has stopped in mid-travel. Control is then transferred to a step 584 in which 0.50 second timer is tested to determine whether it has expired. If it has, the state is set to the up travel state following which the routine is exited in the step 586. In the event that the operation state is in the up travel state, as tested for in step 580, control is transferred to a step 588 testing for a command from a radio or wall control and if the command is received, the motor operational state is changed to stop in mid-travel. Control is transferred to a step 590. If the force period indicated is longer than that stored in an up array location, indicated by the position of the motor. The state of the door is indicated as stopped in mid-travel. Control is then transferred to a step 592 testing whether the current position of the door is at the up limit, then the state of the door is set as being at the up limit and control is transferred to a step 594 causing the routine to be exited, as shown in FIG. 8B.
In the event that the operational state tested for in the step 580 is indicated to be at the up limit, control is transferred to a step 596 which tests for a command from the radio or wall control unit and a test is made to determine whether the motor temperature is below a set point for the down travel motor temperature threshold. The state is set as being a down travel state. If the temperature value exceeds the threshold or set point temperature value, an output diagnostic flag is set for providing an output indication in another routine. Control is then transferred to a step 598, causing the routine to be exited. In the event that the down travel limit has been reached, control is transferred to a step 600 testing for whether a command has come in from the radio or wall control and, if it has, the state is set as auto-reverse and the auto-reverse timer is cleared. Control is then transferred to a step 602 testing whether the force period, as indicated, is longer than the force period stored in the down travel array for the current position of the door. Auto-reverse is then entered at step 582 on a later iteration of the routine. Control is transferred to a step 604 to test whether the position of the door is at the down limit position and the pass point detector has already indicated that the door has swept past the pass point, the state is set as a down limit state and control is transferred to a step 606 testing for whether the door position is at the down limit position and testing for whether the pass point has been detected. If the pass point has not been detected, the motor operational state is set to auto-reverse, causing auto-reverse to be entered in a later routine and control is transferred to a step 608, exiting the main routine.
In the event that the block 580 indicates that the door is at the down limit, control is transferred to a step 610, testing for a command from the radio or wall control and testing the current motor temperature. If the current motor temperature is below the up travel motor temperature threshold, then the motor state variable is set as equal to up travel. If the temperature is above the threshold or set point temperature, a diagnostic code flag is then set for later diagnostic output and control is transferred to a return step 612. In the event that the motor operational state is indicated as being stopped in mid-travel, control is transferred to a step 614 which tests for a radio or wall control command and tests the motor temperature value to determine whether it is above or below a down travel motor temperature threshold. If the motor temperature is above the travel threshold, then the door is left stopped in mid-travel and the routine is returned from in step 616.
In the event that the learn switch has been activated as tested for in step 316 and the command switch is being held down as indicated by the positive result from the step 318, the learn limit cycle is entered in step 320 and transfers control to a step 630, as shown in FIG. 6A, In step 630, the maximum force is set to a minimum value from which it can later be incremented, if necessary. The motor up and motor down controllers in the relay logic 104 are disabled. The relay logic 104 includes an NPN transistor 700 coupled to line 76 to receive 24 to 28 volts therefrom via a coil 702 of a relay 704 having relay contacts 706. A transistor 710 coupled to the microcontroller is also coupled to line 76 via a relay coil 714 and together comprise an up relay 718 which is connected via a lead 720 to the electric motor 106. A down transistor 730 is coupled via a coil 732 to the power supply 76. The down relay 732 has an armature 734 associated with it and is connected to the motor to drive it down. Respective diodes 740 and 742 are connected across coils 714 and 732 to provide protection when the transistors 710 and 730 are switched off. In the step 632, both the transistors 710 and 730 are switched off, interrupting either up motor power or down motor power to the electric motor 106 and the microcontroller delays for 0.50 second. Control is then transferred to a step 634, causing the relay 704 to be switched on, delivering power to an electric light or worklight 750 associated with the head unit. The up motor relay 716 is switched on. A 1 second timer is also started which inhibits testing of force limits due to the inertia of the door as it begins moving. Control is then transferred to a step 636, testing for whether the 1 second timer has timed out and testing for whether the force period is longer than the force limit setting. If both conditions have occurred, control is transferred to a step 640 as shown in FIG. 6B. If either the 1 second timer has not timed out or the force period is not longer than the force limit setting, control is transferred to a step 638 which tests whether the command switch is still being held down. If it is, control is transferred back to step 636. If it is not, control is transferred to the step 640. In step 640, both the up transistor 710 and the down transistor 730 are causing both the up motor and down motor command from the relay logic to be interrupted and a delay of 0.50 second is taken and the position counter is cleared. Control is then transferred to a step 641 in which the transistor 730 is commanded to switch on, starting the motor moving down and the 1 second force ignore timer is started running. A test is made in a step 642 to determine whether the command switch has been activated again. If it has, the force limit setting is increased in a step 644 following which control is then transferred back to the step 632. If the command switch is not being held down, control is then transferred to a step 646, testing whether the 1 second force ignore timer has timed out. The last 32 rpm pulses indicative of the force are ignored and a force period from the previous pulse is accepted as the down force. Control is then transferred to a step 648 and a test is made to determine whether the movable barrier is at the pass point as indicated by the pass point detector 49 interacting with the optical detector 46. Control is then transferred to a step 650. The position counter is complemented and the complemented value is stored as the up limit following which the position counter is cleared and a pass point flag is set. Control is then transferred back to the step 642. In the event that the result of the test in step 648 is negative, control is transferred to a step 652 which tests whether the 1 second force delay timer has expired and whether the force period is greater than the force limit setting, indicating that the force has exceeded. If both of those conditions have occurred, control is transferred to a step 654 which tests whether the pass point flag has been set. If it has not been set, control is transferred to a step 656, wherein the position counter is complemented and the complemented value is saved as the up limit and the position counter is cleared. In the event that the pass point flag has been set, control is transferred to a step 658. In the event that the test in step 652 has been negative, control is transferred to a step 660 which tests the value of the obstacle reverse flag. If the obstacle reverse flag has not been set, control is transferred to the step 642 shown on FIG. 6B. If the flag has been set, control is transferred to the step 654.
In a step 658, both transistors 710 and 730 are switched off interrupting up and down power from the relays to the electric motor 106 and halting the motor and the microcontroller 84 then delays for 0.50 second. Control is then transferred to a step 660. In step 660, the transistor 710 is switched on switching on the up relay causing the motor to be turned to drive the door upward and the 1 second force ignore timer is started. Control is transferred to a decision step 662 testing for whether the command switch is set. If the command switch is set, control is transferred back to the step 664 causing the force limit setting to be increased, following which control is transferred to the step 632, interrupting the motor outputs. If the command switch has not been set, control is transferred to the step 664 causing the maximum force from the 33rd previous reading to be saved as the up force, following which control is transferred to a decision block 666 which tests for whether the 1 second force ignore timer has expired and whether the force period is longer than the force limit setting. If both conditions are true, control is transferred to a step 668. If not, control is transferred to a step 670 which tests for whether the door position is at the up limit. If the door position is at the up limit, control is transferred to the step 668, switching off both of the motor outputs to halt the door and delaying for 0.50 second. If the position tested in step 670 is not at the upper limit, control is transferred back to the step 662. Following step 668 control is transferred to step 674, where the down output is turned on and the 1 second force ignore timer is started. Control is then transferred to the step 676 during which the command switch is tested. If the command switch is set, control is transferred back to the step 644 causing the force limit setting to be increased and ultimately to the step 632 which switches off the motor outputs and delays for 0.50 second. If the command switch has not been set, control is transferred to a step 678. If the position counter indicates that the door is presently at a point where a force transition normally occurs or where force settings are to change, and the 1 second force ignore timer has expired, the 33rd previous maximum force is stored and the down force array is filled with the last 33 force measurements. Control is then transferred to a step 680 which tests for whether the obstacle detector reverse flag has been set. If it has not been set, control is transferred to a step 682 which tests for whether the 1 second force ignore timer has expired and whether the force period is longer than the force limit setting. If both those conditions are true, control is transferred to a step 684 which tests for the pass point being set. If the pass point flag was not set, control is transferred to the step 688. In the event that the obstacle reverse flag is set, control is also transferred to the step 686, and then to 688. In the event that the decision block 682 is answered in the negative, control is transferred back to the step 676. If the pass point flag has been set as tested for in the step 684, control is transferred to the step 686 wherein the current door position is saved as the down limit position. In step 688, both the motor output transistors 710 and 730 are switched off, interrupting up and down power to the motor and a delay occurs for 0.50 second. Control is then transferred to the step 690 wherein the up transistor 710 is switched on, causing the up relay to be actuated, providing up power to the motor and the 1 second force ignore timer begins running. In the step 692, a test is made for whether the command has been set again. If it has, control is transferred back to the step 644, as shown in FIG. 6B, and following that to the step 632, as shown in FIG. 6A. If the command switch has not been set, control is transferred to the step 694 which tests for whether the position counter indicates that the door is at a sectional force transition point or barrier and the 1 second force ignore timer has expired. If both those conditions are true, the maximum force from the last sectional barrier is then loaded. Control is then transferred to a decision step 696 testing for whether the 1 second force ignore timer has timed out and whether the force period is indicated to be longer than the force period limit setting. If both of those conditions are true, control is then transferred to a step 698 causing the motor output transistors 710 and 730 to be switched off and all data is stored in the non-volatile memory 88 and the routine is exited. In the event that decision is indicated to be in the negative from the decision step 696, control is transferred to a step 697 which tests whether the door position is presently at the up limit position. If it is, control is then transferred to the step 698. If it is not, control is transferred to the step 692.
In the event that the rpm interrupt step 322, as shown in FIG. 5B, is executed, control is then transferred to a step 800, as shown in FIG. 9A. In step 800, the time duration from the last rpm pulse from the tachometer 110 is measured and saved as a force period indication. Control is then transferred to a decision block. Control is transferred to the step 802, in which the operator state variable is tested. In the event that the operator state variable indicates that the operator is causing the door to travel down, the door is at the down limit or the door is in the auto-reverse mode, control is transferred to a step 804 causing the door position counter to be incremented. In the event that the door operator state indicates that the door is travelling upward, has reached its up limit or has stopped in mid-travel, control is transferred to a step 806 which causes the position counter to be decremented. Control is then transferred to a decision step 808 in which the pass point pattern testing flag is tested for whether it is set. If it is set, control is transferred to a step 810 which tests a timer to determine whether the maximum pattern time allotted by the system has expired. In the event that the pass point pattern testing flag is not set, control is transferred to a step 812, testing for whether the optical obstacle detector flag has been set. If it is not set, the routine is exited in a step 814. If the obstacle detector flag has been set, control is transferred to a step 816 wherein the pattern testing flag is set and the routine is exited. In the event that the maximum pattern time has timed out, as tested for in the step 810, control is transferred to a step 820 wherein the optical reverse flag is set and the routine is exited. In the maximum pattern time has not expired, a test is made in a step 822 for whether the microcontroller has sensed from the obstacle detector that the beam has been blocked open within a correct timing sequence indicative of the pass point detection system. If it has not, the routine is exited in a step 824. If it has, control is transferred to a step 826. Testing for whether a window flag has been set. As to whether the rough position of the door would indicate that the pass point should have been encountered. If the window flag has been set, control is transferred to a step 828, testing for whether the position is within the window flag position. If it has, control is transferred to a step 832, causing the position counter to be cleared or renormalized or zeroed, setting the window flag and set a flag indicating that the pass point has been found, following which the routine is exited. In the event that the position is not within the window as tested for in step 828, the obstacle reverse flag is set in a step 830 and the routine is exited. In the event that the test made in step 326 indicates that the window flag has not been set, control is then transferred directly to the step 832.
While there has been illustrated and described a particular embodiment of the present invention, it will be appreciated that numerous changes and modifications will occur to those skilled in the art, and it is intended in the appended claims to cover all those changes and modifications which fall within the true spirit and scope of the present invention. | A movable barrier operator includes a wall control switch module having a learn switch thereon. The switch module is connectable to a control unit positioned in a head of a garage movable barrier operator. The head unit also contains an electric motor which is connected to a transmission for opening and closing a movable barrier such as a garage door. The switch module includes a plurality of switches coupled to capacitors which, when closed, have varying charge and discharge times to enable which switch has been closed. The control unit includes an automatic force incrementing system for adjusting the maximal opening and closing force to be placed upon the movable barrier during a learn operation. Likewise, end of travel limits can also be set during a learn operation upon installation of the unit. The movable barrier operator also includes an ambient temperature sensor which is used to derive a motor temperature signal, which motor temperature signal is measured and is used to inhibit motor operation when further motor operation exceeds or is about to exceed set point temperature limits.
CROSS-REFERENCE TO RELATED APPLICATIONS | 4 |
BACKGROUND OF THE INVENTION
[0001] Advances in technology have provided a full gamut of recording options for many different purposes. Travel is one of the most popular events to be recorded. However, photographing or video recording from a commercial carrier, especially an air carrier is limited. Many times, the recorded images are blurred, have a reflection from a window, or are too far away to capture the image of interest. In addition, a passenger's view of an interesting object or feature may be blocked or out of sight.
[0002] Maintenance or operational personnel of a commercial carrier are under similar limitations of having a partially or completely blocked view of operational items of interest. Many times, a mechanical or operational problem is not known until the damage is severe, which could cause major delays and safety issues.
SUMMARY OF THE INVENTION
[0003] Embodiments include a camera viewing system, which includes a first array of cameras distributed atop a carrier that is configured to record or stream video content about a radial view of the carrier. The camera viewing system also includes a second array of cameras distributed about a first side of the carrier that is configured to record or stream video content from a front and back first side view of the carrier. The camera viewing system also includes a third array of cameras distributed about a second side of the carrier that is configured to record or stream video content from a front and back second side view of the carrier. The camera viewing system also includes a router configured to route the recorded and streamed video content to the carrier, and a transmitter configured to transmit the recorded and streamed video content to a satellite for routing to a receiver for subsequent display away from the carrier. The camera viewing system also includes a plurality of displays configured to receive camera manipulation instructions from multiple parties and display associated results, via respective graphical user interfaces (GUIs).
[0004] Embodiments also include a redundant camera viewing system, which includes a first array of cameras distributed atop a carrier that is configured to record or stream video content about a radial view of the carrier. The redundant camera viewing system also includes a second array of cameras distributed about a first side of the carrier that is configured to record or stream video content from a front and back first side view of the carrier. The redundant camera viewing system also includes a third array of cameras distributed about a second side of the carrier that is configured to record or stream video content from a front and back second side view of the carrier. The redundant camera viewing system also includes a router configured to route the recorded and streamed video content to the carrier. The first, second, and third arrays of cameras contain multiple cameras directed towards a similar viewing area, and are configured to capture duplicate video content and assign to individual viewers.
[0005] Embodiments also include a method of displaying video content to passengers or personnel of a carrier. The method includes receiving live or recorded video content captured from a plurality of arrays of cameras located about a top and one or more sides of a carrier. The method also includes routing the video content to display screens within the carrier for viewing by the passengers or the personnel of the carrier. The method also includes receiving instructions to manipulate one or more of the cameras from the passengers or the personnel of the carrier, via one or more graphical user interfaces (GUIs). The method also includes sending results of the received instructions to the passengers or the personnel of the carrier on a priority basis, and displaying the results of the received instructions onto the respective GUIs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
[0007] FIG. 1A illustrates a commercial passenger aircraft according to one example;
[0008] FIG. 1B illustrates different views of a mounted camera according to one example;
[0009] FIG. 2 illustrates an exterior view of a commercial passenger aircraft according to one example;
[0010] FIG. 3 illustrates a system by which camera images are captured, routed, and broadcast according to one example;
[0011] FIG. 4 illustrates various air carriers according to one example;
[0012] FIG. 5 illustrates a train and water carrier according to one example;
[0013] FIG. 6 is a flowchart for a method of displaying video content according to one example;
[0014] FIG. 7 illustrates a layout of modules and communication lines of a camera system according to one example; and
[0015] FIG. 8 illustrates exemplary computer hardware used in a camera system according to one example.
[0016] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] FIG. 1A illustrates a commercial passenger aircraft 100 and an associated camera 110 , which has a very high resolution and focus in order to film and record all scenes from different angles of the ground and the sky during a flight from the time of taking off until the aircraft lands. Videos and photographs from a commercial passenger aircraft can be shown to different viewing audiences, including but not limited to flight and ground personnel, riding passengers, advertising agencies, and weather monitoring agencies. The videos and photographs can also be used as evidence in the event of an accident or a crime. FIG. 1A illustrates only one camera 110 . However, multiple cameras grouped within multiple camera arrays are mounted at various locations about the commercial passenger aircraft 100 , as will be described later. FIG. 1B illustrates that a camera mounted on an underside of a passenger aircraft can capture a panoramic or wide angle view from the aircraft, or a small scope view, either of which can be manually or automatically controlled.
[0018] FIG. 2 illustrates an exterior view of a commercial passenger aircraft and the placement of various cameras of a camera viewing system. The passenger aircraft 200 has a generally tubular-shaped fuselage 201 . Wings 203 and 211 are mounted on either side of the fuselage 201 . Engines 202 and 212 are attached to the underside of each respective wing 203 and 211 . Flaps 207 and 209 are located at the back side of each respective wing 203 and 211 . A tail 213 and rear stabilizer 216 are located at the back end of the fuselage 201 .
[0019] A top camera array 121 is mounted on the top of the fuselage 201 . A bottom camera array 122 is mounted on the bottom of the aircraft fuselage 201 . A side camera array is mounted on each side of the passenger aircraft 200 at 123 A and 123 B. The side cameras 123 A and 123 B can be mounted within the passenger cabin. The camera arrays 123 A and 123 B could also be attached to the fuselage 201 . The side camera arrays 123 A and 123 B are aimed along the leading edge of the wings 203 and 211 to provide a good view of the wings 203 and 211 and engines 202 and 212 .
[0020] Each camera array 121 , 122 , 123 A, and 123 B contains multiple cameras that are aimed or directed at areas of interest. For example, the top camera array 121 may include respective cameras that are directed towards the front of the fuselage 201 , towards the rear of the fuselage 201 , and towards each side of the fuselage 201 to encompass a complete radial view from the top of the fuselage 201 . Embodiments include more than one camera aimed in a particular direction if the four cameras do not cover a complete radial view. The bottom camera array 122 contains at least four cameras to cover views of the front, back, and two sides of the fuselage 201 . In addition, a camera could also be aimed or directed downward towards the earth. Side camera arrays 123 A and 123 B contain at least two cameras to cover a front side view and a rear side view. More than two cameras in each of the side camera arrays 123 A and 123 B could be included to fully encompass the side views of the fuselage 201 . All cameras of the camera arrays could be mounted to a base to provide adjustment of the direction of view of each camera. The combined camera arrays 121 , 122 , 123 A and 123 B provide a view of the wings, engines, tail, and other critical components of the aircraft 200 .
[0021] The top camera array 121 and the bottom camera array 122 could be mounted to the exterior of the fuselage 201 . Therefore, the camera arrays would be enclosed within an aerodynamic, durable, and transparent housing. The transparent housing material includes but is not limited to polymethyl methacrylate, hardened glass, acrylic, cellulose acetate butyrate, or polystyrene. The two side camera arrays 123 A and 123 B may be mounted within the cabin and could be enclosed in a transparent housing.
[0022] The cameras may include still-photograph cameras that are timed to capture an image at periodic times. The cameras may also include a camcorder to capture video clips, either continuously or at periodic times. The cameras could be either wire-connected or wirelessly connected to a controlling system, such as a central processing unit. The photographs and/or video clips are captured and routed to be displayed instantaneously for live viewing, and can also be saved for later viewing.
[0023] FIG. 3 illustrates a system by which the images are captured, routed, and broadcast. A passenger aircraft 300 has multiple cameras 310 mounted, such as the top, bottom, and side camera arrays described above. The captured photographs and videos are sent to a satellite 320 , which routes the captured photographs and videos to a receiver 330 located at or near ground level. The receiver 330 in turn broadcasts the captured photographs and videos to miscellaneous display devices, such as but not limited to a television 340 , a desktop computer 350 , or a laptop or other mobile computer 360 . One or more of the display devices can include an interactive graphical user interface (GUI) for inputting operating instructions and display instructions, as well as receiving display results. The viewing audiences of the received photographs and videos include but are not limited to the airlines company for the particular commercial passenger aircraft, airline governing agencies, such as the Federal Aviation Administration (FAA), weather monitoring agencies, advertising agencies, travel agencies, and mechanical maintenance personnel.
[0024] FIG. 3 illustrates images that are captured, routed via satellite to a receiver, and broadcast to various user devices located at or near ground level. Another embodiment would allow passengers to view the images from one or more cameras of interest during a flight, which could be displayed on a monitor on the backside of the seat directly in front of each passenger. A selection of one or more cameras to view can be made individually for each passenger. Selection could be made via a touch screen on a display monitor, as an example. An embodiment could also provide larger mobile screens to passengers for viewing larger and/or multiple images. A connection port could be available for passengers to connect their own mobile devices to the camera views. The images could be live images from any one of the mounted cameras from the camera arrays, or the images could be previously recorded and played back at the passenger's discretion. The multiple images could also be scrolled at a scrolling speed set by the passenger, rather than viewing in split screens or manually scrolling through the images.
[0025] Embodiments described herein provide an air carrier passenger with several options during a flight. There may be certain times during a flight that are of more interest than other times. For instance, a flight take-off and a flight landing may be of interest to many passengers, or passing over a major landmark, such as a mountain or a lake. Accordingly, in selected embodiments, passengers may input information indicating which items they are most interested in seeing while on the flight, such as lakes, mountains, baseball stadium, etc, and the system will provide the passenger with this view at the appropriate time during the flight. For example, after the user identifies landmarks or items of interest, the system can determine which of these locations will be in the flight path and at which time based on analyzing geographical data and/or GPS data in conjunction with flight path data as would be understood by on of ordinary skill in the art. The system can then determine when the plane is at a particular location of interest to the user at which point the system will switch to a particular camera to capture the particular view for the passenger. Further, the cameras of the system can be programmed to rotate to a particular location based on timing information received from the passenger or predetermined by the system. For example, a passenger may wish to watch the sunset during their flight and can provide input as to at which time they want a camera to capture the sunset. Alternatively, or in addition to, the system may obtain information in advance as to when sunset occurs during their flight path and either offer this information to the passenger as an optional viewing criterion or can automatically capture the sunset for display to the passengers. Timing information of the sunset or other events can be determined in advance by the system by web crawling particular databases to obtain this information as would be understood by one of ordinary skill in the art.
[0026] The multiple images provided by the mounted camera arrays provide multiple views and angles that would not be possible to view directly without the aid of cameras. For example, it is not possible to observe things out of both sides of the aircraft simultaneously. In addition, there is no view for any passenger directly in front of or behind the air carrier. Multiple camera views allow a passenger to see all views and all sides of a feature or event. An interactive display, such as a GUI would allow a passenger to independently select which cameras to view and what order or what display format in which to view them. Another embodiment provides passengers the luxury of viewing recorded features of interest from many perspectives during periods of non-interesting events.
[0027] An embodiment also allows passengers to zoom in, via the bottom camera directed downwards, while passing over an area of interest. Passengers could also change the direction of view of other individual cameras, as well as zoom in and out. Still another embodiment would provide passengers the option of downloading an application onto a mobile smart device that will save selected images onto the mobile device for viewing after the flight. These and other viewing selections could be made via a GUI that is allocated to each passenger.
[0028] An advertising or marketing agency could also capitalize on airline cameras capturing still photographs or videos while passing over an area of interest. An embodiment includes photographing certain landmark features of a city for purposes of displaying the captured photographs or videos to riding passengers. For example, captured photographs of the white house and the capitol building while flying over Washington, DC could be displayed to riding passengers. This could be a marketing arrangement made between the airlines company and the Chamber of Commerce of Washington, DC. Another embodiment includes capturing photographs of displayed billboards while flying over a particular area, as arranged between the airlines company and the entity responsible for the displayed billboard. The captured billboard photographs could be spot-displayed to flying passengers at the beginning or during display of non-advertising video content. Further, information know about the passengers, such as travel habits, travel locations and expenditures, could be utilized to filter billboards detected by the captured by the airline cameras such that targeted billboard or advertising information could be sent to particular customers which a higher chance of having a marketing effect.
[0029] Flight personnel on the commercial passenger aircraft during a flight may also be interested in the captured photographs and videos. Flight personnel could have a continuous or frequently updated live view of the aircraft from the front to the rear of the aircraft and from the upper side and from the lower side of the aircraft. Therefore, any abnormalities could be quickly spotted and dealt with accordingly. The multiple images could be displayed simultaneously to provide an instant picture of the entire aircraft, or the multiple images could be scrolled onto a monitor for viewing one at a time. In addition, each camera could be manually adjusted in terms of projection view and zooming in or out to obtain a better view of a particular feature of interest.
[0030] Manipulation of some of the cameras by selected passengers would be possible during certain times of the flight. Any of the cameras would need to be “reserved” for manipulation, since any one camera could not be manipulated by multiple users. A distribution of available cameras could be made on a priority basis, ticket basis (first-class versus economy), and/or payment basis. In selected embodiments, the distribution of camera time can be determined based on who booked the flight first, how often the passenger has flown with a particular airline and/or whether the passenger is a member of the airline or airline program. Further, it is envisioned that games may be played on the GUI consoles within planes and that passengers may play games against each other for fun. Accordingly, the distribution of camera time can also be determined based on winners or losers of various in-flight games. In addition, certain cameras that are primarily used by flight and ground crews may only be available intermittently for passenger viewing. One or more of the cameras could be assigned for individual use, including but not limited to passengers, flight personnel, ground personnel, certain agency users, government users, or private company users.
[0031] Redundant cameras could be made a part of the camera viewing system to alleviate some or all of the above-described problems. For example, the airlines may want a dedicated viewing of at least some of the cameras, without them being manipulated by any of the passengers. Redundant cameras could provide multiple cameras with the same or similar viewing area to multiple audiences. For example, some cameras with a similar view could be configured and/or programmed for carrier personnel use, while other cameras with the similar view could be configured and/or programmed for passenger use. This would allow independent manipulation of multiple cameras by multiple audiences of the same or similar viewing area. The number of redundant cameras could be determined based upon a market demand.
[0032] Weather monitoring agencies may also want dedicated cameras to capture all views from all angles. In addition, weather monitoring agencies could mount other measuring devices to be used with the recorded images, such as pressure, temperature, and wind-measuring devices. Natural phenomena, such as flooding or a volcano could also be monitored by a weather monitoring agency or other agency. Redundant cameras could also provide backup images during any down time of certain cameras. Certain agencies, such as travel agencies or advertising agencies may want a combination of their own dedicated cameras, plus the option of using any passenger recorded events. Law enforcement agencies could use some of the video content in solving a crime. Aviation government agencies could use some of the video content to obtain information from a downed air carrier.
[0033] A large number of redundant cameras would provide the option of passenger manipulation of the cameras to a large number of passengers, rather than just a select few, such as first-class passengers. Different options would be available to an air carrier to provide camera viewing to most or all of its passengers, with or without a fee. In addition, one or more cameras could be reserved with the purchase of a ticket. Also, certain cameras could be owned or leased by a particular person or agency. During a flight, those owned or leased cameras could be operated by an employee or contractor of the respective agency.
[0034] Embodiments described above have been described in the context of a commercial air carrier with public or private passengers. However, any air carrier could be used to implement embodiments described herein. For example, a weather agency, news agency, or law enforcement agency may own the air carrier, in addition to the mounted cameras and any other related equipment or measuring devices. Air carriers illustrated in FIGS. 1-3 are some examples. Other air carriers include but are not limited to airplanes, helicopters, and military aircraft, such as the aircraft vehicles illustrated in FIG. 4 . Embodiments described herein could be used in various military air carriers for surveillance purposes, such as fighter jets or drones. Other air carriers include unmanned aerial vehicles, un-motorized aerial vehicles, remote controlled aerial vehicles, and hot air balloons.
[0035] Embodiments described herein can also be used for carriers other than air carriers. FIG. 5 illustrates a passenger train and a passenger cruise-liner. Other examples of passenger carriers include but are not limited to buses and smaller water vehicles. A land or water vehicle may not need a camera aimed directly downwards, such as that used by an air carrier. However, all other mounted cameras, their uses, and their advantages could be realized with a land or water carrier, which are contemplated by embodiments described herein. For example, cameras mounted at different locations at different angles to a train, bus, or ship would provide the advantages of capturing multiple views that would not be possible for an individual to view directly. In addition, commercial trains, buses, and ships or barges could profit from the advantages of enhanced surveillance of the carrier and its mechanical and operational facilities. Captured video images for any carriers could be a live stream of video content and/or replay of recorded video images.
[0036] FIG. 6 is a flowchart, which illustrates a method 600 of displaying video content to passengers or personnel of a carrier. Live or recorded video content that is captured from a plurality of arrays of cameras located about a top and one or more sides of a carrier is received in step S 610 . Live or recorded video content captured from a plurality of arrays of cameras located on a bottom surface of the carrier may also be received. The carrier could be one of an air carrier, a train, a water vessel, or a bus. However, other carriers that incorporate the methods and systems of embodiments described herein are hereby contemplated. The video content is routed to display screens within the carrier for viewing by the passengers or the personnel of the carrier in step S 620 . Instructions to manipulate one or more of the cameras are received from the passengers or the personnel of the carrier, via one or more graphical user interfaces (GUIs) in step S 630 . Received instructions could include one or more of changing a camera direction, zooming a camera in or out, streaming live video content, or displaying recorded video content. Results of the received instructions are sent to the passengers or the personnel of the carrier on a priority basis in step S 640 . The results of the received instructions are displayed onto the respective GUIs in step S 650 .
[0037] The method 600 could also include receiving live or recorded duplicate video content from multiple cameras, and receiving independent instructions to manipulate the multiple cameras receiving the duplicate video content. The method 600 could also include receiving independent instructions to manipulate the multiple cameras from one or more of an advertising agency, a news agency, a law enforcement agency, or a weather agency.
[0038] FIG. 7 is an illustration of a layout of modules and communication lines between the modules of a camera system 700 according to embodiments described herein. A central processing unit (CPU) 710 controls the communication between the modules of the camera system 700 . The CPU 710 includes a memory component 711 , and a router 712 . The router 712 routes video content from camera array modules 720 to associated display modules 740 . FIG. 7 illustrates multiple camera array modules 720 a - 720 n , which transfer video content to the CPU 710 through associated bus lines 760 . The individual camera array modules could represent a camera array located atop a carrier, another two camera arrays could be located on either side of the carrier, and another camera array could be located on the underside of the carrier. However, several other locations and combinations of locations of camera array modules are contemplated by embodiments described herein.
[0039] The router 712 routes video content to various display modules, such as display module 730 , which could be a dedicated display module, such as a display dedicated to carrier personnel through a bus line 770 . The router 712 also routes video content to one or more display modules 740 a - 740 n , which could be display modules intended for passenger viewing through associated bus lines 780 . However, other display modules or groups of display modules are contemplated by embodiments described herein. The display modules could be interactive modules, in which instructions could be input and returned results displayed, such as a graphical user interface (GUI). In addition to receiving instructions and displaying results through display modules 740 , the video content can be transmitted by a transmitter module 750 to a remote location. An example of a transmission system was illustrated in FIG. 3 . Instructions from the CPU 710 to the transmitter module 750 are transferred through communications line 790 .
[0040] FIG. 8 illustrates exemplary computer hardware used in a camera system according to embodiments described herein. In FIG. 8 , the camera system includes a CPU 800 which performs the processes described above. The process data and instructions may be stored in memory 802 , which may be separate from or in combination with the memory 711 illustrated in FIG. 7 . These processes and instructions may also be stored on a storage medium disk 804 such as a hard drive (HDD) or portable storage medium or may be stored remotely. Further, the claimed embodiments are not limited by the form of the computer-readable media on which the instructions of the inventive process are stored. For example, the instructions may be stored on CDs, DVDs, in FLASH memory, RAM, ROM, PROM, EPROM, EEPROM, hard disk or any other information processing device with which the camera system communicates, such as a server or computer.
[0041] Further, the claimed embodiments may be provided as a utility application, background daemon, or component of an operating system, or combination thereof, executing in conjunction with CPU 800 and an operating system such as Microsoft Windows 7 , UNIX, Solaris, LINUX, Apple MAC-OS and other systems known to those skilled in the art.
[0042] CPU 800 may be a Xenon or Core processor from Intel of America or an Opteron processor from AMD of America, or may be other processor types that would be recognized by one of ordinary skill in the art. Alternatively, the CPU 800 may be implemented on an FPGA, ASIC, PLD or using discrete logic circuits, as one of ordinary skill in the art would recognize. Further, CPU 800 may be implemented as multiple processors cooperatively working in parallel to perform the instructions of the inventive processes described above.
[0043] The camera system in FIG. 8 also includes a network controller 806 , such as an Intel Ethernet PRO network interface card from Intel Corporation of America, for interfacing with network 88 . As can be appreciated, the network 88 can be a public network, such as the Internet, or a private network such as an LAN or WAN network, or any combination thereof and can also include PSTN or ISDN sub-networks. The network 88 can also be wired, such as an Ethernet network, or can be wireless such as a cellular network including EDGE, 3G and 4G wireless cellular systems. The wireless network can also be WiFi, Bluetooth, or any other wireless form of communication that is known.
[0044] The camera system further includes a display controller 808 , such as a NVIDIA GeForce GTX or Quadro graphics adaptor from NVIDIA Corporation of America for interfacing with display 810 , such as a Hewlett Packard HPL2445w LCD monitor. A general purpose I/O interface 812 interfaces with a keyboard and/or mouse 814 as well as a touch screen panel 816 on or separate from display 810 . General purpose I/O interface 812 also connects to a variety of peripherals 818 including printers and scanners, such as an OfficeJet or DeskJet from Hewlett Packard.
[0045] A sound controller 820 is also provided in the camera system, such as Sound Blaster X-Fi Titanium from Creative, to interface with speakers/microphone 822 thereby providing sounds and/or music.
[0046] The general purpose storage controller 824 connects the storage medium disk 804 with communication bus 826 , which may be an ISA, EISA, VESA, PCI, or similar, for interconnecting all of the components of the camera system. A description of the general features and functionality of the display 810 , keyboard and/or mouse 814 , as well as the display controller 808 , storage controller 824 , network controller 806 , sound controller 820 , and general purpose I/O interface 812 is omitted herein for brevity as these features are known.
[0047] Numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. | A camera viewing system and method includes a first array of cameras distributed atop a carrier to record or stream video content about a radial view of the carrier. A second array of cameras distributed about a first side of the carrier records or streams video content from a front and back first side view of the carrier. A third array of cameras distributed about a second side of the carrier records or streams video content from a front and back second side view of the carrier. A router routes the recorded and streamed video content to the carrier, and a transmitter transmits the recorded and streamed video content to a satellite for routing to a receiver for subsequent display away from the carrier. A plurality of displays receives camera manipulation instructions from multiple parties and displays associated results, via respective GUIs. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to flow control devices and, in particular, to a flow control having a flow control washer that maintains a generally constant volumetric flow rate through a liquid stream despite fluctuations in supply pressure.
2. Description of the Related Art
Flow controls are commonly used in appliances such as dishwashers, drinking fountains, and water softeners to compensate for variations in water supply pressure. The typical flow control comprises an annular flexible flow control washer mounted in a conduit such that water flowing through the conduit must flow through a central orifice in the flow control washer. The flow control washer and its support in the conduit are configured so that the orifice constricts as the water pressure increases, thereby maintaining a generally constant volumetric liquid flow rate through the conduit despite variations in supply pressure. A flow control of this general type has been used in water softeners as is detailed in U.S. Pat. No. 4,210,532 to Loke and in U.S. Pat. No. 5,162,080 to Dragger.
Flow controls of the above-mentioned type tend to be very noisy in operation, possibly due to cavitation caused by the pressure drop across the washer and/or to vibrations of the washer itself. In fact, in the case of a water softener, the whistling noise generated by the flow of water through the flow control can often proprogate through the pipes and be heard throughout much of the building.
This noise problem has been recognized and addressed, but never satisfactorily. For instance, U.S. Pat. No. 5,226,446 to Cooper proposes a rather complex anticavitation arrangement disposed downstream of the flow control washer. U.S. Pat. No. 3,250,342 to Petry proposes an expansion duct having apertures to recycle a portion of the fluid flow. U.S. Pat. No. 3,712,341 to Constantin proposes a flow separator for separating a downstream fluid influx from an upstream fluid flow. All of these arrangements are relative complex, are relatively expensive to manufacture and install, and are of questionable effectiveness.
In view of the foregoing, it would be desirable to provide a flow control that solves the noise problems associated with prior flow controls in a simple and effective manner.
SUMMARY OF THE INVENTION
The invention, which is defined by the claims set out at the end of this disclosure, is intended to solve at least some of the problems noted above. In accordance with a first aspect of the invention, the above-identified need is satisfied by providing a flow control comprising a conduit and flow control washer disposed in the conduit between its inlet and its outlet. “Conduit,” as used herein, means an enclosed passageway capable of receiving a flow control washer. An ambient fluid passageway opens into the conduit, preferably at a location just downstream of the flow control washer, to permit a gas (typically ambient air) to enter a liquid stream flowing from the flow control washer. The admission of the gas into this liquid stream reduces noise generated by liquid flow through the flow control washer. Gas induction and noise reduction capabilities may be enhanced by admitting the gas into a low pressure region of a venturi located in the conduit adjacent the flow control washer. The venturi may be formed integrally with the conduit or provided as a separate insert fitted in the conduit.
A method of reducing noise in a flow control is also provided. In the method, liquid flows through a flow control washer of a flow control conduit at a volumetric flow rate that remains generally constant, despite pressure fluctuations in the flowing liquid, due to operation of the flow control washer. A gas (typically ambient air) is drawn into the liquid flow to reduce the noise that would otherwise be generated by operation of the flow control.
The flow control can be used in any application where the flow rate is controlled within a particular pressure range. Examples of uses for the flow control include, but are not limited to, water softeners, water fountains, eye washes, dishwashers, and safety showers. If used on conjunction with a simple on/off valve, it can also be used do measure or dispense a given volume of fluid, without having to make volumetric measurements, simply by relying the flow control to maintain a desired fluid flow rate therethrough and automatically or manually closing the valve at the appropriate time. Hence, if a flow control maintains a flow rate therethrough at 2 gpm, 20 gallons can be reliably measured or dispensed simply by closing an associated valve after 10 minutes of flow through the flow control.
These and other objects, advantages, and features of the invention will become apparent to those skilled in the art from the detailed description and the accompanying drawings. It should be understood, however, that the detailed description and accompanying drawings, while indicating preferred embodiments of the present invention, are given by way of illustration and not of limitation.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred exemplary embodiments of the invention are illustrated in the accompanying drawings, in which like reference numerals represent like parts throughout and in which:
FIG. 1 is a sectional elevation view of a vessel incorporating a flow control constructed in accordance with a first embodiment of the invention;
FIG. 2 is a side elevation view of a second, more practical embodiment of a flow control in accordance with the invention;
FIG. 3 is a sectional perspective view of the flow control of FIG. 2;
FIG. 4 is a perspective view of a third preferred embodiment of a flow control in accordance with the invention;
FIG. 5 is a sectional elevation view of the flow control of FIG. 4, taken generally along line 5 — 5 in FIG. 4;
FIG. 6 is a sectional elevation view of the flow control of FIG. 4, taken generally along line 6 — 6 in FIG. 5; and
FIG. 7 is a perspective view of a water softener that incorporates a flow control constructed in accordance with the invention.
Before explaining embodiments of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments or being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting.
DETAILED DESCRIPTION
1. Resume
Pursuant to the invention, a flow control is provided that is configured to reduce or even eliminate noise associated with previous flow controls. The flow control includes a bore that draws a gas into a liquid stream in the vicinity of a flow control washer of the flow control for purposes of noise reduction. It has been discovered that the noises caused by the flow of liquid through the washer can be reduced or even eliminated simply by including a small bore in the flow control just downstream of the flow control washer for the admission of the gas, typically ambient air.
2. System Overview and First Embodiment of Flow Control
Referring to the drawings and initially to FIG. 1, a vessel 10 is schematically illustrated that employs a flow control 12 that is constructed in accordance with a preferred embodiment of the invention. The vessel 10 may be any system or structure from which water or another liquid is intended to flow at a generally constant volumetric flow rate. Examples of such structures are drinking fountains and eye washers. The vessel 10 could also be a backwashable filter, in which case the flow control 12 would be used in a control valve used to help control the backwashing process. The vessel 10 includes an outlet port 14 for the discharge of liquid, typically water, to another location, typically the ambient atmosphere. The liquid could also be discharged to a pressurized outlet. The outlet port 14 is coupled to a discharge line (not shown) by an elbow fitting 16 . The elbow fitting 6 includes an annular lip 18 around its outer periphery that rests against a shoulder 20 of the outlet port 14 . An O-ring 22 , which is disposed in a groove 24 in the outer periphery of the elbow 16 , forms a seal between an inner periphery of the outlet port 14 and the elbow 16 .
The flow control 12 may be provided as a standalone item as in the illustrated embodiment or as part of a more complex valve assembly. The flow control 12 also may be formed integrally with an existing conduit or inserted into that conduit. In the embodiment of FIG. 1, the flow control 12 is inserted in a lower, vertical leg 26 of the elbow fitting 16 . The flow control 12 of the embodiment of FIG. 1 comprises 1) a tubular conduit in the form of a plastic tube 28 and 2) a flow control washer 30 mounted in the tube 28 . The tube 28 has an inlet 32 , an outlet 34 , and an outer peripheral surface 36 . The outer peripheral surface 36 is press-fit into the lower leg 26 of the elbow 16 and sealed to the elbow 16 by an O-ring 38 mounted on a groove 40 in the outer peripheral surface 36 of the tube 28 . As is conventional, the flow control washer 30 comprises an annular elastomeric washer having an outer periphery 42 and a center orifice 44 . The outer periphery 42 is held in place within the tube 28 and sealed against an inner peripheral surface 46 of the tube 28 in a conventional manner. Alternatively, and as is more typically the case in flow controls, the washer 12 could simply rest on a shelf-like seat and be sealed to the seat during operation by the pressure differential thereacross. The center orifice 44 forms a flow path for water or another liquid through the washer 30 . The flow control washer 30 is configured so that the diameter of the orifice 44 constricts generally proportionally as the pressure drop across the washer 30 increases, thereby maintaining the volumetric flow rate of liquid through the washer 30 at least generally constant regardless of variations in supply pressure. Hence, fluid travels through the orifice 44 in the flow control washer 30 at a generally constant volumetric flow rate, exiting the tube 28 , and is discharged from the fitting 16 .
The flow control 12 also includes a passageway 52 that admits a gas into the flow control 12 in a low pressure region of the flow control. The passageway 52 extends through the elbow 16 , through the tube 28 and into the interior of the tube 28 at a location downstream of the flow control washer 30 . The passageway 52 of the embodiment comprises a simple bore drilled through the fitting 16 and tube 28 . The bore 52 permits a gas to enter the liquid stream flowing from the flow control washer 30 , as is shown by arrow 53 . The gas will typically comprise ambient air and, therefore, will hereafter be referred to as “air” for the sake of convenience. It has been observed that the flow of liquid through the flow control washer 30 causes a venturi effect that produces low pressure that draws air into the bore 52 and discharges a frothy air/liquid mixture from the outlet 46 . The manner in which the bore 52 actually eliminates the noise that is associated with the flow control washer 30 is unknown. While applicant does not wish to be restricted to a particular theory of how the bore 52 in the inventive flow control 12 reduces or even eliminates noise, the following theory explanation of how the bore 52 functions.
In conventional flow controls, air is distilled or otherwise removed from the liquid passing through the flow control washer. This and/or other factors generate noise, possibly by 1) cavitation in the low pressure region of the flow control downstream of the flow control washer and/or 2, vibration of the flow control washer at its resonant frequency. These noises can be carried and amplified throughout a building that includes the device having the flow control. It is believed that the introduction of air into the flow control 12 detunes the rubber of the flow control washer 30 . The detuning is believed to change the natural frequency of the flow control washer 30 sufficiently to avoid resonance. It is also believed that, in the inventive flow control 12 , the bore 52 negates a low pressure created by the accelerated liquid. That is, the flow of air into the liquid stream raises the minimum pressure in the system to a level that prevents cavitation.
The desired upper diameter of the bore 52 is limited by the production of noise from the air induction itself, while the desired lower diameter of the bore 52 is limited by the ability of the flow control 12 to draw enough ambient air into the flow control 12 to achieve the desired noise reduction effect in the tube 28 . When the discharged liquid is water and the tube 28 has a diameter on the order of 0.5″ to 2.0″, the bore diameter preferably is between 0.020″ and 0.060″, and preferably about 0.035″.
Flow controls constructed in accordance with the invention can accommodate a variety of volumetric flow rates. Depending on the sizing of the flow control flow rates of from about 0.5 gpm to about 25 gpm or even higher can be accommodated. They can also accommodate a wide range of supply pressures of, e.g., from less than 20 psig to more than 12.5 psig, for a typical application in which the liquid is discharged to the atmosphere at 14 psig.
3. Second Embodiment of the Flow Control
A second preferred embodiment of the flow control 112 is shown in FIGS. 2-3. The flow control 112 of the second preferred embodiment is similar to the flow control 12 of first preferred embodiment. Elements of the flow control 112 of FIGS. 2-3 corresponding to elements of the flow control 12 of FIG. 1 are incremented by 100. Flow control 112 therefore includes a tubular conduit 128 and a flow control washer 130 . The conduit 128 has an inlet 132 and an outlet 134 . A passageway 152 is formed in the conduit 128 downstream of the flow control washer 130 to admit gas into the conduit 128 for noise reduction purposes. However, the flow control 112 of this embodiment is significantly different from the embodiment of FIG. 1 in some respects.
For instance, the conduit 128 is configured to be mounted in series between two other conduits (not shown) and to facilitate mounting of the flow control washer 130 in the conduit 128 . The conduit 128 therefore is formed from a connector having female and male sections 154 , 156 secured to each other via a swage fitting 158 threaded onto the female section 154 and secured to male section 156 by locking ring 172 . The washer 130 is positioned between a downstream axial end 166 of the male section 156 and a shoulder 168 on the female section 154 . The female section 154 is sealed to the male section 156 by an O-ring 170 disposed radially between the sections 154 , 156 in the vicinity of the swage fitting 158 .
In addition, the interior of the female fitting 160 is shaped to enhance the venturi effect of liquid flow though the flow control 112 in order to enhance airflow into the flow conduit 128 and the resultant noise reduction. Specifically, a venturi 174 is formed in the conduit 128 downstream of the washer 130 . The venturi 174 includes a conically tapered inlet 176 , a conically tapered outlet 178 , and a relatively narrow throat 180 disposed between the inlet 176 and the outlet 178 . The bore 152 opens into the interior of the conduit 128 at the throat 180 of the venturi 174 , where the pressure drop of fluid flowing through the flow control 112 is a maximum.
A one-way valve 182 is also provided in this embodiment to prevent liquid from back flowing out of the bore 152 . Suitable valves include, but are not limited to, check valves, flapper valve, and duck-billed valves. The illustrated valve 182 is a duck-billed valve disposed in a boss 184 containing an outer end portion of the bore 152 . The valve 182 is formed from a rubber or other elastomeric material that is slit down its middle. The rubber halves of the valve 182 move apart to admit air into the bore 152 , but close to prevent the egress of liquid from the bore 152 .
In use, a liquid such as water enters the inlet 132 of the conduit 128 as represented by the arrow 148 in FIG. 3, flows through a central orifice 144 in the flow control washer 130 , flows through the venturi 174 , and exits the outlet 134 of the conduit 128 . Supply pressure fluctuations are accommodated by expansion and constriction of the orifice 144 to maintain a substantially constant volumetric flow rate through the flow control washer 130 and downstream components of the flow control 112 . The pressure drop created by liquid flow through the washer 130 and augmented by the venturi 174 draws a gas such as ambient air through the bore 152 and into the throat 180 of the venturi 174 as represented by the arrow 153 , thereby attenuating noises that otherwise would be generated by operation of the flow control 112 . The rubber halves of the duckbill valve 182 move apart to admit air into the bore 152 during this process, but close to prevent the egress of liquid form the bore 152 .
4. Third Embodiment of the Flow Control
A third preferred embodiment of the flow control 212 , which is illustrated in FIGS. 4-6, differs from the second preferred embodiment in that the venturi 274 is configured for installation in a separate fitting rather than being formed integrally with a fitting. Elements of the flow control 212 of FIGS. 4-6 corresponding to elements of the flow control 112 of FIGS. 2 and 3 are incremented by 100. The flow control 212 therefore includes a conduit 228 incorporating an integral venturi 274 and a flow control washer 230 mounted in the conduit 228 and having a central orifice 244 .
The flow control 212 of this embodiment is configured to minimize redesign of a flow control used in a drain fitting of a water softener control valve such as the valve 186 illustrated in FIG. 7 . The water softener control valve 186 includes a brine port 188 connected to a brine tank 190 , a service port 192 connected to a resin tank 194 containing a treatment medium, an inlet port 196 connected to an untreated water inlet line 198 , an outlet port 300 connected to a treated water outlet line 302 , and a wastewater discharge port 304 opening into a wastewater discharge fitting 306 connected to a drain line 308 . The flow control 212 is disposed in the wastewater discharge fitting 306 .
Referring back to FIGS. 4-6, the discharge fitting 306 comprises an elbow 216 incorporating the flow control 212 . The elbow 216 includes 1) a vertical upstream leg 226 configured for mounting in the wastewater discharge port 304 (FIG. 7) and 2) a horizontal downstream leg 308 configured for threaded connection to the drain line 308 (FIG. 7 ). The flow control 212 is formed in an insert 310 that is installed into the vertical leg 226 of the fitting 216 from the inner end. An outer peripheral surface of the insert 310 is sealed to an inner peripheral surface of the vertical leg 226 by a pair of spaced O-rings 316 , 317 . Sliding movement of the insert 310 due to pressure differential from operation of the flow control into the vertical leg 226 of the fitting 216 is limited by engagement of an annular ring 314 on the insert 310 with the upstream end of the fitting 216 . The fitting is otherwise held in place by friction from O-rings 314 and 316 . A boss 315 extends upstream from the ring 314 and is configured to extend into the discharge port 304 of the water softener control valve 186 . The flow control washer 230 is also positioned loosely within the boss 315 adjacent the ring 314 .
The venturi 274 includes a conically tapered inlet 276 , a conically tapered outlet 278 , and a relatively narrow throat 280 disposed therebetween. An air inlet passage connects the ambient atmosphere to a low pressure region of the venturi 274 to permit air to flow into the low pressure region as represented by the arrow 253 . In the illustrated embodiment, the passage is formed from a bore 251 through a boss 284 on the fitting 216 , through an annular space 208 formed between the outer peripheral surface of the insert 310 and the inner peripheral surface of the fitting 216 , and through a bore 252 opening into the outlet portion 278 of the venturi 274 near the throat 280 . As with the embodiment of FIGS. 2 and 3, the venturi 274 augments the venturi effect caused by the flow of liquid through the flow control washer 230 to maximize the noise reduction effects of airflow into the flow control 212 . Finally, and also as in the second embodiment, a duck-billed one-way valve 282 is mounted in the boss 284 to prevent water from flowing out of the flow control 212 via the air inlet passage.
5. Noise Reduction
The data shown in the Tables 1-4 below demonstrate the difference in noise reduction using a relatively small (0.5″ diameter) elbow for fitting in a water softener drain port fitting constructed in accordance with the third embodiment of the invention. Data are shown as “A weighted,” which is used for scientific purposes, and “C weighted,” which approximates the human ear. The fitting was connected to the water softener control valve 185 and to the drain line 203 with flexible tubes to isolate the flow control 212 from external noise sources. Noise levels were tested at various flow rates in gallons per minute (GPM). Noise was measured with air introduced via the bore 252 of the flow control (WITH AIR) and without air introduced (W/O AIR). The difference between the two noise measurements is shown in the column labeled “DIFF.”
TABLE 1
NOISE TEST WS1 CONTROL VALVE (inlet pressure 70 PSI)
BACKGROUND NOISE WAS 53 (37) dB AT
18″ TEST C (A) WEIGHTED
18 INCHES TO THE LEFT SIDE OF VALVE @ 57″ HIGH
C WEIGHTED
A WEIGHTED
WITH
WITH
GPM
AIR
W/O AIR
DIFF.
AIR
W/O AIR
DIFF.
0.7
72.0
78.5
6.5
77.0
80.9
3.9
1.0
69.5
80.0
10.5
68.6
82.5
13.9
1.3
74.0
81.5
7.5
72.3
80.5
8.2
1.7
70.8
80.0
9.2
68.2
80.5
12.3
2.2
70.5
80.0
9.5
73.4
82.0
8.6
2.7
68.0
78.0
10.0
68.5
80.2
11.7
3.2
68.5
79.3
10.8
69.5
81.0
11.5
4.2
69.0
78.5
9.5
70.8
81.0
10.2
5.3
71.0
78.0
7.0
72.0
79.5
7.5
TABLE 2
NOISE TEST WS1 CONTROL VALVE (inlet pressure 70 PSI)
BACKGROUND NOISE WAS 52 (35) dB AT THE 36″ POSITION C
(A) WEIGHTED
36 INCHES IN FRONT OF VAVLE @ 57″ HIGH
C WEIGHTED
A WEIGHTED
WITH
WITH
GPM
AIR
W/O AIR
DIFF.
AIR
W/O AIR
DIFF.
0.7
69.0
74.0
5.0
72.1
75.9
3.8
1.0
68.0
75.0
7.0
67.9
76.8
8.9
1.3
71.5
76.0
4.5
72.0
76.3
4.3
1.7
67.0
75.5
8.5
64.8
74.5
9.7
2.2
67.0
75.0
8.0
71.5
75.5
4.0
2.7
66.0
73.0
7.0
67.3
74.5
7.2
3.2
67.0
74.0
7.0
67.0
75.0
8.0
4.2
68.0
73.0
5.0
68.0
74.2
6.2
5.3
69.0
72.5
3.5
69.5
73.7
4.2
TABLE 3
NOISE TEST WS1 CONTROL VALVE (inlet pressure 70 PSI)
BACKGROUND NOISE WAS 53 (37) Db AT
18″ TEST C (A) WEIGHTED
18 INCHES TO THE LEFT SIDE OF VALVE @ 57 HIGH
C WEIGHTED
A WEIGHTED
WITH
WITH
GPM
AIR
W/O AIR
DIFF.
AIR
W/O AIR
DIFF.
0.7
62.2
66.0
3.8
62.3
68.5
6.2
1.0
58.0
67.8
9.8
58.0
70.0
12.0
1.3
59.8
69.1
9.3
60.5
70.7
10.2
1.7
69.0
75.8
6.8
71.5
77.0
5.5
2.2
60.0
74.0
14.0
61.6
75.1
13.5
2.7
61.5
72.2
10.7
61.7
74.2
12.5
3.2
62.8
72.5
9.7
62.1
73.8
11.7
4.2
64.2
72.0
7.8
65.0
74.0
9.0
5.3
66.2
72.2
6.0
67.5
75.0
7.5
TABLE 4
NOISE TEST WS1 CONTROL VALVE (inlet pressure 70 PSI)
BACKGROUND NOISE WAS 52 (35) dB
AT THE 36″ POSITION C (A) WEIGHTED
36 INCHES IN FRONT OF VAVLE @ 57″ HIGH
C WEIGHTED
A WEIGHTED
WITH
WITH
GPM
AIR
W/O AIR
DIFF.
AIR
W/O AIR
DIFF.
0.7
60.0
62.4
2.4
61.8
63.4
1.6
1.0
57.0
64.0
7.0
58.1
65.5
7.4
1.3
63.7
68.7
5.0
64.7
71.6
6.9
1.7
67.0
70.6
3.6
68.5
72.0
3.5
2.2
59.3
67.6
8.3
59.4
68.4
9.0
2.7
59.8
66.3
6.5
59.8
67.8
8.0
3.2
60.3
67.2
6.9
61.0
68.0
7.0
4.2
61.8
67.0
5.2
62.0
68.3
6.3
5.3
63.2
66.5
3.3
64.1
67.5
3.4
As can be seen from the data of Tables 1-4, introducing air via the air inlet passage of the flow control 212 significantly reduces noise levels under all conditions tested.
It is understood that the various preferred embodiments are shown and described above to illustrate different possible features of the invention and the varying ways in which these features may be combined. Apart from combining the different features of the above embodiments in varying ways, other modifications are also considered to be within the scope of the invention.
The invention is not intended to be limited to the preferred embodiments described above, but rather is intended to be limited only by the claims set out below. Thus, the invention encompasses all alternate embodiments that fall literally or equivalently within the scope of these claims. | A flow control includes a conduit and a flow control washer disposed in the conduit between the conduit's inlet and the outlet. A gas inlet passage opens into the conduit, preferably at a location just downstream of the flow control washer, to permit a gas (typically ambient air) to enter a liquid stream flowing through the flow control washer. The admission of a gas into this liquid stream reduces noise generated by liquid flow through the flow control washer. Gas induction and noise reduction capabilities may be enhanced by admitting the gas fluid into a low pressure region of a venturi located in the conduit downstream of the flow control washer. The flow control is particularly useful in a wastewater drain of a water softener control valve, but is also useful in a variety of other applications. A method of reducing noise in a flow control is also provided. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/116,774, filed Apr. 28, 2005, which is a continuation of U.S. patent application Ser. No. 10/414,134 filed Apr. 14, 2003, which issued as U.S. Pat. No. 6,889,680 on May 10, 2005, which in turn claimed priority to U.S. Provisional Patent Application No. 60/372,273 filed Apr. 12, 2002, which are incorporated by reference as if fully set forth.
FIELD OF INVENTION
This invention relates to paintball loaders and, more particularly, to a detection system for controlling ball feed in a paintball loader.
BACKGROUND
Popularity and developments in the paintball industry have led to the demand for increased performance from paintball guns. Paintball gun users usually partake in paintball war games. A paintball war game is generally played between two teams of players that try to capture the opposing team's flag. Each flag is located at the team's home base. Such a game is played on a large field with opposing home bases at each end. The players are each armed with a paintball gun that shoots paintballs. Paintballs are gelatin-covered spherical capsules filled with paint.
During the game, the players of each team advance toward the opposing team's base in an to attempt to steal the opposing team's flag. The players must do so without first being eliminated from the game by being hit by a paintball shot by an opponent's gun. When a player is hit by a paintball the gelatin capsule ruptures and the paint is splashed onto the player. As a result the player is “marked” and is out of the game.
These war games have increased in popularity and sophistication resulting in more elaborate equipment. One such improvement is the use of semi-automatic and automatic paintball guns which allow for rapid firing of paintballs. As a result of the increased firing speed, a need has developed for increased storage capacity of paintballs in the paintball loaders that are mounted to the gun. Also, users demand faster feed rates as the guns continue to develop.
Paintball loaders typically include a housing that sits on an upper portion of a paintball gun and which is designed to hold a large quantity of paintballs. There is an outlet tube at the bottom of the housing through which the paintballs drop by the force of gravity. The paintballs pass into an inlet tube located in the upper portion of the gun.
In use, paintballs fall sequentially through the outlet tube into the inlet of the gun. The inlet tube directs each paintball into the firing chamber of the gun where the paintball is propelled outwardly from the gun by compressed air. Because existing paintball loaders rely on the force of gravity to feed the paintballs to the gun, they function properly to supply paintballs only if the gun and the loader are held in a substantially upright position. If, during a game, a player is forced to hold the gun sideways or upside down, the loader will not function properly.
Furthermore, it is not uncommon that, while feeding paintballs to the gun, the paintballs jam in the gun. In order to correct the problem, the player may shake the gun or strike the loader in order to dislodge the jammed paintball. This obviously places the player at risk during the game since the player is distracted by the need to adjust the equipment.
Currently there are on the market paintball loaders that utilize an optical sensor mounted within the loaders to detect the absence of a paintball in the infeed tube of a paintball gun. When the sensor detects that there is no paintball in the infeed tube of the paintball gun, a motor is activated which causes a paddle to force a paintball into the paintball gun. Other conventional paintball loaders utilize agitators having sound sensors to sense a gun firing event. In response to the sound of the gun firing, an electrical signal is sent to activate an agitator which moves a paintball into the feed tube.
While recent feed systems are an improvement over the prior feeders, the current feed systems are complicated and costly to manufacture. Such systems may also lead to jamming.
There is, therefore, a need for a feed mechanism for a feed system that simply and reliably feeds paintballs to a paintball gun at a high rate, while at the same time prevents or reduces the likelihood of paintball jams. There is also a need for a paintball loader which controls the feed motor so as to prolong battery life and reduce undesirable noise.
SUMMARY
In one aspect, the present invention is a ball feed mechanism for use in a paintball loader. The ball feed mechanism includes a feeder for feeding paintballs. The feeder may be a drive cone, paddle wheel, or indexing belt, which has protrusions, recesses or paddles that convey or impel balls toward a feed neck. The feed mechanism also preferably includes a drive shaft which is concentric with the feeder. The feeder mounts on the drive shaft and is free to rotate about the drive shaft before engaging mechanical stops. The feeder is coupled to the drive shaft through a spring. The spring is configured to store potential energy which is used to rotate the feeder and, thus, drive the balls toward the feed neck. An electric motor is used to rotate the drive shaft to wind or compress the spring.
In operation the spring is normally compressed so that the spring energy is always available to impel balls toward the feed neck as required. The motor is energized as needed to restore the spring energy (e.g., through compression of the spring). Other resilient members, such as elastomers, may be used in place of the spring.
The feed mechanism includes an indexing mechanism which includes a sensor, for example, to determine the degree of tension or winding of the spring. In one embodiment, the indexing mechanism accomplishes this by using the sensors to detect rotational movement of the feeder and a drive mechanism (which includes the drive shaft). A controller is in communication with the sensors and determines the relative position of the feed mechanism to the drive mechanism for determining whether the spring requires winding. The relative position of the feeder and drive mechanism can be correlated with the degree of compression/tension of the spring. If the controller determines that the spring requires winding, a motor is activated, causing the drive mechanism to rotate. This, in turn, causes the spring to wind.
The feed mechanism may alternately include a tensionometer or a strain gauge in communication with a controller. These devices are used to determine the state of deflection of the spring. If the controller determines that additional deflection of the spring is required, the controller will actuate a motor which rotates the drive mechanism and the spindle. The rotation of the spindle, in turn, causes the spring to compress or tension.
The foregoing and other features of the invention and advantages of the present invention will become more apparent in light of the following detailed description of the preferred embodiments, as illustrated in the accompanying figures. As will be realized, the invention is capable of modifications in various respects, all without departing from the invention. Accordingly, the drawings and the description are to be regarded as illustrative in nature, and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing summary, as well as the following detailed description of the invention, will be better understood when read in conjunction with the appended drawings. In the drawings:
FIG. 1 is a side elevation view of a rapid feed paintball loader constructed in accordance with the teachings of the present invention and operatively attached to a representative paintball gun illustrated in phantom;
FIG. 2 is an exploded upper isometric view of one embodiment of the loader according to the present invention;
FIG. 3 is an exploded lower isometric view of the embodiment of the loader shown in FIG. 2 ;
FIG. 4 is a lower isometric view of the embodiment of the loader shown in FIG. 3 ;
FIG. 5 is an exploded upper isometric view of a second embodiment of the loader according to the present invention;
FIG. 6 is a side view of the loader of FIG. 5 ;
FIG. 7 is a top view of an alternate feeder according to the present invention;
FIG. 8 is a top view of yet another feeder according to the present invention;
FIG. 9 is a schematic of a controller according to the present invention; and
FIG. 10 illustrates a pulley mechanism for driving the drive shaft in accordance with an alternate embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings wherein like numerals indicate like elements throughout, FIG. 1 is a side elevation view of paintball loader 40 in accordance with the present invention and operatively attached to a representative paintball gun 20 , illustrated in phantom. The paintball gun 20 , includes a main body 22 , a compressed gas cylinder 24 , a front handgrip 26 , a barrel 28 , and a rear handgrip 30 . The paintball gun 20 also includes an inlet tube 32 , leading to a firing chamber (not shown) in the interior of the main body and a trigger 34 . The front handgrip 26 preferably extends downwardly from the barrel 28 and provides a grip. The compressed gas cylinder 24 is typically secured to a rear portion of the paintball gun 20 . The compressed gas cylinder normally contains CO2, NO2 or air, although other gases may also be used.
In using the paintball gun 20 , trigger 34 is squeezed, thereby actuating the compressed gas cylinder to release controlled bursts of compressed gas. The bursts of gas are used to eject paintballs outwardly through the barrel 28 . The paintballs are continually fed by the paintball loader 40 through the inlet tube of the firing chamber. The paintball gun depicted in FIG. 1 is an automatic paintball gun, however the gun may also be semi-automatic.
The paintball loader 40 comprises a paintball container 42 having a container wall 44 forming an interior area 46 . The container has an upper portion 48 and a lower portion 50 . An exit tube 52 leads from the lower portion of the container to an outlet opening 54 . The exit tube is positioned on top of the inlet tube 32 of the paintball gun 20 . A feed mechanism 100 (shown in FIG. 2 ) is used to drive or urge the paintballs toward the exit tube and into the inlet tube 32 .
FIG. 2 is an exploded isometric view of one embodiment of the feed mechanism 100 according to the present invention. While a preferred feed mechanism 100 is shown, various other components may be substituted therefore for driving paintballs into the paintball gun 20 . The feed mechanism 100 includes a feeder 102 which drives or otherwise conveys paintballs into the exit tube 52 , and a drive mechanism 500 .
A variety of feeders 102 can be used in the present invention, including an feeder, drive cone, paddle wheel, carrier or other device which can direct or otherwise urge paintballs from the loader into the exit tube 52 . One preferred feeder 102 is shown in the figures and includes a housing 103 with a plurality of fins 104 which preferably extend in a radial direction from the housing 103 . While the fins 104 are shown as being straight, other shapes can be used as will be discussed below. The feeder 102 also preferably includes flanges 105 that extend between adjacent fins 104 . As should be apparent from the drawings, the housing, fins and flanges can be made as a single injection molded part. While fins are shown, the feeder may include recesses within which the paintballs sit as they are shuttled toward the exit tube.
A cylindrical opening 106 is formed in the center of the housing 103 for receiving a fastener 130 . The fastener 130 is used to engage or mount the feeder 102 to a drive shaft or spindle 108 of the drive mechanism 500 . More particularly, the fastener 130 extends through the opening 106 and threads into a hole formed in the top of the drive shaft 108 .
Referring now to FIG. 3 , the bottom of the feeder 102 is shown in more detail. The housing 103 includes a first flange 124 which is attached to and projects downward from the housing 103 . In the illustrated embodiment, the first flange 124 is formed integral with the housing 103 . The first flange 124 is designed to engage with a first end of a spring 116 as will be better understood hereafter.
As shown in FIGS. 2-4 , the drive mechanism 500 includes a spring housing 112 which is disposed about the drive shaft 108 and is positioned so as to be below the feeder 102 . The spring housing 112 includes an outer wall 113 and a bottom wall 115 . An inner wall 117 is formed about a central opening 119 . The drive shaft 108 is designed to pass through the central opening 119 and engage with the spring housing 112 such that rotation of the drive shaft 108 produces concomitant rotation of the spring housing 112 . In the illustrated embodiment, a portion of the drive shaft 108 is shown non-cylindrical in shape and the opening 119 is formed with a mating non-cylindrical shape. A spring clip 132 or similar fastener is preferably used to restrain vertical movement of the spring housing 112 on the drive shaft 108 . This is more clearly illustrated in FIG. 4 which shows the spring housing 112 mounted to the drive shaft 108 .
A second flange 120 is attached to or, more preferably, formed integral with the spring housing 112 . The second flange 120 is configured to engage with a send end of the spring 116 .
The inner wall 117 and outer wall 113 define a spring chamber 114 within the spring housing 112 . A spring or other biasing member 116 is located within the spring chamber 114 . Although a spring is shown in the figures, it should be readily apparent that other biasing members, such as elastomers, could instead be used. The spring 116 is preferably a torsion spring. A first leg 150 on the first end of the spring 116 is adapted to engage with the first flange 124 on the feeder 102 . A second leg 152 on the second end of the spring is adapted to engage with the second flange 120 on the spring housing 112 . As such, the spring 116 is mounted so as to bias the feeder 102 against rotation relative to the spring housing 112 . In other words, rotation of the spring housing 112 relative to the feeder 102 produces deflection or winding of the spring 116 . When the spring is rotated in the direction which produces winding of the spring, the rotation creates a restoring force (potential energy) in the spring which attempts to counter-rotate the spring housing 112 relative to the feeder 102 . As should be readily apparent, if the feeder 102 is unrestrained, rotation of the spring housing will produce concomitant rotation of the feeder 102 . It is only when there is something which inhibits rotation of the feeder 102 (such as paint balls already in the exit tube) that the spring housing 112 will wind the spring 116 .
FIG. 4 illustrates the assembled feeder 102 , spring housing 112 , and the drive shaft 108 . The drive shaft 108 projects downward from the spring housing 112 and is adapted to engage with a drive member or gear that is part of the drive mechanism 500 .
Extending downward from the lower surface of the feeder 102 is at least one and, more preferably, a plurality of spaced apart upper indexing teeth 160 . The upper indexing teeth 160 are preferably spaced in a circular pattern about the bottom of the feeder 102 . As will be discussed below, the upper indexing teeth 160 are used in combination with a sensor to determine the rotational position of the feeder 102 . The indexing teeth 160 are preferably formed integral with or attached to the feeder 102 . While indexing teeth are shown in the illustrated embodiment, other indexing members, such as reflectors, markers, recesses, etc, may be used.
Referring back to FIGS. 2 and 3 , one embodiment of the drive member 508 is shown. In this embodiment, the drive member 508 is a drive gear includes a plurality of spaced apart gear teeth 503 formed about the periphery of the drive gear 508 . The teeth 503 of the drive gear 508 are adapted to engage with mating teeth on a second gear connected to a motor 95 . While the drive member 508 in the illustrated embodiment is a gear, other types of conventional drive members can be used to produce controlled rotation, such as a pulley mechanism or stepper motor. A pulley mechanism is shown in FIG. 10 . The pulley 508 is engaged to the motor through a belt 97 .
The drive member 508 also includes at least one and, more preferably, a plurality of lower indexing members 510 formed on the drive gear 508 and preferably on its lower surface. As with the upper indexing teeth 160 , the lower indexing members 510 are used to determine the position of the drive gear 508 and, thus, the spring housing 112 . While the indexing members are shown as protrusions in the illustrated embodiment, other indexing members, such as teeth, reflectors, markers, recesses, etc, may be used.
The feed mechanism 100 also includes a first indexing sensor positioned below and preferably adjacent to the lower surface of the feeder 102 . The first indexing sensor 504 is located so as to be able to detect or otherwise sense the upper indexing teeth 160 . More particularly, as the feeder 102 rotates around its central axis, the sensor 504 detects the upper indexing teeth 160 as they pass the sensor. The number of passing teeth 160 that is sensed (e.g., over a prescribed period) is used to determine the rotational motion of the feeder 102 . As should be readily apparent, the more upper indexing teeth 160 that are formed on the feeder 102 , the more accurate the position of the feeder 102 can be determined. A signal is sent from the sensor indicative of the sensed number of passing teeth. Alternatively, the sensor 504 may be a ratcheting mechanism that supplies the controller with a signal after the ratchet has rotated a predetermined number of times or amount.
A second indexing sensor 506 is mounted adjacent to the drive gear 508 so as to be able to detect the passing of the lower indexing members 510 . The rotational motion of the drive gear 508 and, thus, the spring housing 112 , is determined by counting the number of passing lower indexing members 510 . A signal is sent from the sensor indicative of the sensed number of passing teeth. While the illustrated embodiment depicts the sensor and indexing members as being mounted to the drive gear, it should be readily understood that the sensor can be mounted so as to detect rotational motion of the drive shaft.
Referring to FIG. 9 , the first indexing sensor 504 and second indexing sensor 506 are in communication with a controller 900 , such as a computer or microprocessor (not shown). The controller 900 determines the position of the feeder 102 relative to the drive gear 508 and evaluates whether the spring 116 requires tensioning (winding) or deflection. If the controller 900 determines that the spring 116 requires tensioning, the controller will actuate a motor 950 which is engaged with the drive gear 508 to rotate the drive gear 508 a desired amount. The engagement is preferably through a drive system 960 , such as a gear that meshes with the teeth 503 on the drive gear 508 . Rotation of the drive gear 508 , in turn, rotates the drive shaft 108 and, thus, the spring housing 112 . The rotation of the spring housing 112 relative to the feeder 102 causes the spring 116 to wind, preferably until the second flange 120 meets the first flange 124 .
During operation, as the feeder 102 advances the paint balls into the gun, the first sensor 504 counts the number of upper indexing teeth 160 that have passed and provides a signal to the controller. The second sensor 506 , likewise, counts the number of lower indexing members 510 that have passed and provides a signal indicative thereof to the controller. It is envisioned that, during firing, the drive gear 508 may not necessarily be moving. Instead, only after the controller 900 detects that the positional location of the feeder 102 relative to the drive gear 508 correlates to a spring that needs “rewinding” would the controller 900 send a signal to the motor 950 to rotate the drive gear 508 . For example, the system may be set such that only after half of the paintballs are dispensed that can be held by the feeder is the motor activated to rotate the drive gear 508 .
Alternately, the controller 900 can continuously monitor the movement of the feeder 102 and the drive gear 508 . Any movement of the feeder 102 relative to the drive gear 508 can result in the motor rotating the drive gear 508 to rewind the spring. Thus, the gun will always be set to feed the maximum number of balls possible using the feeder.
The controller 900 may also be programmed to rotate the drive gear 508 a prescribed distance to wind the spring, thus preventing overwinding. The lower indexing members 510 can be tracked through the second sensor 506 to stop the rotation of the drive gear 508 when desired. For example, the controller may be programmed to tension the spring a sufficient amount to feed 10 paintballs into the gun before needing to be rewound. Upon firing of the gun, tension of the spring will feed the 10 paintballs into the exit tube. The controller determines the number of balls to be fed from the data provided by the first indexing sensor 504 .
Alternatively, the present invention may utilize only one sensor to detect the movement of the feeder. A motor, such as a stepper motor, can be used to incrementally wind the spring for every detected movement of the feeder. For example, if the spring has a tension sufficient to feed 10 paintballs, for every ball that the sensor detects as being fed by the feeder, the motor will wind the spring by 1/10th of the complete rotation.
The controller may be used to detect whether there are any paintballs in the exit tube. If the controller 900 determines that there are no paintballs in the tube, that would indicate that the spring is in an unwound condition. Thus, the controller 900 would activate the motor 950 and rewind the spring.
An alternate embodiment of the sensor mechanism is shown in FIG. 5 . In this embodiment, the first sensor includes a first emitter 602 and a first receiver 604 . The first emitter 602 provides a beam that is reflected by reflectors placed around the periphery of the underside of feed cone 102 . The reflected signal is detected by receiver 604 . Although depicted separately for clarity, the emitter 602 and receiver 604 may be housed in the same unit. The beam may be an infrared (IR) beam. Likewise a second emitter 606 and a second receiver 608 are provided in lieu of second indexing sensor 506 . The second emitter 606 provides a beam that is reflected by reflectors placed around the periphery of the top or underside of drive gear 508 . The reflected beam is detected by second receiver 608 . The emitter 606 and receiver 608 may be housed in the same unit, or mounted separate as shown. The first and second emitters/receivers are in communication with the controller 900 . FIG. 6 illustrates the assembled unit of FIG. 5 .
The sensing mechanism may instead include a tensionometer or strain gauge 93 (shown in phantom in FIG. 2 ) to determine the tension of the spring. The strain gauge would be in communication with the controller. If the tension in the spring falls below a preselected limit, the controller will actuate the motor which rotates the drive mechanism that in turn rotates the spindle, thereby tensioning the spring.
Referring to FIGS. 7 and 8 , alternate feeder arrangements are shown. More particularly, FIG. 7 illustrates a feeder 200 which includes two fins 202 . The fins are spaced 180 degrees apart, thus permitting a plurality of balls 206 to be located between adjacent fins 202 . FIG. 8 illustrates a feeder with a plurality of curved fins 302 , each one designed to cup an individual paintball 206 . Those skilled in the art would be readily capable of substituting alternate design configurations for the feeder in order to effect sufficient feeding of the desired number of paint balls.
The present invention provides a novel system for feeding paintballs from a container. The use of a two sensors permits controlled feeding which is not possible with conventional feeders. The controller in the present invention can be adjusted to minimize use of the motor, thereby conserving battery power. The controller can also be used to accurately track the amount of balls dispensed.
Furthermore, the controller in the present invention can also be controlled so as to vary the tension and pressure applied to the ball supply. The feed mechanism can include a user input mechanism, such as a dial or pushbuttons, which permits the user to adjust when the drive mechanism re-winds the spring.
While the potential energy caused by the spring has been described as resulting from winding the spring, it should be readily apparent that a compression spring can be used, in which case the winding of the spring should be understood to refer to a compression of the spring to build up a restoring force or potential energy.
The present invention may be embodied in other specific forms without departing from the spirit thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification, as indicating the scope of the invention.
Although preferred embodiments of the sensors have been described and shown in the drawings, those skilled in the art will understand how features from the two embodiments may be combined and interchanged. | The present invention is directed to a ball feed mechanism and associated method for use in a paintball loader. The ball feed mechanism includes a feeder which conveys or impels balls toward a feed neck, and a drive member which is concentric with the feeder. The feeder is coupled to the drive member. An electric motor is used to rotate the drive member which in turn causes the feeder to rotate. The feed mechanism includes sensors which detect the motion of the feeder and the drive member. A controller determines the position of the feeder relative to the drive member and actuates a motor when necessary. | 5 |
RELATED APPLICATION
The present application claims benefit of U.S. Provisional Application Ser. No. 60/069,405 filed Dec. 18, 1997.
FIELD OF THE INVENTION
The present invention relates to a method for preparing a lithographic printing plate using a heat mode imaging element comprising an IR sensitive top layer.
More specifically the invention is related to a method for preparing a lithographic printing plate using a heat mode imaging element whereby the capacity of the top layer of being penetrated and/or solubilised by an aqueous developer is changed upon exposure.
BACKGROUND OF THE INVENTION
Lithography is the process of printing from specially prepared surfaces, some areas of which are capable of accepting lithographic ink, whereas other areas, when moistened with water, will not accept the ink. The areas which accept ink form the printing image areas and the ink-rejecting areas form the background areas.
In the art of photolithography, a photographic material is made imagewise receptive to oily or greasy inks in the photo-exposed (negative-working) or in the non-exposed areas (positive-working) on a hydrophilic background.
In the production of common lithographic printing plates, also called surface litho plates or planographic printing plates, a support that has affinity to water or obtains such affinity by chemical treatment is coated with a thin layer of a photosensitive composition. Coatings for that purpose include light-sensitive polymer layers containing diazo compounds, dichromate-sensitized hydrophilic colloids and a large variety of synthetic photopolymers. Particularly diazo-sensitized systems are widely used.
Upon imagewise exposure of the light-sensitive layer the exposed image areas become insoluble and the unexposed areas remain soluble. The plate is then developed with a suitable liquid to remove the diazonium salt or diazo resin in the unexposed areas.
Alternatively, printing plates are known that include a photosensitive coating that upon image-wise exposure is rendered soluble at the exposed areas. Subsequent development then removes the exposed areas. A typical example of such photosensitive coating is a quinone-diazide based coating.
Typically, the above described photographic materials from which the printing plates are made are camera-exposed through a photographic film that contains the image that is to be reproduced in a lithographic printing process. Such method of working is cumbersome and labor intensive. However, on the other hand, the printing plates thus obtained are of superior lithographic quality.
Attempts have thus been made to eliminate the need for a photographic film in the above process and in particular to obtain a printing plate directly from computer data representing the image to be reproduced. However the photosensitive coating is not sensitive enough to be directly exposed with a laser. Therefor it has been proposed to coat a silver halide layer on top of the photosensitive coating. The silver halide can then directly be exposed by means of a laser under the control of a computer. Subsequently, the silver halide layer is developed leaving a silver image on top of the photosensitive coating. That silver image then serves as a mask in an overall exposure of the photosensitive coating. After the overall exposure the silver image is removed and the photosensitive coating is developed. Such method is disclosed in for example JP-A-60-61 752 but has the disadvantage that a complex development and associated developing liquids are needed.
GB-1 492 070 discloses a method wherein a metal layer or a layer containing carbon black is provided on a photosensitive coating. This metal layer is then ablated by means of a laser so that an image mask on the photosensitive layer is obtained. The photosensitive layer is then overall exposed by UV-light through the image mask. After removal of the image mask, the photosensitive layer is developed to obtain a printing plate. This method however still has the disadvantage that the image mask has to be removed prior to development of the photosensitive layer by a cumbersome processing.
Furthermore methods are known for making printing plates involving the use of imaging elements that are heat-sensitive rather than photosensitive. A particular disadvantage of photosensitive imaging elements such as described above for making a printing plate is that they have to be shielded from the light. Furthermore they have a problem of sensitivity in view of the storage stability and they show a lower resolution. The trend towards heat mode printing plate precursors is clearly seen on the market.
For example, Research Disclosure no. 33303 of January 1992 discloses a heat mode imaging element comprising on a support a cross-linked hydrophilic layer containing thermoplastic polymer particles and an infrared absorbing pigment such as e.g. carbon black. By image-wise exposure to an infrared laser, the thermoplastic polymer particles are image-wise coagulated thereby rendering the surface of the imaging element at these areas ink-acceptant without any further development. A disadvantage of this method is that the printing plate obtained is easily damaged since the non-printing areas may become ink accepting when some pressure is applied thereto. Moreover, under critical conditions, the lithographic performance of such a printing plate may be poor and accordingly such printing plate has little lithographic printing latitude.
U.S. Pat. No. 4,708,925 discloses imaging elements including a photosensitive composition comprising an alkali-soluble novolac resin and an onium-salt. This composition can optionally contain an IR-sensitizer. After image-wise exposing said imaging element to UV-visible--or IR-radiation followed by a development step with an aqueous alkali liquid there is obtained a positive or negative working printing plate. The printing results of a lithographic plate obtained by irradiating and developing said imaging element are poor.
EP-A-625 728 discloses an imaging element comprising a layer which is sensitive to UV- and IR-irradiation and which can be positive or negative working. This layer comprises a resole resin, a novolac resin, a latent Bronsted acid and an IR-absorbing substance. The printing results of a lithographic plate obtained by irradiating and developing said imaging element are poor.
U.S. Pat. No. 5,340,699 is almost identical with EP-A-625 728 but discloses the method for obtaining a negative working IR-laser recording imaging element. The IR-sensitive layer comprises a resole resin, a novolac resin, a latent Bronsted acid and an IR-absorbing substance. The printing results of a lithographic plate obtained by irradiating and developing said imaging element are poor.
Furthermore EP-A-678 380 discloses a method wherein a protective layer is provided on a grained metal support underlying a laser-ablatable surface layer. Upon image-wise exposure the surface layer is fully ablated as well as some parts of the protective layer. The printing plate is then treated with a cleaning solution to remove the residu of the protective layer and thereby exposing the hydrophilic surface layer.
EP-A-97 200 588.8 discloses a heat mode imaging element for making lithographic printing plates comprising on a lithographic base having a hydrophilic surface an intermediate layer comprising a polymer, soluble in an aqueous alkaline solution and a top layer that is sensitive to IR-radiation wherein said top layer upon exposure to IR-radiation has a decreased or increased capacity for being penetrated and/or solubilised by an aqueous alkaline solution.
Said heat-mode imaging element has the disadvantage that on the lithographic surface having a hydrophilic surface two layers have to be coated from a solvent, which is a cumbersome operation. Furtheron said heat-mode imaging element has the disadvantage that some ablation occurs during the irradiation causing formation of some debris. Said debris can interfere with the transmission of the laser beam (e.g. by depositing on a focusing lens or as an aerosol that partially blocks transmission) or with the transport of the imaging element during or after recording when this debris remains loosely adhered to the plate and deposition of said debris occurs on the transport rollers.
GB-A-1 245 924 discloses an information recording method wherein a recording material is used comprising a heat-sensitive recording layer of a composition such that the solubility of any given area of the layer in a given solvent can be increased by heating that area of the layer, wherein the said layer is information-wise heated to produce a record of the information in terms of a difference in the solubilities in the said solvent of different areas of the recording layer, and wherein the whole layer is then contacted with such solvent to cause the portions of the recording layer which are soluble or most soluble in such solvent to be removed or penetrated by such solvent.
EP-A-347 245 discloses a method for development-processing of presensitized plates for use in making lithographic printing plates which comprises imagewise exposing the presensitized plate to light and development-processing the exposed presensitized plate with an alkaline developer and a replenisher, wherein the developer and the replenisher are aqueous solutions of an alkali metal silicate and the ratio (SiO 2 ):(M 2 O) (wherein (SiO 2 ) and (M 2 O) are the molar concentrations of respectively SiO 2 and an alkali metal oxide M 2 O) of the replenisher ranges from 0.6 to 1.5.
U.S. Pat. No. 5,466,557 discloses a radiation-sensitive composition comprising (1) a resole resin, (2) a novolac resin, (3) a latent Bronsted acid, (4) an infrared absorber, and (5) terephthalaldehyde.
GB-A-1 155 035 discloses a method of recording information, wherein a recording material is used comprising a layer of a polymeric material which when any given area of the layer is sufficiently heated undergoes in that area a modification resulting in a decrease in the solubility of that area of the layer in water or an aqueous medium, such layer also incorporating a substance or substances distributed over the whole area of the layer and being capable of being heated by exposing the layer to intense radiant energy which is absorbed by such substance or substances, and wherein the said material is exposed to intense radiant energy which is distributed over the material in a pattern determined by the information to be recorded and which is at least partly absorbed by said distributed substance or substances, so that a corresponding heat pattern is generated in the material, whereby such information is recorded in terms of a difference in the solubilities in water or an aqueous medium of different areas of said layer.
GB-A-1 154 568 discloses a method of recording a graphic original having contrasting light-absorbing and light-transmitting areas, wherein a recording material comprising a supported layer composed mainly of gelatin the water-solubility or water-absorptive capacity of which increases if the layer is sufficiently heated such layer also having light absorbing substance(s) distributed therein, is placed with such gelatin layer in contact with the light-absorbing areas of the original and the said gelatin layer is exposed to light through the original, the intensity of the light and the duration of the exposure being such that the areas of the gelatin layer in contact with the light-absorbing areas of the original are substantially unaffected by heat conduction from such light-absorbing areas, but the water-solubility or water-absorptive capacity of the other areas of the gelatin layer is increased by heating thereof due to absorption of copying light by the light-absorbing substance(s) in those other areas of the gelatin layer.
So, there is a need for a heat-mode imaging element which is easy to prepare and which undergoes little or no ablation during the IR-radiation.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a method for making lithographic printing plates from heat mode imaging elements which are easy to prepare.
It is a further object of the invention to provide a method for making lithographic printing plates from a heat mode imaging element which undergoes little or no ablation during the IR-radiation.
It is an object of the invention to provide a method for making positive lithographic printing plates from a heat mode sensitive imaging element having excellent printing properties, developable in a selective, rapid convenient and ecological way.
It is further an object of the present invention to provide a method for making positive lithographic printing plates from a heat mode sensitive imaging element having a high infrared sensitivity.
It is also an object of the present invention to provide a method for making positive lithographic printing plates from a heat mode sensitive imaging element which can be imaged by laser exposure at short as well as at long pixel dwell times.
Further objects of the present invention will become clear from the description hereinafter.
SUMMARY OF THE INVENTION
According to the present invention there is provided a method for making lithographic printing plates including the following steps
a) preparing a heat mode imaging element consisting of a lithographic base with a hydrophilic surface and a top layer which top layer is sensitive to IR-radiation, comprises a polymer, soluble in an aqueous alkaline solution and is unpenetrable for an alkaline developer containing SiO 2 as silicates;
b) exposing imagewise said heat mode imaging element to IR-radiation;
c) developing said imagewise exposed heat mode imaging element with said alkaline developer so that the exposed areas of the top layer are dissolved and the unexposed areas of the top layer remain undissolved characterized in that said top layer includes an IR-dye selected from the group consisting of indoaniline dyes, cyanine dyes, merocyanine dyes, oxonol dyes, porphine derivatives, anthraquinone dyes, merostyryl dyes, pyrylium compounds, diphenyl and triphenyl azo compounds and squarylium derivatives.
DETAILED DESCRIPTION OF THE INVENTION
It has been found that a heat-sensitive imaging element according to the invention can he obtained in an easy way by one coating, which yields a lithographic printing plate of high quality with little or no ablation in an ecologically acceptable way.
The IR-sensitive layer, in accordance with the present invention comprises an IR-dye and a polymer, soluble in an aqueous alkaline solution. A mixture of IR-dyes may be used, but it is preferred to use only one IR-dye. Suitable IR-dyes are known since a long time and belong to several different chemical classes, e.g. indoaniline dyes, oxonol dyes, porphine derivatives, anthraquinone dyes, merostyryl dyes, pyrylium compounds and sqarylium derivatives Preferably said IR-dyes, especially for irradiation with a laser source with an emission spectrum of about 1060 nm belongs to the scope of the general formula of the German patent application DE-4. 31 162. This general formula (I) is represented by: ##STR1## wherein K represents Q together with a counterion An--, or ##STR2## wherein Q represents chlorine, fluorine, bromine, iodine, alkyloxy, aryloxy, dialkylamino, diarylamino, alkylarylamino, nitro, cyano, alkylsulphonyl, arylsulphonyl, heterocyclyl, or a moiety represented by L--S--,
wherein
L represents alkyl, aryl, heterocyclyl, cyano or substituted carbonyl, thiocarbonyl or iminocarbonyl,
An-- represents an anion commonly used in the chemistry of cationic dyes, or an equivalent thereof,
B 1 represents cyano, alkoxycarbonyl, alkyl- or arylcarbonyl, or aminocarbonyl optionally substituted once or twice at the nitrogen atom by alkyl and/or aryl,
B 2 represents arylsulphonyl, alkylsulphonyl, heteroaryl, or, ##STR3## can be represented by ##STR4## wherein B 3 represents the non-metal atoms to complete a carbocyclic or heterocyclic ring,
ring T can be substituted by 1 to 3 C 1 -C 4 alkyl groups, n=1 or 2, and
A 1 and A 2 can represent following combinations:
(1) moieties of formulas (IIIa) and (IIIb): ##STR5## wherein X 3 , X 10 =0,
X 4 , X 11 =--CR 38 =--CR 39 ,
R 38 and R 39 each independently represent hydrogen, alkyl, aryl or together the necessary non-metal atoms to complete a cycloaliphatic, aromatic or heterocyclic 5- or 7-membered ring, or independently from each other, the necessary non-metal atoms to complete a cycloaliphatic, aromatic or heterocyclic 5- or 7-membered ring, and
R 3 , R 4 1 , R 19 and R 20 each independently represent hydrogen, C 1 -C 8 alkyl, aryl, halogen, cyano, alkoxycarbonyl, optionally substituted aminocarbonyl, amino, monoalkylamino, dialkylamino, hydroxy, alkoxy, aryloxy, alkylthio, arylthio, acyloxy, acylamino, arylamino, alkylcarbonyl, arylcarbonyl, or the necessary non-metal atoms to complete a cycloaliphatic, aromatic or heterocyclic 5- or 7-membered ring,
R 47 and R 50 each independently represent hydrogen, alkyl, aryl, cyano, alkoxycyano or the non-metal atoms to form a saturated or unsaturated 5- to 7-membered ring, in the first case between R 47 and resp. X 4 and R 3 , in the second case between R 50 and resp. X 11 and R 19 .
(2) moieties of the same formulas (IIIa) and (IIIb)
wherein
X 3 , X 10 =R 44 N,
X 4 , X 11 =--CR 38 =--CR 39 , and
wherein
R 3 and R 4 , respectively R 38 and R 39 together represent the atoms to complete an optionally substituted aromatic ring, and
wherein
R 44 represents optionally substituted alkyl or aryl, or the necessary atoms to complete a 5- or 7- membered ring,
(3) moieties of the formulas (IVa) and (IVb): ##STR6## wherein X 5 and X 12 each independently represent O, S, Se, Te or R 44 N,
R 5 to R 10 and R 21 to R 26 each independently represent one of the meanings given above for R 3 , and
R 48 and R 51 each independently represent hydrogen, alkyl, aryl or alkoxycarbonyl,
with the exception for those compounds in which together X 5 , X 12 =R 44 N and Q=halogen,
(4) moieties of formulas (VIIa) and (VIIb) ##STR7## wherein R 60 and R 61 each independently represent hydrogen, alkyl, aryl, cyano, alkoxycarbonyl, halogen,
R 62 , R 64 , R 66 1 , R 68 each independently represent alkyl or aryl,
R 63 1 , R 65 , R 67 , R 69 each independently represent hydrogen, alkyl or aryl, and
wherein the rings D 1 to D 4 each independently can be substituted once or frequently by hydrogen, chlorine, bromine, alkyl, or alkoxy.
Most preferred subclasses of this general formula (I) are the following:
compounds according to formula (XXI) ##STR8## compounds according to formula (XXIII): ##STR9## compounds according to formula (XXV): ##STR10## compounds according to formula (XXVII) ##STR11## compounds according to formula (XXIX): ##STR12##
In the formulas of these subclasses R1, R2, R17 and R18 have the same meaning as R3, and B1, B2, the other R symbols, T, and the D symbols are defined as hereinbefore, and α is 0 or 1.
Some specific infra-red absorbing dyes (IRD) corresponding to general formula (I) or to one of the preferred subclasses defined above which are chosen for the determination of specific spectral characteristics are listed below. A reference number is designated to them by which they will be identified in the tables furtheron of the description and examples: ##STR13##
Further suitable prior art dyes included in the experimental investigation of spectral parameters are represented by following formulas:
IRD-14 is a commercial product known as CYASORB IR165, marketed by American Cyanamid Co, Glendale Protective Technologie Division, Woodbury, N.Y. It is a mixture of two parts of the molecular non-ionic form (IRD-14a) and three parts of the ionic form (IRD-14b) represented by: ##STR14##
Other preferred IR-dyes, especially for irradiation with a laser source with an emission spectrum of about 830 nm belong to the scope of the following general formulas. ##STR15## wherein X, X' each independently represents O, S
R 70 -R 74 each independently may represent hydrogen, alkyl or aryl;
R 70 together with R 72 , R 72 together with R 74 , R 71 together with R 73 ,
R 70 together with R 72 and R 74 may form a carbocyclic ring
R 72 may also represent halogen, NR 88 R 89 (R 88 ,R 89 each independently represents alkyl, aryl, or may form a (hetero)cyclic ring), PR 88 R 89 , ester-COOR 92 (R 92 represents alkyl, or aryl), barbituric acid group (with optionally substituted N-atoms)
R 71 or R 73 may represents: --OCOR 93 ; R 93 represents alkyl, or aryl.
R 77 together with R 78 , R78 together with R 79 , R 79 together with R 80 ,
R 81 together with R 82 , R 82 together with R 83 , R 83 together with R 84 may form an annulated benzoring optionally substituted with a carbocyclic acid, ester or sulpho group.
R 78 , R 79 , R 82 , R 83 each independently may represent hydrogen, alkyl, aryl, halogen, ester, carbocyclic acid, amide, amine, nitrile, alkoxy, aryloxy, or sulpho group.
R 85 , R 86 , R 87 , R 88 each independently may represent an alkyl group,
R 85 together with R 86 , R 87 together with R 88 may form a cyclic (spiro) ring.
R 75 , R 76 each independently represents an alkyl, aryl group; --C n H 2n SO 3 M (n represents an integer from 2 to 4 and M H or positively charged counterion); --C n H 2n COOM (n represents an integer from 1 to 5 and M H or positively charged counterion); --C n H 2n COOR 94 (n represents an integer from 1 to 5 and R 94 alkyl, or aryl group); --L1-CONHSO 2 R 95 (L1 represents --C n H 2n -- with n an integer from 1 to 4 and R 95 alkyl or aryl). ##STR16## R 96 , R 102 represents alkyl, or aryl group; --C n H 2n SO 3 M (n represents an integer from 2 to 4 and M H or positively charged counterion); --C n H 2n COOM (n represents an integer from 1 to 5 and M H or positively charged counterion); --C n H 2n COOR 103 (n represents an integer from 1 to 5 and R 103 alkyl, or aryl group); --L1-CONHSO 2 R 104 (L1 represents --C n H 2n -- with n an integer from 1 to 4 and R 104 alkyl or aryl).
R 97 , R 98 R 100 , R 101 may each independently represent: hydrogen, alkyl, aryl; R 97 together with R 98 , R 100 together with R 101 may form an annulated benzoring.
R 98 may represent: hydrogen, alkyl, aryl, halogen, ester, or --SO2R 105 (R 105 represents an alkyl or aryl). ##STR17## R 106 , R 107 , R 108 , R 109 each independently may represent alkyl, aryl group; --C n H 2n SO 3 M represents an integer from 2 to 4 and M H or positively charged counterion); --C n H 2n COOM (n represents an integer from 1 to 5 and M H or positively charged counterion); --C n H 2n COOR 117 (n represents an integer from 1 to 5 and R 117 alkyl, or aryl group);
--L1-CONHSO 2 R 118 (L1 represents --C n H 2n -- with n an integer from 1 to 4 and R 118 alkyl or aryl).
R 110 , R 111 , R 112 , R 113 each independently represents: hydrogen, alkyl, or aryl group.
R 114 , R 115 , R 116 each independently may represent: hydrogen, alkyl, or aryl group; R 115 represents halogen, ester, or --SO2R 119 (R 119 represents alkyl, or aryl). ##STR18## R 120 , R 121 , R 122 , R 123 R 124 , R 125 , R 126 , R 127 : each independently may represent alkyl, aryl group; --C n H 2n SO 3 M (n represents an integer from 2 to 4 and M H or positively charged counterion); --C n H 2n COOM (n represents an integer from 1 to 5 and M H or positively charged counterion); --C n H 2n COOR 131 (n represents an integer from 1 to 5 and R 131 alkyl, or aryl group); --L1-CONHSO 2 R 132 (L1 represents --C n H 2n -- with n an integer from 1 to 4 and R 132 alkyl or aryl).
R 120 together with R 121 , R 122 together with R 123 , R 124 together with R 125 , R 126 together with R 127 may form a cyclic ring.
R 128 , R 129 , R 130 : each independently may represents hydrogen, alkyl, or aryl group; R 129 may represent: halogen, ester, or --SO2R 133 (R 133 represents alkyl, or aryl). ##STR19## R 134 , R 137 , R 138 , R 141 each independently may represent: hydrogen, alkyl, or aryl
R 134 together with R 135 , R 141 together with R 140 may form a carbocyclic ring.
R 135 together with R 136 , R 139 together with R 140 may form a carbocyclic ring.
R 135 , R 136 , R 139 1 , R 140 each independently may represent: hydrogen, alkyl, aryl group; --C n H 2n SO 3 M (n represents an integer from 2 to 4 and M H or positively charged counterion); --C n H 2n COOM (n represents an integer from 1 to 5 and M H or positively charged counterion); ##STR20## R 142 , R 143 , R 144 , R 145 each independently represents alkyl, aryl group; --C n H 2n SO 3 M represents an integer from 2 to 4 and M H or positively charged counterion); --C n H 2n COOM (n represents an integer from 1 to 5 and M H or positively charged counterion); --C n H 2n COOR 146 (n represents an integer from 1 to 5 and R 146 alkyl, or aryl group); --L1-CONHSO 2 R 147 (L1 represents --C n H 2n -- with n an integer from 1 to 4 and R 147 alkyl or aryl).
R142 together with R143, R144 together with R145 may form a cyclic ring.
The charge of the dyes can be compensated by any (intermolecular or intramolecular) counterion.
The IR-dyes are present preferably in an amount between 1 and 60 parts, more preferably between 3 and 50 parts by weight of the total amount of said IR-sensitive top layer.
The alkali soluble polymers used in this layer are preferably hydrophobic and ink accepting polymers as used in conventional positive or negative working PS-plates e.g. carboxy substituted polymers etc. More preferably is a phenolic resin such as polyvinylfenol or a novolac polymer. Most preferred is a novolac polymer. Typical examples of these polymers are described in DE-A-4 007 428, DE-A-4 027 301 and DE-A-4 445 820. The hydrophobic polymer used in connection with the present invention is further characterised by insolubility in water and at least partial solubility/swellability in an alkaline solution and/or at least partial solubility in water when combined with a cosolvent.
Furthermore this IR-sensitive layer is preferably a visible light- and UV-light desensitised layer. Still further said layer is preferably thermally hardenable. This preferably visible light- or UV-light desensitised layer does not comprise photosensitive ingredients such as diazo compounds, photoacids, photoinitiators, quinone diazides, sensitisers etc. which absorb in the wavelength range of 250 nm to 650 nm. In this way a daylight stable printing plate can be obtained.
Said IR-sensitive layer preferably also includes a low molecular acid, more preferably a carboxylic acid, still more preferably a benzoic acid, most preferably 3,4,5-trimethoxybenzoic acid or a benzophenone, more preferably trihydroxybenzophenone.
The ratio between the total amount of low molecular acid or benzophenone and polymer in the IR-sensitive layer preferably ranges from 2:98 to 40:60, more preferably from 5:95 to 30:70. The total amount of said IR-sensitive layer preferably ranges from 0.1 to 10 g/m 2 , more preferably from 0.3 to 2 g/m 2 .
In the IR-sensitive layer a difference in the capacity of being penetrated and/or solubilised by the alkaline developer containing SiO 2 and M 2 O in a molar ratio of 0.5 to 1.5 and a concentration of SiO 2 of 0.5 to 5% by weight is generated upon image-wise exposure for an alkaline developer according to the invention.
In the imaging element according to the present invention, the lithographic base can be an anodised aluminum. A particularly preferred lithographic base is an electrochemically grained and anodised aluminum support. The anodised aluminum support may be treated to improve the hydrophilic properties of its surface. For example, the aluminum support may be silicated by treating its surface with sodium silicate solution at elevated temperature, e.g. 95° C. Alternatively, a phosphate treatment may be applied which involves treating the aluminum oxide surface with a phosphate solution that may further contain an inorganic fluoride. Further, the aluminum oxide surface may be rinsed with a citric acid or citrate solution. This treatment may be carried out at room temperature or can be carried out at a slightly elevated temperature of about 30 to 50° C. A further interesting treatment involves rinsing the aluminum oxide surface with a bicarbonate solution. Still further, the aluminum oxide surface may be treated with polyvinylphosphonic acid, polyvinylmethylphosphonic acid, phosphoric acid esters of polyvinyl alcohol, polyvinylsulphonic acid, polyvinylbenzenesulphonic acid, sulphuric acid esters of polyvinyl alcohol, and acetals of polyvinyl alcohols formed by reaction with a sulphonated aliphatic aldehyde. It is further evident that one or more of these post treatments may be carried out alone or in combination. More detailed descriptions of these treatments are given in GB-A-1 084 070, DE-A-4 423 140, DE-A-4 417 907, EP-A-659 909, EP-A-537 633, DE-A-4 001 466, EP-A-292 801, EP-A-291 760 and U.S. Pat. No. 4,458,005.
According to another embodiment in connection with the present invention, the lithographic base having a hydrophilic surface comprises a flexible support, such as e.g. paper or plastic film, provided with a cross-linked hydrophilic layer. A particularly suitable cross-linked hydrophilic layer may be obtained from a hydrophilic binder cross-linked with a cross-linking agent such as formaldehyde, glyoxal, polyisocyanate or a hydrolysed tetraalkylorthosilicate. The latter is particularly preferred.
As hydrophilic binder there may be used hydrophilic (co)polymers such as for example, homopolymers and copolymers of vinyl alcohol, acrylamide, methylol acrylamide, methylol methacrylamide, acrylic acid, methacrylic acid, hydroxyethyl acrylate, hydroxyethyl methacrylate or maleic anhydride/vinylmethylether copolymers. The hydrophilicity of the (co)polymer or (co)polymer mixture used is preferably the same as or higher than the hydrophilicity of polyvinyl acetate hydrolyzed to at least an extent of 60 percent by weight, preferably 80 percent by weight.
The amount of crosslinking agent, in particular of tetraalkyl orthosilicate, is preferably at least 0.2 parts by weight per part by weight of hydrophilic binder, more preferably between 0.5 and 5 parts by weight, most preferably between 1.0 parts by weight and 3 parts by weight.
A cross-linked hydrophilic layer in a lithographic base used in accordance with the present embodiment preferably also contains substances that increase the mechanical strength and the porosity of the layer. For this purpose colloidal silica may be used. The colloidal silica employed may be in the form of any commercially available water-dispersion of colloidal silica for example having an average particle size up to 40 nm, e.g. 20 nm. In addition inert particles of larger size than the colloidal silica can be added e.g. silica prepared according to Stober as described in J. Colloid and Interface Sci., Vol. 26, 1968, pages 62 to 69 or alumina particles or particles having an average diameter of at least 100 nm which are particles of titanium dioxide or other heavy metal oxides. By incorporating these particles the surface of the cross-linked hydrophilic layer is given a uniform rough texture consisting of microscopic hills and valleys, which serve as storage places for water in background areas.
The thickness of a cross-linked hydrophilic layer in a lithographic base in accordance with this embodiment may vary in the range of 0.2 to 25 μm and is preferably 1 to 10 μm.
Particular examples of suitable cross-linked hydrophilic layers for use in accordance with the present invention are disclosed in EP-A-601 240, GB-P-1 419 512, FR-P-2 300 354, U.S. Pat. No. 3,971,660, U.S. Pat. No. 4,284,705 and EP-A-514 490.
As flexible support of a lithographic base in connection with the present embodiment it is particularly preferred to use a plastic film e.g. substrated polyethylene terephthalate film, cellulose acetate film, polystyrene film, polycarbonate film etc . . . . The plastic film support may be opaque or transparent.
It is particularly preferred to use a polyester film support to which an adhesion improving layer has been provided. Particularly suitable adhesion improving layers for use in accordance with the present invention comprise a hydrophilic binder and colloidal silica as disclosed in EP-A-619 524, EP-A-620 502 and EP-A-619 525. Preferably, the amount of silica in the adhesion improving layer is between 200 mg per m 2 and 750 mg per m 2 . Further, the ratio of silica to hydrophilic binder is preferably more than 1 and the surface area of the colloidal silica is preferably at least 300 m 2 per gram, more preferably at least 500 m2 per gram.
Image-wise exposure in connection with the present invention is an image-wise scanning exposure involving the use of a laser that operates in the infrared or near-infrared, i.e. wavelength range of 700-1500 nm. Most preferred are laser diodes emitting in the near-infrared. Exposure of the imaging element can be performed with lasers with a short as well as with lasers with a long pixel dwell time. Preferred are lasers with a pixel dwell time between 0.005 μs and 20 μs.
After the image-wise exposure the heat mode imaging element is developed by rinsing it with an aqueous alkaline solution. The aqueous alkaline solutions used in the present invention are those that are used for developing conventional positive working presensitised printing plates and have preferably a pH between 11.5 and 14. Thus the imaged parts of the top layer that were rendered more penetrable for the aqueous alkaline solution upon exposure are cleaned-out whereby a positive working printing plate is obtained.
In the present invention, the composition of the developer used is also very important.
Therefore, to perform development processing stably for a long time period particularly important are qualities such as strength of alkali and the concentration of silicates in the developer. Under such circumstances, the present inventors have found that a rapid high temperature processing can be performed, that the amount of the replenisher to be supplemented is low and that a stable development processing can be performed over a long time period of the order of not less than 3 months without exchanging the developer only when the developer having the foregoing composition is used.
The developers and replenishers for developer used in the invention are preferably aqueous solutions mainly composed of alkali metal silicates and alkali metal hydroxides represented by MOH or their oxyde, represented by M 2 O, wherein said developer comprises SiO 2 and M 2 O in a molar ratio of 0.5 to 1.5. As such alkali metal silicates, preferably used are, for instance, sodium silicate, potassium silicate, lithium silicate and sodium metasilicate. On the other hand, as such alkali metal hydroxides, preferred are sodium hydroxide, potassium hydroxide and lithium hydroxide.
The developers used in the invention may simultaneously contain other alkaline agents. Examples of such other alkaline agents include such inorganic alkaline agents as ammonium hydroxide, sodium tertiary phosphate, sodium secondary phosphate, potassium tertiary phosphate, potassium secondary phosphate, ammonium tertiary phosphate, ammonium secondary phosphate, sodium bicarbonate, sodium carbonate, potassium carbonate and ammonium carbonate; and such organic alkaline agents as mono-, di- or triethanolamine, mono-, di- or trimethylamine, mono-, di- or triethylamine, mono- or di- isopropylamine, n-butylamine, mono-, di- or triisopropanolamine, ethyleneimine, ethylenediimine and tetramethylammonium hydroxide.
In the present invention, particularly important is the molar ratio in the developer of [SiO 2 ]/[M 2 O], which is generally 0.6 to 1.5, preferably 0.7 to 1.3. This is because if the molar ratio is less than 0.6, great scattering of activity is observed, while if it exceeds 1.5, it becomes difficult to perform rapid development and the dissolving out or removal of the light-sensitive layer on non-image areas is liable to be incomplete. In addition, the concentration of SiO 2 in the developer and replenisher preferably ranges from 1 to 4 % by weight. Such limitation of the concentration of SiO 2 makes it possible to stably provide lithographic printing plates having good finishing qualities even when a large amount of plates according to the invention are processed for a long time period.
In a particular preferred embodiment, an aqueous solution of an alkali metal silicate having a molar ratio [SiO 2 ]/[M 2 O], which ranges from 1.0 to 1.5 and a concentration of SiO 2 of 1 to 4% by weight is used as a developer. In such case, it is a matter of course that a replenisher having alkali strength equal to or more than that of the developer is employed. In order to decrease the amount of the replenisher to be supplied, it is advantageous that a molar ratio, [SiO 2 ]/[M 2 O], of the replenisher is equal to or smaller than that of the developer, or that a concentration of SiO 2 is high if the molar ratio of the developer is equal to that of the replenisher.
In the developers and the replenishers used in the invention, it is possible to simultaneously use organic solvents having solubility in water at 20° C. of not more than 10% by weight according to need. Examples of such organic solvents are such carboxilic acid esters as ethyl acetate, propyl acetate, butyl acetate, amyl acetate, benzyl acetate, ethylene glycol monobutyl acetate, butyl lactate and butyl levulinate; such ketones as ethyl butyl ketone, methyl isobutyl ketone and cyclohexanone; such alcohols as ethylene glycol monobutyl ether, ethylene glycol benzyl ether, ethylene glycol monophenyl ether, benzyl alcohol, methylphenylcarbinol, n-amyl alcohol and methylamyl alcohol; such alkyl-substituted aromatic hydrocarbons as xylene; and such halogenated hydrocarbons as methylene dichloride and monochlorobenzene. These organic solvents may be used alone or in combination. Particularly preferred is benzyl alcohol in the invention. These organic solvents are added to the developer or replenisher therefor generally in an amount of not more than 5% by weight and preferably not more than 4% by weight.
The developers and replenishers used in the present invention may simultaneously contain a surfactant for the purpose of improving developing properties thereof. Examples of such surfactants include salts of higher alcohol (C8˜C22) sulfuric acid esters such as sodium salt of lauryl alcohol sulfate, sodium salt of octyl alcohol sulfate, ammonium salt of lauryl alcohol sulfate, Teepol B-81 (trade mark, available from Shell Chemicals Co., Ltd.) and disodium alkyl sulfates; salts of aliphatic alcohol phosphoric acid esters such as sodium salt of cetyl alcohol phosphate; alkyl aryl sulfonic acid salts such as sodium salt of dodecylbenzene sulfonate, sodium salt of isopropylnaphthalene sulfonate,sodium salt of dinaphthalene disulfonate and sodium salt of metanitrobenzene sulfonate; sulfonic acid salts of alkylamides such as C 17 H 33 CON(CH 3 )CH 2 CH 2 SO 3 Na and sulfonic acid salts of dibasic aliphatic acid esters such as sodium dioctyl sulfosuccinate and sodium dihexyl sulfosuccinate. These surfactants may be used alone or in combination. Particularly preferred are sulfonic acid salts. These surfactants may be used in an amount of generally not more than 5% by weight and preferably not more than 3% by weight.
In order to enhance developing stability of the developers and replenishers used in the invention, the following compounds may simultaneously be used.
Examples of such compounds are neutral salts such as NaCl, KCl and KBr as disclosed in JN-A-58-75 152; chelating agents such as EDTA and NTA as disclosed in JN-A-58-190 952 (U.S. Pat. No. 4,469,776), complexes such as [Co(NH3)6]C13 as disclosed in JN-A-59-121 336 (U.S. Pat. No. 4,606,995); ionizable compounds of elements of the group IIa, IIIa or IIIb of the Periodic Table such as those disclosed in JN-A-55-25 100; anionic or amphoteric surfactants such as sodium alkyl naphthalene sulfonate and N-tetradecyl-N,N-dihydroxythyl betaine as disclosed in JN-A-50-51 324; tetramethyldecyne diol as disclosed in U.S. Pat. No.4,374,920; non-ionic surfactants as disclosed in JN-A-60-213 943; cationic polymers such as methyl chloride quaternary products of p-dimethylaminomethyl polystyrene as disclosed in JN-A-55-95 946; amphoteric polyelectrolytes such as copolymer of vinylbenzyl trimethylammonium chloride and sodium acrylate as disclosed in JN-A-56-142 528; reducing inorganic salts such as sodium sulfite as disclosed in JN-A-57-192 952 (U.S. Pat. No. 4,467,027) and alkaline-soluble mercapto compounds or thioether compounds such as thiosalicylic acid, cysteine and thioglycolic acid; inorganic lithium compounds such as lithium chloride as disclosed in JN-A-58-59 444; organic lithium compounds such as lithium benzoate as disclosed in JN-A-50 34 442; organometallic surfactants containing Si, Ti or the like as disclosed in JN-A-59-75 255; organoboron compounds as disclosed in JN-A-59-84 241 (U.S. Pat. No. 4,500,625); quaternary ammonium salts such as tetraalkylammonium oxides as disclosed in EP-A-101 010; and bactericides such as sodium dehydroacetate as disclosed in JN-A-63-226 657.
In the method for development processing of the present invention, any known means of supplementing a replenisher for developer may be employed. Examples of such methods preferably used are a method for intermittently or continuously supplementing a replenisher as a function of the amount of PS plates processed and time as disclosed in JN-A-55-115 039 (GB-A-2 046 931), a method comprising disposing a sensor for detecting the degree of light-sensitive layer dissolved out in the middle portion of a developing zone and supplementing the replenisher in proportion to the detected degree of the light-sensitive layer dissolved out as disclosed in JN-A-58-95 349 (U.S. Pat. No. 4,537,496); a method comprising determining the impedance value of a developer and processing the detected impedance value by a computer to perform supplementation of a replenisher as disclosed in GB-A-2 208 249.
The printing plate of the present invention can also be used in the printing process as a seamless sleeve printing plate. In this option the printing plate is soldered in a cylindrical form by means of a laser. This cylindrical printing plate which has as diameter the diameter of the print cylinder is slided on the print cylinder instead of applying in a classical way a classically formed printing plate. More details on sleeves are given in "Grafisch Nieuws" ed. Keesing, 15, 1995, page 4 to 6.
After the development of an image-wise exposed imaging element with an aqueous alkaline solution and drying, the obtained plate can be used as a printing plate as such. However, to improve durability it is still possible to bake said plate at a temperature between 200° C. and 300° C. for a period of 30 seconds to 5 minutes. Also the imaging element can be subjected to an overall post-exposure to UV-radiation to harden the image in order to increase the run length of the printing plate.
The following examples illustrate the present invention without limiting it thereto. All parts and percentages are by weight unless otherwise specified.
EXAMPLES
Example 1
Positive Working Thermal Plate Based on an Alkali-Soluble Binder
Preparation of the Lithographic Base
A 0.20 mm thick aluminum foil was degreased by immersing the foil in an aqueous solution containing 5 g/l of sodium hydroxide at 50° C. and rinsed with demineralized water. The foil was then electrochemically grained using an alternating current in an aqueous solution containing 4 g/l of hydrochloric acid, 4 g/l of hydroboric acid and 5 g/l of aluminum ions at a temperature of 35° C. and a current density of 1200 A/m 2 to form a surface topography with an average center-line roughness Ra of 0.5 mm.
After rinsing with demineralized water the aluminum foil was then etched with an aqueous solution containing 300 g/l of sulfuric acid at 60° C. for 180 seconds and rinsed with demineralized water at 25° C. for 30 seconds.
The foil was subsequently subjected to anodic oxidation in an aqueous solution containing 200 g/l of sulfuric acid at a temperature of 45° C., a voltage of about 10 V and a current density of 150 A/m 2 for about 300 seconds to form an anodic oxidation film of 3.00 g/m 2 of Al 2 O 3 then washed with demineralized water, posttreated with a solution containing polyvinylphosphonic acid and then with a solution containing aluminum trichloride, subsequently rinsed with demineralized water at 20° C. during 120 seconds and dried.
Preparation of the IR-sensitive Layer
The IR-sensitive layer was coated from a 4.65% wt solution in tetrahydrofuran/methoxypropanol 60/40 at a wet thickness of 30 μm.
The resulting IR-sensitive layer contained 10% of IR-dye compound I and 90% of ALNOVOL PN430™.
This material was imaged with a GERBER C42T™ internal drum platesetter at 12,000 rpm and 2540 dpi. The power level of the laser in the image plane was 4 W. After IR-exposure no layer damage, as a result of ablation, could be observed.
After exposure the material was developed in an alkaline developing solution (EP 240 developer commercially available from Agfa), dissolving very rapidly the IR-exposed areas, resulting in a positive working plate.
The plate was printed on a Heidelberg GTO46 printing machine with a conventional ink (K+E) and fountain solution (Rotamatic), resulting in good prints, i.e. no scumming in IR-exposed areas and good ink-uptake in the non-exposed areas.
Example 2
Positive Working Thermal Plate Based on an Alkali-Soluble Binder
The lithographic base was prepared as described in example 1.
The IR-sensitive layer was coated from a 4.65% wt solution in tetrahydrofuran/methoxypropanol 60/40 at a wet thickness of 30 μm.
The resulting IR-sensitive layer contained 4.7% of IR-dye compound II, 78.1% of ALNOVOL PN430™ and 17.2% of trihydroxybenzophenone. This material was imaged with a GERBER C42T™ internal drum platesetter at 12,000 rpm and 2540 dpi. The power level of the laser in the image plane was 4 W. After IR-exposure no layer damage, as a result of ablation, could be observed.
After exposure the material was developed in an alkaline developing solution (EP 26 developer commercially available from Agfa), dissolving very rapidly the IR-exposed areas, resulting in a positive working plate.
The plate was printed on a Heidelberg GTO46 printing machine with a conventional ink (K+E) and fountain solution (Rotamatic), resulting in good prints, i.e. no scumming in IR-exposed areas and good ink-uptake in the non-exposed areas.
Example 3
Positive Working Thermal Plate Based on an Alkali-soluble Binder
The lithographic base was prepared as described in example 1.
The IR-sensitive layer was coated from a 4.65% wt solution in tetrahydrofuran/methoxypropanol 60/40 at a wet thickness of 30 μm. The resulting IR-sensitive layer contained 9.1% of IR-dye compound II, 74.5% of ALNOVOL PN430™ and 16.4% of trihydroxybenzophenone.
This material was imaged with a GERBER C42T™ internal drum platesetter at 12,000 rpm and 2540 dpi. The power level of the laser in the image plane was 4 W. After IR-exposure no layer damage, as a result of ablation, could be observed.
After exposure the material was developed in an alkaline developing solution (EP 26 developer commercially available from Agfa), dissolving very rapidly the IR-exposed areas, resulting in a positive working plate.
The plate was printed on a Heidelberg GTO46 printing machine with a conventional ink (K+E) and fountain solution (Rotamatic), resulting in good prints, i.e. no scumming in IR-exposed areas and good ink-uptake in the non-exposed areas. | According to the present invention there is provided a method for making lithographic printing plates including the following steps
a) preparing a heat mode imaging element consisting of a lithographic base with a hydrophilic surface and a top layer which top layer is sensitive to IR-radiation, comprises a polymer, soluble in an aqueous alkaline solution and is unpenetrable for an alkaline developer containing SiO 2 as silicates;
b) exposing imagewise said heat mode imaging element to IR-radiation;
c) developing said imagewise exposed heat mode imaging element with said alkaline developer so that the exposed areas of the top layer are dissolved and the unexposed areas of the top layer remain undissolved characterized in that said top layer includes an IR-dye selected from the group consisting of indoaniline dyes, cyanine dyes, merocyanine dyes, oxonol dyes, porphine derivatives, anthraquinone dyes, merostyryl dyes, pyrylium compounds, diphenyl and triphenyl azo compounds and squarylium derivatives. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates generally to the concept of ventilation of the garage and more specifically to the operation of a power ventilation system, which is controlled by a movable barrier operator.
BACKGROUND OF THE INVENTION
[0002] Modern garages are designed with some form of passive ventilation. Methods used in present construction technology include ridge ventilation and roof ventilation usually in combination with soffit ventilation.
[0003] These techniques of ventilation are used in order to protect the roof and attic from the environmental hazards of heat and moisture buildup. They do nothing to eliminate the fumes and odor which usually exists in the garage. This invention removes the fumes and odors that are present in the garage.
SUMMARY OF THE INVENTION
[0004] One aspect of the invention is to provide a power ventilation system used to eliminate or reduce the fumes and odors created within the garage. A second aspect of this invention is to provide control of the power ventilation system so that this reduction of fumes and odors occurs when it is needed, rather than continuously operating.
[0005] In one embodiment of the present invention, a standard power ventilation system is controlled by the movable barrier operator. In another embodiment, the ventilation system is interfaced to the weather seal for the garage door for a system that is easier to install system and is controlled by the movable barrier operator. In a third embodiment the door is modified in order to allow for the power ventilation of the garage when the barrier is closed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 illustrates the prior art ridge ventilation with soffit vents.
[0007] FIG. 2 illustrates the prior art roof ventilation with soffit vents.
[0008] FIG. 3 illustrates the prior art roof ventilation with soffit vents and the effects of the ceiling being drywalled.
[0009] FIG. 4 illustrates an inside view of the garage with a power vent fan.
[0010] FIG. 5 illustrates an exhaust fan mounted to the side of the garage.
[0011] FIG. 6 illustrates an exhaust fan ducted to a standard garage vent.
[0012] FIG. 7 illustrates a weather seal.
[0013] FIG. 8 illustrates detail of the weather seal acting as a duct.
[0014] FIG. 9 illustrates ports added to the garage door.
[0015] FIG. 10 illustrates a method of coupling the stationary fan to the movable door.
DETAILED DESCRIPTION OF THE INVENTION
[0016] A filler understanding of the invention will be accomplished from the following explanation of a number of embodiments of the present invention.
[0017] FIG. 1 is one representation of the present state of the art in ventilation of a garage. The garage 100 has ridge ventilation and soffit ventilation. Air usually flows in through the soffit vents 104 and out through the ridge vents 102 . This air flow allows the attic space to remain cooler and drier extending the life of the roof. This system of air flow is also accomplished in the system illustrated in FIG. 2 . In FIG. 2 , the ridge vent is replaced by either attic vent 106 or face vent 108 . Again the usual air flow is from the soffit 104 to the vent.
[0018] Current garage ventilation systems do not remove fumes and odor which exist at ground level of the floor. In fact, as garage technology has progressed, the use of drywalled ceilings has increased, increasing the trapping of the fumes within the garage. In FIG. 3 , a basic cutaway view removes the garage's front exterior face, and shows the drywall 202 restricting the air flow 204 from passing through occupation area 208 . Instead, the airflow passes from the soffit 104 through the attic 206 and out the roof vent 106 . This does nothing to remove fumes and odor from the occupation area 208 .
[0019] The fumes and odor are generated by items usually stored within the garage. Many homeowners keep their garbage within the garage until it is time to be picked up in order to protect it from pests and varmints. The garbage can create a very unpleasant odor and stays within the garage. Paint, gasoline, and oil are also usually stored within the garage. Properly sealed they would not be a problem, but usually they are not properly sealed and, therefore, create fumes and odors within the garage. The family vehicle can also be a great creator of fumes and odors within the garage. The vehicle not only produces dangerous fumes while running, but also has a tendency to release those fumes after being parked within the garage. These fumes not only create a problem when the owners of the home enter the garage but also have the possibility of seeping into the home through the access door or, if there are rooms above the garage, through the floor of the room.
[0020] Ideally in order to remove these fumes a system would be set up to exhaust them from the area when needed. This can be accomplished using a power exhaust fan.
[0021] In general the garage is used as a passageway from the house and to access at least one vehicle. In order to move the vehicle or to exit the garage the garage door must be moved. Movement of the garage door can be detected either by a movable barrier operator in the form of a garage door operator or any other form of detection device. For illustration purposes, the detection device use herein is a garage door operator but, of course, other methods such as a switch and optical detector ultrasonic detector etc. could be used.
[0022] FIG. 4 shows an inside view of garage 16 . Within the garage 16 is a movable barrier operator 12 . The operation of a movable barrier operator is well known in the art. The movable barrier operator 12 is in communication with an exhaust fan 300 . The exhaust fan 300 can either be powered by the movable barrier operator 12 , or it can be powered from the outlet 13 and controlled via the communications to the movable barrier operator 12 .
[0023] The communications between the movable barrier operator 12 and the exhaust fan 300 can be performed by wires or wirelessly. When performed by wires, the communications can be as simple as the movable barrier operator 12 applying power to the exhaust fan 300 . When the communications contains a data stream conveyed either by wire or wirelessly, a data stream can contain instructions to the fan or status information from the movable barrier operator. If the data stream contains instructions, the instructions can be on or off, or speed and time of operation information. If the data stream is the status information from the movable barrier operator, the exhaust fan can make a decision as to how to operate. No matter how the system is partitioned, a control system is created between the movable barrier operator 12 and the exhaust fan 300 .
[0024] Whenever the decision as to how to operate is being performed, the decision would be made intelligently according to the sequence of operations. Referring again to FIG. 4 , the movable barrier operator 12 has more than one method of being activated. A wall control 39 is shown next to the access door to the garage. External to the garage, a transmitter 30 is also shown. If the movable barrier operator 12 is first activated by wall control 39 and then closed by transmitter 30 , the control system will assume that the homeowner has left the garage and, therefore, can either minimize the amount of time which exhaust fan 300 is activated or not activated it at all. If the sequence is reversed and the door is opened via transmitter 30 and closed by wall control 39 , the control system can assume that a vehicle has been placed within the garage and can, therefore, activate the exhaust fan 300 for a longer period of time or delay activation waiting for the exhaust fumes to seep out of the vehicle's exhaust. For each of the potential sequences of operation of the movable barrier operator 12 the control system includes appropriate activation instructions.
[0025] The exhaust fan may have a number of physical locations. FIG. 4 shows one embodiment. In a garage where the ceiling has been drywalled, the fan only needs to be placed into the drywall similar to a whole house ventilation fan or a bathroom fan. When the fan is activated, the air from the garage is pulled into the attic and forced through the attic ventilation system.
[0026] FIG. 5 shows another embodiment of the system. In FIG. 5 , the exhaust fan 501 is mounted to the side of the garage. FIG. 6 shows yet another embodiment in which the exhaust fan 400 is ducted to the outside world through one of the standard vents 106 of the garage. This allows the exhaust fan 400 to be mounted without concerns for creating holes in the building.
[0027] Yet another advantage of the present invention occurs when the exhaust fan becomes integrated with the barrier itself. As shown in FIG. 7 , in one embodiment the weather seal 700 for the barrier becomes the duct which carries the exhaust air to the outside world. FIG. 8 is a detailed drawing of a small section of FIG. 7 showing the exhaust fan 804 and the vents 802 in the weather seal 700 . The air moves from the exhaust fan 804 through a duct into the weather seal 700 . The weather seal 700 contains one or more vents 802 . The vent or vents 802 permit the air to exit the garage.
[0028] An integrated system could also be accomplished using a port or ports built into the garage door or bottom weather seal as shown in FIG. 9 . Port 900 allows the air to be forced out of the garage. The port 900 can have a flap door in the front to keep pests from entering the garage through the port. The system may include a second port 902 . Port 902 may be connected to a second exhaust fan or may be ducted to the first exhaust fan.
[0029] In order too allow the door to open and create an air flow into the port, the fan must be coupled to the port. An example of this coupling is shown in FIG. 10 . In FIG. 10 , a duct 1004 is coupled to the fan 1000 through an open coupling 1002 . The open coupling 1002 could be replaced with a flexible hood flap or any other connection which would allow the motion of the door yet still have the fan coupled to the barrier when the barrier is closed.
[0030] In another embodiment, the port could be replaced with the weather seal at the bottom of the door. The weather seal could be vented similar to the venting shown in FIGS. 7 and 8 . | A power ventilation system comprising an exhaust fan, a power supply, and a control system is provided for ventilation of a garage. The ventilation system may be controlled by a moveable barrier, interfaced to a weather seal of the garage door, or configured to allow power ventilation of the garage when the garage door is closed. | 5 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an ink-jet head used for an ink-jet printer and the manufacturing method for the same.
[0002] Conventional technology to utilize the piezoelectric effects of a piezoelectric element, as an actuating force for ink-emission by an ink-jet printer. For example, as described in Japanese Patent Publication No. 4-48622, it is an ink-jet head system in which an electrode layer is formed inside a fine groove formed on a piezoelectric substrate and further aforesaid electrode layer is covered with an insulating layer for forming an ink path.
[0003] The purpose of aforesaid insulating layer is to minimize deformation of the ink and to protect the electrode. It is demanded that aforesaid insulating layer is inactive on ink and the electrode and that it has affinity to the ink so that feeding of the ink into the flowing path is smooth. As the insulating layer having aforesaid properties, a resin layer composed of a poly-para-xylylene (also referred as a palylene layer) is disclosed in Japanese Utility Publication Open to Public Inspection No. 5-60844 and Japanese Patent Publication Open to Public Inspection (hereinafter, referred as JP) Nos. 6-238897, 6-286150 and 7-246702. Aforesaid resin layer is formed by a CVD (Chemical Vapor Deposition) method in which a solid di-para-xylylene dimmer is used as a deposition source. Namely, a stable di-radical para-xylylene monomer which occurred due to gassification and heat decomposition of di-para-xylylene dimmer is adsorbed on a substrate for polymerization reaction and thereby a layer is formed.
[0004] When an ink path is processed, ordinarily, after an electrode layer and an insulating layer are formed on a groove on a piezoelectric substrate, the other lid member is adhered thereon. Therefore, in the electrode side member on which a resin layer covers entirely, a resin layer is provided on an adhesive surface, causing deterioration of an adhesive agent and adhesive force so that life of the head is damaged.
[0005] Since aforesaid resin layer is liphobilic, in order to use a water-based ink which suits well with paper, it is necessary to cause aforesaid resin layer hydrophilic after surface processing. In aforesaid technologies, graft polymerization processing, plasma processing, coupling reaction processing, dipping processing using a chromic acid mixture solution and forming of an inorganic mill scale are disclosed. By the use of any of aforesaid conventional processing method of the ink path, the water-based ink emission performance cannot be maintained for a long time employing any of the above-mentioned processing.
SUMMARY OF THE INVENTION
[0006] The present invention was contrived viewing the above-mentioned situations. An objective is to provide an ink-jet head excellent in terms of water-based ink emission performance for a long time and life thereof.
[0007] The above-mentioned objective of the present invention can be attained by a method of manufacturing an ink-jet head in which an ink chamber having at least one vibration wall having an electrode layer on a piezoelectric ceramic substrate is composed of at least two members such as a member having the above-mentioned vibration wall and a member forming a fixed wall and aforesaid two or more members are integralized for constituting a chamber, followed by that a resin layer composed of poly-para-xylylene or its derivative is formed on an electrode layer in aforesaid chamber by means of a vapor phase polymerization method.
[0008] In the above-mentioned manufacturing method, the following issues are preferable examples:
[0009] 1. The above-mentioned resin layer is subjected to plasma processing;
[0010] 2. The above-mentioned electrode layer is composed of aluminum, tantalum or titanium;
[0011] 3. After the above-mentioned electrode layer is subjected to anodic oxidation processing, a resin layer composed of poly-para-xylylene or its derivative is formed.
[0012] The above-mentioned objective is attained by an ink-jet head having at least one vibration wall having an electrode layer on a piezoelectric ceramic substrate, wherein a resin layer composed of poly-para-xylylene or its derivative formed on all through the surface of inner wall of aforesaid chamber by means of the vapor phase polymerization method.
[0013] Namely, the present inventors discovered that life and ink emission performance for a long time can be obtained due to a reason assumed to be that all including an adhesive agent is shielded from ink, if a resin layer is formed by means of the CVD method after integralizing members forming the ink path. Further, it was also confirmed that the effects of the present invention can be provided more noticeably if aforesaid resin layer is subjected to plasma processing in aforesaid forming method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 shows an illustrated cross sectional view of an ink chamber.
[0015] [0015]FIG. 2 shows a perspective view of a piezoelectric ceramic substrate.
[0016] [0016]FIG. 3 shows a block diagram of a deposition device which conducts chemical deposition of the present invention.
[0017] FIGS. 4 ( a ) and 4 ( b ) are cross sectional views showing an adhesive portion between a piezoelectric ceramic substrate and a lid member.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Hereinafter, the present invention will be explained referred to embodiments. However, the embodiments of the present invention are not limited thereto.
[0019] [0019]FIG. 1 shows an illustrated cross sectional view of an ink chamber of the present invention.
[0020] In FIG. 1, numeral 1 represents a piezoelectric ceramic substrate containing a vibration wall, 2 represents a lid member which forms a fixed wall, 3 represents an electrode layer, 4 represents a resin layer (a perylene layer) and 5 represents an ink chamber.
[0021] As a piezoelectric ceramic constituting substrate 1 , any of conventional ones may be used. those having large filling density such as titanium acid zirconic acid lead are preferable in terms of piezoelectric performance. Lid member 2 is a flat plate joined on substrate 1 . The flat plate made of glass, ceramic, metal or plastic can be used.
[0022] [0022]FIG. 2 shows an example of a substrate 1 . A small groove (L: 30 mm, H: 360 μm and B: 70 μm) is processed on one side of a 1 mm—thickness substrate 1 . By joining lid member 2 on the processed surface of aforesaid substrate 1 , an ink chamber (L: 30 mm, H: 360 μm and B: 70 μm), an ink path, is constituted on the groove portion. One end of the ink chamber is connected with the ink feeding section, and the other end of ink chamber is connected to ink emission section.
[0023] As a preferable example of the present invention, the ink chamber of the present invention is formed by means of the following procedures:
[0024] 1. Electrode layer forming step
[0025] 2. Adhesion step
[0026] 3. Resin layer forming step
[0027] 4. Plasma processing step
[0028] 1. Electrode Layer Forming Sstep
[0029] In order to form electrode layer 3 on a small groove portion processed on substrate 1 with a thin layer (ordinarily, 0.5-5.0 μm), electrode layer 3 is formed by means of spattering. It is preferable that electrode layer 3 is made of aluminum, tantalum or titanium from the viewpoint of electrical properties, anti-corrosion property and processability. In order to improve anti-corrosion property and stability of electrode layer 3 , it is effect to provide anodic oxidation processing. Next, practical example of the anodic oxidation processing will be exhibited.
[0030] As an electrolytic solution, a mixture solution composed of 300 ml of ethylene alcohol and 30 ml of 3% tartaric acid whose pH was 7.0±0.5 (regulated with an aqueous ammonia) was used. A piezoelectric ceramic substrate on which 2 μm aluminum electrode layer was formed was immersed in aforesaid solution. In the solution, the electrode layer side was set to be positive, and was subjected to anodic oxidation in which the electrical current density was 1 mA/cm 2 and the current was constant-current until the voltage reaches 100 V and the voltage was constant-voltage of 100V after the voltage have reached 100V. When the electrical current density becomes 0.1 mA/cm 2 or less, the processing is finished.
[0031] 2. Adhesion Step
[0032] In the present invention, after the above-mentioned electrode layer is subjected to anodic oxidation, prior to the resin layer forming step, a step for adhering substrate 1 and lid member 2 is included.
[0033] In the adhesion step, before coating an adhesive agent, a processed surface on which a groove on substrate 1 and a joint surface for lid member 2 which covers the above-mentioned groove are subjected to cleaning and polishing depending upon their conditions. Following this, adhesive surfaces are respectively formed.
[0034] An adhesive surface on substrate 1 and an adhesive surface on lid member 2 are adhered with an epoxy-containing adhesive agent so that substrate 1 and lid member 2 become integral. After assembly, the adhesive surface is heated up to about 120° C. while being pressed. Aforesaid heating and pressing conditions are maintained for about 2 hours so that the adhesive agent is hardened. Due to aforesaid adhesive step, an adhesive agent layer, whose thickness is 1.0-2.0μm is formed between each adhesive layer. In addition, between integral substrate 1 and lid member 2 , an ink chamber, which forms an ink path, is constituted.
[0035] 3. Resin Layer Forming Step
[0036] After the adhesive step, integral substrate 1 and lid member 2 are subjected to chemical deposition which forms resin layer 4 .
[0037] [0037]FIG. 3 shows an example of a deposition device which conducts chemical deposition which forms resin layer 4 composed of poly-para-xylylene of the present invention or its derivative. The deposition device in FIG. 3 is composed of sublimation furnace 10 , heat decomposition furnace 20 and casting tank 30 . The above-mentioned sublimation furnace 10 , heat decomposition furnace 20 and casting tank 30 are connected by piping, as shown in FIG. 3, which forms a gas path. During deposition, the degree of vacuum of the above-mentioned deposition device is kept at 10 −3 to 1.0 Torr. Inside sublimation furnace 10 is kept at 100-200° C., inside heat decomposition furnace 20 is kept at 450-700° C. and inside casting tank 30 is kept at room temperature.
[0038] Inside sublimation furnace 10 , solid dimmer di-para-xylylene, which is a raw material of resin layer 4 , is subjected to gasification. In heat decomposition furnace 20 , heat decomposition in which gasificated dimmer (structural formula A) is subjected to heat decomposition for generating para-xylylene radical (structural formula B) is conducted. In casting tank 30 , a rotation stand which rotates at around 10 rpm is provided. On aforesaid rotation stand, integral substrate 1 and lid member 2 are located. Para-xylylene radical which occurred in heat decomposition furnace 20 adheres on substrate 1 and lid member 2 located on the rotation stand in casting tank 30 . In aforesaid casting tank 30 , together with adhering substrate 1 and lid member 2 , para-xylylene radical was subjected to vapor phase polymerization for forming a resin layer of poly-para-xylylene (structural formula C) having high molecular weight. Here, examples a resin layer composed of a poly-para-xylylene derivative will be exhibited in structural formula D.
[0039] Thickness of resin layer formed is preferably 1.0-10 μm from the viewpoint of covering and protecting the electrode layer for retaining insulation property. If it is too thick, movement of moving portion of the ink chamber is restricted.
[0040] Example of Forming Resin Layer
[0041] In the deposition device in FIG. 3, 50 g of di-para-xylylene (the raw material) was subjected to gasification in sublimation furnace 10 at 190° C. The gasificated di-para-xylylene was subjected to heat decomposition in heat decomposition furnace 20 at 680° C. for generating para-xylylene radical. The generated para-xylylene was introduced into casting tank 30 in which the pressure was evacuated to 0.1 Torr. In aforesaid casting tank 30 , a resin layer was formed on integral substrate 1 and lid member 2 for 4 hours. Due to this, on the inner wall inside the ink chamber, a resin layer having 3 μm thickness could be formed.
[0042] 4. Plasma Processing Step
[0043] When an ink chamber is constituted by means of the present invention, it is meritable that the resin layer formed in the above-mentioned step is subjected to plasma processing. As the plasma processing, the following processing is cited as a practical example.
(Processing conditions) Device: Parallel and flat type reacting vessel Raw material gas: oxygen Flow rate of gas: 50 sccm Pressure: 10 Pa Discharging method: High frequency (13.56 MHz, 200W) Processing time: 2 minutes
[0044] According to aforesaid processing, the resin layer is subjected to etching of 0.5 μm, and thereby the surface is activated. As a result, the contact angle of water of 85° before processing becomes 10°, after processing. Thus, wettability is improved. As another effective plasma processing, a method employing a micro-wave is cited. Gas to be used is not limited to oxygen. Nitrogen and other gasses and a mixed gas between oxygen and inactive gas are cited.
[0045] Comparative Test
[0046] In order to conduct a comparative test with an ink jet head of the present invention having an ink chamber formed as described above, a comparative ink jet head was constituted under the following procedure.
[0047] Substrate 1 in which electrode layer was formed on a groove was subjected to a resin layer forming step without integralizing with lid member 2 . Due to this, a resin layer was also formed on the adhesive surface of substrate 1 , too. Following this, the adhesive surface of substrate 1 in which the resin layer was formed and the adhesive surface of lid member 2 were adhered for preparing a comparative ink jet head.
[0048] As a comparative test, a continuous emitting test was conducted. The ink jet head of the present invention could emit at impressing voltage of 20 V. However, in the case of a comparative ink jet head, it was necessary to increase the impressing voltage to 40 V. In addition, the comparative ink jet head became impossible to emit after 20 hours. However, the ink jet head of the present invention could stably emit for 100 hours or more.
[0049] FIGS. 4 ( a ) and 4 ( b ) are illustrative cross sectional view showing adhesive portions between substrate 1 and lid member 2 . As described in FIG. 4( a ), in the ink jet head of the present invention, a resin layer forming step is conducted after integralizing substrate 1 and lid member 2 by means of the adhesive step. Therefore, the adhesive surface of substrate 1 and that of lid member 2 are fixed only with adhesive agent 8 . On the contrary, in the case of the comparative ink jet head, the adhesive step is conducted after substrate 1 is subjected to the resin layer forming step. Therefore, adhesive agent layer 8 fixes the adhesive surface of substrate 1 and the adhesive surface of lid member 2 through resin layer 4 . Accordingly, it is assumed that, in the case of the comparative ink jet head, adhesive force between substrate 1 having a vibration wall and lid member 2 forming a fixing wall is insufficient.
[0050] The present invention has the following effects:
[0051] As described above, a small ink chamber (L: 30 mm, H: 360 μm and B: 70 μm) is provided between integral substrate 1 and lid member 2 . In aforesaid ink chamber, apertures are only provided on the ink feeding portion side and ink emission portion side. In addition, aforesaid apertures are so small as to be (H: 360 μm×70 μm). In spite of this, due to the resin layer forming step of the present invention, para-xylylene radical which occurred due to heat decomposition invades from aforesaid small apertures, and adheres on an ink chamber having depth of 30 mm. Simultaneously with this, due to vapor phase polymerization, the poly-para-xylylene resin layer having high molecular weight can be formed in the small ink chamber.
[0052] According to a conventional deposition method, a layer can be formed only on an exposed surface. Therefore, when a layer is formed on electrode layer 3 formed on a groove of substrate 1 , it was necessary to conduct deposition while the groove of substrate was exposed prior to an adhesive step with lid member 2 .
[0053] On the contrary, in the case of chemical deposition in which a resin layer, composed of poly-para-xylylene or its derivatives, is formed, even after substrate 1 and lid member 2 are integralized in the adhesive step, a resin layer can be formed on the inner wall inside the ink chamber through extremely small apertures.
[0054] According to an experiment by the present inventors, it was confirmed that a layer could be formed in the inner wall of chamber in which the depth was 2-50 mm, through an aperture on both end of the chamber of 1-1000 μm 2 .
[0055] As described, prior to the resin layer forming step, substrate 1 and lid member 2 can be integralized in the adhesive step. the adhesive surface of substrate 1 and the adhesive surface of lid member 2 can be fixed with a sufficient adhesive force so that ink can be emitted with a relatively low impressing voltage.
[0056] According to the present invention, a chamber is formed by integralizing a piezoelectric ceramic substrate having a vibration wall having an electrode layer and a lid member forming a fixed wall. Following this, by means of a vapor phase polymerization method, a resin layer composed of poly-para-xylylene or its derivative is formed for forming an ink path. Thus, an ink jet head excellent in terms of emission performance of water-based ink for a long period and a life. | A method of producing an ink-jet head having an ink chamber composed of at least a first wall member and a second wall member, wherein the first wall member includes a vibrating wall made of a piezoelectric ceramic on which an electrode layer is formed and the second wall member forms a fixed wall, comprising steps of: (1) combining the first wall member and the second wall member into one body so that the ink chamber is formed between the first wall member and the second wall member and the electrode layer is located inside the ink chamber; and (2) subjecting the combined one body of the first wall member and the second wall member to gas phase polymerization so that a resin layer of poly-para xylylene or its derivative is formed on the electrode layer in the ink chamber. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to a connector for fast connection of a mating tube to a fluid assembly, and, more particularly, to a device for providing a redundant clip for use with a quick connector having a primary connector component.
Quick connectors are known and have been widely used in the art and are used in fluid carrying assemblies such as automobile assembly plants and service centers. More recently, these connectors have been provided in the form of a unitary connector body which is joined with the male end of a mating tube. The recent connectors use an internal connector component which receives an upset bead on the male tube member to retain the male tube member within the unitary connector. These recent connectors utilize either a pair of O-rings or a one-piece seal with multiple ribs to seal the male member with respect to the unitary connector. The O-rings or ribs surround the center male end of the mating tube. These connectors have the disadvantage that if an accidental disconnection occurs, fluid can flow out of the connector body. These connectors have the further disadvantage that an indication as to whether a proper lock connection has been provided is not readily apparent.
U.S. Pat. No. 5,069,424 issued to Robert Dennany and Ken Randall and assigned to the assignee of the present invention, ITT Corporation, address the above problems that occur with single clips. The '424 patent disclosed a secondary retaining clip which had means for engaging a portion of the housing to releasably lock the secondary retaining clip to the housing. This retaining clip had resilient finger portions which were received within annular grooves in the unitary connector housing. The retaining clip has an inwardly directed portion which will engage the bead of the male tube if it is attempted to be removed. The secondary clip can only be connected if the male tube is properly received within the unitary connector.
One disadvantage of the '424 connector is that it requires an annular groove to be formed in the housing. Further, the secondary clip would likely require one or more tools in order to remove the resilient fingers from the annular groove formed in the housing.
SUMMARY OF THE INVENTION
The present invention provides an improved secondary or redundant clip for connecting a male tube to a unitary connector or connector housing. In the disclosed embodiment the male tube includes an upset portion and the connector housing has a recess for receiving the male tube and the upset. The connector housing has an exterior surface that is contoured to define at least a first section and second section, with the second section having reduced diameter. As further disclosed in the preferred embodiment, the connector housing includes a primary connector assembly for primarily retaining the tube in the housing.
The clip of the present invention is generally L-shaped and includes a retaining head, a body portion and a base portion. The retaining head is adapted to engage the upset of the male tube when the male tube is positioned within the recess of the connector housing. The retaining head is defined by a pair of spaced fingers ending in engaging ears. The engaging ears extend inwardly with respect to each other to form a reduced space between the fingers. The reduced space has a width which is less that the diameter of the male tube so that the ears have to be biased outwardly to receive the male tube.
The retaining head extends outwardly from the body portion at an angle with respect to the body portion and is spaced from the body portion by a distance slightly greater that the distance between the exterior surface of the connector housing and the recess.
The body portion is defined by a channel having a base and sidewalls. The sidewalls extend generally perpendicular to the base. In the preferred embodiment, the sidewalls have an edge that is contoured to generally mate with the exterior contour of the connector housing.
The base portion is defined by spaced leg members which extend outwardly from the body portion and are preferably joined at their ends. The leg members are spaced apart a distance which is slightly less than the outer diameter of the reduced section of the connector housing so that they bias against the reduced section. In the preferred embodiment, the leg members have first and second spaced detents to receive the reduced section. These detents correspond to the latched and unlatched positions of the clip. Each of the leg members includes a top edge that defines a cam surface for engaging the bottom of the reduced surface to facilitate the insertion of the retaining head into the recess of the connector housing and for locking the clip in place. The cam and leg members act as a lever giving substantial mechanical advantage to insertion of the head portion. The cam surface ends in a locking surface which is adjacent the body portion and is adapted to engage the bottom of the reduced surface when the clip is in the latched position. This engagement provides the needed retention force to retain the tube in the connector.
In use, the clip is mounted to the connector housing by the base member. It is intended that the clip always remain attached to the connector housing and in particular to the reduced section. In the disclosed embodiment, the clip is mounted onto the reduced section by separating the legs and placing the reduced section between them and then snapping the free ends of the legs together. The legs are biased against the reduced section of the connector housing and can slide with respect to the housing.
To use the clip, the first step in locking the male tube with respect to the connector housing is to rotate the clip against the male tube. With slight pressure against the base of the body member, just behind the retaining head, the engaging ears can be forced apart and about tube. Rotation of the clip is facilitated by the interaction of the detent with respect to the reduced section which, in combination, acts as a pivot point. The edge of the base member abuts the base of the second section when the ears are clipped about the tube.
By next applying pressure to the base of the body portion of the clip just behind the base member, the legs slide along the reduced section and the cam surface is caused to cam against the base of the reduced section. It should be appreciated that the ears are biased against the tube and form a second pivot point with respect to the tube. As pressure is applied to the body portion, the ears simultaneously pivot and slide with respect to the tube in the direction of the connector housing as the cam surface is cammed against the base of the reduced section.
After rotation of the clip, the second detent on the legs of the clip engages the reduced section and the retaining head is securely inserted into the connector housing to retain the tube therein. The top edge of the legs abuts the base in this position. In this way, the retention force of the clip or the pull-out strength is determined by the shear strength of the body member at the joinder of the head and base member.
To disconnect the tube from the connector housing, the base member is slid away from the connector housing. The edge and cam abut the base and the retaining head is slid out of the connector housing. A surface on the engaging ears can be pushed by the user to spread open the fingers to release the retaining head from the tube. The clip is then in the unlocked position.
As should be appreciated, the clip can be locked and unlocked without the need for tools. Additionally, the clip remains on the housing so that it is not misplaced and so that it is much easier to ship with the housing. The clip is an exterior clip which is highly reliable and gives a clear indication when the clip is properly fastened. The clip is only properly fastened when the body member of the clip is adjacent and parallel to the body housing, in the preferred embodiment, the mating contour of the inside edge of the body member of the clip with the exterior surface of the housing make a sure indication of proper alignment. It also provides the advantage of a redundant or a secondary clip to ensure against improper installation of the primary clip. A still further advantage is that the clip does not require modification of a standard connector housing, the clip is merely snapped over a reduced portion of the standard housing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present invention attached to a tube connector.
FIG. 2 is a side view of the present invention in the unlocked position.
FIG. 3 is a side view of the present invention as it is rotated to or from the locked position.
FIG. 4 is a side view of the present invention in the camming position.
FIG. 5 is a side view of the present invention in the locked position.
FIG. 6 is a partial view of the ends of the base member of the clip of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, the redundant clip of the present invention is shown generally at 10. In the preferred embodiment, the clip is made from 301 stainless steel, 3/4 hard with a thickness of 0.032 to 0.036 inches. The clip is used to retain a tube 12 within a connector housing 16. As should be appreciated, the tube 16 and the connector housing 12 are standard quick connects. The tube 12 includes an upset 14 and in the disclosed embodiment the connector housing 16 includes locking fingers 18 mounted in the interior 20 of the housing. The fingers 18 are adapted to retain the tube 12 within the female housing 16. The connector housing includes a top hat 22 and a bearing surface 24 for maintaining the alignment of the tube 12 within connector housing 16. O-rings 26 are provided to seal the male tube 12 with respect to the connector housing 16.
The exterior of connector housing 16 is contoured and has an exterior surface defined by a first section 28, a reduced diameter second section 30 which is separated from section 28 by a base 32. A further reduced diameter third section 34 which is separated from section 30 by a base 36. A still further reduced section 38 which is separated by a base 41. Section 38 is adapted to be inserted into a hose member.
With reference to FIG. 1, the unlocked or shipping position of connector 10 is illustrated. FIG. 4 illustrates the locked position of connector 10. FIGS. 2 and 3 illustrate the primary positions of the connector 10 as it is moved from the unlocked to the locked positions.
Broadly, the redundant quick connector 10 of the present invention is generally L-shaped and has a retaining head 40, a body member 42 and a base member 44. The retaining head 40 is adapted to be inserted into the connector housing 16 and locked against the upset 14 of the tube 12. The body member 42 joins the retaining head 40 and the base member 44 and is adapted to adjoin the connector housing 16 and to provide retention support to the clip 10. The base member 44 interconnects the clip to the connector housing 16 and provides a camming surface for facilitating the locking of the clip 10. In the preferred embodiment, the clip 10 is mounted upon the connector housing 16 and is not intended to be removed from the connector housing 16.
The retaining head 40 is adapted to engage the upset 14 of tube 12. The retaining head 40 is generally hook shaped and is defined by a pair of spaced fingers 46 which end in engaging ears 48. As disclosed, the spaced fingers have a rounded end portion 50 for engaging the upset 14. The engaging ears 48 extend inwardly to form a reduced space between the finger 46 and then are bent outwardly to form a surface 52 to allow a user to force the ears 48 from about the tube 12 when the clip 10 is to be locked. The reduced space between the fingers 46 has a width which is less that the diameter of the tube 12. In this way, the ears 46 can be biased outwardly to receive the tube 12. This is illustrated in FIG. 2.
The body portion 42 is defined by a channel having a base 54 and sidewalls 56. The sidewalls 56 extend generally perpendicular to base 54 and end in an edge 58. In the disclosed embodiment, the edge 58 is contoured to have the same general shape as and to generally mate with the exterior contour of connector housing 16. The channel shape of body portion 42 adds strength to the clip and provides tube pull-off retention in excess of 100 LBS force.
As can be seen, the retaining head 40 extends outwardly from the body portion 42 at an angle with respect to the body portion 42. The retaining head 40 is spaced from the body portion 42 by a distance which is slightly greater than the width of the overturned edge 60 of the connector housing 16. This space allows the retaining head 40 to be inserted into the connector housing 16.
The base portion 44 includes spaced leg members 62 which extend outwardly from body portion 42 and are joined at their ends 64. As shown in FIG. 6, the ends 64 are bent over to form mating lips 66 that can be easily snapped together and easily released. Legs 62 are normally biased outwardly.
Leg members 64 are preferably elongated relatively thin members having sides 68 and top and bottom edges 70. The sides 68 are spaced apart a distance which is slightly less than the outer diameter of the third section 34 of connector housing 16. Because the distance is less, legs 64 are biased against third section 34, but are free to slide with respect to section 34. Each of the sides 66 have outwardly bowed sections or detents 72 for receipt of the third section 34 as leg members 64 are slid along the third section 34. Detent 72 corresponds to the unlocked position, see FIG. 1, and detent 74 corresponds to the locked position, see FIG. 4, of clip 10.
The top edge 70 of each leg member 62 defines a cam surface shown generally at 74. The cam surface 74 interconnects the detents 72 and 73, and functions to pull the retaining head 40 into the connector housing 16 to engage the upset 14. Cam surface 74 engages the base 36 of the second section 30. In the embodiment illustrated in FIG. 1, the third section 34 has a guide or retaining surface 76 to keep the leg members 62 adjacent to the base 36. It should be understood that some connectors do not have feature 76. It is not necessary to the proper functioning of the clip 10.
In use, the clip 10 is initially in the position illustrated in FIG. 1. It is intended that the clip 10 always remain attached to the connector housing 16 and in particular to third section 34. In the disclosed embodiment, clip 10 is mounted onto the third section 34 by separating the legs 62 and placing the third section 34 between them and then snapping the ends 64 together. As stated above, the legs 62 bias against section 34.
With reference to FIG. 2, the first step in locking the tube 12 with respect to the connector housing 16 is to rotate the clip 10 against the tube 12. With slight pressure against base 54 of body member 42, just behind head 40, the engaging ears 48 can be forced apart and about tube 12. The rotation of clip 10 is facilitated by the interaction of detent 72 with respect to the third section 34 which forms a pivot point. As can be seen, the edge 74 of preferably abutting the base 36 of second section 30.
Referring now to FIG. 3, the camming action of edge 74 is illustrated. With pressure applied to base 54 of body member 42 just behind the base member 44, the legs are caused to slide along the third section 34 and the cam surface 74 is caused to cam against the base 36. It should be appreciated that the ears 48 are biased against the tube 12 and form a pivot point with respect to member 12. As pressure is applied, the ears 48 pivot and will slide with respect to the tube 12 in the direction of connector housing 16 as the cam surface 74 is cammed against base 36.
With reference to FIG. 4, the clip 10 is in the locked position. In this position, the detent 73 is engaging the third section 34 and the retaining head 40 is inserted into the connector housing to retain the tube 12 therein. The top edge 70 of legs 62 is abutting the base 36. In this way, the retention force of the clip or the pull-out strength is determined by the shear strength of the body member 42 at the intersection of the head 40 and base member 44. As should be appreciated, the tip 50 of ears 48 is generally aligned with the line of contact of the detent 72 and the base member 36 to reduce the bending moment in the body member 42. Additionally, the edge 58 is illustrated as closely conforming to the outer contour of the connector housing 16.
To disconnect the tube 12 from the connector housing 16, the base member is slid away from the connector housing 16 to the position illustrated in FIG. 3. As above, the edge 70 and cam 74 abut the base 36 and the retaining head 40 is slid out of the connector housing 16 and pivots about the tube 12. In the position illustrated in FIG. 3, a user can push against the surface 52 of engaging ears 48 to spread the fingers to release the retaining head 40 from the tube 12. The clip 10 pivots about detent 72 to the position illustrated in FIGS. 1 and 2.
As should be appreciated, the clip 10 can be locked and unlocked without the need for tools. What has been disclosed, is a quick connector which provides a redundant clip having superior pull-off strength which is easy to manufacture and easy to use and that it does not require the use of tools. Additionally, the clip provides visual indication of a properly locked assembly and precludes outflow of fluid if there is improper connection of the primary connector, and which overcomes the disadvantages of the prior art. The form of the invention illustrated and described herein is a preferred embodiment of these teachings. It is shown as an illustration of the inventive concepts, however, rather than by way of limitation, and it is pointed out that various modifications and alterations may be made within the scope of the appended claims. | A quick connect connector for fast connection of fluid carrying assemblies such as a mating tube and a fluid unit. The connector includes a connector body which houses the connector components and accepts a redundant clip which is adapted to engage an upset bead of the male tube. The redundant clip is generally L-shaped and include a retaining head which is inserted into the connector body and is adapted to engage the upset bead, a body portion which extends along the side of the connector body and in the preferred embodiment is contoured to mate with the connector body and a base member which includes a camming edge and pivot points for facilitating the insertion of the retainer head into the connector body. | 8 |
FIELD OF THE INVENTION
[0001] This invention relates generally to wireless headsets and more specifically to a transceiver/receiver headset with an adjustable in-ear friction retainer sheath.
BACKGROUND OF THE INVENTION
[0002] Wireless headsets provide greater convenience and safety to the users of such devices as cell phones, by allowing the user partially or completely hands free operation of the cell phone. Such headsets normally comprise some sort of head band or ear clip to retain the headset in the proper position, a microphone located near the mouth, and such wireless equipment as is necessary to communicate with a base unit located at or on the cell phone or similar device.
[0003] However, the comfort and convenience of the wireless headset may be reduced by the method of maintaining the headset in position on the user's head. Head bands which cross over the top of the head quickly become uncomfortable and may slip out of position. Ear clips also suffer from the problem of discomfort. Various types of headsets exist which illustrate these difficulties.
[0004] U.S. Pat. No. 4,882,745 issued Nov. 21, 1989 to Silver for “CORDLESS HEADSET TELEPHONE” shows one early telephone headset in the context of a conventional land-line telephone. The headset disclosed has a large ear piece, telescoping antennas in both base unit and headset, and a cross section so large as to include a keypad on the headset portion of the device. The headset also includes on/off switches and a manual volume control. The size of this headset is notable.
[0005] U.S. Pat. No. 5,590,417 issued Dec. 31, 1996 to Rydbeck for “RADIOTELEPHONE APPARATUS INCLUDING A WIRELESS HEADSET” teaches a headset in which recharging is accomplished when the headset is attached to the base transceiver unit. Two embodiments are taught in both of which manual control of headset output volume is accomplished manually at the base transceiver unit. The wired version of the unit is small but the wireless version appears to be almost as large as the original cell phone, somewhat defeating the intent of the device.
[0006] U.S. Pat. No. 5,790,684 issued Aug. 4, 1988 to Niino et al for “TRANSMITTER/RECEIVING APPARATUS FOR USE IN TELECOMMUNICATIONS” teaches a multiplicity of earphones (connected by wire 17 and similar wires) which are wired to a cell phone. It is small, wired, and does not appear to provide any means of adapting to the ear sizes of different users or assuring comfortable and sanitary operation.
[0007] U.S. Pat. No. 5,933,506 issued Aug. 3, 1999 to Aoki et al for “TRANSMITTER-RECEIVER HAVING EARPIECE TYPE ACOUSTIC TRANSDUCING PART” teaches a non-wireless headset with an earpiece connected thereto. It is small, wired, and does not appear to provide any means of adapting to the ear sizes of different users or assuring comfortable and sanitary operation.
[0008] U.S. Pat. No. 6,078,825 issued Jun. 20, 2000 to Hahn et al. for “MODULAR WIRELESS HEADSET SYSTEM FOR HANDS FREE TALKING” and U.S. Pat. No. 6,230,029 B1 issued May 8, 2001 to Hahn et al. for “MODULAR WIRELESS HEADSET SYSTEM” disclose a headset having battery contacts used to charge the removable battery pack module. These patents also teach that the headset have manual on/off, channel and volume controls. The unit is nicely streamlined but uses a bulky earclip and a long microphone tube which together probably render it somewhat heavy and uncomfortable.
[0009] U.S. Pat. No. 6,228,020 issued May 8, 2001 to Juneau et al for “COMPLIANT HEARING AID” comes from the technical field of hearing aid design, not wireless headset design. It teaches a hearing aid having a soft polymeric body covering the part inserted into the ear. This provides comfort and convenience to the sole owner, however, sharing of hearing aids is extremely uncommon, and thus no provision is made for adjusting the size of the unit to different users, nor for sanitation, nor for replacement of the body when it is worn out.
[0010] U.S. Pat. No. 6,415,034 issued Jul. 2, 2002 to Hietanen for “EARPHONE UNIT AND A TERMINAL DEVICE” discloses a small unit which is mounted in the external ear (for the wireless version of FIG. 12) by means of a lug in the ear canal. It does not appear to provide any means of adapting to the ear sizes of different users or assuring comfortable and sanitary operation.
[0011] Finally, US Patent Application Publication No. U.S. 2001/0016506 A1 published Aug. 23, 2001 in the name of Son et al. and entitled “WIRELESS HANDS-FREE SYSTEM OF CELLULAR PHONE” teaches a battery operated hands free headset having a battery saving feature described in paragraph 0014. No indication of any means of charging of the battery is present in the publication, and as specified in the final phrase of paragraph 0013, a switch on the headset is operated by the user. The device is smaller than most of the prior art devices but still appears to be larger than the user's ear, to which it is clipped by means of a clip 303 .
SUMMARY OF THE INVENTION
[0012] General Summary
[0013] While previous wireless headsets teach a retainer for the device that may be a headband or ear clip, the present invention teaches a retainer in the form of a removable compliant polymer sheath.
[0014] The present invention teaches a wireless headset reduced in size to an earpiece, in which the comfort and sanitation of the user and the life span of the device may in increased by providing a replaceable compliant polymer sheath for the sound tube which is inserted into the ear canal: friction between the ear canal and the sheath retains the wireless headset in the ear canal. In alternative embodiments, the sheath and ear canal may mechanically cooperate to retain the wireless headset in the ear canal. The sheath may be easily removed and replaced so as to adapt the length and diameter of the device for the needs and comfort of different users. In addition, the replaceable polymer sheath allows safe and sanitary use of one wireless device by more than one user. In addition, polymers are notorious for becoming oxidized and then hard and brittle, however the device of the invention need not be refurbished for this reason since the compliant polymer sheath may be easily removed and replaced whenever required.
[0015] Summary in Reference to claims
[0016] It is therefore one aspect, advantage, objective and embodiment of the present invention to provide a retainer for wireless headsets having a generally cylindrical sound tube for insertion into a user's ear canal, the sound tube having a generally cylindrical configuration; the retainer comprising: a generally cylindrical sheath having an exterior sheath configuration and an interior sheath configuration; the interior sheath configuration being approximately the same as such sound tube configuration, whereby such sheath may be easily disposed onto and removed from such sound tube; the exterior sheath configuration being dimensioned and configured for comfortable use and suspension of the wireless headset by means of forces between such ear canal and the sheath; the sheath further having at least one aperture allowing sound transmission between such sound tube and such ear canal.
[0017] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer wherein the sheath is a compliant polymer material.
[0018] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer wherein the sheath is one member of the group consisting of: silicon based materials, silicon compounds, elastomeric materials, flexible materials, rubbers, gums, gels, soft silicon-like materials, liquids, liquids encased in a compliant shell, and combinations thereof.
[0019] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer wherein the sheath is one member of the group consisting of: mixtures of multiple compounds, mixtures of multiple polymers, polyphase foams, open cell foams, closed cell foams, material intrusions, material cells, liquids, and combinations thereof.
[0020] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer further comprising: an open end; and a circumferential ridge of material about the open end.
[0021] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer wherein the forces between the sheath and such ear canal are frictional forces.
[0022] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer wherein the interior sheath configuration is dimensioned and configured such that the sheath is retained upon the sound tube by means of forces between the sheath and the sound tube.
[0023] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer of claim 7, wherein the forces between the sheath and the sound tube are frictional forces.
[0024] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer of claim 7, wherein the sheath and the sound tube mechanically cooperate to retain the sheath upon the sound tube.
[0025] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a retainer of claim 3, wherein the headset body further comprises: a circumferential groove about the sound tube, and wherein the circumferential ridge of material about the open end of the sheath mechanically cooperates with the groove to retain the sheath upon the sound tube.
[0026] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide an improved wireless headset having a headset body wherein the improvement comprises: a sound tube; a removable sheath disposed on the sound tube, the sheath having at least one aperture therethrough, the sheath begin dimensioned and configured such that when the sound tube is inserted into the ear canal of a user, the wireless headset is retained on the user's head by the forces between the sound tube and the ear canal.
[0027] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide an improved wireless headset further comprising: at least one aperture in the sound tube, the aperture in the sheath being aligned with the aperture in the sound tube; and a mini-speaker arranged so as to pass sound from the mini-speaker out of the headset body through the aperture in the sound tube and the aperture in the sheath.
[0028] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide an improved wireless headset further comprising: a removable and replaceable antenna casing.
[0029] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide an improved wireless headset further comprising one member selected from the group consisting of: a transceiver, a microphone, a receiver, an antenna, a battery and combinations thereof.
[0030] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide an improved wireless headset wherein the antenna further comprises an antenna casing incorporating a microphone tube extending towards the mouth of the user.
[0031] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a wireless headset comprising: a headset body; a sound tube projecting from the headset body and having an aperture; a mini-speaker disposed within the headset body so as to pass sound from the mini-speaker out of the headset body through the aperture; a removable sheath disposed on the sound tube.
[0032] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a wireless headset wherein the removable sheath further comprises one member selected from the group consisting of: a compliant polymer material, silicon based materials, silicon compounds, elastomeric materials, flexible materials, rubbers, gums, gels, soft silicon-like materials, liquids, liquids encased in a compliant shell, and combinations thereof.
[0033] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a wireless headset further comprising one member selected from the group consisting of: a microphone, a transceiver, a receiver, an antenna, a battery and combinations thereof.
[0034] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a wireless headset further comprising: a battery; and a battery cap having knurls allowing easier removal and replacement of the battery cap, thereby allowing easier removal and replacement of the battery.
[0035] It is therefore one more aspect, advantage, objective and embodiment of the present invention to provide a wireless headset further comprising: an antenna casing having an antenna therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] [0036]FIG. 1 is a side view of a wireless headset embodying the sheath of the preferred embodiment of the invention.
[0037] [0037]FIG. 2 is an end view of the wireless headset of the first embodiment shown in FIG. 1.
[0038] [0038]FIG. 3 is a bottom view of the wireless headset of the first embodiment shown in FIG. 1.
[0039] [0039]FIG. 4 is an exploded perspective view of the wireless headset of the first embodiment shown in FIG. 1.
[0040] [0040]FIG. 5 is a perspective view of the sheath according to a second embodiment of the invention.
[0041] [0041]FIG. 6 a bottom view of a third embodiment of the invention.
[0042] [0042]FIG. 7 is a perspective view of a fourth embodiment of the invention.
DETAILED DESCRIPTION
[0043] [0043]FIG. 1 is a side view of a wireless headset embodying the sheath of the preferred embodiment of the invention. FIG. 2 is an end view of the wireless headset of the first embodiment shown in FIG. 1. FIG. 3 is a bottom view of the wireless headset of the first embodiment shown in FIG. 1. As seen in these three figures, headset 2 has sheath 4 which fits into the ear canal (not pictured) of a user. The ear canal is any and all of that small cavity leading from the outer ear to the inner ear. Friction between the interior of sheath 4 and the headset body 6 retains sheath 4 in place on wireless headset 2 , friction between the exterior of sheath 4 and the ear canal retains headset body 6 of wireless headset 2 in place. As used herein, a sheath is any removable covering used to cover a projection into the ear canal, regardless of the shapes of the ear canal or projection. While sheath 4 is a compliant polymer material, headset body 6 may be a relatively more rigid construction such as plastic, metal or another more rigid polymer. In general, any such projection into the ear canal will be referred to herein as a sound tube: the sound tube configuration may vary a good deal in size, shape, form and substance: it may be entirely rigid, semi-rigid, it may be cylindrical, generally cylindrical, irregular, fitted to the ear or another shape. The sound tube will usually have therein either a speaker or an aperture, grill, mesh or other device to allow sound to pass from a mini-speaker in the sound tube or wireless headset body 6 to the ear canal of the user, and/or pass the other direction. The aperture in the sound tube is aligned with the aperture in the sheath when the sheath is disposed upon the sound tube.
[0044] [0044]FIG. 4 is an exploded perspective view of the wireless headset of the first embodiment shown in FIG. 1. In the best mode now contemplated and presently preferred embodiment of the invention, by means of sheath 4 of the present invention, the wireless headset may miniaturized greatly as no headband or ear clip retainers are necessary. Sheath 4 will suffice to comfortably hold in place the super miniaturized headset for long periods of time, unlike large headsets having such forms of retainers. Unlike prior art ear pieces which rely on friction directly between the sound tube and the ear canal, sheath 4 of the wireless headset of the present invention maintains an adequate comfort level. Unlike any known combination of patents taken from related and unrelated technologies, the invention has a removable and replaceable sheath over a permanent, more rigid body (in this case, the sound tube).
[0045] The wireless headset of the preferred embodiment of the invention has an upper body 8 , a lower body 10 , and circuitry 12 disposed in between. In the preferred embodiment, circuitry 12 comprises a printed circuit board with silicon electronic components thereon. Battery 14 provides electrical power, battery 14 may be changed by removing cap 16 (note that while battery 14 is below upper body 8 in FIG. 4, it may be above or co-elevation therewith, even in the preferred embodiment pictured).
[0046] The wireless headset may include either a receiver or a transceiver allowing both reception and transmission. In receiver embodiments, it may be utilized to carry an audio signal in a passive mode, for example a broadcast radio signal or a signal received from a broadcast unit which itself receives the audio signal from a source such as a television set or radio. In transceiver embodiments, the wireless headset may be used in conjunction with a cell phone or similar device to provide true hands free operation without a wire, a bulky headset having an ear clip or head band, and yet with increased comfort and sanitary benefits to the wearer.
[0047] Speaker housing 18 contains mini-speaker 20 . One advantage of the method of the present invention is that mini-speaker 20 may be sized, selected and arranged so as to minimize power drain upon battery 14 . That is, use of sheath 4 , the wireless headset of the present invention may be maintained in very close position to the ear drum of the user, thus minimizing drive current needed for mini-speaker 20 . In addition, the configuration of speaker housing 18 includes sound tube 22 , which actually projects into the ear canal of the wearer, directing sound precisely at the ear drum of the user and potentially bringing mini-speaker 20 even closer to the ear drum in alternative embodiments. Thus, a smaller speaker, smaller battery and smaller unit are permitted by the invention, thus furthering the convenience of the user. Mini-speaker 20 may be a peizo-electric device, a button speaker, or another type of speaker.
[0048] Sheath 4 is generally cylindrical in the drawings and preferred embodiment, having a slightly conical exterior sheath configuration. In alternative embodiments, sheath 4 may be more sharply conical in exterior sheath configuration, may be a true cylinder, may be an ogive shape, a rounded shape, parabolic, elliptical, other regular shapes, or it may be an irregular shape or have an exterior sheath configuration specifically designed for the human ear or even for the ear of one or specific individuals. As used herein, the words exterior sheath configuration encompass any shape of the exterior of the sheath. The exterior sheath configuration is dimensioned and configured for (that is, is size, shape, form and substance are suitable for) comfortable use and suspension of the wireless headset by means of frictional forces between ear canal and sheath. Thus, placed into the ear, sheath 4 generates sufficient frictional forces to hold the tiny weight of the wireless headset in proper place.
[0049] [0049]FIG. 4 also displays the sheath of the preferred embodiment of the invention. In the preferred embodiment, sheath 4 furthermore narrows at one end to a small aperture (aperture 26 of FIG. 4). The narrowing in the preferred embodiment takes the form of bevel 34 , which terminates in aperture 26 . This end is proximate the ear drum of the user and is inserted into the user's ear. At the distal end, sheath 4 has an optional circumferential ridge 32 which adds strength to sheath 4 , aids manipulation of sheath 4 by human fingers, and may help to maintain sheath 4 on the sound tube of wireless headset 2 . The size of aperture 26 allow sound transmission between such sound tube and such ear canal. Aperture 26 may be replaced by a pattern of smaller apertures, an aperture having a screen or other members extending across it, and so on.
[0050] Sheath 4 is retained by friction on the sound tube in the presently preferred embodiment, however, in other embodiments other methods of retention are possible. Actual mechanical cooperation is a strong alternative embodiment. For example, an alternative circumferential ridge may extend inwardly towards the longitudinal axis (long axis) of sheath 4 , thus presenting a small detente on the inside of sheath 4 . In such alternative embodiments, the sound tube 22 may have thereon a circumferential groove into which the circumferential ridge may fit, providing mechanical cooperation to hold sheath 4 onto sound tube 22 . Sheath 4 and sound tube 22 may also be equipped with snaps, belts, fasteners, bumps or other devices for holding sheath 4 onto sound tube 22 .
[0051] Sheath 4 may be made of a compliant polymer or silicon based material. In addition, may equivalent materials may be employed. Any elastomeric, flexible, material may be used: in addition to polymers and silicon based materials, silicon compounds, rubbers, gums, other materials such as gels, soft silicon-like materials, liquids, liquids encased in a compliant shell, and similar materials. In the preferred embodiment, the silicon compound or polymer is a single phase and a single compound/polymer. In alternative embodiments, mixtures of compounds may be used: mixtures of two or more compounds or polymers (including copolymers, multi-polymers). Such compounds and polymers need not be uniphase bodies but may be polyphase foams, either or open or closed cell foams, or may include other material intrusions or cells such as water or other liquids, other solids which enhance material properties by adding or reducing stiffness, plastic memory, ductility and so on.
[0052] The construction of sheath 4 is subject to numerous alternatives, equivalents and substitutions within the scope of the invention as claimed herein.
[0053] While frictional forces may be implicated in retaining the wireless headset in the ear of a user in the presently preferred embodiment, in other embodiments, the sheath may be configured so that actual mechanical cooperation between the ear canal and the sheath may serve the same purpose, that is, the convolutions of the ear canal may cooperate with the exterior sheath configuration.
[0054] [0054]FIG. 5 is a perspective view of the sheath according to a second embodiment of the invention. Sheath 4 has sheath body 24 , interior sheath configuration 30 , and circumferential ridge 28 about the open end of sheath body 24 . In this embodiment, circumferential ridge 28 is used to aid retention of sheath 4 on sound tube 22 by increasing frictional forces therebetween. In this embodiment, sheath 4 is provided separately from a wireless headset. Sheath 4 of this embodiment may be offered to owners of devices such as the headset which have a sound tube which is inserted into the ear canal.
[0055] Sheath 4 may be used as a retrofit to increase the comfort of devices not having such a sheath, or it may be used as a replacement when an original sheath wears out and must be replaced. Polymers, particularly relatively flexible polymers, are prone to becoming oxidized and thus replacement will increase the life span of wireless headsets and the like.
[0056] However, there are additional very significant advantages to removable and replaceable sheath 4 . A device using such a sheath may be used by more than one individual without the unpleasant and unsanitary necessity of inserting the same contact surface into the ears of different individuals. A first user may use a first sheath, while a second user might use a second sheath when the device must be exchanged from ear to ear. By this means there is no chance of transmission of biological materials from ear to ear, and potential squeamishness of multiple users is averted.
[0057] Another important advantage relates to comfort. Different people have differing ear canals, meaning that a device comfortable in one person's ear canal might not be comfortably suspended in the ear canal of another. If the second user's ear canal is smaller than the size most comfortably used with a first sheath, the wireless or other device might cause pain when inserted into the ear. If the later users ear canal is larger, however, the fit will be loose; perhaps the device might fall out for this reason. Ear canals also vary in configuration, meaning that sheaths may be provided according to the second embodiment of the invention in different exterior sheath configurations. By the term configuration as used herein, the concepts of shape, size, modulus of elasticity, Young's modulus, flexibility, hardness, size of apertures and so on are all included.
[0058] Similarly, interior sheath configuration 30 may vary in order to fit the sound tube upon which it will be placed. Active tense placement of sheath 4 onto a sound tube, and passive tense location of sheath 4 on a sound tube, are both referred to herein as “disposal on the sound tube”, and actively taking sheath 4 off of the sound tube, and sheath 4 being found off of a sound tube, are referred to as “removal from sound tube 4 ”.
[0059] [0059]FIG. 6 a bottom view of a third embodiment of the invention. In this embodiment, an optional antenna casing 36 is employed. By this means, radio reception of the wireless headset device, and transmission to a base station in embodiments having such, both may be dramatically improved. Antenna casing 36 may also served double duty as an optional microphone tube extending towards the mouth of the user and thus providing better audio reception of the voice of the user.
[0060] Antenna casing 36 may be a removable and replaceable device which the user may remove and replace as desired: in such alternative embodiments, the device may be used either with the antenna casing 36 on the device, or the wireless headset device may be used without the antenna casing 36 .
[0061] [0061]FIG. 7 is a perspective view of a fourth embodiment of the invention. In this embodiment, the headset case 6 of device 2 may have grips 38 allowing easier manipulation by the user.
[0062] This embodiment may also have cap 16 provided with knurl 40 which aids the user in removing/replacing cap 16 when replacing battery 14 (not visible in FIG. 7). This embodiment may also have cap 16 provided with indentation 42 which aid in retention of battery 14 inside of headset body 6 . A battery cap having knurls allows easier removal and replacement of the battery cap, thereby allowing easier removal and replacement of the battery.
EXAMPLE 1
[0063] A wireless headset in accordance with the present invention was constructed having a sheath according to the preferred embodiment of the invention. The headset contained a circuit board having integrated chipsets and support components offering transmission and reception of radio waves. An ancillary base unit allowed the headset to cooperate with a telephone or similar device to provide hands free operation. By means of the present invention, the device has no ear clip, no head band and no retainer other than the sheath of the present invention, and thus the wireless headset is substantially miniaturized over products presently on the market. The sheath was narrower at the proximal end (inserted into the ear canal) than at the distal end. The end of the sheath is chamfered for further comfort and ease of use, with an aperture allowing passage of sound from the body of the wireless device to the ear canal of the user.
[0064] The body portions of the wireless device are a hard plastic material, but may be constructed of metal or other relatively hard materials.
[0065] The sheath is composed of a compliant silicon based compound or polymer.
[0066] In use, the sound tube, sheath disposed thereon, is inserted into one ear of the user. A microphone at the lower end of the device picks up the user's voice for transmission to a base unit connected to a cell phone, ordinary phone or equivalent device. A receiver in turn picks up transmissions from the base unit and converts them to audio using a mini-speaker located at the base of the sound tube. Sound from the mini-speaker travels from the sound tube, through the sound tube aperture and sheath aperture and thus to the ear canal of the user.
[0067] Should another user desire to use the device, the user may remove it from their ear canal, remove the polymer sheath, and hand it to the other user, who may then use their own polymer sheath to put it on. Polymer sheaths of different sizes than that listed above may be provided for different individuals.
[0068] The disclosure is provided to allow practice of the invention by those skilled in the art without undue experimentation, including the best mode presently contemplated and the presently preferred embodiment. Nothing in this disclosure is to be taken to limit the scope of the invention, which is susceptible to numerous alterations, equivalents and substitutions without departing from the scope and spirit of the invention. The scope of the invention is to be understood from the appended claims. | The present invention teaches a retainer in the form of a removable compliant polymer sheath. The present invention further teaches a wireless headset reduced in size to an earpiece, in which the comfort and sanitation of the user and the life span of the device may in increased by providing a replaceable compliant polymer sheath for the sound tube which is inserted into the ear canal: friction between the ear canal and the sheath retains the wireless headset in the ear canal. In alternative embodiments, the sheath and ear canal may mechanically cooperate to retain the wireless headset in the ear canal. The sheath may be easily removed and replaced so as to adapt the length and diameter of the device for the needs and comfort of different users. In addition, the replaceable polymer sheath allows safe and sanitary use of one wireless device by more than one user. In addition, polymers are notorious for becoming oxidized and then hard and brittle, however the device of the invention need not be refurbished for this reason since the compliant polymer sheath may be easily removed and replaced whenever required. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to United States provisional patent application, Ser. No. 62/018,250, filed on Jun. 27, 2014. Priority to the provisional application is expressly claimed, and the disclosure of the application is hereby incorporated herein by reference in its entirety and for all purposes.
FIELD
[0002] The present disclosure relates generally to graph based relationships and more specifically, but not exclusively, to enhanced detection of fraudulent electronic transactions based on relationship graphs.
BACKGROUND
[0003] Both commercial and law-enforcement organizations have a vital interest in determining whether some attempted financial transactions are fraudulent. In this context, fraudulent means that a purchaser does not have legitimate authority to use funds involved in the transaction. As an example, the purchaser may be using a stolen identity and/or using funds (or privileges) that properly belong to the entity whose identity has been stolen. Such funds include a credit card account, a debit card account, an online banking account, and an e-commerce site-issued online account.
[0004] It is difficult to detect all fraudulent transactions using conventional systems and methods. There are not only several types of fraud, but also the nature of fraudulent activity is that it is disguised. For example, purchase fraud includes using stolen accounts, creation of new accounts, using a false identity, and demonstrating chargeback fraud (e.g., demanding a refund). In other cases, the merchant is the fraud perpetrator: billing excess charges, failing to deliver products, or not existing as a legitimate business. Accordingly, conventional systems for detecting fraudulent transactions typically use an assemblage of methods, each of which detects and assesses some attribute which distinguishes transactions that are likely valid from likely fraudulent.
[0005] Various schemes have been used to detect or block fraudulent transactions. These schemes include using a secret password, a biometric identifier, a monetary limit, and examining the pattern of transactions. The first three methods (i.e., using secret passwords, biometric identifiers, and monetary limits) provide simple pass-fail tests. However, passwords and biometrics often are not used for credit card transactions because legitimate customers and vendors find them to be too troublesome or unpleasant. Setting a maximum monetary limit is flawed because it can allow many small fraudulent transactions while also blocking large but legitimate transactions.
[0006] A particular problem for current fraud detection systems is adequately following and modeling the complex patterns of online commerce. As online shopping and other transactional activity becomes easier, more common, and more global, users are engaging in ever more complex transactional patterns with regard to which merchants receive their business. The transactional patterns amount to a social network, with some shoppers referring peer shoppers to particular merchants, and with some shoppers intentionally (or unintentionally) emulating the shopping characteristics of like-minded shoppers. Two merchants can be related, not necessarily because they sell similar products, but because they are both used by many shoppers.
[0007] Many common fraud detection schemes perform a time-consuming analysis of their full set of transactional data, to try to define global rules, so that the same rules would apply to all shoppers or financial accounts. This approach not only misses fast-moving changes in shopping behavior, but also fails to allow for the legitimate differences in shopper behavior. If the fraud detection rules are individualized, they typically only include parameterized versions of a single filtering or rule model.
[0008] In view of the foregoing, a need exists for an improved system that leverages the constantly changing social network and social role behavior of electronic transactions to better measure the likelihood that a legitimate user would submit a transaction to the specified merchant in an effort to overcome the aforementioned obstacles and deficiencies of conventional fraud detection systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is an exemplary top-level block diagram illustrating an embodiment of a fraud detection system.
[0010] FIG. 2 is an exemplary top-level block diagram illustrating one embodiment of the transaction validator of the fraud detection system of FIG. 1 .
[0011] FIG. 3 is an exemplary diagram illustrating an embodiment of an account-merchant relationship table that can be stored in the transaction validator of FIG. 2 .
[0012] FIG. 4A is an exemplary diagram illustrating another embodiment of the account-merchant relationship table that can be stored in the transaction validator of FIG. 2 .
[0013] FIG. 4B is an exemplary top-level block diagram illustrating another embodiment of the transaction validator of the fraud detection system of FIG. 1 .
[0014] FIG. 5 is an exemplary diagram illustrating an embodiment of a merchant relationship table that can be stored in the transaction validator of FIG. 2 .
[0015] FIG. 6 is an exemplary diagram illustrating another embodiment of the merchant relationship table that can be stored in the transaction validator of FIG. 2 .
[0016] FIG. 7A is an exemplary flowchart illustrating one embodiment of a method of validation using the fraud detection system of FIG. 1 .
[0017] FIG. 7B is an exemplary flowchart illustrating further details of the method of validation illustrated in FIG. 7A .
[0018] FIG. 7C is an exemplary flowchart illustrating one embodiment of the transaction validity evaluation of FIG. 7B .
[0019] FIG. 7D is an exemplary flowchart illustrating one embodiment of a method of computing a merchant relatedness score of FIG. 2 .
[0020] FIG. 8 is an exemplary flowchart illustrating one embodiment of a method of defining an eligible path that can be used with the validation method of FIG. 7 .
[0021] FIG. 9 is an exemplary diagram illustrating another embodiment of an account-merchant relationship table that can be stored in the transaction validator of FIG. 2
[0022] FIG. 10 is an exemplary top-level block diagram illustrating another embodiment of the transaction validator of FIG. 2 that operates with a transaction log.
[0023] It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Since currently-available fraud detection systems are deficient because they fail to capture the rapidly changing and complex social network-like nature of purchaser-merchant behavior, a fraud detection system that provides a dynamically evolving merchant relationship graph can prove desirable and provide a basis for a wide range of fraud detection applications, such as the ability to predict the likelihood that a given account would make a transaction with a given merchant. This result can be achieved, according to one embodiment disclosed herein, by a fraud detection system 1000 as illustrated in FIG. 1 .
[0025] Turning to FIG. 1 , the fraud detection system 1000 includes a client device 101 in communication with a transaction server 102 . A customer can submit a transaction request 100 from the client device 101 to the transaction server 102 . The client device 101 is any network-connected device through which the customer can submit a transaction to the transaction server 102 . For example, the client device 101 includes specialized devices, such as bank automated teller machines (ATMs) and point-of-sale (POS) devices, as well as personal computers and mobile phones. The transaction server 102 is any network-connected device equipped to accept the transaction request 100 from the client device 102 . For example, the transaction server 102 includes web application servers and database servers.
[0026] The fraud detection system 1000 further includes a transaction validator 103 in communication with the transaction server 102 . In some embodiments, the transaction server 102 and the transaction validator 103 are components within the same computer. In other embodiments, the transaction server 102 and the transaction validator 103 are disposed within separate computers and communicate with one another via a network connection (not shown).
[0027] In some embodiments, the transaction request 100 contains information equivalent to a Financial Account ID (FID), a Merchant ID (MID), and a monetary amount (AMT). In some embodiments, the transaction request 100 contains information, such as a timestamp (TIME) and a description of any goods to be exchanged (DESC).
[0028] The transaction server 102 receives the transaction request 100 and forwards the transaction request 100 to the transaction validator 103 . The transaction validator 103 performs a real-time analysis of the transaction request 100 to predict the likelihood that the transaction request 100 is fraudulent. The transaction validator 103 uses this predicted likelihood to generate a validity assessment 104 , which the transaction validator 103 sends back to the transaction server 102 . In some embodiments, the validity assessment 104 can have one of two values: “Valid” or “Invalid.” If the validity assessment 104 is “Valid,” then the transaction server 102 proceeds with executing the transaction request 100 . If the validity assessment 104 is “Invalid,” then the transaction server 102 will not execute the transaction request 100 . If the transaction of transaction request 100 already has been started, the transaction is rolled back. Here, rolling back refers to the reversal of any parts of the transaction operations requested in transaction request 100 that may have already taken place. In either case, the transaction server 102 replies to the client device 101 , indicating whether the transaction succeeded or failed.
[0029] Turning now to FIG. 2 , the transaction validator 103 can include any number of components as desired. For example, as shown in FIG. 2 , the transaction validator 103 includes a merchant relationship validator 202 , an account-merchant relationship table 204 and a merchant relationship table 205 . In an alternative embodiment, there are optional transaction validator modules 203 . The optional transaction validator modules 203 can perform a fraud risk assessment of the values of any, or all, of the following fields that can be included in the transaction request 100 : the Financial Account ID (FID), the Merchant ID (MID), the monetary amount (AMT), and a timestamp (TIME). If the transaction request 100 contains additional fields, such as an account holder name, email address, a web domain name of the transaction requester's organization or of the merchant business, or an IP address, these may also be used in a fraud risk assessment. In some embodiments, the optional transaction validator modules 203 compare the identifying information in the transaction request 100 , such as any or all of FID, MID, an account holder name, an email address of the account holder, the web domain, and an IP address, against lists of identities that historically have been known or suspected to be involved with fraud. In some embodiments, the optional transaction validator modules 203 check to see how much the field values in the transaction request 100 deviate from the historically typical values for the particular user or account. For example, if account A1 historically has only made purchases less than $200, but in a particular transaction request 100 , A1's amount is over $5000, the optional transaction validator modules 203 may determine that the particular transaction request 100 has a higher fraud risk and will therefore assign the validity score 213 a False value (if Boolean) or a low number (if numeric).
[0030] A validation supervisor 201 is responsible for coordinating the merchant relationship validator 202 with any other transaction validator modules 203 to generate a single response to the transaction server 102 . The validation supervisor 201 will forward a copy of the transaction request 100 to the merchant relationship validator 202 and to the other transaction validator modules 203 .
[0031] The merchant relationship validator 202 creates, maintains, and analyzes the account-merchant relationship table 204 and the merchant relationship table 205 in order to provide enhanced assessment of the fraud risk of transaction request 100 . The merchant relationship validator 202 reports its assessment in the form of a merchant relatedness score 200 .
[0032] The account-merchant relationship table 204 stores a summary of the transactions between financial accounts and merchants. For example, a sample data entry 300 that can be stored in the account-merchant relationship table 204 is shown in FIG. 3 . As illustrated, each sample data entry 300 (e.g., a row) in the account-merchant relationship table 204 contains fields for FID, MID, and a count of transactions between the financial accounts and merchants. In an alternative embodiment, the account-merchant relationship table 204 contains attribute fields, such as an average and maximum size of financial transactions. Each row in this table can be interpreted as an edge in an account-merchant bipartite graph 304 , such as shown in FIG. 4A .
[0033] Stated in another way, the collection of one or more sample data entries 300 that can be stored in the account-merchant relationship table 204 is analogous to the account-merchant bipartite graph 304 .
[0034] Turning to FIG. 4B , in some embodiments, the account-merchant relationship table 204 and the merchant relationship table 205 are data structures within a database (such as a merchant database 220 ). In one embodiment, the account-merchant relationship table 204 and the merchant relationship table 205 are tables in a relational database. In an alternative embodiment, the account-merchant relationship table 204 and the merchant relationship table 205 are graph structures within a graph database. In yet another embodiment, the merchant relationship validator 202 can be implemented as database programs within a database management system (such as a merchant database management system (DBMS) 230 ).
[0035] The merchant relationship table 205 can be a data table having entries that store one or more relationship attributes between two merchants. For example, a sample data entry 500 that can be stored in the merchant relationship table 205 is shown in FIG. 5 . As illustrated, each sample data entry 500 (e.g., a row) in the merchant relationship table 205 contains fields for the relationship attributes: a commonality score 501 and optional other relationship attributes 502 .
[0036] Each data entry 500 in merchant relationship table 205 can be interpreted as an edge in a merchant relationship graph 305 , as shown in FIG. 6 . The commonality score 501 between merchants mx and my in merchant relationship table 205 is equal to the edge weight for edge (mx, my) in merchant relationship graph 305 . Stated in another way, the merchant relationship table 205 is informationally analogous to the merchant relationship graph 305 .
[0037] When the transaction server 102 receives the transaction request 100 , the transaction server 102 can perform a full fraud-detecting and transaction-servicing method according to any method described herein, including a fraud detection method 7000 shown in FIG. 7A .
[0038] Turning to FIG. 7A , the fraud detection method 7000 begins with the client device 101 submitting the transaction request 100 (e.g., for an account fi to a merchant mx) to the transaction server 102 (step 701 ).
[0039] In step 702 , the transaction server 102 requests that the transaction validator 103 assess the validity of transaction request 100 .
[0040] When the transaction validator 103 receives the transaction request 100 from the transaction server 102 , the transaction validator 103 begins the validation test 710 (which will be described further below). The transaction validator 103 concludes the validation test 710 by sending its validity assessment 104 to the transaction server 102 .
[0041] After performing the validation test 710 , the transaction server 102 conditionally executes the transaction request (step 720 ).
[0042] Also after performing the validation test 710 , the merchant relationship validator 202 then uses the data from the transaction request 100 to update the statistics recorded in the account-merchant relationship table 204 and the merchant relationship table 205 (step 730 ).
[0043] With reference now to FIG. 7B , one embodiment of the validation test in step 710 , the conditional execution in step 720 , and the tables update in step 730 is shown in greater detail.
[0044] Turning to FIG. 7B , the validation test in step 710 (e.g., for the account fi to the merchant mx) begins when the merchant relationship validator 202 computes the cumulative relatedness between the merchant mx and the set of merchants previously used by customer account fi (step 703 ). In one embodiment, the merchant relationship validator 202 uses the merchant commonality 501 from the merchant relationship table 205 , and optionally the amount of the transaction, to generate the merchant relatedness score 200 and sends the generated merchant relatedness score 200 to the validation supervisor 201 . This step 703 is discussed in further detail below with reference to FIG. 8 .
[0045] If there are other transaction validator modules 203 , the validation supervisor 201 issues requests to some or all of the other optional transaction validator modules 203 (step 704 ). Each of the other transaction validator modules 203 reports its result as a validity score 213 . The data type of the validity score 213 may be a Boolean (True or False value), or the data type may be numerical. In some embodiments, each of the validity scores 213 and the merchant relatedness score 200 has two possible values. In some embodiments, the validation supervisor 201 prioritizes the other transaction validator modules 203 such that the merchant relationship validator 202 and some transaction validator modules 203 are always used, and some other transaction validator modules 203 are used subsequently, if and only if the higher priority validation tests do not produce conclusive results. For example, if the validator prioritization aspect of the validation supervisor 201 is implemented in an imperative programming language such as C or Java, then the prioritization can be implemented by using conditional IF statements in sequence. An inconclusive validation test result could be, for example, noticing that the transaction request 100 is with a merchant in a foreign country. The cardholder may be traveling, or the card number may have been stolen.
[0046] As discussed above, the optional transaction validator modules 203 verify any aspects of the transaction request 100 other than the account-merchant relationship. Accordingly, the validation test in step 710 continues when the other optional transaction validator modules 203 perform their other validation tests and send validity scores 213 to the validation supervisor 201 (step 714 ). Other validation tests may include, for example, checking credit card numbers and purchaser identities against lists of known stolen cards and stolen identities.
[0047] Subsequently, in step 705 , the validation supervisor 201 evaluates the received validity scores 200 and 213 and tries to reach a decision on the validity of the transaction request 100 . One embodiment of the decision on the validity of the transaction request 100 in step 705 is shown in FIG. 7C .
[0048] With reference now to FIG. 7C , the validity scores 200 and 213 are classified by a degree of risk, for example as a high risk, a low risk, or an uncertain risk. For example, each validity score might be on a 0 to 5 point scale, where 0 or 1 is low risk, 4 or 5 is high risk, and 2 or 3 is uncertain risk. If any of the validity scores 200 and 213 is rated high risk (decision block 750 ), then the validation supervisor 201 determines that the transaction request 100 is “Invalid” and sends a negative validity assessment 104 (step 760 ). Otherwise, if none of the scores are given an uncertain risk (decision block 752 ), then all the validity scores 200 and 213 are determined to represent a low risk. The validation supervisor 201 determines that the transaction request 100 is “Valid” and sends a positive validity assessment 104 (step 762 ).
[0049] If neither of the two previous cases (from decision block 750 or decision block 752 ) is true, then it is the case that some of the validity scores 200 and 213 is given an uncertain risk. Then, if there are still other transaction validators 203 that have not yet returned a validity score 213 (decision block 754 ), then the validation supervisor 201 authorizes some or all of the remaining transaction validators 203 (step 766 ). However, if there are no more remaining transaction validators 203 (and there are some uncertain risk scores), then the validation supervisor 201 must use the available validity scores 200 and 213 to determine whether the transaction request 100 is “Valid” or “Invalid” (step 764 ). The validation supervisor 201 may use any viable decision method. Methods include having step 764 sending a positive validity assessment 104 (optimistic), having step 764 sending a negative validity assessment 104 (pessimistic), and/or having step 764 generating a random validity assessment 104 (probabilistic).
[0050] Returning to FIG. 7B , the validation test in step 710 continues by determining whether the validation supervisor 201 reached a judgment (decision block 706 ). If so, then the fraud detection method 7000 continues to steps 720 and 730 discussed above. However, if the validation supervisor 201 did not reach a judgment, then the validation supervisor 201 selects additional transaction validators 203 to use, looping back to step 704 .
[0051] If the validity assessment 104 is positive (decision block 707 ), the transaction request 100 is executed (step 708 ). If the validity assessment 104 is negative (decision block 707 ), the transaction request 100 is aborted and rolled back if necessary (step 709 ). As stated earlier, rolling back refers to the reversal of any parts of the transaction operations requested in transaction request 100 that may have already taken place.
[0052] In step 730 , the merchant relationship validator 202 uses data from the transaction request 100 to update statistics in the account-merchant relationship table 204 and merchant relationship table 205 . In some embodiments, the step 730 may occur in parallel with step 720 .
[0053] As discussed above, the merchant relationship validator 202 can use the edge-weighted merchant relationship graph 305 to compute the cumulative relatedness between the merchant mx and the set of merchants previously used by customer account fi in step 703 . In some embodiments, the merchant relationship table 205 stores the commonality 501 between merchants for the cases of one degree of separation. The commonality score 501 takes into account only first-degree connections between merchants. That is, a first-degree connection between merchants mx and my occurs when an account has transacted with both mx and my. However, more distant relationships between merchants are possible. For example, while no single account may have transacted with both merchants m1 and m4, there may be some accounts that have transacted with both m1 and m2, and a disjoint set of accounts which have transacted with both m2 and m4. Therefore, there exists some transitive relatedness between m1 and m4. With reference to FIG. 6 , three indirect connections between m1 and m4 are shown:
[0054] m1→m2→m4 (path 1)
[0055] m1→m3→m4 (path 2)
[0056] m1→m2→m3→m4 (path 3)
[0057] The merchant relationship validator 202 extracts all eligible paths from the customer Account fi's past merchants to the current merchant mx in the merchant relationship graph 305 and applies a path aggregation method, which combines all the eligible paths to produce a merchant relatedness score 200 . Any path aggregation method can be used. For example, in one embodiment, the path aggregation method is as follows:
[0058] The path aggregation method comprises mathematical rules which specify, for each individual path or set of paths P between merchants mx and my, a function value f(mx, my, P). The merchant relationship score 200 for (mx, my) is equal to the function value for the collection of all eligible paths from mx to my.
[0059] To compute the merchant relationship score 200 between merchants mx and my, merchant relationship validator 202 starts by computing the function values for the individual edges which comprise the full set of eligible paths from mx to my. The merchant relationship valuator 202 continues by computing the function values for longer paths and for paths in parallel with one another, until the merchant relationship validator 202 has computed the function value for the set of all eligible paths between mx and my. To compute the function values for individual edges and for larger groupings of edges, the merchant relationship validator 202 applies the following four rules:
[0060] 1. Single edge: The function value of a single edge is the edge's merchant commonality score 501 . A single edge is a path collection containing one path of length 1.
[0061] 2. Series aggregation: If a path collection P1(mx,my) is appended to a path collection P2(my,mz) to make a longer path collection Q(mx,mz), the function value of Q(mx,mz) is less than or equal to either the function value P2(mx,my) or the function value P2(my,mz). For example, one particular rule is Q(mx,mz) =min(P1(mx,my),P2(my,mz))−1.
[0062] 3. Parallel aggregation: If a path collection P1 (mx,my) is merged with another path collection P2(mx, my) to make a larger collection P3(mx, my), then the function value P3(mx, my) is greater than or equal to either the function value P1 (mx, my) or the function value P2(mx, my). For example, one particular rule is P3(mx, my) =max(Pl(mx, my), P2(mx, my))+1.
[0063] 4. Maximum value for path of length 0: If a starting vertex (e.g., a past merchant of fi) is the same as the destination vertex (e.g., the current merchant mx), then this is a path with length 0. This path's function value is greater than that of any path with nonzero length. In one embodiment, the merchant relationship validator 202 first computes the function value for the aggregation of all the nonzero length paths. Then, if there is a zero length path, the merchant relatedness score 200 is set to be even higher than the function value of the set of non-zero length paths. Alternately, in another embodiment, if an account fi has previously transacted with the merchant mx, the merchant relationship validator 202 can automatically assign the transaction request 100 a very high relatedness score 200 . The merchant relationship validator 202 would not need to consider any non-zero paths to compute the relatedness score 200 .
[0064] As previously discussed, the merchant relationship validator 202 determines whether a path between two vertex points is an eligible path. In the preferred embodiment, all paths that are shorter than a predefined limit are eligible. Using a predetermined limit advantageously avoids an excessive number of paths. In another embodiment, only shortest paths from the start vertex to the end vertex are eligible. Longer paths are not eligible. To better understand these two embodiments for limiting the eligible paths, consider a 5 -vertex graph in which every vertex has a direct connection to every other edge. The vertices in this example are A, B, C, D, and E. Because the graph is fully connected, any sequence of these five letters which begins with A and ends with B corresponds to a path between A and B. In an embodiment in which only shortest paths are eligible, then AB would be the only eligible path. In an embodiment in which all paths with up to 2 edges are eligible, than AB, ACB, ADB, and AEB are the eligible paths.
[0065] An example of the path aggregation method is illustrated in FIG. 7D . Here, the merchant relationship validator 202 computes the merchant relatedness score 200 between m1 and m4, using the merchant relationship graph 305 . In step 770 , the merchant relationship validator 202 computes the function values for paths of length 1 . The function values are equal to the merchant commonality scores 501 . In the next step 772 , the merchant relationship validator 202 applies the series aggregation rule to compute the net function values for single paths of length 2. In the third step 703 , the validator 202 applies the parallel aggregation rule to merge all the paths of either length 1 or length 2 between the same two vertices. For example, there are two paths of length 2 between ml and m4, one path via m2, and another path via m3. There is no direct path. The aggregate function value f(m1, m4, all)=1. There is also a path of length 3 between m1 and m4, with relatively high commonality scores 501 on two of those three edges, but length 3 paths have not been considered yet. If the fraud detection system 1000 or the transaction request 100 has set the eligible path length limit to be 2, then the merchant relatedness score 200 computation is done. The merchant relatedness score is 1, the same as the function value for all paths between m1 and m4.
[0066] The overall path aggregation computation is analogous to determining the conductance in an electrical network. Electrical resistance—the inverse of electrical conductance—is easy to calculate and handles the special case of a zero-length path (e.g., when the account fi has transacted with the merchant mx before) by simply assigning a resistance of 0. In particular, electrical resistance follows these rules:
[0067] 1. The resistance of a merchant-merchant edge is the inverse of the edge's weight.
[0068] 2. When there are two parallel paths, the net resistance is the inverse of the sum of the inverses of the individual path resistances.
[0069] 3. When a path consists of two subpaths in series, the net resistance is the product of the resistances of the subpaths.
[0070] 4. The resistance from a point to itself is 0.
[0071] FIG. 8 shows a recursive function 8000 to compute electrical resistance in a merchant-merchant network (e.g., the merchant relationship graph 305 ) for paths whose length is no longer than a maximum length.
[0072] In step 703 shown in FIG. 7B , the merchant relationship validator 202 uses inverse resistance as the merchant relatedness score 200 . Turning to FIG. 8 , the merchant relationship validator 202 initiates a resistance function 8000 with three input parameters: a startVertex, an endVertex, and a depth of 0 (step 801 ). If the function 8000 is initialized such that the startVertex is the same as the endVertex (decision block 802 ), then the merchant relationship validator 202 returns a Resistance=0 (step 803 ). Otherwise, if the function 8000 later reaches the endVertex (decision block 804 ), then the merchant relationship validator 202 returns Resistance=1 (step 805 ). This return value 812 will be used as a multiplication factor. Otherwise, if the startVertex is different than the endVertex, then each neighbor of the startVertex potentially forms a path to the endVertex. For each neighbor Y of the startVertex (decision block 807 ), the merchant relationship validator 202 calculates a path resistance as the resistance from the startVertex to Y (steps 809 and 810 ), multiplied by the resistance from Y to the endVertex (step 811 ). The total resistance is the inverse of the sum of the inverse resistance of each neighbor branch (steps 808 and 811 ).
[0073] In some embodiments, the merchant relationship score 200 can have a fixed range of values (e.g., from 1 to 10) or be open-ended (i.e., with either no upper limit, no lower limit, or both). One possible interpretation of the value of the merchant relationship score 200 is that higher scores indicate stronger relationship and weaker risk. Any scoring system is acceptable, as long as the merchant relationship validator 202 and the validation supervisor 201 are based on the same interpretation.
[0074] In an alternative embodiment (e.g., employing the electrical resistance analogy discussed above), a score of 0 can be interpreted as maximum relatedness while increasing values can be interpreted as weaker relatedness.
[0075] The strongest possible relationship is when the account fi in question has transacted with the merchant mx in question several times before. In the resistance network embodiment, this strong direct relationship corresponds to a resistance of 0, which can be directly assigned a merchant relationship score of 0.
[0076] The aforesaid method for computing a path aggregation value provides a method for computing the merchant relativeness score 200 between any two merchants in the merchant relationship graph 305 . When the client device 101 submits a transaction request 100 , what the client needs to know, however, is not a relatedness between two merchants but a fraud risk between an account and a merchant. To complete the validation test 703 , the validation supervisor 202 computes not just one merchant relatedness score 200 . Instead, the merchant relationship validator 202 computes a merchant relatedness score 200 between the merchant mx of the transaction request 100 and each of the merchants previously used by the account fi of the transaction request. If fi has previously transacted with fifteen merchants, then the merchant relationship validator 202 computes up to fifteen merchant relatedness scores 200 .
[0077] The merchant relationship validator 202 may not need to compute fifteen scores. If one merchant's validation assessment 104 is positive, then the validation supervisor 201 can terminate the validation test 710 .
[0078] Returning to FIG. 7B , in step 720 the merchant relationship validator 202 updates both the account-merchant relationship table 204 and the merchant relationship table 205 . In some embodiments, the merchant relationship validator 202 first updates the account-merchant relationship table 204 . The merchant relationship validator 202 queries the account-merchant relationship table 204 to see if the account-merchant relationship table 204 already contains a row for the current (fi, mx) pair. If it does, the merchant relationship validator 202 increments the transaction count attribute in that row. The merchant relationship validator 202 also updates any other data fields in that row that are affected by the new transaction. If there is no such row, then the merchant relationship validator 202 adds a row to the account-merchant relationship table 204 , with an initial count of 1.
[0079] The merchant relationship validator 202 next updates the merchant relationship table 205 . A transaction with mx potentially affects the commonality score 501 between mx and each other past merchant of fi.
[0080] The following section describes several embodiments for the commonality score 501 (e.g., the edge weight) between two merchants. The commonality between two merchants mx and my (as distinguished from the cumulative, transitive relatedness) can be the sum of the commonalities contributed by each financial account:
[0000] sim ( mx, my )=Σ{all accounts fi} C _fi ( mx, my )
[0000] where C_fi (mx, my) is the commonality score 501 contributed by the account fi.
[0081] The number of transactions between fi and mx is notated as n(fi, mx). This number can be read directly from the account-merchant relationship table 204 .
[0082] A simple commonality score 501 for one account fi is the lesser of n(fi, mx) and n(fi, my). That is, the relationship score is the lesser of the number of fi's transactions with mx and the number of fi's transactions with my. The net commonality score 501 sim(mx, my) is the sum of the account-specific relationship scores, taken over all accounts. This scoring scheme has the advantage of being simple.
[0083] The contribution from account fi is C1_fi (mx, my)=min(n(fi, mx), n(fi, my))
[0084] In an alternative embodiment, the relationship can represent an average. Specifically, whether the value n(fi, mx) is large or not is relative. One way to account for this relativity is to compare n(fi, mx) to the total number of transactions by user fi. Accordingly, the relatedness is the commonality score 501 determined above divided by the total number of transactions enacted by fi:
[0085] C2_fi (mx, my)=C1_fi (mx, my)/n(fi) where n(fi)=total number of transactions enacted by fi.
[0086] In yet another alternative, the relative importance of the number of transactions considers the total number of transactions with a given merchant. If one merchant is extremely popular, then the fact that an account has transacted with that merchant several times should not carry much significance. In this embodiment, the number of transactions with each merchant is divided by the logarithm of the total number of transactions with that merchant by any account, n(m). The logarithm is used because the range of values for n(m) can span many orders of magnitude, and the logarithm will compress the range. However, another compression function or no compression function at all can be used.
[0000] C 3 — fi ( mx, my )=min( r ( fi, mx ), r ( fi, my ))
[0087] where r(f, m)=n(f, m)/log n(m)
[0088] and n(m)=total number of transactions with merchant m.
[0089] Each of the commonality score 501 s above, C1_fi; C2_fi; and C3_fi, is for the contribution of a single financial account. The total direct relatedness between two merchants is computed by add the scores from each individual financial account.
[0090] In yet another alternative embodiment, the commonality score 501 between two merchants can consider each merchant as possessing a set of accounts. Accordingly, the commonality score 501 is determined by measuring the degree that these two sets overlap. For example, if F(mx) is the set of accounts which have transacted with a merchant mx, the relationship score is the number of accounts which mx and my have in common, divided by the number of accounts that mx and my each have when considered separately:
[0000] sim ( mx, my )=| F ( mx )∪ F ( my )|/[| F ( mx )|+| F ( my )|]
[0091] In this embodiment, sim(mx, my) is not simply the sum of contributions from each account. On the other hand, it is necessary to compute the F(m) sets, to count their members, and to perform a set union operation. F(m) can be computed by selecting and combining the records in the account-merchant relationship table 204 , which reference a particular merchant m. When the number of merchants and accounts is large, a preferred embodiment performs the computation efficiently through distributed computation. Stated in another way, the Merchant Relationship Validator 202 may contain multiple processing units, each responsible for a subset of the merchants or accounts.
[0092] Relationship Scores Using Merchant and Transaction Attributes
[0093] In addition to the number of transactions which share the same FID, the monetary size and the recency of shared transactions can also be useful contributors to risk assessment. In some embodiments, as show in FIG. 9 , the account-merchant relationship table 204 can include columns such as illustrated in an account-merchant relationship entry 900 to record information about the size of transactions and the recency of transactions.
[0094] As an example, in one embodiment, the commonality score 501 between merchants mx and my is the total dollar amount transacted by the common accounts with those two merchants, divided by the total amount transacted by any accounts with these merchants. If amt(fi, mx) is the total amount transacted by account fi with merchant mx, and amt(mx) is the total amount transacted with merchant mx (by any account), then
[0000] sim ( mx, my )=Σ{each account fi in ( F ( mx )∪ F ( my ))} [amt( fi, mx )+amt( fi, my )]/[amt( mx )+amt( my )]
[0095] Any suitable method to record and measure transaction age or recency can be used as desired. In one embodiment, transactions are assigned a weight that decreases with age. In other embodiments, a strict time limit is specified: transactions older than a set duration are not considered at all in computing the statistics in the account-merchant relationship table 204 and in the merchant relatedness score 200 . The gradual aging and the strict time limit can be applied together or independently.
[0096] In some embodiments, the relative location of merchants may be included as a risk assessment. Being close increases the strength of relationship between two merchants. If an account has previously transacted with many merchants that are physically close to the proposed merchant, then the risk may be deemed lower.
[0097] Lower and Upper Score Thresholds
[0098] If an account fi has previously transacted with N merchants and then transacts with one additional merchant, this potentially added N new entries to the merchant relationship table 205 and to its analogous merchant relationship graph 305 . If N is a large number, then this is a large increase in table entries in response to one new transaction. To limit this increase, in some embodiments, a minimum threshold is set for the value of the commonality score 501 . The value is only recorded in the merchant relationship table 205 if the value is at least as large as the threshold.
[0099] In some embodiments, the fraud detection system 1000 may define an upper threshold for commonality score 501 , meaning that if the score is higher than this level, then the risk is considered negligible and no further computation is needed. The merchant relationship validator 202 may define a special value to represent the upper threshold. Once a merchant-merchant pair (mx, my) achieves this score, additional nonfraudulent transactions with either mx or my will not affect this score.
[0100] Alternative Method for Updating Statistics in Relationship Tables
[0101] In the embodiment disclosed with reference to FIG. 7 , the account-merchant relationship table 204 and the merchant relationship table 205 are updated each time that a transaction request 100 undergoes the fraud detection method 7000 .
[0102] Turning to FIG. 10 , an alternative embodiment of the system 1000 is shown wherein the tables of the transaction validator 103 are not updated at the end of each iteration of the fraud detection method 7000 . Instead, each transaction request 100 that is assessed to be valid in step 707 is added to an executed transaction queue 250 immediately after being assessed. Periodically, the merchant relationship validator 202 reads the executed transaction queue 210 in order to update the relationship tables (tables 204 and 205 ). The update operation is like that of the tables update in step 730 , except the transaction request comes from the executed transaction queue 210 instead of being the newly received transaction request 100 . After the relationship tables 204 and 205 are updated, the executed transaction queue 250 is flushed. This method, which updates tables 204 and 205 in batches of transaction queue 250 entries rather than when each transaction request 100 is received, may be more time efficient.
[0103] In an alternative embodiment, there is not a separate executed transaction queue 210 . Instead, the transaction server 102 is coupled to or contains a transaction log 150 , as shown in FIG. 10 . As the transaction server 102 conditionally executes the transaction request, such as described in step 720 shown in FIG. 7A , the transaction request 100 is stored sequentially in the transaction log 150 ; each new transaction is appended to the end of the transaction log 150 .
[0104] Rather than having and maintaining a separate queue, this embodiment requires a single memory value, for example, an update pointer 152 . The update pointer 152 records the location within the transaction log 150 of the last transaction that was used to update the account-merchant relationship table 204 and the merchant relationship table 205 . Periodically, the update pointer 152 is accessed and the sequence of transactions from the location of the update pointer 152 to the most current are read and used to perform several updates to the relationship tables (tables 204 to 205 ). The update pointer 152 is then relocated to the end of the transaction log 104 .
[0105] For example, when the fraud detection system 1000 is used for the first time, the update pointer 152 points to item 0 in the transaction log 150 , because no transactions have been recorded in the relationship tables (tables 204 and 205 ). Suppose that after fifty transactions transpire, the validation supervisor 201 and the transaction server 102 agree to update the account-merchant relationship table 204 and the merchant relationship table 205 . The fifty transaction requests are sent from the transaction log 150 to the merchant relationship validator 202 . The merchant relationship validator 202 uses these transaction requests from the transaction log 150 in order to update the tables 204 and 205 . The update pointer 152 is repositioned to point at item fifty in the transaction log, that is, at the point in the sequential log between those transactions that have gone through tables update in step 730 and those that have not yet.
[0106] The described embodiments are susceptible to various modifications and alternative forms, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the described embodiments are not to be limited to the particular forms or methods disclosed, but to the contrary, the present disclosure is to cover all modifications, equivalents, and alternatives. | Systems and methods for enhanced detection of fraudulent electronic transactions are disclosed. In one embodiment, a system uses the ongoing stream of transactions to construct and maintain a dynamically evolving merchant relationship graph. When a proposed transaction is submitted to the system, the system computes a predicted likelihood that the given account would make a transaction with these characteristics with the given merchant. The graph is used to compute transitive relatedness between merchants which may be indirectly associated with one another, as well as to compute aggregate relatedness, when there are multiple avenues of relationship between two merchants. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to footwear. More particularly, the invention relates to a method and articles for selective adornment of a shoe whereby a single shoe may take on virtually unlimited outward appearances.
BACKGROUND OF THE INVENTION
[0002] As particularly shown in FIG. 1 , a typical shoe 20 as well known in the art generally comprises an upper 21 attached through a welt 27 to the outsole of the shoe 20 , which may have affixed thereto any manner of heel arrangements. The upper 21 , which may be constructed of any of a variety of materials such as, for example, leather, satin, suede or canvas, generally includes the vamp 24 for covering the top part of the wearer's toes between the toe box 30 and the forward portion of the throat 28 of the shoe 20 , the quarter 22 for covering the sides and back 31 of the wearer's foot and the lining 25 interior to the shoe 20 extending generally about the area defined by the quarter 22 and running from the footbed 29 to the cuff 26 about the throat 28 of the shoe 20 . While any number of decorative elements may be incorporated into any particular design for a shoe 20 , including variations in material, color, decorative pattern or appliqué, ornamental stitching and the like, it is noted that in generally any selected design element is permanent and not subject to change.
[0003] Because a shoe of any reasonable quality represents a substantial financial investment, the selection of any one shoe appropriate for multiple uses or occasions is often a frustrating task that more often than not ends in the purchase of multiple styles. In addition to being costly, however, this course of action also presents a storage problem, shoes being generally bulky and cumbersome to organize. As a result of these shortcomings, the use of spats has gained some popularity with those looking to add some variety to their wardrobe or attempting to economically follow a trend. Unfortunately, the manner of application of spats—in particular the use of ankle straps and/or straps extending under the outsole—generally presents an undesirable appearance counteracting any styling added by the spats.
[0004] It is therefore an overriding object of the present invention to improve over the prior art by the presentation of a method and articles for selective adornment of a shoe whereby a single shoe may take on virtually unlimited outward appearances, the method and articles being usable without indication that the shoe is not of unitary construction. Additionally, it is an object of the present invention to present such a method and articles that are comfortable to the wearer, simple to use and inexpensive to employ.
SUMMARY OF THE INVENTION
[0005] In accordance with the foregoing objects, the present invention—an adornment for application to an article of footwear—generally comprises a decorative element sized and shaped for conforming application about the quarter of a shoe and a plurality of fasteners operably affixed to the decorative element and adapted to removably affix the decorative element directly to the quarter of the shoe. The decorative element may comprise a decorative panel, a decorative construct, a decorative strip or the like. In the case of a panel or construct, the present invention generally contemplates the use of clips or clasps for engaging the cuff about the throat of the shoe. In the case of a decorative strip, however, it is found that a novel use of magnetic fasteners is simple, efficient and effective.
[0006] Finally, many other features, objects and advantages of the present invention will be apparent to those of ordinary skill in the relevant arts, especially in light of the foregoing discussions and the following drawings, exemplary detailed description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Although the scope of the present invention is much broader than any particular embodiment, a detailed description of the preferred embodiment follows together with illustrative figures, wherein like reference numerals refer to like components, and wherein:
[0008] FIG. 1 shows, in a left side elevational view, a typical shoe as known in the prior art and generally suitable for application thereto of the teachings of the present invention;
[0009] FIG. 2 shows, in a front side elevational view, a first preferred embodiment of an adornment constructed according to various teachings of the present invention showing, in particular, the outward decorative appearance presented thereby;
[0010] FIG. 3 shows, in a rear side elevational view, the adornment of FIG. 2 showing, in particular, a first fastener arrangement suitable for use in the depicted and other embodiments of the present invention;
[0011] FIG. 4 shows, in a left side elevational view, a shoe generally of the character of that of FIG. 1 having applied thereto the adornment of FIG. 2 ;
[0012] FIG. 5 shows, in a top plan view, a second preferred embodiment of an adornment constructed according to various teachings of the present invention showing, in particular, outward decorative appearance presented thereby;
[0013] FIG. 6 shows, in a bottom plan view, the adornment of FIG. 5 showing, in particular, a second fastener arrangement suitable for use in the depicted and other embodiments of the present invention;
[0014] FIG. 7 shows, in a left side elevational view, a shoe generally of the character of that of FIG. 1 having applied thereto the adornment of FIG. 5 ;
[0015] FIG. 8 shows, in a left side elevational view, a shoe generally of the character of that of FIG. 1 having applied thereto a third preferred embodiment of an adornment constructed according to various teachings of the present invention;
[0016] FIG. 9 shows, in a front side elevational view, a fourth preferred embodiment of an adornment constructed according to various teachings of the present invention showing, in particular, outward decorative appearance presented thereby;
[0017] FIG. 10 shows, in a rear side elevational view, the adornment of FIG. 9 showing, in particular, a portions of a third fastener arrangement suitable for use in the depicted embodiment of the present invention;
[0018] FIG. 11 shows, in a front side elevational view, an alternatively preferred embodiment of the adornment of FIG. 9 showing, in particular, a variation of the third disclosed fastener arrangement;
[0019] FIG. 12 shows, in a rear side elevational view, the adornment of FIG. 11 showing, in particular, the reversible nature of the depicted embodiment;
[0020] FIG. 13 shows, in a top plan view, a shoe having incorporated therein portions of the fastener arrangement of the adornments of FIGS. 9 and 11 ;
[0021] FIG. 14 shows, in a left side elevational view, additional details of the portions of the fastener arrangement shown in FIG. 13 ; and
[0022] FIG. 15 shows, in a left side elevational view, a shoe as generally shown in FIGS. 13 and 14 and having applied thereto an adornment as generally shown in either FIG. 9 or 11 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Although those of ordinary skill in the art will readily recognize many alternative embodiments, especially in light of the illustrations provided herein, this detailed description is exemplary of the preferred embodiment of the present invention, the scope of which is limited only by the claims appended hereto.
[0024] Referring now to FIGS. 2 through 15 , each preferred embodiment of the adornment 32 of the present invention is shown to generally comprises a decorative element 33 sized and shaped for conforming application on or about at least a portion of the nose 23 of the quarter 22 of a shoe and having associated therewith a plurality of fasteners 59 . In each embodiment, the fasteners 59 are adapted affix the implemented decorative element 33 directly to the quarter 22 of the shoe 20 without use of straps or the like such as generally present an undesirable outward appearance.
[0025] In a first preferred embodiment of the present invention, as particular shown in FIGS. 2 and 3 , the decorative element 33 generally comprises a panel 34 , which may be of unitary construction or may be formed as a laminate comprising, for example, a rigid core covered on at least the front face 35 thereof with fabric 36 or the like, which may be of a solid color or any desired decorative design or pattern, and which may be affixed with stitching 37 , glue and any substantially equivalent means. The rear face 78 of the panel 34 has affixed thereto a plurality of fasteners 59 . As particularly shown in FIG. 3 , a suitable fastener 59 may comprise a clasp 65 . As is generally conventional, such a clasp 65 preferably comprises a base 66 having mounting means such as, for example, mounting holes 67 that may be accept stitching 68 , rivets, glue or the like for affixing the clasp 65 to the rear face 78 of the panel 34 . Additionally, such a clasp 65 also preferably comprises a keeper 71 affixed thereto with a pivot 69 and spring arrangement 70 such that the keeper 71 is adapted to securely engage the cuff 26 of the shoe 20 to which the panel is to be attached. To this end, the keeper 71 may include one or more spurs 72 or prongs. In any case, as shown in FIG. 4 , the panel 34 is readily attached to the nose 23 of the quarter 22 of the shoe 20 giving great variety to the appearance otherwise presented in FIG. 1 .
[0026] In other preferred embodiments of the present invention, as particularly shown in FIGS. 5 , 6 and 8 , the decorative element 33 generally comprises a decorative construct 38 . In one such embodiment, as shown in FIGS. 5 and 6 , such a decorative construct 38 may comprise a first panel 39 , which may be of unitary construction or may be formed as a laminate comprising, for example, a rigid core covered on at least the top side 46 thereof with fabric 40 or the like, which may be of a solid color or any desired decorative design or pattern, and which may be affixed with stitching 42 , glue and any substantially equivalent means; a second panel 42 adjoined at an intersection 45 with the first panel 39 and which like the first panel 39 may be of unitary construction or may be formed as a laminate comprising, for example, a rigid core covered on at least the top side 46 thereof with fabric 43 or the like, which may be of a solid color or any desired decorative design or pattern, and which may be affixed with stitching 44 , glue and any substantially equivalent means; and, if desired one or more ornaments 47 such as, for example, the depicted bow 48 . In any case, the bottom side 49 of this construct has affixed thereto a plurality of fasteners 59 . Although the fasteners 59 may comprise clasps 65 as previously described, Applicant has found that for such a construct as described simple flat clips 60 are simple and sufficient in use. As particular shown in FIG. 6 , such clips 65 (which may also be used in connection with the embodiment of FIGS. 2 through 4 ) may simply comprise a metal element having a base 61 bent back over a fold 62 to form a keeper 63 . In any case, as shown in FIG. 7 , the described construct 38 is readily attached to the nose 23 of the quarter 22 of the shoe 20 , as well as to the vamp 24 of the shoe 20 , giving great variety to the appearance otherwise presented in FIG. 1 .
[0027] In a variation of the previously described decorative construct 38 , a decorative construct 38 may be formed as shown in FIG. 8 by the provision of a plurality of ornaments 50 or the like, each having affixed to the underside thereof a suitable fastener 59 and being interconnected one to another with one or more flexible elements 51 such as, for example, the depicted chains 52 . As clearly shown in FIG. 8 , this adornment 32 , like those previously discussed, also gives great variety to the appearance of the shoe 20 as otherwise presented in FIG. 1 .
[0028] Turning now then to FIGS. 9 through 15 , there is shown further preferred embodiments of the decorative element 33 of an adornment 32 implemented in accordance with the teachings of the present invention, which embodiments also make use of a novel fastener 59 . In these embodiments, as particularly shown in FIGS. 9 through 12 , the decorative element 33 comprises a flexible strip 53 , which is sized and shaped to substantially overlay the full quarter 22 of a shoe 20 . In a first specific embodiment, as particularly shown in FIGS. 9 and 10 , the flexible strip 53 is formed as a unitary element having a front face 54 , which is made to be decorative, and a rear face 55 . In a second specific embodiment, however, particularly shown in FIGS. 11 and 12 , the flexible strip 53 is formed as a laminate 56 having a first layer 57 and a second layer 58 , whereby the first layer 57 presents a decorative front face 54 and the second layer 58 presents an also decorative rear face 55 .
[0029] In a departure from the previously described embodiments, the fasteners 59 for the now described embodiments each comprise a magnetic fastener 73 . To this end, each embodiment of the flexible strip 53 is provided with a plurality of ferromagnetic elements 76 such as, for example, plates 77 or like structures comprising ferromagnetic material such as iron, nickel, cobalt, an alloy of neodymium or other rare earth (lanthanide) metal or the like. In the first described specific embodiment, as particularly shown in FIG. 10 , the ferromagnetic elements 76 are affixed (with glue or other suitable means) to the rear face 55 of the flexible strip 53 at generally regular intervals. In the second described specific embodiment, as particularly shown in FIGS. 11 and 12 , however, the ferromagnetic elements 76 are affixed to the flexible strip 53 (again at generally regular intervals) by interposing the ferromagnetic elements 76 between the first layer 57 and the second layer 58 of the laminate 56 . Forming the remainder of the magnetic fasteners 73 , a second set of ferromagnetic elements 74 , which may also comprise plates 75 or the like as previously described, are provided in connection with the shoe 20 on which the flexible strips 53 are to be employed. In particular, as shown in FIGS. 13 and 14 , the additional ferromagnetic elements 74 are disposed between the quarter 22 and the lining 25 of the upper 21 of the shoe 20 and spaced and otherwise arranged for pairwise mating alignment with the ferromagnetic elements 76 provided in connection with the flexible strips 53 .
[0030] Finally, in implementing the first specific embodiment of the flexible strips 53 ( FIGS. 9 and 10 ), at for each pair of aligned ferromagnetic elements forming one magnetic fastener 73 , one or both of the ferromagnetic elements 74 , 76 must be magnetized. Additionally, if both are magnetized, care must be taken to ensure that the dipoles of the resultant magnets are oriented such that the pairs of ferromagnetic elements 74 , 76 will attract one another with the front face 54 of the flexible strip facing outwardly away from the quarter 22 of the shoe 20 . In implementing the second specific embodiment of the flexible strips 53 ( FIGS. 11 and 12 ), however, only one of each pair of aligned ferromagnetic elements forming one magnetic fastener 73 should be magnetized, thereby enabling the flexible strip 53 to be reversed such that either front face 54 or the rear face 55 may be outwardly displayed with the flexible strip 53 in position for use as shown in FIG. 15 . In either case, as is clearly shown in FIG. 15 , this implementation like those previously described also gives great variety to the appearance of the shoe 20 as otherwise presented in FIG. 1 .
[0031] While the foregoing description is exemplary of the preferred embodiment of the present invention, those of ordinary skill in the relevant arts will recognize the many variations, alterations, modifications, substitutions and the like as are readily possible, especially in light of this description, the accompanying drawings and claims drawn thereto. For example, those of ordinary skill in the art will recognize that in implementing the second specific embodiment of the flexible strips 53 ( FIGS. 11 and 12 ) it is desirable that the ferromagnetic elements 74 associated affixed to the shoe 20 be chosen for magnetization, thereby requiring only one set of magnets as opposed to a set of magnets for every flexible strip 53 . In any case, because the scope of the present invention is much broader than any particular embodiment, the foregoing detailed description should not be construed as a limitation of the scope of the present invention, which is limited only by the claims appended hereto. | An adornment for application to an article of footwear includes a decorative element sized and shaped for conforming application about the quarter of a shoe and two or more fasteners operably affixed to the decorative element and adapted to removably affix the decorative element directly to the quarter of the shoe. The decorative element may be formed as a decorative panel, a decorative construct, a decorative strip or the like. In the case of a panel or construct, clips or clasps are used for engaging the cuff about the throat of the shoe. In the case of a decorative strip, a novel use of magnetic fasteners is disclosed. | 0 |
This invention was made with United States Government support under contract no. DAAK60-89-C-1033 awarded by U.S. Army Natick RD&E Center. The Government has certain rights in the invention.
This is a division of application Ser. No. 08/225,464 filed Apr. 8, 1994 now U.S. Pat. No. 5,582,892.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to dimensionally stable composite articles in which polytetrafluoroethylene fibrils entrap particulate. The dimensional stability is imparted by mechanically compacting the composite articles.
2. Description of Related Art
Composite articles in which polytetrafluoroethylene (PTFE) fibrils entrap particulate have been well known for some time. Because these articles hold a large amount of particulate in a relatively small amount of fibrils (i.e., the article can be up to about 98 weight percent particulate), these articles can be thought of as a sheet of particles. Depending on the particles used, such sheets (or shapes cut therefrom) can be used in a wide variety of applications including separations, extractions, reactions, and provision of fouling/corrosion protection to marine structures.
One of the few limitations on these articles is that they tend to shrink, especially in the down-web direction (i.e., the direction of machining). This is believed to be due to the tendency of the PTFE fibrils to return to their original, coiled condition upon application of thermal or mechanical stress. This tendency can result in these articles changing shape during use, e.g., from circular to elliptical.
Eliminating this tendency to shrink without affecting the ability to confine large amounts of particulate within a relatively small area is highly desirable. One approach is set forth in assignee's copending application U.S. Ser. No. 08/179,313 wherein reinforcing means (e.g., screen or scrim) is embedded in the article. Although effective, the reinforcing means can limit the use of the articles to those applications where such a means will not interfere with the desired end use. The production of a dimensionally stable web that does not contain such a reinforcing means is potentially of great value.
SUMMARY OF THE INVENTION
Briefly, the present invention provides a composite article comprising a PTFE fibril matrix with particles entrapped therein, the article having been mechanically compacted so that, upon being subjected to thermal and/or mechanical stress, it retains at least 20% more of its longitudinal dimension than it did upon being subjected to thermal and/or mechanical stress before being mechanically compacted.
In another aspect, the present invention provides a disk, for use in solid phase extraction or reaction applications, that has been cut from a composite article comprising a fibrillated polytetrafluoroethylene matrix and sorptive particles entrapped therein, the article having been mechanically compacted so that the article, upon subjection to thermal and/or mechanical stress, retains at least 20% more of its longitudinal dimension than it did upon being subjected to thermal and/or mechanical stress before being mechanically compacted.
In a still further aspect, the present invention provides a method of making a composite web that is substantially dimensionally stable comprising the steps:
a) providing a web comprising a PTFE fibril matrix with particles entrapped therein; and
b) mechanically compacting the web and, optionally, cutting the web to provide an article therefrom.
Unless otherwise indicated, the following definitions will apply in this application:
"mechanical compaction" means the application of mechanical stress to a sheet-like article so as to preshrink that article; and
"longitudinal compaction" means feeding a sheet-like article, in the same direction as it was last processed during production, into a working zone of a compacting device wherein the velocity of the article as it is fed into the working zone is greater than the velocity of the article as it exits the working zone.
When subjected to thermal or mechanical stress, mechanically compacted particle-loaded fibrillated PTFE webs retain at least 20% more, preferably at least 50% more, and most preferably 75% more, of their longitudinal dimension upon being subjected to thermal or mechanical stress than do untreated webs. Where an article produced from a mechanically compacted particle-loaded PTFE fibril web must undergo strenuous handling or treatment, it tends to retain its initial shape.
The particle-loaded webs of the present invention confine a large amount of particles in a relatively small surface area. They can be thought of as "sheets of particles" since the amount of PTFE can be as low as 2 or 3% (by wt.), although amounts between 5 and 30% (by wt.) are preferred. In use, the PTFE fibrils of the webs are inactive toward the chemical species on which the particles are acting. Nevertheless, by mechanically compacting these webs, they retain more (e.g., at least 20% more) of their longitudinal dimension upon subjection to thermal and/or mechanical stress than do untreated webs. That such an article (i.e., a "sheet of particles") should be less prone to shrink after being mechanically compacted is quite surprising and unexpected. Nevertheless, reduction or even elimination of the tendency of these articles to shrink is observed.
Depending on the particulate used, articles of the present invention can be used in a variety of applications including solid phase extraction, solid phase reaction, and sorption of toxic and/or hazardous materials. Advantageously, those articles with a predetermined shape (e.g., a liner in article of clothing) can be later worn or treated (e.g., cleaned, laundered, etc.) without losing that shape. A dimensionally stable particle-loaded PTFE web without such an embedded reinforcing means is highly desirable.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
To produce the fibrillated PTFE web of the present invention, an aqueous PTFE dispersion is used. This milky-white dispersion contains about 25 to 70% (by wt.) of minute PTFE particles suspended in water. A major portion of these PTFE particles range in size from 0.05 to about 1.5 μm. Commercially available aqueous PTFE dispersions may contain other ingredients such as surfactants and stabilizers which promote continued suspension. Examples of such commercially available dispersions include Teflon 30, Teflon 30B, and Teflon 42 (E.I. DuPont de Nemours Chemical Corp.; Wilmington, Del.). Teflon 30 and Teflon 30B contain about 59 to 61% (by wt.) PTFE solids and about 5.5 to 6.5% (by wt., based on the weight of PTFE resin) of a non-ionic wetting agent, typically octylphenyl polyoxyethylene or nonylphenyl polyoxyethylene. Teflon 42 contains about 32 to 35% (by wt.) PTFE solids and no wetting agent, although it does contain a surface layer of organic solvent to prevent evaporation.
The composite web comprising fibrillated PTFE preferably is prepared as described in any of U.S. Pat. Nos. 4,153,661, 4,460,642, and 5,071,610, the processes of which are incorporated herein by reference, by blending the desired particulate into the aqueous PTFE emulsion in the presence of sufficient lubricant to approach, meet, or preferably exceed the sorptive capacity of the solids yet maintain a putty-like consistency. This putty-like mass is then subjected to intensive mixing at a temperature between 0° and 100° C., preferably between 40° and 100° C., to cause initial fibrillation of the PTFE particles. Thereafter, the putty-like mass is repeatedly and biaxially calendered, with a progressive narrowing of the gap between the rollers, until shear causes the PTFE to fibrillate and enmesh the particulate and a layer of desired thickness is obtained. Removal of any residual surfactant or wetting agent by organic solvent extraction or by washing with water after formation of the sheet article is generally desirable. The resultant sheet is then dried. Such sheets generally have thicknesses in the range of 0.05 to 10 mm, preferably in the range of 0.1 to 1 mm, most preferably in the range of 0.1 to 0.5 mm.
If a web with multiple particulate layers is desired, the component layers themselves are placed parallel to each other and calendered until they form a composite where the PTFE fibrils of the separate layers are entwined at the interface of adjacent sheets. Multilayer webs preferably have thicknesses in the range of 0.1 to 10 mm.
The void size and volume within such a web can be controlled by regulating the lubricant level during fabrication as described in U.S. Pat. No. 5,071,610. Because both the size and the volume of the voids can vary directly with the amount of lubricant present during the fibrillation process, webs capable of entrapping particles of various sizes are possible. For example, increasing the amount of lubricant to the point where it exceeds the lubricant sorptive capacity of the particulate by at least 3% (by wt.) and up to 200% (by wt.) can provide mean void sizes in the range of 0.3 to 5.0 μm with at least 90% of the voids having a size of less than 3.6 μm. This process can be used to create a web with one or more kinds of particles enmeshed therein. The PTFE which forms the web within which particulate is to be trapped can be obtained in resin emulsion form wherein the PTFE and lubricant are already pre-mixed (e.g., Teflon™ 30 or 30B, available from DuPont Corp.). To this emulsion can be added additional lubricant in the form of water, water-based solvents such as a water-alcohol solution, or easily removable organic solvents such as ketones, esters, and ethers, to obtain the aforementioned desired proportion of lubricant and particulate.
Particles of all shapes can be used in such a matrix. Average diameters of particles useful when the matrix comprises PTFE fibrils are within the range of 0.1 to 250 μm, more preferably within the range of 0.1 to 100 μm, and most preferably within the range of 1 to 10 μm. These particles can be of regular or irregular shape. They can even take the shape of reds or whiskers. The enmeshing fibrils retain the enmeshed particulate, by entrapment or adhesion, within the matrix, and the enmeshed particles resist sloughing.
As one skilled in the art will note, a wide variety of particulate meets these conditions and the type of particulate to be used in a given application will depend only on the desired end use of the web. Examples of particulate useful in the present invention include, but are not limited to, those listed in U.S. Pat. Nos. 4,810,381, 5,071,610, and 5,238,621 as well as those species of copper in solid form which are capable of producing aqueous copper ions, such as oxides of copper and copper particles, organotin compounds, zinc salts, encapsulated sodium nitrite, certain amines, combinations of a metal whose oxidation potential is greater than that of iron and a salt of that metal comprising that metal and an appropriate anion (such as zinc/zinc chromate), antibiotics such as oxytetracycline that can be encapsulated (e.g., in polyurea), enzymes that interfere with the ability of marine organisms to attach to marine substrates and that can be covalently bonded to polyazlactone supports such as beads, activated carbon, silica, derivatized silica, intercalated styrene divinyl-benzene, ion exchange resins, chitosan, and chitin. The particulate (or combination of particulate) chosen will depend on the end application. Even fragile materials (e.g., biological cells) can be incorporated into fibrillated PTFE webs by means of the process described above (see U.S. Pat. No. 4,722,898, the teaching of which is incorporated herein by reference), so the scope of particulate theoretically useful in the present invention is extremely broad. Those skilled in the art will recognize which particulate may be useful for a given end use application.
Where an article of the present invention is to be used for sorptive or solid phase extraction or reaction purposes, useful particulate includes activated carbon, silica, derivatized silica, zirconia, derivatized zirconia, intercalated styrene divinylbenzene, ion exchange resins, crown ether ligands bonded through linking groups to inorganic substrates (in the form of particles), chitosan, and chitin. Other useful particles include those that can be coated with an insoluble sorbent material or that can be derivatized to provide an insoluble sorbent layer. Some of the most useful particulate includes activated carbon and derivatized silica. Of the activated carbons, Maxsorb™ high surface area active carbon Kansai Coke & Chemical Co. Ltd.; Amagasaki City, Japan) and Renoves™ M30 activated mesocarbon microbeads (Osaka Gas Chemical Co.; Osaka, Japan) are particularly preferred, especially where the article is to be a protective garment (e.g., one that will be used or worn in an environmentally or toxicologically hazardous area).
Depending on the particular end use, adjuvant particles might also be incorporated in the fibrillated PTFE matrix. Pigment and other adjuvant particles with average diameters in the same ranges as listed previously with respect to active particulate can be included. Representative examples of useful pigments include carbon, copper phthalocyanine, taconite, zinc oxide, titanium dioxide, and ferric oxide. Such pigment particles can be included as part of an otherwise reactive layer or as a separate layer which then can be calendered with reactive layers to form a multilayer composite. Other adjuvants which can be incorporated into the fibrillated PTFE web include silica, diffusion modifiers, bioactivity intensifiers, and ultraviolet radiation blockers. When present, such adjuvants can comprise from more than 0 to 95% (by wt.), preferably from more than 0 to 50% (by wt.), and most preferably from more than 0 to 15% (by wt.) of the sheet article.
The sheet article of the present invention preferably comprises active (i.e., non-adjuvant) particulate in an amount of at least 10% (by wt.), more preferably comprises active particulate in an amount of at least 50% (by wt.), and most preferably comprises active particulate in an amount of at least 70% (by wt.). The sheet article can comprise particulate in an amount up to 97 or 98% (by wt.), although particulate amounts in the range of 90 to 95% (by wt.) tend to produce more stable webs. High active particulate loading is desirable to extend the useful life of the web.
Such highly-loaded webs can be thought of as sheets of particles. A large amount of particulate is confined to a defined area by means of a very small amount of fibrils. In use, the fibrils are inactive toward the chemical species to be acted upon. In other words, the species acts as if it were encountering a large mass of unenmeshed particles rather than a particle-fibril matrix.
Once a fibrillated PTFE web with particulate entrapped therein is made, it is mechanically compacted. This can be accomplished by a variety of means including mechanical crumpling, tumbling, beating, etc. However, the most preferred method is longitudinal compaction. The compacting process can be performed from a few seconds up to several hours or more. The web need not be stretched before it is compacted.
In the longitudinal compaction process, the web is fed longitudinally into a compacting device so that the velocity of the web is greater as it enters the working zone of the device (i.e., where the device intimately contacts the web) than it is as it exits that zone. Any device with this characteristic can satisfactorily treat the above-described webs. Examples of devices and/or processes that will produce this effect include those described in U.S. Pat. Nos. 2,522,663, 2,761,370, 2,765,513, 2,765,514, 3,220,056, 3,235,933, 3,426,405, 3,452,409, 3,681,819, 3,810,280, 3,869,768, 4,142,278, 4,241,478, 4,562,627, 4,882,819, 5,012,562, 5,016,329, and 5,060,349, the teachings of which are incorporated herein by reference.
Two particularly useful processes are those described in U.S. Pat. Nos. 4,882,819 (wherein compaction is accomplished by two rollers) and 5,060,349 (wherein compaction is accomplished by a retarding surface in combination with a roller). In both of these processes, a rough-surfaced feed roller imtimately contacts the particle-loaded PTFE web and controls its speed (i.e., generally from 3 to 61 m/min) as it enters the nip formed by, respectively, the second roller (which turns at a slower velocity--e.g., 5 to 50% slower--than does the feed roller) or the retarding surface (e.g., a fixed rigid or flexible blade). When the web reaches the nip (i.e., the working zone), its velocity suddenly decreases. In other words, the velocity of the web as it leaves the working zone is less than that as it enters the working zone. The loss of momentum of the web as it enters the working zone, in combination with the shear force produced at the conjunction of the feed roller and either the second roller or the retarding surface, is the compacting force that shrink treats the web.
Application of heat to the web before, during, and/or after mechanical compaction can further assist in the preshrinking of the web. The compacting process can be performed at temperatures from 40° C. to 200° C., preferably from 50° C. to 180° C. The length of the compacting process generally remain about the same whether or not heat is used.
Another way to preshrink the web articles of the present invention that involves the application of heat is a method known as "heat-crumple-heat". A sample of predetermined measurement is optionally die-cut from a web. The sample (or the web itself) is heated in a closed oven, e.g., Blue M™ oven (General Signal Corp.; Blue Island, Ill.), set at about 150° C. for about an hour at ambient humidity (i.e., about 40-50% relative humidity) and atmospheric pressure (about 1 atm). The sample is removed and cooled. Next, the sample is crumpled into a tight ball before being smoothed out to an approximately flat state. Finally, the sample is reheated for about an hour at 150° C., as described previously. After cooling, the sample is removed.
The "heat-crumple-heat" process can also be used in conjunction with the aforementioned longitudinal compaction methods.
The mechanical compaction produced by any of these processes results in many changes to the web. Most obvious among these are in the thickness and length of the treated web (i.e., the web gets fatter and shorter). These effects tend to be linked in a way such that the volume of the web is conserved. The width of the web tends to remain about the same after treatment, although some treated webs gain or lose a fraction of their width. Additionally, the volume of the web also remains fairly constant. At least with respect to longitudinal compaction, this latter effect is somewhat surprising because knitted fabrics similarly treated become more dense. This lack of change in density might be due to the particles in the web being so closely packed that they resist any compressive force and do not deform.
Perhaps most important among these changes, however, is reduction in stress stored in the PTFE fibrils. The process used to make the webs creates fibrils by passing the PTFE-particle mixture through repeated nip roll treatments. These passes cause the particles to flow relative to one another, primarily in the machine (i.e., longitudinal) direction. The particles interact with the PTFE fibrils in a manner that causes the fibrils to stretch and be drawn out. As a web is processed in a particular direction, with concomitant caliper reduction, the fibrils are stretched in that direction and increasing amounts of stress are stored in the web. This stress imparts to the fibrils a desire to "pull back" to their pre-machined condition (i.e., shrink) when subjected to mechanical and/or thermal stress.
This tendency to shrink becomes of paramount concern where a strong web is desired such as, for example, the lining of a protective garment with a manufacturing specification that the garment be able to resist water penetration up to a pressure of two atmospheres. The extreme processing necessary to provide a web from which such a lining can be cut imparts a level of stress to the fibrils such that they have an even greater tendency to shrink back to their original form. This can result in unacceptable deformity of the web.
When such a web is mechanically compacted, however, the particles and fibrils rearrange in way so that much (if not most) of the longitudinal stress is relieved. This rearranging probably occurs by both linear and rotational motion of the particles. The relieved stress is believed to be stored in the z-direction fibers. This theory is consistent with the observation that webs tend to increase in thickness after being treated.
A treated web will retain at least 20% more, preferably at least 50% more, and most preferably 75% more, of its longitudinal dimension after being subjected to thermal or mechanical stress than a non-compacted web. This result is surprising because, for most purposes, these webs act as sheets of particles. In other words, the fibrils do no more than hold the particles in place. Mechanical compaction treats the fibrils so that their tendency to retreat to their original shape (i.e., a rolled-up ball) is minimized.
If a "preshrunk" article of a particular shape is desired, it can be cut from a web that has been mechanically compacted. An example of such an article is a disk useful in solid phase extraction and reaction applications that comprises sorptive particulate such as silica, ion exchange resins, or any of the other sorptive particles mentioned previously. Another example is a garment, garment liner, or other portion thereof.
The composite articles (i.e., treated webs) of the present invention are useful in the same applications as are the untreated webs. Some examples include solid phase reaction or extraction media (e.g., disks useful in extraction and separation devices) and catalyst supports. Advantageously, the articles of the present invention retain their shape even after the application of thermal and/or mechanical stress thereto.
Objects and advantages of this invention are further illustrated by the following examples. The particular materials and amounts thereof, as well as other conditions and details, recited in these examples should not be used to unduly limit this invention.
EXAMPLES
Example 1
Preparation of an Activated Carbon-Loaded Web
Using the general procedure described in U.S. Pat. No. 4,153,661, a mixture of 2.39 kg of Teflon™ 30B, a 58.9% solids-in-water emulsion of PTFE (DuPont de Nemours Co.; Wilmington, Del.), was gently stirred into 3.59 kg of 54° C. deionized water. This mixture was added to 7.79 kg wet AX-21 activated carbon (Anderson Development Co.; Adrian, Mich.) in a mixer and the slurry was stirred for about 15 seconds.
The resulting puny-like mass was calendered at a roll speed of 3 m/min between rollers heated to 54° C. and set 5 mm apart. After each pass, the web was folded into three layers and rotated 90° and recalendered. This was done twelve times. Thereafter, the web was passed through takedown rolls with a gap of 3.54 mm. After each pass, the gap was narrowed by about 35% of its width until the web had a thickness of 0.64 mm.
This thin web was cut into 87.6 cm-long sheets. These sheets were placed on each other and the stack was passed through takedown rolls set at 0.7×the thickness of the stack. After each pass, the roll width was decreased to 0.7×of the measured web thickness until a final web thickness of 0.2 mm was attained. This thin web was taken up on a cylindrical roll and dried at 22° C. for about 24 hours.
Example 2
Heat-Crumple-Heat Process
Samples cut from the web of Example 1 were mechanically compacted by a heat-crumple-heat process described hereinbelow.
A number of samples were die-cut by hand using a steel rule die and mallet. The samples were heated at about 150° C., cooled, and measured in both the crossweb and down-web directions. The samples were then hand crumpled and held tightly for about 10 sec and smoothed to an approximately flat state. The samples were then reheated for about an hour at 150° C., cooled, and measured in both the cross-web and downweb directions to give the final shrinkage. The thickness of each sample was also measured.
Example 3
First Type of Longitudinal Compaction
Samples (3.05 m×5.08 m) cut from the web of Example 1 were passed through a Tube-Tex™ C2000 compactor (Tubular Textile Machinery; Lexington, N.C.). Each sample was fed at 4.57 m/min into a working zone where a shoe section fit into the nip between a feed roll and a slower-turning retarding roll. The treated samples then underwent the above-described "heat-crumple-heat" process so as to compare their pre- and post-longitudinal compaction characteristics, the results of which are compiled in Table I. (The percentage of PTFE in each of the samples was 29%.)
TABLE I__________________________________________________________________________Treatment with Tube-Tex ™ C2000 Compactor AS MADE AFTER TREATMENT Downweb CONDITIONS Downweb Particle length Roll Speed lengthSample loading Thickness change Temp. differential Thickness changeNo. (g/m.sup.2) (mm) (%)* (°C.) (%) (mm) (%)*__________________________________________________________________________1 134 0.30 -4.96 121 30 0.33 -4.22 128 0.33 -12.61 121 30 0.33 -9.03 121 0.30 -9.30 121 30 0.30 -3.94 128 0.33 -14.00 121 30 0.33 -10.95 145 0.30 -9.13 132 40 0.38 1.06 127 0.30 -8.96 66 40 0.36 -2.27 171 0.30 -9.74 132 50 0.46 4.48 123 0.30 -7.57 66 50 0.30 -4.4__________________________________________________________________________ *As measured after the heatcrumple-heat process described above.
The data from Table I show that the heat-crumple-heat process changes, and longitudinal compaction further changes, the way fibrillated PTFE webs react to mechanical and/or thermal stress.
Example 4
Second Type of Shrink Prevention
Using the procedure described in Example 2, untreated samples (3.05 m×5.08 m) were compared with samples that were (1) heat treated by placing the web on a continuous belt, driven at 1.8 m/min, that passed through a 30.5 m oven at 171° C. and then (2) passed at 4.57 m/min through a Micrex™ Microcreper (Micrex Corp.; Walpole, Mass.) where a feed roll (171° C.) carried each sample into a flexible retarder where it was compacted. A comparison of the sample measurements is shown below in Table II. (Each of the percentages is relative to the untreated sample.)
TABLE II__________________________________________________________________________Treatment with Micrex ™ Microcreper Change Basis Wt.Sample Change in Length (%)* in Width (%)* Thickness (g/m.sup.2)No. A B C A B C A B C B C__________________________________________________________________________1 -4.93 -6.67 -1.16 2.03 2.61 2.61 0.28 0.36 0.39 124 1542 -10.43 -8.41 -1.45 2.90 1.16 1.16 0.25 0.37 0.54 150 1903 -6.09 -8.70 2.32 2.72 1.16 2.90 0.25 0.37 0.51 152 2004 -4.64 -7.54 1.74 4.35 4.06 2.90 0.22 0.37 0.47 153 1645 -8.99 -10.72 -4.35 4.06 3.77 3.19 0.23 0.33 0.46 103 1576 -9.57 -14.20 -4.35 3.19 2.90 2.61 0.22 0.35 0.50 122 1907 -17.68 -10.72 -4.35 4.64 1.74 2.61 0.23 0.34 0.56 126 175__________________________________________________________________________ *As measured after the heatcrumple-heat process described in Example 2. A = As made (comparative) B = After heat treatment C = After longitudinal compaction
As can be seen from both Table I and Table II, webs that have been compacted shrink at least 20% less, preferably at least 50% less, and most preferably at least 75% less, than untreated webs. Some treated webs even expand in the downweb direction.
The high pressure hydrostatic resistance (HPHR) of some of these and other samples was measured both before and after longitudinal compaction. Some increase in the HPHR was observed in most of the samples, although the magnitude of the increases were not so great so as to make the samples unusable for the purposes for which they would typically be used.
Various modifications and alterations which do not depart from the scope and spirit of this invention will become apparent to those skilled in the art. This invention is not to be unduly limited to the illustrative embodiments set forth therein. | A mechanically compacted composite article comprising a PTFE fibril matrix that entraps particles retains more of its longitudinal dimension, when subjected to mechanical and/or thermal stress, than a similar but non-mechanically compacted article. A method of making a particulate loaded PTFE fibril web is disclosed, the method including biaxial calendaring to form a sheet or sheet laminate, and machanically compacting the sheet or sheet laminate. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is related to my application Ser. No. 10/007,712, filed Nov. 13, 2001, now U.S. Pat. No. 6,575,380, issued Jun. 10, 2003. This application is also related to my pending application Ser. No. 10/626,910, filed Jul. 25, 2003. This application is also related to, and claims the benefit of, my Provisional Application No. 60/416,086, filed Oct. 5, 2002.
FIELD OF THE INVENTION
[0002] This invention relates to sprinkler systems commonly used for sprinkling lawns or other landscaped areas. More particularly, it relates to installation techniques for sprinkler systems and to spacer guides for positioning sprinkler heads.
BACKGROUND OF THE PRIOR ART
[0003] Typical sprinkler systems used for lawns and other landscaped areas include water supply lines which are placed below ground and extend from a main supply pipe to each sprinkler head. The sprinkler head extends upwardly to the upper surface of the ground. Typical sprinkler heads are of the “pop-up” style which extend upwardly above the grass when pressure is applied to the water in the supply line, and then the sprinkler head retracts when it is no longer in use. The top of the sprinkler head remains exposed at ground level.
[0004] In some installations, the sprinkler head is connected to the water supply pipe with a flexible pipe. Although this enables the installer to more easily position the sprinkler head in a desired place, the flexible pipe provides little, if any, support to the sprinkler head (either lateral or vertical support). As a result, when soil is filled in around the sprinkler head, the sprinkler head can tilt to one side or the other, and the sprinkler head can also sink downwardly. When the sprinkler head is too close to a sidewalk, curb or other such object, the spinning metal blade of an edger can irreparably damage any sprinkler head which is too close to sidewalk, curb, etc. Then the sprinkler head must be replaced, at considerable time and expense.
[0005] U.S. Pat. No. 4,146,181 (Soos), U.S. Pat. No. 5,678,353 (Tsao et al), U.S. Pat. No. 6,186,416 (Jones), and D410,731 (Bowman et al.) describe various types of sprinkler head guards, grass guards and mats for use on or around sprinkler heads. However, there has not heretofore been provided a sprinkler spacer of the types described in the present invention.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention there are provided improved sprinkler head spacers for supporting sprinkler heads in lawns or other landscaped areas. When the spacers are attached to sprinkler heads (e.g. during installation in the ground), the spacers prevent sprinkler heads from being positioned too close to a sidewalk, curb, etc. The spacers can be attached to sprinkler heads in a number of different manners, and the spacers are adapted to fit onto sprinkler heads of different diameters.
[0007] In one embodiment, the sprinkler spacer comprises:
[0008] (a) a spacer body member having first and second lateral edges;
[0009] (b) attachment means carried by said body member for attaching said body member to said sprinkler;
[0010] wherein the attachment means is detachably mounted to the body member.
[0011] The attachment means can comprise a pair of opposing spring clips, for example, which can be attached to the spacer body (e.g. by means of raised ribs or tabs on the spring clips which fit into complementary slots in the spacer body).
[0012] In another embodiment, the spacer system comprises two body members which are hinged together. Each body member includes a spring finger portion. The body members are further connected by a length-adjustable rod which controls the spacing between the respective finger portions of the two body members.
[0013] Other features and advantages of the spacer system of this invention will be apparent from the following detailed description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] [0014]FIG. 1 is a plan view of one embodiment of spacer system of the invention;
[0015] [0015]FIG. 2 is a plan view of another embodiment of a spacer system of the invention;
[0016] [0016]FIG. 3A is a plan view of another embodiment of a spacer body portion;
[0017] [0017]FIG. 3B is a front elevational view of an attachment member adapted to connect to the spacer body portion of FIG. 3A;
[0018] [0018]FIG. 4 is a side elevational view of the spacer system of FIG. 1;
[0019] [0019]FIG. 5 is a plan view of yet another embodiment of a spacer system of the invention;
[0020] [0020]FIG. 6 is a plan view of a further embodiment of a spacer system of the invention;
[0021] [0021]FIG. 7 is a perspective view showing a spacer body attached to a sprinkler;
[0022] [0022]FIG. 8 is a perspective view showing a depth gauge which can be attached to a spacer body; and
[0023] [0023]FIG. 9 is a perspective view showing the depth gauge of FIG. 8 attached to the spacer body of FIG. 7, prior to the spacer body being attached to a sprinkler.
DETAILED DESCRIPTION OF THE INVENTION
[0024] In FIGS. 1 and 4 there is shown one embodiment of a spacer system 10 of the invention comprising a spacer body portion 12 and a pair of opposing spring finger clip members 14 . Each spring clip finger includes an enlarged end 14 A which is slidably received and retained in a complementary shaped slot 12 A in body portion 12 . This design enables the spacer body to be used with different sizes of spring finger clips. For example, when using large diameter sprinklers, appropriately sized spring finger clips can be attached to the spacer body to accommodate the large sprinkler body. Conversely, if a small diameter sprinkler is used, then smaller spring finger clips can be used on the spacer body.
[0025] Preferably the body portion comprises spaced-apart ribs with vertical openings between them, as shown in the drawings, to enable water and fertilizer, etc. to pass through the spacer after installation. The body portion 12 preferably includes edges 13 A, 13 B and 13 C which are at angles to each other (e.g. edges 13 A and 13 C may be at 45 degrees relative to edge 13 B). The presence of these angled edges enables the spacer to be positioned next to sidewalks, curbs, etc. to maintain a predetermined spacing between the sprinkler head and the concrete material. The presence of these angled edges also enable the spacer to be positioned in a corner (e.g. where two sidewalks meet, or where a sidewalk meets a curb) so that one such edge abuts against the edge of one sidewalk and the other such edge abuts against the edge of another sidewalk (or curb), regardless of the particular angle between the two sidewalks or sidewalk and curb, etc.
[0026] Preferably the spacer body also has attached to it one or more vertical tabs 15 having a length of about 1.5 inches. The presence of the tab(s) is to assure that the spacer body is properly positioned about 1.5 inches below the upper end of the sprinkler body. This arrangement assures that the spacer body will not be impacted by the blade of a metal edger used along a sidewalk, curb, etc. There may be a vertical tab 15 extending upwardly from the upper surface of the spacer and another vertical tab extending downwardly from the lower surface of the spacer. The presence of two such tabs makes the spacer symmetrical (so that it cannot be clipped or attached to a sprinkler upside down). Whichever way the spacer is attached to a sprinkler, one of the vertical tabs will be oriented upwardly. If desired, the tab (depth gauge) may be separate from the spacer body so that the depth gauge is vertically adjustable. This enables the spacer to be positioned lower or higher relative to the sprinkler, as desired.
[0027] Preferably, the spacer body also includes a stake receiver 16 having resilient legs or arms 16 A. In order to provide additional lateral stability to a sprinkler head, a vertical stake can be inserted vertically through the receiver 16 (between arms 16 A) and into the ground when the sprinkler is installed. The length and design of such a stake may vary. Once installed, the spacer and stake assembly holds the sprinkler in place so that the complete irrigation system can be turned on for a pressure test before the sprinkler trenches have been filled. This enables the sprinklers and pipes to be checked for leaks, adjustment, etc. The spray coverage can also be checked to assure there are no dry areas. Necessary adjustments or replacement of sprinklers can be made as required. This a huge advantage and saves a tremendous amount of time because any leaks or other problems with the irrigation system can be corrected before the trenches are filled. The stakes and spacers hold and support the sprinklers in their intended position so that the irrigation system can be fully tested.
[0028] In FIG. 2 there is shown another spacer system utilizing the same spacer body 12 but different types of opposing spring finger clips 17 . As shown, these spring fingers each include an enlarged rib 17 B for sliding engagement in a slot 12 A in the spacer body 12 . Each spring finger also includes an inner end 17 A which extends past the point where the rib 17 A is located in order to provide additional support and rigidity to the spring finger clip mounting.
[0029] In FIGS. 3A and 3B there is shown another spacer system comprising a spacer body 22 A (top plan view) having an inner lateral edge 25 and outer edges 23 A, 23 B and 23 C. On edge 25 there are provided a plurality of spaced-apart, projecting tab members 24 . On spring clip finger portion 22 B (rear elevational view) there are a corresponding plurality of recessed openings or sockets 24 A which are adapted to slidably receive the tab members 24 and thereby hold the spring clip finger portion to the spacer body.
[0030] In FIG. 5 there is shown another embodiment of spacer system 26 comprising complementary shaped body portions 28 which are hinged together intermediate their ends with pin 27 . Each body portion includes a spring clip finger 28 A. At the opposite end of the spacer there is a length-adjustable connector. Elongated receiver connector 29 is fastened to one body portion 28 by means of pin 29 B. The connector 29 includes a plurality of longitudinally spaced-apart recessed areas or sockets 29 A. Elongated connector rod 30 is fastened to the other body member 28 by means of pin 30 B. The opposite end of connector rod 30 includes an enlarged end 30 A which is adapted to be received in a desired one of the recessed areas or sockets 29 A. Depending upon which of the sockets 29 A the enlarged end 30 A is received in, the spacing between the spring finger clips 28 A will be different so as to accommodate sprinkler heads of different diameters. As shown, this spacer system may also include a stake receiver 16 of the type described above which enables an elongated stake to be inserted into, and held by, the receiver 16 . Then the stake will extend downwardly from the spacer to provide lateral and vertical support to the sprinkler held by the fingers 28 A.
[0031] In FIG. 6 there is shown another spacer system 32 of the invention comprising spacer body member 33 and a pair of spring clip fingers 34 A. The fingers 34 A are each pivotably attached to the body portion 33 by means of pins 35 . At the inner end 34 B of each finger there is secured a threaded receiver which is connected to threaded rod 36 . A centrally located rotating knob 37 on rod 36 enables the rod 36 to be easily rotated so as to cause the respective fingers 34 A to be moved selectively closer together or further apart in order to accommodate sprinkler heads of different diameters.
[0032] [0032]FIG. 7 is a perspective view showing a spacer body 40 of the invention with spring finger clip members 14 attached to one edge of the spacer body. Each spring clip finger includes an enlarged end 14 A which is slidably received and retained in a complementary shaped slot in the body 40 , as shown. The spring clip fingers are adapted to attach the spacer body to a sprinkler 50 , as illustrated.
[0033] [0033]FIG. 8 is a perspective view of a depth gauge 42 comprising an elongated strip 43 having two spaced-apart tabs 44 extending outwardly from each side of the strip, as shown. The spacing between each set of two tabs is only slightly greater than the thickness of spacer body 40 such that the spacer body can be slidably received between the tabs and held there with frictional engagement. This is illustrated in FIG. 9 where the depth gauge is attached to spacer body 40 and then spacer body 40 is attached to the sprinkler. The depth gauge prevents the spacer body from sliding too far upwardly on the sprinkler (i.e. the depth gauge assures that the spacer body will be positioned a minimum distance below the top of the sprinkler head). Typically, the depth gauge can be composed of plastic and produced by injection molding techniques. Preferably the tab members 44 are disposed in the center of the depth gauge, as shown, so that the gauge is symmetrical and can be attached to the spacer body with either end of the depth gauge extending upwardly. Of course, it would be possible to position the tabs closer to one end of the gauge, if desired, so as to have a smaller distance between the tabs and one end of the strip.
[0034] Other variants are possible without departing from the scope of this invention. | Sprinkler head spacer systems for preventing a sprinkler head from being positioned too close to a sidewalk or curb. The spacers include a body and attachment fingers for attachment of the spacers to a sprinkler. Various styles are disclosed, including some in which the fingers are detachable from the body. In other versions the spacing between the fingers is adjustable to accommodate sprinklers of different diameters. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
The invention relates to novel methods, compositions, and apparatuses for improving the effectiveness of froth flotation beneficiation processes. In a beneficiation process, two or more materials which coexist in a mixture (the fines) are separated from each other using chemical and/or mechanical processes. Often one of the materials (the beneficiary) is more valuable or desired than the other material (the gangue).
As described for example in U.S. Pat. Nos. 4,756,823, 5,304,317, 5,379,902, 7,553,984, 6,827,220, 8,093,303, 8,123,042, and in Published US Patent Applications 2010/0181520 A1 and 2011/0198296, and U.S. patent application Ser. No. 13/687,042, one form of beneficiation is froth flotation separation. Commonly, flotation uses the difference in the hydrophobicity of the respective components. The components are introduced into the flotation apparatus sparged with air, to form bubbles. The hydrophobic particles preferentially attach to the bubbles, buoying them to the top of the apparatus. The floated particles (the concentrate) are collected, dewatered and accumulated as a sellable product. The less hydrophobic particles (the tailings) tend to migrate to the bottom of the apparatus from where they can be removed.
Two common forms of flotation separation processes are direct flotation and reverse flotation. In direct flotation processes, the concentrate is the beneficiary and the tailings are the gangue. In reverse flotation processes, the gangue constituent is floated into the concentrate and the beneficiary remains behind in the slurry. The object of flotation is to separate and recover as much of the valuable constituent(s) of the fine as possible in as high a concentration as possible which is then made available for further downstream processing steps.
Froth flotation separation can be used to separate solids from solids (such as the constituents of mine ore) or liquids from solids or from other liquids (such as the separation of bitumen from oil sands). When used on solids, froth separation also often includes having the solids comminuted (ground up by such techniques as dry-grinding, wet-grinding, and the like). After the solids have been comminuted they are more readily dispersed in the slurry and the small solid hydrophobic particles can more readily adhere to the sparge bubbles.
There are a number of additives that can be added to increase the efficiency of a froth flotation separation. Collectors are additives which adhere to the surface of concentrate particles and enhance their overall hydrophobicity. Gas bubbles then preferentially adhere to the hydrophobized concentrate and it is more readily removed from the slurry than are other constituents, which are less hydrophobic or are hydrophilic. As a result, the collector efficiently pulls particular constituents out of the slurry while the remaining tailings which are not modified by the collector, remain in the slurry. Examples of collectors include oily products such as fuel oil, tar oil, animal oil, vegetable oil, fatty acids, fatty amines, and hydrophobic polymers. Other additives include frothing agents, promoters, regulators, modifiers, depressors (deactivators) and/or activators, which enhance the selectivity of the flotation step and facilitate the removal of the concentrate from the slurry.
The performance of collectors can be enhanced by the use of modifiers. Modifiers may either increase the adsorption of collector onto a given mineral (promoters), or prevent collector from adsorbing onto a mineral (depressants). Promoters are a wide variety of chemicals which in one or more ways enhance the effectiveness of collectors. One way promoters work is by enhancing the dispersion of the collector within the slurry. Another way is by increasing the adhesive force between the concentrate and the bubbles. A third way is by increasing the selectivity of what adheres to the bubbles. This can be achieved by increasing the hydrophilic properties of materials selected to remain within the slurry, these are commonly referred to as depressants.
Frothing agents or frothers are chemicals added to the process which have the ability to change the surface tension of a liquid such that the properties of the sparging bubbles are modified. Frothers may act to stabilize air bubbles so that they will remain well-dispersed in slurry, and will form a stable froth layer that can be removed before the bubbles burst. Ideally the frother should not enhance the flotation of unwanted material and the froth should have the tendency to break down when removed from the flotation apparatus. Collectors are typically added before frothers and they both need to be such that they do not chemically interfere with each other. Commonly used frothers include pine oil, aliphatic alcohols such as MIBC (methyl isobutyl carbinol), polyglycols, polyglycol ethers, polypropylene glycol ethers, polyoxyparaffins, cresylic acid (xylenol), commercially available alcohol blends such as those produced from the production of 2-ethylhexanol and any combination thereof.
The froth must be strong enough to support the weight of the mineral floated and yet not be tenacious and non-flowing. The effectiveness of a frother is dependent also on the nature of the fluid in which the flotation process is conducted. Unfortunately contradictory principles of chemistry are at work in froth flotation separation which forces difficulties on such interactions. Because froth flotation separation relies on separation between more hydrophobic and more hydrophilic particles, the slurry medium often includes water. Because however many commonly used frothers are themselves sparingly soluble in water if at all, they do not disperse well in water which makes their interactions with the bubbles less than optimal.
Thus it is clear that there is definite utility in improved methods, compositions, and apparatuses for applying frothers in froth separation slurry. The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is “prior art” with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 CFR §1.56(a) exists.
BRIEF SUMMARY OF THE INVENTION
At least one embodiment of the invention is directed to a method of enhancing the performance of frothing agent in a froth flotation separation of slurry in a medium. The method comprises the steps of: making stable microemulsion with a frothing agent, a surfactant (optionally also with a cosurfactant) and water, and blending this microemulsion with the medium, fines, and other additives, and removing concentrate from the slurry by sparging the slurry.
The microemulsion may improve the efficiency of froth separation process. More concentrate may be removed than if a greater amount of frother had been used in a non-microemulsion form. The microemulsion may comprise a continuous phase which is water and a dispersed phase. The microemulsion as a whole by weight may be made up of: 1-99% water, blended with: 1-50% of a frother component such as an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-15% C8-C10 fatty acids, 1-30% 2-butoxy ethanol surfactant, 1-20% propylene glycol, and 1-10% potassium hydroxide.
The microemulsion as a whole by weight may be made up of: 1-99% water, blended with: 1-50% of a frother component such as an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-20% C8-C10 fatty acids, 1-30% 2-butoxy ethanol surfactant, and 1-10% potassium hydroxide.
The microemulsion as a whole by weight may be made up of: 1-99% water, blended with: 1-50% of a frother component such as an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-20% C8-C10 fatty acids, 1-30% propylene glycol, and 1-10% potassium hydroxide.
The microemulsion as a whole by weight may be made up of: 1-99% water, 1-50% of a frother component such as an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-30% 2-ethyl hexanoic acid, 1-20% 2-butoxy ethanol surfactant, and 1-10% potassium hydroxide.
The slurry may comprise an ore containing one item selected from the list consisting of: copper, gold, silver, iron, lead, nickel, cobalt, platinum, zinc, coal, barite, calamine, feldspar, fluorite, heavy metal oxides, talc, potash, phosphate, iron, graphite, kaolin clay, bauxite, pyrite, mica, quartz, sulfide ore, complex sulfide ore, non-sulfide ore, and any combination thereof
The frother may be one that would not remain in a stable emulsion state unless in a microemulsion form.
Additional features and advantages are described herein, and will be apparent from, the following Detailed Description.
DETAILED DESCRIPTION OF THE INVENTION
The following definitions are provided to determine how terms used in this application, and in particular how the claims, are to be construed. The organization of the definitions is for convenience only and is not intended to limit any of the definitions to any particular category.
“Collector” means a composition of matter that selectively adheres to a particular constituent of the fine and facilitates the adhesion of the particular constituent to the micro-bubbles that result from the sparging of a fine bearing slurry.
“Comminuted” means powdered, pulverized, ground, or otherwise rendered into fine solid particles.
“Concentrate” means the portion of fine which is separated from the slurry by flotation and collected within the froth layer.
“Consisting Essentially of” means that the methods and compositions may include additional steps, components, ingredients or the like, but only if the additional steps, components and/or ingredients do not materially alter the basic and novel characteristics of the claimed methods and compositions.
“Fine” means a composition of matter containing a mixture of a more wanted material, the beneficiary and a less wanted material, the gangue.
“Frother” or “Frothing Agent” means a composition of matter that enhances the formation of the micro-bubbles and/or preserves the formed micro-bubbles bearing the hydrophobic fraction that result from the sparging of slurry.
“Microemulsion” means a dispersion comprising a continuous phase material, substantially uniformly dispersed within which are droplets of a dispersed phase material, the droplets are sized in the range of approximately from 1 to 100 nm, usually 10 to 50 nm.
“Slurry” means a mixture comprising a liquid medium within which fines (which can be liquid and/or finely divided solids) are dispersed or suspended, when slurry is sparged, the tailings remain in the slurry and at least some of the concentrate adheres to the sparge bubbles and rises up out of the slurry into a froth layer above the slurry, the liquid medium may be entirely water, partially water, or may not contain any water at all.
“Stable Emulsion” means an emulsion in which droplets of a material dispersed in a carrier fluid that would otherwise merge to form two or more phase layers are repelled from each other by an energy barrier, the energy barrier may be higher than, as low as 20 kT, or lower, the repulsion may have a half-life of a few years. Enabling descriptions of emulsions and stable emulsions are stated in general in Kirk - Othmer, Encyclopedia of Chemical Technology , Fourth Edition, volume 9, and in particular on pages 397-403 and Emulsions: Theory and Practice, 3 rd Edition, by Paul Becher, Oxford University Press, (2001).
“Surfactant” and “Co-surfactant” is a broad term which includes anionic, nonionic, cationic, and zwitterionic surfactants, a co-surfactant is an additional one or more surfactants present with a first distinct surfactant that acts in addition to the first surfactant, to reduce or further reduce the surface tension of a liquid. Further enabling descriptions of surfactants and co-surfactants are stated in Kirk - Othmer, Encyclopedia of Chemical Technology , Third Edition, volume 8, pages 900-912, and in McCutcheon's Emulsifiers and Detergents , both of which are incorporated herein by reference.
“Sparging” means the introduction of gas into a liquid for the purpose of creating a plurality of bubbles that migrate up the liquid.
In the event that the above definitions or a description stated elsewhere in this application is inconsistent with a meaning (explicit or implicit) which is commonly used, in a dictionary, or stated in a source incorporated by reference into this application, the application and the claim terms in particular are understood to be construed according to the definition or description in this application, and not according to the common definition, dictionary definition, or the definition that was incorporated by reference. In light of the above, in the event that a term can only be understood if it is construed by a dictionary, if the term is defined by the Kirk - Othmer Encyclopedia of Chemical Technology, 5th Edition, (2005), (Published by Wiley, John & Sons, Inc.) this definition shall control how the term is to be defined in the claims.
In at least one embodiment a froth flotation separation process is enhanced by the addition to the slurry of an inventive composition. The composition comprises a frother, a solvent (such as water and/or another solvent) and one or more surfactants (optionally with one or more co-surfactants) and is in the form of a microemulsion. In at least one embodiment the frother is added in an amount that is insufficient to effectively froth the slurry on its own or only at a less than desired rate. However because it is dispersed in the form of a microemulsion the composition froths the slurry much more effectively.
The composition not only enhances the recovery of concentrate but it increases the selectivity of the bubbles increasing the proportion of beneficiary and reducing the proportion of gangue in the concentrate. While effective in many forms of beneficiation the invention is particularly effective in coal flotation.
A microemulsion is a dispersion comprising a continuous phase material, dispersed within which are droplets of a dispersed phase material. The droplets are sized in the range of approximately from 1 to 100 nm, usually 10 to 50 nm. Because of the extremely small size of the droplets, a microemulsion is isotropic and thermodynamically stable. In at least one embodiment the composition comprises materials that if dispersed in droplets larger than microemulsion size, would not be thermodynamically stable and would separate into two or more discrete phase layers. In at least one embodiment the continuous phase material comprises water. In at least one embodiment the dispersed phase material and/or the continuous phase material comprises one or more hydrophobic materials. In at least one embodiment the microemulsion is according to the description within Terminology of polymers and polymerization processes in dispersed systems ( IUPAC Recommendations 2011), by Stanislaw Slomkowski et al, Pure and Applied Chemistry Vol. 83 Issue 12, pp. 2229-2259 (2011).
In at least one embodiment the microemulsion is stable enough for storage and transport prior to being added to slurry. In at least one embodiment the microemulsion is stable for at least 1 year. In at least one embodiment because the droplets are so small hydrostatic forces that would otherwise coalesce larger droplets into phase layers actually holds the micro-sized droplets in place, thereby making the microemulsion highly stable and highly effective.
Without being limited to a particular theory of the invention and in particular to the construal of the claims, it is believed that by forming a microemulsion, the properties of the frother are fundamentally changed. One effect is that the microemulsion increases the surface area of the dispersed phase frother and thereby increases its effectiveness by increasing the number of particle-bubble interactions. This has the effect of forming more and smaller sparging bubbles than would otherwise form. These more populous and smaller bubbles more effectively adhere to concentrate and more selectively bind beneficiary material
Although some microemulsions may form spontaneously, when they form, the selection of the components thereof and their relative amounts are very critical for their formation, their final characteristics such as optical appearance, and their organoleptic and thermodynamic time-stability. Unfortunately it is quite difficult to convert a frother composition into a microemulsion. Many frothers are innately hydrophobic and will tend to coalesce and phase separate. In addition, many emulsifying agents will either not form the proper sized droplet or will inhibit the effectiveness of the frother. As a result the following microemulsion frother forming composition are surprisingly effective.
In at least one embodiment the microemulsion composition comprises: 1-99% water, blended with: 1-50% of an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-20% C8-C10 fatty acids, 1-30% 2-butoxy ethanol surfactant, 1-20% propylene glycol, and 1-10% potassium hydroxide.
In at least one embodiment the microemulsion composition comprises: 1-99% water, blended with: 1-50% of an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-20% C8-C10 fatty acids, 1-30% 2-butoxy ethanol surfactant, and 1-10% potassium hydroxide.
In at least one embodiment the microemulsion composition comprises: 1-99% water, blended with: 1-50% of an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-20% C8-C10 fatty acids, 1-30% propylene glycol, and 1-10% potassium hydroxide.
In at least one embodiment the microemulsion composition comprises: 1-99% water, 1-50% of an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol, 1-30% 2-ethyl hexanoic acid, 1-30% 2-butoxy ethanol surfactant, and 1-10% potassium hydroxide.
In at least one embodiment the composition comprises less than 32% water.
When 2-ethyl hexanol is synthesized a waste stream is produced. For example as described in Chinese Patent Publication CN 101973847 B, the waste stream could include but is not limited to, 2-ethylhexan-1-ol, alcohols C12 and higher, diols C8 to C12 and higher, alkyl ethers, alkyl esters, aliphatic hydrocarbons, pyrans C 12 H 24 O and C 12 H 22 O, aliphatic aldehydes and aliphatic acetals. Some or all of the constituents of this waste stream may be used in the inventive composition. A number of commercially available formulations of this alcohol blend are available for sale.
In at least one embodiment the composition added to the slurry contains one or more materials or is added according to one or more of the processes described in one or more of: Canadian Patent Application CA 2150216 A1, United Kingdom Patent Application GB 2171929 A, and The use of reagents in coal flotation , by Laskowski, J. S. et al., Processing of Hydrophobic Minerals and Fine Coal, Proceedings of the UBC-McGill Bi-Annual International Symposium on Fundamentals of Mineral Processing, 1st, Vancouver, B. C., Aug. 20-24, 1995 (1995), pp. 191-197.
In at least one embodiment the dosage range for the microemulsion frother in the slurry would be >0-100 ppm of active frother.
In at least one embodiment the microemulsion is applied to anyone or more of the following processes: beneficiation of ore containing: copper, gold, silver, iron, lead, nickel, cobalt, platinum, zinc, coal, barite, calamine, feldspar, fluorite, heavy metal oxides, talc, potash, phosphate, iron, graphite, kaolin clay, bauxite, pyrite, mica, quartz, and any combination thereof, sulfide ores including but not limited to copper, gold and silver, iron, lead, nickel and cobalt, platinum, zinc, complex sulfide ores such as but not limited to copper-lead-zinc, non-sulfide ores such as coal, barite, calamine, feldspar, fluorite, heavy metal oxides, talc, potash, phosphate, iron, graphite and kaolin clay, and any combination thereof.
In at least one embodiment the microemulsions form spontaneously, when the components are brought together. Provided the components are in the correct proportion, the mixture may be optically clear and/or may be thermodynamically stable. Thus, their manufacturing may be reduced to simple kneading without the need for expensive high energy mixing. Also, often microemulsions are not prone to separation or settling, which may result in their long storage stability. In at least one embodiment only gentle mixing is required to restore a microemulsion if it has been previously frozen.
Representative frothers useful in the invention include but are not limited to aliphatic alcohols, cyclic alcohols, propylene oxide and polypropylene oxide, propylene glycol, polypropylene glycol and polypropylene glycol ethers, polyglycol ethers, polyglycol glycerol ethers, polyoxyparaffins, natural oils such as pine oil an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol and any combination thereof.
Representative surfactants/co-surfactants useful in the invention include but are not limited to polyoxyalkylene homopolymers and copolymers; straight chain or branched mono and polyhydric aliphatic or aromatic alcohols, and their monomeric, oligomeric, or polymeric alkoxylates; C8-C35 fatty acid salts, unsaturated or saturated, branched or straight chain; di and tri propylene glycol; polypropylene glycol, polypropylene glycol ethers and glycol ethers, and any combination thereof.
In at least one embodiment the microemulsion is an oil-in water type microemulsion.
In at least one embodiment the microemulsion is a water-in oil type microemulsion.
In at least one embodiment the microemulsion is one or more of a: Winsor type I microemulsion, Winsor type II microemulsion, Winsor type Ill microemulsion, and any combination thereof.
The composition may be used along with or in the absence of a collector. It may be added to the slurry before, after, or simultaneous to the addition of a collector. It may be added before during or after sparging and/or beneficiation has begun. The composition may be used with or in the absence of any collector in any flotation process.
When used along with a collector, the collector may comprise at least one of the collector compositions and/or other compositions described in scientific papers: Application research on emulsive collector for coal flotation , by C. L. Han et al., Xuanmei Jishu, vol. 3 pages 4-6 (2005), The use of reagents in coal flotation , by J. S. Laskowski, Proceedings of the UBC-McGill Bi-Annual International Symposium on Fundamentals of Mineral Processing, Vancouver, BC, CIMM, Aug. 20-24 (1995), Effect of collector emulsification on coal flotation kinetics and on recovery of different particle sizes , by A. M. Saleh, Mineral Processing on the verge of the 21st Century, Proceedings of the International Mineral Processing Symposium, 8th, Antalya, Turkey, Oct. 16-18, 2000, pp. 391-396 (2000), Application of novel emulsified flotation reagent in coal slime flotation , by W. W. Xie, Xuanmei Jishu vol. 2 pp. 13-15 (2007), A study of surfactant/oil emulsions for fine coal flotation, by Q. Yu et al., Advance in Fine Particle Processing, Proc. Int. Symp. pp. 345-355, (1990), and Evaluation of new emulsified floatation reagent for coal , by S. Q. Zhu, Science Press Beijing, vol. 2 pp. 1943-1950 (2008).
In at least one embodiment at least part of the collector is at least one item selected from the list consisting of: fatty acids, fatty acid esters, neutralized fatty acids, soaps, amine compounds, petroleum-based oily compounds (such as diesel fuels, decant oils, and light cycle oils, kerosene or fuel oils), organic type collector, and any combination thereof.
In at least one embodiment the organic type collector is a sulfur containing material which includes such items as xanthates, xanthogen formates, thionocarbamates, dithiophosphates (including sodium, zinc and other salts of dithiophosphates), and mercaptans (including mercaptobenzothiazole), ethyl octylsulfide, and any combination thereof.
In at least one embodiment the collector includes “extender oil” in which at least one second collector is used to reduce the required dosage of at least one other more expensive collector.
In at least one embodiment the emulsifier comprises at least one of the surfactants described in the scientific textbook Emulsions: Theory and Practice, 3 rd Edition, by Paul Becher, Oxford University Press, (2001).
In at least one embodiment the surfactant is at least one item selected from the list consisting of: ethoxylated sorbitan esters (such as Tween 81 by Sigma Aldrich), soy lecithin, sodium stearoyl lactylate, DATEM (Diacetyl Tartaric Acid Ester of Monoglyceride), surfactants, detergents, and any combination thereof.
In at least one embodiment the following items are added to a slurry medium: fines, frother, a microemulsion forming surfactant, and optionally a collector. The items can be added simultaneously or in any possible order. Any one, some, or all of the items can be pre-mixed together before being added to the slurry medium. The slurry medium can be any liquid including but not limited to water, alcohol, aromatic liquid, phenol, azeotropes, and any combination thereof. Optionally the items can include one or more other additives.
EXAMPLES
The foregoing may be better understood by reference to the following examples, which are presented for purposes of illustration and are not intended to limit the scope of the invention. In particular the examples demonstrate representative examples of principles innate to the invention and these principles are not strictly limited to the specific condition recited in these examples. As a result it should be understood that the invention encompasses various changes and modifications to the examples described herein and such changes and modifications can be made without departing from the spirit and scope of the invention and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
Two frother microemulsion samples were prepared and tested. They were applied to a coal ore beneficiation process in various amounts and in both the presence and the absence of a collector. Their effectiveness is presented on Table 1. Yield % is a measurement of how much of the fines were removed as concentrate. Ash % is a measure of how much unwanted material was present in the concentrate when the coal was burned. The performance of the microemulsion samples were compared to the effectives of a commercially available MIBC frother and another commercially available frother (Component A).
Sample I contained 30%, frother component A being a commercially available alcohol blend, a waste stream derived from the production of 2-ethyl hexanol, 5%, commercially available fatty acid, 15%, commercially available surfactant 2-butoxy ethanol, 15%, commercially available polypropylene glycol, 31.5% water, and 3.5% potassium hydroxide (45%) solution in water.
Sample II contained 50%, frother component A being a commercially available alcohol blend, a waste stream derived from the production of 2-ethyl hexanol, 15% commercially available fatty acid, 2-ethyl hexanoic acid, 14.0%, commercially available surfactant 2-butoxy ethanol, 15.5% water, and 5.5% potassium hydroxide (45%) solution in water.
Samples 1 and 2 are examples which representative the general principle of converting any frothing agent into the form of a microemulsion and using that microemulsion as the frothing agent.
TABLE I
Active
Frother
Compo-
Dos-
Frother
nent
Recov-
Collec-
age
Frother
Dosage
Dosed
Yield
Ash
ery
tor
(g/T)
Used
(ppm)
(ppm)
%
%
%
—
0
MIBC
3.0
3.0
22.10
5.09
32.28
—
0
MIBC
5.0
5.0
32.73
6.44
47.56
—
0
MIBC
8.0
8.0
43.36
7.22
64.44
—
0
Component
3.0
3.0
22.15
5.90
32.97
A
—
0
Component
5.0
5.0
28.51
6.19
41.74
A
—
0
Component
8.0
8.0
34.67
6.31
51.39
A
—
0
Sample 1
3.0
0.9
15.51
5.91
23.12
—
0
Sample 1
5.0
1.5
29.78
6.47
44.79
—
0
Sample 1
8.0
2.4
39.00
6.76
55.62
—
0
Sample 2
3.0
1.5
36.61
6.32
54.77
—
0
Sample 2
5.0
2.5
39.00
6.56
56.83
—
0
Sample 2
8.0
4.0
42.69
6.79
62.48
Diesel
170
Component
6.0
6.0
52.10
6.67
76.13
A
Diesel
170
Sample 1
6.0
1.8
52.25
7.16
76.90
Diesel
170
Sample 2
6.0
3.0
52.94
7.33
77.14
The data demonstrates that a much smaller amount of active frother composition (as low as 20-60% or more, or even less) is required to get the same or better effects than a much larger amount of frother if the frother is added to the slurry in the form of a microemulsion.
While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. The present disclosure is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated. All patents, patent applications, scientific papers, and any other referenced materials mentioned herein are incorporated by reference in their entirety. Furthermore, the invention encompasses any possible combination of some or all of the various embodiments described herein and/or incorporated herein. In addition the invention encompasses any possible combination that also specifically excludes any one or some of the various embodiments described herein and/or incorporated herein.
The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
All ranges and parameters disclosed herein are understood to encompass any and all subranges subsumed therein, and every number between the endpoints. For example, a stated range of “1 to 10” should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, (e.g. 1 to 6.1), and ending with a maximum value of 10 or less, (e.g. 2.3 to 9.4, 3 to 8, 4 to 7), and finally to each number 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 contained within the range. All percentages, ratios and proportions herein are by weight unless otherwise specified.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto. | The invention provides methods and compositions for improving a froth flotation type separation. The method uses a microemulsion to improve the effectiveness of a frother. The improvement allows for low dosages of frother to work as well as much greater amounts of non-microemulsified frother. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to upgrading of heavy hydrocarbons such as whole heavy oil, bitumen, and the like using supercritical water.
BACKGROUND OF THE INVENTION
[0002] Oil produced from a significant number of oil reserves around the world is simply too heavy to flow under ambient conditions. This makes it challenging to bring remote, heavy oil resources closer to the markets. One typical example is the Hamaca field in Venezuela. In order to render such heavy oils flowable, one of the most common methods known in the art is to reduce the viscosity and density by mixing the heavy oil with a sufficient diluent. The diluent may be naphtha, or any other stream with a significantly higher API gravity (i.e., much lower density) than the heavy oil.
[0003] For a case such as Hamaca, diluted crude oil is sent from the production wellhead via pipeline to an upgrading facility. Two key operations occur at the upgrading facility: (1) the diluent stream is recovered and recycled back to the production wellhead in a separate pipeline, and (2) the heavy oil is upgraded with suitable technology known in the art (coking, hydrocracking, hydrotreating, etc.) to produce higher-value products for market. Some typical characteristics of these higher-value products include: lower sulfur content, lower metals content, lower total acid number (TAN), lower residuum content, higher API gravity, and lower viscosity. Most of these desirable characteristics are achieved by reacting the heavy oil with hydrogen gas at high temperatures and pressures in the presence of a catalyst. In the case of Hamaca, the upgraded crude is sent further to the end-users via tankers. These diluent addition/removal processes and hydrogen-addition or other upgrading processes have a number of disadvantages:
[0004] 1. The infrastructure required for the handling, recovery, and recycle of diluent could be expensive, especially over long distances. Diluent availability is another potential issue.
[0005] 2. Hydrogen-addition processes such as hydrotreating or hydrocracking require significant investments in capital and infrastructure.
[0006] 3. Hydrogen-addition processes also have high operating costs, since hydrogen production costs are highly sensitive to natural gas prices. Some remote heavy oil reserves may not even have access to sufficient quantities of low-cost natural gas to support a hydrogen plant. These hydrogen-addition processes also generally require expensive catalysts and resource intensive catalyst handling techniques, including catalyst regeneration.
[0007] 4. In some cases, the refineries and/or upgrading facilities that are located closest to the production site may have neither the capacity nor the facilities to accept the heavy oil.
[0008] 5. Coking is often used at refineries or upgrading facilities. Significant amounts of by-product solid coke are rejected during the coking process, leading to lower liquid hydrocarbon yield. In addition, the liquid products from a coking plant often need further hydrotreating. Further, the volume of the product from the coking process is significantly less than the volume of the feed crude oil.
[0009] A process according to the present invention overcomes these disadvantages by using supercritical water to upgrade a heavy hydrocarbon feedstock into an upgraded hydrocarbon product or syncrude with highly desirable properties (low sulfur content, low metals content, lower density (higher API), lower viscosity, lower residuum content, etc.). The process neither requires external supply of hydrogen nor must it use catalysts. Further, the process in the present invention does not produce an appreciable coke by product.
[0010] In comparison with the traditional processes for syncrude production, advantages that may be obtained by the practice of the present invention include a high liquid hydrocarbon yield, no need for externally-supplied hydrogen; no need to provide catalyst; significant increases in API gravity in the upgraded hydrocarbon product; significant viscosity reduction in the upgraded hydrocarbon product; and significant reduction in sulfur, metals, nitrogen, TAN, and MCR (micro-carbon residue) in the upgraded hydrocarbon product.
[0011] Various methods of treating heavy hydrocarbons using supercritical water are disclosed in the patent literature. Examples include U.S. Pat. Nos. 3,948,754, 3,948,755, 3,960,706, 3,983,027, 3,988,238, 3,989,618, 4,005,005, 4,151,068, 4,557,820, 4,559,127, 4,594,141, 4,840,725, 5,611,915, 5,914,031 and 6,887,369 and EP671454.
[0012] U.S. Pat. No. 4,840,725 discloses a process for conversion of high boiling liquid organic materials to lower boiling materials using supercritical water in a tubular continuous reactor. The water and hydrocarbon are separately preheated and mixed in a high-pressure feed pump just before being fed to the reactor.
[0013] U.S. Pat. No. 5,914,031 discloses a three zone reactor design so that the reactant activity, reactant solubility and phase separation of products can be optimized separately by controlling temperature and pressure. However, all the examples given in the patent were obtained using batch operation.
[0014] U.S. Pat. No. 6,887,369 discloses a supercritical water pretreatment process using hydrogen or carbon monoxide preferably carried out in a deep well reactor to hydrotreat and hydrocrack carbonaceous material. The deep well reactor is adapted from underground oil wells, and consists of multiple, concentric tubes. The deep well reactor described in the patent is operated by introducing feed streams in the core tubes and returning reactor effluent in the outer annular section.
[0015] Among other factors, the present invention is based on experimental findings that the heating sequence of the reactants, oil and water, is of fundamental importance to achieve enhanced upgrading performance meaning that byproducts such as solid residue and light hydrocarbon gases are reduced or eliminated. Reducing solid formation not only improves the liquid oil yield but also allows the process to operate more efficiently. It is well understood that solids in the system will pose significant challenges for reactor and process design. Direct heating of oil feed may lead to over heating which in turn leads to more solid residue formation, lower desired product yield and lower product quality.
SUMMARY OF THE INVENTION
[0016] The present invention relates to a process for upgrading hydrocarbons, preferably heavy hydrocarbons comprising: mixing the hydrocarbons with a fluid comprising water that has been heated to a temperature higher than its critical temperature in a mixing zone to form a mixture; passing the mixture to a reaction zone; reacting the mixture in the reaction zone under supercritical water conditions in the absence of externally added hydrogen for a residence time sufficient to allow upgrading reactions to occur; withdrawing a single-phase reaction product from the reaction zone; and separating the reaction product into gas, effluent water, and upgraded hydrocarbon phases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a process flow diagram of an embodiment of the present invention.
[0018] FIG. 2 is a process flow diagram of another embodiment of the present invention.
[0019] FIG. 3 is a graph showing the required T SCW as a function of water-to-oil ratio.
[0020] FIG. 4 is a process flow diagram of another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reactants
[0021] Water and hydrocarbons, preferably heavy hydrocarbons are the two reactants employed in a process according to the present invention.
[0022] Any heavy hydrocarbon can be suitably upgraded by a process according to the present invention. Preferred are heavy hydrocarbons having an API gravity of less than 20°. Among the preferred heavy hydrocarbons are heavy crude oil, heavy hydrocarbons extracted from tar sands, commonly called tar sand bitumen, such as Athabasca tar sand bitumen obtained from Canada, heavy petroleum crude oils such as Venezuelan Orinoco heavy oil belt crudes, Boscan heavy oil, heavy hydrocarbon fractions obtained from crude petroleum oils particularly heavy vacuum gas oils, vacuum residuum as well as petroleum tar, tar sands and coal tar. Other examples of heavy hydrocarbon feedstocks which can be used are oil shale, shale oil, and asphaltenes.
Water
[0023] Any source of water may be used in the fluid comprising water in practicing the present invention. Sources of water include but are not limited to drinking water, treated or untreated wastewater, river water, lake water, seawater produced water or the like.
Mixing
[0024] In accordance with the invention, the heavy hydrocarbon feed and a fluid comprising water that has been heated to a temperature higher than its critical temperature are contacted in a mixing zone prior to entering the reaction zone. In accordance with the invention, mixing may be accomplished in many ways and is preferably accomplished by a technique that does not employ mechanical moving parts. Such means of mixing may include, but are not limited to, use of static mixers, spray nozzles, sonic or ultrasonic agitation. The oil and water should be heated and mixed so that the combined stream will reach supercritical water conditions in the reaction zone.
[0025] It was found that by avoiding excessive heating of the feed oil, the formation of byproduct such as solid residues is reduced significantly. One key aspect of this invention is to design the heating sequence so that the temperature and pressure of the hydrocarbons and water will reach reaction conditions in a controlled manner. This will avoid excessive local heating of oil, which will lead to solid formation and lower quality product. In order to achieve better performance, the oil should only be heated up with sufficient water present and around the hydrocarbon molecules. This requirement can be met by mixing oil with water before heating up.
[0026] FIG. 2 is a process flow diagram of one embodiment of the present invention. In this embodiment, water is heated to a temperature higher than critical conditions, and then mixed with oil. The temperature of heavy oil feed should be kept in the range of about 100° C. to 200° C. to avoid thermal cracking but still high enough to maintain a reasonable pressure drop. The water stream temperature should be high enough to make sure that after mixing with oil, the temperature of the oil-water mixture is still higher than the water supercritical temperature. In this embodiment, the oil is actually heated by water. An abundance of water molecules surrounding the hydrocarbon molecules will significantly suppress condensation reactions and therefore reduce formation of coke and solid product.
[0027] The required temperature of the supercritical water stream, T SCW , can be estimated based on reaction temperature, T R , and water to oil ratio. Since the heat capacity of water changes significantly in the range near its critical conditions for a given reaction temperature the required temperature for the supercritical water stream increases almost exponentially with decreasing water-to-oil ratio. The lower the water-to-oil ratio, the higher the T SCW . The relationship, however, is very nonlinear since higher T SCW leads to a lower heat capacity (far away from the critical point). FIG. 3 shows the required T SCW as a function of water-to-oil ratio when reaction temperature T R =375° C. and pressure=3700 psig. It should be noted that the maximum temperature will be determined based on property of specific feed.
[0028] FIG. 4 shows another embodiment of a process according to the invention. Water is heated up to supercritical conditions by Heater 1 , then the supercritical water mixed with heavy oil feed in the mixer. The temperature of heavy oil feed should be kept in the range of about 100° C. to 200° C. to avoid thermal cracking but still high enough to maintain reasonable pressure drop, After mixing with heavy oil, the temperature of the water-oil mixture would be lower than critical temperature of water; therefore Heater 2 is needed to raise the temperature of the mixture stream to above the critical temperature of water. In this embodiment, the heavy oil is first partially heated up by water, then the water-oil mixture is heated to supercritical conditions by the second heater (Heater 2 ).
[0029] Other methods of mixing and heating sequences based on the above teachings may be used to accomplish these objectives as will be recognized by those skilled in the art.
Reaction Conditions
[0030] After the reactants have been mixed, they are passed into a reaction zone in which they are allowed to react under temperature and pressure conditions of supercritical water, i.e. supercritical water conditions, in the absence of externally added hydrogen, for a residence time sufficient to allow upgrading reactions to occur. The reaction is preferably allowed to occur in the absence of externally added catalysts or promoters, although the use of such catalysts and promoters is permissible in accordance with the present invention.
[0031] “Hydrogen” as used herein in the phrase, “in the absence of externally added hydrogen” means hydrogen gas. This phrase is not intended to exclude all sources of hydrogen that are available as reactants. Other molecules such as saturated hydrocarbons may act as a hydrogen source during the reaction by donating hydrogen to other unsaturated hydrocarbons. In addition, H 2 may be formed in-situ during the reaction through steamy reforming of hydrocarbons and water-gas-shift reaction.
[0032] The reaction zone preferably comprises a reactor, which is equipped with a means for collecting the reaction products (syncrude, water, and gases), and a section, preferably at the bottom, where any metals or solids (the “dreg stream”) may accumulate.
[0033] Supercritical water conditions include a temperature from 374° C. (the critical temperature of water) to 1000° C., preferably from 374° C. to 600° C. and most preferably from 374° C. to 400° C., a pressure from 3,205 (the critical pressure of water) to 10,000 psia, preferably from 3,205 psia to 7,200 psia and most preferably from 3,205 to 4,000 psia, an oil/water volume ratio from 1:0.1 to 1:10, preferably from 1:0.5 to 1:3 and most preferably about 1:1 to 1:2.
[0034] The reactants are allowed to react under these conditions for a sufficient time to allow upgrading reactions to occur. Preferably, the residence time will be selected to allow the upgrading reactions to occur selectively and to the fullest extent without having undesirable side reactions of coking or residue formation. Reactor residence times may be from 1 minute to 6 hours, preferably from 8 minutes to 2 hours and most preferably from 20 to 40 minutes.
Reaction Product Separation
[0035] After the reaction has progressed sufficiently, a single phase reaction product is withdrawn from the reaction zone, cooled, and separated into gas, effluent water, and upgraded hydrocarbon phases. This separation is preferably done by cooling the stream and using one or more two-phase separators, three-phase separators, or other gas-oil-water separation device known in the art. However, any method of separation can be used in accordance with the invention.
[0036] The composition of gaseous product obtained by treatment of the heavy hydrocarbons in accordance with the process of the present invention will depend on feed properties and typically comprises light hydrocarbons, water vapor, acid gas (CO 2 and H 2 S), methane and hydrogen. The effluent water may be used, reused or discarded. It may be recycled to e.g. the feed water tank, the feed water treatment system or to the reaction zone.
[0037] The upgraded hydrocarbon product, which is sometimes referred to as “syncrude” herein may be upgraded further or processed into other hydrocarbon products using methods that are known in the hydrocarbon processing art.
[0038] The process of the present invention may be carried out either as a continuous or semi-continuous process or a batch process or as a continuous process. In the continuous process the entire system operates with a feed stream of oil and a separate feed stream of supercritical water and reaches a steady state whereby all the flow rates, temperatures, pressures, and composition of the inlet, outlet, and recycle streams do not vary appreciably with time.
[0039] While not being bound to any theory of operation, it is believed that a number of upgrading reactions are occurring simultaneously at the supercritical water conditions used in the present process. In a preferred embodiment of the invention the major chemical/upgrading reactions are believed to be:
Thermal Cracking: C x H y →lighter hydrocarbons
Steam Reforming: C x H y +2xH 2 O=xCO 2 +(2x+y/2)H 2
Water-Gas-Shift: CO+H 2 O=CO 2 +H 2
Demetalization: C x H y Ni w +H 2 O/H 2 →NiO/Ni(OH) 2 +lighter hydrocarbons
Desulfurization: C x H y S z +H 2 O/H 2 =H 2 S+lighter hydrocarbons
[0040] The exact pathway may depend on the reactor operating conditions (temperature, pressure, O/W volume ratio), reactor design (mode of contact/mixing, sequence of heating), and the hydrocarbon feedstock.
[0041] The following Examples are illustrative of the present invention, but are not intended to limit the invention in any way beyond what is contained in the claims which follow.
EXAMPLE 1
Showing Typical Laboratory Process
[0042] FIG. 1 shows a process flow diagram for a laboratory unit for practicing some embodiments of the invention. Oil and supercritical water are contacted in a mixer prior to entering the reactor. The reactor is equipped with an inner tube for collecting the products (syncrude, excess water, and gas), and a bottom section where any metals or solids comprising a “dreg stream” of indeterminate properties or composition may accumulate. The shell-side of the reactor is kept isothermal during the reaction with a clamshell furnace and temperature controller. Preferred reactor residence times are 20-40 minutes, with preferred oil/water volume ratios on the order of 1:3. Preferred temperatures are around 374°-400° C. with the pressure at 3,200-4,000 psig. The reactor product stream leaves as a single phase, and is cooled and separated into gas, syncrude, and effluent water. The effluent water is recycled back to the reactor. Sulfur from the original feedstock accumulates in the dreg stream for the most part, with lesser amounts primarily in the form of H 2 S found in the gas phase and water phase.
[0043] As the next examples will show, very little gas is produced in most cases. With suitable choice of operating conditions, it is also possible to reduce or nearly eliminate the “dreg stream.” Elimination of the dreg stream means that a greater degree of hydrocarbon is recovered as syncrude, but it also means that metals and sulfur will accumulate elsewhere, such as in the water and gas streams.
EXAMPLE 2
Properties of the Product Syncrude
[0044] A Hamaca crude oil was diluted with a diluent hydrocarbon at a ratio of 5:1 (20 vol % of diluent). The diluted Hamaca crude oil properties were measured before reacting it with the supercritical water process as referred to in Example 1 and FIG. 2 . The properties of the crude were as follows: 12.8 API gravity at 60/60; 1329 CST viscosity @40° C.; 7.66 wt % C/H ratio; 13.04 wt % MCRT; 3.54 wt % sulfur; 0.56 wt % nitrogen; 3.05 mg KOH/gm acid number; 1.41 wt % water, 371 ppm Vanadium; and 86 ppm Nickel. The diluted Hamaca crude oil after the super critical water treatment was converted into a syncrude with the following properties: 24.1 API gravity at 60/60; 5.75 CST viscosity @40° C.; 7.40 wt % C/H ratio; 2.25 wt % MCRT; 2.83 wt % sulfur; 0.28 wt % nitrogen; 1.54 mg KOH/gm acid number; 0.96 wt % water; 24 ppm Vanadium; and 3 ppm Nickel Substantial reductions in metals and residues were observed, with simultaneous increase in the API gravity and a significant decrease in the viscosity of the original crude oil feedstock. There were modest reductions in the Total Acid number, sulfur concentration, and nitrogen concentration which could be improved with further optimization of the reaction conditions.
[0045] When the diluted Hamaca crude was sent directly to the reactor without being first heated with supercritical water, the product syncrude had the following properties: 14.0 API gravity at 60/60; 188 CST viscosity @40° C.; 8.7 wt % MCRT; 3.11 wt % sulfur, 267 ppm Vanadium; and 59 ppm Nickel. This comparison demonstrates the importance of the heating sequence of the present invention.
[0046] Apart from the occasional, small accumulation of a dreg stream, there is very little coking or solid byproducts formed in the supercritical water reaction. The material balance was performed for two separate experimental runs.
[0047] In the experimental run with no dreg stream formed, the starting feedstock of diluted Hamaca crude at 60 grams produced a syncrude product of 59.25 grams which corresponds to a high overall recovery of 99 percent. It was thought that due to the absence of a dreg stream, the experimental mass balance was impacted in the determination of the sulfur and metals. The gas phase did not contain metals species and had little sulfur compounds. It was hypothesized that a portion of the metal and sulfur may have accumulated on the walls of the reactor or downstream plumbing. In the experimental run with a dreg stream formed, the starting feedstock of diluted Harmaca crude at 30 grams produced a syncrude product of 22.73 grams. The dreg stream that was formed accounted for 5.6 grams. The overall recovery with the dreg stream was 96.7 percent. In the dreg stream, sulfur accounted for 31% of the total sulfur with the remaining sulfur in the oil product, water phase, and gas phase. The metals content of the dreg stream accounted for 82% of, the total metals with the remaining metals in the oil product. For commercial operations, it may be preferable to minimize the formation of a dreg stream, since it represents a 18% reduction in syncrude product, and generates a lower value product stream that impacts the process in terms of economics and disposal concerns.
[0048] Undiluted Boscan crude oil properties were measured before reacting it with the supercritical water process of the present invention. The properties of the crude were as follows, 9 API gravity at 60/60; 1,140 CST viscosity @40° C.; 8.0 wt % C/H ratio; 16 wt % MCRT; 5.8 wt % Sulfur; and 1,280 ppm Vanadium; The undiluted Boscan crude oil after the super critical water treatment was converted into a syncrude with the following properties: 22 API gravity at 60/60; 9 CST viscosity @40° C.; 7.6 wt % C/H ratio; 2.5 wt % MCRT; 4.6% sulfur; and 130 ppm Vanadium.
[0049] A simulated distillation analysis of the original crude oil vs. the syncrude products from different experimental runs shows that the syncrude prepared in accordance with the present invention clearly has superior properties than the original crude. Specifically, the syncrudes contain a higher fraction of lower-boiling fractions. 51% of the diluted Hamaca crude boils across a range of temperatures of less than 1000° F., while employing a process according to the present invention using supercritical water depending on process configurations, between 79 to 94% of the syncrude boils across a range of temperatures of less than 1000° F. 40% of the undiluted Boscan crude boils across a range of temperatures of less than 1000° F., while employing a process according to the present invention using supercritical water, 93% of the syncrude boils across a range of temperatures of less than 1000° F.
[0050] There are numerous variations on the present, invention which are possible in light of the teachings and supporting examples described herein. It is therefore understood that within the scope of the following claims, the invention may be practiced otherwise than as specifically described or exemplified herein. | A process using supercritical water to upgrade a heavy hydrocarbon feedstock into an upgraded hydrocarbon product or syncrude with highly desirable properties (low sulfur content, low metals content, lower density (higher API), lower viscosity lower, residuum content, etc.) is disclosed. The process does not require external supply of hydrogen nor does it use externally supplied catalysts. Improved methods of mixing the reactants are also disclosed. | 2 |
This application claims priority from U.S. Provisional application Ser. No 61/133,144, filed Jun. 26, 2008.
The invention claimed and disclosed herein deals with devices that are useful for constructing fences using only one person.
Thus, which is disclosed is a device that allows for the construction of a fence by an individual, as opposed to two or more persons by lifting fence segments and aligning such fence segments with each other and making the fence level.
Fence construction is commonly carried out by two or more persons because generally, one person has to lift hold the fence segment in place while the other person or persons level the fence segment and align it with other fence segments to create a straight line of fencing.
The combination as set forth herein allows for only one person to construct such a fence.
BACKGROUND OF THE INVENTION
The inventor herein is unaware of any other devices analogous to the device disclosed herein.
THE INVENTION
What is disclosed and claimed herein is a fence lifter and leveler comprising in combination a clamping assembly for attachment to a fence post; a hollow leg, the leg being separately detachedly affixed to the clamping assembly.
The clamping assembly is comprised of a two component housing wherein a first component is comprised of a flat plate configured in an L-shape wherein the L-shaped flat plate has a back wall with a top edge, and the top edge has a center point and a bottom edge. There is a side wall wherein the side wall has a top edge, a bottom edge, and a front edge and wherein, there is a threaded opening through the side wall located in an upper corner near the top edge and the front edge to accommodate a threaded, knurled knob. There is a non-threaded opening in a bottom corner near the bottom edge and the front edge.
The back wall has a linear series of bolt openings through it which are located near the top edge, and a second set of a linear series of bolt openings through it which are located near the bottom edge wherein at least one bolt opening in each series has a bolt fastened through it.
There is a second and a third non-threaded opening, each located at the end of one of the series of bolt openings.
The first component has located at the top edge, at the center point of the back wall, a stabilizer tab.
There is a second component comprised of a flat plate configured in an L-shape, the L-shaped flat plate has a side wall and a back wall wherein the back wall is alignable with, and mateable to, the back wall of the first component. The side wall has a top edge, a front edge and a back corner, wherein there is a threaded opening through the side wall located in an upper corner near the top edge and the front edge to accommodate a threaded, knurled knob, there being a non-threaded opening near the bottom edge and the front edge. There is a second threaded opening equidistant between the bottom edge and the top edge and near the back wall to accommodate a threaded knurled knob having a distal end, the distal end having affixed thereto a flat plate.
The leg comprises three components comprising an elongated tubular top segment, an elongated tubular bottom segment and, a threaded rod, the threaded rod having a top end and a bottom end. The threaded rod has a means fixed at the top end for driving the threaded rod.
The bottom segment has a top end and a bottom end wherein there is a lateral foot fixedly attached to the bottom end and a threaded opening fixed in the top end.
The top segment has a bottom end and a top end wherein the bottom end is open such that the top end of the bottom segment is insertable and moveable in the bottom segment, bottom end opening, and there is a non-threaded opening in the top end for insertion of the threaded rod.
The top segment has attached to the top thereof a clamping assembly adapter, said clamping assembly adapter comprising a hollow tubular member having a back wall and two side walls each side wall having an outer surface, the clamping assembly adapter being fixed to the top of the elongated tubular top segment, each of the hollow tubular members side walls having an upper end and a lower end, each upper end of each of the side walls having a slot therein, each lower end of the side walls having a guide post and stabilizer pin attached to the outer surface thereof.
There are at least two threaded knurled knobs and at least one threaded, knurled knob having a distal end wherein the distal end has affixed thereto, a flat plate.
When the elongate tubular top segment and the elongate tubular bottom segment are joined, the clamping assembly adapter and the lateral foot are aligned vertically with each other and, and the elongated threaded rod is inserted in the opening in the top end of the elongated tubular top segment. The threaded rod bottom end is threaded into the threaded opening in the top end of the bottom segment.
Another embodiment of this invention is a fence lifter and leveler as set forth just above in combination with an apparatus to hold the fence on the feet of the legs.
Yet another embodiment of this invention is a kit, said kit comprising the combination of the fence leveler and the apparatus to hold the fence on the feet of the legs of the fence lifter and leveler, and a means for mechanically rotating the elongated rods such as a wrench.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a full front view of a fence lifter and leveler of this invention.
FIG. 2A is a full back view of the housing of the fence lifter showing it with the leg removed.
FIG. 2B is a side view of the component 4 of FIG. 2A .
FIG. 2C is a full top view of the housing 9 of this invention.
FIG. 3A is a full side view of the top segment of a leg showing the clamping assembly adapter affixed to the top of the top segment.
FIG. 3B is a full top view of the top segment of the leg of FIG. 3A showing the non-threaded opening.
FIG. 4A is a full side view of the lower segment of a leg.
FIG. 4B is a full top view of the lower segment of a leg showing the threaded opening.
FIG. 5 is a full view of an elongated rod.
FIG. 6 is a full side view of the clamp housing without any other parts associated with it.
FIG. 7 is a full view of the clamping key.
FIG. 8 is a full view of the attachment device for attaching the legs to the housing.
FIG. 9 is a full side view of the holding apparatus of this invention showing the bolt for attaching the two components.
FIG. 10 is a full side view of the device of FIG. 9 showing the adjustment bolt openings.
FIG. 11 is a full top view of the holding assembly of this invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a full front view of a device 1 of this invention showing the housing 9 , the leg 2 , the upper part of the leg 3 , the stabilizing tab 4 on the back wall 5 , the foot 17 and the lower part 6 of the leg 2 .
Also shown is the clamping key 8 , and the attachment key 7 for attaching the leg 2 to the housing 9 .
Also shown is the elongated rod 10 with the means 11 for rotating the elongated rod 10 .
Turning now to FIG. 2A , in which there is shown a full back view of the housing 9 of this invention showing the stabilizing tab 4 on the back wall 5 , front wall 5 ′, the clamping key 8 and the attachment key 7 . Also shown are the side walls 13 .
Shown in the middle of the back 5 ′ are openings 39 , which are non-threaded and which accommodate fasteners therethrough. In FIG. 1 there is shown threaded openings 40 which are alignable with the openings 39 . These openings 39 and 40 are used to create the adjustability of the two components forming the housing 9 . The threaded fasteners are inserted through openings 39 and threaded into openings 40 to hold the two components together.
FIG. 3A is a full side view of the top segment 3 of a leg 2 showing the clamping assembly adapter 26 affixed to the top 27 of the upper segment 3 of the leg 2 . Fixedly attached to the side wall of the clamping assembly adapter 26 is a post 28 which is introduced into a hole 29 ( FIG. 6 ) in the side wall 13 of the housing 9 . This post 28 is used to help stabilize the clamping assembly adapter 26 against the housing 9 . Also shown is the elongated threaded rod 10 with its means 11 for rotating the threaded elongated rod 10 .
FIG. 3B shows a full top view of the upper leg segment 3 showing the opening 18 through which the threaded elongated rod 10 is inserted into the upper leg segment 3 .
FIG. 4A shows the bottom portion 6 of the leg segment 3 and FIG. 4B shows a full top view of the bottom portion 6 showing the threaded opening 21 that the elongated rod 10 is threaded into.
FIG. 5 is a full view of a threaded elongated rod 10 of this invention showing the rotation means 11 .
FIG. 6 is a full side view of a housing 9 of this invention and FIGS. 7 and 8 show the clamping key 8 comprised of a handle 22 and a threaded shaft 23 , and a flat plate 33 , for clamping the device to a fence post. The clamping key 8 is threaded through the threaded opening 36 in the side wall 13 ( FIG. 6 ) of the housing 9 during manufacture. The flat plate 33 is then attached (during manufacturing).
In use, the clamping key 8 is turned in the threaded opening 36 until the flat plate 33 encounters the fence post and thereafter, the clamping key 8 is tightened against the fence post.
The attachment key 7 , comprised of a handle 31 and a threaded shaft 32 for attaching legs 2 to the housing 9 . Such attachment is achieved by laying the leg 2 against the housing 9 such that the post 28 fits into the opening 29 in the housing wall 13 . The attachment key 7 is then inserted into the threaded opening 34 ( FIG. 6 ), and the slot 35 in the clamping assembly apparatus 26 , and the attachment key 7 is then tightened to support the leg 2 against the outside surface of the side wall 13 of the housing 9 .
FIG. 9 is a full front view of the holding apparatus 25 of this invention and FIG. 10 is a full side view of the holding apparatus 25 which consists of a common back bar 37 that has a distal end 19 and a near end 20 . The distal end 19 is bent into a U-shape 15 in order to allow that portion to fit over the top edge of a fence that is being erected. The near end of the common back bar 37 is fixedly attached to the housing 12 .
The housing 12 of the holding apparatus 25 is comprised of two components that are comprised of two flat plates that are bent in an L-shape as is the housing 9 to form two side walls 16 that are unitarily connected to the backs 14 and 14 ′ (see FIG. 11 ).
FIG. 11 is a full top view of the holder assembly 25 showing the overlapping of the backs 14 and 14 ′ along with a bolt 24 as the fastener for the two components.
Back 14 has one opening (not shown) where bolt 24 is located as shown in FIGS. 9 and 11 . The other back 14 ′ has a series of bolt openings, designated a A, B, and C in FIG. 10 which allows for the adjustment of the housing 25 to accommodate various sized fence posts. Also shown in FIGS. 9 and 10 is the projection 38 , which presses against the fence to keep the holder 25 and the fence thereupon, to remain essentially vertical.
In use, the lifter device 1 is positioned on a fence post and attached thereto. Thereafter, a section of fence is placed on the lateral foot 17 of the device 1 , on the elongated bottom segment 6 and lifted into place against the fence post. Thereafter, a holding apparatus 25 is dropped over the fence post and the top part 15 is dropped over the top edge of the fence to temporarily hold the fence against the post. In this manner, the fence is held against the post and is then lifted by the fence lifter and leveler 1 to the desired height and position and in level alignment with previously placed fence segments. Thereafter, the fence segment is fixedly attached to the fence post and the fence lifter and leveler 1 is removed along with the holding apparatus 25 .
What is shown in FIG. 1 is one configuration of the fence lifter of this invention. It should be noted by those skilled in the art that the leg 2 can be used on the opposite side of the housing 9 to create and left hand version and a right hand version of the device. This capability allows for the building of fences having any configuration. | Devices that are useful for constructing fences. Such devices are comprised of a combination of a fence lifter and leveler and a holding apparatus so that only one person can construct the fence. | 4 |
[0001] The invention relates generally to the field of welding and more particularly directed to electrodes having improved weld bead formation properties, and even more particularly directed to electrodes that form weld beads with enhanced slag placement and removal properties.
BACKGROUND OF THE INVENTION
[0002] In the field of arc welding, the main types of welding processes are gas-metal arc welding with solid (GMAW) or metal-cored wires (GMAW-C), gas shielded flux-cored arc welding (FCAW-G), self shielded flux-cored arc welding (FCAW-S), shielded metal arc welding (SMAW) and submerged arc welding (SAW). Of these processes, gas metal arc welding with solid or metal-cored electrodes are increasingly being used for joining or overlaying metallic components. These types of welding processes are becoming increasingly popular because such processes provide increased productivity and versatility. Such increase in productivity and versatility results from the continuous nature of the welding electrodes in gas metal arc welding (GMAW & GMAW-C), which offers substantial productivity gains over shielded metal arc welding (SMAW). Moreover, these electrodes produce very good looking welds with very little slag, thus saving time and expense associated with cleaning welds and disposing of slag, a problem that is often encountered in the other welding processes.
[0003] In gas metal arc welding with solid or metal cored electrodes, a shielding gas is used to provide protection for the weld against atmospheric contamination during welding. Solid electrodes are appropriately alloyed with ingredients that, in combination with the shielding gas, provide porosity free welds with the desired appearance and mechanical properties. In metal cored electrodes, these ingredients are on the inside, in the core (fill) of a metallic outer sheath, and provide a similar function as in the case of solid electrodes.
[0004] Solid and metal-cored electrodes are designed to provide, under appropriate gas shielding, a solid, substantially porosity free weld with yield strength, tensile strength, ductility and impact strength to perform satisfactorily in the final applications. These electrodes are also designed to minimize the quantity of slag generated during welding; however, small slag islands and/or one or more thin lines of slag at the toes of the weld are often formed during welding. In general, these slag islands are oxides of manganese and silicon that are formed, when these elements that are present in the wire react with oxygen during welding. After welding, these slag islands or slag lines are removed to provide a clean surface that, if desired, can be later treated (e.g. painted or coated) to enhance appearance, inhibit corrosion, etc. Failure to remove the slag can result in peeling of the slag after the weld has been painted or coated, which can result in corrosion at that site or negatively impact the cosmetic appearance of the weld.
[0005] Metal-cored electrodes are used increasingly as an alternative to solid wires because of increased productivity during welding fabrication of structural components. Metal cored electrodes are composite electrodes consisting of a core (fill) material surrounded by a metallic outer sheath. The core consists mainly of iron powder and alloying and fluxing ingredients to help with arc stability, weld wetting and appearance etc., such that the desired appearance and mechanical properties are obtained in the weld. Metal cored electrodes are manufactured by mixing up the ingredients of the core material and depositing them inside a formed strip, and then closing and drawing the strip to the final diameter. Metal-cored electrodes provide increased deposition rates and produce a wider, more consistent weld penetration profile compared to solid electrodes. Moreover, they provide improved arc action, generate less fume and spatter, and provide weld deposits with better wetting compared to solid electrodes. However, these productivity improvements are sometimes offset by the expense incurred because of the time required to remove the slag deposits or islands, which form on the surface of the weld.
[0006] In general, in gas metal arc welding with solid or metal cored wires, the slag islands tend to form at the toes of the weld. The slag islands get wedged in the toes and this makes them very difficult to remove. In this invention, addition of ingredients to the core (fill) of the metal core electrode have been made, which allow for the slag to form as discrete islands in the middle of the weld, instead of the toes of the weld. This allows the slag islands to either self detach or be removed easily.
[0007] Several fill compositions have been developed to address the slag removal problem. In U.S. Pat. No. 4,345,140 to Godai, a flux composition use in a cored electrode for welding stainless steel is disclosed. Godai discloses that the addition of low melting point metallic oxides such as lead oxide, copper oxide, bismuth oxide, antimony oxide or tin oxide is useful in enhancing the separability of slag. The teachings of Godai are incorporated herein by reference.
[0008] Another fill composition having improved slag removal is disclosed in U.S. Pat. No. 6,608,284 to Nikodym. Nikodym discloses a fill composition for a mild steel or low alloy steel electrode. Nikodym distinguishes the disclosed fill composition from the fill composition disclosed in Godai on the basis that Godai is directed to a flux cored electrode for stainless steel welding which is fundamentally different from metal-cored electrodes for mild steel and low alloy steel welding. Nikodym asserts that flux cored electrodes for use in the welding of stainless steel include a flux composition consisting of nonmetallic inorganic components that are present in significantly higher percentages (e.g., 5 to 10%) than in metal cored electrodes for use in the welding of mild or low alloy metals, thus resulting in the slag covering the entire surface of and adhering strongly to the weld bead thereby making it very difficult to remove. The fill composition disclosed in Nikodym includes the addition of antimony, bismuth and/or germanium to a weld metal to cause slag deposits or islands on the weld metal to form at positions away from the toe or edge of mild and low alloy steel weld beads, thereby facilitating the removal of the slag deposits or islands. The teachings of Nikodym are incorporated herein by reference.
SUMMARY OF THE INVENTION
[0009] The present invention pertains to an improved welding electrode that facilitates in causing slag deposits or islands on the weld metal to form at positions away from the toe or edge of mild and low alloy steel weld beads, thereby facilitating the removal of the slag deposits or islands. The welding electrode of the present invention is particularly directed to an electrode that includes a fill composition which at least partially protects a weld metal from oxygen and nitrogen throughout the welding process. As such, the fill composition of the present invention is particularly directed to cored electrodes having a metal sheath that surrounds the fill composition in the core of the sheath; however, the fill composition can be applied to other types of electrodes (e.g., coating on a stick electrodes, etc.), or be used as or part of a flux composition in a submerged arc welding process. As a result, the fill composition is not limited for use in a cored electrode The fill composition of the present invention is particularly formulated for use with electrodes used to weld mild and low alloy steel; however, the fill composition can be used with electrodes for the formation of welding beads on other types of metals. The metal electrode (e.g., metal sheath, solid rod, etc.) is typically formed primarily from iron (e.g., carbon steel, low carbon steel, stainless steel, low alloy steel, etc.); however, the base metal can be primarily formed of other materials (e.g., copper, nickel, titanium, etc.). When the fill composition is used in a cored electrode, the fill composition typically constitutes at least about 1 weight percent of the total electrode weight, and not more than about 50 weight percent of the total electrode weight, and typically about 10-35 weight percent of the total electrode weight, and more typically about 15-25 weight percent of the total electrode weight, and even more typically about 18-22 weight percent of the total electrode weight. The fill composition includes one or more slag forming agents that are used to facilitate the formation of the weld bead, and/or to at least partially shield the formed weld bead from the atmosphere. The fill composition can also include one or more metal alloying agents selected to at least closely match the desired weld metal composition, and/or to obtain the desired properties of the formed weld bead. In one embodiment of the present invention, the fill composition includes indium and/or one or more indium compounds to improve the slag properties of the flux system during and/or after the formation of a weld bead during a welding operation. It has been found that the addition of indium and/or one or more indium compounds to a welding electrode results in the slag deposits or islands formed on the weld bead to form at positions removed from the toe or edge of the weld bead, thereby facilitating the removal of the slag from the weld bead. It has not been determined whether the improved slag properties are the result of the effect of indium and/or one or more indium compounds on the properties of the slag as the slag forms on the weld bead and/or the incorporation of indium and/or one or more indium compounds into the weld metal and the effects of the weld metal properties on the slag formed on the weld metal. The inclusion of indium and/or one or more indium compounds in the welding electrode significantly improves the ease of slag removal. The indium and/or one or more indium compounds is generally incorporated in the fill composition that can be incorporated in the core of a cored electrode, and/or be incorporated in the composition of the metal rod or metal sheath of the welding electrode. Various indium and/or an indium compounds that can be included in the fill composition include, but are not limited to, indium, indium antimonide, indium oxide, indium fluoride, indium sulfate, indium sulfide, or mixtures thereof In one aspect of this embodiment, the indium and/or an indium compound content of the fill composition is generally at least about 0.02 weight percent of the fill composition, typically about 0.05-15 weight percent of the fill composition, more typically about 0.1-8 weight percent of the fill composition, and even more typically about 0.5-2 weight percent of the fill composition. In another and/or alternative aspect of this embodiment, the indium and/or an indium compound content of the welding electrode is generally at least about 0.004 weight percent of the total electrode, and typically about 0.0095-3.23 weight percent of the total electrode, more typically about 0.019-1.72 weight percent of the total electrode, and even more typically about 0.095-0.43 weight percent of the total electrode.
[0010] In another and/or alternative aspect of the present invention, the composition of the metal rod or metal sheath of the welding electrode is selected to at least closely match the desired weld metal composition. Typically the metal rod or metal sheath includes a majority of iron when welding a ferrous based workpiece (e.g., carbon steel, stainless steel, etc.); however, the composition of the weld rod can include various types of metals to achieve a particular weld bead composition. In one embodiment of the invention, the metal rod or metal sheath primarily includes iron and one or more other elements such as, but not limited to, aluminum, antimony, bismuth, boron, carbon, cobalt, copper, lead, manganese, molybdenum, nickel, niobium, silicon, sulfur, tin, titanium, tungsten, vanadium, zinc and/or zirconium. In another and/or alternative embodiment of the invention, the metal rod or metal sheath primarily includes iron and one or more other elements such as, but not limited to, aluminum, carbon, chromium, nickel silicon, and/or titanium. In still another and/or alternative embodiment of the invention, the iron content of the metal rod or metal sheath is at least about 80 weight percent of the metal rod or metal sheath.
[0011] In still another and/or alternative aspect of the present invention, the fill composition includes one or more weld metal protection agents and/or modifying agents. The components of the fill can include metal alloying agents (e.g., aluminum, boron, calcium, carbon, chromium, iron, manganese, nickel, silicon, titanium, zirconium, etc.) that are at least partially used to provide protection to the weld metal during and/or after a welding procedure, to facilitate in a particular welding procedure, and/or to modify the composition of the weld bead. In one embodiment of the invention, the fill composition includes at least one of the weld metal protection agents. In another and/or alternative embodiment of the invention, the fill composition includes one or more alloying agents used to facilitate in forming a weld metal with the desired composition. In one aspect of this embodiment, the alloying agent constitutes about 0.1-99.3 weight percent of the fill composition. In still another and/or alternative embodiment of the invention, the fill composition includes one or more slag modifiers. The slag modifiers are typically used to increase and/or decrease the viscosity of the slag, to improve the ease of slag removal from the weld metal, reduce spattering, etc.
[0012] In still yet another and/or alternative aspect of the present invention, a shielding gas is used in conjunction with the welding electrode to provide protection to the weld bead from elements and/or compounds in the atmosphere. The shielding gas generally includes one or more gases. These one or more gases are generally inert or substantially inert with respect to the composition of the weld bead. In one embodiment, argon, carbon dioxide or mixtures thereof are at least partially used as a shielding gas. In one aspect of this embodiment, the shielding gas includes about 2-40 percent by volume carbon dioxide and the balance of argon. In another and/or alternative aspect of this embodiment, the shielding gas includes about 5-25 percent by volume carbon dioxide and the balance of argon. As can be appreciated, other and/or additional inert or substantially inert gases can be used.
[0013] It is a primary object of the invention to provide a welding process that results in improved slag properties on the weld bead.
[0014] Another and/or alternative object of the present invention is the provision of a welding process that reduces the amount of slag formed and the amount of slag that is in and/or near the toes of the weld bead.
[0015] Still another and/or alternative object of the present invention is the provision of a welding electrode that includes indium and/or one or more indium compounds to improve the characteristics of slag formed on a weld bead.
[0016] Yet another and/or alternative object of the present invention is the provision of a metal cored welding electrode that includes indium and/or one or more indium compounds in the fill of the electrode to improve the characteristics of slag formed on a weld bead.
[0017] These and other objects and advantages will become apparent from the discussion of the distinction between the invention and the prior art and when considering the preferred embodiment as shown in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1A-1D are illustrations of weld beads form by a cored electrode in accordance with the present invention at various wire feed speeds.
DETAILED DESCRIPTION OF THE INVENTION
[0019] Referring now in greater detail to the drawings, wherein the showings are for the purpose of illustrating preferred embodiments of the invention only, and not for the purpose of limiting the invention, FIGS. 1A-1D illustrate the slag formation on a fillet weld bead formed from a cored electrode in accordance with the present invention. The cored electrode was formulated to weld mild steel; however, it can be appreciated that the welding electrode could have been formulated to weld other types of metal (e.g., stainless steel, high strength steel, etc.). The weld beads illustrates in FIGS. 1A-1D were formed by a robot welder at about 13/16 inch CTWD (contact tip to work distance), about a 10° push angle and about a 45° gun angle. The shielding gas mixture used during the welding process was about 90% AR and about 10% CO 2 . The weld settings that were used on mill scale plates were 1) 24 V/250 ipm WFS (wire feed speed) at about 12 ipm travel speed, 2) 26 V/350 ipm WFS at about 16 imp travel speed, 3) 28 V/450 ipm WFS at about 20 ipm travel speed.
[0020] FIGS. 1A and 1B illustrate fillet welds made on clean plates at two different wire feed speeds. As illustrated in these figures, most of the slag formed by the electrodes is spaced away from the edge of the weld bead and is deposited in discrete slag formations as opposed to being spread out along the length of the weld bead at the toes. FIGS. 1C and 1D illustrate fillet welds made on mill scale plates by the electrodes of the present invention at two different wire feed speeds. Once again, most of the slag formed by the present invention is spaced away from the edge of the weld bead, and is substantially deposited in discrete slag formations as opposed to being spread out along the length of the weld at the toes. In addition, the bead wetting and appearance on both clean plate and mill scale plate is excellent.
[0021] The metal sheath that can be used to form the weld bead can include about 0-0.2 weight percent B, about 0-0.2 weight percent C, about 0-12 weight percent Cr, about 0-5 weight percent Mn, about 0-2 weight percent Mo, about 0-5 weight percent Ni, about 0-4 weight percent Si, about 0-0.4 weight percent Ti, about 0-0.4 weight percent V and about 75-99.9 weight percent Fe. The general formulation of the metal sheath used to form the weld beads in FIG. 2 includes about 0.02-0.044% carbon, about 0.007-0.014% silicon, about 0.02-0.06% aluminum, about 0.01-0.05% chromium, about 0.01-0.04% nickel, less than about 0.014% phosphorus, less than about 0.02% sulfur, less than about 0.01% nitrogen and less than about 0.01% titanium and the balance iron and nominal impurities.
[0022] Metallic indium may also be included in the metal sheath; however, indium and/or one or more indium compounds are typically included in the fill of the cored electrode. These elemental compositional ranges can be solely included in the metal sheath or be a combination of the metal sheath composition and one or more components of the fill composition. The composition of most welding electrodes used for welding mild steel or low alloy steel will include at least about 0.4 weight percent Mn, at least about 0.2 weight percent Si, and at least about 0.001 weight percent C. Industry standards for many mild and low alloy steels limit the combined amounts of B, Cr, Ni, Mo, V, and Ti to less than about 1 weight percent; however, other percentages are acceptable for other types of steel. These elements can be included in the metal sheath, in the fill composition or both to achieve the desired compositional levels.
[0023] The fill composition used in a cored electrode constituted about 19-21.5 weight percent of the total electrode weight. The indium addition to the electrode can typically be in the form of metallic indium when added to the metal sheath and was typically indium oxide included in the fill composition; however, the indium can be added in other and/or additional forms such as, but not limited to, indium antimonide, indium fluoride, indium sulfate and/or indium sulfide. The fill composition used to form the weld beads in FIG. 2 included about 6-13% manganese powder, about 3.5-8.5% Si, about 0.06-0.2% iron sulfide, about 0.4-2% indium oxide and about 70-80% iron powder.
[0024] The addition of indium and/or one or more indium compounds had no noticeably adverse affect on the quality of the electric arc during the welding process. The addition of indium and/or one or more indium compounds had no noticeably adverse affect on the quality or properties of the formed weld bead. The AWS plate welded with the electrode of the present invention yielded a weld bead having a yield strength of about 63 ksi, a tensile strength of about 79 ksi, and elongation of about 29% and a charpy toughness of 29 ft-lbs @ −20° F. As a result, there was no need to add or increase the amount of alloying agents in the electrode to compensate for the effects of indium and/or one or more indium compounds in the weld electrode.
[0025] As illustrated in FIG. 2 , the addition of the indium oxide in the fill composition of the welding electrode resulted in the slag formed during the welding procedure to substantially stay in the weld crater, thereby significantly reducing the amount of slag that moved and/or formed on the edges of the weld bead during the welding procedure. It is believed that the indium oxide positively affects the freezing point as well as the surface tension of the formed slag thereby enabling the formed slag to stay in the weld crater.
[0026] These and other modifications of the discussed embodiments, as well as other embodiments of the invention, will be obvious and suggested to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the present invention and not as a limitation thereof. | A metal core electrode used to form weld deposits having improved slag forming properties with respect to reduced accumulation of slag in toes of the weld bead. The metal cored electrode includes a metal rod and a fill composition. The electrode includes a slag-modifying additive that contains metallic indium and/or one or more indium compounds. | 1 |
STATEMENT AS TO RIGHTS OF INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
This invention was made with Government support under Contract Number DAAK 20-84-C-0147 awarded by the Department of Defense (DOD). The government has certain rights in this invention.
CROSS REFERENCE TO RELATED APPLICATIONS
This is a division of application Ser. No. 917,982, filed on Oct. 10, 1986, now U.S. Pat. No. 4,746,475.
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to polymer films. More particularly, this invention relates to ultrathin, cellulose ester polymer films and their production.
2. Prior Art
The preparation of films from cellulosic polymers on a liquid support, such as water, is known. For example, in U.S. Pat. No. 2,760,233, a process for preparing curved cellulose ester sheets is disclosed. However, no specific solvent mixtures and ratios suitable for casting ultrathin, pinhole-free, cellulose ester films are disclosed not are any film thickness given.
U.S. Pat. No. 3,445,321 discloses a process for producing hole-free, permselective films with thickness between 0.25 and 10 mils. Films are cast on a liquid surface, such as mercury. Suitable polymeric materials from which films can be prepared include cellulosic esters. However, the films of this patent are not ultrathin.
In U.S. Pat. No. 3,933,561, a process for preparing polymeric films on water is disclosed. The film thicknesses are usually less than about 2.5 microns (i.e., 25,000 angstroms) and thickness of 0.1 micron (i.e., 1,000 angstroms) are reportedly achieved. Polysaccharides, including cellulosic polymers, are reportedly suitable for the patent's process. However, specific solvent mixtures and ratios suitable for casting ultrathin, pinhole-free, cellulose ester films having thicknesses of 400 angstroms or less are not disclosed.
U.S. Pat. No. 3,551,244 discloses a process for preparing on a water surface films having thicknesses between 0.05 and 5.0 microns (i.e. between 500 and 50,000 angstroms). The patent lists polyssacharide derivatives, such as cellulose acetate, as suitable polymers. However, specific solvent mixtures and ratios suitable for casting ultrathin, pinhole-free, cellulose ester films having thickness of 400 angstroms or less are not disclosed.
U.S. Pat. Nos. 4,155,793, 4,272,855 and 4,374,891 disclose processes for preparing substantially void-free, ultrathin, permeable polymeric membranes having thicknesses of 500 angstroms or less. The patents assert that organic and inorganic polymers are suitable for use therein. However, only films prepared from organopolysiloxane-polycarbonate interpolymers mixed with polyphenylene oxide are disclosed in the examples. Cellulose ester films are not disclosed nor are suitable solvent mixtures and ratios for casting ultrathin, pinhole-free, cellulose ester films disclosed.
U.S. Pat. No. 2,689,187 discloses ultrathin nitrocellulose films. However, it does not disclose any organic cellulose ester films or suitable solvent ratios and mixtures for casting pinhole-free, ultrathin, cellulose ester films.
Other patents, such as U.S. Pat. Nos. 2,631,334, and 4,393,113, also disclose ultrathin polymeric films. However, no cellulose ester films are disclosed.
In the prior art, the preparation of ultrathin, pinhole-free, cellulose ester, free-standing films with thicknesses of less than 400 angstroms generally has not been disclosed. Usually, such polymer films with thicknesses of less than 400 angstroms that are cast contain holes or other macroscopic defects.
Therefore, it is an object of this invention to prepare ultrathin, cellulose ester polymer films.
It is a further object of this invention to prepare pinhole-free, cellulose ester polymeric films.
It is also an object of this invention to prepare free-standing, cellulose ester films having thicknesses of 400 angstroms or less.
These and other objects are obtained by the products and process of the present invention.
SUMMARY OF INVENTION
The present invention is pinhole-free, ultrathin, cellulose ester films having thicknesses of about 400 angstroms or less. The films are prepared by dissolving a cellulose ester polymer in a suitable mixture of 1,2,3-trichloropropane, methylene chloride and methanol to form a polymeric solution, casting the solution on water to form a free-standing film and removing the film from the water. The ultrathin films of the present invention can be used in separatory applications and as drug release membranes to facilitate the controlled release of drugs.
DETAILED DESCRIPTION OF INVENTION
The preparation of cellulose esters such as cellulose acetate, cellulose triacetate, cellulose propionate, cellulose butyrate, cellulose acetate butyrate, and cellulose acetate propionate, is well known. Cellulose esters can be prepared in a variety of ways, such as esterification of cellulose with acids, anhydrides of acid chlorides. The preferred process is the esterification of cellulose with anhydrides in the presence of a mineral acid catalyst, such as sulfuric acid.
Suitable processes for making cellulose esters are disclosed in "Cellulose Esters, Organic," in Encyclopedia of Polymer Science and Technology, volume 3, Interscience Publishers, a division of John Wiley and Sons, Inc., New York, 1965, pp. 332-344, and U.S. Pat. Nos. 2,026,583, 2,582,049, 2,539,586, 2,740,776, 2,259,462, 2,824,098, 2,339,631, and 2,607,771 which are incorporated herein by reference.
A typical process for the preparation of cellulose esters involves mixing cellulose and an appropriate acyl acid in a container until the cellulose has become swollen with the acid. For example, if cellulose acetate is the desired product, acetic acid is the appropriate acid. When the acid is absorbed in the cellulose, it permits the sulfuric acid catalyst to be uniformly and rapidly absorbed throughout the cellulose.
After the cellulose has become swollen, a small portion of the sulfuric acid catalyst is added to begin the break down of the cellulose before esterification is started. The mixture is cooled and then a cooled excess of the anhydride corresponding to the acyl acid is added. For example, if cellulose butyrate is the desired product, butyric acid is added as described above, and the corresponding anhydride is butyric anhydride.
Since higher acyl anhydrides react more slowly with the hydroxyl groups of the cellulose, it is preferred to speed up the esterification reaction by employing a higher concentration of anhydride and lowering the amount of acid present than when lower acyl acids, such as acetic acid, are employed. After the anhydride is added, the mixture is then cooled and the remainder of the sulfuric acid is added. Since acetylation is an exothermic reaction, it is usually necessary to regulate the reaction temperature. For example, when cellulose acetate or triacetate is prepared, the temperature should be regulated so that it increases to between 90° and 95° F. during an interval of 1.5 to 2 hours. One means of controlling the temperature is by adding a precooled anhydride.
As the esterification nears completion, the reaction solution becomes clear and the reaction temperature is relatively constant until the desired viscosity is obtained. At this point, the triester of cellulose has been formed.
To halt the esterification reaction and to begin hydrolysis, water in the form of aqueous acid is added to destroy the excess anhydride. For example 60-75 percent acetic acid in water is added when cellulose acetate is prepared. When the desired acetyl content is reached, a suitable amount of magnesium oxide or magnesium carbonate is added to neutralize the sulfuric acid catalyst. The cellulose ester is then precipitated, washed free of acid, and dried.
If the cellulose triester is desired, a suitable amount of magnesium oxide or magnesium carbonate is added along with the water to neutralize the sulfuric acid. The resulting solution is held at an elevated temperature until substantially all the sulfuric acid is neutralized.
It is also possible to prepare mixed esters, such as cellulose acetate butyrate and cellulose acetate propionate. They are prepared by the same general process as that used for cellulose acetate except that the higher acyl anhydrides or higher acyl acids are added with acetic anhydride or with glacial acetic acid in the esterification mixture to produce a uniform product containing both acyl groups. The preparation of cellulose acetate butyrate and cellulose acetate propionate is described in more detail in U.S. Pat. Nos. 2,339,631 and 2,824,098.
In the preparation of ultrathin films, any cellulose ester capable of being dissolved in a mixture containing 1,2,3-trichloropropane, methylene chloride, and methanol can be employed. The preferred cellulose esters are cellulose acetate, cellulose triacetate, cellulose butyrate, cellulose propionate, cellulose acetate butyrate and cellulose acetate propionate. The most preferred ester is cellulose triacetate. The solvents used to form the casting solution are 1,2,3-trichloropropane, methylene chloride and methanol and are generally present at about a 85:52:13 to about a 100:45:5 ratio by volume and preferably about a 91:50:9 ratio. All three solvents must be present in the casting solution. If methanol is not present, the polymer solution has a tendency to gel before casting. Methylene chloride is employed so that the polymer solution will spread on the surface of water. The ratio of solvents given above should not be substantially varied. The reason is that if either the amount of methylene chloride or trichloropropane is reduced significantly, the casting solution will not spread on the surface of water.
The polymer is dissolved in the solvent mixture at a concentration of about two to about twelve percent, preferably about three to about seven percent and most preferably about four to about five percent based upon the total weight of solvents and polymer. Generally, the greater the amount of the polymer in the casting solution, the thicker the films that are prepared. Conversely, the lower the amount of polymer, the thinner the films will be. However, if the amount of polymer is too low, such as below about one percent by weight, it is very difficult to lift the films from the casting surface. The polymer is preferably dissolved by magnetically stirring the polymer and solvents for several hours (e.g. three to five hours) at room temperature.
Cellulose ester films may also be prepared from a mixed polymer solution containing a cellulose ester polymer and a minor amount of other polymers which are compatible in film form with the cellulose ester and which are capable of being dissolved in the casting solution. When other polymers are mixed with a cellulose ester, the amount of cellulose ester employed should be 80 percent or more by weight based upon the total weight of polymers dissolved in the polymeric solution.
Before the polymeric solution is cast into films, it is preferred to filter the solution using microfilters and/or membranes. Filtration of the polymer solution before casting substantially reduces imperfections in the cast films. For example, the solution can be suction filtered through glass microfiber filters and then passed through one or more Millipore membranes available from the Millipore Corporation. It is preferred to filter the solution through a 0.45 micron Millipore membrane. In order to force the solution through the membrane, it is usually necessary to apply pressure. For example, a Millipore stainless 47 mm pressure holder operated at a pressure up to 100 psi argon can be employed. The amount of pressure applied will depend upon the viscosity of the solution and the pore size of the membrane. Enough pressure to force the solution through the membrane is needed.
After filtration, the solution is cast on water at or near room temperature. As used herein, the term "water" includes aqueous solutions containing minor amounts (e.g., one percent or less by weight of the solution) of organic solvents (e.g., lower weight alcohols) the presence of which does not adversely affect the properties of the film cast of the solution. The addition of such organic solvents may facilitate the removal of the film from the water's surface. The water is contained in any suitable walled container. For example, an appropriate container is an aluminum container having dimensions of 12"×12"×3". Preferably, the walls of the container are sloped outwardly at about a 20 degree incline to reduce reflected surface waves which can damage the film. Such waves are produced when the polymeric solution is placed on the water's surface or by air currents and external vibrations. Most preferably, the inside walls of the container are teflon coated so that films are less likely to stick to the sides of the container.
The polymeric solution is cast by depositing a drop of the polymer solution upon the water's surface. The solution usually spreads over the surface of the water in three seconds or less. The solution is allowed to stand until a sufficient amount of the solvent has evaporated to form a free-standing film. As used herein, the term "free-standing film" refers to a film that has a physically stable shape and is dimensionally stable on its casting surface and can be removed from the casting surface without having to be supported over the entire surface area of the film. The time of evaporation generally is between 20 and 30 seconds and rarely more than 60 seconds.
After the solvent has evaporated, the film is lifted from the liquid surface using any suitable means, such as 2"×3", thin, aluminum plate having a 30 millimeter inner diameter hole in it and a handle on one end of the plate. When the aluminum plate touches the surface of the film, the film adheres to the aluminum plate and may readily be removed from the surface of the water.
The films of the instant invention are generally round, ultrathin, pinhole-free, uniform films and have a diameter of about six inches or more and a thickness of less than 400 angstroms, preferably about 160 angstroms or less and most preferably about 70 to about 160 angstroms. As used herein, the term "ultrathin film" refers to a film having a thickness of about 400 angstroms or less, and the term "pinhole-free film" refers to a film containing no holes more than one micron in diameter.
The films of this invention can be used as gas separation membranes and in end uses where a controlled release of drugs is needed.
The invention is illustrated by the following examples in which all percentages are by weight unless otherwise specified.
EXAMPLE 1
A polymer solution containing 4.7 percent by weight cellulose triacetate in a mixture of 91:50:9 by volume 1,2,3-trichloropropane:methylene chloride:methanol was prepared by dissolving the polymer in the solvent mixture. The cellulose triacetate polymer was KB-175 which is available from Celanese Corporation. KB-175 is a solvent castable, film grade, cellulose triacetate flake containing no chemical additives and has a viscosity at 6 percent weight/volume of 147±15 centipose, an acetyl value of 61.3±0.3 percent, a melting point of 287° C. and a molecular weight, M w , of about 90,000. The solution was prepared by magnetically stirring the solvents and the polymer at room temperature for about 5 hours.
After the polymer was dissolved in the solvent mixture, the polymer solution was filtered through a Duropore polyvinylidene fluoride membrane having a pore size of about 0.45 micron and available from the Millipore Corporation. A Millipore stainless 47 millimeter pressure holder operated at a pressure sufficient to force the solution through the membrane was employed.
After filtration, a drop of the polymer solution was deposited on water. The water was contained in a square aluminum container measuring 12"×12"×3", having teflon coated walls which were sloped away from the center at a 20 degree incline. The drop spread rapidly over the surface of the water to form a film having a diameter of about six inches. After 20 seconds, the film was lifted from the surface of the water using a 2"×3" aluminum plate having a 30 mm diameter hole in the middle and a handle attached at one end. The film was uniform and had a thickness of about 160 angstroms. Microscopic examination of the film disclosed no pinholes having a diameter of 1 micron or more.
EXAMPLE 2
Example 1 was repeated except that a 91:50 ratio of 1,2,3-trichloropropane to methylene chloride was employed. The casting solution gelled and could not be cast.
EXAMPLE 3
Example 1 was repeated except that a 91:9 ration of 1,2,3-trichloropropane to methanol was prepared. When a droplet of the casting solution was placed on water, the droplet would not spread to form a film.
EXAMPLE 4
Example 1 was repeated except that the amount of cellulose triacetate was about 5.0 percent by weight. The resulting film had a thickness of about 160 angstroms and had no microscopically observable holes having a diameter greater than one micron.
EXAMPLE 5
Example 1 was repeated except that a three percent by weight solution of cellulose triacetate was prepared and the solution was not filtered. The resulting film contained spots, had a thickness of about 85 angstroms and exhibited no macroscopic pinholes.
EXAMPLE 6
Example 1 was repeated except that the polymer solution contained three percent by weight of the cellulose triacetate polymer in a 91:25:25:9 by volume solvent mixture of 1,2,3-trichloropropane:methylene chloride:ethylene chloride:methanol. When a drop of the casting solution was placed on water, the droplet would not spread to form a film.
As can be seen, 1,2,3-trichloropropane, methylene chloride and methanol must all be present in order to prepare pinhole-free, ultrathin, cellulose ester films. | Disclosed herein are pinhole-free, ultrathin, free-standing cellulose ester films having thicknesses of 400 angstroms or less and a process to prepare them. The films find particular utility in separatory applications. | 2 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a magnetic recording medium using a flexible polymer support member such as magnetic tape, flexible disk, etc. and a rigid support member. In particular, the invention relates to high capacity magnetic tape, high capacity flexible disk, hard disk, etc., which can be used for high-density magnetic recording.
[0002] In recent years, to cope with the handling of large-capacity image information due to extensive propagation of information technology such as Internet, a large-capacity hard disk is used in personal computer. In order to back up large-capacity information stored in the hard disk or to try to use the information in another computer, various types of removable recording medium are used.
[0003] Flexible magnetic recording medium such as magnetic tape, flexible disk, etc. is characterized in that the time required for recording and reading of information is short as in case of hard disk and the devices required for recording and reading of the information are also designed in small size. For this reason, the magnetic tape and the flexible disk are used for the purpose of backing up the computer or for storing large capacity data as a typical removable type recording medium. There are now strong demands on a type of magnetic recording medium, which can store large-capacity data in small number of magnetic tapes and flexible disks.
[0004] In the magnetic recording medium using a flexible polymer support member such as magnetic tape, flexible disk, etc., a coating type magnetic recording medium and a deposition type magnetic recording medium are used. In the coating type magnetic recording medium, magnetic particles containing metals such as iron, cobalt, etc. on a substrate are dispersed in a polymer binder and is coated. In the deposition type magnetic recording medium, a cobalt alloy is deposited under vacuum condition and a film is formed.
[0005] Compared with the coating type magnetic recording medium, the deposition type magnetic recording medium is more suitable for high-density recording. The magnetic layer of the flexible type magnetic recording medium where metal thin film is formed by vacuum deposition causes more noises compared with ferromagnetic metal thin film formed by sputtering of cobalt alloy as used in the hard disk. In the head for high-density recording using magnetic resistance element, sufficient electromagnetic transfer characteristics cannot be obtained, and it is not suitable for high-density recording.
[0006] In this connection, several studies have been reported, in which attempts has been made to prepare a ferromagnetic metal thin film tape by sputtering as in the case of hard disk, but it is not yet used in practical application.
[0007] The reasons are as follows: In the manufacture of hard disk, a substrate is heated up to about 200° C. during sputtering. If this method is applied in the manufacture of magnetic tape or flexible disk, polyethylene terephthalate or polyethylene naphthalate commonly used as a base material for magnetic tape or flexible disk does not have sufficient heat-resistant property and is easily deformed. Even when aromatic polyamide film with high heat-resistant property is used, dimensional changes such as thermal expansion, thermal shrinking, humidity expansion, etc. of the film occur during the manufacturing process. Thus, it has been difficult to manufacture a magnetic tape with less possibility of deformation.
[0008] In case of the flexible disk, a magnetic layer is formed using a band-like base material similar to the magnetic tape. Then, it is punched to a predetermined disk shape, and this causes the problems similar to those as described above.
[0009] It is an object of the present invention to provide a magnetic recording medium, which is useful as a magnetic recording medium using magnetic tape, flexible disk, etc. and uses a rigid material as a support member, and which can be used as a removable type magnetic recording medium suitable for high-density recording.
[0010] It is another object of the present invention to provide a magnetic recording medium with excellent characteristics, which comprises a specific primer layer at least on one surface of a nonmagnetic substrate.
SUMMARY OF THE INVENTION
[0011] The present invention provides a magnetic recording medium, which comprises a magnetic layer at least on one surface of a flexible polymer support member, said magnetic layer comprises a cobalt-containing ferromagnetic metal alloy and a nonmagnetic oxide.
[0012] Also, the present invention provides the magnetic recording medium as described above, wherein said magnetic layer comprises a ferromagnetic metal alloy containing at least cobalt, platinum and chromium, and a nonmagnetic material.
[0013] Further, the present invention provides a magnetic recording medium, which comprises a chromium-containing primer layer and a magnetic layer at least on one surface of a nonmagnetic support member, said chromium-containing primer layer contains chromium and at least one type of element selected from a group of cobalt, beryllium, osmium, rhenium, titanium, zinc, tantalum, aluminum, molybdenum, tungsten, vanadium, iron, antimony, iridium, ruthenium, rhodium, platinum, palladium, silicon, and zirconium, and said magnetic layer comprises a ferromagnetic metal alloy containing at least cobalt, platinum and chromium, and a nonmagnetic material.
[0014] Also, the present invention provides a magnetic recording medium, which comprises a primer layer containing at least ruthenium, and a magnetic layer at least on one surface of a nonmagnetic substrate, said magnetic layer comprising a ferromagnetic metal alloy containing at least cobalt, platinum and chromium, and a nonmagnetic material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 represents cross-sectional views, each showing an embodiment of the present invention;
[0016] FIG. 2 represents cross-sectional views, each showing another embodiment of the present invention;
[0017] FIG. 3 represents cross-sectional views, each showing still another embodiment of the present invention;
[0018] FIG. 4 represents cross-sectional views, each showing a magnetic layer of the magnetic recording medium shown in FIG. 3 ;
[0019] FIG. 5 represents cross-sectional views, each showing still another embodiment of the present invention;
[0020] FIG. 6 represents cross-sectional views, each showing a magnetic layer of the magnetic recording shown in FIG. 5 ;
[0021] FIG. 7 is a schematical drawing to explain a method for forming a magnetic layer on a flexible polymer support member; and
[0022] FIG. 8 is a schematical drawing to explain an example of CVD apparatus utilizing high frequency plasma and applicable to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] In the magnetic recording medium of the present invention, a magnetic layer comprising a cobalt-containing ferromagnetic metal alloy and a nonmagnetic oxide is provided at least on one surface of a flexible polymer support member. This can be produced by methods such as sputtering even when the temperature of the flexible polymer support member is at room temperature. Thus, a magnetic recording medium with excellent characteristics can be produced even when a flexible polymer support member may be used as a base material, which is deformable when heated at high temperature.
[0024] Also, by forming a specific primer layer on the nonmagnetic support member, it is possible to produce a magnetic recording medium, which has a magnetic layer with excellent characteristics.
[0025] Description will be given below on the present invention referring to the drawings.
[0026] FIG. 1 represents cross-sectional views, each showing an embodiment of the present invention.
[0027] FIG. 1 (A) is a drawing to explain an embodiment of the present invention where the magnetic recording medium is a magnetic tape, and it is a cross-sectional view showing a part of it.
[0028] A magnetic tape 11 comprises a magnetic layer 15 formed on a band-like flexible polymer support member 12 , and the magnetic layer 15 comprises a cobalt-containing ferromagnetic metal alloy 18 and a nonmagnetic oxide 19 . On the magnetic layer 15 , a protective layer 16 is formed, which prevents deterioration of the magnetic layer due to oxidation and protects from wearing caused by the contact with a head or a sliding member. Also, a lubricating layer 17 is provided on the protective layer 16 for the purpose of improving running durability and corrosion-resistant property.
[0029] As shown in FIG. 1 (B), an undercoating layer 13 is arranged on the surface of the flexible polymer support member 12 in addition to the arrangement shown in FIG. 1 (A). This undercoating layer 13 makes it possible to adjust surface property of the flexible polymer support member 12 and to prevent a gas generated from the flexible polymer support member 12 from reaching the magnetic layer 15 . Further, a primer layer 14 is provided, which controls crystal orientation of the ferromagnetic metal on the magnetic layer 15 and to attain better recording characteristics.
[0030] In the magnetic tape shown in FIG. 1 (B), crystal orientation of the ferromagnetic metal is improved by the primer layer. Compared with the one shown in FIG. 1 (A), a tape with much better characteristics can be obtained.
[0031] The magnetic tape can be used in form of an open reel or as a tape incorporated in a cartridge.
[0032] FIG. 2 represents cross-sectional views, each showing another embodiment of the present invention.
[0033] FIG. 2 (A) is a drawing to explain a case where the magnetic recording medium is a flexible disk.
[0034] A flexible disk 21 comprises magnetic layers 26 each formed on each surface of a flexible polymer support member 22 . Each of the magnetic layers 26 comprises a cobalt-containing ferromagnetic metal alloy 29 and a nonmagnetic material 30 . On each of the magnetic layers 26 , a protective layer 27 is formed, which prevents deterioration of the magnetic layer due to oxidation and protects from wearing caused by the contact with a head or a sliding member. Also, on the protective layer 27 , a lubricating layer 28 is provided with the purpose of improving running durability and corrosion-resistant property. At the center of the flexible disk, there is provided engaging means 31 to make the flexible disk engaged on a flexible disk drive.
[0035] In the magnetic recording medium shown in FIG. 2 (B), an undercoating layer 23 is arranged on the surface of the flexible polymer support member 22 for the purpose of adjusting surface characteristics of the flexible polymer support member 22 and of preventing a gas generated from the flexible polymer support member 22 from reaching the magnetic layer 26 . Further, there is provided a primer layer 25 , which controls crystal orientation of the ferromagnetic metal formed on the magnetic layer 26 and to improve recording characteristics.
[0036] Compared with the flexible disk shown in FIG. 2 (A), the flexible disk shown in FIG. 2 (B) has better crystal orientation of the ferromagnetic metal due to the primer layer and has higher magnetic characteristics.
[0037] The magnetic layer formed on the magnetic recording medium of the present invention has a ferromagnetic metal thin-film magnetic layer, which comprises a cobalt-containing ferromagnetic metal alloy and a nonmagnetic oxide. As a result, high-density recording as that of a hard disk can be achieved. This makes it possible to obtain a removable type magnetic recording medium with high capacity. The ferromagnetic metal thin film comprising a cobalt-containing ferromagnetic metal alloy and a nonmagnetic oxide has been proposed for the application in hard disk. The product produced by the method similar to the method described in JP-A-07-311929 (U.S. Pat. No. 5,679,473) or JP-A-05-73880 (U.S. Pat. No. 5,658,680) may be used.
[0038] The magnetic layer in the magnetic recording medium of the present invention may be the so-called vertical magnetic recording film, which has an axis of easy magnetization running perpendicularly to the surface of the magnetic layer, or it may be an in-plane magnetic recording film, which has an axis of easy magnetization in horizontal direction. The direction of the axis of easy magnetization can be controlled by the material and the crystal structure of the primer layer and by composition and film-forming condition of the magnetic film.
[0039] The magnetic layer comprises a cobalt-containing ferromagnetic metal alloy and a nonmagnetic oxide. Because fine ferromagnetic metal alloy crystals are evenly dispersed, high coercive force can be achieved and dispersion property is evenly distributed. As a result, a magnetic recording medium with lower noise can be obtained.
[0040] As the cobalt-containing ferromagnetic metal alloy, an alloy of Co with elements such as Cr, Ni, Fe, Pt, B, Si, Ta, etc. may be used. It is preferable to use Co—Pt, Co—Cr, Co—Pt—Cr, Co—Pt—Cr—Ta, Co—Pt—Cr—B, etc. because better magnetic recording characteristics can be obtained.
[0041] For instance, a preferable element composition for a CoPtCr alloy to be used for in-plane recording is a composition of the following elements in the following range: Co in 65-80 atom %, Pt in 5-20 atom %, and Cr in 10-20 atom %. When a nonmagnetic element such as B, Ta, etc. is added, it may be added in such manner that it is substituted with Pt or Cr within the range of 10 atom %. As a preferable composition of CoPt alloy to be used for vertical recording, a composition of elements in the following range may be used: Co in 70-85 atom and Pt in 15-30 atom %. The higher the content of Co is, the more the magnetization is increased, and reproduced signal output is increased. Noise is increased at the same time. On the other hand, the higher the content of nonmagnetic elements such as Cr, Pt, etc. is, the more the magnetization is decreased, but coercive force is increased. Thus, reproduced signal output is decreased while noise is decreased. Therefore, it is preferable to adjust mixing ratio of these elements depending on the magnetic head used and the equipment in use.
[0042] Anisotropy of magnetization can be adjusted by argon pressure during film formation in addition to the composition. It is preferable to determine the anisotropy by the primer layer as described below. In case the primer layer is not used or in case amorphous material is used, the magnetic layer is more easily oriented in vertical direction. When Cr or its alloy or Ru or its alloy is used, it is more easily oriented in in-plane direction.
[0043] As the nonmagnetic oxide, an oxide of Si, Zr, Ta, B, Ti, Al, etc. may be used. When an oxide of silicon is used, the best recording characteristics can be obtained.
[0044] Mixing ratio of the cobalt-containing ferromagnetic metal alloy and the nonmagnetic oxide is preferably in the following range: Ferromagnetic metal alloy:nonmagnetic oxide=95:5 to 80:20 (atom ratio), or more preferably in the range of 90:10 to 85:15. By setting the mixing ratio within this range, sufficient separation can be kept between magnetic particles. This eliminates the decrease of thermal decay, and amount of magnetization can be maintained at high level. As a result, high signal output can be attained.
[0045] In the magnetic layer, which is a mixture of the cobalt-containing ferromagnetic metal alloy and the nonmagnetic oxide, its thickness is preferably in the range of 10 nm to 60 nm, or more preferably in the range of 20 nm to 40 nm. In the magnetic layer with the thickness in this range, noise can be decreased and higher output can be obtained.
[0046] As a method for forming the magnetic layer, which comprises the cobalt-containing ferromagnetic metal alloy and the nonmagnetic material such as nonmagnetic oxide, vacuum film-forming method such as vacuum deposition method, sputtering method, etc. may be used. Above all, the sputtering method can form thin film of good quality, and it is suitable for the purpose of the present invention. As the sputtering method, DC sputtering method or RF sputtering method can be used. In the sputtering method, it is preferable to use a web sputtering apparatus, which can continuously form the film on a continuous film.
[0047] As a gas to be used in atmosphere during sputtering, argon may be used, while other type of rare gas may be used. A slight quantity of oxygen may be introduced to adjust oxygen content in the nonmagnetic oxide.
[0048] In particular, when a magnetic layer is produced, which comprises the cobalt-containing ferromagnetic metal alloy and the nonmagnetic oxide, and the sputtering method is used for this purpose as in the present invention, two types of targets, i.e. a ferromagnetic metal alloy target and a nonmagnetic oxide target may be used, and co-sputtering method with these two targets may be adopted. If a mixture target is used, which is a uniform mixture of the ferromagnetic metal alloy and the nonmagnetic oxide and which concurs with composition ratio of the ferromagnetic metal alloy and the nonmagnetic oxide to be produced, a magnetic layer with uniformly dispersed ferromagnetic metal alloy can be obtained. This mixture target can be produced by hot press method.
[0049] Description will be given now on a case where the magnetic recording medium is a magnetic tape.
[0050] As the flexible support member to be used in the magnetic tape, a synthetic resin film is used. More concretely, a synthetic resin film comprising aromatic polyimide, aromatic polyamide, aromatic polyamideimide, polyether ketone, polyether sulfone, polyether imide, polysulfone, polyphenylene sulfide, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, triacetate cellulose, fluororesin, etc. may be used. According to the present invention, high recording characteristics can be attained without heating the substrate. Thus, it is preferable to use polyethylene terephthalate or polyethylene naphthalate, which has high surface property and is easily available.
[0051] The thickness of the flexible polymer support member is preferably in the range of 3 μm to 20 μm, or more preferably in the range of 4 μm to 12 μm. If the thickness of the flexible polymer support member is thinner than 3 μm, the strength is insufficient, and this often leads to breakage or edge defect. On the other hand, if the thickness of the flexible polymer support member is thicker than 20 μm, the length of the magnetic tape to be wound up per one set of the magnetic tape will be shorter, and this results in lower volume recording density. Also, rigidity is increased. As a result, the contact to the magnetic head, i.e. follow-up property, is aggravated.
[0052] To ensure good recording and reading of information through contact with the magnetic head, it is preferable that the surface of the flexible polymer support member is as smooth as possible. Surface irregularities of the flexible polymer support member causes extreme decrease in the recording and reproduction characteristics of signal.
[0053] More concretely, when the undercoating layer as described later is used, surface roughness measured using a light interference type surface roughness meter is preferably in the range of 5 nm in central surface average roughness (SRa), or more preferably within 2 nm. Projection height measured using a feeler type roughness meter is within 1 μm, or more preferably within 0.1 μm. When the undercoating layer is not used, central surface average roughness (SRa) measured by a light interference type surface roughness meter is within 3 nm, or more preferably within 1 nm. Projection height measured by a feeler type roughness meter is within 0.1 μm, or more preferably within 0.06 μm.
[0054] To ensure better surface flatness and higher gas shut-off property, it is preferable to provide an undercoating layer on the surface of the flexible polymer support member. Because the magnetic layer is formed by the method such as sputtering, the undercoating layer preferably has high heat-resistant property. As the material of the undercoating layer, polyimide resin, polyamidemide resin, silicone resin, fluororesin, etc. may be used. It is more preferable to use solvent-soluble type polyimide resin, thermosetting type polyimide resin, or thermosetting type silicone resin because better smoothening effect can be attained. The thickness of the undercoating layer is preferably in the range of 0.1 μm to 3.0 μm.
[0055] As the thermosetting silicone resin, a silicone resin produced through polymerization by sol-gel method using silicon compound with organic radical introduced in it may be optimally used. In this silicone resin, a part of the bond of silicon dioxide is substituted with an organic radical, and it has much higher heat-resistant property than silicone rubber and has higher flexibility than silicon dioxide film. Accordingly, when a resin film is formed on a polymer support member comprising flexible film, cracking or peeling hardly occurs. Also, a raw material monomer can be directly coated on the flexible polymer support member and can be hardened. Moreover, the monomer is dissolved in a general-type organic solvent and can be coated. This makes it possible to prevent distortion or warping avoiding surface irregularities and higher smoothening effect can be provided. Further, condensation polymerization reaction occurs from relatively low temperature when a catalyst such as acid or chelating agent is added. Thus, it can be hardened within short time, and resin film can be formed by using a general-purpose coating apparatus.
[0056] The thermosetting silicone resin has high gas shut-off property. As a result, it can shut off the gas, which is generated from the flexible polymer support member during the formation of the magnetic layer or the primer layer and which impairs crystallization property and orientation of the magnetic layer or the primer layer, and it is suitable for this purpose.
[0057] On the surface of the undercoating layer, it is preferable to provide micro-projections (texture) in order to decrease actual contact area between the sliding member such as magnetic tape, guide pole, etc. and also to ensure the improvement of the sliding property. By providing micro-projections, the handling of the flexible polymer support member can be made much easier. To form the micro-projections, a method to coat spherical silica particles or a method to coat emulsion and to form projections of organic substance may be used. To maintain heat-resistant property of the undercoating layer, it is preferable to coat the spherical silica particles and to form micro-projections.
[0058] The height of the micro-projection is preferably in the range of 5 nm to 60 nm, or more preferably in the range of 10 nm to 30 nm. If the micro-projections are too high, signal recording and reproduction characteristics are decreased due to spacing loss of the recording and reproducing head and the magnetic recording medium. If the micro-projections are too low, the effect to improve the sliding property is decreased. The density of the micro-projections is preferably in the range of 0.1 to 100 projections/μm 2 , or more preferably in the range of 1 to 10 projections/μm 2 . If the density of the micro-projections is too low, the effect to improve the sliding property is decreased. If the density is too high, high projections are increased due to the increase of aggregated particles, and this leads to deterioration of the recording and reproducing characteristics.
[0059] The micro-projections can be fixed on the surface of the support member by using a binder. As the binder, it is preferable to use a resin with high heat-resistant property. As the resin with high heat-resistant property, it is preferable to use a solvent-soluble type polyimide resin, thermosetting type polyimide resin, or thermosetting type silicone resin.
[0060] It is preferable to provide a primer layer under the magnetic layer. As the material of the primer layer, Cr or an alloy of Cr with a metal element selected from Ti, Si, W, Ta, Zr, Mo, Nb, etc. or Ru, C, etc. may be used. These substances may be used alone or in combination of two or more. By the use of the primer layer, it is possible to improve orientation property of the magnetic layer, and recording characteristics can be improved. The thickness of the primer layer is preferably in the range of 10 nm to 200 nm, or more preferably in the range of 20 nm to 100 nm.
[0061] In particular, it is preferable that the magnetic layer is designed in column-like form by the primer layer. By producing the magnetic layer in form of column, separation structure between the ferromagnetic metals is stabilized. Higher coercive force can be obtained, and higher output can be achieved. The ferromagnetic metal can be more evenly distributed, and a magnetic recording medium with lower noise can be prepared.
[0062] Further, to improve crystalline property of the primer layer, a seed layer may be provided between the primer layer and the flexible polymer support member. As the seed layer, Ta, Ta—Si, Ni—P, Ni—Al, etc. may be used.
[0063] When anisotropy of magnetization is set to vertical direction, a soft magnetic layer may be provided between the magnetic layer and the flexible polymer support member. By providing the soft magnetic layer, it is possible to have better electromagnetic transfer characteristics when a vertical recording head such as single magnetic pole head is used. As the soft magnetic material, Permalloy or Sendust may be used. Its thickness is preferably in the range of 30 nm to 500 nm.
[0064] A protective layer is arranged on the magnetic layer. The protective layer is provided to prevent corrosion of metal materials contained in the magnetic layer, to avoid wearing due to pseudo-contact or contact sliding between the magnetic head and the magnetic tape, and to ensure better running durability and higher corrosion-resistant property. As the protective layer, oxides such as silica, alumina, titania, zirconia, cobalt oxide, nickel oxide, etc., nitrides such as titanium nitride, silicon nitride, boron nitride, etc., carbides such as silicon carbide, chromium carbide, boron carbide, etc., carbon such as graphite, amorphous carbon, etc. may be used.
[0065] As the protective layer, it is preferable to use a hard film, which has hardness equal to or higher than the hardness of the magnetic head material and which is hardly subjected to seizure during sliding operation and has stable and continuous effect because such material can maintain good sliding durability. Also, the material with fewer pin holes is preferably used because it has higher corrosion-resistant property. As such protective film, a hard carbon film called “diamond-like carbon” (DLC) produced by CVD method is used. The protective layer may comprise two or more types of thin films having different property and laminated one upon another. For instance, a hard carbon protective film to improve the sliding characteristics may be provided on surface side, and a nitride protective film such as silicon nitride to improve corrosion-resistant property may be provided on the magnetic recording layer side. This makes it possible to provide both corrosion-resistant property and high durability.
[0066] On the protective layer, a lubricating layer is provided to ensure high running durability and good corrosion-resistant property. As the lubricant, hydrocarbon type lubricant, fluorine type lubricant, extreme-pressure additive, etc. as already known in the art may be used.
[0067] As the hydrocarbon type lubricant, carboxylic acids such as stearic acid, oleic acid, etc., esters such as butyl stearate, sulfonic acids such as octadecyl sulfonic acid, phosphoric acid esters such as monooctadecyl phosphate, alcohols such as stearyl alcohol, oleyl alcohol, etc., carboxylic acid amide such as stearic acid amide, etc., or amines such as stearyl amine may be used.
[0068] As the fluorine type lubricant, a lubricant prepared by substituting a part or all of the alkyl groups in the hydrocarbon type lubricant by fluoroalkyl group or perfluoropolyether group may be used. As the perfluoro-polyether group, perfluoromethylene oxide polymer, perfluoroethylene oxide polymer, perfluoro-n-propylene oxide polymer (CF 2 CF 2 CF 2 O) n , perfluoroisopropylene oxide polymer (CF(CF 3 )CF 2 O) n or copolymer of these compounds may be used.
[0069] More concretely, perfluoromethylene-perfluoroethylene copolymer (Trade name: Fomblin Z-Dol; manufactured by Ausimont Co., Ltd.) having hydroxyl group at the molecular weight terminal may be used.
[0070] As the extreme-pressure additive, phosphoric acid esters such as trilauryl phosphate, phosphorous acid esters such as trilauryl phosphite, thiophosphorous acid esters such as trilauryl trithiophosphite., sulfur type extreme-pressure agent such as dibenzyl disulfide may be used.
[0071] The above lubricants may be used alone or in combination of two or more. A solution obtained by dissolving the lubricant in organic solvent may be coated on the surface of the protective layer by spin coating method, wire bar coating method, gravure coating method, dip coating method, etc. or the lubricant may be attached on the surface of the protective layer by vacuum deposition method. The amount of coating of the lubricant is preferably in the range of 1 to 30 mg/m 2 , or more preferably in the range of 2 to 20 mg/m 2 .
[0072] To have higher corrosion-resistant property, it is preferable to use a rust-preventive agent simultaneously. As the rust-preventive agent to be used in the present invention, nitrogen-containing heterocyclic compounds such as benzotriazole, benzimidazole, purine, pyrimidine, etc., derivatives prepared by introducing alkyl side-chain to the base nucleus, nitrogen- or sulfur-containing hetero-cyclic compounds and derivatives such as benzothiazole, 2-mercaptobenzothiazole, tetrazaindene cyclic compound, or thiouracil compound may be used. These rust-preventive agents may be mixed with the lubricant and coated on the protective layer. Or, it may coated on the protective layer before the coating of the lubricant, and then, the lubricant may be coated on it. The amount of coating of the rust-preventive agent is preferably in the range of 0.1 to 10 mg/m 2 , or more preferably in the range of 0.5 to 5 mg/m 2 .
[0073] On the surface of the flexible polymer support member opposite to the surface where the magnetic layer is formed, it is preferable to provide a back-coating layer. The back-coating layer provides lubricating effect to prevent wearing of the backside of the magnetic recording medium when the magnetic recording medium is slid against the sliding member. By adding the lubricant or the rust-preventive agent to be used in the lubricating layer to the back-coating layer, the lubricant or the rust-preventive agent is supplied from the back-coating side to the magnetic layer side, and this makes it possible to maintain corrosion-resistant property of the magnetic layer for long time. By adjusting pH value of the back-coating layer itself, it is possible to increase the corrosion-resistant property of the magnetic layer further.
[0074] The back-coating layer may be prepared as follows: Nonmagnetic powder such as carbon black, calcium carbonate, alumina, etc. and resin binder such as polyvinyl chloride or polyurethane, and further, lubricant or hardening agent are dispersed in an organic solvent. Then, this solution is coated by gravure coating method or wire bar coating method and is dried.
[0075] To apply the rust-preventive agent or the lubricant to the back-coating layer, it may be dissolved in the solution as described above or it may be coated directly on the back-coating layer.
[0076] Next, description will be given below on a case where the magnetic recording medium is a flexible disk. In order to avoid shock when the magnetic head is brought into contact with the flexible disk, the support member of the flexible disk comprises a synthetic resin film with flexibility, i.e. a flexible polymer support member. As the synthetic resin film, a synthetic resin film comprising aromatic polyimide, aromatic polyamide, aromatic polyamideimide, polyether ketone, polyether sulfone, polyether imide, polysulfone, polyphenylene sulfide, polyethylene naphthalate, polyethylene terephthalate, polycarbonate, triacetate cellulose, fluororesin, etc. may be used. According to the present invention, high recording characteristics can be attained without heating the substrate. Thus, it is preferable to use polyethylene terephthalate or polyethylene naphthalate, which has high surface property and is easily available.
[0077] Or, two or more synthetic resin films may be laminated one upon another and this may be used as the flexible polymer support member. By using a laminated film with two or more synthetic resin films laminated one upon another, it is possible to eliminate or alleviate warping or undulation due to the flexible polymer support member itself. As a result, vulnerability of the magnetic recording layer can be extremely improved, which may be caused when the surface of the magnetic recording medium collides with the magnetic head.
[0078] As the methods to laminate the flexible films, a roll laminating method to use hot roll, a plane lamination method by plane hot press, a dry laminating method to coat an adhesive agent on the surface and to laminate, or a method to use adhesive sheet fabricated in form of sheet in advance may be used. When an adhesive agent is used for lamination, hot melt adhesive agent, thermosetting adhesive agent, UV-setting adhesive agent, EB-setting adhesive agent, adhesive sheet, or anaerobic adhesive agent may be used.
[0079] The thickness of the flexible polymer support member is preferably in the range of 10 μm to 200 μm, or more preferably in the range or 20 μm to 150 μm, or most preferably in the range of 30 μm to 100 μm. If the thickness of the flexible polymer support member is thinner than 10 μm, stability during high-speed rotation is decreased and surface deviation is increased. On the other hand, if the thickness of the flexible polymer support member is thicker than 200 μm, rigidity is increased during rotation, and it is difficult to avoid the shock at the moment of contact, and this may cause jumping of the magnetic head.
[0080] Further, the value of the toughness of the flexible polymer support member as expressed in the formula given below when b=10 mm is preferably in the range of 4.9 MPa to 19.6 MPa (0.5 kgf/mm 2 to 2.0 kgf/mm 2 ), or more preferably in the range of 6.9 MPa to 14.7 MPa (0.7 kgf/mm 2 to 1.5 kgf/mm 2 ):
Toughness of flexible polymer support member= Ebd 3 /12
where E is Young's modulus, b is film width, and d is film thickness.
[0082] To ensure good recording and reading of information through contact with the magnetic head, it is preferable that the surface of the flexible polymer support member is as smooth as possible. Surface irregularities of the flexible polymer support member causes extreme decrease in the recording and reproduction characteristics of signal.
[0083] More concretely, when the undercoating layer as described later is used, surface roughness measured using a light interference type surface roughness meter is preferably in the range of 5 nm in central surface average roughness (SRa), or more preferably within 2 nm. Projection height measured using a feeler type roughness meter is within 1 μm, or more preferably within 0.1 μm. When the undercoating layer is not used, central surface average roughness (SRa) measured by a light interference type surface roughness meter is within 3 nm, or more preferably within 1 nm. Projection height measured by a feeler type roughness meter is within 0.1 μm, or more preferably within 0.06 μm.
[0084] To ensure better surface flatness and higher gas shut-off property, it is preferable to provide an undercoating layer on the surface of the flexible polymer support member. Because the magnetic layer is formed by the method such as sputtering, the undercoating layer preferably has high heat-resistant property. As the material of the undercoating layer, polyimide resin, polyamidemide resin, silicone resin, fluororesin, etc. may be used. It is more preferable to use thermosetting type polyimide resin, or thermosetting type silicone resin because better smoothening effect can be attained. The thickness of the undercoating layer is preferably in the range of 0.1 μm to 3.0 μm. When other resin film is laminated on the support member, the undercoating layer may be prepared before laminating, or the undercoating layer may be prepared after laminating.
[0085] As the thermosetting polyimide resin, a polyimide resin produced by thermal polymerization of imide monomer having two or more terminal unsaturated radicals in the molecule (for instance, bisarylnadiimide (BANI; manufactured by Maruzen Petrochemical Co., Ltd.) is preferably used. This imide monomer can be produced through thermal polymerization at relatively low temperature after it has been coated in the state of monomer on the surface of the support member. For this reason, the raw material, i.e. monomer, can be directly coated and hardened on the support member. Also, this imide monomer can be dissolved in a general-purpose organic solvent and used. It has high productivity and workability and has lower molecular weight and lower solution viscosity. Thus, it is resistant to distortion or warping caused by surface irregularities when coating, and it can provide high smoothening effect.
[0086] As the thermosetting silicone resin, a silicone resin produced through polymerization by sol-gel method using silicon compound with organic radical introduced in it may be optimally used. In this silicone resin, a part of the bond of silicon dioxide is substituted with an organic radical, and it has much higher heat-resistant property than silicone rubber and has higher flexibility than silicon dioxide film. Accordingly, when a resin film is formed on a polymer support member comprising flexible film, cracking or peeling hardly occurs. Also, a raw material monomer can be directly coated on the flexible polymer support member and can be hardened. The raw material, i.e. monomer, can be directly coated on the flexible polymer support member and can be hardened. As a result, a general-purpose solvent can be used. This makes it possible to prevent distortion or warping caused by surface irregularities and provides high smoothening effect. Further, condensation polymerization reaction occurs from relatively low temperature when a catalyst such as acid or chelating agent is added. Thus, it can be hardened within short time, and resin film can be formed by using a general-purpose coating apparatus.
[0087] The thermosetting silicone resin has high gas shut-off property. As a result, it can shut off the gas, which is generated from the flexible polymer support member during the formation of the magnetic layer or the primer layer and which impairs crystallization property and orientation of the magnetic layer or the primer layer, and it is suitable for this purpose.
[0088] On the surface of the undercoating layer, it is preferable to provide micro-projections (texture) in order to decrease actual contact area between the sliding members such as magnetic tape, guide pole, etc. and also to ensure the improvement of the sliding property. By providing micro-projections, the handling of the flexible polymer support member can be made much easier. To form the micro-projections, a method to coat spherical silica particles or a method to coat emulsion and to form projections of organic substance may be used. To maintain heat-resistant property of the undercoating layer, it is preferable to coat the spherical silica particles and to form micro-projections.
[0089] The height of the micro-projection is preferably in the range of 5 nm to 60 nm, or more preferably in the range of 10 nm to 30 nm. If the micro-projections are too high, signal recording and reproduction characteristics are decreased due to spacing loss of the recording and reproducing head and the magnetic recording medium. If the micro-projections are too low, the effect to improve the sliding property is decreased. The density of the micro-projections is preferably in the range of 0.1 to 100 projections/μm 2 , or more preferably in the range of 1 to 10 projections/μm 2 . If the density of the micro-projections is too low, the effect to improve the sliding property is decreased. If the density is too high, high projections are increased due to the increase of aggregated particles, and this leads to deterioration of the recording and reproducing characteristics.
[0090] The micro-projections can be fixed on the surface of the support member by using a binder. As the binder, it is preferable to use a resin with high heat-resistant property. As the resin with high heat-resistant property, it is preferable to use a solvent-soluble type polyimide resin, thermosetting type polyimide resin, or thermosetting type silicone resin.
[0091] It is preferable to provide a primer layer under the magnetic layer. As the material of the primer layer, Cr or an alloy of Cr with a metal element selected from Ti, Si, W, Ta, Zr, Mo, Nb, etc. or Ru, C, etc. may be used.
[0092] In particular, it is preferable that the magnetic layer is designed in column-like form by the primer layer. By producing the magnetic layer in form of column, separation structure between the ferromagnetic metals is stabilized. Higher coercive force can be obtained, and higher output can be achieved. The ferromagnetic metal can be more evenly distributed, and a magnetic recording medium with lower noise can be prepared.
[0093] These substances may be used alone or in combination of two or more. By the use of the primer layer, it is possible to improve orientation property of the magnetic layer, and recording characteristics can be improved. The thickness of the primer layer is preferably in the range of 10 nm to 200 nm, or more preferably in the range of 20 nm to 100 nm.
[0094] Further, to improve crystalline property of the primer layer, a seed layer may be provided between the primer layer and the flexible polymer support member. As the seed layer, Ta, Ta—Si, Ni—P, Ni—Al, etc. may be used.
[0095] When anisotropy of magnetization is set to vertical direction, a soft magnetic layer may be provided between the magnetic layer and the flexible polymer support member. By providing the soft magnetic layer, it is possible to have better electromagnetic transfer characteristics when a vertical recording head such as single magnetic pole head is used. As the soft magnetic material, Permalloy or Sendust may be used. Its thickness is preferably in the range of 30 nm to 500 nm.
[0096] A protective layer is arranged on the magnetic layer. The protective layer is provided to prevent corrosion of metal materials contained in the magnetic layer, to avoid wearing due to pseudo-contact or contact sliding between the magnetic head and the magnetic tape, and to ensure better running durability and higher corrosion-resistant property. As the protective layer, oxides such as silica, alumina, titania, zirconia, cobalt oxide, nickel oxide, etc., nitrides such as titanium nitride, silicon nitride, boron nitride, etc., carbides such as silicon carbide, chromium carbide, boron carbide, etc., carbon such as graphite, amorphous carbon, etc. may be used.
[0097] As the protective layer, it is preferable to use a hard film, which has hardness equal to or higher than the hardness of the magnetic head material and which is hardly subjected to seizure during sliding operation and has stable and continuous effect because such material can maintain good sliding durability. Also, the material with fewer pin holes is preferably used because it has higher corrosion-resistant property. As such protective film, a hard carbon film called “diamond-like carbon” (DLC) produced by CVD method is used. The protective layer may comprise two or more types of thin films having different property and laminated one upon another. For instance, a hard carbon protective film to improve the sliding characteristics may be provided on surface side, and a nitride protective film such as silicon nitride to improve corrosion-resistant property may be provided on the magnetic recording layer side. This makes it possible to provide both corrosion-resistant property and high durability.
[0098] On the protective layer, a lubricating layer is provided to ensure high running durability and good corrosion-resistant property. As the lubricant, hydrocarbon type lubricant, fluorine type lubricant, extreme-pressure additive, etc. as already known in the art may be used.
[0099] As the hydrocarbon type lubricant, carboxylic acids such as stearic acid, oleic acid, etc., esters such as butyl stearate, sulfonic acids such as octadecyl sulfonic acid, phosphoric acid esters such as monooctadecyl phosphate, alcohols such as stearyl alcohol, oleyl alcohol, etc., carboxylic acid amide such as stearic acid amide, etc., or amines such as stearyl amine may be used.
[0100] As the fluorine type lubricant, a lubricant prepared by substituting a part or all of the alkyl groups in the hydrocarbon type lubricant by fluoroalkyl group or perfluoropolyether group may be used. As the perfluoro-polyether group, perfluoromethylene oxide polymer, perfluoroethylene oxide polymer, perfluoro-n-propylene oxide polymer (CF 2 CF 2 CF 2 O) n , perfluoroisopropylene oxide polymer (CF(CF 3 )CF 2 O) n or copolymer of these compounds may be used.
[0101] More concretely, perfluoromethylene-perfluoroethylene copolymer (Trade name: Fomblin Z-Dol; manufactured by Ausimont Co., Ltd.) having hydroxyl group at the molecular weight terminal may be used.
[0102] As the extreme-pressure additive, phosphoric acid esters such as trilauryl phosphate, phosphorous acid esters such as trilauryl phosphite, thiophosphorous acid esters such as trilauryl trithiophosphite, sulfur type extreme-pressure agent such as dibenzyl disulfide may be used.
[0103] The above lubricants may be used alone or in combination of two or more. A solution obtained by dissolving the lubricant in organic solvent may be coated on the surface of the protective layer by spin coating method, wire bar coating method, gravure coating method, dip coating method, etc. or the lubricant may be attached on the surface of the protective layer by vacuum deposition method. The amount of coating of the lubricant is preferably in the range of 1 to 30 mg/m 2 , or more preferably in the range of 2 to 20 mg/m 2 .
[0104] To have higher corrosion-resistant property, it is preferable to use a rust-preventive agent simultaneously. As the rust-preventive agent to be used in the present invention, nitrogen-containing heterocyclic compounds such as benzotriazole, benzimidazole, purine, pyrimidine, etc., derivatives prepared by introducing alkyl side-chain to the base nucleus, nitrogen- or sulfur-containing hetero-cyclic compounds and derivatives such as benzothiazole, 2-mercaptobenzothiazole, tetrazaindene cyclic compound, or thiouracil compound may be used. These rust-preventive agents may be mixed with the lubricant and coated on the protective layer. Or, it may coated on the protective layer before the coating of the lubricant, and then, the lubricant may be coated on it. The amount of coating of the rust-preventive agent is preferably in the range of 0.1 to 10 mg/m 2 , or more preferably in the range of 0.5 to 5 mg/m 2 .
[0105] FIG. 3 represents cross-sectional views, each showing another embodiment of the present invention.
[0106] FIG. 3 (A) is a drawing to explain a case where the magnetic recording medium is a flexible disk.
[0107] In a flexible disk 21 , a chromium-containing primer layer 25 A is provided on each of the surfaces of the flexible polymer support member 22 . On each of the chromium-containing primer layers 25 A, a magnetic layer 26 is formed. The magnetic layer 26 comprises a ferromagnetic metal alloy 29 at least containing cobalt, platinum and chromium and a nonmagnetic material 30 . On the magnetic layer 26 , a protective layer 27 is formed which prevents deterioration of the magnetic layer due to oxidation and protects from wearing caused by the contact with the head or the sliding member. On the protective layer 27 , a lubricating layer 28 is arranged for the purpose of improving running durability and corrosion-resistant property. Also, at the center of the disk, engaging means 31 for engaging with the flexible disk drive is arranged.
[0108] In the magnetic recording medium shown in FIG. 3 (B), an undercoating layer 23 is provided on each of the surfaces of the flexible polymer support member. These undercoating layers 23 adjust surface property of the flexible polymer support member 22 and prevent a gas generated from the flexible polymer support member 22 from reaching the chromium-containing primer layer 25 A or the magnetic layer 26 . Further, seed layers 24 are provided to control crystal orientation of the chromium-containing primer layer 25 .
[0109] Compared with the disk shown in FIG. 3 (A), the disk shown in FIG. 3 (B) is provided with the seed layers 24 . These seed layers have effects to adjust crystal orientation of the primer layer. As a result, the ferromagnetic metal formed on the primer layer can have better crystal orientation, and a magnetic layer with better magnetic characteristics can be obtained.
[0110] The flexible disk of the present invention is used in such manner that it is mounted on a synthetic resin cartridge with an access window for the head when it is installed in an equipment.
[0111] FIG. 4 represents cross-sectional views, each showing a magnetic layer of the magnetic recording medium shown in FIG. 3 .
[0112] As shown in FIG. 4 (A), a chromium-containing primer layer 25 A is provided on a nonmagnetic support member, which comprises a flexible polymer support member 22 , and a magnetic layer 26 is formed on the chromium-containing primer layer 25 A. The magnetic layer 26 comprises a ferromagnetic metal alloy 29 containing at least cobalt, platinum and chromium, and a nonmagnetic material 30 . The ferromagnetic metal alloy 29 and the nonmagnetic material 30 appear to be mixed together. However, the ferromagnetic metal alloy 29 shown in the figure is a portion where the content of the ferromagnetic metal alloy is relatively higher compared with the entire composition, and the nonmagnetic material 30 is a portion where the content of the nonmagnetic material is relatively higher compared with the entire composition. The portions where the content of the ferromagnetic metal alloy is higher are positioned with a spacing of 0.01 nm to 10 nm from each other.
[0113] In the present invention, it is desirable that crystal growth occurs by reflecting crystal orientation of the chromium-containing primer layer 25 A, and the magnetic layer 26 is formed in column-like structure as shown in FIG. 4 . By designing in such structure, the portions abundant with the magnetic metal alloy are separated from the portions abundant with the nonmagnetic material in stable manner, and high coercive force can be achieved. The amount of magnetization is increased in the portions abundant with ferromagnetic metal alloy, and this leads to higher output. Further, the portions abundant with the ferromagnetic metal alloy are dispersed evenly, and this contributes to the reduction of noise.
[0114] As the material of the chromium-containing primer layer, for the purpose of controlling the crystal orientation of the magnetic layer, i.e. for the purpose of controlling lattice constant and of improving close adhesion, at least one type is selected from the group of Be, Mg, Al, Si, P, S, Ca, Sc, Ti, V, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Se, Rb, Sr, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sb, Te, Cs, Ba, Hf, Ta, W, Re, Os, Ir, Pt, Tl, Pb, and Bi.
[0115] Among these, it is preferable to use a chromium-containing alloy, which contains at least one type of element selected from a group of Co, Be, Os, Re, Ti, Zn, Ta, Al, Mo, W, V, Fe, Sb, Ir, Ru, Rh, Pt, Pd, Si and Zr. From the viewpoint of control of lattice constant and of improvement of close adhesion, it is preferable to use Ti, Be, Ru, Si, or Zr.
[0116] By the use of these primer layers, the magnetic layer can have better orientation property, and this contributes to the improvement of recording characteristics.
[0117] In the chromium alloy of the primer layer, mixing ratio of chromium with other elements is preferably in the following range: Chromium to other elements=99:1 to 70:30 (atom ratio), or more preferably in the range of 95:5 to 80:20. When the ratio of chromium is higher or lower than the above range, it is difficult to control crystal orientation of the magnetic layer, and magnetic characteristics are decreased.
[0118] The thickness of the primer layer comprising chromium alloy is preferably in the range of 10 nm to 200 nm, or more preferably in the range of 10 nm to 100 nm. If it is thicker than this range, productivity is decreased. Crystal size is increased and this leads to the increase of noise when the recording information is read. On the contrary, if it is thinner, the improvement of the magnetic characteristics due to the effect of the primer layer cannot be attained.
[0119] As the methods to form the chromium-containing primer layer, vacuum film-forming method such as vacuum deposition method, sputtering method, etc. may be used. Above all, the sputtering method is useful in forming ultra-thin film of good quality in easy manner, and it is suitable for the present invention. As the sputtering method, DC sputtering method or RF sputtering method may be used. For the sputtering method, a web sputtering apparatus for continuously forming the film on a continuous film is suitable in case of a flexible disk, which uses a flexible polymer film as a support member. When aluminum substrate or glass substrate is used, a leaf type sputtering apparatus or a passage type sputtering apparatus may be used.
[0120] When the chromium-containing primer layer is formed by sputtering, argon can be used as a sputtering gas, while other type of rare gas may also be used. Also, a slight quantity of oxygen gas may be introduced for the purpose of controlling the lattice constant of the primer layer.
[0121] To form the chromium-containing primer layer by the sputtering method, both chromium target and other element target can be used and co-sputtering method may be adopted, while, for the purpose of precisely controlling the lattice constant and of producing uniform film, it is preferable to use chromium alloy target, which comprises chromium and other element. This alloy target can be prepared by means such as hot press method.
[0122] For the purpose of improving adhesiveness and to improve crystal orientation property between the primer layer and the flexible polymer support member, it is preferable to provide a seed layer. As the seed layer, it is preferable to use Ta, Ta—Si, Ta—Al, Ta—C, Ta—W, Ta—Ti, Ta—N, Ta—Ni, Ta—O, Ta—P, Ni—P, Ni—Al, Ni—C, Ni—Ti, Ni—W, Ni—Si, Ni—N, Ni—O, Ti—W, Ti—C, Ti—N, Ti—Si, Ti—O, Ti—P, Al—Ti, Mg—O, Mg—W, Mg—C, Mg—N, Mg—Ti, Mg—Ni, Mg—Al, Mg—Si, Mg—P, Zn—Si, Zn—Al, Zn—C, Zn—W, Zn—Ti, Zn—N, Zn—Ni, Zn—O, Zn—P, etc. Above all, it is preferable to use Ta, Ta—Si, Ta—C, Ni—P, Ni—Al, Ti—W, Ti—C, Mg—O, Zn—Si, etc. for the purpose of improving the adhesiveness and to have better crystal orientation property.
[0123] To form the seed layer, vacuum film-forming method such as vacuum deposition method, sputtering method, etc. may be used. Above all, the sputtering method is useful in forming ultra-thin film with good quality.
[0124] FIG. 5 represents cross-sectional views, each showing still another embodiment of the present invention.
[0125] FIG. 5 (A) is a drawing to explain a case where the magnetic recording medium is a flexible disk.
[0126] In a flexible disk 21 , a ruthenium-containing primer layer 25 B is arranged on each of the surfaces of a flexible polymer support member 22 , and a magnetic layer 26 is arranged on each of the ruthenium-containing primer layers 25 B. The magnetic layer 26 comprises a ferromagnetic metal alloy 29 containing at least cobalt, platinum and chromium, and a nonmagnetic material 30 . On each of the magnetic layers 26 , a protective layer 27 is formed, which prevents deterioration of the magnetic layer due to oxidation and protects from wearing caused by the contact with the head or the sliding member. Also, a lubricating layer 28 is provided on the protective layer 27 for the purpose of improving running durability and corrosion-resistant property. At the center of the disk, engaging means 31 for engaging with a flexible disk drive is arranged.
[0127] In the magnetic recording medium shown in FIG. 5 (B), an undercoating layer 23 is provided on each of the surfaces of the flexible polymer support member 22 , and the undercoating layer is used to adjust surface property of the flexible polymer support member 22 and to prevent the gas generated from the flexible polymer support member 22 from reaching the ruthenium-containing primer layer 25 B or the magnetic layer 26 . Further, a seed layer 24 is provided, which controls crystal orientation property of the ruthenium-containing primer layer 25 B.
[0128] Compared with the disk shown in FIG. 5 (A), the disk shown in FIG. 5 (B) has the seed layer. This is useful in adjusting crystal orientation property of the ruthenium-containing primer layer. This is helpful in attaining the better crystal orientation property of the ferromagnetic metal formed on the primer layer, and a magnetic layer with the better magnetic characteristics can be obtained.
[0129] Also, the flexible disk of the present invention is used by mounting in a synthetic resin cartridge with an access window for the head when it is installed in an equipment.
[0130] When ruthenium is used, crystal orientation can be easily attained in film formation at room temperature. By using the ruthenium primer layer, crystal orientation of the magnetic layer can be controlled even when the film is formed at room temperature. This is reported by Ohmori et al. in the Journal of the Japan Society of Applied Magnetic Science Vol. 25, pp. 607-610 (2001). In fact, however, there is difference between lattice constant of ruthenium and that of cobalt, and it is not optimal from the viewpoint of the improvement of recording characteristics of the magnetic layer. Also, ruthenium has very high film stress and it has poor adhesiveness with the substrate. For this reason, it is necessary to provide one more adhesive layer under the primer layer. Further, it was found that, when the flexible polymer support member was used, the substrate was deformed due to film stress.
[0131] Under such circumstances, there have been strong demands on the formation of a primer layer, which has lower film stress and makes it possible to control crystal orientation of the magnetic layer when the film is formed at room temperature and to improve recording characteristics of the magnetic layer. The ruthenium-containing primer layer of the present invention contains other elements together with ruthenium, and it is possible to improve recording characteristics by the control of the crystal orientation of the magnetic layer even when the film is formed at room temperature. Also, it was found that film stress was lower than ruthenium.
[0132] By the use of the ruthenium-containing primer layer and the ferromagnetic metal thin film, there is no need any more to heat the substrate as in the past, and it is possible to attain good magnetic characteristics even when substrate temperature is at room temperature. In this respect, not only when glass substrate or aluminum substrate is used, but also when the support member is made of polymer film, no thermal damage occurs. Thus, it is possible to provide a flat flexible disk without possibility of deformation.
[0133] The magnetic layer may be the so-called vertical magnetic recording film having an axis of easy magnetization in vertical direction with respect to the disk surface, or it may be an in-plane magnetic recording film now widely used in hard disk. The direction of the axis of easy magnetization can be controlled by the material and crystal structure of the ruthenium-containing primer layer and by composition and film-forming condition of the magnetic film.
[0134] The magnetic layer used in the magnetic recording medium of the present invention is a magnetic layer, which comprises a ferromagnetic metal alloy containing cobalt, platinum and chromium, and a nonmagnetic material.
[0135] FIG. 6 represents cross-sectional views, each showing a magnetic layer of the magnetic recording medium shown in FIG. 5 .
[0136] In FIG. 6 (A), a magnetic layer 26 is formed on a ruthenium-containing primer layer 25 B on a nonmagnetic support member, which comprises a flexible polymer support member 22 .
[0137] The magnetic layer 26 comprises a ferromagnetic metal alloy 29 containing at least cobalt, platinum and chromium, and a nonmagnetic material 30 . The ferromagnetic metal alloy 29 and the nonmagnetic material 30 appear to be mixed together. However, the ferromagnetic metal alloy 29 as shown in the figure represents portions where the content of the ferromagnetic metal alloy is higher compared with the entire composition. The nonmagnetic material 30 represents portions where the content of the nonmagnetic material is higher compared with the entire composition.
[0138] Also, the portions where the content of the ferromagnetic metal alloy is higher are positioned with a spacing of 0.01 nm to 10 nm from each other.
[0139] It is desirable that crystal growth occurs by reflecting the crystal orientation of the ruthenium-containing primer layer 25 B, and the magnetic layer 26 is formed in column-like structure as shown in FIG. 6 (B). By designing in such structure, portions abundant with the ferromagnetic metal alloy and the portions abundant with the nonmagnetic material can be separated from each other in stable manner, and high coercive force can be maintained. Because the amount of magnetization is increased in the portions abundant with the ferromagnetic metal alloy, high output can be achieved. Moreover, the portions abundant with the ferromagnetic metal alloy are dispersed evenly and the noise is decreased.
[0140] In the following, description will be given on a method to prepare the magnetic recording medium using the flexible polymer support member.
[0141] FIG. 7 is a schematical drawing to explain a method to form a magnetic layer on a flexible polymer support member.
[0142] A film-forming apparatus 1 comprises a vacuum chamber 2 . A flexible polymer support member 4 unwound from an unwinding roll 3 is adjusted of its tension by tension adjusting rolls 5 A and 5 B, and it is sent to a film-forming chamber 6 .
[0143] In the film-forming chamber 6 , argon is supplied at a predetermined flow rate from a sputtering gas supply pipe 7 A- 7 D under reduced pressure set by a vacuum pump. The flexible polymer support member 4 is wound on a film-forming roll 8 A in the film-forming chamber 6 . From a target TA of a primer layer sputtering apparatus 9 A, atoms for forming the primer layer are ejected and a film is formed on the flexible polymer support member.
[0144] Next, on the film-forming roll 8 A, atoms for forming the magnetic layer are ejected from a target TB, which is mounted on a magnetic layer sputtering apparatus 9 B and in which the ferromagnetic metal alloy and nonmagnetic oxide are uniformly dispersed. The atoms are ejected to the primer layer, and a magnetic layer is formed on the primer layer.
[0145] Next, the surface with the magnetic layer formed on it is wound on the film-forming roll 8 B and, while moving, atoms for forming the primer layer are ejected from a target TC of a primer layer sputtering apparatus 9 C, and a film is formed on a surface opposite to the surface of the flexible polymer support member where the magnetic layer has been formed. Further, on a film-forming roll 8 B, atoms for forming the magnetic layer are ejected from a target TD, which is mounted on a magnetic layer sputtering apparatus 9 D and in which the ferromagnetic metal alloy and the nonmagnetic oxides are uniformly dispersed, and a magnetic layer is formed on the primer layer.
[0146] By the process as described above, the magnetic layers are formed on both surfaces of the flexible polymer support member, and these magnetic layers are wound up on a winding roll 10 .
[0147] In the above, description has been given on a method to form magnetic layers on both surfaces of the flexible polymer support member, while it is also possible to form the magnetic layer only on one surface by similar method.
[0148] After the magnetic layers have been formed, a protective layer comprising the diamond-like carbon is formed on the magnetic layer by CVD method.
[0149] FIG. 8 is a schematical drawing to explain an example of a CVD apparatus, which uses high frequency plasma and is applicable in the present invention.
[0150] A flexible polymer support member 42 with the magnetic layer 41 formed on it is unwound from a roll 43 . Bias voltage is supplied from a bias power source 45 via a pass roller 44 to the magnetic layer 41 , and the support member is sent as it is wound up on a film-forming roll 46 .
[0151] On the other hand, a raw material gas 47 containing hydrocarbon, nitrogen, rare gas, etc. is sent, and by the plasma generated by the voltage applied from a high frequency power source 48 , a carbon protective film 49 containing nitrogen and rare gas is formed on a metal thin film on the film-forming roll 46 , and the carbon protective film is wound up on a winding roll 50 . Through purification of the surface of the magnetic film by flow processing using rare gas or hydrogen gas prior to the preparation of the carbon protective film, higher adhesion can be maintained. By forming a silicon intermediate layer on the surface of the magnetic layer, the higher adhesion can be obtained.
[0152] Description will be given below on Examples and Comparative examples to explain the present invention.
Preparation of the Magnetic Tape
EXAMPLE 1-1
[0153] On a polyethylene terephthalate film of 6.3 μm in thickness and with surface roughness Ra=1.2 nm, an undercoating solution containing 3-glycidoxypropyl-trimethoxysilane, phenyltriethoxysilane, hydrochloric acid, aluminum acetylacetonate, and ethanol was coated by gravure coating method. Then, this was dried and hardened at 100° C., and an undercoating layer comprising silicone resin of 0.2 μm in thickness was prepared.
[0154] On the undercoating layer thus obtained, a coating solution containing silica sol of 25 nm in particle size and the undercoating solution were coated by gravure coating method. Projections of 15 nm in height were formed on the undercoating layer in density of 10 projection/μm 2 , and this was regarded as an original material for the magnetic tape.
[0155] Next, this original material for the magnetic tape was mounted on a web sputtering apparatus shown in FIG. 7 , and this was transported while the film was closely fitted on a water-cooled film-forming roll. On the undercoating layer, a primer layer comprising Cr:Ti=80:20 (atom ratio) was formed in thickness of 30 nm by DC magnetron sputtering method. Next, a magnetic layer with composition of CoPtCr alloy (Co:Pt:Cr=70:20:10 (atom ratio): SiO 2 =88:12 (atom ratio) was formed in thickness of 25 nm.
[0156] Next, the original material with the magnetic layer formed on it was mounted on a web type CVD apparatus as shown in FIG. 8 . By RF plasma CVD method using ethylene gas, nitrogen gas and argon gas as reaction gas, a nitrogen-added diamond-like carbon (DLC) protective film with composition of C:H:N=62:29:7 (mol ratio) was formed in thickness of 10 nm. In this case, bias voltage of −400 V was applied on the magnetic layer.
[0157] Next, on a surface of the flexible polymer support member opposite to the surface where the magnetic layer was formed, carbon black, calcium carbonate, stearic acid, nitrocellulose, polyurethane, and isocyanate hardening agent were dissolved and dispersed in methyl ethyl ketone to prepare a back-coating solution. Then, the back-coating solution was coated by wire bar coating method. This was dried at 100° C. and a back-coating layer of 0.5 μm in thickness was prepared.
[0158] Further, perfluoropolyether lubricant (Fomblin Z-Dol; manufactured by Ausimont Co., Ltd.) having hydroxyl group at molecular terminal was dissolved in a fluorine type solvent (HFE-7200; Manufactured by Sumitomo 3M Co., Ltd.), and this solution was coated on the surface of the protective layer by gravure coating method, and a lubricating layer of 1 nm in thickness was prepared.
[0159] The original material for the magnetic tape thus prepared was cut off to have a width of 8 mm, and the surface was polished. Then, this was mounted on a cartridge for 8-mm video cassette, and a magnetic tape was prepared.
[0160] On the magnetic tape, characteristics were evaluated by the evaluation method 1 as given below. The results are shown in Table 1.
COMPARATIVE EXAMPLE 1-2
[0161] A magnetic tape was prepared by the same procedure as in Example 1-1 except that the composition of the magnetic layer was set to Co:Pt:Cr=70:20:10. This was evaluated by the same procedure as in Example 1-1. The results are shown in Table 1.
COMPARATIVE EXAMPLE 1-2
[0162] A magnetic tape was prepared by the same procedure as in Example 1-1 except that temperature of the film-forming roll during the formation of the primer layer and the magnetic layer was set to 150° C. This was evaluated by the same procedure as in Example 1-1. The results are shown in Table 1.
Evaluation Method 1
[heading-0163] 1. Magnetic Characteristics
[0164] Coercive force Hc was determined using a specimen vibration type magnetometer (VSM), and this was defined as magnetic characteristics.
[heading-0165] 2. Cupping Amount
[0166] The magnetic tape was cut off to have a length of 100 mm. This was placed on a smooth glass plate, and tape width was measured. Deformation in width direction of the tape was defined as cupping amount.
[heading-0167] 3. C/N
[0168] Using an MR head with reproduction track width of 2.2 μm and reproduction gap of 0.26 μm, recording and reproduction were performed with linear recording density, of 130 kFCI, and reproduction signal/noise (C/N) ratio was determined. In this case, relative speed of tape/head was set to 10 m/sec., and head weighting was set to 29.4 mN (3 gf).
[heading-0169] 4. Durability
[0170] Still reproduction was performed using a 8-mm video tape recorder. Still reproduction time up to the moment when the output reached the initial value −3dB was defined as durability time. Measurement was performed under the conditions of 23° C. and 10 relative humidity. The test was carried out up to 24 hours at maximum.
TABLE 1 Hc Cupping C/N Durability time (kA/m) (mm) (dB) (h) Example 1-1 199 7.9 0 >24 Comparative 119 7.9 −5.9 >24 example 1-1 Comparative 183 6.8 Not 0.1 example 1-2 measurable
[0171] From the results shown in the above table, it is evident that the magnetic tape of the present invention has good quality in both recording characteristics and durability. On the other hand, the magnetic tape of Comparative example 1-1, which does not contain nonmagnetic oxide in the magnetic layer exhibited lower coercive force (Hc) and poor recording characteristics. Further, in Comparative example 1-2 prepared at high film-forming temperature for the primer layer and the magnetic layer, the coercive force was improved, but the film of the flexible polymer support member was deformed by heat, and durability was extremely decreased. When the surface of the tape was examined under microscope, small cracks were observed on the magnetic layer.
Preparation of flexible Disk
EXAMPLE 2-1
[0172] On a polyethylene terephthalate film of 6.3 μm in thickness and with surface roughness Ra=1.4 nm, an undercoating solution containing 3-glycidoxypropyl-trimethoxysilane, phenyltriethoxysilane, hydrochloric acid, aluminum acetylacetonate, and ethanol was coated by gravure coating method. Then, this was dried and hardened at 100° C., and an undercoating layer comprising silicone resin of 1.0 μm in thickness was prepared.
[0173] On the undercoating layer thus obtained, a coating solution containing silica sol of 25 nm in particle size and the undercoating solution were coated by gravure coating method. Projections of 15 nm in height were formed on the undercoating layer in density of 10 projection/μm 2 . This undercoating layer was formed on each of both surfaces of the flexible polymer support member film. The flexible polymer support member film thus obtained was regarded as the original film and was mounted on a sputtering apparatus.
[0174] Next, this original material for the magnetic tape was mounted on a web sputtering apparatus shown in FIG. 7 , and this was transported while the film was closely fitted on a water-cooled film-forming roll. On the undercoating layer, a primer layer comprising Cr:Ti=80:20 (atom ratio) was formed in thickness of 30 nm by DC magnetron sputtering method. Next, a magnetic layer with composition of CoPtCr alloy (Co:Pt:Cr=70:20:10 (atom ratio): SiO 2 =88:12 (atom ratio) was formed in thickness of 25 nm.
[0175] The primer layer and the magnetic layer were formed on both surfaces of the film. Next, the original material with the magnetic layer formed on it was mounted on a web type CVD apparatus as shown in FIG. 8 . By RF plasma CVD method using ethylene gas, nitrogen gas and argon gas as reaction gas, a nitrogen-added diamond-like carbon (DLC) protective film with composition of C:H:N=62:29:7 (mol ratio) was formed in thickness of 10 nm. In this case, bias voltage of −400 V was applied on the magnetic layer. The protective layer was also formed each on both surfaces of the film.
[0176] Further, perfluoropolyether lubricant (Fomblin Z-Dol; manufactured by Montefluos Co., Ltd.) having hydroxyl group at molecular terminal was dissolved in a fluorine type solvent (HFE-7200; Manufactured by Sumitomo 3M Co., Ltd.), and this solution was coated on the surface of the protective layer by gravure coating method, and a lubricating layer of 1 nm in thickness was prepared.
[0177] From the original material thus obtained, a piece in form of a disk with diameter of 94 mm was punched out. After this was polished, it was engaged in a synthetic resin cartridge for flexible disk (for Zip 100; manufactured by Fuji Photo Film Co., Ltd.), and a flexible disk was prepared.
[0178] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 2.
EXAMPLE 2-2
[0179] From the original material with the undercoating layer formed on it in Example 2-1, a disk-like sheet of 130 mm in diameter was punched out, and this was fixed on a circular ring. Using a batch type sputtering apparatus, a primer layer and a magnetic layer with the same compositions as in Example 2-1 were formed on both surfaces of the sheet, and a protective film was also formed using CVD apparatus. On this sheet, the same lubricating layer as in Example 2-1 was formed by dip coating method. Next, a piece in form of a disk of 94 mm in diameter was punched out from this sheet. After polishing with tape, this was engaged on a synthetic resin cartridge for flexible disk (for zip 100; Fuji Photo Film Co., Ltd.), and a flexible disk was prepared.
[0180] On the flexible disk thus prepared, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 2.
REFERENCE EXAMPLE 2-1
[0181] A hard disk was prepared by the same procedure as in Example 2-2 except that a glass substrate of 94 mm in diameter with the mirror-polished surface was used as a substrate. However, the undercoating layer was not formed, and it was not engaged on a cartridge.
[0182] On the hard disk thus obtained, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 2.
COMPARATIVE EXAMPLE 2-1
[0183] A flexible disk was prepared by the same procedure as in Example 2-1 except that composition of the magnetic layer was set to Co:Pt:Cr=70:20:10 (atom ratio). On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 2.
COMPARATIVE EXAMPLE 2-2
[0184] A flexible disk was prepared by the same procedure as in Comparative example 2-1 except that film-forming temperature during formation of the primer layer and the magnetic layer was set to 150° C.
[0185] On the flexible disk thus prepared, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 2.
Evaluation Method 2
[heading-0186] 1. Magnetic Characteristics
[0187] Coercive force (Hc) was determined using a specimen vibration type magnetometer (VSM), and this was defined as magnetic characteristics.
[heading-0188] 2. Surface Deviation
[0189] The flexible disk and the hard disk were rotated at 3000 rpm, and surface deviation at a position of 35 mm in radial direction from the center was measured using a laser displacement gauge.
[heading-0190] 3. C/N
[0191] Using an MR head with reproduction width of 2.2 μm and reproduction gap of 0.26 μm, recording and reproduction were performed with linear recording density of 130 kFCI, and reproduction signal/noise (C/N) was measured. In this case, number of revolutions was set to 3000 rpm, and the head was set at 35 mm in radial direction. Head weighting was set to 29.4 mN (3 gf).
[heading-0192] 4. Modulation
[0193] Reproduction output at the time of C/N measurement was determined for one turn of the disk. The ratio of the minimum value of the output to the maximum value was expressed in %.
[heading-0194] 5. Durability
[0195] Except the hard disk, the flexible disk was engaged on a drive for flexible disk (Drive for Zip 100; manufactured by Fuji Photo Film Co., Ltd.), and this was run while recording and reproduction were carried out repeatedly. Running was stopped at the moment when the output value reached the initial value −3dB, and this was defined as durability type. The conditions for the measurement was 23° C. and 50% relative humidity, and the test was carried out up to 300 hours at maximum.
TABLE 2 Surface Durability HC deviation C/N Modulation time (kA/m) (μm) (dB) (%) (h) Example 2-1 199 25 0 95 >300 Example 2-2 207 30 +0.5 92 >300 Reference 207 10 −1.2 97 — example 2-1 Comparative 119 30 −6.2 94 >300 example 2-1 Comparative 183 75 −2.5 78 13 example 2-2
[0196] As it is evident from the results of Examples and Comparative examples shown in the above table, the flexible disk of the present invention has good quality in both recording characteristics and durability. On the other hand, in Reference example 2-1 where glass substrate was used as substrate, the value of C/N was somewhat lower compared with the flexible disk of Example 2-1 prepared by the same procedure. This is because the output was relatively lower and because floating amount of the head was higher in the hard disk than in the flexible disk.
[0197] In Comparative example 2-1 where nonmagnetic oxide (SiO 2 ) was not used in the magnetic layer, coercive force was lower and recording characteristics were poor. Further, in Comparative example 2-2 where film-forming temperature for formation of the primer layer and the magnetic layer was higher, coercive force was improved, but the flexible polymer support member film was deformed by heat, and surface deviation and durability were aggravated.
EXAMPLE 3-1
[0198] On a polyethylene terephthalate film of 6.3 μm in thickness and with surface roughness Ra=1.4 nm, an undercoating solution containing 3-glycidoxypropyl-trimethoxysilane, phenyltriethoxysilane, hydrochloric acid, aluminum acetylacetonate, and ethanol was coated by gravure coating method. Then, this was dried and hardened at 100° C., and an undercoating layer comprising silicone resin of 1.0 μm in thickness was prepared.
[0199] On the undercoating layer thus obtained, a coating solution containing silica sol of 25 nm in particle size and the undercoating solution were coated by gravure coating method. Projections of 15 nm in height were formed on the undercoating layer in density of 10 projections/μm 2 . Also, the undercoating layer was formed on both surfaces of the flexible polymer support member film. The flexible polymer support member thus obtained was used as the original material, and this was mounted on a sputtering apparatus.
[0200] Next, this original material for the magnetic tape was mounted on a web sputtering apparatus shown in FIG. 7 , and this was transported while the film was closely fitted on a water-cooled film-forming roll. On the undercoating layer, a primer layer comprising Cr:Ti=80:20 (atom ratio) was formed in thickness of 30 nm by DC magnetron sputtering method. Next, a magnetic layer with composition of CoPtCr alloy (Co:Pt:Cr=70:20:10 (atom ratio):SiO 2 =88:12 (atom ratio) was formed in thickness of 25 nm.
[0201] The primer layer and the magnetic layer were formed each on both surfaces of the film. Next, the original material with the magnetic layer formed on it was mounted on a web type CVD apparatus as shown in FIG. 8 . By RF plasma CVD method using ethylene gas, nitrogen gas and argon gas as reaction gas, a nitrogen-added diamond-like carbon (DLC) protective film with composition of C:H:N=62:29:7 (mol ratio) was formed in thickness of 10 nm. In this case, bias voltage of −400 V was applied on the magnetic layer. The protective layer was also formed on both surfaces of the film.
[0202] Further, perfluoropolyether lubricant (Fomblin Z-Dol; manufactured by Ausimont Co., Ltd.) having hydroxyl group at molecular terminal was dissolved in a fluorine type solvent (HFE-7200; Manufactured by Sumitomo 3M Co., Ltd.), and this solution was coated on the surface of the protective layer by gravure coating method, and a lubricating layer of 1 nm in thickness was prepared.
[0203] From the original material thus obtained, a piece in form of a disk with diameter of 94 mm was punched out. After this was polished, it was engaged in a synthetic resin cartridge for flexible disk (for Zip 100; manufactured by Fuji Photo Film Co., Ltd.), and a flexible disk was prepared.
[0204] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 4.
EXAMPLE 3-2
[0205] From the original material with the undercoating layer formed on it in Example 3-1, a disk-like sheet of 130 mm in diameter was punched out, and this was fixed on a circular ring. Using a batch type sputtering apparatus, a primer layer and a magnetic layer with the same compositions as in Example 3-1 were formed on both surfaces of the sheet, and a protective film was also formed using CVD apparatus. On this sheet, the same lubricating layer as in Example 2-1 was formed by dip coating method. Next, a piece in form of a disk of 94 mm in diameter was punched out from this sheet. After polishing with tape, this was engaged on a synthetic resin cartridge for flexible disk (for zip 100; Fuji Photo Film Co., Ltd.), and a flexible disk was prepared.
[0206] On the flexible disk thus prepared, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 4.
EXAMPLES 3-3 TO 3-25
[0207] A flexible disk was prepared by the same procedure as in Example 3-1 except that composition and thickness of the primer layer were set to the values shown in Table 3.
[0208] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 4.
TABLE 3 Primer layer Alloy element 1 Alloy element 2 Film thickness Example (atom ratio) (atom ratio) (nm) Example 3-3 Cr (80) Ti (20) 30 Example 3-4 Cr (80) Ti (20) 40 Example 3-5 Cr (90) Ti (10) 60 Example 3-6 Cr (95) Ti (5) 60 Example 3-7 Cr (80) Be (20) 60 Example 3-8 Cr (80) Si (20) 60 Example 3-9 Cr (80) Zr (20) 60 Example 3-10 Cr (80) Co (20) 60 Example 3-11 Cr (80) Os (20) 60 Example 3-12 Cr (80) Re (20) 60 Example 3-13 Cr (80) Ru (20) 60 Example 3-14 Cr (80) Zn (20) 60 Example 3-15 Cr (80) Ta (20) 60 Example 3-16 Cr (80) Al (20) 60 Example 3-17 Cr (80) Mo (20) 60 Example 3-18 Cr (80) W (20) 60 Example 3-19 Cr (80) V (20) 60 Example 3-20 Cr (80) Fe (20) 60 Example 3-21 Cr (80) Sb (20) 60 Example 3-22 Cr (80) Ir (20) 60 Example 3-23 Cr (80) Rh (20) 60 Example 3-24 Cr (80) Pt (20) 60 Example 3-25 Cr (80) Pd (20) 60
EXAMPLE 3-26
[0209] A flexible disk was prepared by the same procedure as in Example 3-1 except that a Ta seed layer was introduced between the undercoating layer and the Cr—Ti primer layer.
[0210] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 4.
EXAMPLE 3-27
[0211] A glass substrate of 94 mm in diameter and having mirror-polished surface was used as substrate. A magnetic recording medium having a magnetic layer, a protective layer and a lubricating layer as in Example 3-1 was prepared without forming an undercoating layer.
[0212] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 4.
COMPARATIVE EXAMPLE 3-1
[0213] A flexible disk was prepared by the same procedure as in Example 3-1 except that composition of the magnetic layer was set to Co:Pt:Cr=70:20:10 (atom ratio).
[0214] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 4.
COMPARATIVE EXAMPLE 3-2
[0215] A flexible disk was prepared by the same procedure as in Example 3-1 except that chromium was used in the primer layer.
[0216] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 4.
COMPARATIVE EXAMPLE 3-3
[0217] A flexible disk was prepared by the same procedure as in Comparative example 3-2 except that a tantalum seed layer was formed between the undercoating layer and the chromium-containing primer layer.
[0218] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 4.
TABLE 4 Surface Durability Hc deviation C/N Modulation time (kA/m) (μm) (dB) (%) (h) Example 3-1 231 25 0 95 >300 Example 3-2 239 30 +1.0 92 >300 Example 3-3 199 30 −3.0 94 >300 Example 3-4 215 35 −1.4 92 >300 Example 3-5 191 25 −3.4 96 >300 Example 3-6 175 40 −4.2 91 >300 Example 3-7 227 20 −0.5 96 >300 Example 3-8 211 15 −1.0 97 >300 Example 3-9 208 17 −1.4 96 >300 Example 3-10 238 35 −0.1 90 >300 Example 3-11 223 30 −0.3 94 >300 Example 3-12 227 35 −0.2 93 >300 Example 3-13 247 35 +0.2 91 >300 Example 3-14 231 30 −0.1 92 >300 Example 3-15 227 35 −0.5 92 >300 Example 3-16 215 40 −1.4 90 >300 Example 3-17 231 30 −0.2 93 >300 Example 3-18 219 40 −1.0 90 >300 Example 3-19 215 40 −1.2 91 >300 Example 3-20 223 40 −0.6 90 >300 Example 3-21 221 30 −0.2 94 >300 Example 3-22 225 35 −0.1 93 >300 Example 3-23 207 35 −0.9 92 >300 Example 3-24 239 40 −0.2 93 >300 Example 3-25 223 30 −0.4 92 >300 Example 3-26 247 20 +1.2 97 >300 Example 3-27 231 10 −1.0 98 — Comparative 143 30 −8.2 90 >300 example 3-1 Comparative 167 30 −6.4 92 >300 example 3-2 Comparative 187 20 −3.4 90 >300 example 3-3
[0219] As shown in Examples 3-1 to 3-25 in the above table, it is evident that the flexible disk of the present invention has good quality in both recording characteristics and durability. Further, in Example 3-26 with the Ta seed layer under the primer layer, magnetostatic characteristics are improved due to better adhesion, and also, C/N characteristics are improved.
[0220] On the other hand, in Example 3-27 where glass substrate was used as substrate, the value of C/N was somewhat lower compared with the flexible disk of Example 3-1, which was prepared by the same procedure. This was because the output was relatively lower and because floating amount of the head was higher in the hard disk than in the flexible disk.
[0221] In Comparative example 3-1 where nonmagnetic material (SiO 2 ) was not used in the magnetic layer, coercive force was lower and recording characteristics were poor. Further, in Comparative example 3-2 using Cr-containing primer layer and in Comparative example 3-3 using both Cr-containing primer layer and Ta seed layer, coercive force was somewhat high, but it was not possible to attain sufficient recording characteristics.
EXAMPLE 4-1
[0222] On a polyethylene terephthalate film of 6.3 μm in thickness and with surface roughness Ra=1.4 nm, an undercoating solution containing 3-glycidoxypropyl-trimethoxysilane, phenyltriethoxysilane, hydrochloric acid, aluminum acetylacetonate, and ethanol was coated by gravure coating method. Then, this was dried and hardened at 100° C., and an undercoating layer comprising silicone resin of 1.0 μm in thickness was prepared.
[0223] On the undercoating layer thus obtained, a coating solution containing silica sol of 25 nm in particle size and the undercoating solution were coated by gravure coating method. Projections of 15 nm in height were formed on the undercoating layer in density of 10 projections/μm 2 . Also, the undercoating layer was formed on both surfaces of the flexible polymer support member film. The flexible polymer support member film was used an original material, and this was mounted on a sputtering apparatus.
[0224] Next, this original material for the magnetic tape was mounted on a web sputtering apparatus shown in FIG. 7 , and this was transported while the film was closely fitted on a water-cooled film-forming roll. On the undercoating layer, a primer layer comprising Ru:Cr=90:10 (atom ratio) was formed in thickness of 40 nm by DC magnetron sputtering method. Next, a magnetic layer with composition of CoPtCr alloy (Co:Pt:Cr=70:20:10 (atom ratio): SiO 2 =88:12 (atom ratio) was formed in thickness of 25 nm.
[0225] The primer layer and the magnetic layer were formed on both surfaces of the film. Next, the original material with the magnetic layer formed on it was mounted on a web type CVD apparatus as shown in FIG. 8 . By RF plasma CVD method using ethylene gas, nitrogen gas and argon gas as reaction gas, a nitrogen-added diamond-like carbon (DLC) protective film with composition of C:H:N=62:29:7 (mol ratio) was formed in thickness of 10 nm. In this case, bias voltage of −400 V was applied on the magnetic layer. The protective film was also formed on both surfaces of the film.
[0226] Further, perfluoropolyether lubricant (Fomblin Z-Dol; manufactured by Ausimont Co., Ltd.) having hydroxyl group at molecular terminal was dissolved in a fluorine type solvent (HFE-7200; Manufactured by Sumitomo 3M Co., Ltd.), and this solution was coated on the surface of the protective layer by gravure coating method, and a lubricating layer of 1 nm in thickness was prepared.
[0227] From the original material thus obtained, a piece in form of a disk with diameter of 94 mm was punched out. After this was polished, it was engaged in a synthetic resin cartridge for flexible disk (for Zip 100; manufactured by Fuji Photo Film Co., Ltd.), and a flexible disk was prepared.
[0228] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 6.
EXAMPLE 4-2
[0229] From the original material with the undercoating layer formed on it in Example 4-1, a disk-like sheet of 130 mm in diameter was punched out, and this was fixed on a circular ring. Using a batch type sputtering apparatus, a primer layer and a magnetic layer with the same compositions as in Example 4-1 were formed on both surfaces of the sheet, and a protective film was also formed using CVD apparatus. On this sheet, the same lubricating layer as in Example 2-1 was formed by dip coating method. Next, a piece in form of a disk of 94 mm in diameter was punched out from this sheet. After polishing with tape, this was engaged on a synthetic resin cartridge for flexible disk (for zip 100; Fuji Photo Film Co., Ltd.), and a flexible disk was prepared.
[0230] On the flexible disk thus prepared, characteristics were evaluated by the evaluation method 2 as given below. The results are shown in Table 6.
EXAMPLES 4-3 TO 4-25
[0231] A flexible disk was prepared by the same procedure as in Example 4-1 except that composition and thickness of the primer layer were set to the values shown in Table 5.
[0232] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 6.
TABLE 5 Primer layer Alloy element 1 Alloy element 2 Film thickness Example (atom ratio) (atom ratio) (nm) Example 4-3 Ru (90) Cr (10) 30 Example 4-4 Ru (90) Cr (10) 60 Example 4-5 Ru (80) Cr (20) 40 Example 4-6 Ru (95) Cr (5) 40 Example 4-7 Ru (90) Be (10) 40 Example 4-8 Ru (90) Si (10) 40 Example 4-9 Ru (90) Zr (10) 40 Example 4-10 Ru (90) Co (10) 40 Example 4-11 Ru (90) Os (10) 40 Example 4-12 Ru (90) Re (10) 40 Example 4-13 Ru (90) Ti (10) 40 Example 4-14 Ru (90) Zn (10) 40 Example 4-15 Ru (90) Ta (10) 40 Example 4-16 Ru (90) Al (10) 40 Example 4-17 Ru (90) Mo (10) 40 Example 4-18 Ru (90) W (10) 40 Example 4-19 Ru (90) Fe (10) 40 Example 4-20 Ru (90) Sb (10) 40 Example 4-21 Ru (90) Ir (10) 40 Example 4-22 Ru (90) Rh (10) 40 Example 4-23 Ru (90) Pt (10) 40 Example 4-24 Ru (90) Pd (10) 40
EXAMPLE 4-25
[0233] A glass substrate of 94 mm in diameter and having mirror-polished surface was used as substrate. A magnetic recording medium having a magnetic layer, a protective layer and a lubricating layer as in Example 4-1 was prepared without forming an undercoating layer.
[0234] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 6.
COMPARATIVE EXAMPLE 4-1
[0235] A flexible disk was prepared by the same procedure as in Example 4-1 except that composition of the magnetic layer was set to Co:Pt:Cr=70:20:10 (atom ratio).
[0236] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 6.
COMPARATIVE EXAMPLE 4-2
[0237] A flexible disk was prepared by the same procedure as in Example 4-1 except that ruthenium was used in the primer layer.
[0238] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 6.
COMPARATIVE EXAMPLE 4-3
[0239] A flexible disk was prepared by the same procedure as in Comparative example 4-2 except that a Ta seed layer was formed between the undercoating layer and the ruthenium-containing primer layer.
[0240] On the flexible disk thus obtained, characteristics were evaluated by the evaluation method 2 as given above. The results are shown in Table 6.
TABLE 6 Surface Durability HC deviation C/N Modulation time (kA/m) (μm) (dB) (%) (h) Example 4-1 263 25 0 95 >300 Example 4-2 271 30 +1.0 92 >300 Example 4-3 239 30 −1.0 94 >300 Example 4-4 247 35 −1.4 92 >300 Example 4-5 231 25 −1.2 96 >300 Example 4-6 263 40 −0.8 91 >300 Example 4-7 247 20 0 96 >300 Example 4-8 239 18 0 97 >300 Example 4-9 243 25 −0.2 96 >300 Example 4-10 279 35 0 90 >300 Example 4-11 263 30 −0.2 94 >300 Example 4-12 267 35 −0.2 93 >300 Example 4-13 256 30 −0.6 90 >300 Example 4-14 251 30 −0.6 92 >300 Example 4-15 247 35 −0.8 92 >300 Example 4-16 231 40 −1.4 90 >300 Example 4-17 255 35 0 93 >300 Example 4-18 247 40 −1.0 90 >300 Example 4-19 271 40 −0.6 90 >300 Example 4-20 253 30 −0.2 94 >300 Example 4-21 259 35 −0.2 93 >300 Example 4-22 255 35 −0.2 92 >300 Example 4-23 271 40 −0.2 93 >300 Example 4-24 247 30 −0.4 92 >300 Example 4-25 247 10 −1.0 98 — Comparative 143 30 −6.2 94 >300 example 4-1 Comparative 191 82 −8.4 73 12 example 4-2 Comparative 255 60 −1.0 85 220 example 4-3
[0241] As shown in Examples 4-1 to 4-25 and in Comparative examples 4-1 and 4-3 in the above table, it is evident that the flexible disk of the present invention has good quality in both recording characteristics and durability. On the other hand, in Example 4-25 using glass substrate as substrate, the value of C/N was somewhat lower compared with the flexible disk of Example 4-1 prepared by the same procedure. This is because the output was relatively lower and because floating amount of the head was higher in the hard disk than in the flexible disk. Also, in Comparative example 4-1 where nonmagnetic material (SiO 2 ) was not used in the magnetic layer, coercive force was lower and recording characteristics were poor. In Comparative example 4-2 using the ruthenium-containing primer layer, coercive force was somewhat high, but the support member film was deformed due to film stress. Also, C/N characteristics were decreased with the increase of surface deviation. In Comparative example 4-3 with a TiW seed layer under the primer layer, the increase of surface deviation could not be prevented due to the influence of film stress caused by the ruthenium-containing primer layer, and C/N characteristics were somewhat lower.
[0242] In the magnetic recording medium of the present invention, a magnetic layer comprising a cobalt-containing ferromagnetic metal alloy and a nonmagnetic oxide is formed on a flexible polymer support member. As a result, a magnetic layer with excellent characteristics can be formed on the flexible polymer support member at the temperature as low as room temperature. Thus, it is possible to provide a magnetic tape and a flexible disk, which are suitable for high-density recording. | A magnetic recording medium, which contains a chromium-containing primer layer and a magnetic layer at least on one surface of a nonmagnetic support member, the chromium-containing primer layer contains chromium and at least one type of element selected from a group of cobalt, beryllium, osmium, rhenium, titanium, zinc, tantalum, aluminum, molybdenum, tungsten, vanadium, iron, antimony, iridium, ruthenium, rhodium, platinum, palladium, silicon, and zirconium, and the magnetic layer contains a ferromagnetic metal alloy containing at least cobalt, platinum and chromium, and a nonmagnetic material. | 6 |
RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 09/104,481, filed Jun. 25, 1998 now U.S. Pat. No. 6,248,183, which is based on provisional application No. 60/051,100, filed Jun. 27, 1997.
BACKGROUND
The present invention relates to conversion coating compounds and processes for applying conversion coating to aluminum and aluminum alloys. In particular, the conversion coating compounds disclosed herein enable non-chromate coatings having self-healing properties.
Aluminum, and its alloys, are a common material used in a variety of applications due to their specific strength as compared to other alloys. Unfortunately, numerous aluminum alloys have high negative standard reduction potentials, lending them a tendency to oxidize and corrode. Therefore, conversion coatings are applied to aluminum surfaces to provide protection against corrosion.
Conversion coatings describe a surface film formed by a reaction in which a portion of the base metal is converted to a component of the film. As a result of this reaction and conversion, the film becomes an integral part of the metal surface, exhibiting excellent adhesive properties.
Conversion coatings are generally of two types, chemical and electrolytic. With electrolytic conversion coatings, a metal substrate is immersed in a chemical bath and an electric current is passed through the metal component and the chemical bath to form a conversion coating on the surface of the metal. A chemical conversion solution produces coatings entirely through chemical energy, without assistance from an externally applied electric potential.
When treating aluminum with a chemical conversion coating, the chemical conversion coating solution must include an active agent capable of reacting with both the aluminum substrate and an aluminum oxide surface film that forms whenever oxygen reacts with an aluminum surface. Also required is an agent capable of forming an oxide coating on the surface of the aluminum. For example, an oxidizing agent may assist in forming an oxide coating capable of forming an insoluble compound with aluminum or other ions, or an agent may promote coating formation by a controlled hydrolysis reaction.
Several types of chemical conversion coatings have been developed using such chemical compounds as alkaline oxide, crystalline phosphate, amorphous phosphate, chromate, and boehmite. However, the most widely used active agent in conversion coatings is chromate. Applied in acid solutions, chromate coatings provide effective corrosion resistance and self-healing capacity.
In preventing corrosion through chromate conversion coating of aluminum, an aluminum surface is dipped in deionized water to form a gel layer. The gel layer contains aluminum ions in the trivalent [Al (III)] state. Subsequently, chromate ions in the hexavalent [Cr (VI)] and trivalent [Cr (III)] state replace some of the Al (III) ions in the gel layer. Trivalent Cr (III) ions are believed to allow for hardening of the gel layer and hexavalent Cr (VI) ions are believed to promote self-healing by migrating to active corrosion sites. As such, trivalent Cr (III) ions and hexavalent Cr (VI) ions provide two complementary functions with the net effect of a conversion coating characterized by a hard gel and self-healing.
A self-healing capacity is a known characteristic of chromate coatings. Self-healing is in essence a dynamic repair of newly created breaks or defects in the protective film created by the chemical conversion process. The exact mechanism of self-healing is currently not well understood. While not limiting the present invention to a particular theory of operation, the mechanism for self-healing is currently understood to involve migration of hexavalent Cr (VI) ions from a reservoir in the conversion coating to a distant active exposed site to subsequently inhibit corrosion. This phenomenon is evidenced, for example, by the minimal corrosion that occurs after salt-spray testing even when the sample has a scribe mark through the coating to the metal alloy substrate.
However, solutions containing chromium ions in the hexavalent state have been determined to be carcinogenic. The U.S. Environmental Protection Agency (EPA) has included chromium to the list of toxic chemicals for ‘voluntary’ replacement and promulgated strict waste disposal standards to curtail the use of chromium. Strict waste disposal standards and chromium's listing as a toxic chemical have created a need for alternative chemical conversion coating compounds that do not contain the Cr (VI) ion while preserving effective corrosion inhibition and self-repair.
Some chromate-replacement coatings have been developed to avoid the problems associated with chromate coatings. For example, one method for coating aluminum surfaces uses different metals such as selenium, tellurium, titanium, boron, calcium, cobalt, copper, iron, magnesium, nickel, tin, or zirconium. The method includes forming a hydrated oxide film on the aluminum surface (AlOOH.nH 2 O) and treating the oxide film with alcoholates of any of these metals. However, the method suffers from serious problems. It is contended that the use of the method results in a coating inferior to chromium conversion coatings because such coating lacks the complementary functions of hexavalent and trivalent ions. The complementary functions provide for hardness of the aluminum gel and self-healing properties. Additionally, the coatings produced by this method are not designed to provide for dynamic repair of newly created corrosion sites or breaks in the conversion coating layer.
Another method currently available for providing chromium-free coating for aluminum includes immersing the aluminum surface in boiling deionized water to form a gel layer, boehmite, on the aluminum surface. The coating layer is then exposed to an aqueous solution of cerium salts to form cerium oxides within the gel layer. However, the resulting cerium coating suffers from various problems. Cerium ions in the trivalent [Ce (III)] state are not known to migrate to active corrosion sites or breaks, unlike Cr (VI) ions. Because Ce (III) ions are incapable of mimicking Cr (VI) ions, Ce (III) ions are unlikely to provide self-healing in any defects in the coating layer. Cerium coating thus provides less corrosion protection than chromate coatings.
Consequently, in light of the problems associated with presently available aluminum chromate-replacement coatings, there exists an unfulfilled need for aluminum non-chromate coatings that mimic chromate coating interactions with outside environment. In particular, there is a need for non-chromate coatings that provide hardness for the coating and dynamic repair at newly created active corrosion sites, breaks or defects in the coating layer. The invention reported herein fulfills this need.
SUMMARY
An object of the present invention is to provide for non-carcinogenic conversion coatings to replace current carcinogenic chromate coatings.
Another object of the present invention is to provide for non-chromate coatings that mimic chromate conversion coating characteristics.
Another object of the present invention is to provide for a non-chromate coating that provides a combination of self-healing and durable coating features.
Yet another object of the present invention is to provide for a hard, wear-resistant, corrosion-resistant, and paint adherent surface coating to replace current chromate coatings for aluminum and aluminum alloys.
A related object of the present invention is to provide processes for applying chromate-replacement coatings to aluminum and aluminum surfaces.
A further object of the present invention is to provide for non-chromate conversion coatings that use a wide variety of substrate metals.
Another object of the present invention is to provide for ionic coating solutions enabling specific ions to replace aluminum ions in the gel layer on the aluminum surface.
A related object of the present invention is to provide for an ionic coating solution comprising a combination of at least two different ions, with the exception of solutions comprising only manganate ions.
Yet another object of the present invention is to provide for non-chromate conversion coatings comprising hexavalent and trivalent ions.
A more specific object of the present invention is to enable a non-chromate ionic coating for aluminum having ions that migrate to newly created corrosion sites or breaks in the coating layer.
The above-listed objects are met or exceeded by the present invention. The present invention enables the production and use of chromate-replacement coatings on aluminum and aluminum alloys to provide corrosion resistance and dynamic active repair of any newly created corrosion sites. The present invention provides for both trivalent and hexavalent metallic ions to replace aluminum ions in a gel layer on an aluminum surface. It is contended that such substitution of aluminum ions in the gel by hexavalent and trivalent ions from metallic solutions enables such metallic coatings to act like chromate coatings.
A preferred process for coating an aluminum surface includes cleaning the aluminum surface for removing contaminants, and then immersing the aluminum surface in deionized water. A gel layer forms on the aluminum surface by the reaction of aluminum with water. The gel layer is initially amorphous and contains trivalent Al (III) ions. Thereafter, the aluminum surface is treated with any one of the disclosed chromate-replacement conversion coatings.
Prior art solutions suggested the use of covalent bonding coating solutions. The present invention suggests the use of ionic coating solutions. Prior art solutions suggested the use of a single metal for coating aluminum. The present invention provides for the use of at least two metals, with the exception of manganese, which can be used exclusively. Prior art solutions suggested coating aluminum by first forming a porous gel layer, which contains aluminum ions, on the aluminum surface and plugging the pores of the layer with different metals. The present invention suggests forming a gel layer. Prior art solutions suggested using certain metallic compounds that react with the aluminum ions in the gel layer. The present invention suggests partially replacing the aluminum ions in the gel layer. Prior art solutions suggested the use of metallic ions having several oxidation states. The present invention suggests the use of metallic ions having (III) and (VI) oxidation states. Prior art solutions suggested the use of metallic coatings for aluminum surfaces that were not designed to provide for self-healing. The present invention discloses non-chromate coatings for aluminum that provide for self-healing.
BRIEF DESCRIPTION OF THE DRAWING
The above and other features, aspects, and advantages of the present invention are considered in more detail, in relation to the following description of embodiments thereof shown in the accompanying drawing, in which FIG. 1 is a flow diagram presenting common stages in a conversion coating process according to the present invention.
DETAILED DESCRIPTION
The invention summarized above and defined by the enumerated claims may be better understood by referring to the following description. This detailed description of an embodiment, set out below to enable those skilled in the art to build and use an implementation of the invention, is not intended to limit the enumerated claims, but to serve as a particular example thereof. Those skilled in the art should appreciate that they may readily use the concepts and specific embodiment disclosed as a basis for modifying or designing other methods and systems for carrying out the same purpose of the present invention. Those skilled in the art should also realize that such equivalent assemblies do not depart from the spirit and scope of the invention in its broadest form.
The present invention provides for improved chromate-replacement coatings for aluminum and aluminum alloys and an improved process for applying them. In particular, such coatings are produced from conversion coating solutions. Such solutions are metallic ionic solutions applied to aluminum and aluminum alloys surfaces to yield a coating equivalent or superior to that of a chromate coating.
The first step in coating aluminum surfaces is to form a thin gel coating layer over such aluminum surface. When the aluminum surface is treated with deionized water at 50-100 degree centigrade, a porous boehmite layer forms over the aluminum surface. The resulting porous gel-like layer of boehmite is comprised of hydrated aluminum hydroxy oxide (AlOOH.nH 2 O). Such a step is described in U.S. Pat. Nos. 4,988,396; and 5,192,374, all of which are incorporated by reference.
The chemical conversion coating solution of the present invention comprises metallic ions having both trivalent [M (III)] and hexavalent [M (VI)] states to substitute Al (III) ions in the gel-like layer. It is contemplated that the coating solution may also be mixed with wetting agents such as sulfonates that enable uniform and continuous coating. It is also contemplated that the coating solution may include additives such as acetates and nitrates that activate the aluminum surface and control the rate of reaction.
While not limiting the present invention to a particular theory of operation, it is believed that trivalent Cr (III) ions in chromate conversion coatings substitute trivalent Al (III) ions due to similarity in valency and size of the chromium and aluminum ions. Additionally, the secondary hexavalence of chromium Cr (VI) ions may contribute to partial substitution of Al (III) ions. As such, coating solutions having metallic ions in both the trivalent and hexavalent states will interact with aluminum like chromium ions. Thus, the promotion of hardening of the gel upon drying as well as enhanced mechanical strength is believed to occur from M (III) substitution of Al (III) ions in the gel. It is contended that the substitution of M (VI) ions for a portion of the Al (III) ions in the gel is responsible for providing the resulting coating with significant corrosion resistance and the ability to self-heal.
One of the factors that determine when replacement or substitution can occur is the size of a metallic ion relative to aluminum (III) ion. Substitutions can occur when there is a minimal difference in the size of metallic ions relative to aluminum ions. The Hume-Rothery rule allows for the substitution of ions (or atoms) when the ionic (atomic) radii do not differ by more than 15% and when the coordination numbers of the respective ions are the same. Table I illustrates coordination numbers and radii of some metallic ions in either a trivalent (III) or hexavalent (VI) state that exhibit an ionic radius comparable to that of Al (III). Table I is illustrative and not exhaustive.
TABLE I
Metallic Cation
Coordination
No.
(Valence State)
Number(s)
Ionic Radius (Å)
1
Al (III)
4, 6
0.39, 0.54
2
Cr (III)
6
0.62
3
Cr (VI)
4
0.26
4
Ce (III)
6, 8, 12
1.01, 1.14, 1.29
5
Ga (III)
4, 6
0.47, 0.62
6
Mn (III)
6
0.58
7
Mn (VI)
4
0.26
8
Mo (VI)
6, 7
0.59, 0.73
9
Sc (III)
6, 8, 12
0.745, 0.87, 1.116
10
Se (VI)
4, 6
0.50, 0.42
11
Ti (III)
6
0.67
12
Te (III)
6
0.56
13
V (III)
6
0.64
14
W (VI)
4, 6
0.42, 0.60
Note: When an ion exhibits two ore more coordination numbers, the ionic radius increases with increasing coordination number, except for Selenium.
Table I predicts that some elements will replace aluminum ions easier than others provided that all other factors are the same. Manganese (III) ion with coordination number of 6, for example, has an ionic radius of 0.58, which is within Hume-Rothery's 15% difference. Titanium (III) with a coordination number of 6 has an ionic radius of 0.67, which is larger than such 15% difference. It is contended that manganese (III) ions will replace aluminum ions in gel layers more easily than titanium ions will replace aluminum ions, provided that every thing else is same. In such case, manganese (III) ions are preferred over titanium ions. Other factors such as thermodynamics of each substitution reaction, kinetics, pressure, temperature, concentration of reactants will also affect the feasibility of ion replacement.
The present invention may be further understood from the tests that were performed as described in the examples below. In each case, prior to the test, an aluminum substrate was prepared following common process steps illustrated in FIG. 1, as follows:
1. Immersion of an aluminum substrate in Turco 4215 Cleaner™ (52.2 g/l) for 30 minutes followed by a deionized (DI) water rinse. (Turco 4215 Cleaner™ is a tradename for a cleaner manufactured and sold by Turco Products Division of Purex Corporation, Wilmington, Calif.).
2. The aluminum substrate is then immersed in Turco Smut-Go™ (179 g/l) for 10 minutes followed by a DI water rinse. (Turco Smut-Go™ is a tradename for a cleaner manufactured and sold by Turco Products Division of Purex Corporation, Wilmington, Calif.).
The following examples are presented to illustrate superior aspects of the present invention to assist one of ordinary skill in the art in making and using it, and is not intended in any way to otherwise limit the scope of this disclosure or the protection granted by the Letters Patent hereon. These examples are illustrated in FIG. 1 .
EXAMPLE 1
Panels of 2024 aluminum alloy having dimensions of 7.5 cm by 10 cm were immersed in a potassium manganate bath to form a conversion coating. After standard practices of steps one and two, some panels were immersed in boiling deionized (DI) water for 5 minutes. Following the boiling DI water bath, the panels were immersed in various concentrations of potassium manganate for different lengths of time followed by a DI water rinse. Altogether 16 coatings were produced on 2024 aluminum alloy panels. Subsequently, additional coatings were produced on two sets of 6061 and 5052 aluminum alloy test panels having approximately the dimensions of 6.5 cm by 7.5 cm each. Following a completed conversion treatment the panels were exposed to ASTM B 117 salt fog corrosion testing for 24 hours. Table II provides a listing of experimental conditions and the corrosion testing results.
TABLE II
Final
Salt Spray
Boiling
Manganate
Time in
Dip in
Results
Corrosion
Expt.
Coupon
Water
Concen-
Manganate
50%
(No. of
Rating
Number
Number
Used
tration*
Bath
HF
Pits)
Index**
01
01-02
yes
Low
1 minute
yes
TNTC
0/0
01
03-04
yes
Low
1 minute
no
377/325
0/1
01
05-06
no
Low
1 minute
yes
TNTC
0/0
01
07-08
no
Low
1 minute
no
400/480
0/0
02
01-02
yes
Low
5 minutes
yes
TNTC
0/0
02
03-04
yes
Low
5 minutes
no
TNTC
0/0
02
05-06
no
Low
5 minutes
yes
TNTC
0/0
02
07-08
no
Low
5 minutes
no
TNTC
0/0
03
01-02
yes
High
1 minute
yes
TNTC
0/0
03
03-04
yes
High
1 minute
no
395/397
0/0
03
05-06
no
High
1 minute
yes
TNTC
0/0
03
07-08
no
High
1 minute
no
335/323
0/0
04
01-02
yes
High
5 minutes
yes
TNTC
0/0
04
03-04
yes
High
5 minutes
no
187/145
1/1
04
05-06
no
High
5 minutes
yes
TNTC
0/0
04
07-08
no
High
5 minutes
no
229/168
0/1
05
5052
yes
Low
1 minute
no
228
2
Alloy
05
5052
yes
Low
1 minute
no
240
2
Alloy
06
6061
yes
Low
1 minute
no
301
1
Alloy
06
6061
yes
Low
1 minute
no
311
1
Alloy
TNTC = too numerous to count.
*Composition of the manganate bath: “low” concentration = potassium manganate - 10 g/l; potassium hydroxide - 50 g/l; potassium phosphate dibasic - 17.5 g/l; and potassium fluoride - 17.5 g/l. “High” concentration = potassium manganate - 40 g/l; potassium hydroxide - 200 g/l; potassium phosphate dibasic - 70 g/l; and potassium fluoride - 70 g/l.
*Corrosion rating index based on ASTM D 1654; 0 = over 75% of surface corroded, while 10 = no corrosion observed. The conversion coatings were formed without the addition of Al (OH) 3 to the bath.
EXAMPLE 2
Standard practice steps one and two were performed on eight panels of 6061 aluminum alloy having the approximate dimensions of 6.5 cm by 7.5 cm. Subsequently, six out of eight panels of 6061 aluminum alloy were immersed in a DI boiling water bath. The test panels were either placed in the manganate bath directly from the boiling water bath, or air dried with a compressed air jet prior to immersion in the manganate bath. Only the low concentration potassium manganate bath (potassium manganate 10 g/l; potassium hydroxide 50 g/l; potassium phosphate dibasic 17.5 g/l; and potassium fluoride 17.5 g/l) was used because it was found to form coatings with the best corrosion resistance. Additionally, aluminum hydroxide dry gel [Al(OH) 3 ] was added at 10 g/l to the manganate solution. Following the completed conversion treatment the panels were exposed to ASTM B 117 salt fog corrosion testing for 24 hours. Table III provides a listing of the experimental conditions used and the corrosion testing results.
TABLE III
Salt
Cou-
Spray
Corro-
pon
Manganate
Boiling
Air
Time in
Results
sion
Num-
Bath
Water
Drying
Manganate
No. of
Rating
bers
Formulation
Used
Used
Bath
Pits
Index
N1
10 g/l, no
No
No
60 seconds
341
3
Al(OH) 3
N2
10 g/l, no
Yes
No
60 seconds
308
3
Al(OH) 3
N3
10 g/l, no
Yes
Yes
60 seconds
269
3
Al(OH) 3
N4
10 g/l, no
Yes
Yes
30 Seconds
283
3
Al(OH) 3
A1
10 g/l, with
No
Yes
60 seconds
212
4
Al(OH) 3
A2
10 g/l, with
Yes
No
60 seconds
187
4
Al(OH) 3
A3
10 g/l, with
Yes
Yes
60 seconds
238
3
Al(OH) 3
A4
10 g/l, with
Yes
Yes
30 Seconds
161
4
Al(OH) 3
*Corrosion rating index based on ASTM D 1654; 0 = over 75% of surface corroded, while 10 = no corrosion observed.
EXAMPLE 3
Standard practice steps one and two were performed on seven panels of 2024 aluminum alloy having the approximate dimensions of 7.5 cm by 10 cm. Subsequently six out of seven panels of 2024 aluminum alloy were immersed in a DI boiling water bath. The test panels were either placed in the manganate bath after being dried in an oven for three minutes or air dried with a compressed air jet prior to immersion in the manganate bath. Only the low concentration potassium manganate bath (potassium manganate 10 g/l; potassium hydroxide 50 g/l; potassium phosphate dibasic 17.5 g/l; and potassium fluoride 17.5 g/l) was used because it was found to provide the coatings with the best corrosion resistance. Additionally, certain tests added aluminum hydroxide dry gel [Al (OH) 3 ] at 15 g/l to the manganate bath solution. Following the completed conversion treatment the panels were exposed to ASTM B 117 salt fog corrosion testing for 24 hours. Table IV provides a listing of the experimental conditions used and the corrosion testing results.
TABLE IV
Boil
Salt
Cou-
ing
Spray
Corro-
pon
Wa-
Air or
Time in
Results
sion
Num-
Manganate
ter
Oven
Manganate
No. of
Rating
bers
Bath
Used
Drying
Bath
Pits
Index*
96-1950
10 g/l, with
no
Air
60 seconds
396
3
Al(OH) 3
96-1951
10 g/l, with
no
Oven
60 seconds
495
2
Al(OH) 3
96-1952
10 g/l, with
no
Oven
30 seconds
515
2
Al(OH) 3
96-1953
10 g/l, no
no
Air
60 seconds
TNTC
0
Al(OH) 3
96-1954
10 g/l, no
no
Oven
60 seconds
460
2
Al(OH) 3
96-1955
10 g/l, no
no
Oven
30 seconds
450
2
Al(OH) 3
96-1956
No manga-
yes
Oven
Control
TNTC
0
nate used
TNTC = too numerous to count
*Corrosion rating index based on ASTM D 1654; 0 = over 75% of surface corroded, while 10 = no corrosion observed.
EXAMPLE 4
Panels of 6061 aluminum alloy having dimensions 7.5 cm×10 cm were immersed in a solution containing 5 g of floutitanic acid and 5 g of alconox (alkyl aryl sulfonate) in 500 ml of DI water at ambient temperature for about 5 minutes to allow conditioning and activity, followed by a DI water rinse. The panels were subsequently immersed for about 10 minutes in a solution containing 5 g of potassium manganate, 2 g of potassium fluoride, 2 g of potassium hydroxide, 4 g of sodium hydrosulfite (Na 2 S 2 O 4 ) and 40 ml of orthophosphoric (H 3 PO 4 ) acid in 100 ml of DI water with the resulting solution having a measured pH of about 3.4. The panels were rinsed in DI water, allowed to air-dry and subsequently dried for 24 hours in an oven held at 100° F. The panels were then subjected to salt fog corrosion testing per ASTM B117 for 24 hours. Table V provides a listing of the experimental conditions used and the corrosion testing results.
TABLE V
Time in
Salt Spray
Corro-
Boiling
Manga-
Results
sion
Coupon
Water
nate
DI
Oven
No. of
Rating
Numbers
Used
Bath
Water
Drying
Pits
Index*
98-0043-P
No
10
Final
Yes
None
8
Minutes
Rinse
98-0044-P
No
10
Final
Yes
None
10
Minutes
Rinse
*Corrosion rating index based on ASTM D 1654; 8 = over 0.01% corroded, whole 10 = no corrosion observed
In the preceding examples, several compounds were utilized in addition to the metallic ions. The compounds included a uniform coating agent such as potassium fluoride, a base source to facilitate formation of the boehmite gel layer, such as potassium hydroxide, and an acid source to control acidic pH level, such as orhophosphoric acid. In example 1, aluminum panels were exposed to boiling deionized water to form a boehmite coating layer on surfaces of such panel. The panels were then treated in a conversion coating bath. The bath mainly included manganate ions having (VI) oxidation state. No metallic (III) ions were included. In example 2, aluminum panels were subjected to the same process as in example 1 with the exception of a lower concentration of potassium manganate. In example 3, steps similar to examples 1 and 2 were repeated to aluminum panels with the addition of aluminum hydroxide. In examples 1-3, the resulting coating did not provide adequate corrosion resistance.
However, in example 4, potassium manganate was used along with a reduction agent, such as a sodium hydrosulfite. As a result, some of the manganese ions were reduced from (VI) to (III) state. Both (III) and (VI) ions were present in such conversion coating bath. The resulting coating from example 4 exhibited superior corrosion resistance. No corrosion was observed after subjecting the aluminum panels to a 24 hour salt fog corrosion test. Characteristics of improved mechanical strength and self-healing ability were demonstrated.
Other embodiments of the present invention may enable, but are not limited to, the following compositions of conversion coating solutions comprising:
potassium dioxomanganate (KMnO 2 ), potassium manganate (K 2 MnO 4 ), potassium fluoride (KF), potassium hydroxide (KOH), and orthophosphoric acid (H 3 PO 4 )
cerium salt, K 2 MnO 4 , KF, KOH, and H 3 PO 4
gallium salt, K 2 MnO 4 , KF, KOH, and H 3 PO 4
scandium salt, K 2 MnO 4 , KF, KOH, and H 3 PO 4
tellurium salt, K 2 MnO 4 , KF, KOH, and H 3 PO 4
titanium salt, K 2 MnO 4 , KF, KOH, and H 3 PO 4
vanadium salt, K 2 MnO 4 , KF, KOH, and H 3 PO 4
molybdenum salt, KMnO 2 , KF, KOH, and H 3 PO 4
molybdenum salt, cerium salt, KF, KOH, and H 3 PO 4
molybdenum salt, gallium salt, KF, KOH, and H 3 PO 4
molybdenum salt, scandium, KF, KOH, and H 3 PO 4
molybdenum salt, tellurium salt, KF, KOH, and H 3 PO 4
molybdenum salt, titanium salt, KF, KOH, and H 3 PO 4
scandium salt, KMnO 2 , KF, KOH, and H 3 PO 4
selenium salt, cerium salt, KF, KOH, and H 3 PO 4
selenium salt, gallium salt, KF, KOH, and H 3 PO 4
Such embodiments preferably first immerse panels of aluminum alloy in a solution containing deionized water. The panels are then preferably immersed for about 10 minutes in a solution comprising the compositions as listed above or the like. It is contemplated that the panels may be rinsed in DI water, allowed to air-dry. The panels may be subjected to further drying in an oven.
Although the present invention has been described in considerable detail with reference to certain preferred compositions and methods thereof, others are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred embodiments or versions contained herein. | Disclosed are processes and compositions of solutions for chromate-replacement coatings for aluminum and aluminum alloys. A preferred method includes forming a boehmite coating layer that includes Al (III) ions on an aluminum surface, and applying an ionic conversion coating solution to the coating layer. The ionic conversion coating solution comprises hexavalent and trivalent ions. The trivalent ions are selected from the group consisting of Ce, Ga, Mn, Sc, Ti, Te and V. The hexavalent ions are selected from the group consisting of Mn, Mo, Se and W. It is contended that the resulting coatings provide corrosion resistance and self-healing effect in any defects present in the coatings. | 2 |
REFERENCE TO RELATED FOREIGN APPLICATIONS
[0001] This application is related to and claims the benefit under Title 35, United States Code, §119 of Argentina Application No. P040103230, filed Sep. 9, 2004, and Argentina Application No. P050101482, filed Jul. 15, 2005, the teachings of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] This invention refers to a sphygmomanometer which is adaptable to limbs—arms, legs—of different measurements. More particularly, a multi-purpose sphygmomanometer for measuring blood pressure in patients of different ages and physical build, wherefor the manner of usage of this sphygmomanometer may be adapted following various options such as, for instance, adults and children, obese adults and standard size adults, children and neonates. These options are possible thanks to the special construction features of the sphygmomanometer, designed specifically to attain efficiently said purpose.
[0003] Within the previous art in the subject, several types of sphygmomanometers are known, starting with traditional aneroid mercury sphygmomanometers, and up to the most modern designs which use last-generation technology, such as automatic digital sphygmomanometers with electronic memory for recording data pertaining to measurements carried out. With devices of high technological complexity, both those working in conjunction and those used for out-patients, measurements of blood pressure can be taken as well as measurements of other vital signs such as heart rate, breathing rate, etc. Beyond any doubt, the latter include worthy operational features, with useful characteristics and their use is very simple both for professionals and directly for the patients themselves. However, it is not less true that in the above cases, i.e., in mercury, aneroid or electronic technology sphygmomanometers, the need has not been foreseen to adapt them conveniently in order to be able to use them in adults as in children, and even less neonates selectively with a single device.
[0004] It is, then, with a view to overcome the limitations of the aforementioned sphygmomanometers, that the one which is the object of this invention has been developed. In fact, thanks to its outstanding features, this multipurpose sphygmomanometer is adequate for measuring the blood pressure both of adults and children and neonates, both obese and normal, according to such combinations as may prove necessary, with a recording system for all ages and in accordance with varying nutritional conditions. As it will be explained below with reference to the figures which illustrate this sphygmomanometer, for the correct measurement of the blood pressure of each type of patient in particular, it is enough to interchange, super-pose and/or introsuscept (to arrange one inside the other) insufflable chambers, either individual or in compartments and to select the insufflation path as required in each case.
[0005] It is, therefore, the object of this invention, to provide a multipurpose sphygmomanometer for measuring blood pressure in adults, children and neonates, which comprises a clamping band which defines a bracelet, a wrist protector, a wristlet, a leg guard or equivalent to surround the part of the patient anatomy from where the blood pressure is to be measured, with a set of insufflable and selectable chambers, which can be combined one with the other as required, attached to said clamping band, in order to measure the blood pressure of adults, children and neonates, in all cases regardless of their weight and physical condition. The chambers are connected to means of recording blood pressure, to an insufflation pump and to an air-actuated switch or selector device to select the chamber or chambers to be insufflated, individually or simultaneously, depending on the type of patient that is to be handled. According to the various embodiment alter-natives, the chambers may be, for instance, overlapping and at least in part removable one with respect to the others and the clamping band, cleared and isolated from one another by means of a flexible material, arranged one inside the other and/or divided in compartments separated by partitions.
[0006] In one of its forms of embodiment, this sphygmomanometer comprises a selector device which can include one or more inlets which can be connected to one or more outlets, it being possible, in addition, to change the direction of fluid circulation using each inlet as an outlet and vice versa.
[0007] The bidirectional selection and/or combination of inlets and outlets in order to define fluid circulation paths may be made, for example, among:
inlet and an outlet; an inlet and several outlets; several inlets and an outlet; several inlets and several outlets;
[0012] The device drive may be of various types, according to different manufacture features. In fact, according to its type of drive, the switch may be, for example:
Manual: rotating or with linear movement. Automatic: electrical, electromechanical, electromagnetic, air-actuated or hydraulic (as an option with remote actuation and control).
[0015] As it has been mentioned already, one of the preferred uses of this device is to control the injection of air in a multipurpose tensiometer for neonates, children and adults of varying ages and physical builds. To this end, it will be mounted in an appropriate support according to the embodiment involved and the inflatable chambers to be used.
[0016] This switch may be build in different forms and with different materials, such as, for instance, metals, PVC, Teflon, plastic materials in general, rubbers, etc., and any combination thereof, in accordance with the needs of usage.
DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a representative diagram of the sphygmomanometer object of this invention;
[0018] FIG. 2 is a representative diagram of a selector device of the corresponding chamber to be insufflated according to an alternative embodiment of the illustration in FIG. 1 ;
[0019] FIG. 3 is a perspective view which shows an alternative embodiment of the selector device of the chamber to be insufflated applied to the sphygmomanometer;
[0020] FIG. 4 shows the selector device in FIG. 3 now as an integral part of the assembly which includes, as alternative embodiment, the insufflation elements and elements for recording blood pressure;
[0021] FIG. 5 is a representative diagram of one alternative embodiment of the sphygmomanometer which is described, where in this case three chambers to be insufflated are included, each to be used respectively according to the size and age of the patient; and
[0022] FIG. 6 illustrate the manner in which the arm of a patient is wrapped with the appropriate chamber and then adjusted with a clamping band or bracelet for the purpose of measuring his blood pressure; and
[0023] FIG. 7 is a perspective view of the device according to one of the preferred embodiments to be put into practice;
[0024] FIGS. 8 to 10 are representative diagrams of a cross section of a basic or primary embodiment of the device object of this invention;
[0025] FIG. 11 to 14 are representative diagrams of a cross section of a more elaborate alternative embodiment of the device in FIGS. 8 to 10 ;
[0026] FIG. 15 to 18 are representative diagrams of a cross section of an alternative embodiment shown in FIGS. 11 to 14 ;
[0027] FIG. 19 is an elevated view in partial cross section of the device according to the embodiment of FIG. 7 , where several transverse planes are shown corresponding to the illustrations in FIGS. 20 to 23 ;
[0028] FIG. 20 to 23 are representative diagrams of the transverse cuts shown in FIG. 5 ;
DETAILED DESCRIPTION OF THE INVENTION
[0029] Firstly, with reference to the diagram of the sphygmomanometer in FIG. 1 , identified with general reference number 1 , a clamping band 2 can be seen, which defines a bracelet, a wrist protector, a wristlet, a leg guard or equivalent, which includes tissue 3 a and 3 b of the “thistle” type, the latter attached to the obverse of band 3 , for adjusting same on the anatomical part of the patient from where his blood pressure will be measured. In practice, band 2 may be optionally made of a rigid, flexible or elastic material, of tissue or cloth of any type, as deemed more appropriate, preferably with standard attachment fittings.
[0030] According to this first embodiment, on band 2 a set of insufflable chambers is arranged, which include a chamber 4 required to measure blood pressure in adults and a chamber 5 required to measure blood pressure in children as well as in neonates or for general pediatric use. As shown, chambers 4 and 5 overlap one with the other, are removable at least in part one from the other and from the band or bracelet 2 and each one of them includes an extension positively related to the size and age of the patient, chamber 4 (for adults) being used for larger widths and lengths than chamber 5 (for children or neonates).
[0031] According to the alternative embodiments foreseen for sphygmomanometer 1 , chambers 4 and 5 may be fixed in whole or in part and removable one from the other and from the surface of band 2 , in whole or in part, divided inside in compartments by means of laminated flexible material or by means of transverse or longitudinal, or introsuspected partitions, i.e., arranged one inside of the other.
[0032] The set comprised of chambers 4 and 5 is connected to an insufflation pump, defined by a rubber knob 6 with an air discharge cock 6 , through respective air conduits 7 a and 7 b for chamber 4 , 8 a and 8 b for chamber 5 , and a selector device by means of which air is channeled to one sleeve or the other as required. Said conduits 7 a and 7 b , or 7 A to 7 c , may be parts of separate paths, as illustrated, or may be part of a single hose or “multi-lumen”. The same is valid for conduits 8 a and 8 b.
[0033] Selector device 9 is defined by an air-actuated selector switch 9 which, in this first embodiment, is a two-way rotary switch actuated by a knob 10 , or else, as it will be seen below, a linear lever-actuated switch. Depending on the number and configuration of the chambers, switch 9 may also be a three- or two-way device. Selector device 9 is provided with an air inlet connected to knob 6 by means of conduit 7 c and a device to record or read blood pressure, in this case of the aneroid or manometer type identified with reference number 11 by means of conduit 8 c.
[0034] It should be pointed out that to read blood pressure in practice a recording device could likewise be used, of the mercury column or digital electronic type, among other possible types, as it may be deemed more appropriate eventually. In addition, both the recording means and the insufflation means may be portable, with a mobile or wall-mounted support.
[0035] FIG. 2 shows schematically an alternative embodiment where se-lector switch 9 is housed in a receptacle, identified with reference number 12 , together with manometer 11 and an automatic insufflation pump (not shown) which may be, for example, electronic or electromechanical, among other possibilities. In this case, in receptacle 12 , an insufflation push-button 13 and an air-discharge push-button 14 are included, related from the operational standpoint to the air pump housed therein.
[0036] In the embodiment variant shown in FIG. 3 , it is clear that the selector device in the chamber to be insufflated, applied to the sphygmomanometer and, in particular, the selector switch identified now with reference number 30 , is of the type actuated by means of a linear lever 31 . This se-lector switch 30 may be based on an operating principle similar to that of switch 9 of the previous embodiment and, in general, may be any type of air-channeling path selector switch for various possible applications. As shown, the connections of selector switch 30 with rubber knob 6 and manometer 11 through conduits 7 c and 8 c , on the one hand, and the connections for the corresponding chambers through the “single-lumen” or “multi-lumen” conduits 7 a , 7 b , 8 a and 8 b , on the other, are the same as those illustrated in FIG. 1 .
[0037] Depending on the number of chambers associated with clamping band 2 , switch 9 and switch 30 will be, for example, six-way (two inlets and four selective outlets), or eight-way (two inlets and six selective outlets).
[0038] In FIG. 4 , another alternative embodiment is shown, where selector switch 30 is connected as an integral part of an assembly where it inter-faces with the same rubber knob 6 and manometer 11 , i.e., without conduits 7 c and 8 c , while the chambers to be insufflated, as before by means of the conduit sets identified by references 7 and 8 , in this case of the “multi-lumen” type, although they could be individual conduits of the “single-lumen” type. This alternative embodiment is, thus, a compact assembly which can be handled with one hand.
[0039] In the diagram in FIG. 5 , an alternative embodiment is shown, where the sphygmomanometer includes a set of three chambers, each one of them to be used respectively according to the size and age of the patient. Indeed, in this embodiment three chambers are included, where the first chamber 32 , the one with the longest range, is designed to be used with obese adults, a second chamber 33 , with medium range, to be used with standard-sized adults, and a third chamber 34 , with a lesser range than the previous ones, for general pediatric use. Chambers 32 , 33 and 34 are connected to respective pairs of air conduits, respectively identified now by reference numbers 35 , 36 and 37 . In addition, preferably in this embodiment, chambers 32 , 33 and 34 are an integral part of a single, indivisible structure and are separated and isolated one from the other by means of flexible materials making up partitions which separate the chambers. Thus, considering that the three chambers 32 to 34 as a whole define a single sleeve divided in three compartments or chambers by means of partitions, the sleeve shall perform the function of two, three or eventually more overlapping chambers should it be appropriate to add additional chambers. As it will be understood, if in practice it is deemed appropriate, all three chambers may as well be partitionable, one from the other as well as with respect to the clamping band 2 . In addition, in this embodiment with partitioned chambers, two, three or more chambers may be used. In accordance with the number of chambers, a selector switch will be used, with the number of paths required in each case. In general, the width of the chambers may range, for example, from 3 to 18 cm or more, with several inter-mediate values depending on the type of patient, i.e., neonates, children, adults and obese adults.
[0040] The same FIG. 5 is useful for referring to the embodiments of the sphygmomanometer where the set of chambers is comprised by chambers arranged one inside the other, as well as when the chambers are divided in separate compartments which may be selected individually or together using the selector switch, in all cases to respond to operational needs ac-cording to the type of patient that is to be handled.
[0041] Indeed, for example, chamber 34 may be arranged inside chamber 33 , or else chamber 33 inside chamber 32 , or else chamber 34 inside chamber 33 and these two inside chamber 32 . In addition, as it will be understood, the perimeter configuration, the surface defined by the contour of each chamber and the relative location may vary depending on practical considerations regarding the manufacture of the sphygmomanometer.
[0042] Regarding the other alternative embodiment, where chambers are divided in compartments separated by partitions, numerical references 32 , 33 and 34 in this case must be construed as the compartments or chambers in which a single sleeve is divided and, thus, the lines delimiting the length and width of each pertain to partitions separating said compartments. Similarly to what was said regarding the annotated preceding alternative, both the geometrical configuration as well as the total extension or surface of each compartment and the relative location between them may vary depending on what is more convenient in practice from a technical point of view.
[0043] To use this sphygmomanometer and, in particular, when it takes, for example, the first preferred embodiment, initially the arm of the patient is wrapped with it or the chambers, depending on what is required for each type of patient, together with a stethoscope, while keeping clamping band 2 deployed, as shown in FIG. 7 . If only one of the chambers is to be used, alternatively all chambers may be kept attached to band 2 , or else those chambers which are not required at that point in time may be removed.
[0044] Next, the chamber(s) and the stethoscope are attached and wrapped with clamping band 2 , whereupon all steps previous to the reading of the patient blood pressure are completed. In this FIG. 7 , general reference number 38 is used to identify any single one of the chamber embodiments, i.e., independent, separable, partitioned, introsuspected or any combination of these different configurations, while reference number 39 is used to identify the arm of the patient, regardless of his age and size.
[0045] When put into practice, this sphygmomanometer may include optionally, a scale to select the insufflable chamber recommended to use, depending on the circle of the arm whose blood pressure is to be taken.
[0046] To be precise, this is a metric scale denominated in centimeters, although in practice any other type of scale may be used, such as international, calorimetric, etc., or measuring or weighting. Thus, the insufflable chamber to be used may be selected according to age, build and nutritional condition of the patient. This scale may be, for example, attached to the bracelet of the sphygmomanometer used, both in the case of a traditional sphygmomanometer as well as with the multipurpose sphygmomanometer object of this invention.
[0047] The incorporation of the scale to the chambers, made of cloth, vinyl or another type of support, may be by means of a tape with the relevant scale attached, stitched or fixed by any means, as well as by printing on the bracelet or the chamber, on its internal or external surface, in its edges or central areas.
[0048] Preferably, the scale used shall follow international practices. The insufflable chambers to be selected through the relevant paths shall have their match or equivalencies in the aforementioned scale. In this case, the scale is related to the coverage of approximately 80-100% of the brachial perimeter at the middle part of arm, as per international standards. A table follows which includes the measurements pertaining to chambers recommended according to the variables to be born in mind in each case.
[0049] For the values quoted in this table, the chambers defined by the classical insufflable chambers or their equivalent in chambers such as those of the multipurpose sphygmomanometer of this invention have been taken as reference.
Chamber Chamber Width/length Covering 80% to Color width length Standardization 100% of perimeter of 100% Covering Range Standardization Index Scale Age [cm] [cm] Index limb Range [cm] 80% Covering Range % of perimeter of limb Yellow New Born 4 10 0.4 10 100%: up to 10 0.33 to 0.6 80%: up to 12 0.40 + 1/−7 Green Unweaned 6 15 0.4 10.1 to 18 100%: up to 15 0.33 to 0.59 80%: up to 18 0.40 + 12/−7 Orange Child 8 20 0.4 15.1 to 24 100%: up to 20 0.33 to 0.52 80%: up to 24 0.40 + 12/−7 Violet Adolescent 10 25 0.4 20.1 to 30 100%: up to 25 0.33 to 0.49 Small Adult 80%: up to 30 0.40 + 9/−7 Brown Adult 12 30 0.4 25.1 to 36 100%: up to 30 0.33 to 0.47 80%: up to 36 0.40 + 9/−7 Pink Obese adult 15 37.5 0.4 30.1 to 45 100%: up to 37 0.33 to 0.49 80%: up to 45 0.40 + 9/−7 White Very obese 17 42.5 0.4 37.5 to 51 100%: up to 42 0.33 to 0.45 adult or thigh 80%: up to 51 0.40 + 8/−7
[0050] The colors in this reference table coincide with the range of values highlighted with colors in the aforementioned scale for selection of the insufflable chamber recommended for use.
[0051] The operating procedure is summarized below.
[0052] The proper chamber or bracelet is placed around the arm of the patient and the scale is read, which scale may include colors to help speed up the relevant reading, and the location where point “0” or beginning of the scale coincides with the other point, or point of contact, is determined, and subsequently the scale is sufficiently adjusted to the arm, so that the choice of the proper chamber is more trustworthy.
[0053] If this point of contact is established, for example, in the “orange-colored” area, the sleeve corresponding to this color is chosen or selected, for example, the chamber for children, 13.9 cm long by 9 cm wide. In this case in particular, the scale includes seven colors from small to large (yellow, green, orange, violet, brown, pink and white). These colors relate to the different inflatable chambers with different measures to be used as already mentioned. The number of inflatable chambers and matching colors in the scale shall vary according to their number, depending on the number of utilities or tensiometer chambers.
[0054] It should be pointed out that the name of the insufflable chambers ac-cording to their ethereal name (RN, breast-fed babies, adults, etc.) does not necessarily coincide exactly in practice with the patients and, instead, are valid as mere guidelines for usage. That is why this scale indicates approximately which insufflable chamber is more adequate according to nutritional condition, age, size, etc. of the patient.
[0055] It becomes clear, then, that thanks to its outstanding structural features in any of its alternative embodiments, this tensiometer allows the use of chambers, individually or combined one with the other depending on each patient in particular, which is not possible with conventional tensiometers existing to this date.
[0056] In FIG. 7 , a multi-way selector device 101 is shown; it comprises an outside body or carcass 103 inside which is housed the inside body or rotary drum 102 , wherein a longitudinal attachment of fluid-channeling sectors 104 A to 104 D is defined, hermetically isolated by means of sealing rings 105 . The carcass 103 is closed at the bottom by a cover 6 , while at the top it has an opening 107 through which passes a cylindrical projection 108 of rotary drum 102 for coupling an actuating handle 109 . Matching each one of said fluid-channeling sectors 104 A to 4 D of drum 102 , carcass 103 is provided with orifices communicating with the outside wherein are coupled fluid inlet and outlet spouts where the respective hoses or cannulae are coupled.
[0057] According to this embodiment, the valve includes a fluid-injection spout 110 , a spout 111 for connection to the manometer, and fluid-outlet spouts 112 A to 112 D for feeding and actuating the hydraulic or air-actuated devices the operation of which must be controlled by means of valve 101 .
[0058] Depending on the position of actuating handle 109 , and therefore the relative position of rotary drum 102 and carcass 103 , the device 101 is kept closed or a selective and combined communication is established between the fluid inlet spout or simply inlet 110 and one or several of outlets 112 D to 112 D. In other words, in a first position of drum 102 , the passage of fluid between inlet 110 and all outlets 112 A to 112 D is blocked, while at the four remaining positions successive communications are established between inlet 110 and each one of outlets 112 A to 112 D, with one of the outlets joining in each one of the positions.
[0059] As it will be understood, the sequence and combination in which the flow of fluid is enabled from inlet 110 to outlets 112 A and 112 D depends on the peculiarities of rotary drum 102 in its various possible forms of embodiment depending on what is more convenient in practice for each case of application of this valve. For instance, in the same manner as FIG. 7 shows that outlets 112 A to 112 D are aligned along carcass 103 , these may likewise be arranged following an helicoidal geometry, aligned along the perimeter as a whole or in pairs on a single transversal plane, or even all of them arranged axially on the base of the valve body and, more precisely, the base of the carcass to which cover 106 is shown coupled.
[0060] The diagrams in FIGS. 8 to 10 , where the same reference numbers are kept for parts equivalent to those shown in FIG. 7 , show a basic embodiment of the valve of this invention which may belong to any one of sectors 104 A to 104 D of same, or else a combination of two adjacent sectors. Starting with FIG. 8 , drum 102 is shown to be provided with a channeling conduit 113 which stretches transversally following a geometrical chord defined on the circular section of said drum 102 . As FIG. 8 shows, the relative position of drum 102 and carcass 103 corresponds to the “closed switch” condition, with inlet 110 cut off from the outlets now identified by means of references 114 A and 114 B. When drum 102 is turned to reach the position shown in FIG. 9 , conduit 113 establishes communication between inlet 110 and outlet 114 A, allowing fluid to go through as indicated by arrows F. In like manner, when drum 102 turns to reach the position illustrated in FIG. 10 , communication is established between inlet 110 and outlet 114 B. Thus, device 110 operates as a switching key between inlet 110 and one of the outlets 114 A and 114 B. If, as it has been mentioned, the illustration in these FIGS. 8 to 10 matches with some of the sectors of device 101 defined on the same transversal plane, one will have as many possible combinations of fluid outlets as sectors are formed in device 101 .
[0061] In FIGS. 11 to 14 , another embodiment of device 101 is shown with, for instance, three fluid outlets aligned along the perimeter on a single transversal plane, where the rotary drum includes sections of channeling conduits which branch into sections of outlet conduits. The ends of each one of these sections of channeling conduits are selective and can be made to face the outlet orifices of device 101 in a selective and combinable manner in order to establish several paths of communication between fluid inlets and outlets. Indeed, drum 102 of device 101 now has formed a plurality of fluid channeling conduits which may be combined one with the other, forming two groups of conduits: On the one hand, inlet conduits 115 A and 115 D and, on the other, outlet conduits 116 A to 116 D, which project radially from a central chamber 117 . When drum 102 is in the relative position to carcass 103 shown in FIG. 11 , device 101 is kept closed, as fluid inlet 110 is not communicated with any of the inlet channeling conduits 115 A to 115 C. Instead, when drum 102 is turned to the position shown in FIG. 12 , conduit 115 A is faced with inlet 110 and, consequently, fluid circulation is enabled towards outlet 114 A through conduit 115 A, central chamber 117 and outlet conduit 116 A. When drum 102 is turned to the position illustrated in FIG. 13 , inlet conduit 115 B is faced with inlet 110 , outlet conduit 116 A is faced with outlet 114 B and outlet conduit 116 B is faced with outlet 114 A and, in this manner, fluid circulation from inlet 110 to outlets 114 A and 114 B is enabled. Finally, as shown in FIG. 14 , when the drum is placed so as to face inlet conduit 115 C at fluid inlet 110 , outlet conduits 116 A, 116 B and 116 C are faced, respectively, with outlets 114 C, 114 B and 114 A, with fluid circulating now from inlet 110 simultaneously to the three outlets aforementioned. As it will be understood, the number of fluid-inlet and fluid-outlet channeling conduits of rotary drum 102 , in practice, may vary depending on the number of fluid-outlets required in particular in each case this device 101 is applied.
[0062] In FIGS. 15 to 18 , an embodiment is shown of device 101 , the parts of which equivalent to those already described are identified by means of the same reference numbers, where the rotary drum includes a fluid-inlet conduit which branches into three outlet conduits and where the ends of each one of said channeling conduits likewise and may be selected and faced jointly with the respective outlets of device 101 . However, in this case the inside surface of carcass 103 has a pre-chamber 118 in the shape of a circle arc which allows selective communication of fluid inlet 10 with the channeling conduit of inlet 115 and one or more of inlets 114 A to 114 C through central chamber 117 and conduits 116 A to 116 C. The extension of said pre-chamber is at least equal to the distance between the adjacent ends of conduits 116 A to 116 C which face outlets 114 C to 114 C. Thus, it may be said that pre-chamber 118 allows the replacement of two of the three inlet conduits 115 A to 115 C of the embodiment shown in FIGS. 11 to 14 . In addition, pre-chamber 118 may eventually extend also along drum 102 so as to intercommunicate two or more sectors of device 101 in each of which one or more fluid outlets is formed. Thus, the diagrams shown in these figures may relate to one of the various sectors of device 101 , defined in respective transversal planes of the body thereof.
[0063] In this way, as device 101 has only one fluid inlet 110 , pre-chamber 118 enables communication between said inlet 110 and the respective fluid outlets pertaining to each one of those sectors. It is readily evident that pre-chamber 118 may take in practice several shapes depending on he number of fluid outlets which must be arranged in each case of application of device 101 .
[0064] The elevated and partially sectional view of device 101 which is shown in FIG. 19 and which relates essentially to the embodiment illustrated in FIG. 7 , highlights in addition some of the peculiarities of drum 102 in relation to carcass 103 in a position which establishes communication between fluid inlet 110 and outlets 112 A and 112 D; this may be under-stood more clearly in the diagrams of FIGS. 20 to 23 . It should be pointed out, for purposes of simplifying the illustrations, that although in FIG. 7 references 112 A to 112 D have been used to identify fluid outlet spouts, now, the same reference numbers indicate directly the fluid outlet orifices formed in carcass 103 .
[0065] In like manner, as was the case in the figures already described, now fluid inlet 110 and the connection of manometer 111 match spouts 115 and 111 in FIG. 7 . In this FIG. 19 one can see that rotary drum 102 includes a longitudinal chamber 119 from which a succession of outlet conduits 120 A to 120 C, which relate respectively to each one of outlets 112 A to 112 C of the sectors defined according to transversal planes A-A to C-C, projects radially. Pre-chambers 122 B to 122 D, the configuration of which will be clearly shown in the following figure, are likewise depicted.
[0066] Indeed, FIGS. 20 to 23 show, between rotary drum 102 and carcass 103 , matching transversal planes B-B to C-C, the configuration of respective pre-chambers 122 B to 122 D in the shape of a circle arc, which complete the selective communication of outlets 112 B to 112 D with fluid inlet 110 and the connection of manometer 111 through chamber 119 and conduits 121 B to 121 D. As shown, said pre-chambers 122 B to 122 D are of different lengths in each of the transversal planes, are defined in partly overlapping positions according to planes which are perpendicular to same, so that a selective and combined communication between any of the matching channeling conduits may be established and, consequently, with any of inlets 112 B to 112 D, with fluid inlet 110 and manometer connection 111 . According to optional alternative embodiment options, pre-chambers 122 B to 122 D may also be formed in carcass 103 or else may include an arc portion formed on the rotary drum 102 and another portion formed in carcass 103 . The selection of fluid outlets, for example, identified by means of reference numbers 112 A to 112 D will depend on chambers 4 5 to be used with the sphygmomanometer, which may be partitioned, introsuspected, overlapping, detachable, etc.
[0067] In the case of introsuspected or overlapping chambers, the fluid out-lets used shall be equivalent to the number of inflatable chambers. For ex-ample, five different sleeves may be actuated sequentially according to the needs of usage turning the rotary drum 102 by means of handle 109 .
[0068] In the case of partitions or equivalent chambers, actuation of same shall be sequential, and adding from small to large in general, depending on the need to use it for neonates, children, adults of obese subjects, or any other intermediate patient.
[0069] In each case, the variant shall relate in the main to the configuration of the conduits of rotary drum 102 which, instead of having a single communicating conduit enables to operate sequentially, shall have several to operate in sequence and addition, with each one communicated with a set number of chambers, equivalent to the number and configuration of conduits available in the rotary drum.
[0070] Moreover, as an outlet is selected and others are enabled, different equivalences to conventional insufflable chamber of different sizes shall be achieved. | A sphygmomanometer device for measuring the blood pressure of all ages of patients including a flexible band having a plurality of insufflable chambers, with each chamber structurally arranged to communicate with an insufflation pump. The insufflable chambers are sized to the age and physical condition of the patient when the flexible band is applied about the patents arms or legs to determine the patients blood pressure. | 0 |
FIELD OF THE INVENTION
The present invention relates to power amplifiers in general, and, more particularly, to high-efficiency audio power amplifiers, especially for battery-operated applications.
BACKGROUND OF THE INVENTION
A major problem associated with power amplifiers is inefficient use of electrical energy. Especially for audio applications, and more specifically in battery-operated portable audio applications, improving the efficiency of the power amplifier has major benefits in terms of performance as well as cost.
Most of the inefficiency of power amplifiers is a result of power dissipated within the power stage. The dissipated power is a function of the difference between the supply voltage and the output voltage of the power stage. In applications such as audio, where the peak-to-RMS ratio is high (about 12 dB), the peak dictates the supply voltage, but, most of the time the output voltage is significantly lower, and thus a significant amount of power is dissipated in the power stage.
Power dissipation (typical to class-A, AB, B, C, D, and Pulse Width Modulation (PWM), and/or output-of-band noise energy (typical to class D and PWM), is the main cause of inefficiency in prior art power amplifiers, and results in excessive electrical power consumption. The heat developed in the power stage must be dissipated, and the need to provide for adequate heat removal impacts the design and performance of integrated circuit components, and requires design compromises and special engineering expertise.
Further limiting factors associated with prior art power amplifies include limitations in their dynamic range (limited by the power-supply voltage), and their inability to achieve output over the full supply voltage range (“rail-to-rail” operation). Moreover, additional major problems in the design of existing power amplifiers include non-linearity and noise.
When designing a power amplifier, these factors—efficiency, linearity, dynamic range, and freedom from noise—conflict with one another, and optimizing the design to overcome one will compromise the design's ability to overcome the others.
It is already known in the art that by employing a tracking power-supply which minimizes the difference between the power-supply voltage provided to the power stage and the required output voltage of the power stage, that the dissipated power may be minimized. The minimizing action of a track power-supply is herein denoted by the terms “track” and “tracking”, and is effected by providing a target function for determining the output of the tracking power-supply. The arguments of the target function may include the input signal to the power amplifier as well as the internal input to the power stage. There are, however, difficulties in implementing a tracking power-supply that is in itself efficient and suitable for a given application. For example, in the prior art are known tracking power-supplies which are based on switched L-C circuits. Because L-C circuits are reactive and store rather than dissipate energy, such tracking power-supplies are efficient. Unfortunately, the inductors of L-C circuits are not suitable for use with integrated circuits, and therefore such prior-art tracking power-supplies are not useful in applications involving miniaturized and/or battery-operated equipment.
There is thus a widely recognized need for, and it would be highly advantageous to have, a high-efficiency power amplifier with linear response, low noise, and with a wide dynamic range. These goals are met by the present invention.
REFERENCES
[1] EP0998795, WO9905806 “Method and apparatus for performance improvement by qualifying pulses in an oversampled, noise-shaping signal process”
[2] EP0906659, WO09749175 “Oversampled, noise-shaping, mixed-signal processor”
[3] “Relationships between Noise Shaping and Nested Differentiating Feedback Loops”, by J. Vanderkooy, and M. O. J. Hawksford, Journal of the Audio Engineering Society, Vol. 47, No. 12, December 1999.
TERMS AND DEFINITIONS
Tracking Power-Supply—A power-supply capable of providing a variable output voltage to suit the needs of a power amplifier. According to the present invention, an efficient tracking power-supply is implemented, having control logic controlling a network of switched capacitors. By controlling the switches, different network connections can be made, giving rise to different electrical circuits. This allows creating multiple supply voltages with high efficiency at the load terminals, and monitoring voltages through the sensor terminals.
Multi-Level Quantizer—The above tracking power-supply can be viewed as a quantizer (a “multi-level quantizer”) with multiple output levels possible during different time intervals, where the level changes during each time interval according to the voltages on the capacitors.
Network of Switched Capacitors—the network of switches and capacitors used in the tracking power-supply.
Network Connection—This is a specific set of connections, created by controlling the switches of the network of switched capacitors. This set of network connections creates an electrical circuit involving some or all of the capacitors, supplies, load terminals and sensor terminals.
Network State—The state of the network of switched capacitors at a certain time. The voltages across the capacitors define the network state.
I-Bit State—a specific case of a network state where a 1-bit state per capacitor indicates whether the voltage over it is higher or lower than some target voltage. This is useful when implementing the target capacitors selection algorithm.
Sensor—A sensor is any means of monitoring the network state while causing minimal affect. To monitor voltage over a certain capacitor, an appropriate network connection can be made by the control logic. A sensor for the 1-bit state can be the output of a comparator, comparing the voltage over the capacitor to the target voltage.
Estimated Network State—An estimated network state is a network state where some or all of the capacitor voltages are estimated rather than directly monitored.
Network Parameters—The network parameters include sufficient information about components involved in the work of switched capacitors. By way of example, this information may include electrical parameters of the load and main supplies, the capacitance of each capacitor, and the time intervals, whether absolute or relative. In certain embodiments of this invention, the control logic may need to known network parameters in order to estimates, or predict, the estimated network state when direct monitoring is not feasible. The network parameters may be supplied to the control logic, or may be measured by the control logic through the sensor, whether during initialization time, during operation, or both.
Time Interval—A period of time during which the network connection is held fixed. The duration of such time intervals may be constant or variable, depending on the application.
Load Time Interval—A time interval during which the network connection involves the tracking power-supply output terminals.
Monitoring Time Interval—A time interval during which monitoring of the network state can be performed. A monitoring time interval can overlap a load time interval.
Control Logic—Logic controlling the network of switched capacitors via the switches, in order to create a desired network connection. The main task of the control logic is to determine the best network connection involving the load at any time interval. The control logic implements a selection algorithm, and attempts to minimize the value of the target function, while conforming to some other criteria. The control logic may be implemented fully in the digital domain, while monitoring the state of the network of switched capacitors through the sensor. Alternatively, the control logic can be implemented in the analog domain. The control logic unit has one or more inputs and one or more control outputs.
Target Function—At each load time interval, there is an ideal desired output from the track power-supply. Since in general the tracking power-supply cannot provide this output exactly, the target function is a ‘cost’ function that associates a cost with each possible output from the tracking power-supply during the current load time interval. The control logic uses this function as part of the selection algorithm to determine the best network connection for the current load time interval.
Selection Algorithm—The selection algorithm applied by the control logic tries to minimize the target function, while applying additional considerations as well. Such considerations can be of different natures, including, without limitation, minimizing the number of switching operations taking place, keeping voltages on capacitors within certain ranges, keeping voltages on capacitors close to a target voltage, maintaining certain characteristics of the power stage, and so forth.
Constrained Capacitors—A selection algorithm according to which each capacitor has a target voltage range, and where the capacitor is not allowed to be connected such that it would charge when the voltage across it is above its target voltage range, and vice versa.
Targeted Capacitors—A selection algorithm according to which each capacitor has a target voltage, and where the capacitor is not allowed to be connected such that it would charge when the voltage across it is above its target voltage, and vice versa.
Target Error—The error, in the case of the targeted capacitor selection algorithm, of the actual average voltage supplied by a capacitor during a load time interval relative to that capacitor's target voltage.
Power Stage—The final stage of the power amplifier. Embodiments of the present invention describe a linear power stage and a discrete power stage.
Linear Power Stage—A power according to the present invention having a linear-analog power stage, where the power-supply is a tracking power-supply. The advantage of this approach is that the PSRR (Power Supply Reduction Ratio) that is an inherent feature of a linear analog power stage, reduces the noise generated by the tracking power-supply at the final output.
Discrete Power Stage—A power amplifier according to the present invention having no analog power stage, where the tracking power-supply is connected directly to the power amplifier output, and acts as a Multi-Level Quantizer. In this approach, the noise-shaping loop handles all noise. No linear-analog power components are used, and this is an advantage in certain cases.
Noise-Shaping Loop—A feedback and filtering network that causes the noise energy (whether non-linear errors correlated with the input, or uncorrelated noise) to reside in frequencies where the noise poses no problem. In the audio case, the power amplifier noise energy is shaped into high, inaudible frequencies. In one embodiment of the present invention, the noise-shaping loop may be implemented entirely in the analog domain, around the power stage. Alternatively, in another embodiment of the present invention, the noise-shaping loop may be implemented entirely in the digital domain before the power stage, based on information supplied by the control logic. In yet another embodiment, the noise-shaping loop may be implemented as a hybrid digital-analog domain using an A-to-D converter to convert analog feedback from the output of the power stage into the digital domain.
SUMMARY OF THE INVENTION
The main goal of the present invention is to improve the efficiency performance of power amplifiers, in order to reduce electrical power consumption. Another goal is to reduce the impact of critical factors on the design of power amplifiers, and allow for more tradeoffs regarding different parameters typical of power amplifiers such as dynamic range, signal-to-noise ratio, and harmonic distortion. Another goal is to improve the efficiency of DC-to-DC converters and tracking power supplies.
According to the invention, a non-linear, switching-type tracking power-supply is used to eliminate most of the power dissipation, as well as to increase the supply voltage (and thus the dynamic range) to the power stage by utilizing voltage multiplication techniques. A novel aspect of the present invention is the use of an integral feedback control and noise-shaping unit to correct the switching noise, common mode noise and the non-linearity introduced by such a power-supply. This innovation allows utilizing a tracking power-supply that is easy to design as well as inexpensive to manufacture and use, and which is well-suited for integrated circuitry, but which may otherwise normally exhibit an excessive amount of inherent noise. One embodiment of the present invention uses a linear power stage for which supply voltage is taken from a tracking power supply to significantly decrease power dissipation within the power stage. Another embodiment of the present invention uses a discrete power stage, where the final power amplifier output is taken directly from the tracking power supply. Yet another embodiment of the present invention uses the tracking power supply as a high efficiency DC-to-DC converter.
FIG. 1 is a general block diagram illustrating the basic configuration of a linear power stage power amplifier according to the present invention. A primary power source 102 is the source of DC electrical energy, having a positive output V dd 102 -A and a negative output V ss 102 -B, which feed into a tracking power-supply 104 . Tracking power-supply 104 receives control input from a noise shaper 106 via a control output 106 -B, as well as from an input 106 -D and an input 106 -E from an output 106 -C of the noise shaper 106 . Tracking power-supply 104 provides a positive supply voltage V+ 104 -A and a negative supply voltage V− 104 -B to a power stage 108 , with power output terminals 108 -A (L+) and 108 -B (L−), which output an amplification of an input signal 110 at an input 106 -A. There is at least one supply voltage involved (which is the voltage furnished to power stage 108 ), and the illustration herein of a positive supply voltage and a negative supply voltage is as a non-limiting example. In another embodiment, a single supply voltage can be utilized in conjunction with a point at a common or ground potential. Where two distinct supply voltages are utilized (such as a positive supply voltage and a negative supply voltage), the term “supply voltage” wherein denotes the voltage difference between these two distinct supply voltages. In another embodiment, the polarity of the positive and negative can also be interchanged in order to also create a negative voltage difference between these two distinct supply voltages. In a similar manner, primary power source 102 is illustrated in this non-limiting example as having positive output V dd 102 -A and negative output V ss 102 -B, but it is also possible to output a single source voltage relative to a point at a common or ground potential, and, where there are distinct source voltages for both a positive output V dd and a negative output V ss , the difference between these two distinct voltages is referred to as the “source voltage”. As noted previously, noise shaper 106 provides feedback control of tracking power-supply 104 via an output feedback 122 from a differential amplifier 120 to minimize the affect of noise and non-linearity at output 108 -A and 108 -B. Also, power stage 108 receives an internal input 106 -F from noise shaper 106 . The input signals from noise shaper 106 help in predicting the required tracking target function. An output load 112 represents the driven audio load, such as a loudspeaker, and in general may be a combination of resistive and possibly reactive elements. An important criterion of power amplifier operation is how closely the output of the power amplifier matches a specified transform of the input signal. The simplest and generally most-desired such transform is that of a multiplicative constant over a specified frequency range, herein denoted as the “amplification” K. The difference between the actual output and the transform is herein denoted as the “error” of the power amplifier.
A general reference for noise shaping loops in both the analog and digital domains is [3].
As is known in the art, the use of feedback can reduce non-linear behavior of an output circuit by applying a feedback from output to input and invert the non-linear behavior. In addition to reducing non-linearity through the use of feedback, the noise shaper also reduces the uncorrelated audible noise of the output signal. It is known in the art that through the use of an auditory sensitivity filter a noise shaper can shift the frequency spectrum of the uncorrelated noise away from the audio spectrum to higher, substantially non-audible frequencies (the process of “noise-shaping”), so that the noise cannot be heard. In this fashion the noise shaper is able to minimize the audible error of the power amplifier.
Another new aspect of the present invention is the use of a novel switched-capacitor tracking power-supply which does not rely on inductors, and is therefore ideal for integrated-circuit use. Variations in the design of the network of switched-capacitors allow the creation of both positive and negative output voltage to double the dynamic range, and also the creation of an output voltage whose absolute value is higher than that of the power supply voltage to further increase the dynamic range.
FIG. 2 shows a basic switched-capacitor tracking power-supply 104 according to the present invention. A capacitor bank 202 has a number of capacitors, illustrated as capacitors 202 -A, 202 -B, 202 -C, 202 -D, and 202 -E, for storing electrical energy. Any reasonable number of capacitors may be employed. The capacitors do not have to be of the same value. In one embodiment, as shown in FIG. 2, capacitors 202 -A, 202 -B, 202 -C, 202 -D, and 202 -E are connected in common on one side to V ss 102 -B. A V+ selector 204 is connected individually to the other sides of capacitors 202 -A, 202 -B, 202 -C, 202 -D, and 202 -E via lines 205 -A, 205 -B, 205 -C, 205 -D, and 205 -E, respectively. In addition, V dd 102 -A and V ss 102 -B are also inputs to V+ selector 204 . In this manner, V+ selector 204 can selectively connect V dd 102 -A, V ss 102 -B or one side of any one of capacitors 202 -A, 202 -B, 202 -C, 202 -D, or 202 -E to supply voltage terminal V+ 104 -A. Likewise, a V− selector 206 is also connected to the other sides of capacitors 202 -A, 202 -B, 202 -C, 202 -D, and 202 -E via lines 205 -A, 205 -B, 205 -C, 205 -D, and 205 -E, respectively. In addition, V dd 102 -A and V ss 102 -B are also input into V− selector 206 . Thus, V− selector 206 can selectively connected V dd 102 -A, V ss 102 -B or one side of any one of capacitors 202 -A, 202 -B, 202 -C, 202 -D, or 202 -E to supply voltage terminal V− 104 -B. In this specific example the possible voltage that can be generated across V+ and V− terminals include: 0, ±(V dd −V ss ), ±(V dd −V ss -C n ), ±(C n ), ±(C n -C m ), where C n and C m are the voltages on the respective capacitors. A control logic unit 208 controls V+ selector 204 via a control lines 208 -A and V− selector 206 via a control line 208 -B so that V+ selector 204 and V− selector 206 are respectively connected to different input lines (lines 205 -A, 205 -B, 205 -C, 205 -D, 205 -E, V dd 102 -A, and V ss 102 -B) according to the desired output voltages V+ 104 -A and V− 104 -B and the voltages available on capacitors 202 -A, 202 -B, 202 -C, 202 -D, and 202 -E, along with V dd 102 -A, and V ss 102 -B. An optional voltage sensor 210 monitors the voltages on lines 205 -A, 205 -B, 205 -C, 205 -D, and 205 -E, and reports the respective voltages thereon to control unit 208 . An optional current sensor 212 monitors a current I in 216 at voltage V− 104 -B, and reports this current to control logic 208 . Because current I in 216 is equal to a current I out 214 , current sensor 212 could also be located in other positions within the circuit. Note that at any given time, both V+ selector 204 and V− selector 206 are characterized by respective states according to the selection. State information is taken into account by control logic 208 to determine the network connection.
As noted, feedback control via noise shaper 106 around power stage 108 (FIG. 1) serves as a control system to reduce non-linearity, as well as a noise-shaping filter to control the distribution of noise energy across the spectrum. This allows for much greater flexibility for optimizing the previously-cited design factors, since the non-linearity and noise generated in the power stage can be corrected by this feedback control and noise-shaping unit.
Therefore, by employing a switched-capacitor tracking power-supply and a noise shaper, the present invention allows the use of low-cost, high-efficiency power components, while still achieving noise free linear power output regardless of noise and non-linearity which might be inherent in the components.
Discrete Power Stage
Another aspect of the invention uses the tracking power supply itself to drive the power amplifier output directly, rather than acting as a power supply for a linear power stage, thus creating a discrete power stage. As is well-known in the art, pulse-width-modulation (PWM) and class-D (digital) power amplifiers are based on power switches that toggle the output between two voltages. In general, there technologies generates an over-sampled 1-bit signal using a variety of noise shaping and pulse-width-modulation techniques, and then use a power switch as the power stage to drive a load with this 1-bit signal. An amplifier operating according to such principles can be viewed as a one-bit quantizer with noise-shaping. The quantizer generates quantization noise with amplitude of 0.5 bit. That is, at least 0.5 of the energy output by the power stage is noise. For audio applications, noise-shaping techniques ensure that the quantization noise resides above the audio spectrum at inaudible frequencies (typically above 20Khz). Such general techniques are herein denoted by the term “one-bit quantizer”.
There are three major factors causing inefficiency in such one-bit quantizer systems.
The first factor is the energy of the noise itself. Although this noise is inaudible, it is still produced by the output power stage. This energy can be removed from the output signal by filtering, but unless the filter used is a reactive filter, this noise energy will be dissipated as heat. In systems where other than a reactive filter is used, the efficiency is limited.
In systems where a reactive L-C low-pass filter is used, the energy is not wasted, but rather is recycled by the inductors and capacitors. Unfortunately, L-C networks are relatively bulk and generate significant electromagnetic interference (EMI), and thus are not practical to use in many applications, especially portable audio appliances where efficiency is critical.
The other factors that reduce efficiency in such amplifiers a related to imperfections in the power switch. Parasitic capacitance and finite rise and fall times in the power switch cause loss of energy associated with each toggle of the output voltage from one state to another. This loss of energy is proportional to the voltage difference across the switch at the time of the toggle, to the rise/fall times of the switch and to the switching frequency. Most of the energy loss is due to energy dissipation during the rise/fall period of the switch, when the product of the voltage over the switch and the current through it is not close to zero.
Therefore, the high switching frequency associated with one-bit quantizer systems is another factor leading to inefficiency. Due to the excessive amount of noise energy, a high degree of over-sampling to required, and this leads to a high switching frequency.
The fact that the voltage difference at the time of each toggle is extreme, from V ss to V dd , further increases the energy losses. Some prior art techniques address this problem by trying to reduce the number of switching transitions that take place, as is disclosed, for example, in reference [1].
According to the present invention, replacing the one-bit quantizer of current technologies with a Multi-Level Quantizer, can significantly reduce the effects of all of the above factors, and thereby dramatically increase the efficiency of power amplifiers based on switching principles.
The energy of quantization noise output from a Multi-Level Quantizer is proportional to one-half the average difference between levels. Depending on the number of levels in the Multi-Level Quantizer, this noise energy can be significantly less than that of a one-bit quantizer. Furthermore, because there is less noise energy in the signal, the amount of over-sampling required to reach the same noise performance is greatly reduced, and thus the switching frequency and energy losses are reduced. Moreover, because the voltage across each switch during the switching transition time is much smaller for a Multi-Level Quantizer compared with a one-bit quantizer, the average energy loss associated with switching is reduced. (Typically, this is the average voltage difference between two adjacent levels, versus the full range of V dd to V ss ).
In order to implement a Multi-Level Quantizer, it is necessary to generate multiple voltage levels. According to the present invention, an efficient way to generate multiple voltages from one power supply is by using the same network of switched capacitors as in the tracking power-supply previously described. The target function for the control logic in this case is simply to produce the level closest to the signal at the input of the Multi-Level Quantizer. Other constraints can be added in the control logic, as will be described below by way of a non-limiting example regarding the Constrained capacitor or targeted capacitors selection algorithms.
Therefore, according to the present invention thee is provided a power amplifier receiving electrical energy from a primary source of electrical energy having a V ss source voltage and a V dd source voltage, the power amplifier receiving an input signal via input terminals and supplying a power output signal via load terminals, the power amplifier including a network of switched capacitors containing at least one capacitor for storing electrical energy, each of the capacitor having a voltage thereon, wherein the network of switched capacitors is operative to configuring electrical circuits between the load terminals, and wherein the electrical circuits include voltages and components selected from a group containing (a) and V ss source voltage, (b) the V dd source voltage, and (c) a non-negative number of capacitors of the network of switched capacitors.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention block diagram is herein described, by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 shows a general block diagram of a power amplifier according to the present invention.
FIG. 2 shows a general block diagram of a switched-capacitor tracking power-supply according to the present invention.
FIG. 3 shows an example of a state of a switch-capacitor tracking power-supply according to the present invention at a time t 1 .
FIG. 4 shows an example of a state of a switched-capacitor tracking power-supply according to the present invention at a time t 2 subsequent to time t 1 .
FIG. 5 is a block diagram of a switched-capacitor tracking power-supply according to the present invention incorporating a voltage step-up unit.
FIG. 6 shows some non-limiting examples of possible circuits that can be achieved by different network connections in the tracking power-supply according to the present invention.
FIG. 7 shows a capacitor with a versatile selector according to the present invention.
FIG. 8 shows a configuration for the internal step-up of voltage by switching circuits, according to the present invention.
FIG. 9 shows an example of a state of a switched-capacitor tracking power-supply with internal voltage step-up according to the present invention at a time t 3 .
FIG. 10 shows an example of a state of a switched-capacitor tracking power-supply with internal voltage step-up according to the present invention at a time t 4 subsequent to time t 3 .
FIG. 11 shows a block diagram of a discrete power stage power amplifier with analog noise-shaping loop and control logic according to the invention.
FIG. 11A shows a block diagram of a linear power stage power amplifier with analog noise-shaping loop and control logic according to the invention.
FIG. 12 shows a block diagram of a discrete power stage power amplifier with analog noise-shaping loop and digital control logic according to the invention.
FIG. 13 shows block diagram of a discrete power stage power amplifier with digital noise-shaping loop and control logic according to the invention, where the noise-shaping is performed according to an estimation of the output provided by the control logic.
FIG. 13A an interpretation of the block diagram of FIG. 13 as a noise-shaped quantizer with additive noise at the output.
FIG. 14 shows a block diagram of a linear power stage power amplifier with a tracking power supply and no noise-shaping loop according to the invention.
FIG. 15 shows a block diagram of an implementation of an embodiment of the network of switched capacitors according to the invention, suitable for the targeted capacitors selection algorithm.
FIG. 16 shows a block diagram of a more versatile implementation of an embodiment of the network of switched capacitors according to the invention, suitable for the targeted capacitors selection algorithm, and capable of generating 2*N+3 quantization levels.
FIG. 17 shows a block diagram of a more versatile implementation of an embodiment of the network of switched capacitors according to the present invention, suitable for the targeted capacitors selection algorithm, and capable of generating 2 (N+1) quantization levels where output is floating.
FIG. 18 shows an embodiment similar to that of FIG. 17, capable of generating an output that is always referenced to V ss , and where capacitors are floating.
FIG. 19 shows no embodiment similar to that of FIG. 17 and 18, capable of generating an output that is always referenced to V ss , and where a network connection can be made where capacitors are referenced to V ss .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The principles and operation of a power amplifier according to the present invention may be understood with reference to the drawings and the accompanying description.
In some of the following embodiments, the combination of the tracking power-supply, and specifically the type of tracking power-supply described herein, with the feedback control and noise-shaping unit around the power stage is essential. Otherwise the switching noise and common mode noise created by the tracking power-supply can be unacceptable.
Switched-Capacitor Tracking Power-Supply
According to the invention, and as illustrated in FIG. 1 and FIG. 2, tracking power-supply 104 is implemented using one or more capacitors 202 along with the primary power source 102 . The purpose of capacitors 202 is to store electrical energy and act as voltage supply sources. At each instant, capacitors 202 and the primary power source outputs 102 -A and 102 -B form a group of possible voltage supply sources, control logic unit 208 examines the state of the whole system, and periodically selects one of the possible supplies (V dd 102 -A, V ss 102 -B, or one side of any one of capacitors 202 -A, 202 -B, 202 -C, 202 -D, or 202 -E) as the positive supply V+ 104 -A to power stage 108 , and one of the possible supplies (V dd 102 -A, V ss 102 -B or one side of any one of capacitors 202 -A, 202 -B, 202 -C, 202 -D, or 202 -E) as a negative supply V− 104 -B to power stage 108 . No resistors or inductors are used. Depending on the selection made by control logic unit 208 , some of capacitors 202 may be charged or discharged through output load 112 so that there be no loss of energy within tracking power-supply 104 . By applying a selection algorithm, control logic unit 208 can maintain a desired network state.
To illustrate the operation of the switched-capacitor tracking power-supply, assume that at a time t 0 , all of capacitors 202 -A, 202 -B, 202 -C, 202 -D, or 202 -E are discharged, and hence there is initially a voltage equal to V ss 102 -B on lines 205 -A, 205 -B, 205 -C, 205 -D, and 205 -E.
FIG. 3 shows an example of a state of switched-capacitor tracking power-supply 104 at a time t 1 subsequent to time t 0 . In this example, in response to the needs of power stage 108 , control logic unit 208 (FIG. 2) has set V+ selector 204 to select V dd 102 -A to provide V+ 104 -A, and has set V− selector 206 to select capacitor 202 -B on line 205 -B to provide V− 104 -B. This provides an initial instantaneous voltage of V dd -V ss across output load 112 . During the time interval (t, t+Δf) the flow of current I in 214 through V− selector 206 charges capacitor 202 -B gradually. Thus the supply voltage seen by the power stage (that is, V ss -V capacitor ) decreases gradually. Since the energy dissipated in the power stage is proportional to the difference between the supply voltage and the output voltage, the decrease of supply voltage to the power stage actually decreases the energy dissipated in the power stage, and this ‘saved’ energy is stored in capacitor 202 -B.
The flow of current I in 214 through V− selector 206 charges capacitor 202 -B, to recover and store usable energy that is not dissipated by power stage 108 and output load 112 . In the case of the linear power stage, by setting V+ 104 -A and V− 104 -B to be minimally outside the voltages required by power stage 108 , the energy dissipated by power stage 108 will be minimized, and the majority of the energy loss will be confined to output load 112 . The length of time interval Δt that switched-capacitor tracking power-supply 104 remains in this selected state should be small in comparison with the time-constant for charging and discharging the capacitors in order that the voltage across output load 112 remains large enough to satisfy the requirements of power stage 108 . Similarly, in the case of a discrete power stage, by setting V+ 104 -A, and V− 104 -B to be close to the required voltage at the load, the energy of the error can be minimized. Over the duration of time interval Δt, assume that current I in 214 charges capacitor 202 -B to a voltage ΔV so that line 205 -B is at a voltage V ss +ΔV at the end of time interval Δt.
FIG. 4 shows another example of a state of switched-capacitor tracking power-supply 104 at a time t 2 =t 1 +Δt. In this example, in response to the needs of power stage 108 , control logic unit 208 (FIG. 2) has set V+ selector 204 to select capacitor 202 -B on line 205 -B to provide V+ 104 -A, and has set V− selector 206 to select capacitor 202 -A on line 205 -A to provide V− 104 -B. Because capacitor 202 -A is initially discharged, at time t 2 V− 104 -B will be at a voltage V ss .
As discussed above, at time t 2 the voltage on line 205 -B is V ss +ΔV. Assume that switched-capacitor tracking power-supply 104 remains in this selected state also for time interval Δt, during which capacitor 202 -B discharges through power stage 108 by current I out 214 and capacitor 202 -A charges through power stage 108 by current I in 216 (which equals current I out 214 ). The voltage on capacitor 202 -B thus decreases, while the voltage on capacitor 202 -A increases. At the time interval (t+Δt, t+2Δ), thee is already a voltage ΔV across capacitors 202 -B. If the required output at time t+Δt is less than ΔV, capacitor 202 -B is sued as the positive supply, and the less energy will be dissipated in the power state compared with using V dd . As before, capacitor 202 -A will be charged during this time interval, and the supply voltage ‘seen’, by the power stage will decrease during the time interval, thereby also decreasing the energy dissipated, and storing this energy into capacitor 202 -A.
As the demands of power stage 108 change in response to changing requirements to amplify input signal 110 (FIG. 1 ), control logic unit 208 (FIG. 2) will set V+ selector 204 and V− selector 206 to select different capacitors as necessary to meet the requirements, utilizing energy stored in the capacitors.
FIG. 6 illustrates, by way of example, a variety of circuits which can be achieved by different configurations of the capacitors of a tracking power-supply according to the present invention. The examples of FIG. 6 involve up to two capacitors at a time. FIG. 7 shows a capacitor 302 with an upper selector 304 and a lower selector 306 . Using this selector configuration in conjunction with a number of capacitors, many different circuits, such as illustrated in FIG. 6 can be created. Upper selector 340 also has a connection 308 to the ‘sensor +’ and lower selector 306 has a connection 310 to the ‘sensor’. These are for input of the voltage on each capacitor, and serve as information input into control logic unit 208 (FIG. 2 ).
Stepped-Up Supply Voltages
According to another embodiment of the invention, the group of possible voltage supply sources can also include voltage supplies with higher voltages than the main power-supply. Such supplies can be achieved by any of the efficient DC-to-DC ‘step up’ circuits currently known in the art. FIG. 5 shows a switched-capacitor tracking power-supply 504 having a voltage step-up unit 506 fed by V dd supply 102 -A and in turn supplying an increased voltage to V+ selector 204 via a line 508 . In this manner, an increased voltage can be output as V+ 104 -A.
Internal Voltage Step-Up
According to still another embodiment of the invention, it is possible to configure the switched capacitors with additional selection circuitry to create the stepped-up voltages without a separate voltage step-up unit. FIG. 8 illustrates such a configuration, having two additional selectors, a lower selector 602 which selects from the lower terminals of capacitors 202 and an upper selector 604 which selects from the upper terminals of capacitors 202 . In this configuration lower selector 602 and upper selector 604 are controlled by control unit 208 , and a connection line (bus) 606 is provided to allow the upper terminal of a capacitor to be connected to the lower terminal of another capacitor according to the selections of lower selector 602 and upper selector 604 . In this fashion it is possible to cascade capacitors and main supplies in series and thereby add voltage together. FIG. 9 illustrates an example of a state of lower selector 602 at a time t 3 , in which lower selector 602 connects the lower terminals of capacitor 202 -B and capacitor 202 -C to V ss 102 -B. The upper terminals of capacitor 202 -B and capacitor 202 -C are connected via V− selector 206 to provide V− 104 -B and these capacitors are thus charged in parallel to the same voltage by current I in 216 . In this example, upper selector 604 (FIG. 8) does not select any capacitors at time t 3 and is not shown in FIG. 9 . FIG. 10 illustrates a later state of this power supply at a time t 4 =t 3 +Δf, in which the connections of the capacitors are changed by different selections of lower selector 602 and the involvement of upper selector 604 . As shown in FIG. 10, capacitor 202 -B is no longer connected in parallel with capacitor 202 -C, but rather these two capacitors are connected in series via upper selector 604 and line 606 , so that the upper terminal of capacitor 202 -B on line 205 -B to V+ selector 204 has a voltage which is the sum of the voltages of capacitor 202 -B and capacitor 202 -C. Thus, voltage V+ 104 -A is effectively double the voltage to which each capacitor was charged when the parallel charging arrangement was in effect (FIG. 9 ).
Doubling the Output Range by Inversion
As can be seen from the example of FIG. 2, the selectors can create the same absolute voltage difference between the V+ and V− in both polarities simply by interchanging the selections for V+ and V−. In this way, a peak-to-peak voltage of 2*(V dd -C ss ) can be easily generated between the V+ and V− terminals.
Selection Algorithm
The accuracy of the tracking of the tracking power-supply directly affects the resulting efficiency, and thus the instantaneous goal of the selection algorithm is to minimize the target function. On the other hand, because the capacitors are charged and discharged only while selected, longer term considerations should also be applied to guarantee a good network state and the availability of enough choices during future time intervals. Thus, the selection algorithm for selecting the capacitor switching is critical for the resulting efficiency. Efficient selection algorithms may involve knowing the input signal statistics, predicting the input signal, and complex decision strategies. Some selection algorithms for selection are presented below.
Free-Running Capacitor Selection Algorithm
In an embodiment of the present invention, a selection algorithm simply minimizes the target function. This selection algorithm is herein denoted by the term ‘free-running capacitor’. Empirical statistical simulations show that the typical speech as an input signal, the free-running capacitor selection algorithm will yield about 70% efficiency using three capacitors. This is a favorable improvement over the 25% efficiency of a class-AB power amplifier with a similar input signal. In the special case of a single capacitor, this selection algorithm provides to be surprisingly efficient compared with more sophisticated strategies.
Constrained Capacitor Selection Algorithm
In another embodiment of the present invention, a more sophisticated selection algorithm tries to keep the voltages across the capacitors within a predefined range of voltages. This selection algorithm is denoted herein by the term ‘constrained capacitor’. To achieve this target, another condition is imposed, whereby a capacitor can be selected such that the voltage across it will increase only when the that voltage is below the allowed range. Likewise, a capacitor can be selected such that the voltage across it will decrease only when that voltage is above the allowed range. The determination of the voltage ranges for each capacitor is critical for the success of this selection algorithm. Because each capacitor eventually strays within a range, it can be shown that, starting from initial conditions where each capacitor is within range, the average current through this capacitor will be zero, and so will be the average current through all capacitors combined. It can be shown that for this condition to be satisfied while still being efficient, it is required that approximately the same output voltage be generated in at least two ways. One way is such that the overall charge on all capacitors will increase, and another way is such that the overall charge on all capacitors will decrease.
Targeted Capacitor Selection Algorithm
In another embodiment of the present invention, a simplification of the constrained capacitor selection algorithm is to try to keep the voltages across the capacitors sufficiently close to a target voltage. This selection algorithm is herein denoted by the term ‘targeted capacitor’. To achieve this, a condition is imposed on the selection algorithm, whereby a capacitor can be selected such that the voltage across the capacitor will increase only when that voltage is below the target voltage. Likewise, a capacitor can be selected such that the voltage across the capacitor will decrease only when that voltage is above the target voltage.
A convenient property of the targeted capacitors selection algorithm is that in order to implement it, only a 1-bit state per capacitor is needed to be known, indicating whether the voltage on each capacitor is above or below the target voltage. Such a 1-bit state can be generated by comparators that compare the voltage over each capacitor to the respective target voltage.
Estimation of the Average Output Voltage from each Capacitor for the Targeted Capacitors Selection Algorithm
The term ‘target error’, herein denotes the error of the actual average voltage supplied by a capacitor during a load time interval relative to the capacitor's target voltage. A convenient property of the targeted capacitors selection algorithm (detailed above) is that the deviation of each capacitor's voltage from the respective target voltage can be guaranteed not to exceed a predetermined maximum deviation. This is because, over any time interval during which a capacitor discharges, the initial voltage on that capacitor is equal or higher than the respective target voltage, and depending on the network parameters, there is a limit on how much the capacitor can discharge by the end of the time interval. The same applies to any time interval during which a capacitor charges. Thus the voltage over each capacitor will vary around the respective target voltage, and the capacitance, the load impedance, and the switching time intervals can be chosen such that the deviation of the capacitor voltage from the target voltage is guaranteed not to exceed a predetermined maximum deviation. If the voltage over a capacitor is above target, for example by the above-mentioned maximum deviation, then during the next load time interval where this capacitor is used, the capacitor will discharge. Thus, the average voltage supplied by the capacitor over the whole time interval is closer to the target voltage than the above-mentioned maximum deviation. Therefore, the target error is smaller than the maximum deviation, and can be very close to zero if the voltage across the capacitor crosses the value of the target voltage during the load time interval.
Hence, by using the targeted capacitors selection algorithm, the network of switched capacitors can be designed such that a capacitor's target voltage serves as a good estimate of the capacitor's average output voltage. This property is useful in providing a good estimated network state with a simple 1-bit state sensor.
2*N+3 Level Quantizer using N Capacitors and the Targeted Capacitors Selection Algorithm
It can be proven that, using the targeted capacitors selection algorithm where the target voltages for each capacitor are evenly distributed between V dd and V ss ; and where the network of switched capacitors is capable of creating at least the group of voltages 0, ±(V dd -V ss ), ±(V dd -V ss -C n ), ±(V dd -V ss +C n -C m ), ±(C n ), ±(C n -C m ) between the tracking power supply output terminals; then at any given moment it is possible to create any output voltage from the group ±J/(N+1)*(V dd -V ss ) up to the target error, where 0≦J≦N+1, and where N equals the number of capacitors. This provides a behavior similar to that of a quantizer with 2*N+3 quantization levels.
1+2 (N+1) Level Quantizer using N Capacitors and the Targeted Capacitors Selection Algorithm
Using the targeted capacitor selection algorithm where the target voltages for the capacitors are distributed as a series of negative powers of 2 starting from (V dd -V ss )*2 −1 for the first capacitor C 1 , (V dd -V ss )*2 −2 for the second capacitor C 2 , and so on up to (V dd -V ss )*2 −N for the Nth capacitor C N , and where the network of switched capacitors is capable of creating between the tracking power supply output terminals at least any of the following combination of the supplies and capacitors:
±(A 0 *(V dd -V ss )+A 1 *C 1 +A 2 *C 2 +. . . +A N *C N )
Where A 1 , . . . A N are any of −1 or 0 or 1
And where A 0 is either 0 or 1
Than it can be proven that with the above network, and given the restrictions of the targeted capacitor selection algorithm, in all cases any level between —(V dd -V ss ) and (V dd -V ss ), in increments of (V dd -V ss )*2 −N can be created up to the target errors. This is easily proven by observing that any voltage (V dd -V ss )*2 −n can be generated either by using directly the capacitor C n (in which case the capacitor C n will discharge), or by using C (n−1) -C n where n>1, or (V dd -V ss -C 1 ) where n=1 (in which case the capacitor C n will charge). This provides a behavior similar to that of a quantizer N+1 bits. By adding the voltages (V dd -V ss )*2 −n , any level close to ±K*(V dd -V ss )*2 −N can be generated, with an error related to the target error.
Proof:
To simplify, relate to the case where (V dd -V ss )=1, and to the target error as 0. Denote the 1-bit state for the nth capacitor by S n , where S n= 1 means that the voltage across the capacitor is above the target voltage, and where S n =0 means that the voltage is below the target voltage. S 0 stands for the logical 1-bit state of the positive supply V dd , and is by definition always 1 (this manifests the fact that the supply always supplies current to charge the capacitors). First, relating only to positive quantization levels, find the binary representation: K*2 N =B=(B 0 *2 0 +B 1 *2 −N ), where: 0≦K≦2 N , and B 0 . . . B N are 0 or 1. If the 1-bit state of all capacitors allows them to discharge, then generating any such value can be done simply by cascading the capacitors whose corresponding bit B n is 1. For the generic case where the 1-bit states are arbitrary, the following algorithm will find how to generate the desired output while conforming to the targeted capacitors selection algorithm:
For each bit B n , starting from the least significant bit B N to B 0 compute A n recursively as follows:
(1) If (B n =0) then A n =0;
(2) If (B n =1 and S n =1) then A n =1;
(3) If (B n =1 and S n =0) then A n =−1; B=B+2 −n+1 .
At the end of this procedure we will get A 0 to A N as defined above
Where A 1 . . . A N are any of −1, 0, or 1; and where A 0 is either 0 or 1.
The control logic should create a network connection cascading the cascading the capacitors according to their respective coefficients A n . When A n =0 the corresponding capacitor is not used, when A n =1 the corresponding capacitor is cascaded with positive polarity, and when A n =−1 the corresponding capacitor is cascaded with negative polarity. Finally, the sign of the desired output can be applied by connecting the network's output terminals according to the desired polarity. This completes the proof.
Furthermore, it can be shown that the above proof can be generalized such that the same results can be achieved with the target for the capacitor C n being of the more general form M*(V dd -V ss )*2 −n where M is any odd integer.
Target Function
As noted previously, a target function should be provided for determining the output of the tracking power-supply in order that the tracking power-supply be able to accurately track the output requirements. In an embodiment of the present invention that uses a linear power stage, the target function V p is a function of the input signal and the internal input to the power stage, and is given by
V p (input signal, internal input)=maximum((1 +e )×|( K× internal input)|, |( K× internal input)|+ a, b ),
where || denotes taking the absolute value, and:
e is a constant 0<e<<1, that allows a margin for overcoming system gain inaccuracies due to components' inaccuracies and parasitic losses.
a is a constant 0<a, that allows a margin for the minimal voltage difference required by the linear power stage between the output voltage and the supply voltage.
b is a constant 0<b<<1, that allows a margin for overcoming the system's DC offsets.
K is the gain of the power stage.
Noise-Shaping
In an embodiment of the present invention, control logic unit 208 implements noise-shaping such that the output of the power amplifier is given by:
output =K× input signal× FS+E×FN,
where
K is the desired system gain;
FS is a transfer function that is substantially unity in the range 20 Hz-20 Khz;
E is any error introduced to the system between the control logic unit and the final output; and
FN is a transfer function essentially following the auditory hearing threshold.
In another embodiment of the present invention, the transfer function FS is given by the expression: FS = 1 1 + s K 1 + s 2 K 1 K 2 ,
and FN is given by the expression:
FN=s 2 FS,
where 0<K 1 and 0<K 2 .
The purpose of such transfer functions is to minimize the audibility of the noise in the output. Therefore, suitable transfer functions should be selected according to human auditory response, using a human auditory sensitivity filter. Other possible implementations of noise shaping both for the digital and analog domain can be found in reference [3].
Predictive Control
A selection algorithm can consider predicted values when determining a network connection. This is especially applicable to power amplification of recorded audio, or where a delay line can be inserted before the power stage and so future values of the input signal can be exactly determined. Even for non-recorded audio, it is often possible to apply a predictive algorithm for the input signal. If a prediction can be obtained for the input signal, it is then possible to obtain a prediction of the internal input to the power stage.
Analog/Digital Implementation of the Noise-Shaping Loop and Control Logic
There are several options for implementing the noise-shaping loop and control logic. The different implementations involving the digital domain, analog domain, and analog-digital mixed-signal hybrids, are covered in detail below.
Fully-Analog Implementation of the Noise-Shaping Loop and Control Logic
FIG. 11 illustrates a fully-analog implementation of the noise-shaping loop and control logic according to an embodiment of the present invention. Analog implementations of the noise-shaping loop are known in the art. For example, similar techniques to those used in sigma-delta modulators are appropriate to use in embodiments of the present invention. These techniques use a negative feedback and integrators. Higher order sigma-delta networks can be implemented as well, depending on the kind of noise-shaping loop needed.
In such an implementation, the inputs to a noise shaping unit 111 are an analog input 111 A and an analog feedback 111 C taken through a differential buffer 111 D from power stage output terminals 116 .
To implement a control logic unit 117 in the analog domain, the value of the target function for different network connections must be computed, and the network connection corresponding to the minimum value should be chosen. Control logic unit 117 receives a sensor input 113 from a network of switched capacitors 115 , and sends a control signal 114 thereto. Different network connections can be created with the sensor instead of the load terminals. Those skilled in the art can readily see that computing the value of the target function can be done using analog adders. The minimum value can be stored in an analog sample-and-hold component, and can be compared against new ‘candidate’ values using analog comparators.
FIG. 11A shows another embodiment according to the invention which is the equivalent of the embodiment of FIG. 11, for the case of a linear power stage. Here the outputs 116 B of network of switched capacitors 115 are used as the power supply for a linear power stage 116 , and the load is connected to an output 116 C of linear power stage 116 . An input 116 A to power stage 116 is taken from an output 11 B of noise shaper 111 .
Analog Noise-Shaping Loop and Digital Control Logic
FIG. 12 illustrates an embodiment according to the invention, with an analog noise shaper 121 having an input 121 A and a digital domain control logic unit 127 . An output 121 B of a noise shaper 121 is transferred to control logic 127 through an A-to-D converter 122 A via a line 121 C. A network of switched capacitors 125 receives control from control logic 127 via a control line 124 . The resolution of A-to-D converter 122 A needs to be of the same order as that of network of switched capacitors 125 . For example, a 4-bit flash A-to-D will suffice for many practical cases. Also sensor 123 is connected to control logic 127 through an A-to-D converter that may be a low resolution flash A-to-D or may be a 1-bit state, as in the case of the targeted capacitors selection algorithm.
The equivalent of this embodiment for the case of a linear power stage can be easily derived in a way similar to FIG. 11 and FIG. 11 A.
Fully-Digital Implementation of the Noise-Shaping Loop and Control Logic
FIG. 13 illustrates an embodiment according to the invention with a digital noise-shaping loop and control logic, containing a noise-shaping unit 131 having a signal input 131 A, an output 131 B, and a feedback input 131 C; and a control logic unit 132 with a sensor input 133 from a network of switched capacitors 135 and a control 134 to network 135 . Network 135 has an output 136 . If the network state is known in the digital domain through sensor 133 , it is possible to implement the noise-shaping loop and control logic completely in the digital domain. The network state can be monitored via sensor 133 such as an A-to-D converter or the 1-bit state sensors described for the case of targeted capacitors selection algorithm. After performing the selection algorithm, control logic 132 outputs the result in terms of controls to network 135 , while at the same time control logic 132 can feed the estimated output in the digital domain back to the noise-shaping loop. The input to the control logic comes from the noise-shaping loop in the digital domain.
In this embodiment the noise shaping is done via an estimation of the final output, and not via a feedback of the actual final output (output 136 ), and thus the system is working in an open loop with regard to (final) output 136 . It can be shown that the error in estimating the final output is manifest as additive noise at (final) output 136 . As explained previously, for example, with regard to the targeted capacitor selection algorithm, this error can be kept small enough. FIG. 13A shows an equivalent representation of the system of FIG. 13, where the noise shaping is done with respect to feedback from the control logic rather than the actual output and the estimation error is manifest as additive error at the output.
FIG. 14 shows an embodiment of the present invention with a linear power stage 146 and no noise shaping loop. In this embodiment the supplies for linear power stage 146 are provided by an output 146 B from a network of switched capacitors 145 . An input signal 141 A feeds an A-to-D converter 141 having an output 141 B into a control logic unit 142 which controls network 145 through a control line 144 . Control logic unit 142 receives state information from network 145 through a sensor 143 . Linear power stage 146 also receives input signal 141 A through a line 146 A. The final load is connected to an output 146 C of linear power stage 146 via terminals 146 C. The switching noise and transients from network 145 to power stage 146 are reduced due to the inherent power-supply-reduction-ratio (PSRR) of linear power stage 146 . In this embodiment, the network of switched capacitors is simply used as a quantized tracking power supply.
Network State Estimation
In several embodiments according to the present invention, the network state is estimated by measuring voltages across capacitors through the sensor. This measurement can be done, for example, using a simple 1-bit state as described for the case of targeted capacitors, or using an A-to-D converter. In other embodiments, a goal is to minimize the amount of information sampled through the A-to-D converter. Since not all capacitors change voltage during every time interval, it is sufficient to monitor and update the state of each capacitor only when there is an actual change. Furthermore, it is also possible to monitor the state of each capacitor only once every few changes. Between monitoring operations, the state of the capacitor can be estimated. During such times that the capacitor's state is estimated, the control logic operates according to the estimated network state. Estimates may be based on knowledge of network parameters such as the primary power supplies, the capacitance of each capacitor, the impedance of the output load, and the length of time during which the capacitor was used.
Network parameters may either be supplied to the control logic by the user, or may be measured and estimated by the control logic. To do this, the control logic can create a desired network connection with known initial conditions, and monitor the final conditions after some time interval. This can be done during a dedicated initialization time and/or during operation.
Embodiments of the Network of Switched Capacitors
Several different embodiments of the network of switched capacitors are described below. These embodiments are described by way of non limiting examples, and differ in one or more of the following characteristics:
Complexity of the network of switches and capacitors;
Number of switches;
Number of possible output levels;
Whether the voltage at the output terminals is floating or referenced (to V ss or V dd ); and
The implementation of the sensor.
Any of these embodiments can serve as the network of switched capacitors according to this invention. Specifically, they can be used in conjunction with the embodiments described above and illustrated in FIGS. 11 to 14 .
FIG. 15 shows an embodiment of the network of switched capacitors according to the present invention. The network includes capacitors 152 A, 152 B, 152 C, and 152 D, all of which share a common connection 152 which is at voltage V ss 150 B. The other sides of the capacitors are connected to comparators 151 A, 151 B, 151 C, and 151 D, respectively, and the other inputs to the comparators are at various points in a resistor voltage divider network as shown, which is connected from V ss 150 B to a voltage V dd 150 A. A load output L+ 154 A and a load output L− 154 B are selected by a switch 153 A and a switch 153 B, respectively.
The embodiment illustrated in FIG. 15 uses several techniques to simplify implementation of a power amplifier according to the present invention. These techniques include:
Applying the targeted capacitor selection algorithm.
Using the 1-bit state from comparators 151 A-D by the control logic as an input to the selection algorithm.
Using the 1-bit state from comparators 151 A-D to estimate the voltage over each capacitor, for use by the control logic and possibly also by the noise shaping loop.
Implementing the targeted capacitors selection algorithm is simple, because only a 1- bit state value is needed to represent whether the capacitor's voltage is above or below the target voltage. This 1-bit state can be derived easily in the analog domain for example by using the comparators, where the target voltage is created by using the resistor network, or any other suitable arrangement. This 1-bit state can be directly available for use in the digital domain.
As explained above, a corollary of the targeted capacitor selection algorithm is that the target voltage for a capacitor is a good estimate of the average output voltage from the capacitor.
Given the estimated voltages on each capacitor, the control logic can select the best possible configuration of switches, subject to the restrictions of the selection algorithm. Once the selection is made, the control logic can also compute the estimated output voltage across the output terminals, using the same estimated voltages on each capacitor. This estimated output voltage can then be used in the digital domain by the noise-shaping loop. The error resulting from performing noise shaping according to an estimated output voltage rather than the exact output voltage can be shown to be an additive error whose magnitude is related to the target error.
As previously noted, in the embodiment illustrated in FIG. 15 one side of four capacitors 152 A-D is permanently connected through 152 to Vss 150 B. The other terminal of each capacitor is connected to one terminal of one of the comparators 151 A-D respectively, and to two switches, one switch from the group 153 A- 1 through 153 A- 6 and one switch from the group 153 B- 1 through 153 B- 6 that are connected to the output terminals 154 A and 154 B respectively. The other terminal of each of the comparators 151 A-D is connected to a reference target voltage generated by a network of resistors between V dd 150 A and V ss 150 B. The comparators compare the voltage over each capacitor to the respective target voltage, and thus the output from each comparator 151 A-D is a 1-bit state. This 1-bit states forms the sensor which is the input to the control logic, such as sensor 143 to control logic unit 142 (FIG. 14 ). Each of the load terminals 154 A and 154 B is connected through a group of 6 switches 153 A- 1 to 153 A- 6 and 153 B- 1 to 153 B- 6 respectively, to the group of 6 sources including V dd 150 A, V ss 150 B and the side of each capacitor 152 A- 152 D that is not connected in common. By controlling the 12 switches, different circuits can be created between the output terminals. It is to be noted that the connections of the output terminals 154 A and 154 B are identical, and thus any circuit can be created between the output terminals in both polarities. The different voltages that can be generated by the network of FIG. 15 between the output terminals are thus: 0, ±(V dd -V ss ), ±C n , ±(V dd -V ss -C n ), ±(C n -C m ). For example, connecting the switches 153 A- 6 and 153 B- 6 can generate a voltage difference of 0 at the output terminals 154 A and 154 B. A voltage difference of (C 4 -C 2 ) can be generated by connecting the switches 153 A- 4 and 153 B- 2 . A voltage difference of (V dd -V ss -C 1 ), can be generated by connecting the switches 153 A- 5 and 153 B- 1 .
One advantage of the network of FIG. 15 is simplicity. The capacitors are always referenced to Vss, and thus it is straightforward to use comparators and compare their voltages to their respective target voltages. Also, the number of switches is relatively small, 2*(2+N) where N is the number of capacitors used.
A disadvantage of the network of FIG. 15 is that only a relatively small number of possible circuits can be generated, and each circuit can involve at most only 2 capacitors.
Recalling the case of the 2*N+3 level quantizer as described above, it is to be noted that the network illustrated in FIG. 15 cannot generate ±(V dd -V ss -C n +C m ). As a result, the error generated by this network relative to the target function is not bounded by ±0.5* (V dd -V ss )/(N+1), and from time to time a bigger error is generated.
It is also to be noted that the voltage difference between the output terminals is floating, and is not always referenced to V ss or V dd . When working with a linear power stage, this can cause transients when the reference at the load terminals changes, and this factor adds noise that must be handled by the noise shaping loop.
FIG. 16 shows a similar embodiment of the network of switched capacitors, where one side of capacitors 162 A, 162 -B, 162 C, and 162 D is connected together at a point 162 , but point 162 is not connected permanently to Vss 160 B. A group of switches 165 - 1 through 165 - 5 is added, that can connect to Vss 160 B, any one of: the common side of the capacitors 162 A, 162 -B, 162 C, and 162 D, or the non-common side of a capacitor. This network is capable of also generating ±(V dd -V ss -C n +C m ). For example (V dd -V ss -C 1 +C 2 ) can be generated by connecting switches 165 - 3 , 163 A- 2 and 163 B- 1 . Thus, this network is capable of implementing the 2*N+3 level quantizer described above. With this network, the error generated relative to the target function is bounded by ±0.5* (V dd -V ss )/(N+1).
Generating the 1-Bit State with Floating Capacitors
In order to achieve the greater connection flexibility of the network illustrated in FIG. 16, the capacitors are not permanently connected to V ss , and are thus floating. Comparing a floating voltage is more complex than comparing a referenced voltage and there are several alternatives to perform this task. One alternative is to use an additional buffer which is a true floating differential buffer, around each capacitor to extract the voltage thereon and feed that voltage to the comparator, in a way similar to that shown in FIG. 18 . Such buffers are more complex and expensive to make, especially in an ASIC environment.
An alternative method, suitable for the network of FIG. 16 as illustrated, is for the control logic to utilize the 1-bit state output of the comparators only during a monitoring time interval. In the case of FIG. 16, a monitoring time interval takes place whenever the common side of the capacitors 162 is connected to Vss through the switch 165 - 1 . One way to achieve this is by a dedicated, short duration, monitoring time interval that is not a load time interval, during which the switch 165 - 1 is closed and all the load switches 163 A and 163 B are disconnected.
Another way to achieve this is without using a dedicated monitoring time interval, but rather whenever a load time interval happens to also be a monitoring time interval. Because the control logic is aware of the network connection at any moment, it can be known, at any time interval, whether that time interval is suitable for monitoring or not (that is, whether is the switch 165 - 1 closed or not). Although a monitoring time interval does not take place during a load time interval, a monitoring time interval takes place from time to time as a consequence of the selection algorithm. Because the control logic is aware of this fact, it is possible to monitor the 1-bit state of the comparators. It is to be noted that with the circuit of FIG. 16, once a monitoring time interval takes place, the 1-bit state of all capacitors can be monitored at once. At load time intervals between two monitoring time intervals, the state of each capacitor can be estimated according to knowledge of the network parameters. In the case of targeted capacitors selection algorithm, the best estimate of the 1-bit state of a capacitor is that the 1-bit state toggles after each time interval during which the capacitor is used.
Implementation of an 1+2 (N+1) Level Quantizer Network using N Capacitors and the Targeted Capacitors Selection Algorithm
FIG. 17 shows an embodiment of a network of switched capacitors that is capable of implementing the network connections needed to fully support the 1+2 (N+1) level quantizer case described above. In this network, a top capacitor 172 has a target voltage (V dd -V ss )*2 −1 and one side of this capacitor is permanently connected to V ss . The other two capacitors have target voltages (V dd -V ss )*2 −2 and (V dd -V ss )*2 −3 , respectively. In this network the voltage at load terminals 173 and 174 is floating, and not all the 1-bit states are available for monitoring at all times. The 1-bit state from a comparator 171 B can be measured only when a switch 172 - 8 is closed. The 1-bit state from comparator 171 C can be measured only when both switches 172 - 8 and 172 - 4 are closed. These conditions specify a monitoring time interval, which can be treated according to one of the methods described above. As before, a resistor voltage-divider network extends from a voltage V dd 170 A to a voltage V ss 170 B. Voltage V dd 170 A and voltage V ss 170 B, in addition to a voltage 172 A, a voltage 172 B, and a voltage 172 C, are input to switches 173 and 174 .
In order to be able to monitor all the 1-bit states at any time, the comparators 171 B and 171 C can be connected to their respective capacitors through a floating differential buffer, similar to the case of FIG. 18, described below.
FIG. 18 illustrates yet another embodiment of a network that is capable of implementing the 1+2 (N+1) level quantizer. Here, the top capacitor has a target voltage (V dd -V ss )*2 −1 , and one side of this capacitor is permanently connected to V dd . This network allows for the voltage at the load terminals to be always referenced to V ss . All capacitors are floating, and therefore must be connected to the comparators via differential buffers, as illustrated.
In FIG. 19, two switches 192 A and 192 B are added, which allow connecting the top capacitor either to V dd or to V ss . The voltage at load terminals 193 and 194 is always referenced to V ss . Switches 192 A and 192 B permit periodically connecting one side of all capacitors to V ss for monitoring, and avoids the need for differential buffers to monitor the capacitors.
Implementation of the Control Logic
An embodiment of control logic suitable for the embodiments of the present invention illustrated in FIGS. 17-19 is described here by way of a non-limiting example. All these embodiments implement the targeted capacitors selection algorithm, and use a 1-bit state to describe the state of each capacitor. The control logic is also aware of the target voltage of each capacitor, for example by their order. The control logic relates to the network of switched capacitors as a quantizer with 2 (N+1) quantization levels, capable of producing an output voltage of the form ±K*(V dd -V ss )/(2 (N+1) ). Thus, the first action performed by the control logic is to determine which of the possible quantization levels minimizes the target function. The second action is to determine the network connection that will give rise to this quantization level, while conforming to the targeted capacitor selection algorithm, given the 1-bit state of each capacitor. Two possible implementations of this second action are given here as non-limiting examples. The first possibility is to perform, in real time, the algorithm described in the 2 (N+1) level quantizer proof, as detailed previously. The second possibility is to use a pre-computed lookup table. Taking the N+1 bit binary representation of the quantization level found in step one above, and concatenating thereto the N 1-bit states from all capacitors will result in a 2*N+1 bit integer. This integer can be used to index a lookup table, where, at each entry of the lookup table is the pre-computed A n parameters described previously, corresponding to the respective quantization level and 1-bit states.
Network State Initialization
In general, the initial conditions of the network state will not be those of the steady state. For example, in the case of targeted capacitors selection algorithm, the initial voltage on each capacitor may be far from the target voltage. In the case of the targeted capacitors selection algorithm, after a short time the network of switched capacitors will reach steady-state, where the voltage over each capacitor is close to the respective target voltage. During this short time the target error will be much larger than during the steady state. For example, if all capacitors are initially completely discharged, the targeted capacitors selection algorithm will only let the capacitors charge until they reach their target voltage. In cases where this initial short time must be minimized, it is possible to pre-charge the capacitors to some good initial conditions.
While the invention has been described with respect to a limited number of embodiments, it will be appreciated that many variations, modifications and other applications of the invention may be made. | A high-efficiency audio power amplifier featuring a tracking power-supply and an active noise shaping unit for reducing non-linearly and audible noise. Several variations of an non-inductive switched-capacitor tracking power-supply are presented, which are well-suited to integrated-circuit implementation and battery operation, and which provide an efficient power supply for the output stage over a wide range of voltages that can exceed the voltage limits of the main power source. The output of the tracking power-supply can be fed into an analog power stage, or can be used as a Multi-Level Quantizer for generating the output directly. A feedback and noise shaping allows the use of low-cost components while relaxing design constraints. Some simple switching strategies are disclosed which offer power efficiencies in excess of 80%. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to a method for distributing banks in a semiconductor memory device, in which individual cells are efficiently grouped into the banks, and more particularly to a bank distribution method for dividing each cell array vertically and horizontally into a plurality of banks and minimizing the length of a data bus to make a high-speed operation of the semiconductor memory device possible.
2. Description of the Prior Art
Generally, a group of cells individually accessed in a semiconductor memory device is called a bank. A very large scale integrated memory device requires a plurality of banks because the performance is enhanced by a bank-interleaved operation.
For example, a 16-Mbit (megabit) dynamic random access memory (DRAM) requires two banks, a 64-Mbit DRAM requires four banks, a 256-Mbit DRAM requires eight or sixteen banks, and a 1-Gbit (gigabit) DRAM requires thirty-two or more banks.
The distribution of banks is performed for the improvement in operation speed of a semiconductor memory device. This is due to the fact that the operation speed of the semiconductor memory device is much lower than that of a microprocessor, resulting in a degradation in the entire system performance. As a result, in order to meet high speed and high bandwidth requirements of the semiconductor memory device, a plurality of banks must be provided in the memory device. Such a conventional bank distribution method for the semiconductor memory device will hereinafter be described with reference to FIG. 1 .
FIG. 1 is a view illustrating a distributed bank configuration of a conventional semiconductor memory device. As shown in this drawing, the conventional semiconductor memory device comprises a plurality of banks (for example, four banks 0 - 3 ), each of which is provided with two bank sections, or left and right bank sections, corresponding respectively to cell arrays. A column decoder is connected to each of the left and right bank sections, and a row decoder is positioned between the left and right bank sections and connected in common to them.
A data bus is provided with N (natural number) data bus lines for transferring data from the banks 0 - 3 to N input/output pads, respectively.
However, in the above-mentioned conventional semiconductor memory device, the length of the data bus is extremely long because it transfers data from all the banks 0 - 3 to the N input/output pads, resulting in a delay in data output. Such a data output delay makes a high-speed operation of the semiconductor memory device impossible.
Further, the bank implementation requires the same number of row decoders and row control signals as that of the banks, resulting in a significant increase in chip area.
SUMMARY OF THE INVENTION
Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a method for distributing banks in a semiconductor memory device, in which each cell array is vertically and horizontally divided into a plurality of banks, resulting in a significant reduction in chip area as compared with a conventional bank distribution method. This method also allows a data bus to be minimized in length because it is localized to each cell array, so that high-speed operation of a semiconductor memory device is possible.
In accordance with one aspect of the present invention, there is provided a method for distributing banks in a semiconductor memory device, the banks being 2 X+Y in number, the semiconductor memory device having a 2 A -bit capacity and including 2 A−B−1 cell array blocks, each including two 2 B -bit cell arrays, a plurality of column decoders connected respectively to the cell arrays, and a plurality of row decoders, each being positioned between the two cell arrays in each of the cell array blocks and connected in common to them, the method comprising a first step of dividing each of the 2 B -bit cell arrays horizontally by 2 X and vertically by 2 Y into 2 X+Y cell groups in such a manner that 2 B−X−Y cells are allocated to each of the 2 X+Y cell groups; and a second step of defining each of the 2 X+Y cell groups as a bank section of a corresponding one of the 2 X+Y banks, where A, B, X and Y are natural numbers.
In accordance with another aspect of the present invention, there is provided a method for distributing banks in a semiconductor memory device, the banks being 2 X+Y−P in number, the semiconductor memory device having a 2 A -bit capacity and including 2 A−B−1 cell array blocks, each including two 2 B -bit cell arrays, a plurality of column decoders connected respectively to the cell arrays, and a plurality of row decoders, each being positioned between the two cell arrays in each of the cell array blocks and connected in common to them, the method comprising a first step of dividing each of the 2 B -bit cell arrays horizontally by 2 X and vertically by 2 Y into 2 X+Y cell groups in such a manner that 2 B−X−Y cells are allocated to each of the 2 X+Y cell groups; and a second step of defining every 2 P of the 2 X+Y cell groups as bank sections of a corresponding one of the 2 X+Y−P banks, where A, B, P, X and Y are natural numbers.
In accordance with still another aspect of the present invention, there is provided a method for distributing banks in a semiconductor memory device, the banks being 2 X+Y+1 in number, the semiconductor memory device having a 2 A -bit capacity and including 2 A−B−1 cell array blocks, each including two 2 B -bit cell arrays, a plurality of column decoders connected respectively to the cell arrays, and a plurality of row decoders, each being positioned between the two cell arrays in each of the cell array blocks and connected in common to them, the method comprising a first step of dividing each of the 2 B -bit cell arrays horizontally by 2 X and vertically by 2 Y into 2 X+Y cell groups in such a manner that 2 B−X−Y cells are allocated to each of the 2 X+Y cell groups; and a second step of defining each of the 2 X+Y+1 cell groups in each of the cell array blocks as a bank section of a corresponding one of the 2 X+Y+1 banks, where A, B, X and Y are natural numbers.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a view illustrating a distributed bank configuration of a conventional semiconductor memory device;
FIG. 2 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a first embodiment of the present invention;
FIG. 3 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a second embodiment of the present invention;
FIG. 4 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a third embodiment of the present invention;
FIG. 5 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a fourth embodiment of the present invention;
FIG. 6A is a view illustrating vertical and horizontal bank selection signals which are used in the present invention; and
FIG. 6B is a circuit diagram illustrating the construction of a bank enable signal generator in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 2 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a first embodiment of the present invention. As shown in this drawing, the semiconductor memory device comprises a plurality of cell array blocks (for example, four cell array blocks), each of which is provided with two cell arrays. Each of the cell arrays is divided vertically by 2 and horizontally by 2 into four groups of cells, each of which constitutes one bank section. A column decoder is connected to each of the cell arrays, and a row decoder is positioned between the two cell arrays in each of the cell array blocks and connected in common to them.
The semiconductor memory device also comprises a plurality of banks (for example, four banks 0 - 3 ), each of which is provided with eight bank sections corresponding respectively to the cell arrays. For example, the bank 0 , indicated by the slash lines in the drawing, includes eight bank sections which are distributed respectively in all the cell arrays.
When any one of the four banks 0 - 3 is accessed, data from the eight bank sections of the corresponding bank are outputted at the same time, resulting in an increase in output speed.
A data bus is provided corresponding to each of the cell arrays and includes N/8 data bus lines. As a result, the data bus is minimized in length.
In the case where the semiconductor memory device has a 2 A -bit capacity and includes 2 A−B−1 cell array blocks, each including two 2 B -bit cell arrays, a plurality of column decoders connected respectively to the cell arrays, and a plurality of row decoders, each being positioned between the two cell arrays in each of the cell array blocks and connected in common to them (where, A and B are natural numbers and 2 A signifies the number of cells in the memory device), each of the 2 B -bit cell arrays is divided horizontally by 2 X and vertically by 2 Y into 2 X+Y cell groups, each including 2 B−X−Y cells, where X and Y are natural numbers. Then, each of the 2 X+Y cell groups is defined as a bank section of a corresponding one of 2 X+Y banks.
In other words, the semiconductor memory device comprises 2 X+Y banks, each of which has a 2 A−X−Y -bit capacity. Each of the 2 X+Y banks includes 2 B−X−Y -bit cell groups, or bank sections, distributed respectively in all the cell arrays.
For example, in a 16-Mbit DRAM, 2 A is 2 24 and 2 B is 2 21 when each cell array has a 16-Mbit capacity. In this case, the number of cell array blocks is 2 24−21−1 , or 4.
Also, in the case where N (natural number) data are to be simultaneously accessed from the 2 B−X−Y -bit bank sections of one bank distributed respectively in all the cell arrays, 2 A−B data buses, each including an n/2 A−B -bit capacity, must be designed in the memory device to transfer the N data to input/output pads. Namely, all the data buses can transfer N bits to the data input/output pads at the same time.
FIG. 3 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a second embodiment of the present invention. As shown in this drawing, the second embodiment of the present invention is the same in construction as the first embodiment in FIG. 2, with the exception that each of the cell arrays is divided vertically by 4 and horizontally by 4 into sixteen groups of cells, each of which constitutes one bank section, and each of sixteen banks 0 - 15 is provided with eight bank sections corresponding respectively to the cell arrays. Similar to the first embodiment in FIG. 2, a data bus with an N/8-bit capacity is localized to each cell array.
The second embodiment in FIG. 3 can be expressed in the same algorithm as that of the first embodiment in FIG. 2 .
FIG. 4 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a third embodiment of the present invention. As shown in this drawing, each of the cell arrays is divided vertically by 4 and horizontally by 4 into sixteen groups of cells, every two of which constitute two bank sections of one bank, and each of eight banks 0 - 7 is provided with sixteen bank sections, every two of which correspond to each of the cell arrays.
In the case where the semiconductor memory device has a 2 A -bit capacity and includes 2 A−B−1 cell array blocks, each including two 2 B -bit cell arrays, a plurality of column decoders connected respectively to the cell arrays, and a plurality of row decoders, each being positioned between the two cell arrays in each of the cell array blocks and connected in common to them (where, A and B are natural numbers), each of the 2 B -bit cell arrays is divided horizontally by 2 X and vertically by 2 Y into 2 X+Y cell groups, each including 2 B−X−Y cells, where X and Y are natural numbers. Then, every 2 P of the 2 X+Y cell groups are defined as bank sections of a corresponding one of 2 X+Y−P banks, where P is a natural number.
Similar to the first embodiment in FIG. 2, a data bus with an N/8-bit capacity is localized to each cell array.
FIG. 5 is a view illustrating a distributed bank configuration of a semiconductor memory device in accordance with a fourth embodiment of the present invention. As shown in this drawing, the semiconductor memory device comprises a plurality of cell array blocks (for example, four cell array blocks), each of which is provided with two cell arrays. Each of the cell arrays is divided vertically by 2 and horizontally by 4 into eight groups of cells, each of which constitutes one bank section. A column decoder is connected to each of the cell arrays, and a row decoder is positioned between the two cell arrays in each of the cell array blocks and connected in common to them.
The semiconductor memory device further comprises a plurality of banks (for example, sixteen banks 0 - 15 ), each of which is provided with four bank sections corresponding respectively to the cell array blocks.
In the case where the semiconductor memory device has a 2 A -bit capacity and includes 2 A−B−1 cell array blocks, each including two 2 B -bit cell arrays, a plurality of column decoders connected respectively to the cell arrays, and a plurality of row decoders, each being positioned between the two cell arrays in each of the cell array blocks and connected in common to them (where, A and B are natural numbers), each of the 2 B -bit cell arrays is divided horizontally by 2 X and vertically by 2 Y into 2 X+Y cell groups, each including 2 B−X−Y cells, where X and Y are natural numbers. Then, each of the 2 X+Y+1 cell groups in each of the cell array blocks is defined as a bank section of a corresponding one of 2 X+Y+1 banks.
In this manner, the plurality of banks are provided in the semiconductor memory device, so that the chip area can be increased minimally.
Also, in the case where N (natural number) data are to be simultaneously accessed from the 2 B−X−Y -bit bank sections of one bank distributed respectively in all the cell array blocks, 2 A−B−1 data buses, each including an N/2 A−B−1 -bit capacity, must be designed in the memory device to transfer the N data to input/output pads. Namely, all the data buses can transfer N bits to the data input/output pads at the same time.
FIG. 6A is a view illustrating vertical and horizontal bank selection signals VBS and HBS which are used in the present invention and FIG. 6B is a circuit diagram illustrating the construction of a bank enable signal generator in accordance with the present invention.
Word lines and bit line sense amplifiers in each bank must be driven independent of those in other banks. For this reason, a bank enable signal is necessary for each bank. In the case where each cell array is divided horizontally by 2 X and vertically by 2 Y into 2 X+Y bank sections, X+Y bank selection addresses (a part of row addresses) must be decoded to generate the horizontal and vertical bank selection signals HBS and VBS. In the bank enable signal generator, a NAND gate NANDs the horizontal and vertical bank selection signals HBS and VBS, and an inverter inverts an output signal from the NAND gate and outputs the inverted signal as the bank enable signal. Namely, the bank enable signal generator performs an AND operation with respect to the horizontal and vertical bank selection signals HBS and VBS to generate the bank enable signal.
The bank enable signal is used to make word line decoders and bit line sense amplifiers in the corresponding bank active, independently of those in other banks.
Although not shown, circuits for generating the horizontal and vertical bank selection signals HBS and VBS can be implemented simply by using a NAND gate and an inverter, as in a row decoder. In FIG. 6B, the horizontal and vertical bank selection signals HBS and VBS can be expressed as follows:
horizontal bank selection signal=HBSi, 1≦i≦2 X
vertical bank selection signal=VBSj, 1≦j≦2 Y .
As is apparent from the above description, according to the present invention, each of the cell arrays is vertically and horizontally divided into a plurality of banks, resulting in a significant reduction in chip area as compared with a conventional bank distribution method. Further, the data bus is minimized in length because it is localized to each cell array. Therefore, high-speed operation of a semiconductor memory device is possible.
Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. | A semiconductor memory device has a plurality of memory cell arrays with a plurality of bank sections. Bank sections identified by different sequence numbers are operated independently of each other. A plurality of data bus lines transfer data in order to write into a desired bank section in each of the memory cell arrays and to read data from the desired bank section in each of the memory cell arrays. The desired bank sections with a same sequence number in each of memory cell arrays are selected simultaneously by a vertical and horizontal bank selection signal. | 6 |
BACKGROUND
[0001] The invention relates to an artificial turf mat, comprising a backing and a number of protruding artificial grass blades divided into rows and connected thereto. Such an artificial turf mat is generally known and is used to form artificial turf fields on which for instance sports, and in particular ball sports, are played. The artificial turf fields are herein formed by laying artificial turf mats on a flat, generally slightly resilient ground and then spreading a layer of loose filling material, for instance sand or a mixture of sand and rubber granules, over these artificial turf mats. The layer of filling material herein has a thickness such that the artificial grass blades protrude thereabove, so that the artificial turf field creates the same impression as a natural grass field.
[0002] Known artificial turf mats have the drawback however that, as a result of the manner in which they are manufactured, the artificial grass blades in a row stand relatively close to each other, while the mutual distance between the rows is often considerably larger. This has the consequence that an artificial turf field on the basis of such an artificial turf mat will display different properties in different directions. In ball sports this can result in a ball not rolling uniformly over the field. Owing to this irregularity the chance of injury, for instance as a result of performing a sliding tackle, is also relatively great when such a sliding tackle is made in the direction of the rows. Tight packing of the blades in a row has the further result that the filling material is there held fast more firmly than between the rows, whereby local compaction and thereby hardening of the field can occur.
SUMMARY
[0003] The invention therefore has for its object to provide an artificial turf mat of the above described type wherein these drawbacks do not occur. This is achieved according to the invention in that the mutual distance between successive blades in a row is substantially equal to the distance between adjacent rows and amounts to at least 10 mm.
[0004] The distance between the blades and the row spacing preferably amounts to at least 13 mm, and more preferably to at least 16 mm. Owing to such a large gap between the individual blades the filling material can be readily loosened periodically, whereby compression or compaction thereof is avoided. The risk of injury as a result of for instance studs getting caught in the artificial turf mat, or a relatively high rotational resistance thereof, is also reduced by this large interspacing.
[0005] The backing and the blades can be formed and mutually connected by weaving. It is however recommended for reasons of production cost that the backing is a fabric and the blades are connected thereto by tufting.
[0006] The blades are advantageously formed from a continuous fibre. This greatly simplifies production of the artificial turf mat.
[0007] In order in this case to ensure an adequate connection of the blades to the backing despite the relatively large interspacing between the blades, at least one support loop protruding less far from the backing is preferably formed in each case between successive blades. For production engineering purposes it is recommended here that the support loops are formed outside the row of blades. The support loops can even be formed from another fibre material than the blades.
[0008] The blades and/or the support loops are preferably formed from a relatively thick and/or heavy fibre material. By making use of a fibre material, for instance a yarn with a high yarn weight (Dtex number) or a large yarn volume, optionally built up from a bundle of different yarns, a well covered mat can be obtained which provides a natural (green) appearance. An additional advantage is that a studded structure can thus be formed on the backing side of the artificial turf mat, particularly when offset support loops, therefore formed outside the row of blades, are applied. This studded structure contributes to the shock absorption and energy restitution by the artificial turf when the artificial turf mat is laid on a flat stable ground such as asphalt, stone chippings or rigid geotextile.
[0009] The blades are advantageously formed from monofilament fibre. A filling material to be arranged on the artificial turf mat is hereby less confined than would be the case with the use of fibrillated fibres, whereby compaction of the filling material, and thereby hardening of the artificial turf field, can be prevented.
[0010] The invention also relates to an artificial turf field formed by an artificial turf mat as described above and a layer of loose filling material arranged thereon, the thickness of which is less than the length of the artificial grass blades.
[0011] The invention further relates to a method for forming an artificial turf mat, comprising of supplying a backing material, supplying an artificial turf material, forming a backing from the backing material, and connecting blades of the artificial turf material divided into rows to the backing. Such a method is also generally known.
[0012] The method according to the present invention is distinguished from the known methods in that the blades are connected to the backing such that their mutual spacing in a row is substantially equal to the mutual distance between adjacent rows and amounts to at least 10 mm.
[0013] When the backing material is formed into a fabric and the blades are connected to the fabric by tufting, it is recommended that the fabric is guided along a series of reciprocally moving tufting needles placed adjacently of each other at the row distance, and the speed of forward movement of the fabric and the stroke speed of the tufting needles are adjusted to each other such that between successive strokes of the tufting needles the fabric is displaced substantially through the row distance. The desired mutual distance between the blades can thus be ensured in simple manner. This is achieved even more simply when the fabric is stopped after each displacement through the row distance.
[0014] Finally, the invention further relates to a method for forming an artificial turf field by arranging on a ground an artificial turf mat as described above and spreading thereover a layer of loose filling material to a thickness which is less than the length of the artificial grass blades.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention is now elucidated on the basis of a number of embodiments, wherein reference is made to the annexed drawing, in which:
[0016] FIG. 1 shows a schematic perspective view of a part of an artificial turf mat according to a first embodiment of the invention,
[0017] FIG. 2 shows a cross-section along line II-II in FIG. 1 ,
[0018] FIG. 3 is a cross-sectional view corresponding with FIG. 2 of an artificial turf field based on an alternative embodiment of the artificial turf mat,
[0019] FIG. 4 is a top view of the artificial turf mat of FIG. 3 ,
[0020] FIG. 5 is a top view of an artificial turf mat with an alternative orientation of the rows of artificial grass blades,
[0021] FIG. 6 is a cross-sectional view corresponding with FIGS. 2 and 3 of an artificial turf field with yet another embodiment of the artificial turf mat,
[0022] FIG. 7 is a bottom view of an artificial turf mat with separately formed blades and support loops, and
[0023] FIG. 8 is a schematic view of a tufting machine with which an artificial turf mat according to the invention can be manufactured.
DETAILED DESCRIPTION
[0024] An artificial turf mat 1 ( FIG. 1 ) comprises a backing 2 , for instance in the form of a woven fabric or non-woven, to which is attached a large number of protruding artificial grass blades 3 . Blades 3 are distributed uniformly over rows 4 which are likewise uniformly distributed with an interspacing D. The mutual distance between blades 3 in a row 4 is designated with d. According to the present invention these distances are substantially corresponding and it is therefore the case that D˜d. A uniform distribution of the artificial grass blades over mat 1 is hereby obtained, which results in homogeneous properties in all directions of a playing field based on this artificial turf mat 1 .
[0025] In order to avoid studs of sports footwear catching in the blades 3 , and also to prevent a filling material 5 ( FIG. 3 ) spread on artificial turf mat 1 being held too firmly in place, whereby this material would be compacted and hardened, the mutual distances d, D are chosen to be relatively large. According to the invention these two distances amount to 10 mm or more, but more preferably to 13 mm or more, and most preferably to more than 16 mm.
[0026] In the shown embodiment the artificial grass blades 3 are tufted into backing 2 . Use is herein made for each row 4 of a continuous thread 6 , here of monofilament fibre, which is pressed into backing 2 in a regular pattern by an up and downward moving tufting needle 7 ( FIG. 8 ) and then held fast by looping hooks 10 , with the formation of loops 8 ( FIG. 2 ). During so-called cut pile tufting these loops 8 are severed or cut by means of knives 11 co-acting with looping hooks 10 , whereby two artificial grass blades 3 are formed in each case standing adjacently of each other.
[0027] Where mention is made in this text of the mutual distance d between adjacent blades, this does not therefore refer to the distance between blades 3 formed from a single loop 8 , but to the distance between two loops 8 and the pairs of blades 3 , 3 formed therefrom.
[0028] In order to strengthen the connection between the continuous tuft thread 6 and backing 2 , one or more further support loops 9 can be tufted between successive (pairs of) blades 3 . These support loops 9 protrude less far through backing 2 than the loops 8 from which the blades 3 are formed, nor are they cut open. Use can be made to form these support loops of separate or secondary looping hooks, and so as to prevent conflicts between these secondary looping hooks and the looping hooks for forming of blades 3 , the support loops 9 are preferably formed outside the row 4 ( FIG. 4 ).
[0029] Blades 6 are otherwise fixed in the usual manner in backing 2 after the tufting by providing the latter on the underside with an adhesive layer 13 which can be glued or welded to backing 2 .
[0030] For application of the invention it is not essential for the rows 4 to run straight. A different pattern, for instance with zigzag rows 4 ( FIG. 5 ), can also be envisaged as long as the mutual distance between the different artificial grass blades (or pairs of blades) 3 is substantially equal, and greater than 10 mm.
[0031] For forming of the artificial turf field 12 the artificial turf mat 1 is laid on a flat, slightly resilient ground 14 ( FIG. 3 ) and a layer of loose filling material 5 , for instance sand or a mixture of sand and rubber granules, is spread thereover. The thickness h of the layer of filling material 5 is chosen to be smaller than the height H of artificial grass blades 3 , so that these latter protrude above filling material 5 .
[0032] When blades 3 and support loops 9 are formed from a relatively thick fibre material or for instance a composite yarn bundle, the fibre or yarn segments 16 between blades 3 and support loops 9 protrude relatively far on the underside of backing 2 , whereby intermediate spaces or air chambers 17 are as it were formed therebetween ( FIG. 6 ). These intermediate spaces 17 contribute toward the shock absorption and energy restitution of artificial turf field 12 , which is particularly important when it is laid on a relatively flat and hard ground.
[0033] The artificial turf mat 1 as shown here can be manufactured on a tufting machine 15 which is of conventional construction and forms no part of the invention. Tufting machine 15 is provided with a frame with a bed 18 and a head 19 arranged thereabove. Present on the infeed side of bed 18 is a feed roller (not shown here) for the material of backing 2 , while on an opposite side there is arranged a wind-up roller (not shown) for the tufted artificial turf mat 1 , so that the material of the backing is transported over the bed in the direction of arrow A.
[0034] Situated in head 19 is an up and downward movable bar 20 in which is received a series of tufting needles 7 . The mutual distance between tufting needles 7 herein defines the row distance D. Guides 21 are further fixed to needle bar 20 for carrying to the needles 7 the fibre material 22 from which the blades 3 are formed.
[0035] A number of looping hooks 10 corresponding with the number of tufting needles 7 are arranged in bed 18 . These looping hooks 10 are fixed to arms 23 which are pivotable on a shaft 24 , so that looping hooks 10 are movable roughly parallel to the backing material and thus roughly transversely of needles 7 to take over the loops placed through the backing material by needles 7 . Adjacently of looping hooks 10 are further arranged the knives 11 co-acting therewith which cut open the loops to form said pairs of blades 3 .
[0036] The wind-up roller, needle bar 20 and pivot shaft 24 are driven by (servo) motors (not shown here) which are all connected to a control system. The insertion depth for instance of needles 7 can hereby be set, while by regulating the motors the insertion speed can be adapted to the winding-up speed such that between two successive insertion movements of needles 7 the material of backing 2 is moved forward each time through the distance d corresponding with the row distance D. In addition, it is possible to interrupt the winding-up each time the tufting needles 7 are inserted into backing 2 .
[0037] Use could optionally be made for the tufting of a tufting machine with two needle bars movable independently of each other and looping hooks and knives co-acting with the bars, such as described for instance in GB-A-2 357 301. The support loops 9 could hereby be tufted independently of blades 3 . For the support loops 9 , which could optionally be arranged crosswise over fibre 6 between successive (pairs of) blades 3 ( FIG. 7 ), use could then be made of another fibre material, for instance a much thinner yarn.
[0038] Although the invention is elucidated above with reference to an embodiment, it will be apparent that the invention is not limited thereto. The artificial grass blades 3 could thus be connected in a different way to backing 2 . Backing 2 could for instance be woven, wherein artificial grass blades 3 could be co-woven at the same time. Materials other than those discussed here are also conceivable. The artificial grass blades 3 , or at least the outer ends thereof, could thus be fibrillated. It is also conceivable for the loops 8 not to be cut open, whereby double blades 3 would in fact be formed.
[0039] The scope of the invention is therefore defined solely by the now following claims. | An artificial turf mat includes a backing and a number of protruding artificial grass blades divided into rows and connected thereto. The mutual distance between successive blades in a row is substantially equal to the distance between adjacent rows and amounts to at least 10 mm. Such an artificial turf mat can be used to form artificial turf fields, for example, on which sports, and in particular ball sports, are played. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a division of copending application Ser. No. 12/755,208 filed Apr. 6, 2010, which is a continuation-in-part of U.S. patent application Ser. No. 11/313,059 filed Dec. 19, 2005, the entire contents of each of which are incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] This invention is related to the evacuation from buildings that are three or more stories high in a fast and continuous method where a person fixed to a harness and hanging on a disc support is lowered to safety through a tube using a lesser pressure at the top of the tube and a higher pressure at the bottom of the tube. Also, its use is intended to also send firefighters and rescue persons upward to the upper floors to rescue persons that need help during a terrorist attack or a fire.
[0004] 2. Prior Art
[0005] After the 9-11 Twin Towers tragedy in New York and other catastrophes on buildings where human lives were lost, I decided to find a way to innovate the very obsolete ways of dealing with a fire in buildings where many persons would be defenseless and could not escape.
[0006] It was necessary to find a better way of evacuating people from buildings on fire with better equipment than is currently available in the market. At the time of the incident at the World Trade Center, it was also noticeable that the firefighters had an almost impossible task of getting to the upper levels because they had to use the same stairwell going up that the escapees were using going down to escape from the building.
[0007] In the early years of firemen and fire trucks, the best way to save persons in distress was by lowering them using a ladder that the fire engine truck had when it arrived to the site, where the fireman had to sometimes risk his own life to get these people down the ladder. Once the first person was on the ground, the brave fireman would sometimes be subject to deadly smoke inhalation while trying to get back and climb the ladder for a second time to find another person, who perhaps was with a child that would not go down the ladder due to panic. The fireman would have to wait until the child fainted or was calmed to get him down while at the same time other evacuees were waiting for the fireman to arrive to the assigned window of the building on fire to be rescued.
[0008] Many had to jump from high places and fall to a rescue device, such as a ring, that sometimes has over 8 men to hold it, abandoning more responsible tasks while in the rescue. The life saving process was slow. It ended in tragedies that added up costing many lives, and only a few would be alive to tell us about the story of the moments of terror that they had lived. The rescue equipment and available firefighter systems have changed very slowly over the years, and every day there is more need for a solution to this condition.
[0009] Nowadays the evacuation problem in case of an emergency is broader. With more buildings, and taller and taller buildings being constructed, more and more people are living or working in them than ever before. We have to add the unfortunate burden of having to deal with terrorist, arsonists, and lunatics who are repeatedly thinking of what, where, and when to strike to cause damage. There are occasions in a terrorist attack or fire that when the situation becomes so critical that the people entrapped by the fire or the smoke would finally decide to jump from the roof of the buildings to the ground because they would feel hopeless even knowing that with this action they would end their lives.
[0010] There are a number of U.S. patents and publications related to escape devices, but none has the advantages of the present invention.
[0011] Studies in areas related to pneumatic tube escape and rescue systems or people escape systems using air pressurized methods also have no similar disclosures as the present invention.
[0012] For example, the following patents were investigated thoroughly:
[0013] In the present invention, I present a vacuum pressure at the top of the tube or at the top of the disc support where in Pelley U.S. Pat. No. 4,372,423 a vacuum pressure on top of the parachute is not mentioned. The top of the tube in the Pelley system is open and there are no connotations on Pelley's claims that the balloon shaped parachute requires a vacuum pressure on its top, nor is it understood by looking at the Pelley patent. I understand that my invention does not conflict with the idea present in the Pelley patent.
[0014] In Marcu (U.S. Pat. No. 5,597,358) no vacuum pressure is mentioned or implied. Since Marcu needs an open top or an opening above the capsule to release the air contained at the upper side of the capsule while going upward with the central capsule valve closed, even though in Claim 1 and in the 9 th paragraph of the 24 paragraphs Marcu mention that he has an adjustable Droseling valve (a flow valve) at the upper part of the tube, this would still not imply having a vacuum pressure in the system. Marcu also has to have the top open to free air when his capsule drops at a free fall speed. In no instance may there be a vacuum pressure in the upper area of the tube in Marcu. This would be a slowing mechanism when Marcu is trying to accelerate. This reasoning is made because in all instances during the climbing of the capsule and the free fall of the capsule, Marcu has to have atmospheric pressure above the capsule in order to have his capsule go up to the highest point before and after the capsule drops on a free fall, which implies that Marcu may not have any type of negative or vacuum pressures in the system, otherwise it would not perform properly. As for the stopping of the capsule at the end of the run, Marcu uses the central valve in the capsule with the desmodromic mechanism (lever actuated valve) in the closed position to decelerate and stop the capsule with positive pressure (Marcu also has a set of springs at the bottom to have an additional mechanical way of stopping the capsule in case there is a mishap if the valve does not close properly). Therefore at all times the capsule is controlled with a positive pressure. Marcu also mentions the Droselling valve that is placed from the inside to the outside at the bottom of the tube where this valve is used to release the positive pressure when bringing the capsule to a stop. This mechanism is not similar to the present invention, especially because the invention that Marcu discloses is not related to escape devices.
[0015] On the contrary, the vacuum and/or negative pressures are pertinent to the present invention and are not known to have been mentioned before in prior inventions. The stopping of the present invention with a vacuum pressure for an escape device is a novelty and these are not implied in the Marcu system.
[0016] Another fact about the Marcu system is that the valves, being a Desmodromic valve or a Droselling valve, are variable valves and in the present invention the holes and/or preset valves are intended to stay open (not variable) due to the care that must be exerted due to the fact that the present invention deals with the fall of live persons. The present invention shows that there is an optimum pattern in the preset valve arrangement, the amount of preset valves or holes, the sequence and location of these preset valves on the length of the tube.
[0017] Fuhrmann (U.S. Pat. No. 7,188,705) is a patent related to an escape system consisting of a cup that falls through a tube controlled by a positive pressure exerted below the cup formed escape device. It defers from the present invention in various ways. First, Fuhrmann forms a cup where a person is sitting in the cups base, whereas the present invention has a disc support that is placed at the top of the escapee. Second, the decelerating mechanism on the Fuhrmann system is created by reducing the width of the tube at several consecutive intervals thus reducing the diameter of the tube and controlling the escape of the air flow. In the present invention, however, the air is dissipated by an arrangement of holes or preset valves that are placed from the inside to the outside of the tube. Third, the fall control of the Fuhrmann invention is obtained by two iris valves placed in the pathway of the tube one after the other, where in the present invention acceleration/deceleration is exerted by a vacuum pressure above the disc support, or a pressure difference between the upper and lower side of the disc support, without a valve in the cross section of the tube. Fourth, the Fuhrmann invention slows down due to a positive pressure below the cup whereas in the present invention for the escapees the acceleration and the deceleration are controlled through a vacuum pressure.
[0018] Xia (U.S. Publication No. 2003/0116380) uses forced air induced in the descent of escapees. The jets of Xia have an exterior pressure of high inward free air pressure of over 1.5 psi to 6 psi in pressure. Xia uses a powerful jet to stop the persons from falling at the end of the tube, which could be dangerous. To obtain control of a falling object that measures basically 200 square inches on a very tight tube, as in Xia, would need at least 6 psi (pound per square inch) of air. The turbine would have to be very big as this type of free air flow at 6 psi would have a large loss. Falling through a duct with a direct flow of air while avoiding from being hit against the ground floor is believed to be impractical.
SUMMARY
[0019] The present invention is to be used during a terrorist threat or a fire as a fast fire escape and a rescue device to remove people from a multistory building. This mechanism is easy to use and has fast evacuation results. In fact, it may be used immediately after the notion of the fire is known. There is no intervention of outside personnel or Firemen personnel. The invention includes a disc support attached to a strapped harness which is fixed to a person, where this disc support slides through a tube generating a lower pressure at the top thereof and a higher pressure at the bottom thereof, thus controls the person's descent to safety.
[0020] It not only helps the escapee to descend to safety, but it also is a way to send firefighters through the rescue device upward to the upper floors in a fast and safe way. Firefighters would be attached with a harness to the disc support to get through the tube up to the upper floors to help people that are trapped, unconscious or impaired and to help them get down through this system or through another escape device. The firefighters would not need to use the stairways which are used by the stampede of people evacuating the building, which is known to interfere with the firemen trying to get to the upper floors. It is important to realize that being the first minutes of a fire the only time one has to evacuate a building, it is of importance that one may start the evacuation without having to wait for anyone.
[0021] An object of the invention is to improve the escape of persons from upper floors of a building in danger, e.g. on fire, by controlled descent through a generally vertical tube, supported by a disc which contacts and slides within the interior of the tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1A shows a high rise building having a plurality of escape devices according to the present invention.
[0023] FIG. 1B shows an cross section of the high rise building with an escape device application.
[0024] FIG. 1C shows a cross section of the high rise building with a rescue device application.
[0025] FIG. 2A shows a vacuum and/or negative pressure version of the escape device.
[0026] FIG. 2B shows a positive pressure version of the escape device.
[0027] FIG. 3A shows a person fixed to an attachment hanging below a disc support that slides through a tube, according to an embodiment of the escape device shown in FIG. 2A and FIG. 2B .
[0028] FIG. 3B is a perspective view of an embodiment of the disc support.
[0029] FIG. 3C shows a side view of the attachment.
[0030] FIG. 3D shows a top view of the attachment.
[0031] FIG. 4A shows a bottom view of the disc support in FIG. 3B .
[0032] FIG. 4B shows the top view of the disc support in FIG. 3B .
[0033] FIG. 4C shows a cross section of the disc support in FIG. 3B .
[0034] FIG. 4D shows a top view of a hole and a knob in the disc support in FIG. 4B .
[0035] FIG. 4E shows a bottom view of the hole and the valve, where the valve is in an open position.
[0036] FIG. 4F shows the bottom view of the hole and the valve, where the valve is in a half closed position.
[0037] FIG. 4G shows the bottom view of the hole and the valve, where the valve is in a closed position.
[0038] FIG. 5A shows an embodiment of a vacuum and/or negative pressure version of the escape device and a procedure of using the vacuum and/or negative pressure version of escape device.
[0039] FIG. 5B and FIG. 5C show a structure of roller bearings and a procedure of using the roller bearings after sliding out of the tube.
[0040] FIG. 6A shows an embodiment of a positive pressure version of the escape device and a procedure of using the positive pressure version of escape device.
[0041] FIG. 7A shows an embodiment of a rescue device.
[0042] FIGS. 8A-8E shows another embodiment of the escape device where the tube is a foldable double wall duct.
[0043] FIGS. 9A-10E show another embodiment of the rescue device where the tube is a foldable double wall duct.
[0044] FIGS. 11A-11F shows another embodiment of the disc support.
[0045] FIG. 12A shows a top view a large disc support with the pod slots.
[0046] FIG. 12B shows a cross section of the large disc support.
[0047] FIG. 12C shows a cross section of the large disc support showing a pod slot and the attachment with the belt and the buckle at the left side and at the center the hole and the valve attached to the knob.
[0048] FIG. 12D shows a cross section of the disc large support showing the pod clip engaged inside the disc support.
[0049] FIG. 12E shows a longitudinal section of the disc large support showing the pod clip engages inside the disc support with a clip lock in locked position.
[0050] FIG. 13A shows an embodiment of negative pressure version of the escape device, where a plurality of persons can escape using the device simultaneously.
[0051] FIG. 14A shows an embodiment of positive pressure version of the escape device, where a plurality of persons can escape using the device simultaneously.
[0052] FIG. 15A shows a person enters into the tube through a door at the upper floor and stands on a plank, where the person is wearing the attachment attached to the disc support in the closed position, according to an embodiment.
[0053] FIG. 15B shows the person with the disc support in a closed position being placed inside the dome.
[0054] FIG. 15C shows the person with the disc support obtaining a vacuum and/or negative pressure inside a dome and the door is in a locked position.
[0055] FIG. 15D shows the plank being released and the person start to descend.
[0056] FIG. 15E shows the floor plank is totally moved out of the way from the path of the disc support and the floor plank is placed inside the exterior sealed compartment and where the person attached to the disc starts descending through the tube.
[0057] FIG. 15F shows the person attached to the attachment and the disc support continue descending through the tube.
[0058] FIG. 16A shows a top view a disc support, according to an embodiment.
[0059] FIG. 16B shows a side view of the disc support in a closed position.
[0060] FIG. 16C shows a side view of the disc support in a half closed position.
[0061] FIG. 16D shows a side view of the disc support in an open position.
[0062] FIG. 16E shows the bottom view of the disc support.
[0063] FIG. 16F shows a disc support in a multi ring setup arrangement, according to an embodiment.
[0064] FIG. 16G shows the disc support in a multi ring setup arrangement having a traverse deflection when passing through a deflected tube.
[0065] FIG. 17A shows a large disc support for a plurality of persons with the nonporous flexible material and the beam, according to another embodiment.
[0066] FIG. 17B shows a side view of the large disc support in a closed position.
[0067] FIG. 17C shows a side view of the large disc support in a half closed position.
[0068] FIG. 17D shows a side view of the large disc support in an open position.
[0069] FIG. 18A shows a top view of a person on top of a floor plank in a closed position inside a tube, according to an embodiment.
[0070] FIG. 18B shows a left side view of the person on top of the floor plank in the closed position inside the tube.
[0071] FIG. 18C shows a frontal side view of the person 17 on top of the floor plank in a closed position inside a tube.
[0072] FIG. 18D shows a top view of the floor plank in a half closed position inside the tube.
[0073] FIG. 18E shows a left side view of the floor plank in the half closed position inside the tube.
[0074] FIG. 18F shows a frontal view of the floor plank in the half closed position inside the tube.
[0075] FIG. 18G shows a top view of the floor plank in an open position inside the tube.
[0076] FIG. 18H shows a left side view of the floor plank 88 in the open position inside the tube.
[0077] FIG. 18I shows a front view of the floor plank in the open position inside the tube.
DETAILED DESCRIPTION OF THE INVENTION
[0078] Embodiments of the present invention will now be described more fully with reference to the accompanying drawings, in which the embodiments are shown. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, the embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to one skilled in the art. In the drawings, the dimensions and regions are exaggerated for clarity. Like reference numerals in the drawings denote like elements, and thus, their description will not be repeated.
[0079] Accordingly, while embodiments of the invention are capable of various modifications and alternative forms, only the embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit embodiments of the invention to the particular forms disclosed, but on the contrary, embodiments of the invention are to cover all modifications, equivalents, and alternatives falling within the scope of the invention. Thus, parts in one drawing may be substituted for parts in other drawings below to thus provide additional variations or embodiments.
[0080] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of embodiments of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0081] It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “on” versus “directly on”, “between” versus “directly between”, “adjacent” versus “directly adjacent”, etc.).
[0082] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of embodiments of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising,”, “includes” and/or “including”, when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0083] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the Figs. For example, two Figs. shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0084] Although the embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.
[0085] FIG. 1A and FIG. 1B show that when in an emergency due to terrorist threat or a fire on a building, there is a method of fast escape from a building into safety. As is shown on FIG. 1A and FIG. 1B , the building may be three (3) floors to more than 120 stories, and a person may go through an entrance 72 into a cabin 78 at a roof floor 74 or at an upper floor 75 , where a vertical tube 80 is connected to a lower floor 76 or to ground floor 77 where an exit 32 is located.
[0086] FIG. 1C shows that when in emergency due to terrorist treats or a fire on a building, there is a method of rescue by firefighters using a positive and a negative air pressure from a blower as to rise themselves through a tube 80 to rescue injured persons 17 located at an upper floor 75 . To this end, a firefighter may go through an entrance 72 into a lower chamber 78 on the ground floor 77 or at a lower floor 76 , which is connected to the upper floor through the vertical tube 80 and rise to an upper floor 75 or to the roof floor 74 , where an exit 32 is located, reaching the place where the firefighter may find entrapped persons waiting to be rescued.
[0087] FIG. 2A shows one example embodiment of the escape device. The tube 80 includes a first entrance 72 at the roof floor 74 and an open end at the bottom floor. The tube 80 also includes, from the upper side to the lower side thereof, respectively, a first section 82 , a second section 83 , and a third section 84 . Along the first section 82 , there are provided on the wall of the tube 80 a plurality of first holes and/or preset valves 47 distributed along the longitudinal direction of the tube 80 . Along the second section 83 , there are provided on the wall of the tube 80 a plurality of second holes and/or preset valves 70 distributed along the longitudinal of the tube. There are no holes and/or preset valves along the third section 84 .
[0088] Each hole and/or preset valve includes a first side connected to the inner space of the tube 80 and a second side parallel connected to the rest of the holes and/or preset valves by an otherwise closed channel 803 , so that each hole and/or preset valve is connected to every other holes and/or preset valves. Therefore, air in the tube can circulate from a lower portion of the tube to an upper portion of the tube, or vise versa, through the holes and/or preset valves 47 , 70 and the channel 803 .
[0089] Further, the escape device also includes a disc support 79 having an upper side 791 , a lower side 792 , and a diameter that matches the inner diameter of the tube 80 , so that it is capable of sliding within the tube and which divides the inner space of the tube 80 into two parts: the upper space 801 above the disc support 79 and the lower space 802 below the disc support 79 .
[0090] To safely escape the building 71 , a person 17 who has attached a harness 37 connected to the disk support 79 first enters the tube 80 through the door 22 after passage through the entrance 72 at the roof floor 74 or the upper floor 75 , and then hangs himself or herself below the disc support 79 by the harness or attachment 37 . The attachment 37 is desirably a four-point harness system including a buckle 38 and a belt 39 , where a person 17 can be fixed thereto and rides or slides downwardly against the smooth surface 81 of the tube 80 , as shown in FIGS. 3A-3D . Because of the weight of the person and the effects of gravity, he/she will slide downwardly through the vertical tube 80 from the top thereof towards the bottom thereof.
[0091] The downward motion of the disc support 79 compresses the air in the lower space 802 and increases the volume of the upper space 801 , and thus generates an air pressure difference between the upper space 801 and lower space 802 . In the event that only the upper space 801 is encapsulated, as shown in FIG. 2A , the motion will decrease the air pressure of the upper space 801 only. The air pressure in the lower space 802 remains at atmosphere pressure. In the event that only the lower space 802 is encapsulated, the motion will increase the air pressure of the lower space 802 , but the upper space 801 will remain at atmosphere pressure as shown in FIG. 2B . When both of the upper space 801 and the lower space 802 , are encapsulated, the motion will decrease the air pressure of the upper space 801 and increase the air pressure of the lower space 802 . In any case, the pressure difference between the lower space 802 and upper space 801 (e.g., 0.4 psi-1.2 psi) generates an upward force on the disc support 79 that counteracts against the weight of the person. That said, the upward force is equivalent to a damping force to the downward motion of the disc support 79 .
[0092] The amplitude of the upward force positively relates to the amplitude of the pressure difference between the lower space 802 and the upper space 801 . In an ideal situation when friction between the disc support 79 and the tube 80 is trivial, if the pressure difference is too small to overcome the weight of the person, the descending motion accelerates, otherwise, when the pressure difference is increased sufficiently so that the upward force is significant compared to that of the weight of the person, his/her descending motion will decelerate.
[0093] Driven by the pressure difference, when the disc support 79 is moving in the first section 82 or in the second section 83 , the air in the lower space 802 flows to the upper space 801 through the holes and/or preset valves 47 , 70 . Due to the descending motion of the disc support 79 , the volume of the upper space 801 increases constantly and the volume of the lower space 802 decreases constantly. The air exchange between the lower and upper spaces 802 , 801 partially compensates the volume change and therefore at least partially offsets the change of the pressure difference between the lower space 802 and the upper space 801 .
[0094] The extent of such compensation/offset depends on the flux of the air between the upper space 801 and the lower space 802 . By distributing the holes and/or preset valves 47 , 70 in a predetermined pattern, the flux rate of the valves 47 , 70 , and the overall flux of the air between the upper space 801 and the lower space 802 can be controlled, so that when the person is traveling through the first section 82 of the tube 80 , the descending motion of the disc support 79 creates a predetermined lesser pressure difference, thus a predetermined acceleration to the motion; when the person is traveling through the second section 83 of the tube 80 , the motion of the disc support 79 creates a predetermined larger pressure difference, thus a predetermined deceleration to the motion.
[0095] As an example, FIG. 2A shows that the holes and/or preset valves 47 in the first section 82 are larger, whereas the holes and/or preset valves 70 in the second section 83 are smaller. Other configurations and distributions for the holes and/or preset valves may also be applied to these sections to achieve the above-mentioned predetermined acceleration arrangement.
[0096] When the disc support 79 arrives to the third section 84 of the tube 80 , where there are no holes and/or preset valves, no air exchange occurs between the lower space 802 and the upper space 801 , and therefore there is no air pressure difference being offset by the air exchange. As a result, the air pressure difference between the upper and lower spaces 801 , 802 keeps increasing along with the descending motion of the disc support 79 , thus the disc support 79 keeps decelerating, until it reaches the open end of the tube 80 where the lower floor 76 or the ground floor 77 is located, at which place the velocity of the disc support 79 decreases to zero. After landing, the person 17 can then remove the disc support 79 from the tube 80 and release himself/herself from the attachment 37 and proceeds toward the exit 32 .
[0097] Various configurations can be applied to the disc support 79 . For example, it may simply be a high profile disc with rings 793 to connect to the attachment 37 , as shown in FIG. 3B . It may further include a valve system 48 for speed control, as shown in FIGS. 4A-4G which illustrate an embodiment of the disc support 79 , wherein the disc support 79 has a hole 48 and a valve 49 on the lower side 792 to adjust the descending speed of the person 17 corresponding to her weight. Further, on the upper side 791 of the disc support 79 , there is also provided with a knob 51 connected to the valve 49 for turning the valve 49 which has three positions, namely closed, semi-closed, and open as shown in FIGS. 4E to 4G . The valve 49 is set at a position according to the weight of the person. The adjustment of the valve adjusts the air flux through the hole 48 when the disc support 79 is moving through the tube 80 , and thus adjusts the pressure difference between the upper space 801 and the lower space 802 , and accordingly adjusts the acceleration or deceleration of the disc support 79 . FIGS. 4A-4G show that the hole 48 locates at the edge of the disc support 79 . It can certainly be arranged to other place of the disc support, such as to the center thereof
[0098] FIGS. 16A-16D show another embodiment of the disc support 79 . According to the embodiment, the disc support 79 is a two layer structure. It includes a disc 794 and a lower ring 87 connected by two levers 62 and a nonporous flexible skirt 152 . The lower ring 87 has an outer diameter substantially being the same as that of the disc 794 . The outer skirt 152 connects the outer peripheral of the lower ring 87 with the outer peripheral of the disc 794 , so that when the lower ring moves towards or away from the disc 794 , i.e., when the disc support 79 is in a closed/open position, the skirt 152 is folded/deployed. Further, the lever 62 is a mechanism with two bars 621 , 622 . Each bar 621 / 622 connects to the other bar by a hinge 623 at one side, and connects to either the disc 794 or the lower ring 87 by a hinge 624 at the other side. The lever 62 serves as a skeleton to the folding and deploying of the skirt 152 , preventing the skirt 152 from being torn away from the disc 794 or the lower ring 87 when the disc support 79 is opened by a force.
[0099] The lever 62 also helps the planar surfaces of the disc 794 and the lower ring 87 face each other when the disc support 79 is closed/opened. When the disc support 79 slides through the tube 80 , the planar surfaces of the disc 79 and lower ring 87 remains perpendicular to the longitudinal axis of the vertical tube 80 , thus avoiding a turn over of the disc support 79 . Such configuration also helps maintain a minimum and/or a predetermined the air pressure loss that occurs between the disc support edges and the interior surface of the tube 80 , thus allowing a controlled descending of the disc support and the person supported thereby.
[0100] The disc support 79 can also have multiple layers of skirts and rings. FIG. 16F shows an embodiment of the multi ring setup arrangement and the person supported thereby.
[0101] According to the embodiment shown in FIG. 16F , the disc support includes the disc 794 , several intermediate rings 86 , and a lower ring 87 . The disc 794 and the rings 86 , 87 below the disc 794 are connected in series, forming a multiple layer structure. Each layer is connected to another by a lever 62 and a skirt 152 in a similar manner as that of the two layer disc support described above. Such multi-layer structure provides an improved air sealing when the disc support travels through the tube 80 . This is because due to mismatch between the tube 80 and the disc support 79 , there is always a space, no matter how small it is, between the inner surface 81 of the tube and the outer peripherial of the disc support 79 . When there is only one layer, the air only needs to pass through one layer of the space to leak from below the disc support 79 to above the disc support 79 . With a multi-layer structure, however, the air has to pass several layers of spaces to leak from below the disc support 79 to above the disc support 79 . Each layer of the space increases the difficulty for the leakage, thereby creating a better sealing between the space below the disc support 79 and the space above the disc support 79 , thereby providing the disc support 79 better controllability for the descending movement.
[0102] The multiple layer structure also provides the disc support 79 with a certain degree of flexibility when moving through the tube 80 . As shown in FIG. 16G , when said tube 80 is deflected in a traverse direction, or has minor variation in diameter, symmetry, position, or is off centered or with an imperfect roundness cross section, the multi-layer disc support 79 is capable of deforming in a traverse direction to maintain a good sealing effect between the air above and below it, thus permitting a desired control over the descending motion.
[0103] FIGS. 11A-11F show another embodiment of the disc support. According to this embodiment, the disc support is in the form of a ring shaped support 79 slidable against the smooth surface 81 of the tube 80 . The ring shaped support 79 connects to an attachment 37 and a pant 55 , so that a person 17 can go into and be supported by the pant 55 and sit and fix herself on the attachment 37 . The pant also includes a belt 39 and a buckle 38 to further fix the person 17 at her waist, and an elastic band at each trousers leg to fix the person 17 at her thighs minimizing air leakage between the pant 55 and the person 17 . When she is sitting in the pant 55 and sliding through the tube 80 , a lower pressure 41 at the top of the ring shape support 79 and/or a higher pressure 42 below the ring shaped support 79 are generated, whereby her descending speed can be controlled.
[0104] In addition, the ring shaped support 79 can also include a hole 48 , a valve 49 on the lower side of the ring shaped support 79 , and a knob 51 connected to the valve 49 on the upper side of the ring shaped support 79 . By turning the knob 51 , the person 17 can adjust position of the valve 49 over the hole 48 , thereby adjust the flux rate of the air in the tube 80 that flows through the hole 48 , and thus control the descending acceleration/deceleration according to the person's weight.
[0105] FIG. 2B shows another embodiment of the escape device, in which the lower end of the tube 80 is closed and the upper end of the tube 80 is opened. The tube 80 further includes a second door 22 at the lower end thereof. When a person 17 attached to a disk support 79 with an attachment 37 goes through an entrance 72 at the roof floor 74 or the upper floor 75 , she may then descend through the vertical tube 80 . The descending motion does not change the pressure in the upper space 801 , and creates a larger pressure or positive pressure in the lower space 802 , and thus generates a pressure difference between the upper space 801 and the lower space 802 . The pressure difference is controlled in a manner so that the disc support 79 first accelerates while traveling through the first section 82 , where the holes and/or preset valves 47 are located. When the disc support 79 passes the second section 83 , where the holes and/or preset valves 70 are located, the pressure difference is so controlled to provide a predetermined deceleration for the disc support 79 , and thus lower the descending speed of the disc support 79 until the disc support 79 arrives to the third section 84 of the tube 80 . Since there are no holes and/or preset valves in the third section 84 , no air communicates between the upper and lower space 801 , 802 . Therefore no offset to the pressure difference is obtained therebetween. As a result, the length of the third section is configured in a way that the disc support 79 will stop when it reaches the lower floor 76 or the ground floor 77 , where the person will open the door 22 to go toward the exit 32 .
[0106] FIG. 5A shows a procedure of escape using a vacuum version of the escape device. In this procedure, a person 17 fixed by an attachment 37 to a disk support 79 first enters into the entrance area 72 at the roof floor 74 or the upper floor 75 and then closes the door 22 . Then the person 17 descends through the vertical tube 80 . The descending motion creates a lower pressure 41 or vacuum above the disc support 79 . The disc support 79 initially accelerates at a predetermined rate while traveling through the first section 82 (approximately 85% of the total length) where the holes and/or preset valves 47 are located. Then the disc support 79 passes the second section 83 (approximately 11% of the total length) of holes and/or preset valves 70 where a predetermined deceleration immediately starts reducing the speed of the disc support 79 . At the third section 84 (approximately 4% of the total length) where there are no holes and/or preset valves, no pressure offset is obtained by the exchange of air between the upper space and the lower space. As a result, the disc support 79 will come to a stop when the person reaches the lower floor 76 or the ground floor 77 where the person will go to exit 32 .
[0107] As shown in FIG. 5B and FIG. 5C , after leaving the tube 80 , two inclined lateral trays 24 and roller bearings 25 are provided at the lower end of the tube 80 to receive the disc support 79 . The weight of the disc support 79 , together with the weight of the attachment 37 and the person 17 drives the disc support 79 laterally to the lower floor 76 or to the ground floor 77 and then to the exit 32 , so that a plurality of persons can be rescued one after another in a streamlined fashion so as to increase the amount of persons being evacuated through the escape tube at a given time.
[0108] The entrance of the escape device at the higher floor may have various configurations. For example, FIGS. 15A-15F illustrate another embodiment of the entrance, the door, and the end portion for the tube 80 of the escape device as well as a procedure of preparing the descending.
[0109] As shown in FIG. 15A , the door 22 is configured to be on the wall of the tube 80 . Inside the upper portion of the tube 80 , there is provided an exterior compartment 90 on the wall thereof, so that an extra space is available in the wall of the tube 80 . Further, the tube 80 also includes a plank 88 being hinged in the compartment 90 at the same height of the upper floor 75 , so that when the plank 88 is in a horizontal position, it supports a person enters into the tube 80 from the door 22 ; and when the plank 88 is rotated down to a vertical position, it is completely encompassed by the space of the compartment 90 . The connection between the compartment 90 and the tube 80 is perfectly sealed. Therefore, there are no air leaks in and out of the tube 80 from the compartment 90 .
[0110] To prepare for descending, the person 17 fixed on the attachment 37 and the disc support 79 first enters into the entrance 72 at the upper floor 75 , then opens the door 22 and enters into the tube 80 and steps onto the plank 88 , as shown in FIG. 15A . At this time, the disc support 79 is in the closed position 60 . The person then raises the disc support 79 and fits it to the inner smooth surface of a dome 91 in the upper end of the tube 80 , as shown in FIG. 15B . Next, the person closes the door 22 , and pulls down the disc support 79 for a small distance to generate a predetermined negative pressure and/or vacuum pressure 13 in the dome 91 above the disc support 79 . As shown in FIG. 15C , because of the interaction between the downward pulling force and the upward sucking effect of the negative pressure and/or vacuum pressure 13 , the disc support 79 is now in the half closed position 58 , i.e., the skirt 152 is partially deployed. The negative pressure and/or vacuum pressure is large enough to sustain the disc support 79 stay in position statically until a force sufficiently large to pull the disc support 79 downward, permitting an initial slow movement of the disc support 79 along the length of the tube 80 .
[0111] Also, the negative and/or vacuum pressure 13 is directed by mechanical means to the door 22 and to the floor plank 88 in a way that the floor plank 88 will not release unless there is a vacuum 13 on the dome 91 and the door 22 is in a locked position.
[0112] Next, as shown in FIGS. 15D-15F , when the door 22 is locked in the closed position, the plank 88 is pivoted into the exterior sealed compartment 90 , thereby completely opens the tube 80 below the person 17 , releasing her to the descending motion. FIGS. 18A-18I illustrate top views and side views of the plank 88 and compartment 90 , as well as how the plank 88 releases the person 17 for the descending motion.
[0113] Now referring to FIG. 6A . FIG. 6A shows a procedure of escape using a positive pressure version of the escape device. A person 17 first goes through the entrance 72 at the roof floor 74 or the upper floor 75 , and then fixes herself to an attachment 37 and a disc support 79 guided by the rail 332 . The person 17 then places herself in position for the descend through the vertical guides 34 through the tube 80 . In a positive version of the escape device, the descending motion of the disc support 79 creates a higher pressure 42 or positive pressure 14 below the disc support 79 than the pressure above the disc support 79 . As stated above, the disc support 79 accelerates to an optimum/predetermined speed while traveling through the first section 82 (approximately 85% of the total length), where the holes and/or preset valves 47 are located, until the disc support 79 enters into the second section 83 (approximately 11% of the total length), where the holes and/or preset valves 70 are located. When the disc support 79 enters into the second section 83 , a deceleration immediately starts, bringing the disc support 79 to a lower speed until it enters into the third section 84 (approximately 4% of the total length), where no holes and/or valves are provided. Since there is no air pressure offset/released, the disc support 79 will come to a stop when the person reaches the lower floor 76 or the ground floor 77 , where she will open the door 22 to go toward the exit 32 .
[0114] To further increase the efficiency of evacuation, the escape device may be configured to send a plurality of persons through the tube 80 simultaneously. For example, according to another embodiment shown in FIGS. 12A-14A , the escape device includes a disc support 79 large enough for a plurality of persons and a correspondingly larger tube 80 that matches the disc support 79 . On the lower side of the disc support 79 , there is provided a plurality of pod slots 67 , each of which is capable to hang an attachment 37 for a person. The configuration of the pod slots 67 and the corresponding portion of the attachment 37 to hook up with the pod slots 67 may be of any suitable forms. For example, each attachment 37 includes a T-shaped one-point pot clip 68 . Each pod slot 67 is formed by a T-shaped groove with a cylindrical slot at one side thereof, so that an individual attachment 37 can be hooked by the T-shaped groove through the one-point pot clip 68 . Once the pod clip 68 is placed into the pod slot 67 and it enters into its working position, the pod lock 69 falls back and does not release the pod clip 68 until the person arrives to the lower floor. There can also be provided a hole 48 , a valve 49 , and a knob 51 in the disc support 79 for additional descending control, as set forth in the previous embodiments.
[0115] As an another example, FIGS. 17A-17D shows another embodiment of the large disc support for a plurality of persons. The large disc support includes a disc 798 , a lower ring 870 below the disc 798 , a nonporous flexible skirt 154 , and several parallel cross beams 85 . The lower ring 870 has an outer diameter substantially equals to the diameter of the disc 798 . the skirt 154 connects the outer pheripheral of the lower ring 870 with the outer peripheral of the disc 798 , so that when the lower ring moves towards/away from the disc 798 , i.e., when the disc support 79 is in a closed/open position, the skirt 154 is folded/deployed. Further, each of the cross beams 85 is connected to the bottom of the disc 798 by a hinge 850 , and a lever 626 interacts with the beams 85 so that when the cross beams 85 rotate towards the disc 798 , the large disc support 79 is closed and when the cross beams 85 rotate away from the disc 798 , the large disc support 79 is opened.
[0116] To have the pod clips 68 ready for use, the beams 85 rotate around the hinge 850 to be perpendicular to the surface of the disc 798 . Accordingly, the large disc support 79 is opened and the height of which is expanded from 4 inches to a full 16 inch. Further, the pod clips 68 and the cross beams 85 are arranged to take into account the width and the size of the persons it takes and are set as to have the persons travel in a comfortable way, without having these persons touching each other at the front and back of their bodies.
[0117] Once the persons leave the disc and escape from the building, the large disc support 79 is rotated 90 degrees into the closed position and the beams too will be placed the closed position, so that the large disc support becomes 75% thinner, and thus easier for storage.
[0118] FIG. 13A shows an embodiment of negative pressure version of the rescue device using the large disc support 79 . In a rescuing process, a plurality of the persons 17 , connected to individual attachments 37 , walk to the entrance 72 through a door 22 that will keep the lower pressure 41 or negative pressure 13 at the top of the tube 80 . When all of the persons 17 are readily fixed to the disc support 79 , they then place themselves in position for descending through the vertical guides 34 and descend themselves through the vertical tube 80 . Because the door 22 of the upper entrance 72 is closed, the descending motion creates a lower pressure 41 or negative pressure 13 above the disc support 79 . Because the lower end of the tube 80 is open, the air pressure under the disc support 79 remains atmosphere pressure. The pressure difference between the lower pressure 41 above the disc support 79 and the atmosphere pressure 26 below the disc support 79 is adjusted so that the disc support 79 initially accelerates to an optimum/predetermined speed while the disc support 79 is traveling through the first section 82 (approximately 85% of the total length), where the holes and/or preset valves 47 are located. When the disc support 79 passes the second section 83 (approximately 11% of the total length), where the holes and/or preset valves 70 are located, a deceleration immediately starts, bringing the disc support 79 to a lower speed until it reaches to the third section 84 (approximately 4% of the total length) where there are no holes and/or preset valves. Since there is no air pressure offset/released, the disc support 79 will further decelerate and eventually come to a stop when the person reaches the lower floor 76 or the ground floor 77 . The person 17 then moves toward the exit 32 .
[0119] FIG. 14A shows an embodiment of positive pressure version of the escape device using the large disc support 79 . When all of the persons 17 are readily fixed to the disc support 79 , they then place themselves in position for descending through the vertical guides 34 and descend themselves through the vertical tube 80 . Because the lower end of the tube 80 is connected to the lower chamber, and the door 22 of the lower chamber is closed, the descending motion of the disc support 79 creates a higher pressure 42 or positive pressure 14 in the tube 80 below the disc support 79 . Because the entrance 72 is open to the atmosphere, the pressure above the disc support 79 remains atmosphere pressure. As set forth above, the pressure difference above and below the disc support 79 is controlled so that the disc support 79 initially experiences an acceleration until it reaches an optimum/predetermined speed while traveling through the first section (approximately 85% of the total length), where the holes and/or preset valves 47 are located. When the disc support 79 enters into the second section (approximately 11% of the total length), where the holes and/or preset valves 70 are located, a deceleration immediately starts, bringing the disc support 79 to a lower speed until it enters into the third section (approximately 4% of the total length), where there are no holes and/or preset valves. Since there is no air pressure offset/released, the disc support 79 will be further decelerated and eventually stops when the person reaches the lower floor 76 or the ground floor 77 , where the person will open the door 22 to go toward the exit 32 .
[0120] In addition to safely rescue persons from a higher floor to a lower floor in a building, the present invention can also be applied to send a person, such as a fireman, from a lower floor to a higher floor in a building.
[0121] FIG. 7A shows an embodiment of a rescue device used to lift upward a firefighter 18 or a plurality of firefighters 18 . The rescue device comprises one lower chamber 78 , an upper chamber 781 , a tube 80 therebetween, a disc support 79 slidable in the tube 80 , and a blower 43 . The blower 43 connects to the lower chamber 78 by a first channel 784 and connects to the upper chamber by a second channel 786 . Operating the blower 43 generates a higher pressure 42 in the lower chamber 782 and/or a lower pressure 41 in the upper chamber 781 . By using the pressure difference between the lower pressure 41 and the higher pressure 42 , the fireman 18 slides upward through the tube 80 to an upper floor.
[0122] As shown on FIG. 7A , the firefighter 18 with the disc support 79 enters into the tube 80 and ascends towards the upper floor 75 . At the end of the ascend when the disc support 79 reaches the section there is a plurality of holes or preset valves 702 , where these holes or preset valves create a bypass between the upper and the lower sides of the disc support 79 , reducing the speed of the ascend as the disc support 79 advances. Consequently, the disc support 79 stops at the height of the inclined lateral tray roller system 65 , where the disc support 79 is unhooked and carried by the firefighter 18 who leaves through door 22 to continue through exit 32 .
[0123] To obtain an additional control over the ascending speed, the disc support 79 may further include a hole 48 and/or a valve 49 , shown in FIGS. 4A , capable of adjusting the amount of air flow to adjust the upward speed of the disc support 79 , taking in consideration the weight hanging below the disc support 79 , i.e., closing the hole 48 will cause an increase in the upward speed and opening the hole 48 will cause a lower upward speed. It is noted that the position of the hole 48 and valve 49 may also locate in other place of the disc support 79 . For example, as shown in FIG. 7A , the hole 48 and the valve 49 may locate in the center of the disc support 79 .
[0124] After arriving the roof floor 74 or the higher floor 75 , the disc support 79 is then engaged in the inclined lateral tray roller bearing system 65 through the guide guard 21 toward the door 22 . The firefighter 18 can then enter the building through exit 32 .
[0125] If necessary, this rescue device may also be used to send a person from a higher floor to a lower floor simply by decreasing the pressure difference generated by the blower 43 according to the weight of the persons 17 or firefighter 18 .
[0126] Further, in addition to a rigid tube with fixed length and size, the tube in the present invention may also be foldable and flexible.
[0127] FIGS. 8A-8E illustrate another embodiment of the present invention where the tube 80 is in a form of foldable double wall duct 46 . FIGS. 8A-8E also chronologically illustrate a procedure when a person escapes from a building using such embodiment. As shown in
[0128] FIG. 8A , the escape device includes an exterior chamber 783 attached to the building 71 and the door 22 placed at the roof floor 74 or upper floor 75 . A double wall duct 46 is folded and stored in chamber 783 , so that in case of an emergency, a person 17 can open the hatch 27 , permitting a double wall duct 46 stored in the exterior chamber 783 to be deployed, as shown in FIG. 8B .
[0129] According to the embodiment, the double wall duct 46 is a flexible structure that can be folded and stored in a chamber. It includes an inner smooth surface 81 , an outer flexible duct 61 , and air inlet or valve 40 located on the upper end of the outer flexible duct 61 . Both of the inner smooth surface 81 and the outer flexible duct 61 are made of a nonporous flexible material 15.
[0130] FIG. 8C shows the person 17 passes the door 22 , and engages the disc support 79 to the rail 33 , being ready to descend through the double wall duct 46 . The double wall duct 46 in this figure has not been fully deployed yet.
[0131] FIG. 8D shows the double wall duct 46 being fully deployed. The fully deployed double wall duct 46 reaches to approximately seven (7) feet above the ground level 77 .
[0132] After double wall duct 46 is deployed, air is pumped into the space between the inner smooth surface 81 and the outer flexible duct 61 through the air inlet 40 , thereby inflating the double wall duct 46 into a tube 80 .
[0133] FIG. 8E shows the double wall duct 46 converted to a tube 80 and several persons 17 fixed to the attachment 37 and start to descending through the inflated double wall duct 46 .
[0134] Since the door 22 is closed, the descending motion generates a lower pressure and/or vacuum pressure 41 above the disc support 79 . The air pressure below the disc support 79 remains the atmospheric pressure. Therefore, the person 17 will fall controlled by the differential pressure at a safe speed through the tube 80 . After the person 17 descending to the lower floor 76 or ground floor 77 , she may escape through the exit 32 .
[0135] FIGS. 9A-10D show another embodiment of the rescue device that may be used by firemen. According to the embodiment, a double wall conduct 46 is assembled to an extensible boom motor crane 36 . As shown in FIG. 10E , the double wall conduct 46 includes at least two hooks 52 at its lower end and a plurality of rings 19 on its outer flexible duct 61 . The plurality of rings 19 is distributed along the length of the double wall conduct 46 along the lower section thereof, so that when the lower section is folded, each hook 52 can hook to one of the rings 19 .
[0136] FIG. 10A shows the top end of the extensible boom motor crane 36 where the double walled duct 46 starts to be released when a hatch door 27 is opened. FIG. 10B shows the top end of the extensible boom motor crane 36 where the double walled duct 46 is deployed. When the double wall conduct 46 is longer than needed, it can be folded to a predetermined shorter length by flipping inside out the lower portion of the double wall conduct 46 , i.e., section 53 a shown in FIG. 10D , to a desired length, and hooking the hook 52 to the ring 19 , as shown in FIGS. 10C and 10E . Then the folded double wall conduct 46 is inflated through the inlet 40 at its lower end and forms a tube 80 with a desired length, as shown in FIG. 10D .
[0137] FIG. 10D also shows the person 17 fixed to an attachment 37 and a disc support 79 is descending from the folded inflated double wall conduct 46 . Because the double wall conduct 46 is folded at the section 53 , the diameter at this section becomes smaller than other part of the inflated double wall conduct 46 . The smaller diameter further helps decelerate the disc support 79 when it passes through the section 53 .
[0138] Now back to FIG. 9A , to rescue people in a building, the extensible boom motor crane 36 can rise to over one hundred twenty (120) feet high to attend a fire at a building 71 through window 73 . The extensible boom motor crane 36 has an upper chamber 78 and a door 22 connected to the extensible boom, where a fireman 18 supplies disc supports 79 to as many persons 17 as needed and these persons 17 enter the upper chamber 783 through the door 22 and go down the double wall duct 46 or tube 80 at a safe and controlled speed by the lesser pressure 41 at the top side of the disc support 79 and the higher pressure 42 at the bottom of the disc support 79 . The tube 80 or the inflated double wall duct 46 can extend from the window that the extensible boom motor reaches to a height of approximately seven (7) feet above the ground floor 77 . Also, if needed, the lower chamber 784 can have pressurized air delivered by the extensible boom motor crane 36 to help maintain a desired pressure to control the rate of descent. When finally the persons 17 reach the ground, they can leave the escape device through door 22 and quickly move toward exit 32 .
[0139] While embodiments have been particularly shown and described with reference to FIGS. 1A-18I , it will be understood by one of ordinary skill in the art that various changes in faun and details may be made therein without departing from the spirit and scope of example embodiments, as defined by the following claims.
DRAWING REFERENCE NUMERALS
[0140]
[0000]
12.
Wall
13.
Vacuum Pressure and/or negative pressure
14.
Positive Pressure and/or higher pressure
15.
Nonporous flexible material
16.
Frictionless material
17.
Person or Plurality of persons
18.
Fireman, Firefighter
19.
Ring
20.
Door frame
21.
Guide guard
22.
Door
24.
Two lateral trays
25.
Roller bearings
26.
Atmospheric pressure
27.
Hatch door
28.
Locking system
29.
Push button
30.
Free position
31.
Lock position
32.
Exit
33.
Rail
34.
Guides
35.
Fixing ring
36.
Extensible boom motor crane
37.
Attachment to fit a human body, harness, four point harness
38.
Buckle
39.
Belt
40.
Air inlet
41.
Lower pressure
42.
Higher pressure
43.
Blower
44.
Bag
45.
Eye bolt & Nut
46.
Double wall duct
47.
Hole, preset valve
48.
Hole
49.
Valve
50.
Controlled air flow
51.
Knob
52.
Hook
53.
Section where the tube is reduced in diameter
54.
Hose
55.
Pant
56.
Hinge center
57.
Elastic band
58.
Open
59.
Half closed
60.
Closed
61.
Flexible duct
62.
Lever
63.
Belt hook
64.
Elastic material
65.
Inclined lateral tray roller bearing system
67.
Pod slot
68.
Pod clip
69.
Clip lock
70.
Small Hole
70′.
Hole
71.
Building
72.
Entrance
73.
Window
74.
Roof floor
75.
Upper floor
76.
Lower floor
77.
Ground floor
78.
Lower chamber
783.
Upper chamber
784.
First channel
79.
Disc support, ring shaped support
80.
Tube
81.
Smooth surface
82.
Acceleration length
83.
Deceleration length
84.
No hole and/or valve length
85.
Beam
86.
Intermediate ring
87.
Lower ring
88.
Plank
89.
Swivel point
90.
Exterior sealed compartment
91.
Dome
152.
Skirt
154.
Skirt
621.
Bar
622.
Bar
623.
Hinge
624.
Hinge
626.
Lever
791.
Upper side
792.
Lower side
793.
Ring
801.
Upper space
802.
Lower space
850.
Hinge
870.
Lower ring | An escape and rescue device for a multistory building to: a) evacuate a person or persons attached to an expandable disc support with an attachment lowered from an upper level of a building through a vertical tube, by using lesser pressure at the top and a higher pressure at the bottom, using a door at the top or at the bottom to maintain pressure or by artificial air pressure, thereby permitting the fast evacuation of many people in a short time, b) use by firemen in training, c) use at amusement parks, that would teach users of rides about reliability and safety, and d) transport firemen in a fast way from the ground to the upper floors without interfering with evacuation at congested stairways of the building. | 0 |
BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to gas turbine airfoils in general, and to methods and apparatus for refurbishing gas turbine airfoils in particular.
2. Background Information
Gas turbine engines, particularly those in aircraft applications, will occasionally ingest substances (e.g., water and sand) entrained within air drawn into the engine. The substances will wear rotorblades and stator vanes (“airfoils”) located within the engine. The leading edge of an airfoil is particularly susceptible to this type of damage. Left unchecked, deformation and erosion will negatively affect the performance of the airfoil and can eventually cause irreparable damage to an airfoil. To minimize performance loss and to ensure safe operation, airfoils are periodically inspected for deformation and wear both on-wing and during regularly scheduled overhaul and maintenance. In those instances where the wear is beyond acceptable standards, the rotor blade or stator vane must be refurbished or replaced. A person of skill in the art will recognize that airfoils within a gas turbine engine, particularly fan blades within modern high-bypass ratio fan blades, are very expensive to replace. Hence, there is considerable advantage in refurbishing gas turbine airfoils when possible.
If, for example, the leading edge of a fan blade is worn beyond acceptable standards, present refurbishment methods generally require that the aircraft be taken off-line, and the fan assembly subsequently removed from the engine and disassembled so the worn airfoil can be refurbished. If the wear is within predetermined limits, the leading edge is refurbished by machining the leading edge back to or near original specifications Although refurbishing a blade using presently known techniques is preferable to replacing the blade, there are nevertheless several undesirable aspects associated with such a process. First, the aircraft is typically taken out of service thereby eliminating its revenue producing potential. Second, there is considerable labor and cost involved in removing the blade from the engine particularly when the engine is mounted on-wing. In addition, when a rotor assembly is disassembled it is sometimes necessary to perform a “run-up” test before the engine can be allowed back in service. Testing of this nature, while prudent and necessary, nevertheless also increases the cost of the repair. Third, fan blade leading edges are typically refurbished using a manual process. The accuracy of the refurbishment is important because the leading edge profile is critical to the aerodynamic performance of the airfoil, and consequent performance of the engine. Accurately refurbishing the edge by hand requires considerable skill and time and is generally considered to be a long lead-time process. This is particularly true for ultra-high bypass fan blades that have significant twist and curve.
In instances where a foreign object more substantial than water or sand (e.g., rocks, birds, etc.) is ingested into the engine and impacts a rotor blade or stator vane, quite often a nick or dent occurs too large to be accommodated by refurbishment. If the damage is within allowable standards, a blending operation can be used to repair the damage. To our knowledge, blending operations do not restore the airfoil leading edge to its original profile. In fact some practices involve removing a curved portion out of the edge to eliminate the damage. The depth of the curved portion into the airfoil causes the repaired edge to be blunter than the original edge. A person of skill in the art will recognize that a blunter edge, even one that is only slightly different, will likely have appreciable impact on the aerodynamic performance of the airfoil. Another problem with some blending operations is that they involve forming tools that are not completely guided or have only limited guidance relative to the edge to be blended. Limited guidance cutting tools are often harder to control making it harder for the operator to produce the desired leading edge profile. In addition, if used improperly, a blending tool can gouge and irreparably damage an airfoil during the repair process. For these reasons, blending tools are not well suited for edge refurbishment.
What is needed, therefore, is a method and/or an apparatus for refurbishing gas turbine airfoils that can be used on airfoils mounted within a gas turbine engine, and one that does not require considerable skill to perform or use.
DISCLOSURE OF THE INVENTION
It is, therefore, an object of the present invention to provide an apparatus and a method for refurbishing gas turbine airfoils that requires less skill than is necessary to perform some conventional refurbishment methods.
It is another object of the present invention to provide an apparatus and a method for furbishing gas turbine fan blades that can be used on engine mounted fan blades.
According to the present invention, a method for refurbishing an edge of an airfoil is provided that includes the steps of: (a) providing a portable refurbishing device having an edge shaper and airfoil positioners that positively engage the airfoil; (b) locating the edge shaper and the airfoil edge relative to one another with the positioners; and (c) moving one of the device or the airfoil relative to the other along the airfoil edge.
The present invention provides several significant advantages over the prior art of which we are aware. One of those advantages lies in the ability of the present invention to refurbish the edge of a fan blade while that fan blade is mounted within the engine. As a result, the amount of time an aircraft is out of service for fan blade refurbishment is significantly decreased. Performing the refurbishment on a mounted fan blade also eliminates the substantial cost of removing and reinstalling the engine, and the cost of testing the reassembled engine.
Another significant advantage of the present invention is that the refurbishment does not require a highly skilled operator. The positioners within the device ensure the airfoil edge is properly located relative to the edge shaper, thereby decreasing the opportunity for error, consequently facilitating the refurbishment process. The positive engagement of the positioners also helps to prevent inadvertent gouging that may occur with some prior art devices.
Another advantage of the present invention is that a method and device is provided that is designed to refurbish substantially all of the airfoil edge. Pushing the present device along the airfoil edge helps to create a continuous uniform machined surface. Hand-held blending devices are typically designed to machine small, localized areas and are not well-suited to provide a continuous machined surface. The continuous uniform surface possible with the present method and device can be shaped in agreement with the original specification geometry to ensure improved aerodynamic performance.
These and other objects, features and advantages of the present invention will become apparent in light of the detailed description of the best mode embodiment thereof, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the refurbishing device.
FIG. 2 is an exploded view of the refurbishing device.
FIG. 3 is a sectional view of the refurbishing device shown in FIGS. 1 and 5, sectioned along plane 3 — 3 as shown in FIG. 5 .
FIG. 4 is a sectional view of the refurbishing device shown in FIG. 1 sectioned along plane 4 — 4 .
FIG. 5 is a top view of the refurbishing device.
FIG. 6 is a diagrammatic enlarged view of the edge shaper.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, an airfoil edge refurbishment device 10 includes a housing 12 , an edge shaper 14 (see FIG. 2 ), positioners 16 for positively positioning an airfoil 18 (see FIGS. 3 and 4) relative to the edge shaper 14 , and a drive 20 . The housing 12 includes a channel 22 within which the airfoil edge is received and an aperture 24 (see FIG. 3) for receiving the edge shaper 14 . The aperture 24 intersects the channel 22 and allows the edge shaper 14 to be mounted at a fixed position within the channel 22 . The housing 12 is sized so that it may be hand held by an operator.
Referring to FIGS. 1 and 3 - 5 , the positioners 16 include three airfoil locator sets 26 , 28 attached to the interior side surfaces 34 of the channel 22 , and a set of base pads 32 in the base 36 of the channel 22 . The locator sets include a center locator set 26 and a pair of end locator sets 28 . The center locator set 26 includes a pair of slides 38 , 40 positioned opposite one another, and one or more biasing pads 42 extending out from one or both slides 38 , 40 in a direction toward the opposite slide 40 , 38 . The end locator sets 28 each include a pair of slides 44 , 46 positioned opposite one another, and one or more biasing pads 48 extending out from one or both slides 44 , 46 in a direction toward the opposite slide 46 , 44 . The slides 38 , 40 , 44 , 46 of each locator set are angularly disposed relative to one another in the same set. The biasing pads 42 , 48 are spring-loaded or otherwise biased to cause the airfoil 18 to be positively engaged while received within the channel 22 . In the preferred embodiment, the slides 38 , 40 , 44 , 46 and biasing pads 42 , 48 of the center and end locator sets 26 , 28 are arcuately shaped to accommodate three-dimensional curved and twisted airfoils 18 .
Referring to FIG. 4, the base pads 32 extend lengthwise along the base 36 of the channel 22 . When an airfoil 18 is engaged within the channel 22 , the base pads 32 extend lengthwise along the edge of the airfoil 18 , substantially aligned with the airfoil edge. The base pads 32 are biased (e.g., by a spring) toward the top of the channel 22 , preferably extending above the edge shaper 14 to prevent inadvertent engagement of the edge shaper 14 with the airfoil edge. The base pads 32 can be depressed toward the base 36 of the channel 22 to a position where the airfoil contact surface 50 of each base pad 32 is aligned with or below the cutting surface 52 of the fixed position edge shaper 14 , thereby exposing the edge shaper 14 to the airfoil edge. The distance 53 between the airfoil contact surfaces 50 of the base pads 32 and the cutting surface 52 of the edge shaper 14 represents the airfoil edge depth of cut per pass.
Referring to FIG. 6, the edge shaper 14 includes a rotary wheel 54 mounted on a shaft 56 . The circumferential surface profile of the rotary wheel 54 permits the airfoil edge to be refurbished substantially within original manufacturing geometric tolerances for the airfoil edge. The profile is asymmetric and includes a pressure-side machining surface 58 and a suction-side machining surface 60 that arcuately meet one another. The length of the pressure-side machining surface 58 is shorter than that of the suction-side machining surface 60 . Preferably, the pressure-side machining surface 58 is approximately one-half the length of the suction-side machining surface 60 . In the preferred embodiment, a portion of the profile of the rotary wheel 54 has a contour that follows the original cross-sectional geometry of the fan blade at the leading edge and in some cases the profile also follows a portion of the blade aft of the leading edge as well. The method by which the shaping wheel 54 removes material from the airfoil edge can be selectively chosen to suit the airfoil material at hand; e.g., a milling or an abrasive type operation.
Referring to FIG. 2, the drive 20 for the edge shaper 14 can be electrical, hydraulic, or pneumatic. An example of an acceptable drive is a commercially available variable speed electrical drive having a flexible output shaft 62 . One end of the flexible shaft 62 is connected to an electric motor 64 and the other end is connectable to a chuck 66 for holding the shaft 56 of the edge shaper 14 . The chuck 66 is attachable to the housing 12 of the refurbishing device 10 . The electric motor 64 may be mountable in a harness or other operator supported device (not shown). Alternative drives may be mounted directly to the refurbishing device housing 12 , thereby avoiding the need for flex shaft and motor separate from the chuck.
During periodic maintenance airfoils within a gas turbine engine are inspected for wear and damage. Airfoil edge wear that is beyond acceptable operating standards but still within repairable limits can be refurbished back to within acceptable standards. Nicks, dents, and other types of localized damage are distinguishable from wear and are typically caused by foreign object impacts. Airfoil edge wear is more widespread, generally extending over more than 50% of the fan blade leading edge. The present refurbishment method is described below as an “onwing” refurbishment of a fan blade. The present method and device are not limited, however, to fan blade on-wing refurbishments. As will be shown below, the present method and device provide a means by which the leading edge of a fan blade or other airfoil can be refurbished to within or very near original specifications without complicated set-up or highly skilled labor. As a result, there is considerable utility in using the present method and device to refurbish disassembled airfoils as well.
For an on-wing refurbishment, the fan blade to be refurbished is first locked into position using wedges or other means to prevent the fan stage containing the fan blade assembly from rotating. The fan blade is cleaned with a solvent to remove contaminants that may impede, interfere, or negatively affect the refurbishment process. Because fan blade leading edge wear is typically more pronounced in the middle half to three-quarters of the airfoil span, the refurbishment device 10 is placed on the fan blade near the base or tip. The fan blade is inserted into the channel 22 of the device until the edge of the airfoil contacts the contact surfaces 50 of the spring loaded base pads 32 extending out from the base 36 of the channel 22 . In this position, the base pads 32 help prevent inadvertent contact between the airfoil edge and the edge shaper 14 . The center locating slides 38 , 40 and associated biasing pads 42 locate the airfoil edge relative to edge shaper 14 . The end locating slides 44 , 46 and associated biasing pads 48 cooperate with one another to guide the airfoil 18 into and out of the center locating slides 38 , 40 , and therefore the edge shaper 14 . The operator engages the refurbishing device 10 by pushing it toward and along the edge of the fan blade. Push the refurbishing device 10 toward the edge causes the base pads 32 to depress a distance 53 below the cutting surface 52 of the edge shaper 14 , thereby exposing the edge of the airfoil to the edge shaper 14 . The refurbishment device 10 is subsequently pushed along substantially the entire span of the fan blade, refurbishing the leading edge as it goes. In some embodiments, a first guide fixture is attached to the fan blade adjacent the tip of the fan blade. In other instances, a second guide fixture is attached adjacent the base of the fan blade. Surfaces attached to the guide fixtures help transition the refurbishment device 10 into or out of engagement with the airfoil edge. The depth of cut per pass is controlled by the distance between the airfoil edge contact surfaces 50 of the base pads 32 when fully depressed and the cutting surface 52 of the edge shaper 14 . The depth of cut per pass is, therefore, predetermined and fixed as a function of the positioners 16 . This process is repeated as many times as is necessary to contour the airfoil edge back within acceptable standards. After the airfoil edge refurbishment is complete, the edge is polished and cleaned using standard practices.
Although this invention has been shown and described with respect to the detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and the scope of the invention. For example, the present method has been described in terms of an on-wing refurbishment process. The method can be used for airfoils not assembled within an engine as well. | A portable device for refurbishing an edge of an airfoil is provided that has an edge shaper and airfoil positioners that positively engage the airfoil. A method for refurbishing an edge of an airfoil is also provided that includes the steps of (a) providing the portable refurbishing device; (b) locating the edge shaper and the airfoil edge relative to one another with the positioners; and (c) moving one of the device or the airfoil relative to the other along the airfoil edge. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to improvements in the method of transiently manipulating dryer steam pressure in a paper machine during grade change.
Traditionally, steam pressure has been manipulated on the assumption that a change in the production amount of paper due to a change in dryer load varies linearly during grade change and such that the moisture percentage is changed by an appropriate amount to compensate the production amount change. For this reason, no compensation has been made for the non-linear part of the production amount change. Consequently, the moisture percentage momentarily rises above the target value in the course of grade change, causing problems in plant operation. Problems resulting from an increase in the moisture percentage include the following:
If the moisture percentage increases in the course of grade change, the paper in production may become crinkled or broken.
If the moisture percentage increases at the end of grade change, it will take a long time for the moisture percentage to return to the target value. Another problem is that the increase causes the moisture profile to deteriorate. Consequently, it will take a long time to completely change to the next type of product after grade change and therefore plant uptime is reduced.
To solve these problems, it is required to bring the moisture percentage as close as possible to the target value even during grade change. A general object of the present invention is to provide a method of manipulating steam pressure wherein a change in the production amount during grade change is precisely estimated and dryer steam pressure is manipulated so as to compensate the change in the production amount, so that the moisture percentage agrees with the target value during the grade change.
2. Description of the Prior Art
FIG. 1 is a diagrammatic view showing the configuration of a paper machine. Raw material discharged out of a headbox HB is dehydrated as the material passes through a wire part WP. Then, the material is dried out by a dryer DR and rolled round a reel RL. White water produced as the result of dehydration at the wire part WP is then received by a pit PT and fed back to the headbox HB by a fan pump PMP. Basis weight and moisture percentage are measured by a measuring instrument BM and input to a controller CMT. The controller CMT controls a stock control valve VLV according to the differences of the measured basis weight and moisture percentage from their target values, in order to adjust the inflow rate of raw material. The controller CMT also manipulates a steam pressure controller PRC to control steam pressure for drying. The component indicated by a symbol SB is a stock box where the raw material is contained.
When a grade change needs to be made, the controller CMT manipulates the stock control valve VLV to adjust the flow rate of raw material to be injected into the headbox HB and the machine speed. Furthermore, the controller CMT changes the manipulated variable of steam pressure to be output to the steam pressure controller PRC. In this case, a dead time occurs since there is a certain distance between the stock control valve VLV and the headbox HB. In addition, the system composed of the dryer DR has a large delay time constant. Control therefore must be carried out in consideration of the dead time and delay time constant when grade change is made. In the specifications of Japanese Patent Publication Nos. 11718 and 27437 of 1984, the applicant disclosed a method of steam pressure manipulation during grade change. The invention described in these publications will now be explained.
FIG. 2 is a diagrammatic view showing the configuration of a process model where the dead time and a first-order delay system are feed-forward controlled in an open loop. In this figure, the output of a feed-forward controller CON is applied to a process PRS through a hold circuit HLD. Consequently, a manipulation-caused moisture percentage change B(s) is obtained. Synthesizing the B(s) and a disturbance D(s) gives an actual moisture percentage change C(s).
Note here that the transfer functions H(s) and P(s) of the hold circuit HLD and process PRS are represented by the following formulas, respectively. H ( s ) = 1 - e - Ts s P ( s ) = Ke - Ls 1 + T 0 s
where
T=Sampling interval
T o =Time constant
L=Dead time (L=m*T, where m is 0 or a natural number)
K=Process gain.
Z-transforming the composition of these two transfer functions gives the following result: HP ( Z ) = Z [ H ( s ) * P ( s ) ] = Z [ 1 - e - Ts s * Ke - Ls 1 + T 0 s ] = K ( 1 - z - 1 ) z - m * Z [ 1 s ( 1 + T 0 s ) ] = K ( 1 - z - 1 ) z - m * Z [ 1 s - 1 s + T 0 - 1 ] = K ( 1 - z - 1 ) z - m ( 1 1 - z - 1 - 1 1 - e - T / T 0 z - 1 ) = K ( 1 - α ) z - ( m + 1 ) 1 - α z - 1
where α = e - T / T 0 .
The necessary and sufficient conditions for G(z) in FIG. 2 to be able to settle finitely in the settling time of (N+m)·T (m is a natural number) are that equations 1.1 and 1.2 hold true for a given set of values a 1 , a 2 , . . . , a N , and A 0 , according to the final-value theorem, as shown below. G ( z ) = A 0 ( 1 - α z - 1 ) { 1 + a 1 z - 1 + a 2 z - 2 + … + a N - 1 z - ( N - 1 ) ( 1.1 ) lim z -> 1 A 0 K ( 1 - α ) z - ( m + 1 ) { 1 + a 1 z - 1 + a 2 z - 2 + … + a N - 1 z - ( N - 1 ) } = 1 ( 1.2 )
From equation 1.2, we have A 0 = 1 K ( 1 - α ) ( 1 + a 1 + a 2 + … + a N - 1 )
By substituting this equation into equation 1.1, we obtain G ( z ) = 1 - az - 1 KA ( 1 - α ) { 1 + ∑ i = 1 N - 1 a i z - i }
where A=1+a l +a 2 +. . . +a N−1 .
By rearranging this equation for G(Z), we have G ( z ) = 1 - α z - 1 KA ( 1 - α ) { 1 + ∑ i = 1 N - 1 a i z - i } = 1 KA ( 1 - α ) { 1 + ( a 1 - α ) z - 1 + ( a 2 - α a 1 ) z - 2 + … + ( a N - 1 - α a N - 2 ) z - ( N - 1 ) - α a N - 1 z - N } ( 1.3 )
At this point, the following holds true. B ( z ) = G ( z ) HP ( z ) = 1 - α z - 1 KA ( 1 - α ) { 1 + ∑ i = 1 N - 1 a i z - i } * K ( 1 - α ) z - ( m + 1 ) 1 - α z - 1 = 1 A z - ( m + 1 ) { 1 + ∑ i = 1 N - 1 a i z - i } = 1 A { ∑ i = 0 N - 1 a i z - ( m + 1 + i ) }
where a 0 = 1. ( 1.4 )
Assuming a 1 =. . . =a N−1 =1 in equation 1.3, we have A=1+a 1 +. . . +a N−1 =N. Consequently, G ( z ) = 1 KA ( 1 - α ) { 1 + ( 1 - α ) z - 1 + ( 1 - α ) z - 2 + … + ( 1 - α ) z - ( N - 1 ) - α z - N } = 1 K * N { 1 1 - α + z - 1 + z - 2 + … + z - ( N - 1 ) - α 1 - α z - N } ( 1.5 )
From the equation above, we obtain B ( z ) = 1 N { ∑ i = 0 N - 1 z - ( m + i + 1 ) } ( 1.6 )
FIG. 3 illustrates the results of calculating equations 1.5 and 1.6 discussed above. The upper graph of FIG. 3 represents the transfer function G(z) of the controller CON, and the lower graph represents the moisture percentage change B(z). The horizontal axis indicates time. In the figure, the process gain K is defined as 1, and the values of N and m as 6 and 3, respectively. Thus, the method of steam pressure manipulation was prescribed according to equation 1.6, on the assumption that a change in the production amount during grade change was linear and such that the production amount change was cancelled by a change in the moisture percentage caused by steam pressure manipulation.
This means that according to FIG. 2, the actual moisture percentage C(s) is given by subtracting the manipulation-caused moisture percentage change B(s) from the disturbance D(s). Thus, control has been carried out on the assumption that the disturbance D(s) changes linearly and such that the B(s) is increased linearly from time t 0 so as to compensate the disturbance D(s).
SUMMARY OF THE INVENTION
The present invention provides a method of manipulating dryer steam pressure in a paper machine during grade change. In the method, a change in the moisture percentage is determined from a change in the production amount during grade change, dryer steam pressure is manipulated so as to cancel the change in the moisture percentage, and the production amount in the course of grade change is calculated from basis weight and machine speed before and after the grade change.
The apparatus of the present invention for manipulating the dryer steam pressure comprises a first calculation part for calculating a steam pressure manipulation change value from a steam pressure prediction target value after grade change, a second calculation part for calculating another steam pressure manipulation change value from the nonlinear part of a change in the production amount, a multiplication part to which the output of the second calculation part is input so that the input value is multiplied by a weighting factor, and an addition part for summing the outputs of the multiplication part and first calculation part.
By using the dryer steam pressure manipulation apparatus and a steam pressure manipulation method described above, moisture percentage is kept constant during grade change so that such problems as sheet break are avoided and thereby plant uptime until the type of product is changed completely after grade change is increased.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic view showing the configuration of a paper machine.
FIG. 2 is a diagrammatic view showing the configuration of a process model comprising a dead time element and a first-order delay system.
FIG. 3 is a graphical view explaining the prior art method of steam pressure manipulation.
FIG. 4 is a block diagram showing one embodiment of the present invention.
FIG. 5 is a graphical view explaining the advantageous effects of the present invention.
FIG. 6 is another graphical view explaining the advantageous effects of the present invention.
FIG. 7 is yet another graphical view explaining the advantageous effects of the present invention.
FIG. 8 is still another graphical view explaining the advantageous effects of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.
FIG. 4 is a diagrammatic view showing a calculation part for calculating the amount of change in dryer steam pressure for a grade change according to the present invention. In the figure, a numeral 1 indicates the calculation part of steam pressure manipulation change value consisting of a first calculation part 11 , a second calculation part 12 , a multiplication part for multiplying the output of the second calculation part 12 by a weighting factor, and an addition part 14 for summing the outputs of the first calculation part 11 and multiplication part 13 .
A steam pressure prediction target value and other values are input to the first calculation part 11 , where a steam pressure manipulation change value determined from a predicted value of steam pressure after grade change is calculated and output. In some cases, another steam pressure manipulation change value for correcting disturbances other than a change in the production amount is calculated and added to the former steam pressure manipulation change value, and then the resulting value is output.
A basis weight target value, machine speed target value and other values are input to the second calculation part 12 , where a steam pressure manipulation change value for correcting the nonlinear part of change in production amount during grade change is calculated and output. The multiplication part 13 multiplies the steam pressure manipulation change value by a weighting factor and outputs the resulting value. The outputs of the multiplication part 13 and first calculation part 11 are summed at the addition part 14 for output as another steam pressure manipulation change value. A value from 0 to 2.00 is used as the weighting factor.
As explained with reference to the prior art method, machine speed varies linearly during the control of grade change. The stock control valve is manipulated according to this linear change in machine speed, so that basis weight also varies linearly. In this case, a change in the production amount, i.e., the product of machine speed and basis weight, which is the main cause of a change in dryer load, is evaluated as described below.
Let us assume that basis weight before grade change is B 1 , machine speed based on the production amount before grade change is V 1 , basis weight after grade change is B 2 , and machine speed based on the production amount after grade change is V 2 . If we assume that basis weight and machine speed at the ith time of manipulation are B(i) and V(i), respectively, then B(i) and V(i) are expressed as B ( i ) = B 1 + i ( B 2 - B 1 ) N V ( i ) = V 1 + i ( V 2 - V 1 ) N
where i=0, 1, 2, . . . , N (N is the frequency of manipulation).
The production amount R(i) at this point is R ( i ) = B ( i ) V ( i ) = { B 1 + i ( B 2 - B 1 ) N } { V 1 + i ( V 2 - V 1 ) N } = i 2 N 2 ( B 2 - B 1 ) ( V 2 - V 1 ) + i N { ( B 2 - B 1 ) V 1 + B 1 ( V 2 - V 1 ) } + B 1 V 1 ( i = 0 , 1 , 2 … N ) ( 1 )
Thus, R(i) is a quadratic equation of i.
In addition, the production amount R * (i) at the ith time of manipulation when the production amount is assumed to vary linearly before and after grade change is expressed as R * ( i ) = i N ( B 2 V 2 - B 1 V 1 ) ( 2 )
The difference ΔR between equations 1 and 2 is calculated as Δ R ( i ) = R ( i ) - R * ( i ) = i 2 N 2 ( B 2 - B 1 ) ( V 2 - V 1 ) + i N { B 2 V 1 - B 1 V 1 + B 1 V 2 - B 2 V 2 } = i 2 N 2 ( B 2 - B 1 ) ( V 2 - V 1 ) - i N ( B 2 - B 1 ) ( V 2 - V 1 ) = - ( N - i ) i N 2 ( B 2 - B 1 ) ( V 2 - V 1 )
( i = 0 , 1 , 2 , … , N ) ( 3 )
Since (B 2 −B 1 )(V 2 −V 1 )<0 under normal conditions, equation 3 shown above is a parabola opening downwards and takes the maximum value of −{fraction ( 1 / 4 )}(B 2 −B 1 )(V 2 −V 1 ) when i={fraction (N/ 2 )}.
From equation 1, a change in production amount as the result of subtracting the production amount before grade change from the production amount at the ith time of manipulation is given by R ( i ) - R ( 0 ) = i 2 N 2 ( B 2 - B 1 ) ( V 2 - V 1 ) + i N { ( B 2 - B 1 ) V 1 + B 1 ( V 2 - V 1 ) } ( 4 )
where
R(i)=Production amount at the ith time of manipulation (i=0, 1, . . . ,
N (N is the frequency of output)
B 1 =Basis weight before grade change (g/m 2 )
B 2 =Basis weight after grade change (g/m 2 )
V 1 =Machine speed before grade change (m/min)
V 2 =Machine speed after grade change (m/min)
Changing equation 4 gives equation 5 below. R ( i ) - R ( 0 ) R ( 0 ) = i 2 N 2 ( B 2 B 1 - 1 ) ( V 2 V 1 - 1 ) + i N { ( B 2 B 1 - 1 ) + ( V 2 V 1 - 1 ) } ( 5 )
Now, we define two constants, one of which is a ratio of change C l in the moisture percentage due to a change in the production amount, and the other is a ratio of change C 2 in the moisture percentage due to a change in the steam pressure target value of a dryer. These constants are derived from the results of step-response testing of the stock control valve and steam pressure and given by C 1 = Δ MP 100 * ( Δ BD BD ) ( % / % ) ( 6 )
where
ΔMP=Change in pre-dryer outlet moisture percentage
ΔBD=Change in basis weight before reeling (g/m 2 )
BD=Target value of basis weight before reeling (g/m 2 )
and C 2 = Δ MP 100 * ( Δ P Pf ) (%/%) ( 7 )
ΔP=Change in dryer steam pressure (kPa)
Pf=Target value of absolute dryer steam pressure (kPa)
From equations 5 and 6 shown above, an increment D i+1 in the moisture percentage due to a change in the production amount is given by Di = 100 * C 1 R ( i ) - R ( 0 ) R ( 0 )
where i=0, 1, . . . , N−1, N.
This increment in the moisture percentage due to a change in the production amount corresponds to the disturbance D(s) shown in FIG. 2 . The moisture percentage change B(s) required for canceling the disturbance by steam pressure manipulation is calculated as described below.
Let us assume a i = D i + 1 - Di D 1 = R ( i + 1 ) - R ( i ) R ( 1 ) - R ( 0 ) ( i = 0 , 1 … , N - 1 ) .
Then, we have A = ∑ i = 0 N - 1 a i = D N D 1 = R ( N ) - R ( 0 ) R ( 1 ) - R ( 0 )
If we define the manipulated variable of steam pressure as equation 1.3 noted earlier, the change in MP due to steam pressure manipulation at each sampling time after the lapse of a dead time is derived from equation 1.4 as Change in MP = - a i A = - D i + 1 - Di D N
Consequently, assuming the value of the manipulated variable of steam pressure is given by multiplying the value defined as equation 1.3 by D N , namely G i + 1 - G i = D N K A ( 1 - α ) ( a i - α a i - 1 ) ( 8 )
where i=0, 1, . . . , N and a −1 =0, a 0 =1, a N =0, then a change in the moisture percentage due to steam pressure manipulation is - ( B i + 1 - B i ) = - a i A * D N = - ( D i + 1 - D i )
where i=0, 1, . . . , N−1. Thus, it is possible to cancel the increment in the moisture percentage due to the change in the production amount by means of steam pressure manipulation.
This means that equation 8 can be rewritten as shown below for more specific instances. Note here that coefficients C1 and C2 are given by equations 6 and 7 and the process gain K is given by K=100/Pf×C. Δ G 1 = G 1 - G 0 = D N K A ( 1 - α ) = 100 * C 1 R ( N ) - R ( 0 ) R ( 0 ) * Pf 100 * 1 C 2 A ( 1 - α ) = C 1 * Pf C 2 ( 1 - α ) * R ( 1 ) - R ( 0 ) R ( 0 ) Δ G i + 1 = G i + 1 - G i = D N K A ( 1 - α ) * ( a i - α a i - 1 ) = 100 * C 1 R ( N ) - R ( 0 ) R ( 0 ) * P f 100 * 1 C 2 A ( 1 - α ) * R ( i + 1 ) - ( α + 1 ) R ( i ) + α R ( i - 1 ) R ( 1 ) - R ( 0 ) = C 1 * P f C 2 ( 1 - α ) * R ( i + 1 ) - ( α + 1 ) R ( i ) + α R ( i - 1 ) R ( 0 ) ( i = 1 , … N - 1 ) Δ G N + 1 = G N + 1 - G N = D N K A ( 1 - α ) * ( - α a N - 1 ) = 100 * C 1 R ( N ) - R ( 0 ) R ( 0 ) * P f 100 * 1 C 2 A ( 1 - α ) * - α ( R ( N ) - R ( N - 1 ) ) R ( 1 ) - R ( 0 ) = C 1 * P f C 2 ( 1 - α ) * - α ( R ( N ) - R ( N - 1 ) ) R ( 0 )
where
ΔG i−1 =Change in pre-dryer steam pressure target value (kPa); i=0, 1, . . . , N
α=exp(−T/T 0 )
T=Manipulation period (=10 sec)
T 0 =Process time constant (sec)
In addition to the above-discussed change in the production amount, the causes of disturbance responsible for a change in the dryer load during actual grade change include:
a change in the moisture percentage at a pre-dryer inlet due to a change in the machine speed or basis weight, or due to a change in the wire retention resulting from a change in the blending of raw material or from a change in the capability of water drainage in a press process;
a change in the efficiency of drying due to a change in the blending of raw material; and
a change in the drying ability due to a change in the steam shutdown state of a dryer cylinder.
A steam pressure target value after grade change must be determined according not only to a change in the production amount but to the above-mentioned causes and other hard-to-analyze process conditions. There are some algorithms that have been devised in consideration of these factors. In the embodiment discussed here, we will use values determined by using these known algorithms as steam pressure target values after grade change. The actual manipulated variable of steam pressure is determined by summing the manipulated variable for compensating nonlinear changes in the production amount in the course of grade change and the manipulated variable determined from the steam pressure target value after grade change.
The amount of change in steam pressure for compensating for errors due to the nonlinearity of the production amount during grade change is given by Δ G 1 1 = C 1 * Pf C 2 ( 1 - α ) * ( R ( 1 ) - R * ( 1 ) ) - ( R ( 0 ) - R * ( 0 ) ) R ( 0 )
Δ G i + 1 1 = C 1 * Pf C 2 ( 1 - α ) * ( R ( i + 1 ) - R * ( i + 1 ) ) - ( α + 1 ) ( R ( i ) - R * ( i ) ) + α ( R ( i - 1 ) - R * ( i - 1 ) ) R ( 0 )
i = 1 , … , N - 1
Δ G N + 1 1 = C 1 * Pf C 2 ( 1 - α ) * - α { ( R ( N ) - R * ( N ) ) - ( R ( N - 1 ) - R * ( N - 1 ) ) } R ( 0 ) ( 9 )
Note that R(i)−R * (i) is given by equation 3 discussed earlier, and α=exp(−T/T 0 ). T denotes the period of manipulation and a value of, for example, 10 sec is used for the period.
Equation 9 is changed by using equation 3 into the following. Δ G 1 ′ = C 1 * Pf C 2 ( 1 - α ) N 2 = ( B 2 B 1 - 1 ) * ( V 2 V 1 - 1 ) { - ( N - 1 ) }
Δ G i + 1 ′ = C 1 * Pf C 2 ( 1 - α ) N 2 = ( B 2 B 1 - 1 ) * ( V 2 V 1 - 1 ) { ( 1 - α ) ( 2 i - N ) + ( 1 + α ) }
( i = 1 , 2 … , N - 1 )
Δ G N + 1 ′ = C 1 * Pf C 2 ( 1 - α ) N 2 = ( B 2 B 1 - 1 ) * ( V 2 V 1 - 1 ) { - α ( N - 1 ) } ( 10 )
Furthermore, from the steam pressure prediction target value P 2 after grade change, a steam pressure manipulation change value is determined as shown below, by using such a prior art method as the one described in the specification of Japanese Patent Publication No. 117818 of 1984. Δ G 1 2 = P 2 - P 1 A ( 1 - α ) = P 2 - P 1 1 - α * 1 N
Δ G i + 1 2 = P 2 - P 1 1 - α * ( i + 1 ) - ( α + 1 ) * i + α ( i - 1 ) N = P 2 - P 1 N ( i = 1 , 2 … , N - 1 )
Δ G N + 1 2 = P 2 - P 1 1 - α * - α N ( 11 )
where P 1 is a pre-dryer steam pressure target value (kPa) before grade change, and P 2 is a pre-dryer steam pressure target value (kPa) after grade change.
An actual steam pressure manipulation change value AGi is given by equation 12 below, where a weighting factor C 0 is introduced to the manipulated variable determined by equations 10 and 11 noted above.
Δ G i =C 0 *ΔG 1 i +ΔG 2 i ( i= 1, . . . N, N+ 1) (12)
For the weighting factor C 0 , a value from 0.0 to 2.00 is used.
As explained with reference to the prior art method, a long dead time and a large delay time constant are inherent with the manipulation of a dryer and a stock control valve. For this reason, in actual applications, steam pressure manipulation corresponding to the value given by equation 12 is carried out earlier than the starting time of grade change, by as much as the dead time involved during change in the moisture percentage caused by the usual manipulation of steam pressure.
FIG. 5 is a graphical view showing one example of control performance during grade change provided by the embodiment described here. In this example, the control performance is plotted by substituting 0.549 for C 1 in equation 6, and 0.026 for C 2 and 300 for the dryer pressure target value Pf in equation 7, and by defining the time constant T 0 as T 0 =86 sec and the variable α as α=exp(− {fraction (10/86)})= 0.890227. In addition, the basis weight, machine speed and steam pressure before grade change are defined as 101.6 g/m 2 , 680 m/min and 211 kPa, respectively. Likewise, the basis weight, machine speed and steam pressure after grade change are defined as 127.1 g/m 2 , 550 m/min and 217 kPa, respectively.
The upper graph of FIG. 5 shows a change in the manipulated variable of steam pressure during grade change. Curve 1 represents the manipulated variable (ΔG 1 i in equation 10) for compensating errors due to the nonlinearity of the production amount discussed in this embodiment; curve 2 represents the manipulated variable of steam pressure in the prior art control method; curve 3 represents the total manipulated variable (ΔG i in equation 12) in this embodiment; and curve 4 represents the production amount. Note that hereinafter, the weighting factor is defined as C 0 =1.0 in every example of control performance.
It is evident from the graph that the manipulated variable of steam pressure applied in this embodiment greatly differs from that in the prior art and that the production amount is represented as a convex curve. The lower graph of FIG. 5 illustrates changes in the basis weight and machine speed. From the graph, it is understood that both the basis weight and machine speed change linearly.
FIG. 6 is another example of control performance where a minor change is made to the conditions noted above. Note that elements identical to those of FIG. 5 are referenced alike and excluded from the explanation. In this embodiment, the basis weight, machine speed and pre-dryer steam pressure before grade change are defined as 131.05 g/m 2 , 580 m/min and 212 kPa, respectively. Likewise, the basis weight, machine speed and pre-dryer steam pressure after grade change are defined as 153.05 g/m 2 , 500 m/min and 217 kPa, respectively. From the figure, it is understood that the embodiment of FIG. 6 is similar in tendency to that of FIG. 5 .
Unlike the embodiments of FIGS. 5 and 6, the embodiments of FIGS. 7 and 8 are characterized by decreases in the production amount before and after grade change. This means that the pre-dryer steam pressure target value P 2 after grade change based on the conventional algorithm is greater than the steam pressure target value P 1 before grade change in these instances of control performance. In FIG. 7, the basis weight, machine speed and pre-dryer steam pressure before grade change are defined as 114.79 g/m 2 , 630 m/min and 262 kPa, respectively. Likewise, the basis weight, machine speed and pre-dryer steam pressure after grade change are defined as 78.13 g/m 2 , 750 m/min and 142 kPa, respectively. In FIG. 8, the basis weight, machine speed and pre-dryer steam pressure before grade change are defined as 104.4 g/m 2 , 720 m/min and 254 kPa, respectively. Likewise, the basis weight, machine speed and pre-dryer steam pressure after grade change are defined as 76.38 g/m 2 , 780 m/min and 135 kPa, respectively.
As is evident from the explanation heretofore given, the following advantageous effects are offered by the present invention.
1) A change in the moisture percentage is determined from a change in the production amount during grade change. Then, dryer steam pressure is manipulated so as to cancel this moisture percentage change. Consequently, it is possible to make the steam pressure agree with a target value by suppressing variations in the moisture percentage due to a change, in particular a nonlinear change, in the production amount. This means that it is possible to avoid such problems as sheet break, reduce the time required to completely change to another type of product after grade change, and thereby increase the efficiency of plant operation.
2) The production amount at any moment during grade change is calculated from the basis weight and machine speed measured at the moment. Consequently, it is possible to precisely determine a change in the production amount, and make the steam pressure agree with a target value by preventing variances in the moisture percentage due to a nonlinear change in the production amount.
3) A value obtained by adding a steam pressure manipulation change value calculated according to a steam pressure prediction target value after grade change to a value determined by multiplying a steam pressure manipulation change value, which is derived from the nonlinearity of change in the production amount during grade change, by a weighting factor, is used as the actual steam pressure manipulation change value.
With this strategy, it is possible to combine the manipulation method of the present invention wherein the moisture percentage is made to agree with a target value by preventing a change in the moisture percentage due to the nonlinearity of change in the production amount, with the conventional manipulation method based on a steam pressure prediction target value after grade change.
4) As the actual steam pressure manipulation change value, the method of the present invention uses a value obtained by adding a steam pressure manipulation change value, which includes another steam pressure manipulation change value determined on the assumption that the production amount in the course of grade change varies linearly, to a value determined by multiplying a second steam pressure manipulation change value, which is derived from the nonlinear part of change in the production amount during grade change, by a weighting factor.
With this strategy, it is possible to combine the manipulation method of the present invention wherein the moisture percentage is made to agree with a target value by preventing a change in the moisture percentage due to the nonlinearity of change in the production amount, with the conventional manipulation method based on the assumption that the production amount changes linearly.
5) As the weighting factor, a value no smaller than 0 but no greater than 2.0 is used.
With this strategy, it is possible to adjust the degree of contribution of a manipulation change value resulting from the nonlinearity of the production amount. In addition, setting the weighting factor to 0 provides the same manipulation change value as that of the conventional manipulation method, making it possible to prevent any sudden change in plant operation due to a change in the software used.
6) A dryer steam pressure manipulation unit used during grade change in a paper machine is composed of a first calculation part for calculating a steam pressure manipulation change value from a steam pressure prediction target value after grade change, a second calculation part for calculating another steam pressure manipulation change value from the nonlinear part of change in the production amount, a multiplication part for multiplying the output of the second calculation part by a weighting factor, and an addition part for summing the outputs of the multiplication part and first calculation part.
With this strategy, it is possible to combine the manipulation method of the present invention wherein the moisture percentage is made to agree with a target value by preventing a change in the moisture percentage due to the nonlinearity of change in the production amount, with the conventional manipulation method based on a steam pressure prediction target value after grade change.
7) A dryer steam pressure manipulation unit used during grade change in a paper machine is composed of a first calculation part for calculating a steam pressure manipulation change value including another steam pressure manipulation change value determined on the assumption that the production amount in the course of grade change varies linearly, a second calculation part for calculating yet another steam pressure manipulation change value from the nonlinear part of change in the production amount, a multiplication part for multiplying the output of the second calculation part by a weighting factor, and an addition part for summing the outputs of the multiplication part and first calculation part.
With this strategy, it is possible to combine the manipulation method of the present invention wherein the moisture percentage is made to agree with a target value by preventing a change in the moisture percentage due to the nonlinearity of change in the production amount, with the conventional manipulation method based on the assumption that the production amount changes linearly. | A method and apparatus for manipulating dryer steam pressure in a paper machine during grade change, wherein change in moisture percentage is determined from a change in production amount during grade change, dryer stream pressure is manipulated so as to cancel the change in the moisture percentage, and production amount during grade change is calculated from basis weight and machine speed before and after grade change, whereby moisture percentage is kept constant during grade chagne so that sheet breaks are avoided and downtime is reduced. | 3 |
BACKGROUND OF THE INVENTION
FIELD OF THE INVENTION
The subject invention is in the field of cotton gins and is specifically directed to a gin rib having improved wear characteristics and which is easily serviced in a minimum amount of time without requiring disassembly of the gin unit.
Conventional saw-type cotton gins employ a gin stand in which a plurality of spaced parallel saw blades are mounted for coaxial rotation with respect to each other with individual gin ribs interleaved with the saw blades so that one gin rib is positioned between adjacent saw blades to cooperate with the blades effect separation of the seed from the cotton fiber. In operation, the saw blades engage the fiber and pull it through the space between blades and their respective adjacent gin ribs with such space being of such a narrow dimension as to preclude the passage of the seeds so as to effectively separate the fiber from the seed.
The portion of each gin rib adjacent the saw blades is the area where the fiber and the seed are separated and is referred to as the ginning point. It is well known that gin ribs are subjected to excessive wear in and around the ginning point due to the friction with the seed and the fiber. Such excessive wear will result in the need for replacement of the gin ribs which is a time consuming and expensive procedure since the gin is necessarily out of operation during such procedure. One reason for the substantial amount of time required for replacing gin ribs is the fact that the clearance space between the gin ribs and their adjacent saw blades is quite small and any misalignment can result in sparks and a disastrous fire in the gin. Thus, it is essential that the gin ribs be accurately positioned when replaced and such replacement can be a tedious and time consuming procedure.
It has been previously proposed to provide sacrificial wear plates or similar members removably attached to gin ribs at the ginning point so as to avoid the expense of having to completely replace worn gin ribs. Unfortunately, many of the prior known gin ribs employing such replaceable wear members require removal of the gin ribs in order to replace the wear member. Thus, the installation of the sacrificial wear members frequently requires the total removal of the gin ribs causing substantial down time for the gin and resultant expense to the ginning operation Also, the various procedures for retaining the sacrificial wear members in the position on the gin rib must be reliable since failure of the retaining means for a sacrificial wear portion can result in substantial mechanical damage and fire in the gin itself with disastrous consequences. Unfortunately, some of the prior retention means for wear plates have not been reliable and have caused substantial gin damage.
Therefore, it is a primarily object of the present invention to provide a new and improved gin rib.
A further object of the present invention is the provision of a new and improved gin rib incorporating a sacrificial wear portion.
Another object of the present invention is a provision of a new and improved gin rib on which a sacrificial wear portion is provided in a manner so that the wear portion can easily be removed for replacement without removal of the gin rib itself from the gin.
Yet another object of the present invention is the provision of a new improved gin rib in which a sacrificial wear portion is connected to the gin rib for attachment or removal by a single clamping member which provides secure retention of the wear portion on the gin rib.
BRIEF SUMMARY OF THE INVENTION
Obtainment of the foregoing objects is enabled by the preferred embodiment of the invention which comprises a gin rib consisting of a main rib component having upper and lower ends a curved outer surface in the ginning area in which a sacrificial wear finger or plate having upper and lower ends is removably positioned. The wear prone area is provided on the arcuately curved surface in which the elongated wear finger is positioned so as to extend through the ginning point. A blind threaded bore is provided adjacent the upper end of the wear prone area for receiving a threaded machine screw extending through an unthreaded bore provided on the upper end of the wear finger. The lower extent of the wear prone area of the gin rib is defined by a cantilever retaining lip extending in cantilever manner from the gin rib component and spaced above the lower end of the wear finger. The lower end of the sacrificial wear finger is defined by a lower V-shaped portion having a thickness equal to one-half the thickness of the remainder of the sacrificial wear finger member and which is received beneath the cantilever retaining lip portion previously described. The lower V-shaped portion of the sacrificial wear finger has a V-shaped surface which matingly engages a V-shaped surface of the main rib component beneath the aforementioned cantilever retainer lip.
The upper end of the sacrificial wear finger includes a non-threaded plain bore of sufficient diameter to permit the positioning of an machine screw extended therethrough with a small amount of clearance between the non-threaded plain bore in the wear finger and the machine screw. The threads of the machine screw are threaded into the threads of the blind threaded bore of the main rib component. The upper end of the non-threaded plain bore in the wear finger communicates, with a conical countersink surface which is eccentric with respect to the axis of the plain non-threaded bore. Thus, the axis of the conical countersink portion is not coextensive with the axis of the plain unthreaded bore and is displaced a small distance toward the upper end of the sacrificial wear finger from the axis of the non-threaded bore. The head of the machine screw has a conical lower surface that is essentially parallel to the conical countersink surface in the main rib component. Consequently, the tightening of the machine screw conical surface on the machine screw head engages the conical countersink surface of the wear finger bore when the machine screw is tightened so as to forcefully cam the sacrificial wear finger downwardly toward the cantilever retaining lip portion of the main rib component so as to effectively lock both the lower end and the upper end of the sacrificial wear finger in position on the gin rib.
The upper end of the sacrificial wear finger is positioned so that the machine screw provided in the non-threaded bore of the wear finger is easily accessible from the exterior of the gin so as to facilitate an easy removal and replacement of the sacrificial wear finger when required. Such removal does not necessitate removal of the gin rib and is consequently resultant in a substantial savings of time and an increase in profitability for the operator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view illustrating the preferred embodiment of the invention installed in a typical conventional gin;
FIG. 2 is a side elevation of the preferred embodiment of the invention;
FIG. 3 is a front elevation view of the preferred embodiment;
FIG. 4 is a perspective exploded view of the preferred embodiment;
FIG. 5 is an enlarged sectional view taken along lines 5--5 of FIG. 4;
FIG. 6 is a sectional view illustrating the initial step in the positioning of the wear finger on the main rib component; and
FIG. 7 is a sectional view similar to FIG. 6 but illustrating the wear finger in a subsequent position to that of FIG. 6 locked in the retaining means of the main rib component.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the invention comprises a gin rib generally designated 8 which is positioned on a cross beam 10 in a conventional gin adjacent saw blades 9 between which such gin ribs are interleaved in well-known manner as shown in FIG. 1. The outer periphery of saw blade 9 is positioned adjacent a portion of the gin rib referred to as the ginning point and which area of the rib is subject to maximum wear.
The preferred embodiment 8 of the invention comprises a main rib component 12 having an attachment fitting 14 in its upper end area 15 and a downwardly extending lower end 16. Machine screws 11 provide a sturdy and accurate attachment of the gin rib to the cross beam 10 in a manner best shown in FIGS. 2 and 3.
The upper end of main rib component 12 is provided with an arcuate forwardly facing wear finger support surface 17 at the upper end of which a blind threaded bore 18 is provided. The wear finger or plate 20 is made of wear resistant metal or other material having a curved rear surface 22 of the same shape as surface 17 on which finger 20 is positioned. The upper end of wear finger 20 is provided with a countersunk bore 24 defining a conical surface 26. A machine screw 28 is dimensioned to be positioned in countersunk bore 24 so that the threaded portion 30 of the machine screw has a small amount of clearance 32 from bore 24 as shown in FIGS. 5 and 6. The head of machine screw 28 also has a lower conical surface 34 which faces conical surface 26.
The lower end of the wear finger of plate 20 is defined by two pointed surfaces comprising an inner pointed surface formed by flat planar surfaces 40 and 42 on a lower lock lip 44 having a thickness of approximately 50% of the entire thickness of finger 20 as shown in FIG. 4. Similarly, the upper portion of wear finger 20 at its lower end is defined by first and second surfaces 50 and 52 which intersect at an apex 53 in the middle of member 20 as shown in FIG. 4.
A cantilever retainer lip 54 formed in main rib component 12 is positioned over lower lock lip 44 and has a lower surface 56 engaging the upper surface 46 of lower lock lip 44 as shown in FIG. 6. The outer extent of cantilever retainer lip 54 is defined by a V-shaped surface having an apex 58 and surfaces 59 and 60 as shown in FIG. 4 and which is of exactly the same configuration as the surfaces 50 and 52 of finger member 20.
The sacrificial finger or wear plate 20 is installed by positioning surface 22 on curved surface 17 of the main rib component 12 with lower lock lip 44 being partially positioned beneath cantilever retainer lip 54 and countersunk bore 24 being aligned with blind threaded bore 18 in the position as shown in FIG. 6. Machine screw 28 is threaded into the blind threaded bore 18 and the lower side 34' of conical surface 34 is more closely spaced from the lower portion 26' of the conical surface 26 of finger 20 than is the upper portion of conical surface 34 with respect to the upper portion of conical portion 26. Consequently, tightening movement of machine screw 28 from the position in FIG. 6 to the position shown in FIG. 7 causes machine screw surface 34' to engage wear finger surface 26' and cam finger member 20 to the right in the direction of arrows 69 as shown in FIG. 7. The movement of finger 20 to the right causes the lower lock lip 44 to move fully under cantilever retainer lip 54 so that the lower end of finger 20 is firmly locked in place by engagement of lower end surfaces 40 and 42 of finger 20 with surfaces 46 and 48 of gin rib 12. The upper end surfaces 50 and 52 of finger 20 similarly engage outer end surfaces 59 and 60 of cantilever retainer lip 54.
Thus, it will be seen that the wear finger or plate 20 is firmly locked in position by the reaction of machine screw 28 the upper end of the wear plate and the retention of the lower end of the wear plate by the cantilever retainer lip 54. Moreover, the wear finger or plate 20 can be easily removed by simply removing machine screw 28 and pulling the finger 20 from the gin without any need for removing the main rib component 12 from the gin. Additionally, the wear finger is firmly locked in place and the chances of it becoming dislodged during operation of the gin are practically nil.
It should be understood that the spirit and scope of the invention is to be limited solely by the appended claims and that the invention may be practiced in ways that are different from the preferred embodiment of the invention. | A removable wear finger or plate is held in position on a gin rib by a machine screw on one end passing through a bore in the wear finger and an overlying cantilever retainer lip on an opposite end. The screw when tightened urges the wear finger toward the cantilever retainer lip. | 3 |
CROSS REFERENCE RELATED TO APPLICATION
The present application is a continuation of application Ser. No. 11/443,658, filed May 31, 2006, which is hereby incorporated by reference in its entirety. Application Ser. No. 11/443,658 claims the benefit of U.S. Provisional Application No. 60/689,773, filed Jun. 10, 2005.
BACKGROUND OF THE INVENTION
The present invention relates to a hinge lid aroma pack, and more particularly to a pack having aroma areas and roughened perforated areas that rub across the aroma areas when the hinge lid is opened to thereby release aroma to the consumer.
Microencapsulation is a process by which a core material is captured within a second material or shell. It is well known in the field to encapsulate aromas and flavors in shells of varying sizes so that the flavor is preserved until the rupture of the capsule by mechanical or other force. Preservation of the flavor within the capsule assures that upon release of the flavor it is as consistently strong as when it was first encapsulated. “Flavor,” “fragrance,” “aroma,” and like terms are used interchangeably herein to indicate any substance that is capable of causing an olfactory sensation.
A multitude of processes exists for manufacturing microcapsules. A variety of techniques can be utilized to produce microcapsules of varying sizes, differing resistances to rupture and alternative capsule compositions and capsule constituents. Several different encapsulation processes are disclosed in U.S. Pat. Nos. 3,516,846; 3,516,941; 3,778,383; 4,087,376; 4,089,802; 4,100,103 and 4,251,386 and British Patent Specification Nos. 1,156,725; 2,041,319 and 2,048,206. Common shell formations include the polymerization reaction of urea and formaldehyde and the polycondensation of methylated urea and aldehydes.
One manner of an aroma-releasing pack is disclosed in U.S. Pat. No. 6,612,429 where encapsulated aroma areas on the inside of the lid are contacted by retention cuts or laterally projecting fins on the innerframe when the pack is opened to thereby release aroma by rupturing the microencapsulated aroma on those areas.
SUMMARY OF THE INVENTION
Among the objects of the present invention is the provision of a hinge lid aroma pack that releases a pleasing aroma to the consumer upon opening the pack.
It is a further object of the invention that the aroma is preserved against degradation until it is released upon opening of the pack.
The objects of the invention are achieved by incorporating flavorants into microcapsules or similar flavor encapsulating materials. The encapsulated flavorants are adhered to surfaces inside the pack so that the flavorant is released upon opening of the hinge lid pack. Placement of the encapsulated flavorants is determined by consideration of frictional contact between particular surfaces of the pack. The flavorant is released through frictional contact of the encapsulating materials on the pack with other structural elements of the pack.
All of the above outlined objectives are to be understood as exemplary only and many more objectives of the invention may be gleaned from the disclosure herein. Therefore, no limiting interpretation of the objectives noted are to be understood without further reading of the entire specification and drawings included herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
Novel features and advantages of the present invention in addition to those noted above will be become apparent to persons of ordinary skill in the art from a reading of the following detailed description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which:
FIG. 1 is a perspective view of a hinge lid aroma pack with the lid open illustrating coated aroma areas and perforated panels, according to the present invention;
FIG. 2 is a front elevational view of the aroma packs shown in FIG. 1 with the lid closed and portions of the pack partially broken away to illustrate interior details;
FIG. 3 is a side elevational view of the hinge lid aroma pack of FIGS. 1 and 2 with the lid open and portions of the pack partially broken away to illustrate a coated aroma area and a cooperating perforated panel;
FIG. 4 is a side elevational view similar to FIG. 3 with the lid partially closed illustrating the perforated panel inside the lid rubbing against the coated aroma area;
FIG. 5 is a top plan view of paperboard blank for forming the aroma pack shown in FIGS. 1-4 ;
FIG. 6 is a side elevational view of an alterative hinge lid aroma pack with the perforated panel on the innerframe and the aroma coated area inside the lid; and
FIG. 7 is a perspective view of a continuous roll of material from which individual segments are cut to form the innerframe of the aroma pack of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring in more particularity to the drawings, FIGS. 1-4 illustrate a hinge lid aroma pack 10 for packaging cigarettes, for example, according to the present invention, and FIG. 5 shows a blank 12 for producing the aroma pack. Blank 12 is folded into a pack shape and glued together as is well known in the art. Pack 10 also includes an innerframe 14 , and a roll of such innerframes is shown in FIG. 7 .
Referring to FIG. 5 , blank 12 is made of cardboard or other paper stock, as is well known, and comprises a body forming portion or outerframe 16 including a front panel 18 and a back panel 20 integrally connected together by a bottom panel 22 . A right side panel 24 and a left side panel 26 are integrally connected to the front panel, and a right side panel 28 and a left side panel 30 are integrally connected to the back panel, as shown. Bottom dust flaps 31 are connected to the right and left side panels 28 , 30 .
Blank 12 also has a lid forming portion 32 including a back panel 34 and a front panel 36 integrally connected by a top panel 38 . Lid forming portion 32 also includes a reinforcing panel 40 which when reverse bent rests against front panel 36 . Front panel 36 of lid forming portion 32 includes a right side panel 42 and a left side panel 44 integrally connected to the front panel 36 of the lid forming portion.
Right and left side panels 46 , 48 , respectively, are integrally connected to back panel 34 of lid forming portion 32 . Dust flaps 50 , 52 for the lid adjacent the side panels 46 , 48 function to close the edges between top panel 38 and the side panels of the lid forming portion. The dust flaps also reinforce the top 38 of the lid.
A 45° or other appropriate angle cut line 54 extends between side panels 28 , 30 of body forming portion 16 and side panels 46 , 48 of lid forming portion 32 . Cut lines 54 merge into a hinge line 56 between the body and lid forming portions and about which the lid of the assembled cigarette pack 10 articulates relative to the body of the pack. Cut lines 54 enable such articulating to occur.
In the embodiment of the invention shown in FIGS. 1-5 , the right and left side panels 46 , 48 of the lid forming portion 32 each include a plurality of perforations 60 formed from the pack to the front of these panels. The front of each side panel 46 , 48 , as viewed in FIG. 5 , presents a roughened surface that rubs across aroma coated areas of the lid to release aroma upon opening the pack 10 , as explained more fully below.
As noted above, each pack 10 includes an innerframe 14 comprising a front panel 62 and right and left side panels 64 , 66 , positioned within the body forming portion 16 of the pack. The outer surface of the innerframe panels 64 , 66 each include an aroma coating 68 of microencapsulated flavor substances, as explained throughout the specification. Accordingly, when an assembled pack is initially opened, the perforations 60 on each side panel 46 , 48 of the lid forming portion 32 each present a roughened surface that rubs across the aroma coatings 68 on the outside of the side panels of the innerframe to thereby rupture the microencapsulated material and release aroma to the consumer. Thereafter, when the pack is closed and reopened the release of aroma continues, but to a lesser extent.
The reinforcing panel 40 of the lid forming portion 32 of the pack 10 also includes several areas of aroma coating 70 on the exposed surface of panel 40 when viewed inside the lid. Panel 40 engages the front panel 36 which positions the aroma coated areas 70 inside the lid behind the front panel. Upper edge portions 72 on the front panel 62 of innerframe 14 rub against the aroma panels when the pack is opened to thereby release flavor to the consumer by rupturing the microencapsulated aroma substances.
FIG. 6 illustrates an alternate embodiment similar to the pack of FIGS. 1-5 , but the pack 10 ′ shown in FIG. 6 includes perforations 46 on the outside surfaces of the side panels 64 , 66 of the innerframe 14 . Aroma coatings 68 are provided on the inside surface of the right and left side panels 46 , 48 of the lid forming portion 32 . Accordingly, when the pack 10 is opened the roughened perforated surface on the innerframe rubs across the aroma coatings inside the lid to thereby release the encapsulated flavors. Also, the front panel 62 of the innerframe includes outwardly extending retention cuts 74 that rub across the inside aroma surface 68 on the panels 46 , 48 of the lid to assist in rupturing the encapsulated flavor. Normally the retention cuts function to hold the lid closed, but in the present case they also function to rupture the microencapsules to thereby release aroma.
Microcapsules containing an aroma of choice are manufactured and can be obtained commercially from companies such as Arcade, Inc., Chattanooga, Tenn. Examples of potential aromas for encapsulation include peppermint and roasted/toasted aromas. However, almost any flavor oil may be encapsulated so long as it meets certain basic requirements of the technology, such as having hydrophobic qualities. A solution of polyoxymethylene urea polymer may be used to coat the flavor oils and produce the microcapsules after polymerization. The microcapsules may range in size from about 10 to about 40 micrometers in diameter.
The microcapsules may be obtained as a wet cake that can be combined with water to produce an “ink” slurry. Solvents are not utilized in combination with the cake as they may dissolve the polymer shell surrounding the microencapsulated aroma. A variety of concentrations will result in a usable ink slurry depending on the printing conditions and processes. For example, a 50% to 60% concentration of wet cake produces ink of consistency usable for gravure printing systems. In gravure printing press runs, 40 kilograms of ink at a 50% dilution concentration may yield enough ink to print approximately one million flip open boxes. Screen printing processes may also be used with microencapsulation inks.
Thus, a hinge lid pack is provided which is strategically coated with microencapsulated aroma oil ink so that frictional contact between a coated surface and other surfaces of the package occurs upon opening by the consumer. Frictional contact ruptures the microcapsules releasing a fragrant aroma to the consumer. One skilled in the art will appreciate that the present invention can be practiced by other than the described embodiments, which are presented for purposes of illustration and not limitation, and the present invention is limited only by the claims which follow.
The forgoing detailed description is primarily given for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications will become obvious to those skilled in the art upon reading this disclosure and may be made without the parting from the spirit of the invention or the scope of the appending claims. | A hinge lid pack has a lower pack outerframe and an upper lid hingedly attached to the lower pack outerframe for movement between opened and closed positions. The lid includes front, top, back and opposite sidewall portions. An innerframe is within and upwardly extends from the outerframe, and the innerframe has front and opposite sidewall portions. Microencapsulated aroma surfaces on the pack move across roughened perforations on the pack upon opening of the pack to thereby release flavor by rupturing the microcapsules. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an image forming method of forming an image on a recording material by electrophotography.
2. Description of the Prior Art
In an image forming apparatus using the electrophotographic or electrostatic recording method, an electrostatic latent image if formed on an image retainer and is developed with charged particle or toner. This apparatus is produced as a reproducing machine or printer. In order to form a multi-color image or a composed image (in which a plurality of documents or image information and a document image are superposed), the aforementioned principle is utilized in the following manner. More specifically, one cycle of (1) charging, (2) image exposure and (3) development is performed twice on the image retainer having a photoconductive layer on a conductive substrate (as is disclosed in Japanese Patent Application No. 58-184381, for example). As an alternative, there is a method of performing twice one cycle of (1) primary charging, (2) secondary charging and image exposure, (3) uniform exposure and (4) development or a method of performing twice one cycle of (1) primary charging, (2) secondary charging, (3) image exposure and (4) development (as is disclosed in Japanese Patent Application No. 58-183152), for example) by using an image retainer in which a transparent insulating layer is formed outside of a photoconductive layer. Any of these methods makes possible a multi-color development or image composition. Since the superposed image can be transferred to a transfer member by a single transfer process, the apparatus for forming the multi-color or composed image can be realized with a simple structure. A developing method therefor is required to perform the development by using a developer composed of a mixture of a nonmagnetic toner and a magnetic carrier, for example, under the conditions specified in Japanese Patent Application Nos. 58-57446 or 60-192712. This developing method belongs to a kind of magnetic brush developing method and is characterized in that the magnetic brush is not brought into contact with the image retainer, but only the toner is flown onto the latent image surface of the image retainer.
In one example of the above-specified image forming apparatus, latent images of different colors are formed by latent image forming means and are developed with toners of corresponding colors.
This multi-color image forming apparatus is represented by an apparatus in which an image retainer (which may hereinafter be called a "photosensitive member") having a photoconductive substance on a conductive substrate is irradiated with an optical beam of a laser or the like to form an electrostatic latent image. In this apparatus, the multi-color image is formed in accordance with the flow chart of FIG. 4.
FIG. 4 illustrates the variations in the surface potential of the image retainer. In FIG. 4: reference letters PH denote the exposed portion of the image retainer; letters DA denote the unexposed portion of the image retainer; letters T 1 denote the toner deposited onto the image retainer by a first development; letters T 2 denote the toner deposited to the image retainer by a second development; and letters DUP denote the rise of the potential, which has been caused by the deposition of toner T 1 to the exposed portion PH by the first development. For purpose of description, the polarity of the latent image is assumed to be positive.
(1) The image retainer is uniformly charged by a charging device to attain a constant positive surface potential E.
(2) A first image exposure is applied with an exposure light source such as a laser, a cathode ray tube or an LED so that the potential of the exposed portion PH drops in accordance with the amount of light.
(3) The electrostatic latent image thus formed is developed by a developing device to which is applied a positive bias substantially equal to the surface potential E of the unexposed portion. As a result, the positively charged toner T 1 is deposited to the exposed portion PH having a relatively lower potential to form a first toner image. The region provided with this toner image has its potential raised by DUP as a result of the deposition of the positively charged toner T 1 but not usually to the same potential as that of the unexposed portion DA.
(4) Next, the surface of the image retainer provided with the first toner image is subjected to a second charging operation to attain a uniform surface potential E no matter whether the toner T 1 is present or not.
(5) The surface of this image retainer is subjected to a second image exposure to form an electrostatic latent image.
(6) This latent image is developed like the foregoing operation (3) with the positively charged toner T 2 in a color different from that of the toner T 1 to form a second toner image.
Similar processes are accomplished a desired number of times to form the multi-color image on the image retainer. This multi-color toner image is transferred to the transfer material and is fixed by heat or under pressure to attain a multi-color recorded image. In this case, the toner and charges residing on the surface of the image retainer are cleaned so that they may be used for forming a subsequent multi-color image.
The above-specified process can be applied not only to the multi-color image but also to an apparatus for forming a recorded image by composing toner images on an image retainer and transferring them as a whole.
The following two methods exist in case various colors are to be expressed by the methods described above:
(1) The method in which toners of different colors are not directly superposed; and
(2) The method in which toners of different colors are superposed.
In the method (1), colors are generated (e.g., additive mixture of colors) in a dummy manner on the recording paper by not superposing but distributing on principle the multi-color toners T 1 and T 2 on the image retainer 1, as shown in FIG. 5A.
In the method (2), colors are generated (e.g., subtractive mixture of colors) by developing tones of different colors in a superposed manner on a toner image of a certain color, as shown in FIG. 5B.
The color reproductivity of the methods (1) and (2) usually become different even if a common toner is used. As a matter of fact, a method having the methods (1) and (2) in a compatible manner is frequently adopted because the color reproducing range can be widened to reproduce many colors.
Incidentally, if an image exposure light is absorbed when a toner image of the toner T 1 formed on an image retainer is irradiated with the image exposure light, the photoconductive layer remains in the insulated state so that its potential will not drop. Then, the toner T 2 having been developed later becomes reluctant to be deposited on that position, as shown in FIG. 5D. As a result, the color reproduced region resorting to the method (2) is highly distorted, and the color reproductivity according to the method (1) is troubled, as shown in FIG. 5C, if the positions of the images of the individual colors fail to be strictly registered.
The description thus far made corresponds to the case of inverted development. If the image exposure light is absorbed by the toner T 1 when a normal development is to be accomplished, the succeeding toner T 2 will in turn be deposited on the preceding toner T 1 in an unselective manner to cause turbidity of colors.
In order to avoid this problem, there has been proposed a method (as is disclosed in Japanese Patent Application Nos. 59-181087 or 59-181550), in which the yellow and magenta toners are developed prior to the other toners by using a laser beam of near infrared rays as the image exposure means. According to this method, the yellow image underlies another color on the image retainer but overlies another color on the transfer material. Incidentally, the yellow has a higher surface reflection than those of other colors so that the multi-color image obtained by the above-specified method has its yellow color emphasized more than necessary especially in the colors having yellow in addition to green and red. This raises a problem that the colors are remarkably difficult to control. This problem leads to a serious trouble especially in case a black color is to be expressed with the yellow, magenta and cyan toners. It is, therefore, preferable to use a special toner for expressing the black color.
Incidentally, the black toner using carbon black according to the prior art has such a wide absorption wavelength range as to substantially absorb not only a visible light but also most lights to which the photoconductive layer of the image retainer is sensitive. If the development with the black toner is accomplished prior to those with the yellow, magenta and cyan toners in case a multi-color image is to be formed with the other toners, the toners of the other colors are not developed in the positions where the Black toner is applied, as has been described hereinbefore. As a result, anything but a color having low lightness and saturation can be reproduced. If, on the contrary, the development with the black toner is accomplished after those with the other toners, the contrast of the latent image potential drops to make it reluctant to deposit the black toner. This in turn drops the black density to make the letter portions obscure and make the shades reluctant to appear in intermediate color portions.
It is certified in the experiments that the transfer efficiency is increased and the transfer material can be separated more easily from the image retainer if the image retainer is subjected to a uniform exposure prior to the transfer of the toner image to the transfer material in said processes (an exposure before transfer).
The above processes are carried out in the reversal development. Direct after the development, the electric potential at the environment of the portion on the image retainer on which the toner is attached is high, but the electric potential is lowered when it is subjected to the exposure before transfer. The exposure before transfer is, however, absorbed to a large extent by the toner at the portion where the toner is attached, so that the electric potential is not lowered sufficiently. As a result, the surface potential at this environment becomes as shown in FIG. 11.
Under such circumstances, a part of the toner T forming the toner image is separated from the original position and flown in the environment or floated in the apparatus, thereby causing the inside of the apparatus being soiled.
The above phenomenon depends on the fact that the toner T receives a strong electrostatic force in a direction parallel to the surface of the image retainer as shown in FIG. 12. Arrows show lines of electrostatic force and the positively charged toner T attached on the photoconductive layer 12 receives forces in the direction of the electrostatic force.
Such a phenomenon that a part of the toner T is separated from the original position and flown in the environment causes the image to be blurred and deteriorated in quality because the end portions or thin lines of the image become vague and the noise is formed in the screen image. Further, the soil of inside of the apparatus causes a bad influence just on the operation of the apparatus and the trouble and the stain of the image.
In the multi-color image formation or the superposition of the toner images, toner is attached on the image retainer in the form of multi-layers. However, the more the distance between the position of the toner and the surface of the image retainer the more easily the separation of the toner from the surface of the image retainer will be. As stated above, the image is deteriorated, the apparatus is soiled and th recording paper is stained by moving the toner on the image retainer to the another position by a little cause, such as electrical, optical or mechanical external forces.
Further, in said process, a portion where the toner on the image retainer is attached is subjected to each step of charging→image exposing→developing→charging→ . . . , and a portion where the toner is not attached is subjected to the charging step repeatedly. Accordingly, the electric potential at the charging start time in the charging steps after the first charging step is varied due to the fact whether the toner is attached or not, or what color toner is attached. Accordingly, the surface potential of the image retainer becomes uneven, so that the toner or carrier is attached on the non-image portion or image portion on the image retainer, thereby causing the image noise or color turbidity.
Further, it is inclined that the surface potential at the previously exposed portion becomes lower than that at the portion not exposed, because of the memory effect of the photoconductive layer on the image retainer.
As stated above, the surface potential is varied according to the hysteresis of the position. Such a method of uniformly exposing before charging may be considered to avoid the variation, such exposure light is absorbed by the toner on the image retainer, so that a sufficient effect can not be expected and the image becomes vague due to the state as shown in FIG. 12.
As a method of cleaning off the toner left on the image retainer after the aforementioned image forming process, on the other hand, the method bringing a cleaning blade or a fur brush into contact with the image retainer to mechanically scrape off the toner left after the transfer is the most effective and is generally used.
Incidentally, especially in case that process is accomplished in the reversal development, the surroundings around the positions of the image retainer, to which the toners have been deposited, take higher potentials, which are highly dispersed depending upon the positions, after the transfer. As a result, an electrostatic force acts between the image retainer and the toners left after the transfer so that it restricts the toners to invite an insufficient cleaning effect. This contaminates the inside of the reproducing machine and exerts serious adverse effects upon a next image to be formed. At the charging step, more specifically, an even potential is reluctant to establish. The latent image is disturbed at the image exposure step. The toner image is blotted at the development step. The transfer is partially missing at the transfer step. Thus, the toners left uncleaned will be accumulated to cause the above-specified phenomena more.
In order to solve this problem, there is known the method of applying a uniform exposure before the cleaning step. According to this method, the charges residing on the image retainer after the transfer are eliminated to release the restrictions of the toners. If, however, the uniform exposure light is shielded by the toners, the tential difference increases between the portions where the toners are deposited and not. This shielding effect of the toners is prominent for the black toner of higher density.
Since the portions having the toners will have their potentials retained, the effect of the uniform exposure is lost to leave the insufficient cleaning unsolved. On the other hand, the portions having no toner will have their potentials drop, and the surface potential in the neighborhood is illustrated in FIG. 11.
Accordingly, it results in problems similar that in said exposure before transfer and said exposure before charging.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide an image forming method capable of clearly recording a black color at all times and expressing the colors in a balanced manner.
This object is achieved by an image forming method which is carried out by subjecting an image retainer having a photoconductive layer to an image exposure to form a latent image, by developing this latent image with a first toner having such optical transmissivities as to substantially absorb all the light in the visible range but transmit a light in a wavelength length range of 750 nm or more, by subjecting said image retainer to an image exposure with a light having such a wavelength component as to be transmitted through said toner to form a latent image, and by developing this latent image with a second toner.
Incidentally, in the multi-color image formation of the present invention, if the toners are developed in a superposed manner on the same position of the image retainer, it is unavoidable that the contrast of the latent image potentials is gradually reduced by the charges of the toner previously developed. As a result, especially if three colors are superposed, the amount of deposition of the toner of the third color will become short. According to the principle of the subtractive mixture of colors, the black color should be able to be reproduced with the yellow, magenta and cyan toners. However, this black reproduction is made remarkably difficult by the aforementioned imbalance of the latent images.
From the reason made above, it is preferable to use the black toner in addition to the yellow, magenta and cyan toners.
In the present invention, the black color is prepared not by a single coloring agent of the carbon black but by composing a plurality of coloring agents of yellow, magenta and cyan etc. These coloring agents are so selected to have transmissive components in the invisible range so that the composed color agent of the black color obtained may transmit a light of the invisible range. Moreover, the visible light is absorbed substantially completely. These coloring agents thus obtained are used to prepare the toner, i.e., the black toner. Coloring agents other than of yellow, magenta and cyan may be used.
If this toner is used in the multi-color image forming method described hereinbefore, the black toner can be developed prior to the other toners. At this time, the light source used for the image exposure has a spectral distribution in the wavelength range transmitting the black toner but not the invisible rays. As a result, a latent image can be formed on the black toner so that the toner of another color can be developed on the black toner image.
Moreover, when the toner images superposed on the image retainer are transferred to the transfer material, the black toner is formed in the upper portion on the transfer material so that the portions of the black color can be developed clearly whereas the portions of the chromatic colors can be developed in a well balanced manner.
In the prior art, the Black toner using a coloring agent other than the carbon black is disclosed in Japanese Patent Laid-Open Nos. 48-63727, 57-119363, 58-150967 and 60-239769. In these disclosures, the use of the black toner is proposed to transfer the single-color toner image, to clean the image retainer or detect the toner density. In the present invention, second and later image exposure lights have to be transmitted through the black toner previously developed. So far as this condition is satisfied, it is possible to use the black toner disclosed in the above-specified Patent Laid-Open. In case, on the other hand, a multi-color image is to be formed with toners of yellow, magenta, cyan and black, for example, the image exposure light is required for the same reason to be transmitted through not only the black toner but also the yellow, magenta and cyan toners except the last developed one. As will be described in connection with the embodiments, what has a transmissive wavelength range commonly to all the toners is in reality a near infrared light having a wavelength of 750 nm or more. In other words, the combination of the image exposure light having an infrared component and the toner transmitting the infrared component satisfies the condition of the present invention.
It is another object of the present invention to provide a multi-color image forming method which solves such problems that the image quality is reduced because the image becomes vague due to the movement of the toner on the image retainer to the another positions and that the recording paper is soiled by the toner, thereby enhancing the transfer ability of the toner image to the transfer paper and the separation ability of the transfer paper.
It is a further object of the present invention to provide a multi-color image forming method wherein the surface potential of an image retainer becomes uniform in the charging step before image exposure irrespective of the hysteresis of each position of the image retainer and which can form an image free from the noise and the color turbidity.
It is still another object of the present invention to provide a multi-color image forming method wherein a residual toner on an image retainer is cleaned sufficiently, so that such problems that toner is scattered and the inside of an apparatus or a transfer paper is stained can be solved.
The above objects can be attained by an image forming method comprising the steps of:
forming a latent image by subjecting an image retainer having a photoconductive layer to an image exposure; forming a toner image by developing said latent image with a toner; repeating at least one time each the step of forming said latent image and the step of forming said toner image; transferring a plurality of toner images formed on said image retainer to a transfer material; and uniformly exposing said image retainer on which toner exists with a light containing a wavelength component of 750 nm or more, wherein at least one of said toner images is formed with a toner which has such a spectral transmissivity as to substantially absorb a visible light but substantially transmit a light having a wavelength of 750 nm or more. Here, the uniformly exposing step means an exposure before transfer, an exposure before charging or an exposure before cleaning.
The problems of the exposure under the existence of the toner according to the prior art are caused by the difference in the spectral transmissivities of the individual toners. When the exposures are performed from above the toners, more specifically, their effective amount reaching the image retainer depends upon the value which is obtained by integrating the product of the intensity of the light irradiated by exposure means, the transmissivities of the toners and the optical sensitivity of the image retainer with respect to the wavelength. This integrated value is small for a specific uniform exposure to raise the aforementioned problems. FIG. 8 illustrates the spectral transmissivities of the yellow, magenta and cyan toners. The spectral characteristics of this toner are measured by applying an excellently transmissive both-side tape to one side of an OHP sheet to prepare an adhesive face. The toner is uniformly applied to this adhesive face to form a substantially single toner layer, which is melted by the solvent, smoothed in the thickness of 5-10 μm, and dried to measure the spectral transmissivity. This is corrected with the spectral transmissivity of the OHP only into the spectral transmissivity of the toner. For this measurement, the spectrophotometer (HITACHI 330 type) of Hitachi, Ltd., and the wavelength is within a range of 360 to 850 nm.
If a white light, for example, is used as an exposure light before cleaning, the effective exposure amount is dependent upon the toner existing on the image retainer, as will be found in view of FIG. 8. We have conceived the present invention, noting that, if a common wavelength not to be absorbed by the individual toners is found out to effect the exposure with the light having most of its spectral distribution in that wavelength range, it is transmitted through the individual toners on the image retainer so that the photoconductive layer on the image retainer acquire a substantially equal exposure.
The prior art toner using the carbon black as its coloring agent has such a wide absorption wavelength range as to substantially absorb not only the visible light but also the light of the wavelength range to which the photoconductive layer of the image retainer is sensitive. The spectral transmissivity of this black toner is plotted by a broken curve in FIG. 8. In case a uniform exposure is accomplished after a toner image has been formed with the black toners, its light is absorbed by the black toner to raise the aforementioned problems. Therefore, the uniform exposure light is not sufficient, if it is transmitted through the yellow, magenta and cyan toners, but has to be transmitted through the black toner, too. For these transmissions, the spectral transmissivity of the black toner has to be identical to those of the other toners.
In the prior art, the black toner using coloring agents other than the carbon black is disclosed in Japanese Patent Laid-Open Nos. 48-63727, 57-119363, 58-150967 and 60-239769. In these disclosures, it has been proposed to use the aforementioned black toner so as to transfer a single-color toner image, to clean the image retainer or detect the toner density. If, in the present invention, the toner existing on the image retainer contains the black toner, this black toner naturally has to transmit the exposure light as well as the other color toners. Therefore, the black toners disclosed in the above-specified Pat. Laid-Open can be used so long as it satisfies the conditions that the transmissive wavelength range of the black toner is shared with those of the other color toners and that the exposure light has that wavelength component.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram showing a multi-color image forming apparatus using the image forming method of the present invention;
FIG. 2 is a diagram showing a laser optical system;
FIG. 3 is a section showing a developing device;
FIG. 4 presents diagrams showing the change of the surface potential on an image retainer;
FIGS. 5 A to 5 D are schematic diagrams showing the deposited states of toners on the image retainer;
FIGS. 6 and 7 are graphs illustrating, the light absorption rate of the toners according to the embodiment of the present invention;
FIG. 8 is a graph illustrating the spectral transmissivities of the toners;
FIG. 9 is a graph illustrating the radiation spectral characteristics of an infrared light emitting diode of GaAlAs;
FIG. 10 is a graph illustrating the spectral transmissivity of the combination of a halogen lamp and an infrared transmissive filter;
FIG. 11 illustrates the potential of the portion of the image retainer, on which the toner is deposited;
FIG. 12 illustrates the electrostatic force of the portion of the image retainer, on which the toner is deposited; and
FIG. 13 illustrates the spectral sensitivities of the image retainer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a multi-color image forming apparatus constructed according to one embodiment of the present invention. In FIG. 1: reference numeral 1 denotes an image retainer rotating in the direction of arrow; numeral 21 a corona charging device; letter L an image exposure light emitted from a laser optical system 26; numerals 5A, 5B, 5C and 5D developing devices having the yellow, magenta, cyan and black toners; numeral 33 a transfer electrode; numeral 34 a separation electrode; letter P sheets of recording paper; and numeral 36 a cleaning device having a fur brush 36a, a toner recovery roller 36b and a scraper 36c. The multi-color image forming apparatus thus constructed forms a multi-color image in the following manner.
The image retainer 1 is uniformly irradiated, if necessary, by an exposure lamp 20 and is then uniformly charged by the corona charging device 21 consisting of a scorotron charging electrode. Subsequently, the image retainer 1 is irradiated with the image exposure light L emitted from the laser optical system 26 in accordance with recording data. Thus, an electrostatic latent image is formed. This latent image is developed by the developing device 5D containing a first toner T 1 (i.e., the black toner).
The image retainer provided with the toner image is uniformly charged again by the corona charging device 21 and is exposed to an image exposure light L according to the recording data of another color component. The electrostatic latent image thus formed is developed by the developing device 5C containing a second toner T 2 (i.e., the cyan toner). As a result, the image retainer 1 is provided thereon with a two-color toner image with the first toner T 1 and the second toner T 2 . Subsequently, a toner T 3 (i.e., the magenta toner) and a toner T 4 (i.e., the yellow toner) are likewise developed in a superposed manner by the developing devices 5B and 5A, respectively, to form a four-color toner image on the image retainer 1.
This multi-color toner image thus obtained on the image retainer 1 is uniformly irradiated, if necessary, by an exposure lamp 30 before transfer and is then transferred to the recording paper P by the transfer electrode 33. Then, this recording paper P is separated from the image retainer 1 by the separation electrode 34 and is fixed by a fixing device 31. In this meanwhile, the image retainer 1 is uniformly exposed by an exposure lamp 35 before cleaning and is then cleaned by the cleaning device 36. The fur brush 36a of the cleaning device 36 is held out of contact with the image retainer 1 during the image formation. If the multi-color image is formed on the image retainer 1, the fur brush 36a is brought into contact with the image retainer, after the multi-color image has been transferred, so that it scrapes off the toners left after the transfer while rotating in the direction of arrow.
After the cleaning step, the fur brush 36a leaves again the image retainer 1. The toner recovery roller 36b is suitably biased, while rotating in the direction of arrow, to recover the toner T or the like from the fur brush 36a. The toner T thus recovered is further scraped off by the scraper 36c.
The laser optical system 26 of the embodiment is shown in FIG. 2. In FIG. 2: reference numeral 37 denotes a semiconductor laser diode; numeral 38 a polygon mirror; and numeral 39 an fθ lens.
FIG. 3 is a section showing the developing device 5A. In FIG. 3: reference numeral 51 denotes a housing; numeral 53 a sleeve; numeral 54 magnetic field generation means or a magnetic roll disposed in a developer carrying member, i.e., sleeve and having N and S poles; numeral 55 a layering member; numeral 56 a fixing member for fixing the layering member 55; numeral 57 a first agitation member; and numeral 58 a second agitation member. Numeral 59 denotes a sleeve cleaning member; numeral 60 a developing bias power source; numeral 18 a development region, i.e., the region in which the toner carried by the sleeve 53 is moved upon receiving the electrostatic force from the image retainer; letter T the toner; and letter D a developer. In the developing device thus constructed, the two agitation members 57 and 58 are in the form of a screw which is rotated in the directions of arrows to agitate and carry the developer. The agitation member 57 is shaped to carry the developer toward the reader with respect to the drawing sheet whereas the agitation member 58 is shaped to carry the developer apart from the reader. In order to prevent the developer from residing in the intermediate region between the two agitation members 57 and 58, there is disposed a wall 52 by which the developers at the right and left sides of the drawing sheet are exchanged at that region.
The toner supply to this developing device 5 is accomplished from this side of FIG. 3 so that the toner supplied is generally circulated into the paper surface by the agitation member 58 and out of the paper surface by the agitation member 57 until it is uniformly mixed with the carrier. However, the position of the toner supply should not be limited to the above arrangement but may be modified such that the toner is uniformly supplied to the sleeve shaft from the righthand side of FIG. 3, for example.
Thus, the developer D is sufficiently agitated and mixed and is carried in the same direction as the rotating direction of the sleeve 53 by the carrying force of the sleeve 53 and the magnetic roll 54 rotating in the directions of the arrows. The layering member 55 held by the fixing member 56 extending from the housing 52 is forced into contact with the surface of the aforementioned sleeve 53 so that it regulates the amount of the developer D carried to form a developer layer.
Incidentally, as another means for forming the developer layer when the development of the present embodiment is to be accomplished, there can be used either of the known means such as a magnetic or nonmagnetic regulating plate, which is arranged at a constant spacing from the sleeve, or a magnetic roll which is arranged in the vicinity of the sleeve.
The smaller diameter of the carrier and toner composing the developer is the more advantageous for the resolution of the image quality and the reproductivity of gradation. For example, even if the carrier of the developer layer has a small diameter of 40 microns less the impurity or granule in the developer can be eliminated automatically to form a magnetic brush having a uniform length by means of the aforementioned layering member 55 or the like. Even if, moreover, the aforementioned carrier is made to have a diameter as small as that of the toner, too, the impurity can be prevented from any inclusion to form a magnetic brush having a uniform length.
The sleeve cleaning roller 59 rotates in the direction of the arrow (as shown in FIG. 3) to scrape off the developer, which has passed through a developing region 18 and consumed the toner T, from the sleeve 53. This makes it possible to maintain the amount of the toner T to be carried to the developing region so that the developing condition is stabilized.
Next, the composition of the developer to be used in the developing method of the present embodiment will be described in the following.
Recipe of Developer
______________________________________Toner composition______________________________________polystyrene 45 wt. partspolymethyl methacrylate 44 wt. partsburrfast (charge controller) 0.2 wt. partscoloring agent 10.5 wt. parts______________________________________
This composition is mixed, blended and classified to prepare a desired toner.
(Resin-Coated) Carrier Composition:
______________________________________Core ferriteCoating Resin styrene acryl (4:6)Magnetization 27 emu/gParticle Diameter 30 micronsSpecific Gravity 5.2 g/cm.sup.3Specific Resistance 10.sup.13 ohms cm or more______________________________________
This composition is mixed, blended and classified until it is treated with hot air into a spheric carrier.
For the toner coloring agent: Auramine is used.
The known one is used as the coloring agent of the chromatic toners (e.g., yellow, magenta and cyan), as will be exemplified in the following: Benzidine Yellow G (C.I. 21090); Benzidine Yellow GR (C.I. 21100); Permanent Yellow DHG (produced by Hoechst); Brilliant Carmine 6B (C.I. 15850); Rhodamine 6G Lake (C.I. 45160); Rhodamine B Lake (C.I. 45170); Rhthalocyanine Blue non Crystal (C.I. 74160); Phthalocyanine Green (C.I. 74260); Carbon Black; Fat (Fa.) Yellow 5G; Fat Yellow 3G; Fat Red G; Fat Red HRR; Fat Red 5B; Fat Black HB; Zapon Fast; Black RE; Zapon Fast Black B; Zapon Fast Black B; Zapon Fast Blue HFL; Zapon Fast Red BB; Zapon Fast Red GE; Zapon Fast Yellow G; and Quinacrydone Red (C.I. 465000). As the coloring agent of the black toner used is prepared by mixing a plurality of kinds of coloring agents. The conditions for these coloring agents to be mixed are as follows:
(1) The absorption ranges should be compensated mutually in the visible range (360 to 700 nm); and
(2) There should be a common wavelength range in which a wavelength range of 750 nm or more can be transmitted.
Under the condition (1), the black color can be expressed. Under the condition (2), on the other hand, the light in the common wavelength range can be transmitted through the black toner. Therefore, if this light is used for the image exposure, as has been described hereinbefore, an excellent latent image can be formed.
We mixed the following pigments to measure the light absorption rate:
______________________________________(1) Pigment Yellow 97: 3.5 parts(2) Pigment Red 146: 4 parts(3) Pigment Blue 15:3 3 parts______________________________________
These pigments were mixed, melted and blended, and pulverized and classified at the following mixing ratio:
______________________________________Main resin (e.g., polyester) 100 partsParting agent (e.g., wax) 6 partsPigments 5 to 10 parts______________________________________
The measuring method of the light absorption rate is as follows:
(1) A solvent (for melting a resin, such as acetone) was added at a weight ratio of 5 times to the resin to melt the toner and the molten toner is dispersed with a stirring blade and glass beads;
(2) This molten toner was applied to have a thickness of 5 to 10 microns on the OHP sheet by a wire bar etc.; and
(3) This molten toner on the OHP sheet was dried to measure the light absorption rate by the spectrophotometer (HITACHI 330 Type) manufactured by Hitachi Ltd.
The wavelength measured was within a range of 360 to 850 nm.
Incidentally, the light absorption rate is defined by the following formula:
______________________________________log(1/T) (T: reflexibility (= amount of reflected light/amount of incident light).______________________________________
The results are plotted in FIG. 6. From this graph, it is apparent that the visible range has a substantially uniform absorption whereas the infrared range has a high transmissivity.
Next, the following pigments were likewise used to prepare a toner, whose light absorption rate was measured, as plotted in FIG. 7:
______________________________________(1) Pigment Red 57:1 6 parts(2) Pigment Blue 15:3 6 parts.______________________________________
We prepared the toners on trial with other various coloring agents and have found the fact that satisfactory results were obtained for a light absorption rate of 0.7 or preferably 0.4 or less within the main wavelength of uniform exposure For the black toner:
(1) An excellent black color is obtained for an light absorption rate of 0.8 or more over all the visible range; and
(2) The item (1) is achieved when the light absorption rate of each coloring agent has the maximum of 0.9 or more within each visible wavelength range.
If, moreover, this toner is used in the apparatus of FIG. 1 under the condition as tabulated in Table 1, a latent image of high contrast is obtained no matter what order the color is, in case the light absorption rate is 0.4 or preferably 0.2 less in the main wavelength of the image exposure. As a result, if this black toner is previously developed, a toner of another color can be superposed thereon in the case of the reversal development so that a multi-color image in excellent color balance can be attained with the black color being suitably stressed on the transfer material.
Incidentally, in the present embodiment, the semiconductor laser used for the image exposure is well known in the prior art and has a main wavelength of 780 nm. The light having this wavelength will be transmitted through not only the above-specified black toner but also the individual yellow, magenta and cyan toners.
TABLE 1______________________________________Main Scanning Rate of Laser Beam 800 m/sAux. Scanning Rate of Laser Beam 150 mm/sTime of Scanning One Image 78 nsImage Retainer Organic Photo- sensitive Member (Drum of 180 φ mm)Linear Velocity 150 mm/s (c.w.)Surface PotentialUnexposed -700 VExposed -50 VSleeve (Common)Diameter 20 mmMaterial Non-magnetic Stainless Steel (having blasted surface of 3 microns)Linear Velocity 500 mm/s (c.c.w.)Magnetic Roll (Common)Number of Poles 12Rotating Speed 1,500 r.p.m. (c.w.)Density of Magnetic Flux of 600 G (Max)Sleeve Surface (Common)Developing Gap (Common) 500 micronsBias DCYellow -600 VMagenta -600 VCyan -600 VBlack -650 VAC (Common) 3 KV.sub.p-p, 5 KHzAmount of Toner Deposited on 0.6 mg/cm.sup.2Sleeve (Common)______________________________________Writing Resolution: 16 dots/mm. Writing Level: Binary
The exposure lamp 20,30, 35 may be exemplified by a variety of light source for emitting infrared rays or a white light source covered with an infrared transmissive filter.
In the present embodiment:
(1) Infrared Light Emitting Diode (product LN 172 of Matsushita Electric Co., Ltd.)
This light emitting spectrum is plotted in the spectral distribution of FIG. 9; and
(2) Combination of Halogen Lamp and Infrared Transmissive Filter (product IR-D70 of Toshiba Glass Co., Ltd.)
The spectral transmissivity of this combination is plotted in FIG. 10. The exposure lamp 20,30,35 used belongs to the above item (1) or (2).
FIG. 13 is a graph plotting the spectral sensitivity of the image retainer.
According to the present invention, there is provided a toner and an image forming method, which can clearly record a black color at all times and express colors in a well-balanced fashion.
According to the present invention, moreover, there is provided a multi-color image forming method which can sufficiently clean the residual toner from the image retainer by the cleaning device while preventing the toner dispersion and solving the problem of blotting the inside of the apparatus and the recording paper.
According to the present invention, still moreover, the surface potential of the image retainer can be made constant irrespective of the hysteresis of each position to stably form a multi-color image having neither noise nor color turbidity.
According to the present invention, furthermore, there is provided a multi-color image forming method which can effect an excellent transfer to a sheet recording paper while solving the problem that the toner on the image retainer will shift to another position to deteriorate the image quality and blot the recording paper. | An image forming method wherein a latent image is formed by subjecting an image retainer having a photoconductive layer to a image exposure, a toner image is formed by developing the latent image with a toner, each the step of forming the latent image and the step of forming the toner image are repeated at least one time, and a plurality of toner images formed on the image retainer to a transfer material. At least one of the toner images is formed with a toner which has a spectral transmissivity as to substantially absorb a visible light but transmit a light having a wavelength of 750 nm or more. The latent image is formed by subjecting the image retainer bearing the toner image to an image exposure with a light containing a wavelength component of 750 nm or more. | 8 |
FIELD OF THE INVENTION
[0001] The present invention generally relates to an optical sensing device with multiple photodiode elements and multi-cavity Fabry-Perot ambient light filter structure to detect and convert light signal with different wavelength spectrum into electrical signal. More particularly, this invention relates to an optical sensing device capable of sensing color information of ambient light or sunlight and provides blocking of infrared (IR) light within the wavelength ranging from 700 nm to 1100 nm. The optical sensing device senses not just the ambient light brightness but also the fundamental red, green and blue color components of the ambient light.
BACKGROUND OF THE INVENTION
[0002] Ambient light sensors are now in widespread use, including cameras, camcorders, scanners, electrical microscopes, and so forth. The function of the ambient light sensors is to detect and convert ambient light brightness into electrical signal. For instance, knowing the brightness information of the ambient light, the display system brightness could be adjusted accordingly to reduce the power consumption of the backlight illumination. For most of the conventional ambient light sensor solutions, the sensor spectral response is not matched with the ideal human eye photometric response. The non-ideal ambient light sensor has a much wider spectral response range and also there are multiple peaks exhibited within the entire photodiode detection range of 400 nm to 1100 nm. Please refer to FIG. 1 , which shows a chart of spectral response regarding the wavelength spectrum of a conventional ambient light sensor.
[0003] Generally, the human eyes are capable of sensing visible light within wavelength ranging between 400 nm and 700 nm 11 . The response of the conventional ambient light sensor not only detect visible light in the range of wavelength spectrum like human eyes, but also captures infrared light with wavelength above 700 nm that human eye is unable to respond. Therefore, within the range between 700 nm and 1200 nm, two peaks 12 are produced without IR blocking according to the conventional ambient light sensor. Consequently, the inconsistency would be developed such that the human eye feels the ambient light is insufficient while, on the other hand, the conventional ambient light sensor senses sufficient ambient light. In other words, the ambient light sensor senses non-visible light that human eye is unable to response and the process for sensing non-visible light causes unnecessary backlight power consumption. For the reason, this invention provides a multi-cavity Fabry-Perot filter structure employs by utilizing the Fabry-Perot optical interference theory in order to effectively block the range from 700 nm to 1100 nm and reduce power consumption, thereby both brightness and color image processing adjustments are provided.
SUMMARY OF THE INVENTION
[0004] Therefore, it is one objective of the present invention to provide an optical sensing device. The optical sensing device comprises a substrate, a first photodiode, a second photodiode, at least one first Fabry-Perot cavity and at least one second Fabry-Perot cavity. The first photodiode and second photodiode are located on the substrate. At least one first Fabry-Perot cavity covers the first photodiode, and at least one second Fabry-Perot cavity covers the second photodiode. At least one second Fabry-Perot cavity is independent of the at least one First Fabry-Perot cavity.
[0005] Preferably, the second Fabry-Perot cavity is a single-cavity Fabry-Perot UV filter stack structure deposited on the second photodiode, and each of the first Fabry-Perot cavity has two partially reflective layers and one interferometric layer sandwiching between the two partially reflective layers.
[0006] Preferably, thicknesses of the interferometric layers are different from one another, thereby producing different spectral responses between the first Fabry-Perot cavity and the second Fabry-Perot cavity.
[0007] Preferably, the first Fabry-Perot cavity is capable of blocking the infrared (IR) light except for a wavelength spectrum that is recognizable for human eyes.
[0008] Preferably, the wavelength spectrum comprises a red-wavelength spectrum, a green-wavelength spectrum, a blue-wavelength spectrum, a cyan-wavelength spectrum, a magenta-wavelength spectrum and a yellow-wavelength spectrum.
[0009] It is another objective of the present invention to provide an optical sensing device which comprises a substrate, a plurality of first photodiodes, a second photodiode, a plurality of first Fabry-Perot cavities and at least one second Fabry-Perot cavity. The first photodiodes and the second photodiode are located the substrate. Each of the plurality of the first Fabry-Perot cavities covering one of a plurality of the first photodiodes, and each of the plurality of the first Fabry-Perot cavities has two first partially reflective layers and one first interferometric layer sandwiching between the two first partially reflective layers, and shares one of the two first partially reflective layers with a neighboring first Fabry-Perot cavity and thereby stair stacking with the neighboring first Fabry-Perot cavity. The second Fabry-Perot cavity covers the second photodiode, and has two second reflective layers and one interferometric layer sandwiching between the two second reflective layers.
[0010] Thus, the optical sensing device can effectively accomplish excellent IR blocking from non-visible light spectra and the typical transmittance of less than 2% for the entire IR range of 700 nm to 1100 nm. Furthermore, the green channel spectral response of the ambient light filter structure could well match with the spectral response of human eyes by utilizing the Fabry-Perot optical cavity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a chart of spectral response of a conventional ambient light sensor;
[0012] FIG. 2 is a cross-sectional diagram explaining an example of an optical sensing device according to an embodiment of the present invention;
[0013] FIG. 3 is a cross-sectional diagram explaining an example of the composition of a single Fabry-Perot structure according to an embodiment of the present invention;
[0014] FIG. 4 is a chart of spectral responses explaining an example of the wavelength spectrum of the ambient light filter structure with IR blocking characteristics according to an embodiment of the present invention and human eyes;
[0015] FIG. 5 is a cross-sectional diagram of an optical sensing device with a multi-cavity Fabry-Perot ambient light color filter stack structure and a single-cavity Fabry-Perot UV filter stack structure according to an embodiment of the present invention;
[0016] FIG. 6 is a cross-sectional diagram of example of an optical sensing device having two single-cavity Fabry-Perot filter stack structures according to an embodiment of the present invention;
[0017] FIG. 7 is a cross-sectional diagram of other example of an optical sensing device having two single-cavity Fabry-Perot filter stack structures according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The preferred embodiments of the present invention will be explained below with reference to the drawing.
[0019] FIG. 2 shows an example of an optical sensing device according to an embodiment of the present invention. The optical sensing device 2 comprises a substrate 21 , a first photodiode 22 , a second photodiode 23 , at least one first Fabry-Perot cavity 24 and at least one second Fabry-Perot cavity 25 . The first photodiode 22 and second photodiode 23 are located on the substrate 21 . Preferably, the substrate 21 is a silicon substrate. The first Fabry-Perot cavity 24 or the second Fabry-Perot cavity 25 are used for bandpass filtering the light with determined wavelength, for example, infrared light or recognizable light for human eyes. Preferably, each of the first Fabry-Perot cavity 24 and the second Fabry-Perot cavity 25 has two reflective layers 241 , 242 and one interferometric layer 243 sandwiching between the two partially reflective layers 241 , 242 . Preferably, the reflective layer is a silver thin film or an aluminum thin film. Preferably, the interferometric layer is a silicon nitride thin film.
[0020] The first Fabry-Perot cavity 24 and the second Fabry-Perot cavity 25 are functioned as light filters, and their spectral responses varies based on the thicknesses of the interferometric layers or the material of the reflective layer. Therefore, the first photodiode 22 combined with first Fabry-Perot cavity 24 or the second photodiode 23 combined with second Fabry-Perot cavity 25 can be used as a color sensor, an ultra violet UV sensor, an IR sensor or an ambient light sensor according to Fabry-Perot cavity structure.
[0021] FIG. 3 shows an example of a Fabry-Perot cavity for filtering green light according to an embodiment of the present invention. The embodiment of Fabry-Perot cavity located on the a silicon substrate 31 , comprises a first silicon nitride (Si3N4: 3200 ű200) thin film layer 32 , a first silver (Ag: 285 ű35) partially reflective layer 33 , a second silicon nitride (Si3N4: 920 ű50) thin film layer 34 , a second silver (Ag: 285 ű35) reflective layer 35 , and a third silicon nitride (Si3N4: 3500 ű200) thin film layer 36 . The preferred embodiment of the present invention has a P-type silicon substrate 31 which includes an array of N+ junction a photodiode element (not shown). On top of the N+/P-type photodiode, the first silicon nitride (Si3N4: 3200 ű200) thin film layer 32 is deposited on the silicon substrate 31 , the first silver (Ag: 285 ű35) partially reflective layer 33 is deposited on the first silicon nitride thin film layer 32 , the second silicon nitride (Si3N4: 920 ű50) thin film layer 34 is deposited on the first silver partially reflective layer 43 , the second silver (Ag: 285 ű35) partially reflective layer 35 is deposited on the second silicon nitride thin film layer 34 , and the third silicon nitride (Si3N4: 3500 ű200) thin film layer 36 is deposited on the second silver partially reflective layer 35 .
[0022] By way of the manufacturing process mentioned above, the single Fabry-Perot structure can be made and constitutes a simple five layers process plus the photodetector silicon substrate 31 . The conventional all dielectric thin film photometric filters require forty-two layers of thin-film coating. The first silicon nitride thin film layer 32 is a bottom spacer layer, the first silver partially reflective layer 33 is a bottom partial reflector layer, the second silicon nitride thin film layer 34 is a center interferometric dielectric layer, the second silver partially reflective layer 35 is a top partial reflector layer, and the third silicon nitride thin film layer 36 is a top moisture protective layer. The second silicon nitride thin film layer 34 is a Fabry-Perot interferometric nitride layer, for filtering a certain spectral band of light, and a dielectric material such as silicon dioxide (SiO2) or oxy-nitride may be further applied thereon. The second silicon nitride thin film layer 24 can be shaped by Plasma Enhanced Chemical Vapor Deposition (PECVD). The first silver reflective layer 33 , the second silicon nitride thin film layer 34 , and the second silver reflective layer 35 are formed the core of the Fabry-Perot optical cavity. The first silicon nitride thin film layer 32 and the third silicon nitride thin film layer 36 are to protect the first silver reflective layer 33 and the second silver partially reflective layer 35 from moisture.
[0023] The ambient light filter structure can be made by the Complementary Metal Oxide Semiconductor (CMOS) technology, the bipolar technology, and the Bi-Complementary Metal Oxide Semiconductor (BiCMOS) technology. Furthermore, combining the single Fabry-Perot ambient light filter structure with a metal three light shield layer is to provide an effective stray light rejection structure for integrated electrical circuits (the metal three light shield layer is deposited between the silicon substrate). The design of the multi-cavity Fabry-Perot ambient light filter structure is based on the 1 st order optical interference theory to provide an excellent IR blocking characteristic for wavelength of 700 nm to 1100 nm.
[0024] Next, the responses of the ambient light filter structure according to the present invention and the human eye will be explained with FIG. 4 .
[0025] As shown in FIG. 4 , the chart introduces two responses, the first response 41 is the response of the ambient light filter structure according to the present invention and the second response 42 is that of the ideal human eye. Obviously, regarding the first response 41 , the wavelength spectrum ranging from 700 nm to 1100 nm is effectively blocked by the ambient light filter structure and the response of the ambient light filter structure is proximate to the response of the ideal human eye at the range of 400 nm to 700 nm. The peak wavelength of the ambient light filter structure locates at around 555 nm 412 . The spectral response of the ambient light filter structure substantially matches the response of the human eye.
[0026] Next, an optical sensing device with a multi-cavity Fabry-Perot structure will be explained. FIG. 5 shows a cross-sectional diagram of an optical sensing device with a multi-cavity Fabry-Perot ambient light color filter stack structure and a single-cavity Fabry-Perot UV filter stack structure according to an embodiment of the present invention. The multi-cavity Fabry-Perot ambient light color filter stack structure is deposited on a photodiode array element 54 which comprises three photodiodes 51 , 52 , 53 , such as the N+/P-substrate photodiodes shown in FIG. 5 . The multi-cavity Fabry-Perot ambient light color filter stack structure comprises seven layers, they are: a first silver (Ag) partially reflective layer 511 deposited to cover the region of the first photodiode 51 ; a first silicon nitride (Si3N4) interferometric layer 512 deposited on the first silver partially reflective layer 511 ; a second silver (Ag) partially reflective layer 513 deposited the first silicon nitride interferometric layer 512 and the region of the second photodiode 52 ; a second silicon nitride (Si3N4) interferometric layer 521 deposited on the second silver partially reflective layer 513 to cover the region of the second photodiode 52 ; a third silver (Ag) partially reflective layer 522 deposited to cover both the second silicon nitride interferometric layer 521 and the region of the third photodiode 53 ; a third silicon nitride (Si3N4) interferometric layer 531 deposited on the third silver partially reflective layer 522 to cover the region of the third photodiode 53 ; and a fourth silver (Ag) partially reflective layer 532 deposited on the third silicon nitride interferometric layer 531 . The first silver partially reflective layer 511 , the first silicon nitride interferometric layer 512 , and the second silver partially reflective layer 513 constitute a first Fabry-Perot optical cavity. The second silver partially reflective layer 513 , the second silicon nitride interferometric layer 521 , and the third silver partially reflective layer 522 constitute a second Fabry-Perot optical cavity. The third silver partially reflective layer 522 , the third silicon nitride interferometric layer 531 , and the fourth silver partially reflective layer 532 constitute a third Fabry-Perot optical cavity.
[0027] It should be noted that the second silver partially reflective layer 513 extends from the region of the first photodiode 51 to the region of the second photodiode 52 ; and the third silver partially reflective layer 522 extends from the region of the second photodiode 52 to the region of the third photodiode 53 . In other words, the second sliver partially reflective layer 513 is a common Fabry-Perot reflector shared by the first photodiode 51 and the second photodiode 52 ; and the third silver partially reflective layer 522 is a common Fabry-Perot reflector shared by the second photodiode 52 and the third photodiode 53 . The multi-cavity Fabry-Perot ambient light color filter stack structure can be made as a stair stack according to the present invention. The first silicon nitride interferometric layer 512 , the second silicon nitride interferometric layer 521 , and the third silicon nitride interferometric layer 531 are the interferometric center dielectric layer of the ambient light color filter structure. The deposition thickness of each silicon nitride interferometric layer may be implemented using the modern thin film deposition equipment, such as the Plasma Enhanced Chemical Vapor Deposition, which is a well controlled thickness deposition process. The seven layers of the ambient light color filter stack structure are usually used for three-color system.
[0028] The three-color system is a three fundamental color separation that human eye can recognize such as red, green, and blue. The aforementioned region of the first photodiode 51 may be implemented for capturing blue light, with a peak value near 450 nm in the wavelength spectrum. The aforementioned region of the second photodiode 52 may be implemented for capturing green light with a peak value near 550 nm in the wavelength spectrum. The aforementioned region of the third photodiode 53 may be implemented for capturing red light with a peak value near 650 nm in the wavelength spectrum. Furthermore, this type of seven layers of the ambient light color filter structure offers a modular flexible filter stack solution (the modular Fabry-Perot filter cell is formed by two silver partially reflective layers plus a silicon nitride interferometric layer and the silicon nitride interferometric layer is placed between two silver component layers) for any additional color filtering and detection. Each additional color filter cell requires only an extra modular Fabry-Perot filter stack masking layer and silicon nitride interferometric thickness layer deposition defines a specific optical passing spectrum. The partially reflective layer such as silver deposition and mask photo patterning process is based on either lift-off or dry etching process to define the modular filter regions.
[0029] Besides the three rectangles for capturing each fundamental color by the ambient light color filter structure, they may also be implemented to capture complementary color. For example, the complementary color includes cyan, magenta, and yellow.
[0030] In FIG. 5 , the single-cavity Fabry-Perot UV filter stack structure is deposited on a photodiode 55 and comprises a first aluminum (Al) reflective layer 551 , a silicon nitride (Si3N4) interferometric layer 552 deposited on the first aluminum (Al) reflective layer 551 , and a second aluminum (Al) reflective layer 553 deposited on the silicon nitride interferometric layer 552 , and is capable of blocking the light that human eye can recognize. Therefore, photodiode 55 combined with such single-cavity Fabry-Perot UV filter stack structure can be a UV sensor.
[0031] FIG. 6 and FIG. 7 show examples of an optical sensing device having two single-cavity Fabry-Perot filter stack structures according to an embodiment of the present invention. In these examples, two single-cavity Fabry-Perot filter stack structures can share a reflective layer. In FIG. 6 , the aluminum (Al) reflective layer 631 , the silicon nitride thin film layer 632 , and the silver reflective layer 633 are formed the core of the first Fabry-Perot optical cavity, and the aluminum reflective layer 641 , the silicon nitride thin film layer 642 , and the aluminum reflective layer 631 are formed the core of the second Fabry-Perot optical cavity, it means that the aluminum reflective layer 631 is shared by two single-cavity Fabry-Perot filter stack structures. Therefore, the photodiode 61 combined with first Fabry-Perot optical cavity can be functioned as an ambient sensor, and the photodiode 62 combined with second Fabry-Perot optical cavity can be functioned as a UV sensor.
[0032] In other example as shown in FIG. 7 , the aluminum (Al) reflective layer 731 , the silicon nitride thin film layer 732 , and the aluminum reflective layer 733 are formed the core of the first Fabry-Perot optical cavity, and the aluminum reflective layer 733 , the silicon nitride thin film layer 741 , and the aluminum reflective layer 742 are formed the core of the first Fabry-Perot optical cavity. Therefore, the photodiode 71 combined with first Fabry-Perot optical cavity can be functioned as an ambient sensor, and the photodiode 72 combined with second Fabry-Perot optical cavity can be functioned as a UV sensor.
[0033] In summation of the description above, the present invention of multi-cavity Fabry-Perot filter stack filter structure is novel and useful and definite enhances the performance over the conventional CMOS polymer based RGB filter and further complies with the patent application requirements and is submitted to the Patent and Trademark Office for review and granting of the commensurate patent rights. | An optical sensing device with multiple photodiode elements and multi-cavity Fabry-Perot ambient light filter structure to detect and convert light signal with different wavelength spectrum into electrical signal. In one embodiment, the optical sensing device capable of sensing color information of ambient light or sunlight and provides blocking of infrared (IR) light within the wavelength ranging from 700 nm to 1100 nm. Preferably, the optical sensing device senses not just the ambient light brightness but also the fundamental red, green and blue color components of the ambient light. | 6 |
This application is a Continuation-In-Part of application Ser. No. 08/910,835, filed Aug. 13, 1997, which is now abandoned.
TECHNICAL FIELD
The invention relates, in general, to an expandable support member, and, in particular, to an internal locking device for telescopic tube sections.
BACKGROUND OF THE INVENTION
There are many forms of telescoping tube locking devices for apparatus like paint easels, telescopes, cameras, and other optical devices. Typically the locking devices use a clamp and bolting device, spring loaded pins and holes, wing nut operated clamps, threaded collar clamps, internal threaded studs, and resilient washers that require individual leg section rotation. Some of these devices do not allow adjustable extension of the legs. Others require external protrusions and parts that can fall off and become lost.
Accordingly, given the foregoing backgrounds relating to telescopic apparatus, it is one purpose of this invention to provide an internal locking device that sequentially unlocks multiple tube or leg sections by actuating a single push rod to retract the legs to a telescope close position. The legs are extended by pulling and do not require a release mechanism.
SUMMARY OF THE INVENTION
According to principles of the present invention in a preferred embodiment, this invention corrects the problems described above by providing a simple single push rod actuated locking device that will sequentially, from a proximal to a distal end, release the leg or tube locks between multiple tube sections. The spring-loaded push rod extends partially out from the proximal end of each telescopic tube. Consequently, there are no other protrusions at each tube section interface. The push rod activates the proximal tube lock clamping means and the remaining upper tube sections are released as each upper end of a tube section contacts an internal release mechanism. The locking device parts are similar in shape, but are smaller for each succeedingly smaller diameter tube section.
Other objects, advantages, and capabilities of the present invention will become more apparent as the description proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a side elevation view of the present telescoping leg invention.
FIG. 2 is an exploded perspective view of a first embodiment of the invention.
FIG. 3 is a perspective view of an alternate spring/lock for the first embodiment.
FIG. 4A is a side section view of the first embodiment.
FIG. 4B is a section view taken along lines 4B of FIG. 4A.
FIG. 5 is an exploded perspective view of a second embodiment of the present invention.
FIG. 6 is a side cut-away section view of the second embodiment.
FIG. 7 is a front elevation of a telescoping music stand.
FIG. 8A is a partial section view of a preferred embodiment for the foot of the telescoping leg.
FIG. 8B is a bottom view of the preferred embodiment for the foot of the telescoping leg.
FIG. 9A is a partial section and front elevation of a preferred embodiment of the telescoping legs as used with a tripod for a camera mount or easel.
FIG. 9B is a partial section and side elevation view of the telescopic legs for the camera mount or easel.
FIG. 9C is a partial section view of the middle leg taken along lines 9C--9C of FIG. 9A.
FIG. 10 is an exploded perspective view of an embodiment of the telescopic leg.
FIG. 11 is a side section view of the embodiment taken along lines 11--11 of FIG. 10.
FIG. 12 is a side elevation of the release block of the embodiment of FIG. 10.
FIG. 13 is an exploded perspective view of a second embodiment of the telescopic leg and clamping means.
FIG. 14 is an exploded perspective view of a preferred embodiment of the telescopic leg and clamping means.
FIG. 15 is a side section view taken along lines 15--15 of FIG. 13.
FIG. 16 is a side section view taken along line 16--16 of FIG. 14.
FIG. 17 is an enlarged section view from FIG. 16.
DETAILED DESCRIPTION OF THE INVENTION
The inventive tube locking device will be described as it can be used in a tripod. A typical telescoping leg tripod 10 containing the inventive internal locking device is illustrated in FIG. 1. This tripod could be a platform for a camera, telescope, painter's easel or other device. This tripod, as shown, has three leg sections 15, 20, 25 but it could have more or less. One of the novel features of the invention is shown as the end of push rods 30 and 45 on front leg 35 and the back leg 40 respectively. The push rods are movable rods within the legs that release an internal locking element to telescope the legs to a closed position, as will be described below.
FIGS. 2 and 4 illustrate the first embodiment of the telescoping leg 35 elements. Within the foot 50 is push rod 30 that when pushed to the left (in FIGS. 2 and 4A) as at arrow 55, engages and moves release block 60. Pin 65 is captured within aperture 70 in plastic glide 75 after glide 75 is inserted up through leg aperture 80. Compression spring 85 within release block 60 restores the push rod 30 to its original position when the push rod is released. Plastic insert 87 eliminates metal-to-metal contact between leg sections 15, 20 and 25. FIG. 4A illustrates the assembled parts inserted within cut-away section 89 of leg section 25.
When the push rod 30 is not pushed as shown in FIG. 4A, the top 90 of pin 65 is forced against the inner wall of leg section 20 by the compression spring 85 in conjunction with any force that pushes on leg section 25, thereby locking the two sections in a fixed position. That position can be from the fully extended position, as in FIG. 1, or fully enclosed and any position in between. Pushing push rod 30 as at arrow 55 causes release block 60 to move to the left, disengaging top 90 of pin 65 from the inner wall 20 and the whole leg section 25 slides to the left until the end 95 of leg section 25 contacts and pushes the second release block 100, disengaging second pin 105 from the inner wall of top leg section 15. This view also shows a second spring 110 which is compressed between the inside face of release block 100 and a second plastic glide 115.
It can be seen that each leg section part is similar in shape and function, but is a larger size for each larger leg section, e.g., block 100 and pin 105 are larger than block 60 and pin 90. It is also obvious that pushing on push rod 30 sequentially releases each leg section.
FIG. 3 is a special embodiment for pin 65 and glide 75 utilizing a flat spring pin 120 which is inserted within a rectangular aperture 125 thereby acting as a bending spring to restore release block to the right (FIG. 4) when push rod 30 is released. This would eliminate the need for springs 85 and 110 and pin 65 in FIGS. 2 and 4A.
FIGS. 5 and 6 illustrate a second embodiment using a ramp and ball type leg locking device 130. Exploded view of FIG. 5 shows an upper leg section 15 and a middle leg section 20 and plastic insert 87. The release block 135 is notched to accept two balls 140 which rest on ramp 145 as shown on FIG. 6. Spring 150 pushes the release block 135 to the right as to arrow 155 so that ball 140 is compressed between the inner surface of leg section 15 and inclined ramp 145 which, in turn, rests on the edges of the inclined cut edges 160 of leg section 20. In this condition, leg sections 15 and 20 are fixed. When leg section end 95 pushes against release block 135 compressing spring 150, the balls 140 are released from compression between leg section 15 and ramp 145 allowing leg section 20 to slide within leg section 15. In this embodiment, plastic glide 165 serves as a spring 150 stop and also acts as a bearing surface between the inner leg section 20 and outer leg section 15. A similar leg locking device 170 is partially illustrated between leg sections 20 and 25. The leg locking device 170 would be released as previously described by a push rod 30 within leg section 25. This is a preferred embodiment over the FIGS. 1-3 device since the end 90 of the pins 65 on FIGS. 1-3 can wear and not grip the leg section whereas the balls of this invention will wear evenly and always grip. FIGS. 2 and 4 show flat sides on each leg at 171 which add stiffness to the legs and could allow multiple legs to be closer together on a tripod in the folded position.
The pins 65 or 120 and the balls 140, in addition to locking the telescoping action, also force the leg 20 against the angled sides 171 (or other concave shape) thereby stabilizing angular displacement, i.e. keeping the leg sections parallel. The pins or balls can also be replaced by any other movable pivoting cam device, and the release blocks can have other configurations as well.
FIG. 7 illustrates another use for the telescopic tube, i.e., as a collapsible music stand 175 having three sections 180, 185 and 190 with push rod 195 at the bottom. This stand could also be inverted and have the push rod at the top.
FIGS. 8A and B disclose an option to the push rod actuator 200 which in this case has a slidable release 205 which uses a pin 210 to connect to push rod 30. When release 205 is moved in direction 215, push rod 30 moves about 1/8" in the same direction since the pin 210 travels in short slot 220. End cap 225 supports push rod 30 within aperture 230. This release could be actuated with a person's toe, thereby eliminating the need to bend over to collapse the legs.
FIGS. 9A-C illustrate the use of the automatic telescopic legs connected to a tripod head 300 which can support either a painter's easel or a camera mount. FIG. 9A illustrates the two outer legs 305, 310 and center leg 315. The outer legs 305,310 are attached to leg ends 320,325 which in turn are pivotally attached to axle 330. Axle 330 also supports clamp 335. A support arm 340 is slidably attached to the clamp and can connect to an artist's easel or a camera mount.
Left leg 305 having two telescopic sections is shown in the open position and pushrod 345 and pushrod head 350 are in an upward position as shown by arrow 355. This is due to the compression spring 85 (FIG. 2) bearing against the bottom (not shown) of pushrod 345. The pushrod 345 is restrained by axle 330 and there is a small gap at 360. In this open position, the legs will lock as previously described and seen in FIGS. 2-6.
In contrast, right leg 310 is in the closed position and a leg 360 of pushrod head 365 contacts the axle 330 and forces pushrod 370 down as in arrow 375 and the leg locking devices are released and the legs can be retracted.
FIG. 9B illustrates the right leg 310 in the folded position where axle 330 engages the leg 360 of pushrod head 365.
FIG. 9C illustrates the middle leg 315 in cross section wherein this pushrod 380 is depressed by an eccentric portion 385 of clamp 335 bearing on pushrod head 390 when the middle leg is in the folded (closed) position and sliding support arm 340 is parallel to leg as shown. The middle leg telescopic sections can then be retracted within each other. The phantom lines of FIG. 9C illustrate the middle leg 315 in the open position. In this position, the pushrod 380 is moved up so that there is a gap 395 under pushrod head 390. The pushrod is forced up by spring 85 (FIG. 2) as shown by arrow 400, creating the gap 395 between pushrod head 390 and middle leg insert 405.
The push rod heads on each of the legs are accessible for manual operation when the tripod is in the open position by pushing with a finger.
FIGS. 10, 11 and 12 illustrate a first embodiment of the telescopic leg. The components of the release apparatus 1100 consist of the following parts: metal ramp insert 1105 sets over ramp cutout 1107 on fixed ramp block 1155; release block 1120 has slot 1122 for pin 1130 and aperture 1132 for release rod 1135 which is retained by screw 1137; cantilever ramp section 1115 provides a friction for sliding against tube section 1138 and acts as a stop against plastic insert 1160 (FIG. 11) for the fully extended leg position; spring loaded cantilever latch section 1110 locks into leg tube 1138 at notch cutout 1140; and compression spring 1125 presses against ramp block 1155 to push release block 1120 away, forcing roller 1130 up ramp, thereby locking tube 1138 in extended position. Plastic insert 1160 reduces sliding friction, eliminates metal-to-metal contact and stops fully extended inner leg section.
FIG. 11 illustrates the push rod assembly consisting of the push-button 1145 and release rod 1135 which attach within a distal, or bottom portion of leg tube 1138 and outer leg tube 1165. By pushing button 1145 in direction shown by arrow 1120 the release block 1120 is moved in the same direction thereby disengaging roller 1130 from the inner surface of outer leg 1165. This permits inner leg 1138 to slide to the left until the button 1145 is released, at which time the leg is again locked in position. Release 1120 also pushes on next leg release block when button 1145 is pushed. If the button 1145 is not pushed, the next section remains locked even with this section fully retracted. Button 1145 can be toe-operated. The spring 1125 restores release rod 1135, release block 1120 and button 1145 to their original positions.
FIGS. 13 and 15 illustrate another embodiment of telescopic leg release assembly 1200. Release block 1205 has a slot 1207 that retains roller 1210. Release block 1205 is fixed by screw 1215 to release rod 1220. Release block 1205 sets over ramp block 1222 and rests on flats 1240 and 1245. Compression spring 1260 pushes release block 1205 to right forcing pin 1210 up ramp so it locks against outer leg 1275. The outer leg 1275 surrounds leg 1270 (FIG. 15). Metal-to-metal contact of leg sections is eliminated and outer leg friction is reduced by optional upper plastic glide 1225 and lower plastic glide 1250.
FIGS. 14 and 16 illustrate the preferred embodiment which is similar to FIGS. 13 and 15 except there is a cutout 1230 in a proximal or upper portion of inner leg 1280 that contains ramp block 1222. There is also a bottom glide 1281 and a bottom aperture 1285 in leg 1280. The ramp block 1222 has a raised section 1282 that engages a slot 1283 when located within tube 1280. Raised section 1282 also acts as a stop when leg is fully extended. Optional glide 1225, if used, also acts as a stop. Tabs on the bottom of ramp block 1222 engage the sides of a square or rectangular hole 1285 to keep ramp block 1222 from moving side to side and binding the release block 1205 that straddles the ramp block 1222.
An advantage of the tube sections 1280 and 1275, having angled sides or concave internal surfaces, is that these angled surfaces lock the legs together when the roller 1210 engages the outer tube section. Ramp 1222 and the inner tube 1280 is forced down into the angled side of the outer tube 1275 (FIG. 16).
It should be noted that springs 1260 (FIGS. 13, 15 and 16) are not needed if the smaller diameter leg sections 1270 and 1280 are in the bottom of the tripod, i.e. gravity locks the release block 1205 and roller 1230 to the leg section 1275.
FIG. 17 shows the details of the tabs 1284 within the rectangular hole 1286.
FIGS. 13 and 14 operate in the same manner as FIGS. 10-12 but the release block and ramp lock are configured differently as is the plastic glide.
The advantages of having the automatic leg releases at the top are that they are easier to reach than at the bottom as in FIGS. 2-6 and the bottom leg sections can be sealed to prevent dirt and water from entering the legs.
While the present invention has been described by reference to specific embodiments, it will be apparent that other alternative embodiments and methods of implementation or modification may be employed without departing from the true spirit and scope of the invention. | A locking device for multiple section telescope tubes that locks the telescoping tubes in any position of extension and releases the leg sections sequentially from the bottom up by depressing a push rod. The push rod releases a pin or ball that clamps the internal surface of an outer leg to the surface of an inner leg, thereby preventing an inner leg from sliding within the outer leg. The device can be used on any telescoping device. For example, the locking device may be used with tripods for cameras, painter's easels, telescopes, and other optical instruments, as a single multi-section stand for music, microphones, light stands, canes, walking sticks, flagpoles, umbrellas, handles, tent poles, or for devices such as radio antennae or pointing devices. | 5 |
CROSS-REFERENCE TO CO-PENDING APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/071,262, filed Jan. 13, 1998, which is hereby incorporated herein by reference in its entirety.
BACKGROUND
The invention relates to radio networks, that are networks in which units wirelessly exchange information by way of radio signals. In particular, radio networks in which the air interface applies frequency hopping to spread the signal over a wide spectrum are considered. The problem addressed is the multiple access of different units on a common, frequency hopping channel.
The system considered is based on a frequency hopping (FH) system, different aspects of which are described in U.S. patent application Ser. Nos. 08/685,069; 08/932,911; and 08/932,244; as well as U.S. Provisional Application No. 60/109,692, filed on Nov. 24, 1998 in the name of J. Haartsen which are all hereby incorporated herein by reference. In this system, a channel is defined as a frequency hop sequence which is a pseudo-random number (PN) sequence determined by the identity of one of the units participating on the channel, called the master. The phase in the sequence is determined by a master clock associated with the master. As the master clock progresses, the channel hops from radio frequency (RF) hop frequency to RF hop frequency at the clock rate. All other units participating on the channel, called slaves, are synchronized to the FH scheme by using the same FH sequence and same clock as used by the master. The channel shared between the master and the one or more slaves is called a piconet.
At connection setup, the master parameters that are required to maintain FH synchronization are transferred from the master to the slave. A strict Time Division Duplex (TDD) scheme is adhered to: time slots (“slots”) in which traffic is transferred from master to slave and slots in which traffic is transferred from slave to master, alternate at the hopping rate. Preferably, a high hopping rate is used in order to obtain immunity against interferers that share the spectrum. A high hopping rate results in short slots and small packets.
The master controls the access on the channel. A distributed access method, like carrier-sense multiple access, is not useable due to the fast hopping of the channel; the dwell time on a RF hop frequency is too short to carry out an effective contention-based access scheme. On the other hand, reserved access schemes like TDMA are not suitable for packet-switched data connections. Therefore, a polling scheme is used which is entirely controlled by the master of the piconet. At any moment in time, a master may select any of the slaves participating on the channel to send data to in the master-to-slave slot. However, only the slave addressed by the master in this master-to-slave slot may respond in the succeeding slave-to-master slot.
In this scheme, the master selects a slave in the master-to-slave slot to send data to and from which it can receive data. As a result, collisions between slaves that want to send information to the master at the same time are prevented. When the master sends information to slave X, this implicitly means that slave X may respond in the next slave-to-master slot. The slave is implicitly polled by the master. If the master has no data to send, it may send a specific ‘poll’ packet to give the slave a chance to respond. A poll packet is a very short packet carrying no data.
The addressing scheme in the system is carried out as follows. Each unit has a unique identity which is, for example, derived from the 48-bit IEEE 802 addressing space. The identity of the master is used to form the FH sequence used by the channel in the piconet. Each packet is preceded by a preamble which is also derived from the master identity. This preamble is used by all the units participating in the piconet to identify whether there is a packet present in the slot, and if so whether the packet belongs to this piconet. Since many uncoordinated frequency hopping piconets may be co-located, occasionally they may happen to land on the same hop frequency. The preamble prevents the users in one piconet from accepting packets belonging to another piconet. The master address therefore identifies the piconet (or channel) and can be regarded as a channel identifier.
To distinguish between the different participants on the piconet, a short length Medium Access Control (MAC) address is used which is temporarily allocated by the master to the slave when the slave is connected to the piconet. The MAC address is located in the header of the packet. The master uses the proper MAC address to address a slave. The size of the MAC address is preferably small in order to minimize the overhead in the packet header. As was mentioned before, the system preferably uses a fast hopping rate. As a result, the packet can only be short and the amount of overhead (including the MAC address) must be minimized. However, the use of only a short-length MAC address limits the number of slaves that can simultaneously participate on the channel.
Slaves that do not have to exchange a great deal of information can be placed in a low power mode called HOLD. When the slave is in the HOLD mode, it does not participate on the channel. It neither transmits nor receives data, but it does keep its clock running (so that it remains synchronized to the FH channel), and it retains its MAC address. At the conclusion of a HOLD interval (the duration of which is agreed upon by both the master and the slave prior to entering the HOLD mode), the slave leaves the HOLD mode and participates on the channel as before.
Units that want to remain locked to the channel can enter the HOLD mode to save power consumption. However, since they keep their MAC addresses, units that rarely participate on the channel deny access to the channel to other units since the MAC address space is limited. This inefficient use of the MAC addresses is more of a problem in those described FH systems in which the MAC address is short (to minimize overhead), resulting in only a few slaves being able to participate on the channel.
SUMMARY
It is therefore an object of the present invention to provide techniques for keeping units synchronized to the channel in a piconet without requiring them to retain their MAC addresses.
The foregoing and other objects are achieved in apparatuses and methods of operating a system comprising a wireless master unit and one or more wireless slave units, wherein each of the one or more wireless slave units has a unique identifier. In accordance with one aspect of the invention, a wireless slave unit may be in a so-called PARK mode, in which it is not associated with a temporary address (e.g., a MAC address described in the BACKGROUND section). In order to page a parked wireless slave unit, a paging beacon packet is broadcast to, and received in, each of the one or more wireless slave units at fixed intervals during a master-to-slave time slot. Each wireless slave unit, determines whether the received paging beacon packet includes the unique identifier belonging to the wireless slave unit. If it does, then the wireless slave unit retrieves a temporary address from the paging beacon packet, and transmits a response to the wireless master unit during a subsequent slave-to-master time slot.
In another aspect of the invention, the wireless slave unit can determine whether a subsequent traffic packet from the wireless master unit includes the temporary address and, if so, respond by transmitting a response to the wireless master unit during another subsequent slave-to-master time slot.
In yet another aspect of the invention, the paging beacon packet is a type of beacon packet, wherein beacon packets have a header portion that includes a predefined temporary address that is never assigned to any of the one or more wireless slave units in the system.
In still another aspect of the invention, parked wireless slave units are offered an opportunity to request access to the piconet. This is accomplished by defining a series of time slots comprising alternating occurrences of a master-to-slave time slot and a slave-to-master time slot, wherein each of the slave-to-master time slots comprises a plurality of slave-to-master sub-slots. Depending on the embodiment, the number of sub-slots per slave-to-master time slot may be any integer greater than or equal to 1. Furthermore, a unique response number is allocated to each of the one or more wireless slave units. A polling beacon packet is broadcast by the master unit to each of the one or more wireless slave units at fixed intervals during a master-to-slave time slot. Receipt of the polling beacon packet by a wireless unit indicates an opportunity to request access to the piconet. Accordingly, if a wireless unit desires to access the piconet, it transmits a packet to the wireless master unit during a slave-to-master sub-slot that occurs N slave-to-master sub-slots after the polling beacon packet, wherein N is a function of the unique response number of the at least one or more wireless slave units.
In yet another aspect of the invention, the master unit is not required to give each of the wireless units an opportunity to respond to the polling beacon packet. To accommodate this possibility, a slave unit detects whether any master activity occurred in the master-to-slave time slot immediately preceding the slave-to-master sub-slot that occurs N slave-to master sub-slots after the polling beacon packet, and if so, transmits the packet to the wireless master unit only if no master activity was detected in the master-to-slave time slot immediately preceding the slave-to-master sub-slot that occurs N slave-to-master sub-slots after the polling beacon packet.
In still another aspect of the invention the wireless master unit receives the response packet from the at least one of the one or more wireless slave units, and determines which of the one or more wireless slave units transmitted the packet by determining which slave-to-master sub-slot the packet was received in, relative to the master-to-slave time slot during which the polling beacon packet was broadcast.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and advantages of the invention will be understood by reading the following detailed description in conjunction with the drawings in which:
FIG. 1 is a timing diagram of an exemplary air interface in accordance with one aspect of the invention;
FIG. 2 is a diagram of an exemplary packet format for use on the air interface in accordance with one aspect of the invention;
FIG. 3 schematically depicts an exemplary addressing scheme for use with the air interface in accordance with one aspect of the invention;
FIG. 4 is a timing diagram illustrating beacon transmission and park wake-up in accordance with one aspect of the invention;
FIG. 5 is a timing diagram illustrating the paging of a parked slave A, in accordance with one aspect of the invention;
FIG. 6 is a timing diagram illustrating a parked slave's access resolution with immediate master action, in accordance with one aspect of the invention; and
FIG. 7 is a timing diagram illustrating a parked slave's access resolution with deferred master action, in accordance with one aspect of the invention.
DETAILED DESCRIPTION
An overview of various aspects of the invention will first be presented, followed by an even more detailed description.
Overview
A method is described in which units remain synchronized to the frequency hopping channel without owning a MAC address. These units are in a new mode referred to herein as PARK mode. The channel identifier is used to initially communicate between the piconet master and parked slaves. When a parked slave wants to become active, it indicates this to the master, at which time the master allocates this slave a free, temporary MAC address. Once active, the slave can participate in the piconet, and can occasionally be put on HOLD for short time periods keeping its MAC address. For longer periods of inactivity, the slave can enter the PARK mode, giving up its MAC address in the process, thereby freeing up the MAC address for use by a different slave.
To support the PARK mode, the master transmits a broadcast packet at fixed intervals, which operates as a kind of beacon. The broadcast packet is identified by the all-zero MAC address. All slaves in PARK mode always wake up to read the beacon. If the master wants a parked slave to become active, it issues a paging message in the payload of the beacon packet. This paging message includes the full 48-bit identity of the slave and the temporary MAC address to be used by this slave. Only the slave that was paged is allowed to respond in the next slave-to-master slot.
A different scheme is used to permit parked slaves to access the channel without being paged. When the slave enters the PARK mode, it is allocated a response number that determines when the parked slave is allowed to respond without being explicitly/individually paged. The slaves are allowed in the slave-to-master slot which are preferably (but not required to be) divided into a plurality of slave-to-master sub-slots for this purpose. In the exemplary embodiment described herein, the number of slave-to-master sub-slots in each slave-to-master slot is two, and these slave-to-master sub-slots are therefore referred to herein as half-slots. It should be understood that alternative embodiments can easily be derived from the description of the exemplary embodiment by substituting the term “slave-to-master sub-slots” in place of the term “half slots”, thereby indicating that there may be more or even fewer than two of such slots.
Continuing now with the exemplary embodiment, in which the slave-to-master sub-slots are half slots, a parked slave with response number N is allowed to send a message in the Nth slave-to-master half slot counted from the beacon packet, provided no master activity has been detected in the master-to-slave slot precisely preceding this response slot. The response message will consist of the channel identifier (preamble) only. The position of the response message with respect to the beacon packet tells the master which parked slave is requesting access. The master may grant the access by directly sending a (broadcast) paging message mentioned before in the next master-to-slave slot. Alternatively, the master may wait until all parked slaves have had a chance to respond, and then make a decision regarding which slave to address. Parked slaves that have requested access but are not granted access should keep listening to the channel for (broadcast) paging messages, because the master may grant access to the requesting slaves sequentially before the next beacon occasion. Parked slaves that have not issued an access request can enter the sleep mode until the next beacon occasion.
To enter a PARK mode, the slave unit must first be registered with the piconet master. This registration couples the identity of the parked slave to the response number (which should always be kept as low as possible). The master should regularly do registration updates so that slaves that were formerly parked but have left the coverage area, can be de-registered so that the response number can be reused for another parked slave. Parked slaves with high priority should be issued lower response numbers than parked slaves having lower priority.
If the master is already engaged with another (active) slave at the designated time for a beacon transmission, it does not have to abort its operations. Instead it may defer the beacon transmission to the next available master-to-slave slot. The parked units will wake up and read the channel identifier to adjust their clocks. Units not desiring access can then return to sleep until the next beacon event. Units that desire access remain awake and wait until the beacon packet indeed passes along.
The invention distinguishes between active slaves in a high-power mode and inactive slaves in a low-power mode. By reserving the MAC address for the active slaves only, a large number of inactive slaves can be supported without much overhead on the channel. For bursty data traffic, active and inactive slaves can be swapped (reusing the MAC addresses) based on their traffic requirements. In this way, the number of slaves virtually connected to the channel can be much larger than indicated by the MAC address.
More Detailed Description
The various features of the invention will now be described in even greater detail with respect to the figures, in which like parts are identified with the same reference characters. In order to facilitate a better understanding of the invention, the focus of the discussion is on the air interface, the types of communications that take place between master and slave units, and on the various ways that master and slave units respond to receipt of various types of packets. Those having ordinary skill in this art should have no trouble designing and making operable systems based on the functional description presented herein. Such systems may include, for example, programmable equipment that executes program instructions created in accordance with the principles set forth herein, and stored in any of a variety of computer readable storage media, including but not limited to Random Access Memory (RAM), magnetic storage media (e.g., hard and/or floppy disks) and optical storage media (e.g., Compact Disc (CD) Read Only Storage (ROM)).
Private radio communications require the deployment of unlicenced bands. Presently there is not much unlicenced radio spectrum that is globally available. One band, the Industrial, Scientific, Medical (ISM) band at 2.4 Ghz is an exception; it is available worldwide although the precise operational channels may differ per country.
The usage of the ISM band is restricted to radio systems applying signal spreading. In this way, uncoordinated systems spread their interference. Each system is given a fair chance to make use of the spectrum and no single system can dominate the usage. A cost-effective spreading method is the use of frequency-hop spreading, that is the ISM band is divided into a number, M, of RF hop frequencies and the channel hops from one hop frequency to the next according to a pseudo-random hop sequence.
The hopping rate is restricted to a minimum of 2.5 hops/s. The choice of the hopping rate depends on a number of criteria. To obtain the optimal interference immunity (through interference diversity and statistical multiplexing) a high hopping rate is desired. If a hop is lost due to interference, only a small burst of the communications is lost. This is especially advantageous for voice communications which can overcome only short periods of high bit error rates without noticeable effects. For data communications, the choice of a suitable hopping rate depends on the choice of access scheme. For an ethernet-like access scheme, like carrier-sense multiple access (CSMA, also known as “listen before talk”), a slow hopping is desired for optimal contention resolution.
If voice and data have to be combined, a high hopping rate must be used for voice transmission, requiring a different access scheme for the data. Instead of CSMA/CA (CSMA/ collision avoidance), a polling scheme is used in which a central unit, the master, controls the access to the channel. The system has been designed in which all units are peer units in principle, but when establishing a connection between the units, one of the units will be the master whereas the other units will become slaves. The master-slave relation is only valid for the duration of the connection. The master can set up a piconet. The piconet uses a FH channel at a high hopping rate. A strict TDD scheme is used in which the master-to-slave and slave-to-master transmissions alternate at the hopping rate. The FH sequence is determined by the master identity, the phase in the sequence is determined by the master system clock. At connection setup, the master transfers its identity and clock to all slaves. By using this single identity and clock, all users (master and slaves) are synchronized and can follow the hopping channel. FIG. 1 is a timing diagram of an exemplary FH-TDD channel as meant in this disclosure. Each packet 101 used on the channel is uniquely identified by a preamble. This is, for example, a 64-bit unique word with good cross- and auto-correlation properties. The preamble is derived from the master identity. A packet 101 has to have the proper preamble before it is accepted by the participating units. The preamble can be regarded as the channel identifier since it identifies the packets belonging to the channel. A packet 101 has a typical format as shown in FIG. 2 . In the example, the preamble 201 is followed by a header 203 which is followed by a payload 205 .
Each unit has a unique identity, which is for example derived from the 48-bit IEEE 802 address space. This identity is only used at the time of call set up for the purpose of paging a unit. During the connection, a temporary MAC address is used. This can be a much smaller address, for example 3 bits, since it only has to distinguish between the participating units. This MAC address is part of the header 203 . The addressing is schematically shown in greater detail in FIG. 3 . Each unit has a unique identity (wake-up identifier) 301 which is used during the paging process. A channel identifier 307 is derived from the master identity 303 . Finally, a MAC address 305 in the header identifies the units participating in the same piconet. The unit identities 301 and the derived channel identifiers 307 are unique. The MAC address 305 is only allocated temporarily and is valid during the connection. The all-zero MAC address is reserved for broadcast messages. To avoid collisions on the channel, the master and slave strictly follow the TDD scheme: the master is only allowed to transmit in the master-to-slave slot, and the slaves are only allowed to transmit in the slave-to-master slot. In order to avoid collisions between slaves, the only slave that is allowed to transmit is that slave which was addressed with its MAC address 305 by the master in the preceding master-to-slave slot. This is called polling: a slave can only respond when polled/addressed by the master. This polling can occur implicitly, that is by sending a packet containing traffic in the payload addressed to the proper slave; or explicitly by using a special POLL packet without payload but addressed to the proper slave.
The MAC address 305 is much smaller than the unit identity 301 . This will reduce the overhead in the packet because the (Forward Error Correction (FEC) encoded) MAC address 305 is present in each packet header. However, this limits the amount of units that can participate in a piconet. In particular, units that want to be attached to a piconet but not actively involved in communications (like sleeping participants) need a MAC address 305 which is inefficiently used. Therefore, a method is now described that allows units to remain parked to the piconet channel, without their being assigned a MAC address 305 .
Units that have been in connection with the piconet have all the information needed to remain synchronized to the piconet, that is, they have the master identity 303 and the master clock. From the master identity 303 , the FH sequence and the channel identifier 307 (packet preamble) can be derived; from the clock, the phase in the FH sequence can be derived. Occasionally, a unit has to listen to the master transmission to adjust its clock to account for clock drifts. We now distinguish between four different modes of operation: STANDBY, ACTIVE, HOLD, and PARK. In STANDBY, a unit is not attached to any other device. It periodically wakes up to listen to page messages. The page message must include the unit's identity. A unit in ACTIVE mode uses the master identity 303 and clock to keep synchrony to the FH channel and to extract the proper packets by filtering the packets with the proper preamble. In addition, it has a MAC address 305 to be recognized by the master. Units that for a short moment can be put inactive will enter the HOLD mode. In this mode, the slave sleeps for a pre-determined period of time, after which it becomes active again. During the sleep mode, the slave cannot get access to the channel, nor can it be reached by the master. A slave in HOLD mode retains its MAC address 305 . A slave that can be put inactive for a longer amount of time will enter the PARK mode. In this mode, a slave gives up the MAC address 305 , thereby making that MAC address 305 available for assignment to another slave unit. The slave in PARK mode wakes up periodically to listen for the channel identifier 307 to adjust its clock to account for drifts.
To let parked units participate again, a special access method has to be carried out. A master can activate a parked unit by paging it. To facilitate this paging, the master transmits a broadcast message at regular intervals (hereinafter also referred to as a beacon). During this beacon event, the parked unit can become active again, so in principle, the parked slave only has to wake up during the beacons. The broadcast message is identified by a predefined MAC address that is never assigned to any of the slaves. In the exemplary embodiment, the predefined MAC address is the all-zero MAC address. To activate a parked slave, the master pages this slave by including the slave's identity 301 in the payload 205 of the broadcast packet 101 . In addition, the payload 205 includes the (temporary) MAC address 305 to be used by the parked slave. A slave paged in this manner is allowed to respond directly in the slave-to-master slot following. The slave also retains the assigned MAC address 305 , so that it will recognize future packets directed to it by the master unit.
For the parked slave to get access to the channel, a different approach is required. Again, collisions between different parked slaves that desire access simultaneously, must be avoided. The following scheme is used. When entering the PARK mode, the parked unit is allocated a response number by the master. This response number is used by the parked slave to determine when it is allowed to transmit a channel access request to the master. Channel requests are only allowed when the beacon indicates that requests can be sent. Instead of polling each parked slave separately, a broadcast poll is transmitted indicating to the parked units that they are allowed to request access. However, the response number determines in which slot a parked slave is allowed to transmit an access request. In another aspect of the invention, in order to speed up the request procedure, the slave-to-master slots may be divided into a plurality of slave-to-master sub-slots. For purposes of illustration, the exemplary embodiment utilizes two half slots per slave-to-master slot. However, alternative embodiments may use more or fewer than two half slots per slave-to-master slot.
For a request, the parked slave only has to transmit the channel identifier 307 (which is just a preamble 201 ). The identifier and its position with respect to the broadcast poll indicates to the master which parked slave is requesting access. It can then send a page message to this slave (including the slave's identity 301 and a MAC address 305 ) to activate the slave.
An example will further clarify the PARK mode procedures. FIG. 4 is a timing diagram showing how a broadcast message 401 (e.g., packet that includes a header 203 containing a zero MAC address) is sent at regular intervals to act like a beacon. Units in PARK mode only wake up during the beacon (or alternatively during only every N beacons in order to reduce power consumption). Referring now to FIG. 5, when a master wants to activate parked slave A, it sends a page message 501 including A's identity 301 and a temporary MAC address ‘A’. In the slave-to-master slot following the page message 501 , slave A can respond 503 as an activated slave using the just allocated MAC address ‘A’.
For a parked slave to gain access, the broadcast poll is used. FIGS. 6 and 7 are timing diagrams showing several ways of using the broadcast poll. Assume that there are three parked units A, B and C, and that these units have received response numbers 1 to 3 , respectively. The broadcast poll 601 induces all parked units to respond if they want access. The parked units respond in the appropriate half slots according to their response number and send a short packet 603 -A, 603 -B containing the preamble only (channel identifier 307 ). In FIG. 6, the master does not await the response from C, but instead directly pages 605 unit A. Unit A's response 607 is transmitted in the very next slave-to-master slot.
In FIG. 7, the master transmits a broadcast poll 701 , thereby making it possible for the parked units to respond if they want access. In this example, the master first collects all slave responses by waiting until all parked units have had a chance to respond (although unit C has no desire to access the channel), before it makes a decision and pages one of the units. In this example, units A and B respond with their respective short packets 703 -A, 703 -B containing the channel identifier 307 in the first and second half slots to occur after the broadcast poll 701 . No short packet is transmitted in the third half slot however, because of unit C's lack of interest in accessing the channel. To accommodate for the case in FIG. 6, the parked units are only allowed to respond if in the master-to-slave slot immediately preceding their respond slot, no master activity is detected. For example, in the case of FIG. 6, unit C cannot respond in the first half slot in hop k+3 because of the presence of a page 605 in hop k+2.
Units that require access, but are not granted access right away, should keep listening to the master transmissions. Since a request has been received by the master, it may page the corresponding parked slave at any time, not only at the beacon instances.
In another aspect of the invention, a priority scheme can be defined by giving units with higher priority a lower response number. In all cases, it is preferred that the response numbers should be kept as low as possible to allow for a fast access. Therefore, the master should check to ensure that units that are registered as parked are still locked to the channel. This can, for example, be accomplished by having the master page a parked unit periodically, preferably with a long time interval between pages. When the parked unit responds, it is activated and may be placed back into the PARK mode. This registration check only takes a few slots (say 4 or 5 slots) and only has to be carried out infrequently (e.g., every 15-30 minutes), so the overhead is minimal. If a parked slave does not respond to the page, it should be removed from the PARK list, so that its response number can be reused by another unit.
In addition to the support for low-power modes, that is for units that want to remain locked to the channel without actually participating on the channel, the described techniques can be used to support a much larger number of users than indicated by the MAC address. This can advantageously be used for slaves supporting data traffic. Data traffic is bursty: when a message arrives, the master and slave need to exchange some packets to convey the information, but in-between messages there may be a long idle time. By properly scheduling the traffic, slaves that are in the idle time between the messages are placed in the PARK mode, and slaves that need to exchange messages are in the ACTIVE mode. As soon as a message has been transmitted, the slave is put in the PARK mode, thereby giving up its MAC address. A parked slave can then be activated and this same MAC address reused for information exchange. That is, active and inactive slaves are swapped all the time between the ACTIVE mode and the PARK mode depending on their traffic requirements. In this way, the amount of slaves that virtually participate on the channel is much larger than indicated by the small MAC address.
The invention has been described with reference to a particular embodiment. However, it will be readily apparent to those skilled in the art that it is possible to embody the invention in specific forms other than those of the preferred embodiment described above. This may be done without departing from the spirit of the invention. The preferred embodiment is merely illustrative and should not be considered restrictive in any way. The scope of the invention is given by the appended claims, rather than the preceding description, and all variations and equivalents which fall within the range of the claims are intended to be embraced therein. | A system comprises a wireless master unit and one or more wireless slave units, each having a unique identifier. When a wireless slave unit is active, it is addressed by one of a limited number of temporary addresses. A PARK mode enables a wireless slave unit to be in an idle state during which its temporary address is deallocated, enabling that address to be assigned to another wireless slave unit. To page a parked slave, a paging beacon packet is broadcast to, and received by, each of the wireless slave units at fixed intervals during a master-to-slave time slot. Each wireless slave unit determines whether the received paging beacon packet includes its unique identifier. If so, the wireless slave units retrieves a temporary address from the paging beacon packet. The wireless unit transmits a response to the wireless master unit during a subsequent slave-to-master time slot if the received paging beacon packet included the unique identifier belonging to the wireless slave unit. Parked wireless slave units are also assigned a unique response number by the master. The master broadcasts a polling beacon packet during a master-to-slave time slot. If the parked slave unit desires access to the channel, it transmits a response in an N:th slave-to-master time slot following the polling beacon packet, where N is a function of the slave's unique response number. | 8 |
REFERENCE TO RELATED APPLICATION
This application is a divisional application of U.S. patent application Ser. No. 08/999,196, filed on Dec. 29, 1997 and issued as U.S. Pat. No. 6,047,407 on Apr. 11, 2000.
FIELD OF THE INVENTION
The present invention relates to novelty hats and items of clothing in general, and particularly to novelty hats having one or more candles, lamps or light holders depicted thereon. The hats may also be provided with flame tips or light bulbs which may be releasably attachable above the candles, lamps or light holders. Such hats may be worn by children during the joyous celebration of religious holidays, such as the Jewish holiday of Chanukah or the Christian holiday of Christmas.
BACKGROUND OF THE INVENTION
While there are many novelty hats and items of clothing of different varieties known in the art, there are no novelty hats or items of clothing particularly designed and configured for depicting the lighting of candles or lamps thereon. Additionally, there are no such hats or items of clothing having a Menorah depicted thereon for use during the celebration of the eight-day holiday of Chanukah. Nor are there any such hats having a Christmas tree, an Easter candle or an Advent wreath depicted thereon for use during Christmas, Easter and Advent, respectively.
While it is also well known that certain hats, such as yarmulkes worn by Jewish males, are worn in the practice of certain religions, the novelty hats of the present invention are in no way meant to be a replacement for or a mockery of any such religious hats. Rather, the hats of the present invention are hats which children may wear during times of religious celebrations or rituals which involve the lighting of candles in order to allow children's participation without the danger of fire. For example, such hats may be worn by children during their play time during the Chanukah celebration, such as when spinning their dreidels.
Among the novelty hats known in the prior art is the hat disclosed in U.S. Pat. No. 4,991,235 wherein the hat has the shape of an automobile, a motorcycle or a boat. The hat is provided with an adjustable interior headband having VELCRO™ fasteners, i.e. detachably engaging plastic hook members and eye members, to allow the hat to fit on heads having various sizes and to permit the hat to be worn at various angles.
U.S. Pat. No. 4,321,708 discloses a golf cap with blinders pivoted to the sides of the visor. The blinder flaps are permanently attached to the cap along a portion of their length, and have one end releasably attached to the visor of the cap by VELCRO™ pads, so as to permit the blinders to be inconspicuously secured when not in use.
U.S. Pat. No. 4,781,451 disclosed a pair of eye glasses or a visor having several patches of VELCRO™ which are aligned to overlay several opposing patches of VELCRO™ provided on the exterior of a headband or hat so as to allow the eye glasses or visor to be releasably attached to the headband or hat.
SUMMARY OF THE INVENTION
The present invention is directed to a hat or item of clothing which has the shape of one or more candles, lamps and/or light holders either depicted on its exterior or provided for permanent or releasable attachment to the hat or item of clothing. One or more flame tips or light bulbs, which are preferably releasably attachable to the hat adjacent to the top of the one or more candles, are provided for attachment to the hat to depict the lighting of the one or more candles, lamps and/or lights as a symbolic gesture during a time of celebration or other occasion. The hat may be of any shape, and may either fully or partially cover the wearer's head or may be a headband. The one or more candles and corresponding flame tips may be of any size or shape. While, for the sake of simplicity the embodiments of the invention will be referred to herein as hats, it is understood that the invention includes any item of clothing, such as a shirt or vest.
In one embodiment, the hat may have nine candles depicted on its front and the candles may be configured in the general shape of a Menorah wherein the center candle extends upwardly above the other eight candles. This embodiment may be worn by children during the Jewish religious celebration of Chanukah. The tallest candle and one other candle have flame tips or light bulbs attached to their top ends on the first day of Chanukah, and on each of the next seven days of Chanukah a flame tip or light bulb is attached adjacent the top of one of the remaining seven candles.
In another embodiment, the hat may have one large Easter candle depicted on its front. A flame tip or light bulb may be attached adjacent the top of the candle during the celebration of the Christian religious holiday of Easter and whenever appropriate.
In another embodiment, the hat may have four candles depicted on its front in the general configuration of an Advent wreath. During each of the four weeks of Advent, a candle may symbolically be lit by attaching a flame tip or light bulb to the top of the candle.
While it is preferable for the candles to be permanently attached to the hat and the flame tips to be releasably attachable, both the candles and the flame tips may be releasably attachable. Additionally, both the candles and the flame tips may be permanently attachable to the hat.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a planar view of a Chanukah hat embodiment of the invention wherein nine candles in the general configuration of a Menorah are depicted on the front of the hat.
FIG. 2 is a planar view of an Advent hat embodiment of the present invention wherein the hat is in the form of a headband and is provided with four attachable candles and flame tips in the general shape of an Advent Wreath.
FIG. 3 is a planar view of a Christmas tree embodiment of the present invention wherein the hat is provided with one or more battery powered light sockets for insertion of a light bulb therein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In one preferred embodiment, the novelty hat of the present invention is formed in the generally pyramid shape of the hat 10 of FIG. 1 . On the front face thereof, hat 10 has depicted nine candles 12 which are in the general shape of a Menorah. Candles 12 may be releasably attachable to hat 10 , however, they are preferably permanently attached thereto. If candles 12 are releasably attached, it is preferable to utilize interlocking plastic hooks and loops, such as VELCRO™ fasteners.
Nine flames 14 are provided for attachment adjacent the tops of candles 12 . Preferably, VELCRO™ means for attachment are provided on the front face of hat 10 and on the rear face of flame tips 14 for releasable attachment thereto.
During the joyous celebration of the Jewish feast of Chanukah, on day one, the center flame 14 and one adjacent flame 14 may be releasably attached to hat 10 above respective candles 12 . On each successive day during the celebration of Chanukah, a flame 14 may be releasably attached to the front face of hat 10 adjacent the top of a candle 12 . As such, in using the hat made in accordance with the invention, young children may actively participate in the symbolic lighting of the Menorah during the eight days of Chanukah without the danger of exposing the children to the risk of open flames.
With reference to FIG. 2, another preferred embodiment of the invention is a generally cylindrical hat in the form of a headband 16 having depicted on the face thereof the general configuration of an evergreen Advent Wreath 18 having four candles 20 . Preferably, and in the tradition of an Advent Wreath and the Christian religion, three of the candles are purple and one is pink. The candles 20 are preferably situated around the wreath in an evenly spaced manner.
Flame tips 22 are provided for releasable attachment to the front face of hat 16 . Preferably, VELCRO™ attachment means are provided for releasably attaching flame tips 22 matching portions of VELCRO™ attachment means may be provided on the front face of hat 16 adjacent the top of candles 20 and on the rear faces of flame tips 22 . During the Christian religious practice of lighting an Advent Wreath candle for each of the four weeks of Advent, children may wear this embodiment of a novelty heat made in accordance with the invention, thereby taking part by symbolically lighting the candles on the hat without any danger associated with open flames.
While the foregoing embodiments illustrate the preferred attachment means of VELCRO™ fasteners, any means of attachment for either permanent or releasable attachment may be used. For example, matching metallic pieces wherein one or both pieces is magnetized; matching male and female snap pieces wherein one piece has one or more protrusions and one piece has one or more matching cavities; adhesive of any type; and/or pins, such as safety pins or hat pins, may be utilized to affix the candles and/or flame tips to the hat.
Additionally, while the foregoing preferred embodiments illustrate a Chanukah hat having a Menorah depicted thereon and an Advent hat having an Advent Wreath depicted thereon, the present invention includes any hat having any number of candles in any configuration depicted thereon or permanently or releasably attachable thereto.
For example, one embodiment of a hat made according to the present invention may have a single large Easter candle depicted thereon. A flame tip is provided for releasably attaching to the hat adjacent the top of the Easter candle. Matching means for releasable attachment are provided on the front face of the hat adjacent the top of the candle and on the rear face of the flame tip.
In another preferred embodiment of the invention as shown in FIG. 3, the hat 24 may be generally in the shape of an evergreen Christmas tree, such as a balsam fir tree. Hat 24 is provided with a battery housing 26 for holding a battery 28 , and electrical wiring connecting said battery 28 to light socket 30 located adjacent the top of tree 24 and/or light sockets at other locations. Light bulb 32 is provided for removable insertion into light socket 30 by either a press-fit or by screwing an approximately shaped light bulb base into an appropriately groove-shaped light bulb socket, as is well known.
Christmas tree hat 24 may also be provided with candles 34 on one or more of the faces of the hat. Flame tips 36 and means for releasably attaching flame tips 36 adjacent the tops of candle 34 . The hat 24 may have an interior layer of foam and an exterior layer of felt fabric. The candles and flame tips may be made of felt fabric, and the attachment means may be VELCRO™ fasteners.
Numerous other embodiments of novelty hats made in accordance with the invention may also be constructed.
Essentially any material may be used for the hat, candles and flame tips. For example, and without limitation, any type of plastic, fabric, felt, foam, compressible foam, cardboard or paper, or any combination thereof, may be used to construct a hat in accordance wit the present invention. In a preferred embodiment, felt fabric is used for the hat, candles and flame tips, and an inner layer of compressible foam may be used in constructing the hat.
Additionally, any colors may be used for the hat, candles and flame tips. In a preferred embodiment of a hat made in accordance with the invention, having a Menorah depicted thereon, the hat is royal blue, the candles are white and the flame tips are yellow. For the embodiment of the invention having an Advent Wreath depicted thereon, the hat may be red or white, the evergreen wreath green three candles may be purple and one candle pink, and the flame tips may be yellow. | The present invention relates to novelty hats and items of clothing in general, and particularly to novelty hats having one or more candles, lamps or light holders depicted thereon. The hats may also be provided with flame tips or light bulbs which may be releasably attachable above the candles, lamps or light holders. Such hats may be worn by children during the joyous celebration of religious holidays, such as the Jewish holiday of Chanukah or the Christian holiday of Christmas. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to apparatus for tunneling holes through the ground, as for example air-operated impact devices for tunneling substantially horizontally for the purpose of laying cables or pipes beneath roadbeds or other surface structures.
Air-operated impact devices are commonly used for horizontal tunneling beneath roadbeds or other surface structures and are constructed similar to the device described in my earlier U.S. Pat. No. 4,144,941, issued on Mar. 20, 1979. In the typical operating environment for this type of device, an excavation must be dug to a sufficient depth at the point where the hole tunneling operation is to begin. A second excavation is dug at the desired exit point of the tunneling device, again to a depth sufficient to permit the device to cleanly exit from the ground. After these excavations have been prepared, the tunneling device is carefully placed at the proper depth in the first excavation and is carefully aligned in both a horizontal and vertical plane toward the second excavation. The device is then activated to enter the ground and begin tunneling toward the second excavation. After a period of time, which is dependent upon the depth of tunneling, soil material and condition, length of tunnel and other factors, the device will travel underground in a direction generally aligned with its initial position until it exits from the ground at the second excavation.
Boring devices such as drills, wherein the soil is removed from the ground during drilling, operate differently than impact devices, which form a tunnel by compacting the soil around the device. The hammers of impact devices typically reciprocate at rates approaching sixty times per second, so that each impulse causes a small forwardly directed motion. The tip of the impact device is usually conically shaped, from a narrow front and expanding to a rear dimension which approximates the desired diameter of the hole. As the tip moves forward, the surrounding layer of soil is compacted around the tunnel.
One of the significant problems encountered with the use of impact devices is the length of time necessary to complete the tunnel. This occurs primarily where the soil is highly compacted or dense. In this situation the increased resistance to expansion of the hole delays the forward movement of the device through the soil. The amount and nature of resistance encountered by the impact device also directly affects the operator's ability to direct the impact device in a generally straight line. By decreasing the resistance of the soil to the impact device tip, the impact device will move faster and in a generally straight line toward the second excavation.
SUMMARY OF THE INVENTION
An object of the invention is to provide an impact device for tunneling beneath surface structures wherein the resistance of the soil to the impact device is decreased.
Another object of the invention is to provide a forward tip for an impact device wherein the soil surrounding the impact device will be lubricated and more easily compacted.
The present invention consists of an impact device operating generally in the manner described in my prior patent, U.S. Pat. No. 4,144,941, issued on Mar. 20, 1979. Additionally, my present invention is capable of wetting the soil surrounding the forward end of the impact device, thereby reducing the impact resistance of the soil. The cylinder portion of the impact device consists of an elongate outer housing and a threaded front extension upon which a conically-shaped front tip is attached. A plurality of raised buttons are spaced about the forward end of the housing to assist in the tunneling operation of the invention. The forward end of the front tip has a headpiece mounted thereon which has a discontinuous shoulder and neck section for providing an annular spaoe about the front tip for injecting water. The headpiece has fluid outlets opening into this annular space, through which water or other liquids may be released to lubricate the front tip.
The outer housing of the cylinder encloses a reciprocating piston which has a hammer section at its front end. In operation, the hammer contacts an anvil located on the interior front end of the cylinder to propel the impact device forwardly through the soil. The headpiece is shaped to protect the fluid outlets from being plugged by dirt and provides a weighted end for increasing the force of each impact with the soil.
An advantage of the present invention is that the cylinder tip may be adapted for use on a wide variety of impact devices.
BRIEF DESCRIPTION OF THE DRAWINGS
A preferred embodiment of the invention is disclosed hereinafter, with reference to the appended drawings, in which:
FIG. 1 illustrates the apparatus in plan view and partial cross section;
FIG. 2 illustrates an enlarged view of the front of the invention cross-section;
FIG. 3 illustrates the view taken along lines 3--3 of FIG. 1; and
FIG 4 is a cross section taken along lines 4--4 of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
One form of the impact device is illustrated by the drawings and is described herein as 10. The impact device 10 consists of an elongate cylinder 11 having a closed, conically shaped front tip 12 and enlarged headpiece 13 threaded on the front end of the cylinder 11. A plurality of raised, hemispherical buttons 12a are spaced about the exterior surface of front tip 12, to assist in the operation of the invention. A plurality of rearwardly directed fluid outlets 14 are positioned immediately behind the headpiece 13 on the front end of the front tip 12. The outer surface of the cylinder 11 includes fluid conduits 15 which communicate with internal passages 16 located in the front tip 12. Passages 16 communicate with a central passage 35 which opens into an interior chamber 40 in front tip 12 to release fluid through the fluid outlets 14.
The interior of the cylinder 11 includes an anvil 17 and a reciprocable piston 18. The piston 18 is slidably mounted within cylinder 11 and is hollow along part of its interior axial length, but has a solid front piece which comprises a hammer 19. Near the rear end of piston 18 are a plurality of ports 20 which open through flat surfaces 21 formed along the outside surface of piston 18. The rear end of the cylinder is threaded to accept an end cap 22 The end cap 22 has longitudinal ports 23 for permitting the exhausting of compressed air from within cylinder 11 in a manner hereinafter described.
A spool 24 is positioned in slidable relation with the interior surface of the piston 18. The spool 24 has a bore 25 drilled along its axial length which comprises a passage for compressed air into the interior of the impact device 10 and piston 18 via coupler 26 and air hose 27. The rear end of the spool 24 is threadable through the end cap 22 and includes a narrowed diameter 28 immediately forward of the end cap 22. The hose coupler 26 is designed for attachment to a suitable high pressure air hose 27 and when secure attachment is made, it is possible to twist the attached air hose 27 and cause the spool 24 to be threadably engaged or disengaged relative to cylinder 11, thereby causing the front end of spool 24 to move axially within cylinder 11.
The conical portion at the front end of cylinder 11 includes a threaded bore to which may be attached a threaded rear extension 34 of the front tip 12. The threaded extension 34 includes a central bore 35 which communicates with the fluid passages 16 to enable fluid to flow from the fluid conduits 15 on cylinder 11 to the fluid outlets 14. In the preferred embodiment there are four equally spaced fluid outlets 14.
Fluid conduits 15 are affixed against the outside surface of cylinder 11, and each fluid conduit 15 has a front opening sealably connected into a passage 16, and a rear opening sealably connected into a manifold or fluid coupler 29. The fluid coupler 29 is designed for attachment to a suitable fluid hose 30, to permit fluid, preferably water, to flow through the fluid conduits 15 and fluid passages 16 to the fluid outlets 14 located on the front tip 12 as shown in FIG. 2. The fluid hose 30 is preferably connected to an adjustable fluid pump to provide an adjustable fluid supply for controlling the lubrication of the front tip 12.
As an alternative construction the fluid hose 30 could be carried inside of air hose 27 and be coupled to a rotatable liquid coupler and seal affixed to the rear of cylinder 11 in the proximate position of fluid coupler 29. As a further alternative construction, the fluid conduits 15 could be constructed in the form of elongate passages through the outer wall of cylinder 11 and along the length of cylinder 11.
FIG. 3 illustrates a view taken along lines 3--3 of FIG. 1, wherein the location of the ports 20 is shown. Each port 20 is positioned to open on a flat surface 21 of the piston 18. The ports 20 provide air communication paths between the interior and exterior of the piston 18. The ports 20 may be covered by the spool 24 during at least a portion of the piston 18 travel distance over the spool 24, and may be uncovered during a further travel portion of piston 18. In the view shown in FIG. 2, the piston 18 is in its forwardmost position, where the ports 20 are uncovered from the spool 24. In its rearmost position, the piston 18 slides rearward over the spool 24 and the ports 20 are uncovered by the narrowed diameter 28 of spool 34. At intermediate positions the ports 20 are blocked by the larger diameter of the spool 24.
FIG. 4 shows a cross-sectional view taken along the lines 4--4 of FIG. 2. The fluid outlets 14 open through the exterior surface of front tip 12, and are preferably arranged to face rearwardly toward the conical surface so as to provide a directional fluid flow which permits the surface of front tip 12 to become bathed in fluid. The external openings of fluid outlets 14 are preferably arranged behind an enlarged nose or front piece, so as to create a void to freely permit the flow of fluid onto the external surface of front tip 12 In practice, a plurality of fluid outlets 14 are preferred, arranged more or less uniformly about the front tip 12 so as to provide a uniform flow of fluid. Fluid outlets 14 are all coupled to central bore 35 so as to provide a common fluid flow path to all such outlets.
In operation, compressed air is applied via the air pressure hose 27 attached to the coupler 26. The compressed air passes through the bore 25 to the interior of piston 18 and exerts a forward driving force against the piston 18. This force causes the piston 18 to move sharply ahead, contacting the hammer 19 against the anvil 17. At its forwardmost position, the piston 18 uncovers the ports 20 and the internally pressurized air is vented to the exterior of the piston 18. This vented pressurized air passes through the openings created by flat surfaces 21 on the exterior surface of piston 18, and inside the interior of cylinder 11, and acts upon the rear inner piston surface 31 to sharply drive the piston 18 in a rearward direction. The piston 18 proceeds rearward until the ports 20 again become uncovered by the narrowed diameter 28 of the spool 24. At this point, the compressed air between the piston 18 and the interior surface of cylinder 11 is vented into the rear chamber 32, and then out the longitudinal ports 23 through the end cap 22. When the piston 18 is in its rearward position, compressed air entering via the bore 25 again acts to drive the piston 18 forwardly to repeat the cycle.
Each time the hammer 19 contacts the anvil 17, the headpiece 13 on the front tip 12 is forced forwardly into the soil. As the headpiece 13 moves through the soil, fluid may be released from the fluid outlets 14, thereby lubricating the conical surface 33 and the soil at a point behind the headpiece 13 to decrease the resistance of the soil to the front tip 12 as the hole is enlarged. The fluid outlets 14 are angled rearwardly to promote the lubrication of the conical surface 33 and to reduce the possibility of becoming clogged by dirt. The hemispherical buttons 12a are believed to assist in the forward motion of tool 10, both by providing compression points against the adjacent soil and by providing voids along the external conical surface to ease the flow of lubricating water over the surface.
The spool 24 may be threadably moved along its axis in either direction, thereby varying the stroke range of the apparatus. For example, if spool 24 is positioned in its forward axial position as shown in FIG. 1, the stroke of the piston 18 causes the hammer 19 to sharply contact the anvil 17, and produce a forward driving impulse. Conversely, if the spool 24 is threaded toward the end cap 22, the stroke of the piston 18 may be shifted so as to prevent any contact between the hammer 19 at the anvil 17. If the spool 24 is fully retracted toward the end cap 22, the stroke of the piston 18 may be adjusted so as to cause contact between the rear outer piston surface 36 against the end cap 22, to create a reverse impulse and cause the apparatus to move in a rearward direction.
The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. | An impact tool having an air-operated hammer for impacting against an anvil in the body of the tool to cause the tool to tunnel through the ground and having passages and conduits opening to the front tip of the tool to pass water to lubricate the tool to ease the passage of the tool through the soil during the propulsion of the tool, the front tip further having a headpiece through which the passages open to the tool exterior surface. | 4 |
PRIORITY AND CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of International Application No. PCT/DE2004/000796 filed Jan. 29, 2004, which claims priority to German application 103 05 849.4 filed Feb. 12, 2003, both of which are incorporated herein in their entirety by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates to the field of logic devices, and more particularly, it relates to 3 & 2 to 3 carry-ripple adders.
[0004] 2. Description of the Related Art
[0005] Carry-ripple adders have sequential carry logic, and similar carry-save adders, they have a plurality of inputs of equal significance and, during operation, sum the bits applied to these inputs. The sum is provided at outputs of different significance, for example in binary coded numerical notation (BCD).
[0006] In order to add a plurality of bits of equal significance, for example in multipliers, it is known to build carry save adder arrays, for example in accordance with the Wallace tree algorithm, and to finally use a vector merging adder (VMA) to convert the resultant sum, and carry data representation in redundant numerical notation into unambiguous numerical notation. This final stage is often in the form of a carry-ripple adder, two bits of equal significance respectively being summed. In the case of such an approach, it is thus necessary for the carry save adder tree to generally be reduced to two bits for the purposes of addition.
[0007] Consequently, use has only been made of carry-nipple adders that add two input bits and one carry, one sum bit of significance 2 n and one carry of significance 2 n+1 being generated. This results in the need for multistage approaches such that a carry save adder tree in accordance with the number of input bits is first of all used and finally a 2-bit carry-ripple adder is used.
[0008] Solutions for carry-ripple adders that add up to five input bits of equal significance, for example 2 n , are known. However, these configurations are disadvantageous, both as regards the processing speed and as regards the substrate area required, for an implementation using complementary CMOS gates on account of the resultant high number of transistors.
BRIEF SUMMARY OF THE INVENTION
[0009] By way of introduction only, a carry-ripple adders described, including uses thereof. An exemplary carry-ripple adder enables small layouts, or reduction in the area for the carry-ripple adder, and a reduced power loss during operation. A carry-ripple adder may generate two carries, or carry bits, of equal significance, where the carries, or carry bits, are passed directly to the next stage of a multistage carry-ripple adder and assessed therein.
[0010] An exemplary carry-ripple adder may have three first inputs for supplying three input bits of equal significance 2 n that are to be summed, two second inputs for supplying two carry bits of equal significance 2 n+1 that are also to be summed, one output for outputting a calculated sum bit of significance 2 n , and two outputs for outputting two calculated carry bits of equal significance 2 n+1 which is higher than the significance 2 n of the sum bit. A final carry-ripple stage VMA (vector merging adder) may be used even after a reduction to three bits. This makes it possible to save on one carry save stage, which has an advantageous effect on the processing speed and the substrate area of the overall circuit, or to use the third input bit of each carry-ripple adder for the efficient implementation of accumulators, for example in MAC structures.
[0011] Dynamic implementation of carry paths and their logic implementation within a carry-ripple adder additionally make it possible to optimize the area and speed in comparison with complementary or differential CMOS solutions. Simultaneously generating two carries, or carry bits, of equal significance that are assessed in each stage of the carry-ripple adder means that the circuit complexity and the internal wiring complexity are lower than multistage complementary CMOS solutions which are, for example, composed of 3-bit carry save adders and 2-bit carry-ripple adders. This also applies to dynamic carry-ripple adders having three inputs.
[0012] Because of the considerably reduced number of transistors in a carry path, the carry-ripple adder has been optimized in terms of area and power loss. The carry-ripple adder may be used as a final adder in multipliers, adder trees, filter structures, accumulators and arithmetic logic units.
[0013] An carry-ripple adder may also include a precharge input that drives an integrated precharge logic stage, a carry stage, and a summation stage, and combinations thereof. The carry stage may have two carry addition blocks that independently calculate the carry output signals in a temporally parallel manner. The summation stage may have a quintuple XOR function or block.
[0014] A bit addition device may include a parallel circuit that has multiple carry-ripple adders where 3 input bits of equal significance 2 n being provided for each carry-ripple adder.
[0015] The foregoing summary is provided only by way of introduction. The features and advantages of the carry-ripple adder may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the claims. Nothing in this section should be taken as a limitation on the claims, which define the scope of the invention. Additional features and advantages of the present invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a shows a schematic illustration of a 3 & 2 to 3 carry-ripple adder.
[0017] FIG. 2 shows a truth table for a 3 & 2 to 3 carry-ripple adder.
[0018] FIG. 3 shows a schematic illustration of an internal design of a 3 & 2 to 3 carry-ripple adder.
[0019] FIGS. 4, 4A , and 4 B show a schematic illustration of the connection of a carry-ripple adder for three input words having five bits each.
[0020] FIG. 5 shows a schematic illustration of a carry stage.
[0021] FIG. 6 shows a schematic circuit diagram of a block of the carry stage shown in FIG. 5 .
[0022] FIG. 7 shows a schematic circuit diagram of the second block of the carry stage shown in FIG. 5 .
[0023] FIG. 8 shows a schematic illustration of a sum block.
[0024] FIG. 9 shows a schematic circuit diagram of a quintuple XOR stage of the sum block.
[0025] FIG. 10 shows a schematic block diagram for carry-ripple adders.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Exemplary carry-ripple adders will now be described more fully with reference to the accompanying drawings. In each of the following figures, components, features and integral parts that correspond to one another each have the same reference number. The drawings of the figures are not true to scale.
[0027] FIG. 1 shows a schematic illustration of a 3 & 2 to 3 carry-ripple adder 10 having three bit inputs i 0 , i 1 and i 2 , two equivalent carry inputs ci 1 , ci 2 , two equivalent carry outputs co 1 , co 2 and a sum output s.
[0028] FIG. 2 shows a truth, or function, table for one bit in the carry-ripple adder shown in FIG. 1 . On the basis of the coding selected for the two equivalent carry output signals co 2 and co 1 , input combinations where ci 2 =1 and ci 1 =0 (hashed in FIG. 2 ) do not occur during operation since ci 2 can only be set if ci 1 has also been set, from which a double carry is deduced. This fact that “don't care elements” occur is used to minimize the circuit. The simple sum of the five input bits at the inputs i 0 , i 1 , i 2 , ci 1 , ci 2 results at position s in the table, and a carry is generated at the output co 1 if the sum of the input bits is, for example,≧2, a 1 being applied to the output co 2 as soon as the sum of the five input bits is ≧4 but co 1 then already having been set to 1 since the sum is also ≧2.
[0029] FIG. 3 shows a block diagram of an exemplary basic design of a carry-ripple adder 10 having three input bits i 0 , i 1 , i 2 , two equivalent carry inputs ci 1 , ci 2 , two equivalent carry outputs co 1 , co 2 and a sum output s. The adder 10 includes two blocks 11 , 12 : a carry stage 11 , and a summation stage or circuit 12 . The signals prech_ 1 and prechq_ 1 which are optionally supplied preferably control an integrated precharge logic stage if a dynamic implementation is provided. The three input bits i 0 , i 1 , i 2 and the two carry input bits ci 1 and ci 2 are respectively supplied to the two blocks 11 and 12 , as are a supply voltage vdd and a reference ground potential vss. The carry outputs co 1 and co 2 are operated using the carry block 11 . In the a dynamic implementation, the precharge signals prech_ 1 and prechq_ 1 are applied to complementary inputs of the carry block 11 . The summation block 12 has the sum output s, and the precharge signal prechq_ 1 is applied to an inverting input of said summation block in the case of a dynamic implementation.
[0030] FIGS. 4, 4A , and 4 B schematically show the connection of a carry-ripple adder for three input words i 0 , i 1 and i 2 each having 5 bits <4:0>, 5 carry-ripple adders as shown in FIG. 2 being coupled to one another, one carry-ripple adder 10 for each bit position <n> (n=0 to 4). The nth stage adds to the three input bits i 0 <n>, i 1 <n> and i 2 <n> having the significance 2 n two carry input signals ci 1 <n> and ci 2 <n> which likewise have the significance 2 n and generates a sum signal s_n of equal significance 2 n and two carry output signals co 1 <n+1>, co 2 <n+1> of the next higher significance 2 n+1 which correspond to the carry input signals ci 1 <n+ 1 >, ci 2 <n+ 1 > of the n+1th stage, n being an integer between 0 and 4, inclusive, in the present example shown in FIG. 4 .
[0031] FIG. 5 schematically shows a carry stage 11 of a carry-ripple adder as shown in FIG. 3 and/or FIG. 4 . The carry stage 11 has two blocks 13 and 14 which each calculate a carry output signal co 2 and co 1 independently of one another and thus in a temporally parallel manner. Both the block 13 for calculating the carry output signal co 2 and the block 14 for calculating the carry output signal co 1 are connected to the inputs i 0 , i 1 , i 2 , ci 1 and ci 2 of the supply voltage vdd and the reference ground potential vss. In the case of a dynamic implementation, the two blocks 13 and 14 are preferably connected to the precharge signals prech and prechq that are supplied in such a manner that they are inverted, or having opposite poloarity, with respect to one another.
[0032] FIG. 6 shows a schematic circuit diagram of a dynamic implementation of the block 13 (shown in FIG. 5 ) for generating the carry output signal co 2 on the basis of the signals at the three bit inputs i 0 , i 1 , i 2 , the two carry inputs ci 1 and ci 2 and the precharge signals prech and prechq. A p-channel field effect transistor P is driven, on the gate side, by the precharge signal prechq. The p-channel field effect transistor P is also connected between the supply voltage vdd and a node 17 . An n-channel FET N is connected, on the gate side, to the carry input ci 1 . The n-channel FET N is also connected between the node 17 and a node 18 . The node 18 may be connected to the supply voltage vdd via an n-channel FET N that is driven, on the gate side, with the precharge signal prech. A series circuit comprising three n-channel FETs N is located between the node 18 and the reference ground potential vss, one of said n-channel FETs being connected, on the gate side, to i 0 , the next n-channel FET being connected, on the gate side, to i 1 , and the third n-channel FET being connected, on the gate side, to i 2 .
[0033] An n-channel FET is connected, on the gate side, to the carry input ci 2 , and is connected between the node 17 and a node 19 . A series circuit comprising two n-channel FETs N is located between the node 19 and the reference ground potential vss, one of said n-channel FETs in the series circuit of two n-channel FETs between node 19 and the reference ground is connected, on the gate side, to i 1 and the other is connected to i 2 . A parallel circuit of two n-channel FETs N is parallel to said series circuit between the node 19 and a node 20 . One of the n-channel FETs of the parallel cirucit of two n-channel FETs N between node 19 and 20 is connected, on the gate side, to i 1 , the second is connected, on the gate side, to i 2 . The drains of each of the n-channel FETs of the parallel cirucit are combined or connected to node 20 which is connected to the reference ground potential vss via an n-channel FET N to which i 0 is applied on the gate side. The node 19 is optionally connected to the supply voltage vdd via an n-channel FET having a gate connected to the precharge signal prech.
[0034] A series circuit of a p-channel FET P and an n-channel FET N is arranged in a further parallel branch between the supply voltage vdd and the reference ground potential vss, where the p-channel FET P is connected, on the gate side, to node 17 and the precharge signal prech is applied to the n-channel FET N on the gate side. The carry output co 2 is provided at a junction between the p-channel field effect transistor P and the n-channel FET N of the series circuit between the supply voltage vdd and the reference ground potential vss.
[0035] FIG. 7 illustrates a schematic circuit for dynamically implementing the block 14 shown in FIG. 5 . A p-channel FET P having a gate to which the precharge signal prechq is applied, is connected between a supply voltage vdd and a circuit node 21 . A series circuit of two n-channel FETs N is provided between the node 21 and a reference ground potential vss. The carry input ci 1 is applied to the gate of one of the n-channel FETs and i 2 is applied to the gate of the second n-channel FET of the series circuit of two n-channel FETs N provided between the node 21 and the reference ground potential. A parallel circuit of two n-channel FETs N is parallel to the series circuit between the node 21 and a node 22 , where one of the n-channel FETs is connected, on the gate side, to i 2 and the other n-channel FETs is connected, on the gate side, to the carry input ci 1 . The node 22 is connected in turn, via a parallel circuit of two n-channel FETs N, to the reference ground potential vss in a manner dependent on i 0 or i 1 . One of the n-channel FETs of the parallel circuit between node 22 and the reference ground Vss is connected, on the gate side, to i 0 and the other n-channel FETs is connected, on the gate side, to i 1 .
[0036] The circuit node 22 may be connected, via an n-channel FET N, to the supply voltage vdd in a manner dependent on the precharge signal prech, where the precharge signal prech is connected to the gate of the n-channel FET N connected between the supply voltage and node 22 .
[0037] Provided as further parallel branches between the circuit node 21 and the reference ground potential vss is a series circuit of two n-channel FETs N, where i 1 is applied to one of the n-channel FETs on the gate side, and i 0 is applied to the other n-channel FET on the gate side. In addition, an n-channel FET N to which ci 2 is applied on the gate side, is connected parallel to the series circuit between the circuit node 21 and the reference ground potential vss. A series circuit of a p-channel FET P and an n-channel FET N is connected, as a parallel branch, between the supply voltage vdd and the reference ground potential vss. The p-channel FET P of the series circuit connected between the supply voltage vdd and the reference ground potential vss is connected, on the gate side, to the node 21 . The n-channel FET N of the series circuit connected between the supply voltage vdd and the reference ground potential vss is connected, on the gate side, to receive the precharge signal prech. The carry output signal co 1 is provided at the junction of the p-channel FET P and n-channel FET N of the series circuit connected between the supply voltage vdd and the reference ground potential vss.
[0038] FIG. 8 shows a schematic illustration of the sum block 12 shown in FIG. 3 and/or FIG. 4 and shows (on the left hand part) a possible implementation of the input stage. A series circuit comprising a p-channel FET P and an n-channel FET N is arranged between a supply voltage vdd and a reference ground potential vss, where the precharge signal prechq is applied to the p-channel field effect transistor P on the gate side, and the signal at the carry input ci 1 is applied to the n-channel FET N on the gate side. The circuit node 23 at which the signal i 1 q is tapped off is located between the p-channel FET P and the n-channel FET N. The signal i 1 q at the node 23 is converted into a signal i 1 using an inverter 1 which is connected to both the reference ground potential vss and the supply voltage vdd. A similar input stage is provided for each input signal ci 1 , ci 2 , x 1 (which corresponds to i 0 ), x 2 (which corresponds to i 1 ) and x 3 (which corresponds to i 2 ) (see FIG. 4 ). The signals i 2 q and i 2 are generated, for the sum block, from the carry input ci 2 . The signals i 3 and i 3 q are generated from the input signal x 1 . The signals i 4 and i 4 q are generated from the input signal x 2 . The signals i 5 and i 5 q are generated from the input signal x 3 .
[0039] FIG. 8 shows (on the right hand part) a schematic illustration of the sum block, with resorting likewise being carried out again in this case since i 3 shown in FIG. 8 (left-hand part) becomes x 1 , i 3 q becomes x 1 q , i 4 becomes x 2 , i 4 q becomes x 2 q , i 5 becomes x 3 , i 5 q becomes x 3 q , i 2 becomes x 4 , i 2 q becomes x 4 q , i 1 becomes x 5 and i 1 q becomes x 5 q . In addition, the summation device shown in FIG. 8 (right hand part) has a precharge access having the signal prechq, an enable input EN (the signal prechq also being applied to the enable input EN), a sum output s and a connection to the reference ground potential vss and the supply voltage vdd. The input stage shown in FIG. 8 (left hand part) is used to synchronize the sum stage with dynamic circuit parts of the overall circuit.
[0040] FIG. 9 shows a schematic circuit diagram, of an exemplary quintuple XOR function stage, or circuit, as the sum block shown in FIG. 8 . The two time critical carry signals ci 1 , which are converted into i 1 and i 1 q , and thus into x 5 and x 5 q (see FIG. 8 ), and the carry input signal ci 2 , which is converted into i 2 and i 2 q , and thus into x 4 and x 4 q , are preferably connected to n-channel field effect transistors N located next to the outputs Z and ZQ of the XOR circuit. The quintuple XOR stage 15 shown in FIG. 9 is connected to the supply voltage vdd by means of an upstream connection 24 in a manner dependent on the precharge signal prechq and, in addition, can be connected to the reference ground potential vss via an enable signal EN at the gate of an n-channel field effect transistor N. This enable signal EN is supplied via the enable input shown in FIG. 8 (right hand part).
[0041] FIG. 10 illustrates carry-ripple adders B 1 , B 2 , B 3 where the output carry bits are of unequal significance.
[0042] Although the present invention has been described above with reference to a preferred exemplary embodiment, it is not restricted thereto but rather can be modified multifariously. The circuit principle of the carry path, which is based on calculating and forwarding two carries of equal significance, can therefore also be used for two carry signals which are interchangeable. In addition, the blocks which are used to generate the two carry signals are not necessarily independent of one another. In the case of an implementation using complementary CMOS gates, it is possible to make joint use of subblocks. However, separation is advantageous for a high-performance application.
[0043] In addition, the n-channel transistors N which are located in the evaluation part of the carry gates (see FIG. 6 and FIG. 7 ) and to whose gate the precharge signal prech is applied are not required for a basic implementation of the logic function. They reduce the charge sharing problem that can arise depending on the technology and layout. They are therefore optional, may also be in the form of p-channel FETs with inverted driving, and constitute advantageous optimization. Any static or dynamic quintuple XOR gate may, in principle, be used as the sum stage. In addition, other carry-ripple adder may be utilized without any restriction.
[0044] The above described embodiments are given as illustrative examples only. It will be readily appreciated that many deviations may be made from the embodiments disclosed in this specification without departing from the invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.
LIST OF REFERENCE SYMBOLS
[0000]
i 0 , i 1 , i 2 Inputs for input bits
x 1 , x 2 , x 3 Inputs for input bits
i 0 < 0 > i 0 < 4 >,
i 1 < 0 > i 1 < 4 >,
i 2 < 0 > i 2 < 4 > Input bits at corresponding inputs
ci 1 , ci 2 Inputs for carry bits
s, s 0 s 4 Summation outputs
cot, cot Outputs for carry bits
2n Significance of a bit (n=natural number)
2n+1 Significance of a bit that has been increased by one
prech, prechq Precharge inputs
prech 1 , prechq 1 Precharge inputs
vdd Supply voltage
vss Reference ground potential
10 Carry-ripple adder/bit summation device
11 Carry stage (carry summation)
12 Summation stage (normal summation or carry)
13 Carry addition block
14 Carry addition block
15 Quintuple XOR stage
16 Multibit carry-ripple adder
17 , 18 , 19 , 20 Circuit nodes
21 , 22 , 23 Circuit nodes
24 Upstream connection of the quintuple XOR stage
B 1 , B 2 , B 2 Carry-ripple adders based on the prior art in which the output carry bits are of unequal significance
P, N p-channel FET, n-channel FET
en Enable signal | A carry-ripple adder having inputs for supplying three input bits of equal significance 2 n that are to be summed and two carry bits of equal significance 2 n+1 that are also to be summed. A calculated sum bit of significance 2 n and two calculated carry bits of equal significance 2 n+1 which are higher than the significance 2 n of the sum bit are provided at outputs. A final carry-ripple stage VMA may be used even after a reduction to three bits. | 6 |
REFERENCE TO PENDING PRIOR PATENT APPLICATION
[0001] This patent application claims benefit of pending prior U.S. Provisional Patent Application Ser. No. 61/638,956, filed Apr. 26, 2012 by Brian James Katerberg et al. for MODULAR TRAY (Attorney's Docket No. HAYES-15 PROV), which patent application is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to orthopedic prostheses in general, and more particularly to prosthetic tibial components for knee joint prostheses.
BACKGROUND OF THE INVENTION
[0003] Joint replacement surgery seeks to replace some or all of a natural joint with prosthetic components so as to provide long-lasting function and pain-free mobility.
[0004] For example, in the case of a prosthetic total hip joint, the head of the femur is replaced with a prosthetic femoral stem component, and the socket of the acetabulum is replaced by a prosthetic acetabular cup component, whereby to provide a prosthetic total hip joint.
[0005] In the case of a prosthetic total knee joint, the top of the tibia is replaced by a prosthetic tibial component, and the bottom of the femur is replaced by a prosthetic femoral component, whereby to provide a prosthetic total knee joint.
[0006] The present invention is directed to orthopedic prostheses for restoring the knee joint and, in particular, to improved prosthetic tibial components.
[0007] Looking now at FIG. 1 , there is shown a prior art prosthetic total knee joint 5 which generally comprises a prosthetic tibial component 10 secured to the top end of a resected tibia 15 , and a prosthetic femoral component 20 which is secured to the bottom end of a resected femur 25 .
[0008] A typical prior art prosthetic tibial component 10 is shown in greater detail in FIGS. 2 and 3 . Prior art prosthetic tibial component 10 generally comprises a metal base construct 30 and a polyethylene bearing construct 35 .
[0009] More particularly, metal base construct 30 generally comprises a baseplate 40 having a top surface 42 and a bottom surface 43 , a stem 45 and a plurality of posts 50 descending from bottom surface 43 of baseplate 40 and into resected tibia 15 , and a plurality of screws 55 passing through baseplate 40 and into resected tibia 15 . Baseplate 40 preferably has a peripheral profile which generally matches the peripheral profile of the resected tibia 15 . Metal base construct 30 also comprises a pair of locking rails 60 fixed to the top surface 42 of baseplate 40 and defining a groove 65 therebetween, and a pair of end walls 70 connected to top surface 42 of baseplate 40 . Preferably bottom surface 43 of baseplate 40 (and, optionally, stem 45 and/or posts 50 ) comprises a porous material so as to allow bone ingrowth into baseplate 40 (and/or stem 45 and/or posts 50 ), whereby to facilitate osseo-integration of baseplate 40 (and/or stem 45 and/or posts 50 ) with resected tibia 15 over time. Additionally and/or alternatively, baseplate 40 and/or stem 45 and/or posts 50 may be fixed to resected tibia 15 with bone cement.
[0010] Polyethylene bearing construct 35 comprises a sculpted upper surface 71 having a central ridge 72 which separates a pair of scalloped seats 73 for receiving the condyles (either natural or prosthetic) of the lower femur. Polyethylene bearing construct 35 also comprises a flat bottom surface 75 having a recess 80 in which is disposed a tongue 85 . Tongue 85 is sized to slidingly fit in the groove 65 which is defined by locking rails 60 of metal base construct 30 ( FIG. 3 ), whereby polyethylene bearing construct 35 may be slidingly secured to locking rails 60 of metal base construct 30 . Note that end walls 70 of locking metal base construct 30 act as stops for polyethylene bearing construct 35 when tongue 85 of polyethylene bearing construct 35 is advanced into the groove 65 which is defined by locking rails 60 of metal base construct 30 .
[0011] In use, the top end of tibia 15 is resected, and metal base construct 30 is secured to tibia 15 , i.e., by advancing stem 45 and posts 50 into resected tibia 15 until bottom surface 43 of baseplate 40 is seated against resected tibia 15 . Note that the parallel dispositions of stem 45 and posts 50 facilitates advancement of stem 45 and posts 50 into the resected tibia. Next, screws 55 are advanced through baseplate 40 and into resected tibia 15 , whereby to secure metal base construct 30 to resected tibia 15 . Then polyethylene bearing construct 35 is locked onto metal base construct 30 , e.g., by sliding tongue 85 of polyethylene bearing construct 35 into the groove 65 which is defined by locking rails 60 of metal base construct 30 until polyethylene bearing construct 35 engages end walls 70 of baseplate 40 . Thereafter, the knee joint is reduced, allowing the condyles (either natural or prosthetic) of the lower femur to settle into the scalloped seats 73 of polyethylene bearing construct 35 .
[0012] Unfortunately, in some patients, the natural geometry of the knee is such that there may be some degree of misalignment between the condyles (either natural or prosthetic) of the lower femur and the scalloped seats 73 of polyethylene bearing construct 35 of the prosthetic tibial component 10 . Specifically, the anterior-posterior centerline of the condyles (either natural or prosthetic) of the lower femur, and the anterior-posterior centerline of the scalloped seats 73 of polyethylene bearing construct 35 of the prosthetic tibial component 10 , may be angularly offset from one another. As a result, the condyles (either natural or prosthetic) of the lower femur may not seat properly in the scalloped seats 73 of polyethylene bearing construct 35 of the prosthetic tibial component 10 . This may occur at some or all of the extent of flexure of the knee. This mis-seating of the condyles (either natural or prosthetic) of the lower femur in the scalloped seats 73 of polyethylene bearing construct 35 of the prosthetic tibial component 10 can lead to reduced stability of the knee in both static and dynamic conditions, and can lead to excessive wear of the polyethylene bearing construct 35 over time. In addition, this mis-seating of the condyles (either natural or prosthetic) of the lower femur in the scalloped seats 73 of polyethylene bearing construct 35 of the prosthetic tibial component 10 can lead to early loosening of the prosthetic tibial component, or to early loosening of the prosthetic femoral component, or both, and/or it can result in poor bone coverage leading to bone subsidence.
[0013] Thus there is a need for a new and improved prosthetic tibial component for a knee joint prosthesis which can provide for better alignment between the condyles (either natural or prosthetic) of the lower femur and the scalloped seats of the polyethylene bearing construct of the prosthetic tibial component.
SUMMARY OF THE INVENTION
[0014] The present invention comprises the provision and use of a new and improved prosthetic tibial component for a knee joint prosthesis which provides for better alignment between the condyles (either natural or prosthetic) of the lower femur and the scalloped seats of the polyethylene bearing construct of the prosthetic tibial component.
[0015] More particularly, the present invention comprises the provision and use of a new and improved prosthetic tibial component for a knee joint prosthesis which provides for better alignment of the anterior-posterior centerline of the condyles (either natural or prosthetic) of the lower femur and the anterior-posterior centerline of the scalloped seats of the polyethylene bearing construct of the prosthetic tibial component.
[0016] In one preferred form of the invention, there is provided a prosthetic tibial component for a knee joint, said prosthetic tibial component comprising:
[0017] a base construct for engaging the tibia; and
[0018] a bearing construct for engaging the femoral side of the knee joint;
[0019] said bearing construct being adjustably fixedly mountable to said base construct.
[0020] In another preferred form of the invention, there is provided a method for reconstructing a knee joint, said method comprising:
[0021] providing a prosthetic tibial component for a knee joint, said prosthetic tibial component comprising a base construct for engaging the tibia, and a bearing construct for engaging the femoral side of the knee joint, said bearing construct comprising a pair of concave seats for receiving the condyles of the femoral side of the knee joint, and said bearing construct being adjustably fixedly mountable to said base construct;
[0022] resecting the tibia; and
[0023] mounting said base construct to said resected tibia and adjustably fixedly mounting said bearing construct to said base construct so that said pair of concave seats in said bearing construct are appropriately aligned with the condyles of the femoral side of the knee joint.
[0024] In another preferred form of the invention, there is provided a prosthetic tibial component for a knee joint, said prosthetic tibial component comprising:
[0025] a base construct comprising a baseplate for attachment to the tibia and a mount for receiving a bearing construct for engaging the femoral side of the knee joint, said mount being adjustably fixedly mountable to said baseplate.
[0026] In another preferred form of the invention, there is provided a prosthetic component for a joint, said prosthetic component comprising:
a base construct for engaging a first bone of the joint; and a bearing construct for engaging a second bone of the joint;
[0029] said bearing construct being adjustably fixedly mountable to said base construct.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] These and other objects and features of the present invention will be more fully disclosed or rendered obvious by the following detailed description of the preferred embodiments of the invention, which is to be considered together with the accompanying drawings wherein like numbers refer to like parts, and further wherein:
[0031] FIG. 1 is a schematic side view showing a prior art prosthetic total knee joint;
[0032] FIG. 2 is a schematic partially-exploded perspective view showing a prior art prosthetic tibial component;
[0033] FIG. 3 is a schematic front view showing a prior art prosthetic tibial component secured to a resected tibia;
[0034] FIG. 4 is a schematic view showing a reconstructed knee joint, wherein the tibial side of the reconstructed knee joint comprises a novel prosthetic tibial component which is secured to the top end of a resected tibia, and the femoral side of the reconstructed knee joint comprises a prosthetic femoral component which is secured to the bottom end of a resected femur;
[0035] FIG. 5 is a schematic view showing the tibial side of the reconstructed knee joint shown in FIG. 4 ;
[0036] FIGS. 6 and 7 are schematic views showing the femoral side of the reconstructed knee joint shown in FIG. 4 ;
[0037] FIGS. 8 and 9 are schematic views showing the novel prosthetic tibial component shown in FIG. 4 ;
[0038] FIG. 10 is a schematic exploded view showing the modular metal base construct of the novel prosthetic tibial component shown in FIGS. 8 and 9 ;
[0039] FIG. 11 is a schematic view showing the polyethylene bearing construct of the novel prosthetic tibial component shown in FIGS. 8 and 9 ;
[0040] FIGS. 12A , 12 B and 12 C show the locking rail element of the modular metal base construct of FIG. 10 in a range of angular positions (i.e., FIG. 12A shows the locking rail element externally rotated, FIG. 12B shows the locking rail element in a “neutral” position, and FIG. 12C shows the locking rail element internally rotated);
[0041] FIGS. 13A , 13 B and 13 C are views similar to those of FIGS. 12A , 12 B and 12 C, respectively, but with the polyethylene bearing construct shown mounted to the modular metal base construct (i.e., FIG. 13A shows the polyethylene bearing construct externally rotated, FIG. 13B shows the polyethylene bearing construct in a “neutral” position, and FIG. 13C shows the polyethylene bearing construct internally rotated); and
[0042] FIG. 14 is a schematic view showing one preferred construction for securing the locking rail element to the remainder of the modular metal base construct.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The Novel Prosthetic Tibial Component
[0043] The present invention comprises the provision and use of a new and improved prosthetic tibial component for a knee joint prosthesis which provides for better alignment between the condyles (either natural or prosthetic) of the lower femur and the scalloped seats of the polyethylene bearing construct of the prosthetic tibial component.
[0044] More particularly, the present invention comprises the provision and use of a new and improved prosthetic tibial component for a knee joint prosthesis which provides for better alignment of the anterior-posterior centerline of the condyles (either natural or prosthetic) of the lower femur and the anterior-posterior centerline of the scalloped seats of the polyethylene bearing construct of the prosthetic tibial component.
[0045] Looking now at FIG. 4 , there is shown a novel prosthetic total knee joint 105 which generally comprises a novel prosthetic tibial component 110 secured to the top end of a resected tibia 115 , and a prosthetic femoral component 120 which is secured to the bottom end of a resected femur 125 .
[0046] As will hereinafter be discussed in further detail, and looking now at FIG. 5 , novel prosthetic tibial component 110 generally comprises a modular metal base construct 130 and a polyethylene bearing construct 135 . As will also hereinafter be discussed in further detail, novel prosthetic tibial component 110 is characterized by two scalloped seats 173 which define an anterior-posterior centerline 136 of the polyethylene bearing construct 135 .
[0047] Prosthetic femoral component 120 is shown in greater detail in FIGS. 6 and 7 , and is characterized by two condyles 137 which define an anterior-posterior centerline 138 .
[0048] As will hereinafter be discussed, novel prosthetic tibial component 110 is configured so as to allow the anterior-posterior centerline 136 of the scalloped seats of polyethylene bearing construct 135 to be better aligned with the anterior-posterior centerline 138 of the two condyles 137 of the lower femur, whereby to provide for better alignment between the condyles of the lower femur and the scalloped seats of the polyethylene bearing construct.
[0049] More particularly, and looking now at FIGS. 8-10 , modular metal base construct 130 generally comprises a baseplate 140 and a locking rail component 141 .
[0050] Baseplate 140 has a top surface 142 for receiving polyethylene bearing construct 135 , an opposing bottom surface 143 for engaging resected tibia 115 , a stem 145 descending from the bottom surface of baseplate 140 for extending into resected tibia 115 , a bore 146 extending through baseplate 140 and into stem 145 , and a plurality of screw holes 156 extending through baseplate 140 for receiving screws (not shown) for securing baseplate 140 to resected tibia 115 . Baseplate 140 preferably has a peripheral profile which generally matches the peripheral profile of the resected tibia 115 .
[0051] Locking rail component 141 comprises a body 157 having a pair of locking rails 160 running along its top surface 161 and defining a groove 165 therebetween. Groove 165 extends along a longitudinal axis 166 . Body 157 of locking rail component 141 also has an end wall 170 connected to top surface 161 of body 157 and connecting locking rails 160 to one another. A post 169 descends from body 157 of locking rail component 141 and is sized to be received in bore 146 of baseplate 140 and secured therein. Preferably the bottom surface 143 of baseplate 140 (and, optionally, stem 145 ) comprises a porous material so as to allow bone ingrowth into baseplate 140 (and/or stem 145 ), whereby to facilitate osseo-integration of the baseplate 140 (and/or stem 145 ) with resected tibia 115 over time. Additionally and/or alternatively, baseplate 140 and/or stem 145 may be fixed to resected tibia 115 with bone cement.
[0052] Looking now at FIGS. 8 , 9 and 11 , polyethylene bearing construct 135 comprises a sculpted upper surface 171 having a central ridge 172 which separates a pair of scalloped seats 173 for receiving the condyles (either natural or prosthetic) of the lower femur. Polyethylene bearing construct 135 also comprises a flat bottom surface 175 having a recess 180 in which is disposed a tongue 185 which extends along a longitudinal axis 186 . Note that longitudinal axis 186 of tongue 185 extends parallel to the anterior-posterior centerline 136 of scalloped seats 173 of the polyethylene bearing construct 135 . Tongue 185 is sized to slidingly fit in groove 165 of locking rails 160 of locking rail component 141 ( FIG. 11 ), whereby polyethylene bearing construct 135 may be slidingly secured to locking rail component 141 of modular metal base construct 130 . Note that end wall 170 of locking rail component 141 acts as a stop for polyethylene bearing construct 135 when tongue 185 of polyethylene bearing construct 135 is advanced into groove 165 of locking rail component 141 of modular metal base construct 130 . Note also that when polyethylene bearing construct 135 is mounted to locking rail component 141 , the anterior-posterior centerline 136 of the scalloped seats 173 of the polyethylene bearing construct 135 , and the longitudinal axis 186 of the tongue 185 of polyethylene bearing construct 135 , both extend parallel to longitudinal axis 166 of groove 165 of locking rail component 141 .
Use of the Novel Prosthetic Tibial Component
[0053] In use, the top end of tibia 115 is first resected.
[0054] Next, baseplate 140 is secured to tibia 115 , i.e., by advancing stem 145 into resected tibia 115 until the bottom surface 143 of baseplate 140 is seated against resected tibia 115 , and by advancing screws through holes 156 of baseplate 140 and into resected tibia 115 , whereby to secure baseplate 140 to resected tibia 115 .
[0055] Then locking rail component 141 is mounted to baseplate 140 by advancing post 169 of locking rail component 141 into bore 146 of baseplate 140 and fixedly locking post 169 in bore 146 , whereby to fixedly secure locking rail component 141 vis-à-vis baseplate 140 . Note that prior to fixedly securing locking rail component 141 to baseplate 140 , the angular disposition of locking rail component 141 is carefully adjusted vis-à-vis baseplate 140 (and hence vis-à-vis resected tibia 115 ), such that the longitudinal axis 166 of groove 165 of locking rail component 141 is aligned with the anterior-posterior centerline 138 of the two condyles 137 of the lower femur (which will thereafter assure, when polyethylene bearing construct 135 is mounted to locking rail component 141 , that the anterior-posterior centerline 136 of the scalloped seats 173 of polyethylene bearing construct 135 are appropriately aligned with the anterior-posterior centerline 138 of the two condyles 137 of the lower femur). By way of example but not limitation, as seen in FIGS. 12A , 12 B and 12 C, the longitudinal axis 166 of groove 165 of locking rail component 141 is oriented to an appropriate angular position relative to baseplate 140 so that the longitudinal axis 166 of groove 165 is appropriately aligned with the anterior-posterior centerline 138 of the two condyles 137 of the lower femur.
[0056] Next, polyethylene bearing construct 135 is locked onto modular metal base construct 130 , e.g., by sliding tongue 185 of polyethylene bearing construct 135 into groove 165 of locking rail component 141 of modular metal base construct 130 until polyethylene bearing construct 135 engages end wall 170 of locking rail component 141 . This action will cause the anterior-posterior centerline 136 of the scalloped seats 173 of polyethylene bearing construct 135 to be aligned with the longitudinal axis of groove 165 of locking rail component 141 (see FIGS. 13A , 13 B and 13 C), and hence appropriately aligned with the anterior-posterior centerline 138 of the two condyles 137 of the lower femur. Note that polyethylene bearing construct 135 may be offered in a range of sizes so as to minimize any “overhang” vis-à-vis baseplate 140 when polyethylene bearing construct 135 is set in an externally rotated position ( FIG. 13A ) or in an internally rotated position ( FIG. 13C ).
[0057] Thereafter, the joint is reduced, allowing the condyles (either natural or prosthetic) of the lower femur to settle into the scalloped seats 173 of polyethylene bearing construct 135 of prosthetic tibial component 110 .
[0058] If, after the joint is reduced, it is found that the kinematics of the joint are not satisfactory, the joint can be distracted again, polyethylene bearing construct 135 can be removed, locking rail component 141 can be repositioned vis-à-vis baseplate 140 , polyethylene bearing construct 135 can be remounted to locking rail component 141 , and then the joint can be reduced again. In this way, optimal positioning of the anterior-posterior centerline 136 of the scalloped seats 173 of polyethylene bearing construct 135 can be achieved vis-à-vis the anterior-posterior centerline 138 of the two condyles 137 of the lower femur.
[0059] Furthermore, if revision surgery should subsequently be required to adjust the positioning of the anterior-posterior centerline 136 of the scalloped seats 173 of polyethylene bearing construct 135 , this can be achieved in a similar manner.
Mounting the Locking Rail Component to the Baseplate
[0060] As discussed above, post 169 of locking rail component 141 is advanced into bore 146 of baseplate 140 and fixedly locked in position, whereby to fixedly secure locking rail component 141 to baseplate 140 . It will be appreciated that various arrangements may be provided to effect this securement. By way of example but not limitation, and looking now at FIG. 14 , post 169 may receive an expanding collet 187 so as to cause post 169 to radially expand and thereby “grip” the side wall of bore 146 of baseplate 140 . More particularly, in this construction, a screw 188 may pass through a hole 189 formed in body 157 of locking rail component 141 so as to pull collet 187 proximally, whereby to radially expand post 169 within bore 146 and fixedly secure post 169 in bore 146 .
[0061] Alternatively, and by way of further example, post 169 may comprise a Morse taper for binding with the side wall of bore 146 of baseplate 140 .
[0062] Or, by way of still further example, post 169 may be formed with a compressible design for forming a friction grip with the side wall of bore 146 .
[0063] And post 169 and recess 146 of baseplate 140 may be formed with threads for fixedly securing post 169 in recess 146 .
[0064] In still another form of the invention, a male-female connection is used to fixedly secure locking rail component 141 to baseplate 140 , but in this alternative form of the invention, the male portion of the connection is formed on baseplate 140 and the female portion of the connection is formed on locking rail component 141 .
[0065] Still other approaches for securing locking rail component 141 to baseplate 140 will be apparent to those skilled in the art in view of the present disclosure.
Further Aspects of the Invention
[0066] In addition to the foregoing, it should also be appreciated that polyethylene bearing construct 135 may be mounted to locking rail component 141 before the locking rail component 141 is mounted to baseplate 140 , and/or locking rail component 141 may be mounted to baseplate 140 before baseplate 140 is mounted to resected tibia 115 .
[0067] Also, while in the foregoing description the novel prosthetic tibial component is discussed in the context of use with a prosthetic femoral component, it should be appreciated that the novel prosthetic tibial component may be used in conjunction with the natural condyles of a femur.
[0068] And it should be appreciated that the present invention is not restricted to “dual-compartment” knee joint reconstructions, i.e., it may also be applied to “uni-compartment” knee joint reconstructions where only one scalloped seat 173 and one femoral condyle is involved.
[0069] In addition to the foregoing, it should be appreciated that it is common in the orthopedic field to test a joint reconstruction using “trial” components prior to committing to the joint reconstruction using the actual prosthetic components. In this respect it should be appreciated that the present invention may be applied to trial components as well as to the actual prosthetic components.
Application to Other Joints
[0070] It should be appreciated that the present invention may be utilized in prostheses for joints other than the knee. By way of example but not limitation, the present invention may be utilized in an elbow joint prosthesis, an ankle joint prosthesis, a spinal prosthesis, etc.
Modifications
[0071] It should also be understood that many additional changes in the details, materials, steps and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the present invention, may be made by those skilled in the art while still remaining within the principles and scope of the invention. | A prosthetic tibial component for a knee joint, said prosthetic tibial component comprising:
a base construct for engaging the tibia; and a bearing construct for engaging the femoral side of the knee joint; said bearing construct being adjustably fixedly mountable to said base construct. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
1. Field of the Invention
The present invention relates to devices for handling coiled tubing for oil drilling operations. More particularly, the present invention relates to reels that have a capacity to hold extended lengths of coiled tubing. Still more particularly, the present invention relates to sectional transportable reels that have a capacity to hold extended lengths of coiled tubing.
2. Description of the Related Art
Coiled tubing, as currently deployed in the oilfield industry, generally includes small diameter cylindrical tubing made of metal or composites that have a relatively thin cross sectional thickness. Coiled tubing is typically much more flexible and much lighter than conventional drill string. These characteristics of coiled tubing have led to its use in various well operations. Coiled tubing is introduced into the oil or gas well bore through wellhead control equipment to perform various tasks during the exploration, drilling, production, and workover of a well. For example, coiled tubing is routinely utilized to inject gas or other fluids into the well bore, inflate or activate bridges and packers, transport well logging tools downhole, perform remedial cementing and clean-out operations in the bore, and to deliver drilling tools downhole. The flexible, lightweight nature of coiled tubing makes it particularly useful in deviated well bores.
Typically, coiled tubing is introduced into the oil or gas well bore through wellhead control equipment. A conventional handling system for coiled tubing can include a reel assembly, a gooseneck, and a tubing injector head. The reel assembly includes a rotating reel for storing coiled tubing, a cradle for supporting the reel, a drive motor, and a rotary coupling. During operation, the tubing injector head draws coiled tubing stored on the reel and injects the coiled tubing into a wellhead. The drive motor rotates the reel to pay out the coiled tubing and the gooseneck directs the coil tubing into the injector head. Often, fluids are pumped through the coiled tubing during operations. The rotary coupling provides an interface between the reel assembly and to a fluid line from a pump. Such arrangements and equipment for coiled tubing are well known in the art.
While prior art coiled tubing handling systems are satisfactory for coiled tubing made of metals such as steel, these systems do not accommodate the relatively long lengths of drill or working strings achievable with coiled tubing made of composites. Such extended lengths of composite coiled tubing strings are possible because composite coiled tubing is significantly lighter than steel coiled tubing. In fact, composite coiled tubing can be manufactured to have neutral buoyancy in drilling mud. With composite coiled tubing effectively floating in the drilling mud, downhole tools, such as tractors, need only overcome frictional forces in order to tow the composite coiled tubing through a well bore. This characteristic of composites markedly increases the operational reach of composite coiled tubing. Thus, composite coiled tubing can allow well completions to depths of 20,000 feet or more, depths previously not easily achieved by other methods.
Moreover, composites are highly resistant to fatigue failure caused by “bending events,” a mode of failure that is often a concern with steel coiled tubing. At least three bending events may occur before newly manufactured coiled tubing enters a well bore: unbending when the coiled tubing is first unspooled from the reel, bending when travelling over a gooseneck, and unbending upon entry into an injector. Such accumulation of bending events can seriously undermine the integrity of steel coiled tubing and pose a threat to personnel and rig operations. Accordingly, steel coiled tubing is usually retired from service after only a few trips into a well bore. However, composite coiled tubing is largely unaffected by such bending events and can remain in service for a much longer period of time.
Hence, systems utilizing composite coiled tubing can be safely and cost-effectively used to drill and explore deeper and longer oil wells than previously possible with conventional drilling systems. Moreover, completed but unproductive wells may be reworked to improve hydrocarbon recovery. Thus, composite coiled tubing systems can allow drilling operations into territories that have been inaccessible in the past and thereby further maximize recovery of fossil fuels.
However, these dramatic improvements in drilling operations require handling systems that can efficiently and cost-effectively deploy extended lengths of composite coiled tubing. In prior art coiled tubing handling systems, the reel assembly is generally the largest single component of the coiled tubing unit. The size of the reel assembly is often indirectly limited by various governmental codes and regulations. For example, on many domestic highway routes, additional fees are levied on tractor-trailer combinations that exceed a specified weight or size limitation. Further, because offshore platform space is at a premium, many drilling companies place strict requirements on the amount and size of equipment permitted on the rig at any given time. The size and load carrying limits of available barges or transport ships may also limit the physical size of the reel.
Nonetheless, a reel having a large storage capacity provides operational efficiencies. For example, two reels storing 12,000 feet of coiled tubing each can be deployed more efficiently than three reels storing 8,000 feet each. One reason for this efficiency is that a two reel configuration eliminates a reel change-out. That is, by carrying longer lengths at one time, large coiled tubing reels benefit drilling companies because they reduce the number of work stoppages required to insert a new reel of tubing into the work string. Because rig time is very expensive, it is often cost-effective to minimize the elapsed time for tubing deployment.
For these reasons, a coiled tubing system that both maximizes the length of tubing that can be deployed and minimizes the physical size of the unit is desired. Because composite coiled tubing can be deployed in lengths vastly greater than has been possible with steel coiled tubing, there is a need for a transportable reel that can store large quantities of coiled tubing.
In summary, while oil and gas recovery operations could greatly benefit from coil handling systems capable of handling long lengths of coiled tubing, the prior art does not disclose such handling systems.
SUMMARY OF THE PRESENT INVENTION
The present invention overcomes the deficiencies of the prior art by including the design of a reel assembly that can be disassembled for transportation. Such a reel assembly may be deployed more efficiently than prior art designs. One benefit of this design is that the empty reel assemblies can be removed from the coiled tubing platform without disturbing the operation of the remaining reel assemblies in order to provide room on the platform for the remaining reel assemblies to operate without obstruction. This design allows empty reels to be packaged and shipped in a manner that is more efficient than what was possible under the limitations of the prior art.
Other objects and advantages of the present invention will be apparent in the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein:
FIG. 1 illustrates an embodiment of the present invention mounted on a drilling rig;
FIG. 2 is an exploded view of one embodiment of a coiled tubing spool constructed in accordance with the present invention;
FIG. 3 is an end view of an embodiment of the present invention, showing one-half of one side wall removed;
FIG. 3 a is an isometric view of the embodiment of FIG. 3;
FIG. 3 b is an isometric view of the embodiment of FIG. 3 with reinforced wire mesh sidewalls; and
FIG. 4 is and end view of another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a reel 20 constructed in accordance with the present invention is mounted on a cradle 24 located on a drilling rig 26 at a well site. Reel 20 stores an extended length of composite coiled tubing 28 that is run into a well bore 30 . Tubulars made of composites are discussed in pending application Ser. No. 09/081,961 filed May 20, 1998, titled “Well System,” which is hereby incorporated by reference for all purposes. Preferred embodiments of reel 20 that may be adapted to various well sites are described below.
Referring now to FIG. 2, a preferred embodiment of reel 20 includes a drum 40 , a first sidewall 42 , a second sidewall 44 , threaded studs 46 , and nuts 48 . Threaded studs 46 are preferably circumferentially arrayed on end faces 50 , 52 of drum 40 .
First and second sidewalls 42 , 44 retain the composite coiled tubing that may be spooled onto hub 42 . Because first and second sidewalls 42 , 44 are substantially identical, only first sidewall 42 will be described in detail herein. Referring now to FIGS. 3 and 3 a , first sidewall 42 preferably comprises a plurality of sectional flanges 60 contiguously disposed on first drum face 50 . According to a preferred embodiment, flanges 60 include clearance holes 62 arranged to receive threaded studs 46 . A similar arrangement is provided for flanges 61 of second sidewall 44 . It will be understood that any number of releasable locking arrangements may be used to secure flanges 60 to drum 40 . For example, clamps (not shown) adapted to releasably receive flanges 60 may be provided on drum 40 .
It is known that composite coiled tubing spooled onto drum 40 does not impose significant loading along the axis of drum 40 . Accordingly, flanges 60 may be designed with an emphasis on minimizing shipping and handling difficulties. For example, flanges 60 may be formed as thin lightweight steel plates or as walls of reinforced wire mesh to reduce weight. Additionally, flanges may include perforations or be arranged in a non-contiguous fashion for further reductions in size and weight. Indeed, nearly any structure retains the coiled tubing on drum 40 , such as radially disposed bars (not shown), may also be used.
Drum 40 supports the composite coiled tubing spooled onto and payed out from reel 20 . Cradle 24 (FIG. 1) rotates drum 40 via an interconnecting axle 25 . Still referring to FIGS. 3 and 3 a , drum 40 includes a hub 41 , a centerpiece 43 , and a plurality of spokes 45 . Hub 41 is concentrically supported on centerpiece 43 by outwardly radiating spokes 45 . Hub 41 presents a winding surface 49 on which composite coil tubing seats. Arrangements for the winding surface are disclosed in commonly-owned U.S. application Ser. No. 09/443,407 entitled Reel for Supporting Composite Coiled Tubing, which is hereby incorporated by reference for all purposes. Lifting eyes (not shown) may be provided to facilitate shipment and manipulation of drum 40 .
Preferably, the diameter of hub 41 is selected to introduce a strain of 2% or less in the composite coiled tubing. Thus, for composite coiled tubing having a diameter of 2⅞ inches, the diameter of hub 41 should be approximately 144 inches or greater. Similarly, for composite coiled tubing having a diameter of 3{fraction (7/8 )} inches, the hub diameter should be approximately 194 inches or greater. It is expected that a hub diameter selected in accordance with the stated criteria will optimize the operating life of the composite coiled tubing. However, it should be understood that advances in composite materials may allow hub diameters that introduce strains of greater than 2% into the composite coiled tubing.
The several elements of drum 40 are preferably fabricated separately and can be assembled by standard welding procedures, threaded fasteners or any other suitable means. Preferably, drum 40 is formed to be shipped as a single unit. However, if the fabricated diameter of hub 40 is not within permissible transportation limitations, an axle split line 56 be used to break drum 40 into mating semicylindrical halves 58 a,b . Mating semicylindrial halves 58 a,b can be joined using a variety of known methods, such as threaded fasteners (not shown). The use of additional splitlines will further reduce the size and weight of the individual sections that make up drum 40 . Furthermore, the joining method may take advantage of the operational characteristics of composite coiled tubing. For example, when pressurized drilling fluid is pumped into a well via composite coiled tubing, the portion of composite coiled tubing spooled on a reel tends to expand radially. This radial expansion results in a compressive force on hub 40 that may assist in maintaining the structural integrity of drum 40 that incorporates splitlines.
Referring now to FIG. 4, another embodiment of reel 20 includes mating first and second portions 70 , 72 . Because first and second reel portions 70 , 72 are substantially symmetrical, only first reel portion 70 will be described. First reel portion 70 is preferably formed as a single unit having a centerpiece 74 having outwardly radiating spokes 76 that support a hub 78 . Hub 78 provides a winding surface 80 for seating the composite coiled tubing. Sidewalls 82 , 84 are fixed on hub end faces 79 . It will be appreciated that the unitary design of first reel portion 70 allows the use of numerous fabrication methods such as fillet welds, threaded fasteners, interlocking members, or combinations thereof To join first reel portion 70 to second reel portion 72 , a plurality of threaded studs 86 may be provided on spokes 76 of first portion 70 . Clearance holes 88 on second reel portion 72 are adapted to receive threaded studs 86 . Nuts (not shown) threaded onto threaded studs 86 secure first reel portion 70 to second reel portion 72 . It should be understood that first and second reel portions 70 , 72 may be assembled by any suitable number of method and the described use of threaded studs is merely exemplary. Furthermore, it will be understood that reel 20 may be divided into more that two segments. Thus, acceptable arrangements of preferred reel 20 may include three or more portions that are readily releasable and engagable.
For 1500 meters of composite coiled tubing having 2⅞ inch gage, an exemplary reel may have a hub diameter of twelve feet and an overall diameter of eighteen feet. An exemplary disassembly arrangement may include first and second sidewalls that comprise eight flanges each. Such a disassembly arrangement would provide flanges with a maximum width of approximately seven feet and a drum diameter of twelve feet. Thus, the maximum dimension of any component to be transported is reduced from eighteen feet to twelve feet. The sidewall may be formed from more or fewer flanges. Additionally, a split line may be used to further reduce the size and weight of the drum. For composite coiled tubing having gages of 3½ inches, 4½ inches or greater, coiled tubing lengths of 1500 meters would necessitate larger reels. However, such reels would nonetheless breakdown into readily transportable components if designed in accordance with the present invention.
The above described embodiments of the present invention may be used for a well completion or workover operation where the well operator intends to use an extended length of composite coiled tubing. While the composite coiled tubing may be shipped on several separate spools and interconnected during injection into a well bore, a well operator may opt to utilize a single reel for subsequent composite coiled tubing handling.
Typically, a well operator selecting a reel in accordance with the present invention will employ a two-step process to arrive at an optimal design for a reel. The first step is to establish overall design dimensions of the reel with respect to the configuration of coiled tubing to be used. Usually, the overall dimensions of the reel are dictated by the required storege capacity, i.e., the length and gage of composite coiled tubing to be spooled, and the expected static and operational loads. The second step is to establish a disassembly design that facilitates the transportation and handling of the required reel. The disassembly configuration of the reel for a given well site is dictated by factors such as shipping costs, size restrictions along transport routes, the capacity of storage facilities at a well site, applicable safety regulations, and the weight limitations on lifting equipment such as cranes and cables.
Once the design has been established for the several components of the reel (hereinafter the master reel), the master reel components may be fabricated and shipped to the well site. Relatively short lengths of composite coiled tubing are delivered to the well site on small individual reels. During well operations, the short lengths of composite coiled tubing are made-up as required and sequentially injected into a well bore. Arrangements for such an operation are discussed in pending application Ser. No. 09/081,961 titled “Well System.” When operations require that the entire extended length of composite coiled tubing be tripped out of the well bore, the master reel is assembled and installed on a suitable platform. After establishing the appropriate connections, the entire extended length of composite coiled tubing may be spooled onto the master reel. It is contemplated that more than one master reel may be utilized during the spooling/retrieval process. The actual number of master reels, of course, depends on the length of the composite coiled tubing injected into the well. Thus, an extended length of tubing may be readily retrieved and deployed without having to spool the extended length of tubing onto several small reels.
It can be seen that once the present reel is loaded with the extended length of composite coiled tubing at a well site, the reel may be readily transported to other well sites in the vicinity. Moreover, if the reel is housed on a ship, the reel may be transported to nearly any offshore well. Thus, for well servicing operations subsequent to the initial operation, a reel made in accordance with the present invention reduces or even eliminates reel change-outs during both the injection and retrieval phases.
While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Furthermore, where methods have been described, it should be understood that the individual steps of the methods may be executed in any order, unless a specific order is expressly prescribed. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims which follow, the scope of which shall include all equivalents of the subject matter of the claims. | A reel configured to store an extended length of composite coiled tubing has a plurality of sections. In one embodiment, the reel has a drum and pair of detachable sidewalls. Each side wall includes a plurality of flanges. In another embodiment, the reel includes a radial splitline that defines substantially identical securably matable sections. Preferably, the reel can store at least 20,000 feet of composite coiled tubing. | 4 |
The present application is a continuation-in-part of U.S. patent application Ser. No. 08/362,718, filed Dec. 23, 1994, now U.S. Pat. No. 5,607,966.
BACKGROUND OF THE INVENTION
The present invention is directed to the provision of viscoelastic compositions containing compounds having potent anti-inflammatory, anti-oxidant and anti-proliferative activity. The present invention is also directed to various methods of using the compounds and compositions of the present invention in pharmaceutical applications including the treatment of inflammatory disorders such as ocular inflammation associated with ophthalmic disease and ophthalmic surgery.
Inflammation from cellular stress can cause excessive tissue damage. Numerous biochemical pathways are known to lead to inflammation. In general, these include the generation of locally produced or inflammatory cell derived proinflammatory cytokines (e.g., IL 1 , IL 6 , IL 8 and TNF.sub.α), as well as products from the cyclooxygenase system, such as prostaglandins, and the lipoxygenase system, such as leukotrienes, "HETEs" and "HPETEs." Such agents have been associated with inflammation. See generally, Goodman and Gilman's The Pharmacological Basis of Therapeutics, pages 600-617, Pergman Press, N.Y. (1990). Therapies designed to inhibit the production of these types of agents are therefore of great interest.
Non-steroidal anti-inflammatory agents (NSAIA) have been used for the treatment of inflammatory disorders. The following references may be referred to for further background concerning this use of NSAIAs:
Ophthalmoscope, volume 8, page 257 (1910);
Nature volume 231, page 232 (1971);
FASEB Journal, volume 1, page 89 (1987); and
Inflammation and Mechanisms and Actions of Traditional Drugs, Vol. I Anti-inflammatory and Anti-rheumatic drugs. Boca Raton, Fla., CRC Press, (1985).
However, there are some problems associated with NSAIA treatment including delivery to the appropriate site of action and side effects (Goodman and Gilman's The Pharmacological Basis of Therapeutics pages 638-669, Pergman Press, N.Y. (1990)).
Free radical molecules also play a major role in inflammation. These unstable chemical moieties lead to the oxidation of tissue resulting in damage. Such oxidative stress and damage has been described in Biochemical Pharmacology, 32(14), 2283-2286 (1983) and Free Radicals in Biology and Medicine, 4, 225-261 (1988). Agents that act as anti-oxidants can protect against oxidative damage. Such protection has been the subject of numerous scientific publications, including the following:
Archives of Pharmacology, volume 325, pages 129-146 (1992);
Journal of Photochemistry and Photobiology, volume 8, pages 211-224 (1991);
Free Radicals in Biology and Medicine, volume 11, pages 215-232 (1991); and
European Journal of Pharmacology, volume 210, pages 85-90 (1992).
The combination of anti-oxidant activity with other pharmacologically significant activities in a single molecule is discussed in JP 010484 A2 and EP 387771 A2; and compounds with cyclooxygenase/5-Lipoxygenase and anti-oxidant activity are discussed in Drug Research, 39(II) Number 10, pages 1242-1250 (1989). However, these references do not disclose the compounds of the present invention.
Ocular inflammation is a condition which generally causes patient discomfort including red eye, conjunctival edema and congestion, ocular discharge as well as scratchiness and itchiness. Ocular inflammation can be initiated by various insults. For example, ocular inflammation can result from allergic response to various allergens, bacterial infections, trauma to the eye, dry eye and surgical complications. Various anti-inflammatory therapies are currently in use for the treatment of ocular inflammation including the topical administration of diclofenac.
Ocular surgery can result in various post-surgical complications to the eye. Such complications generally include: 1) loss of vascular blood barrier function; 2) neutrophil accumulation; 3) tissue edema including conjunctiva swelling, conjunctiva congestion and corneal haze; 4) cataract formation; 5) cellular proliferation; and 6) loss of membrane integrity including decrease in docosahexaenoic acid levels in membrane phospholipids.
Cataracts are opacities of the ocular lens which generally arise in the elderly. In order to improve eyesight, the cataractous lens is removed and an intraocular lens is inserted into the capsular bag. In order to maximize the procedure and post-surgical recovery, viscoelastic materials are injected in the anterior chamber and capsular bag to prevent collapse of the anterior chamber and to protect tissue from damage resulting from physical manipulation. Various inflammatory responses and tissue damage, however, may still occur from such surgeries, as described above. There is a need, therefore, for the provision of improved viscoelastic compositions and methods which aid in the amelioration of inflammation, tissue damage and trauma-induced complications resulting from anterior segment surgery (e.g., cataract surgery and trabeculectomy).
Trabeculectomy, i.e., glaucoma filtration surgery, involves the surgical creation of a fistula with a conjunctival flap which allows the direct drainage of aqueous humor from the anterior chamber into the conjunctival tissue. This procedure is used as an alternative to drug therapy, and allows for an increase in outflow of aqueous humor, thereby lowering the elevated intraocular pressure associated with glaucoma. In order to maintain a deep chamber and enhance visualization during the surgery, viscoelastic compositions have been injected into the anterior chamber of the eye. Inflammatory responses resulting from the surgery, however, may cause complications. For example, many patients exposed to prior inflammatory episodes (e.g., uveitis, cataract extraction) have an increased incidence of "bleb" failure due to fibroplasia. With such complications, the filtration bleb becomes scarred or heals over so that aqueous drainage can no longer occur. Thus, a need exists for the provision of improved viscoelastic compositions which further decrease the inflammatory response, cellular damage, and proliferation resulting from glaucoma filtration surgery, permitting an increased longevity of the filtration bleb following surgery.
Vitrectomy surgery can also induce a variety of post-surgical complications. Many of these complications are further potentiated in diabetic patients who are at risk for many ocular pathologies. Due to the severity of the surgical procedure, the posterior segment surgery process can cause extensive tissue damage at both the acute and chronic phases of the recovery. Tissue edema generally occurs during the post-surgical acute phase. This is caused by breakdown of the blood aqueous and blood retinal barrier functions resulting in sustained vascular permeability and accumulation of plasma constituents in the ocular compartments following the surgical trauma. Ocular neovascularization may occur during the post-surgical chronic phase. The presence of elevated inflammatory and serum factors induce cell proliferation during the normal wound healing process. Slitlamp clinical examinations at 24 hours have indicated extensive anterior chamber flare and cell influx, conjunctiva congestion and swelling (with discharge), iritis, and corneal haze. See for example, Kreiger, A. E., Wound Complications In Pars Plana Vitrectomy, Retina, volume 13, No. 4, pages 335-344 (1993); Cherfan, G. M., et al., Nuclear Sclerotic Cataract After Vitrectomy for Idiopathic Epiretinal Membranes Causing Macular Pucker, American Journal Of Ophthalmology volume 111, pages 434-438 (1991); Thompson, J. T., et al., Progression of Nuclear Sclerosis and Long-term Visual Results of Vitrectomy With Transforming Growth Factor Beta-2 for Macular Holes, American Journal Of Ophthalmology volume 119, pages 48-54 (1995) and Dobbs, R. E., et al., Evaluation Of Lens Changes In Idiopathic Epiretinal Membrane, volume 5, Nos. 1 & 2, pages 143-148 (1988).
The chronic phase of the postsurgical period is characterized by more severe complications that can necessitate additional surgery. These include an incidence of recurrent retinal detachment, epiretinal proliferation, neovascular glaucoma, corneal problems, vitreous hemorrhage, cystoid macular edema, and occurrence of cataract formation within six months of surgery. While various surgical irrigating and viscoelastic compositions are employed, the frequency of above-described complications still needs to be lessened by facilitating the recovery of vascular leakage and limiting the duration of the cellular proliferative response. Therefore, a need exists to improve the current effectiveness of viscoelastic compositions used in vitrectomy surgery.
U.S. Pat. No. 5,480,914 (Meadows) describes the use of non-aqueous perfluorocarbon carriers to deliver various compounds to the eye. U.S. Pat. No. 5,166,331 (della Velle et al.) discloses the use of hyaluronic acid compositions to deliver various compounds to the eye. Neither of these references, however, disclose the compositions of the present invention. The present invention is directed to the provision of new viscoelastic compositions containing compounds that have potent anti-inflammatory, anti-oxidant and anti-proliferative activity in a single molecule. The use of a single chemical entity with these potent activities provides increased protection relative to the use of a compound with singular activity. The use of a single agent having both activities over a combination of these different agents in a viscoelastic composition provides uniform delivery of an active molecule, thereby simplifying issues of drug metabolism, toxicity and delivery.
SUMMARY OF INVENTION
The present invention provides methods of using novel compounds having potent anti-inflammatory, anti-oxidant and anti-proliferative activity for the treatment of inflammatory conditions, such as: 1) loss of vascular blood barrier function; 2) neutrophil accumulation; 3) tissue edema including conjunctiva swelling, conjunctiva congestion and corneal haze; 4) cataract formation; 5) cellular proliferation; and 6) loss of membrane integrity including decrease in docosahexaenoic acid levels in membrane phospholipids. The multi-therapeutic efficacies of the compounds of the present invention may act in an additive or synergistic manner in reducing cellular damage and inflammation. Additionally, the compounds of the present invention also exhibit other anti-inflammatory activity not present in the individual agents.
The viscoelastic compositions of the present invention contain these novel compounds. The compositions generally are comprised of various viscoelastic vehicles such as sodium hyaluronic acid, chondroitin sulfate, hydroxypropylmethylcellulose ("HPMC"), other naturally occurring or synthetics molecules and combinations thereof.
The compounds of the present invention include both a non-steroidal anti-inflammatory agent (NSAIA) moiety and an anti-oxidant moiety. The compounds of the present invention are therefore useful as cytoprotective agents. The compounds of the present invention also possess anti-proliferative activity. In order to provide effective therapy for inflammatory disorders, especially resulting from ocular surgery, the present invention takes advantage of these individual efficacies. In addition, the present invention improves upon these individual efficacies by providing greater drug delivery to the target tissues by means of administering a single drug having multiple therapeutic actions. The present invention also provides compounds that associate with lipid membranes, thus providing bioavailable anti-oxidant protection within lipid molecules susceptible to oxidation. Finally, the compounds of the present invention exhibit therapeutic properties which are not present in the individual moieties of the compounds. These and other advantages of the present invention will be apparent to those skilled in the art based on the following description.
The NSAIA component of the compounds provides anti-inflammatory activity when it is freed from the parent compound. The use of these NSAIAs will provide inhibition of cyclooxygenase, an important enzyme involved in the prostaglandin/inflammation pathway. Inhibition of the synthesis/release of pro-inflammatory cytokines also reduces the rate of wound healing and the occurrence of fibroplasia. The compounds also include an anti-oxidant component. As oxidative stress has been implicated in inflammatory responses, the presence of an anti-oxidant will further help treat the target tissue.
The compounds of the present invention also exhibit intrinsic properties present only in the combined molecule, not in the individual components. One such property is the inhibitory efficacy against 5-lipoxygenase, an enzyme known to be involved in inflammation.
Another advantage of the present invention is that the anti-inflammatory moiety and the anti-oxidant moiety are linked through an amide or ester bond. Since the carboxylic acid moiety of the NSAIA has been converted to an amide or ester, the resultant molecule is neutrally charged, thus increasing lipophilicity, and drug delivery. These compounds also associate with lipid membranes, thus providing resident antioxidant protection of these oxidizable biomolecules. Furthermore, amide or ester pro-drugs, may provide site-directed anti-inflammatory activity since amidases and esterases, components of the inflammatory response, will catalyze the hydrolysis of the amide or ester and release the non-steroidal anti-inflammatory agent and anti-oxidant.
The compounds of the present invention are capable of protecting against cellular damage by a wide range of insults. Since the compounds provide this protection by decreasing free radical or oxidative damage, reducing enzyme mediated inflammation, cellular proliferation, and improving site delivery, this therapy represents an improved multi-pronged approach to the treatment of inflammatory pathologies.
DETAILED DESCRIPTION OF INVENTION
The compounds of the present invention are of the formula (I):
A--X--(CH.sub.2).sub.n --Y--(CH.sub.2).sub.m --Z (I)
wherein:
A is a non-steroidal anti-inflammatory agent originally having a carboxylic acid;
X is O or NR;
A--X is an ester or amide linkage derived from the carboxylic acid moiety of the non-steroidal anti-inflammatory agent and the X;
R is H, C 1 -C 6 alkyl or C 3 -C 6 cycloalkyl;
Y, if present, is O, NR, C(R) 2 , CH(OH) or S(O) n' ;
n is 2 to 4 and m is 1 to 4 when Y is O, NR, or S(O) n' ;
n is 0 to 4 and m is 0 to 4 when Y is C(R) 2 or is not present;
n is 1 to 4 and m is 0 to 4 when Y is CH(OH);
n' is 0 to 2; and
Z is: ##STR1## wherein: R' is H, C(O)R, C(O)N(R) 2 , PO 3 - , or SO 3 - ; and
R" is H or C 1 -C 6 alkyl.
The compounds of the present invention also include pharmaceutically acceptable salts of the compounds of formula (I).
The compounds of the present invention contain a non-steroidal anti-inflammatory agent, "A", having a carboxylic moiety. A number of chemical classes of non-steroidal anti-inflammatory agents have been identified. The following text, the entire contents of which are hereby incorporated by reference in the present specification, may be referred to for various NSAIA chemical classes: CRC Handbook of Eicosanoids: Prostaglandins, and Related Lipids, Volume II, Drugs Acting Via the Eicosanoids, pages 59-133, CRC Press, Boca Raton, Fla. (1989). The NSAIA may be selected, therefore, from a variety of chemical classes including, but not limited to, fenamic acids, such as flufenamic acid, niflumic acid and mefenamic acid; indoles, such as indomethacin, sulindac and tolmetin; phenylalkanoic acids, such as suprofen, ketorolac, flurbiprofen and ibuprofen; and phenylacetic acids, such as diclofenac. Further examples of NSAIAs are listed below:
______________________________________loxoprofen tolfenamic acid indoprofenpirprofen clidanac fenoprofennaproxen fenclorac meclofenamatebenoxaprofen carprofen isofezolacaceloferac fenbufen etodolic acidfleclozic acid amfenac efenamic acidbromfenac ketoprofen fenclofenacalcofenac orpanoxin zomopiracdiflunisal pranoprofen zaltoprofen______________________________________
The preferred compounds are those wherein "A" is selected from the ester or amide derivatives of naproxen, flurbiprofen or diclofenac. The most preferred compounds are those wherein "A" is selected from the ester or amide derivatives of naproxen or flurbiprofen.
With respect to the other substituents of the compounds of formula (I), the preferred compounds are those wherein:
X is O or NR;
R is H or C 1 -C 3 alkyl;
Y is CH(OH), and m is 0 to 2 and n is 1 or 2, or Y is not present, and m is 1 or 2
and n is 0 to 4;
Z is a, b or d;
R' is H or C(O)CH 3 ; and
R" is CH 3 .
The most preferred compounds are those wherein:
X is O or NR;
R is H;
Y is CH(OH) or is not present;
m is 0 or 1;
n is 1;
Z is a, b, or d;
R' is H; and
R" is CH 3 .
The following compounds are particularly preferred: ##STR2## 2-(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo 1,2-b!pyran-2-yl)methyl 2-(6-methoxy-2-naphthyl)propionate ("Compound B"); ##STR3## N-(2-(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo 1,2-b!pyran-2-yl)methyl) 2-(6-methoxy-2-naphthyl)propionamide ("Compound C"); ##STR4## 2-(6-hydroxy-2,5,7,8-tetramethyl-3,4-dihydro-2H-benzo 1,2-b!pyran-2-yl)ethyl 2-(6-methoxy-2-naphthyl)propionate ("Compound D"); ##STR5## 2-(5-hydroxy-2,4,6,7-tetramethyl-2,3-dihydro-benzo 1,2-b!furan-2-yl)methyl 2-(6-methoxy-2-naphthyl)propionate ("Compound E"); ##STR6## 2-(5-hydroxy-2,4,6,7-tetramethyl-2,3-dihydro-benzo 1,2-b!furan-2-yl)ethyl 2-(6-methoxy-2-naphthyl)propionate ("Compound F"); and ##STR7## 2-(6-hydroxy-2,5,7,8-tetramethyl-2,3-dihydro-2H-benzo 1,2-b!pyran-2-yl)ethyl 2-(3-fluoro-4-phenyl-phenyl)propionate ("Compound G").
The compounds of the present invention may be prepared by methods described in commonly assigned WIPO Publication No. 96/20187, the contents which are directed to synthetic schemes and methods are incorporated herein by reference.
The present invention is particularly directed to the provision of compositions adapted for treatment of inflammatory conditions. The compositions of the present invention will include one or more compounds of formula (I) and a pharmaceutically acceptable viscoelastic vehicle for said compound(s).
Viscoelastic agents which are useful in the compositions of the present invention include but are not limited to: sodium hyaluronate, chondroitin sulfate, polyacrylamide, HPMC, proteoglycans, collagen, methylcellulose, carboxymethyl cellulose, ethylcellulose, polyvinylpyrrolidone and keratan, all of various molecular weights and concentrations, or combinations thereof. Those skilled in the art will appreciate that the suitability of a given agent for a particular step in a surgical procedure will depend upon such things as the agent's concentration, average molecular weight, viscosity, pseudoplasticity, elasticity, rigidity, adherence (coatability), cohesiveness, molecular charge, and osmolality in solution. The agent's suitability will depend further on the function(s) which the agent is expected to perform and the surgical technique being employed by the surgeon. The concentration of the viscoelastic(s) in the compositions of the present invention will depend on various factors, as described below.
An appropriate buffer system (e.g., sodium phosphate, sodium acetate or sodium borate) may be added to prevent pH drift under storage conditions.
Some of the compounds of formula (I) may have limited solubility in water and therefore may require a surfactant or other appropriate co-solvent in the composition. Such co-solvents typically include: polyethoxylated castor oils, Polysorbate 20, 60 and 80; Pluronic® F-68, F-84 and P-103 (BASF Corp., Parsippany N.J., U.S.A.); cyclodextrin; or other agents known to those skilled in the art. Such co-solvents are typically employed at a level of from about 0.01 to 2 wt. %; however, it will be appreciated by those skilled in the art that these molecules may only be employed to the extent that they do not detrimentally affect the viscoelastic properties of the compositions of the present invention.
The viscoelastic compositions containing one or more compound of formula (I) may be used to treat patients afflicted with or prone to various types of cellular damage. In particular, these compositions may be used to treat inflammation where prostaglandins, leukotrienes, inflammatory cytokines and chemokines are known to participate. The concentrations of the compounds in the compositions will depend on various factors, including the nature of the condition to be treated with the compositions. The compounds and compositions of the present invention, however, will be used in a therapeutically effective amount. As used herein, a "therapeutically effective amount" is that amount required to prevent, reduce or ameliorate cellular inflammation, cellular damage and/or proliferation. Generally, the compositions may contain one or more of the compounds of the present invention in a concentration of from about 0.01 μM to about 100 μM.
As indicated above, compounds of formula (I) may be used to treat ocular inflammation at the cellular level and represents a particularly important aspect of the invention. In particular, the compounds are also useful in treating post-surgical complication resulting from ocular surgery. Treatment of the patient pre- or post-surgery with compounds of formula (I) may alleviate such conditions as tissue edema, neovascularization, conjunctiva swelling and congestion, fibroplasia (and scarring), corneal haze and cataract formation.
The methods of the present invention involve the use of various viscoelastic agents having different adherent or cohesive properties. Those skilled in the art will recognize that the compositions of the present invention may be employed by the skilled surgeon in a variety of surgical procedures.
Given the advantages of each type of viscoelastic, the surgeon may employ various viscoelastic compositions of the present invention in a single surgical procedure. U.S. Pat. No. 5,273,056 (McLaughlin et al.) discloses methods which exploit the use of different viscoelastic compositions during a given ocular surgery, the entire contents of which are incorporated herein by reference.
For portions of surgical procedures involving phacoemulsification and/or irrigation/aspiration, e.g., cataract surgery, it is generally preferable to use a viscoelastic agent that possesses relatively greater adherent properties and relatively lesser cohesive properties. Such viscoelastic agents are referred to herein as "adherent" agents. The cohesiveness of a viscoelastic agent in solution is thought to be dependent, at least in part, on the average molecular weight of that agent. At a given concentration, the greater the molecular weight, the greater the cohesiveness. The adherent agents, which are relatively lacking in cohesiveness, therefore will typically be of lower molecular weight; the molecular weight will typically be less than 1,000,000 daltons, preferably less than 750,000 daltons. To achieve a functionally desirable viscosity, the concentrations of the lower molecular weight agents in solution will need to be relatively higher than for higher molecular weight agents. These concentrations will typically be at least about 2% weight to volume (e.g. Occucoat®). The VISCOAT® product, for example, contains approximately 4% chondroitin sulfate (25,000 daltons) and 3% sodium hyaluronate (700,000 daltons). Vitrax® is believed to contain approximately 3% sodium hyaluronate (500,000 daltons). For agents such as these, which are being employed primarily for protective purposes as opposed to tissue manipulation purposes, a functionally desirable viscosity will be a viscosity sufficient to permit a protective layer of such agent to remain on the tissue or cells of concern during the surgical step(s) being performed. Such viscosity will typically be from about 3,000 cps to about 60,000 cps (at shear rate of 2 sec -1 and 25 C), and preferably will be about 40,000 cps. Such adherent agents are capable of providing the protective function previously discussed, yet are not prone to inadvertent removal, which could jeopardize the delicate tissue being protected.
Those portions of surgical procedures involving manipulation of delicate tissue are generally better served by viscoelastic agents that possess relatively greater cohesive properties and relatively lesser adherent properties. Such agents are referred to herein as "cohesive" agents. Typically, these cohesive agents will possess average molecular weights in excess of 1,000,000 daltons and will have functionally desirable viscosity at concentrations of not more than about 1.6% weight to volume. Examples of such cohesive agents are: the Provisc™ product, Healon®, Healon® GV, Amvisc® and Amvisc Plus®. For cohesive agents such as these, which are being employed primarily for tissue manipulation or maintenance purposes as opposed to protective purposes, a functionally desirable viscosity will be a viscosity sufficient to permit the skilled surgeon to use such agent as a soft tool to manipulate or support the tissue of concern during the surgical step(s) being performed. Such viscosity will depend upon the average molecular weight of the agent and its concentration in solution. Most preferred are cohesive agents having an average molecular weight of at least about 2,000,000 daltons and a concentration in solution of between about 1.0 to about 1.4% weight to volume. Such cohesive agents are capable of maintaining intraocular space and manipulating tissue without adhering to it. When their purpose has been served, they can, because of their cohesive properties, be readily removed with minimal trauma to the surrounding tissue.
The present invention may also be used in corneal transplant surgery. In conjunction with the removal of the patient's corneal button, it is desirable to replace the aqueous humor with a highly viscous agent that will provide a firm bed to support the donor cornea, yet be susceptible to easy removal upon completion of the surgery. The donor graft, on the other hand, requires maximum protection from the surgical trauma and should therefore be coated with a different, more adherent agent. Corneal transplant surgery also involves the risks of inflammation and cellular damage. Thus, the compositions of present invention are also useful in this type surgery.
The compositions of the present invention may also be used in posterior segment surgery. In a retinal detachment procedure, for example, a highly viscous, cohesive agent such as the Provisc™ product or Healon® GV will be used to manipulate the retina into position against the basement membrane of the choroid. Small amounts of an adherent agent, such as the VISCOAT® product, may be injected behind the retina before or after such manipulation to temporarily maintain the contact between the retina and basement membrane while more permanent attachment procedures well known to those skilled in the art are performed (e.g. tacking or laser welding).
The methods of the present invention are also directed to using the compositions of the present invention to ameliorate complications arising from glaucoma filtration surgery. Glaucoma filtration surgery involves the surgical creation of a fistula with a conjunctival flap which allows the direct drainage of aqueous humor from the anterior chamber into the conjunctival tissue thereby lowering the elevated intraocular pressure associated with glaucoma. However, in many patients, the filtration "bleb" becomes scarred or healed over so that aqueous drainage can no longer occur. In order to maintain a deep chamber and enhance visualization during the surgery, the viscoelastic compositions of the present invention will be injected into the anterior chamber of the eye. The addition of these compositions will ameliorate inflammatory conditions resulting from the surgery, fibroplasia and decrease bleb failure.
EXAMPLE 1
The following study illustrates the usefulness of compositions of the present invention in glaucoma filtration surgery.
New Zealand albino (NZA) rabbits ranging in body weight from 2.5-3.0 kg were used as experimental animals for the glaucoma filtration surgery model. Following a preoperative ocular examination on the day of the operation, animals were placed under general anesthesia (ketamine HCl (45 mg/kg)/xylazine (6 mg/kg), s.c.). Topical ocular proparacaine HCl (ALCAINE®, Alcon Laboratories, Inc., Fort Worth, Tex.) was administered prior to the start of the surgical procedure to provide ocular analgesia.
A 5 mm superior limbal conjunctival incision was made along the corneal limbus and a conjunctival flap was created. A Weck-Cel microsponge 2×2×2 mm in size (Weck, Research Triangle Park, N.C.) was saturated with 100 μL of either BSS PLUS® (Alcon), mitomycin C (0.5 mg/mL in BSS PLUS®), or test article and placed for 5 minutes between the conjunctiva and sclera to cover the appropriate area of the planned filtration site. The conjunctival wound was then rinsed with about 25 mL of BSS PLUS®. This process was immediately followed by a clear corneal paracentesis, a 2 mm sclerectomy, and an iridectomy. The corneal paracentesis was used to administer 1 mL of a surgical irrigation solution (e.g., BSS PLUS® or COMPOUND D TIS) into the anterior chamber for washing and removal of excess control or test agent administered to the subconjunctival wound. The corneal paracentesis site was also used to administer COMPOUND D, as described above, supplemented PROVISC® (Alcon) composition of the present invention (0.3 mL) to replace the aqueous humor. The conjunctival wound was then closed with 9-0 sutures.
Each study group consisted of 6 animals and received treatment as described in Table 1 below:
TABLE 1______________________________________Summary of Glaucoma Filtration SurgeryExperimental Treatment Groups Conjunctival Wound Treatment Anterior Chamber Anterior ChamberStudy Group (sponge) Irrigation Fluid Replacement______________________________________I BSS PLUS ® BSS PLUS ® BSS PLUS ®II Mitomycin C† BSS PLUS ® BSS PLUS ®III COMPOUND D COMPOUND D COMPOUND D- TIS§ TIS PROVISC ® ‡IV Mitomycin C COMPOUND D COMPOUND D- TIS PROVISC ®______________________________________ †0.5 mg/mL in BSS PLUS §Therapeutic Irrigation Solution consisting of BSS PLUS ® supplemented with COMPOUND D (0.5 μM) and cremophor EL (0.05%) ‡PROVISC ® supplemented with COMPOUND D (0.5 μM) and cremophor EL (0.05%)
Postoperative assessment of bleb vascularity was conducted with conscious animals. Measurement of bleb size was carried out under general anesthesia (ketamine HCl/xylazine). Routine post-surgical examinations were conducted on days 1, 3, 5, 10, and 14 and every week thereafter until the time of bleb failure. Bleb failure was defined as a bleb score value of zero where the bleb score represents the sum of bleb size and height.
The number of functioning blebs through 8 weeks is reported in Table 2, below:
TABLE 2______________________________________ Number of Functioning Blebs Post Operative WeekStudy Group 1 wk 2 wks 4 wks 8 wks______________________________________I 0/6 0/6 -- --II 6/6 6/6 6/6 4/6III 6/6 2/6 1/6 --IV 6/6 6/6 6/6 6/6______________________________________
EXAMPLE 2
The following is an example of a preferred composition of the present invention:
______________________________________Ingredient % w/v______________________________________Compound D 0.000023Cremophor EL 0.05Hyaluronic Acid, Sodium Salt 1Dibasic Sodium Phosphate (Anhydrous) 0.056Monobasic Sodium Phosphate (Monohydrate) 0.004Sodium Chloride 0.84Hydrochloric Acid pH adjustedSodium Hydroxide pH adjustedWater QS______________________________________
EXAMPLE 3
The following is an example of a viscoelastic composition of the present invention wherein "Compound" denotes a compound of the present invention:
______________________________________Ingredient % w/v______________________________________Compound 0.00001-0.0010Cremophor EL 0.05Sodium Chondroitin Sulfate 4.0Sodium Hyaluronate 3.0Sodium Dihydrogen Phosphate, Monohydrate 0.045Disodium Hydrogen Phosphate, Anhydrous 0.2Sodium Chloride 0.310Water QSHydrochloric Acid pH adjustedSodium Hydroxide pH adjusted______________________________________ | Compounds and methods for treating ocular tissues are disclosed. The methods utilize viscoelastic compositions containing certain compounds having an anti-inflammatory and anti-oxidant moiety covalently linked by an amide or ester bond. The compounds are useful in preventing and treating inflammatory and proliferative disorders through several mechanisms. | 0 |
STATEMENT OF GOVERNMENT INTEREST
The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention generally relates to the analysis of fluid flow past an object and more particularly to a method and apparatus for predicting the characteristics of a fluid flowing past such an object.
(2) Description of the Prior Art
Understanding the characteristics of fluid as it flows past an object, such as an airfoil, is important both from the standpoint of understanding and improving the designs of such objects and in understanding the nature of any turbulence introduced as a result of relative motion of a fluid an airfoil, either by moving of the airfoil through the fluid or by moving the fluid past the airfoil.
In the past understandings of fluid flow have been derived from the observation of fluid flow past a model and by specific measurements. For example, U.S. Pat. No. 3,787,874 to Urban discloses a method for making boundary layer flow conditions visible by applying to the surface of a moving or stationary structural body to be exposed to the flow a reactive layer of at least one chemical color indicator, such as a cholesterinic liquid. The body is exposed to a flow of gas, such as air, which contains a reagent. The chemical color indicator can also be applied together with gelling means and a moisture binder. The chemical color indicator can also be absorbed by a high-contrast, absorbent paper which is then applied to the body. A metal or plastic foil coated with a binder and/or indicator can also be used for this purpose. A boundary layer flow pattern image is produced, which can subsequently be recorded.
U.S. Pat. No. 3,890,835 to Dotzer et al. discloses another approach to chemically recording flow patterns by treating the surface to form a reactive layer, entraining in the fluid a reagent compound which is capable of chemically changing the reactive layer, and then passing the fluid over the reactive layer which is to be examined. In this particular disclosure, a blade or other member of aluminum to be examined is treated to form a thin oxide film by anodic treatment. This film is impregnated with an organic dye. As an air stream containing a reactive substance passes over the treated blade, the acid vapors react with the dye and/or the oxide layer and produce a visible pattern upon the blade. This pattern is characteristic of the boundary layer flow of the air stream. An examination of the visible pattern helps to determine the proper design and operating characteristics of the blade.
U.S. Pat. No. 4,380,170 to Dotzer et al. discloses another process for chemically plotting the boundary layer flows over uncompacted, coated, anodically oxidized aluminum surfaces by using a colored or uncolored liquid or a coating or pointillization with a substance, preferably a dye, soluble in water or organic media and which can be included or adsorbed in the eloxal layer.
U.S. Pat. No. 4,727,751 discloses a mechanical sensor for determining cross flow vorticity characteristics. This sensor comprises cross flow sensors which are non-invasively adhered to a swept wing laminar surface either singularly, in multi-element strips, in polar patterns or orthogonal patterns. These cross flow sensors comprise hot-film sensor elements which operate as a constant temperature anemometer circuit to detect heat transfer rate changes. Accordingly, crossflow vorticity characteristics are determined via cross-correlation. In addition, the crossflow sensors have a thickness which does not exceed a minimum value in order to avoid contamination of downstream crossflow sensors.
These prior art approaches present visualizations or measurements that define certain aspects of the characteristics of fluid flow. However, they are designed primarily to determine characteristics at a boundary layer or some other localized site. Each requires the production of a physical model and physical testing of such models. Moreover, if the testing suggests any change to the shape of an airfoil, it is generally necessary to modify the physical model and run the tests again in order to validate any change. Such testing can become time-consuming and expensive to perform.
More recently, it has been proposed to utilize computer modeling techniques to produce such fluid flow analyses. Such computer modeling is attractive because it eliminates the need for physical models and holds the opportunity to reduce testing, particularly if design changes are made to an object undergoing test. Initially such techniques were applied to circular cylinders using a small number of discrete point vortices.
Eventually additional studies determined that vorticity was useful as a basis for understanding fluid flow. Vorticity is produced at a solid boundary because at the surface the fluid has no velocity (i.e., the fluid exhibits a no-slip condition). Once generated at the surface, vorticity diffuses into the volume of the fluid where it is advected by local flow. Conventional vortex methods generally mime this process. In accordance with such methods, the strengths of the vortex elements or segments originating on the body surface are determined by requiring that the velocity induced by all the vortex elements on the surface be equal and opposite to the velocity at the surface. It is assumed that this vorticity is contained in an infinitely thin sheet at the surface. In these methods a resulting matrix equation is solved for the surface vorticity at all points on the body simultaneously. Vorticity transfer to the flow is then accomplished by placing the vortex elements above the surface.
It has been recognized that these vortex methods have several shortcomings. When computational methods use point vortices in their simulations, mathematical singularities can produce divergent solutions. This has been overcome by using a kernel function that contains a regularized singularity. However, this kernel function depends in certain ad hoc assumptions such as the value of the cutoff velocity and core radius. While the no-slip and no-flow boundary conditions provide information regarding the strength of the surface vorticity and subsequent strength of the vortex element, their use often neglects the effects of all other vortex sheets on the surface. Other implementations of such methods neglect the effects of coupling between the surface vortex sheets and surface sources. Finally, many methods assume a priori a separation point to analyze shedding of vorticity from the surface into the flow that generally requires experimental knowledge of the flow.
More recent prior art has utilized computer modeling based upon the nature of vortex elements at the surface of an object, such as an airfoil. These models then track the motion of each element as it moves into the flow over time to calculate the velocity of each element. While this prior art produces acceptable results, the direct calculation of the velocity of each vortex element produces an N 2 increase in the required time for processing where N is the number of vortex elements for each time step. Such increases can become unacceptable when high resolution demands the calculation of a large number of vortex elements.
SUMMARY OF THE INVENTION
Therefore, it is an object of this invention to provide an improved method and apparatus for predicting the flow of fluid past an object.
Another object of this invention is to provide an improved method and apparatus for predicting the flow of fluid past an object that is readily adapted for computer simulation.
Still another object of this invention is to provide an improved method and apparatus for predicting the flow of fluid past an object that minimizes the assumptions used in the predictions.
Yet another object of this invention is to provide an improved method and apparatus for predicting the flow of fluid past an object for a large number of points in an area of interest thereby to provide maximum resolution for the prediction.
In accordance with a method and apparatus of this invention fluid flow characteristics are predicted by defining a model of the object and defining a plurality of vorticity segments over the area of interest including vorticity segments at the surface of the object having a known velocity. In addition, there are defined over the area of interest a plurality of sets of boxes. Each set has a predetermined relationship in size and position to the boxes in the other sets. The velocity for each vorticity segment is calculated based upon the vorticity of that segment, the vorticity of each segment in the same box and in neighboring boxes and the vorticity of groups of other boxes surrounding the neighboring boxes taken collectively. Each of these velocities is summed to determine the velocity of each vorticity segment based upon the influence of all the vorticity segments in the area of interest and to provide information for displaying a representation of the fluid flow characteristics over the area of interest.
BRIEF DESCRIPTION OF THE DRAWINGS
The appended claims particularly point out and distinctly claim the subject matter of this invention. The various objects, advantages and novel features of this invention will be more fully apparent from a reading of the following detailed description in conjunction with the accompanying drawings in which like reference numerals refer to like parts, and in which:
FIG. 1 represents a line segment representation of an airfoil cross-section;
FIG. 2 depicts the geometry of a vorticity segment useful in understanding this invention;
FIGS. 3A through 3D depict a box numbering scheme that is useful in implementing this invention;
FIGS. 4 depicts, in schematic form, an apparatus embodiment of this invention; and
FIGS. 5 and 6 depict results that have been obtained using this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 depicts a representation or model 10 of a standard foil, such as an airfoil or hydrofoil, constructed by connecting 200 line segments 11 between adjacent body points 12. This particular airfoil is symmetrical in cross section and has a maximum airfoil section thickness 13 that is 15% of the length of its chord 14. The airfoil chord length has a non-dimensional length of 1.0. Body points are clustered near the leading edge 15 and trailing edge 16 of the airfoil 10 to better resolve the flow at those locations. It will apparent that similar models can also be produced to represent objects with other cross-sectional shapes.
In accordance with this invention there is defined, as an initial condition, a vorticity segment at each body point 12. FIG. 2 discloses one such vorticity segment 20 at the surface of the airfoil 10 centered at location (x p ,y p ). This vorticity segment 20 and others at the surface are infinitely thin. FIG. 2 discloses another vorticity segment 21 off the surface of the airfoil 10 at a location (x el ,y el ). This vorticity segment 21 is prescribed to have the appearance of a flat panel 22 with a finite thickness. Each such segment on the surface of the airfoil 10 carries two velocity generators, namely: (1) a surface vortex distribution lying in the plane of the segment and (2) a potential source. It is assumed that both distributions are uniform over an individual segment. The vortex strength parameter characterizing any panel is the velocity jump or change across the panel. As known, the velocity due to a potential source, α, and γ on a contour C is ##EQU1## where B n is the expression for the far-field influence of all vorticity segments in terms of a set of coefficients defining the velocity jump across panels as represented by a series of coefficients. The solution of equation (2) is well known in the art.
As will also be apparent, if an object, such as the airfoil 10 in FIG. 1, is defined by N panels, there are 2N unknowns. However, it is also required that the total velocity be zero at the control point, or centroid, of each segment. This constraint produces an equivalent number of equations. The integral of vorticity over a bounded volume is zero when the velocity goes to zero at the bounding surface. Thus the integral of the vortex strength over the body surface must also be zero. The integral of the surface potential source over the body surface must also be zero by continuity. Consequently, there exists a set of 2N+2 equations that enable a matrix solution for the surface quantities through Lagrange multipliers to that the integral constraints are met exactly and the 2N velocity boundary conditions are satisfied in a least-squares sense.
The transfer of vorticity from the surface into the flow is accomplished by the creation of rectangular vorticity elements lying just above the body surface, such a the element 21 shown in FIG. 2. After each element is produced at the surface, it moves to a position directly above the surface and has an initial thickness equal to ##EQU2## and the vorticity of the element is:
ω·dA=γ·dl (4)
where Δt is the size of the time step, ω is the element vorticity, dA is the element area, γ is the surface velocity jump on the panel and dl is the surface panel length.
Each elevated vorticity segment has the same length as the respective segment over which it lies. Therefore, each element is assigned a vortex strength based upon the velocity jump of the underlying surface panel. Its associated velocity field is determined by the Biot-Savart integral: ##EQU3##
Immediately after vorticity is shed in this fashion, minimal surface vorticity is required to satisfy the no-slip velocity boundary condition. As the elements move away from their original position through advection and diffusion, increase surface vorticity, γ, is required to meet these boundary conditions until eventually the new vorticity is shed into the flow by creation of a new family of elements. Vortex elements are shed every 0.1 non-dimensional time (t) units.
The evolution of vorticity is prescribed by the vorticity equation. In two dimensions, this equation is: ##EQU4##
The terms on the right side of equation (6) describe the change in vorticity at a point through advection and diffusion, respectively. The effect of advection is accounted for by moving element control points with the local velocity. As shown in FIG. 2, each end point is advected separately allowing for lengthening or shortening as well as rotation of the element. Since the lengths of the elements continually change, the total circulation, defined as ω ·dA must remain constant. To achieve this condition, the thickness of the element varies to keep dA constant. Since each vortex segment can infinitely stretch or compress, there is an upper limit on their maximum length. If the vortex segment exceeds this threshold length, it is split into two elements of equal length. Computational this generates a huge number of elements. As an offset, if two vortex segments cross, they are amalgamated in such a way that both linear and angular momentum is conserved. There is also a minimum thickness bound applied on the Kolmogrov length scale that is approximated as: ##EQU5## where ν is the non-dimensional kinematic viscosity and |ω| is the magnitude of the vorticity in the segment. After this minimum thickness is reached, the total area of the element is allowed to increase with a concomitant decrease in vorticity to satisfy conservation of total vorticity.
The effects of diffusion can be incorporated by the use of conventional random walk techniques that provide a standard deviation of: ##EQU6## where Δt is the time step size. It is this expression, the placement of the elements as they are shed from the surface, and minimum element thickness that are Reynolds number dependent. In non-dimensional terms, the kinematic viscosity, ν, is the inverse of the Reynolds number since both chord and freestream velocity are equal to unity.
The stepping in time of the strengths of each vorticity segment and of the segment control points is accomplished using a standard predictor-corrector scheme with one correction applied to the predictor step. Surface pressure was computed according to the method described in Uhlman, J. S., "an integral equation formulation of the equations of motion of an incompressible fluid," Naval Undersea Warfare Center Technical Report 10,086, 15 Jul. 1992. According to that method, that is based on stagnation enthalpy: ##EQU7## The first term in the first interval on the right hand side of Equation (9) accounts for any pitching motion of the air foil 10 or other object. On the surface,
U.sub.∞ +u=0.0 (11)
so
C.sub.p =1.0+2.0*H (12)
When the foregoing steps have been completed, the vorticity of every vorticity segment in an area of interest has been determined. However, as is known, the velocity vector associated with any vorticity segment is dependent not only upon the vorticity of that segment but, to various degrees the vorticity strengths of all surrounding vorticity segments. Conventional processing would involve for the determination of the velocity of any particular vorticity segment, the summation of the influence of the velocity of that vorticity segment as influenced by each of the surrounding vorticity segments. Thus, if there are N vorticity segments, a conventional conversion of vorticity to velocity would include N 2 calculations. This puts a tremendous burden on processing particularly as the resolution with the concomitant increase in the number of vorticity segments required to achieve that resolution.
However, it is also known that the influence of a second vorticity element adjacent a given vorticity segment is greater than the influence of the vorticity of another vorticity segment that is located remotely from the given vorticity segment. Stated differently, the far-field effect of any collection of vorticity segments can be expressed as a multi-pole expansion about the center of a collection of those vorticity segments whose coefficients are merely the sums of the moments of the vortex strengths about that center. This fact allows the construction of a far-field expansion for the collection solely from the knowledge of the vortex strengths and locations. As the number of vortex segments increases, this allows the far-field influence of any collection of vortex segments to be computed to any desired accuracy from a truncation of a multipole expansion.
In accordance with this method and with reference to FIG. 3A, an area of interest concerning the flow over an air foil 10 is defined by a Level 0 square box 20 that is the first level of a tree structure to distinguish vortex segments whose influence must be computed directly from those whose influence may be computed from a multipole expansion. The area of interest bounded by the Level 0 box 20 is defined as containing the complete collection of vortex segments.
The box 20 is then subdivided into a set of four equally sized Level 1 boxes as shown in FIG. 3B that are identified as BOX 2 through BOX 5. Each of these boxes is further subdivided into sixteen Level 2 boxes 22 as shown in FIG. 3C and further divided an array 23 of sixty-four Level 3 boxes as shown in FIG. 3D. If additional resolution is required, additional levels can be produced by further subdividing each successive level. As will be apparent, the number of boxes at any level is 4 L where L is the level from 0 to L max .
In accordance with this method the coefficients are computed for each of the boxes, BOX 22 through BOX 85 in the Level 3 array 23 shown in FIG. 3D. To obtain coefficients about the center of the box for a truncated multipole expansion of the vortex segments that reside in this box. Once this is accomplished, the coefficients for the truncated multipole expansion for the vortex segments in a box at the next highest level are computed about the center of this box. For example, BOX 9 in FIG. 3C corresponds to BOXES 28, 29, 36 and 37 in FIG. 3D and the coefficients generated with respect to those boxes in FIG. 3D are then used to provide a set of coefficients for BOX 9 in FIG. 3C. This step can be accomplished by simple summation and translation operations. When this procedure has been completed, truncated multipole expansions are obtained for all boxes at all levels.
Once this procedure is completed, velocities for each vortex segment are determined beginning at the second level below the largest box to define an interaction list for each box. This list identifies the boxes for which the interaction must be computed directly. For each of these boxes the coefficients of a Taylor series expansion are obtained about the center and are computed from the coefficients of the multipole expansions and are taken with respect to the center of a smaller box using recursion relationships. The process continues until the Taylor series expansions have been computed for all boxes at all levels.
Once the computation of the Taylor series coefficients is complete, the computation for the interactions begins. This proceeds by computing the direct interaction for all vortex segments in the same box as a field point and for all vortex segments in the boxes on the interaction list of that box. The interaction for all other vortex segments are then computed for the Taylor series expansion for the local box. This procedure is repeated until all desired points and the computation is then complete.
FIG. 4 depicts, in schematic block form, one embodiment of apparatus that can perform the foregoing functions. The apparatus 40 includes a series of input devices, a processing system and an output or display device. More specifically, apparatus 40 includes an object model input 41 that provides a representation of the air foil 10, a flow parameter input 42 and a resolution input 43. The flow parameter input provides information such as free stream velocity, pressure, lift and drag coefficients, Reynolds numbers, kiinematic viscosity and related parameters. The resolution input 43 establishes the maximum value of L and therefore another resolution that will used in providing the velocity representation. A processing system 44 is depicted in this particular embodiment as comprising a series of independent processors. A vorticity segment processor 45 provides the vorticity value for each vorticity segment in the area of interest shown in FIG. 3A. The box overlay processor 46 responds to information from the resolution input for providing the appropriate number of levels of boxes as shown in FIGS. 3A through 3D. A direct velocity processor 47 provides a direct velocity calculation for an individual segment and all the segments in its box and all neighboring boxes while a far field velocity processor 48 provides the approximations of velocity influence from more remote boxes as they represent the sum of all the vortex segments within a box.
A summing processor 50 combines the outputs from the direct velocity processor 47 and far field processor 58 to provide an input to a display processor 51 that can produce any of a variety of outputs on a display device 52.
It will be apparent that this structure can be implemented as a group of discrete processors performing these any other individual functions or by a general purpose computer system utilizing a variety of programs that perform the functions of the various processors shown in FIG. 4.
More specifically, the initial process begins by solving a two-dimensional vortex interaction whereby providing a two-dimensional vortex interaction solution wherein a stream function at a point (x,y) due to point vortex at (ξ, η) is given by
ψ(x,y;ξ,η)=ΓF(x,y;ξ,η) (13)
where Γ is the circulation about the vortex. The velocity components associated with this stream function are then ##EQU8##
The stream function due to a collection of these vortices is given by: ##EQU9##
Although Equations (14) and (15) could be employed to obtain expressions for the velocity components of the system shown in FIGS. 3A through 3D, in accordance with this invention an expansion of the stream function is provided by Equation (16), which yields the following far-field form: ##EQU10## Thus, Equation (16) becomes ##EQU11## It will now be apparent that the coefficients depend solely upon the circulation and location of the point vortices under consideration.
As previously indicated, it is also necessary to move the center of the expansion given above. This can be accomplished by performing a far-field expansion about the translated center (ξ 0 ,η 0 ) as ##EQU12## When the expansion ##EQU13## is applied, Equation (22) becomes ##EQU14## since s=n+p and t=m+q must remain constant. Thus ##EQU15##
In order to obtain the expansion of the field domain, or velocity, the far-field expansion about the translated center (x o , y 0 ) becomes ##EQU16## Using an expansion similar to that used in Equation (22) becomes ##EQU17## and the Taylor series expansion is then given by ##EQU18##
The summation limit L is equal to the maximum value of N less n (i.e., L=N-n). Similar methods can be used to move the center of the expansion given above. Equation (30) then is the expression for the far-field influence of all vorticity segments that is also described with reference to Equation (2).
FIG. 5 plots velocity vectors taken at vorticity element centroids as predicted in accordance with this invention. The sequence shown in FIG. 5 especially shows the adaptive nature of the boxes shown in FIGS. 3A through 3D. Higher concentrations of elements may be found in regions of high vorticity and coherent vortex structures. No vortex segments are indicative of regions of potential flow. This plot is taken for a reduced frequency of π/4 taken at different times relative to an oscillation period (t/T). At t/T=0.5, a number of vortex segments may be found near the leading edge. By t/T=0.7, however, the velocity vectors accumulate forming a dynamic stall vortex that may be seen at approximately the mid chord. By t/T=0.9 the vortex reaches the trailing edge and at t/T=0.1, these vortex segments have been shed into the wake. Accumulations of opposite vorticity may be seen nearing the trailing edge forming the trailing edge vortex. These elements advect down stream and eventually form a sinusoidal pattern in the air foil wake.
FIG. 6 shows the stream line plots for a k value of π/4 at t/T=0.5 initial formation of a leading edge vortex may be seen the quarter chord region. Unlike experimental results where only one vortex may be seen, this process predicts the formation of two leading edge vortices. The thickness of the separated region looks similar for both the predicted and experimental cases. Downstream there appears a relatively thick separated region consisting of a clockwise vorticity. By t/T=0.7, the vorticity in the separated region is shed into the wake and the leading edge vortices have combined to form a single dynamic stalled vortex which can be seen clearly at approximately 70% of the chord. Just up stream there appear to be smaller vortices in the separated region near the trailing edge. By t/T=0.9 the dynamic stalled vortex is just shed into the wake and is qualitatively similar to experimental results. By t/T=0.1, the dynamic stalled vortex is completely shed into the wake and a counter rotating trailing edge vortex can be seen. In addition the curvature of the streamline suggest an overall counterclockwise circulation about the air foil 10. This has also been observed experimentally. The flow field begins to reattach near the leading edge and continues as t/T=0.3.
These predictions track experimental results. They are obtained, however, without the need for the construction of a model and the physical testing of that model. Changing the shape of an object merely requires changing the model provided to the system. Thus this invention presents an opportunity for obtaining predictions of flow and turbulence around an air foil in an expeditious and cost-efficient manner.
This invention has been disclosed in terms of certain embodiments. It will be apparent that many modifications can be made to the disclosed apparatus without departing from the invention. Therefore, it is the intent of the appended claims to cover all such variations and modifications as come within the true spirit and scope of this invention. | A method and apparatus for predicting flow over an object such as an air l or hydrofoil. The vortex strength for each of a plurality of vortex segments is obtained over an area of interest. The vortex segments are grouped into a series of square area defined by a series of boxes having different sizes. Initially a vortex strength is established for each of the smallest boxes and the coefficients then provide characteristic vortex strengths for a given box. The conversion of these vortex strengths into velocities is accomplished by directly computing the velocity of a given vorticity segment as influenced by all the vorticity segments in the box containing the given vorticity segment and the direct influence of each vortex segment in that box and any neighboring boxes. The influence of other vorticity segments outside the neighboring boxes is provided by using the influence of the average vortex strength of a given box or group of boxes. This approach significantly reduces the number of computations required to obtain the prediction. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a continuation application of PCT/MX00/00018 filed Apr. 3, 2000, which PCT application claims priority of Mexico Application number 993220 filed Apr. 7, 1999.
TECHNICAL FIELD
[0002] The present invention relates to a trash dump that due to its special design is different from those already known, since it is more functional, more esthetic, safer, accessible and easily handled internally, as well as externally to the building where it is embedded.
BACKGROUND OF THE INVENTION
[0003] Current trash dumps, do not solve the problem of containing the trash in a functional, esthetic and simultaneously, a hygienic way. One of the issues that is not satisfied by current dumps is the esthetic, since these are only an added object to the facade and not integrated to it. Likewise, they are not functional because they do not solve the problem of an inadequate containment of the wastes, and on the other hand, they are not either hygienic, since these dumps permit access to a great number of animals, such as rodents and insects. In view of the above, the trash dump with safety collector of this invention, solves the current problems for the handling of trash, since it is a trash dump which is embedded in a wall or gate and is accessible from outside by means of an opening in the wall and it has a collector which comprises a safety system of rotatory doors which permit:
[0004] personnel of a trash collection service to pick up the trash disposed in the collector by opening a door without the need of entering the property, and even by means of some lock, if that is desired;
[0005] the user can deposit the trash inside the dump, without leaving the building by opening some particular lock;
[0006] people from outside cannot come into the building, even by entering in the trash dump.
[0007] Likewise, since it is a dump which is kept hermetically closed, it will be free of animals and insects, impermeable and will not give off bad odors to the outside or within the building. In addition, it is durable because it is not subject to the inadequate handling and it will not obstruct the public way.
SUMMARY OF THE INVENTION
[0008] The present invention refers to a trash dump which solves and satisfies the current needs, since such a dump can be embedded in the wall of a house, in the gate or in some other place enabling the people who live in the house can deposit the trash in the respective dump inside, instead of going out from the building, and the people in charge of the trash collection to pick up the trash from outside. This new trash dump has a safety doors system which allow the easy handling and make it safer, since it prevents the introduction into the house of the people who collect the trash.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The details of the features of this invention are shown in the following description and in the attached drawings, serving the reference numbers therein to denote the parts shown in the Figures.
[0010] [0010]FIG. 1 is a perspective view of the front-side part of the trash dump with safety collector;
[0011] [0011]FIG. 2 is a perspective view of the rear-lateral part of the trash dump with safety collector;
[0012] [0012]FIG. 3 is a plan view of a front cut of the dump, which shows how the doors of the safety collector are disposed over the lateral axes;
[0013] [0013]FIG. 4 is a perspective view of the front-side part of the trash dump where the side lid has been removed, allowing viewing of the mechanism, this view being identical at the opposite side.
[0014] [0014]FIG. 5 is a view similar to FIG. 4, but with the external door opened by mean of an actuating handle;
[0015] [0015]FIG. 6 is a perspective view of the rear-side part of the trash dump, showing an internal door which closes access to the inside of the building;
[0016] [0016]FIG. 7 is a perspective view of the front-side part of the trash dump, wherein the side door has been removed, allowing viewing of the pedal mechanism that actuates the internal doors;
[0017] [0017]FIG. 8 is a perspective view of the rear-side part of the trash dump, where the actuating pedal for actuating the rear and inside doors can be seen; and
[0018] [0018]FIG. 9 is a front perspective view of the trash dump installed in a wall, as seen from the street.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Referring in detail to the drawings, and initially to FIGS. 1 and 2, they show a preferred embodiment of the trash dump with safety collector 10 according to this invention. It includes a section for the extraction of trash 1 which comprises a header with walls disposed in a truncated cone shape; a section for placing the trash which makes up the longitudinal part of the collector 10 ; a section for the introduction of the trash 3 , and a side section 4 for the access to the internal mechanism of the collector 10 .
[0020] [0020]FIG. 3 shows a cross section cut of the front part of the trash dump 10 , which shows the parts that make up the internal doors system of the dump. This system is supported by an internal lid 5 and an external lid 15 , so that a support 11 is placed on the external face of the internal lid 5 , made of a metallic trip. All of the parts are joined by welding, so that it has a configuration with the shape of an inverted V (see FIGS. 4 through 8) and the support is joined to the peripheral part of the body 2 of the dump 10 (see FIG. 6).
[0021] An axis 9 is disposed fixed to the top of each support 11 perpendicularly, so that the axis supports, and at the same time, allows the oscillatory movement of a first external door 6 , a rear door 7 and an internal door 8 .
[0022] The actuation of the doors 7 and 8 is carried out by the mechanism located in the side parts of the trash dump, which are discussed below. The external door 6 has a convex shape having side walls, which are embedded in each of the axes 9 . The door is actuated said door by a handle 17 that is joined to the external face of the sides, so that the person collecting trash only moves the handle 17 upwardly to allow access to the inside of the dump, and moves the handle downwardly for closing the dump. For safety purposes, the door 6 has attached a pair of pivot springs 12 for causing self-closing of said door. The springs are supported by axes 9 so that one leg of the spring makes contact with the internal side face which includes the door 6 and the other leg of the spring 12 makes contact with the support means 11 .
[0023] The bumper mean 28 , are also illustrated in FIG. 3. They comprise a pair of flanges of curved configuration, whose function is to prevent the external door 6 and the rear door 7 from being opened at the same time. The operation of the bumper mean is discussed below. A second support with an L-shape to support a bag of trash 14 , is disposed on the internal face of the internal side wall 5 . A drainage plug 16 is disposed at the bottom part of the trash dump 10 , to allow the leakage of fluids for the internal washing of the dump. A strap 18 coupled within the slot formed in the body of the dump is disposed at the top of the dump and serves as a stand for a safety lock (not shown).
[0024] [0024]FIGS. 4 through 8 show the operation of doors 7 and 8 , which are located on each side of the trash dump 10 , as well as the internal mechanism of the dump. A part of the header 1 , shown with reference numeral 35 , is a part of the trash dump and it is useful to be assembled in an opening (not shown) within a wall. A mechanism for the actuation of doors 7 and 8 is shown, and FIG. 4 shows the trash dump 10 in a state without actuating. The mechanism is comprised basically of a pair of rods 21 and 22 . At the lower part, the rods join together to a first end of an actuating lever 20 , so that this lever is supported by a pedal support 30 which serves as the point of support. The actuating lever 20 is moved upwardly and downwardly in relation to the rods. The second end of the actuating lever 20 protrude from the dump 2 through a pair of slots 32 (see FIG. 6). A wide plate 19 is attached in the ends and it functions as an actuating pedal.
[0025] Spring mean are adjacent to the pedal support 30 , wherein the spring 23 comprises a small resilient stem. One end of said stem is joined to the body of the pedal support 30 and the other end of the stem only makes contact with a bumper 33 . The bumper is joined to the external face of the side wall 5 by welding. The second spring 24 is placed at the top, next to the stem spring 23 , and this one operates as a bumper for the actuation lever, when a force is applied on the pedal 19 .
[0026] One of the side walls of the internal door 8 is joined to the top of the bar 21 by a pin to permit the upward and downward movement of the door. The bar 22 is identified as a “stick” type bar that is joined to the external side wall of the door 7 by the second pin means, so that that door is also moved upwardly and downwardly.
[0027] As mentioned before, FIG. 4 shows each of the doors when they are not actuated. FIG. 5 shows the raising of the door 6 but without actuating the doors mechanism. FIG. 6 shows the doors without actuating. The safety means 25 can also be seen, wherein the said safety means comprises a latch or lock placed over the flange 18 to prevent raising of the door 6 . This is accomplished by a key (not shown) which actuates the pin of the lock or latch. This pin penetrates in a hole (not shown) disposed at the top of the trash dump 10 , and prevents in this way the introduction of to the inside of the trash dump of strange people or simply the introduction of any object when nobody is inside the building. FIG. 7 shows the same FIG. 4 , but with the door 6 opened. One of the internal side circular walls of door 8 can also be seen with the head of axis 9 , which allows the oscillatory movement of same.
[0028] [0028]FIG. 8 shows the actuation of doors 7 and 8 when the pedal 19 is pushed downward. This causes the actuating lever 20 joined to the pedal to move the bars 21 and 22 upwardly, to cause the rotatory movement of the doors over axis 9 , causing the door 7 to tend to turn clockwise and causing the circular walls of the internal door 8 to turn counter clockwise.
[0029] Introducing the trash inside the dump 2 is done as follows. First, before actuating the pedal 19 downwardly, there is a radial sectional part 36 of door 8 , which serves as a support for the trash (see FIG. 3). This sectional part 36 is in an overlapped position at the same distance of the rear part of section 3 of the dump 20 . When pushing pedal 19 , the door 7 turns upstream and the radial section 36 of door 8 tends to go downstream, so that the spring 24 functions as a bumper for the turn limit of both doors. Then the radial section 36 is placed in a transverse position. In that moment, the user can place the trash over the same.
[0030] Once the trash has been placed on the radial section 36 of door 8 , the user can stop applying force on the pedal 19 , which causes the return of the internal and rear doors, by the pushing action of the springs 23 and 24 over the actuating lever 20 . At that moment, the trash falls by gravity inside the bag for the collection of trash 14 .
[0031] As mentioned above, the bumper means 28 , comprise a pair of flanges of curved configuration, which function as safety means. When an individual from outside wishes to get into the building, both the external door 6 and the rear door 7 must be actuated at the same time to provide a passage for entering the building. In order to prevent this, a pair of flanges 28 is disposed, one on each side of the internal side wall that forms part of door 6 . When both doors 7 and 6 are actuated at the same time, the stick type bars 22 make contact with the flanges 28 . This causes both doors to be opened only for a relatively short distance, and in this way, it is avoided any intrusion.
[0032] As an example, in FIG. 9, the trash dump 10 is installed in a wall 37 . There the embedded header of the dump provides it a pleasant and hygienic appearance and avoids the entry of animals.
[0033] Although the present invention has been described in relation to a particular embodiment thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited to not by the specific disclosure herein, but only by the appended claims. | The present invention refers to a trash dump which solves and satisfy the current requirements. The new trash dump is embedded to a wall or gate or to any other place where can be used. This new trash dump has the peculiarity that the user can deposit the trash inside the dump without going out from the building and the personnel of the trash collection service, can pick the trash disposed in the collector up through an opening in the wall, which has a collector with a safety system of rotatory doors. Said safety system allows, at the same time, the easy operation of the trash dump and avoids any intrusion. | 8 |
BACKGROUND OF THE INVENTION
Internal combustion engines often utilize fuel injection systems rather than the typical carburation system. Such fuel injection systems can utilize an additional air pump to provide pressurized air which is mixed with fuel internally within the fuel injector and the fuel/air mixture is injected into the combustion chamber of the cylinder. It is desirable to provide higher speed of operation of the injector at relatively low pressures while obtaining proper atomization of the fuel.
The present invention provides a fuel injector that operates at low pressure and directly feeds the fuel into an air stream directed into the combustion chamber. The fuel is thus broken up into smaller particles from the beginning to the end of the cycle.
The present invention provides a fuel injector satisfactory for directly injecting fuel into the cylinder of a two-cycle, spark ignition engine operating over the speed range of typical outboard motors.
SUMMARY OF THE INVENTION
A fuel injector for an internal combustion engine includes a body which extends into the combustion chamber of the cylinder and which has an air inlet port and a fuel inlet port leading to a pair of passageways that terminate in an air outlet port and a fuel outlet port located within the combustion chamber.
In accordance with yet another aspect of the invention, the fuel injector is provided with a first valve which moves between an open and closed position in which the air outlet port is alternately open and closed.
In accordance with yet another aspect of the invention, the fuel injector is provided with a second valve which moves between a first and second position in which the fuel outlet port is alternately open and closed.
In accordance with still another aspect of the invention, the fuel injector is provided with an actuator which moves the two valves between their open and closed positions and which controls the sequence such that the air valve is opened prior to the opening of the fuel valve and upon closing the fuel valve is closed prior to the closing of the air valve. This sequencing is provided so that when fuel is introduced into the combustion chamber it is introduced directly into the path of an airflow and the airflow is continued for a short time period after the fuel flow has been discontinued.
In accordance with yet another aspect of the invention, the fuel injector is provided with an adjustment that allows the timing of the operation of the valves to be varied.
The present invention thus provides a fuel injector that directly introduces fuel into an air stream in the combustion chamber and which operates at low pressures.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings illustrate the best mode presently contemplated of carrying out the invention.
In the drawings:
FIG. 1 is a cross sectional view of a cylinder in an internal combustion engine utilizing the fuel injector of the present invention;
FIG. 2 is a side cross sectional view of the fuel injector;
FIG. 3 is a side cross sectional view of the lower portion of the fuel injector;
FIG. 4 is an enlarged side cross sectional view of the fuel injector of FIG. 3 with the air and fuel outlet ports shown closed by their associated valves;
FIG. 5 is a side cross sectional view of the lower portion of the fuel injector with the valve for the air outlet port shown in the open position;
FIG. 6 is an enlarged side cross sectional view of the fuel injector of FIG. 5 with the valve for the air outlet shown in its open position; and
FIG. 7 is an enlarged side cross sectional view of the fuel injector with both the air and fuel outlet ports shown in their open position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIG. 1, a fuel injector 10 is provided with a body 12 having an upper portion 14 that has an air inlet port 16 and a fuel inlet port 18. Body 12 is also provided with a lower portion 20 that is inserted into an opening in engine cylinder 22 and is provided with an air outlet port 24 and a fuel outlet port 26 that communicate directly with combustion chamber 28. The upper portion of engine cylinder 22 is also provided with an opening that accommodates spark plug 30. The illustrated engine is a two-cycle engine having air inlet ports in the cylinder wall to supply air as the air inlet ports and are uncovered by the piston, not illustrated. In the particular embodiment, the exhaust is also through piston controlled ports in the cylinder wall.
As shown in FIG. 2, fuel inlet port 18 communicates with horizontal passageway 32 which in turn communicates with vertical passageway 34 that extends downwardly through fuel injector body 12 and eventually communicates with angular passageway 36 that terminates in fuel outlet port 26.
Air inlet port 16 communicates directly with internal vertical passageway 40 which is comprised of the interior of tubular member 42. Tubular member 42 consists of an upper portion 44 and a lower portion 46 which are connected by means of a bellows arrangement 48.
Bellows 48 allows for vertical sliding movement of lower portion 46 while upper portion 44 is allowed to remain stationery.
Disposed within injector body 12 and surrounding tubular member 42 is solenoid 50. Energization of solenoid 50 results in a downward force on tubular member 42 causing tubular member 42 to slide downwardly within fuel injector body 12.
As best seen in FIGS. 5 and 6, tubular member 42 terminates in a frusto conical end piece 52 which serves to seal air outlet port 24 when tubular member 42 is in its retracted position. When tubular member 42 is in its extended position as shown in FIGS. 5 and 6, end piece 52 extends outwardly from injector body 12 and air from vertical passageway 40 is allowed to pass through sidewall openings 54 in tubular member 42 and out through air outlet port 24 and into combustion chamber 28.
A second tubular member 56 is slidably disposed around first tubular member 42 and has its lower end terminating in an outwardly and downwardly extending lip 58.
When tubular member 56 is in its retracted position as shown in FIGS. 5 and 6, lip 58 is seated against injector body 12 and closes fuel outlet port 26. When second tubular member 56 is in its extended position, lip 58 extends downwardly beyond injector body 12 so as to open fuel outlet port 26 and allow fuel to flow from angular passageway 36 and out through fuel port 26 and into combustion chamber 28. The frusto conical shape of end piece 52 causes the airflow from air outlet port 24 to be directed at an angle to the fuel flow from fuel port 26 thus resulting in the atomization of the fuel in combustion chamber 28.
The outer surface of the upper portion of tubular member 42 is provided with thread 60 onto which a nut 62 is rotatably disposed. Nut 62 provides a shoulder 63 that extends radially from the upper portion of tubular member 42. Extension of tubular member 42 by solenoid 50 eventually causes nut 62 to come into engagement with upper edge 64 of second tubular member 56. The position of nut 62 thus limits the extent of opening of air port 24. Upon engagement, any further extension of first tubular member 42 results in a corresponding extension of second tubular member 56. The length of extension through which first tubular member 42 can travel before engaging second tubular member 56 and causing its movement can be varied by rotating nut 62 on thread 60. A locking nut 65 is provided to secure nut 62 in the desired position.
The extent of opening of fuel port 26 is adjustably controlled by the position of spring seat 68 relative to lower portion 20. The position of the spring seat 68 can be adjusted by means of the threaded engagement with lower portion 20. Turing spring seat 68 further into lower portion 20, as shown in FIG. 2, will increase the gap 71 between the abutment 43 formed on tubular member 42 and lower portion 20. Increasing the gap 71 allows increased movement of tubular member 42 and thus increased opening of fuel port 26.
The interior of injector body 12 is provided with a main spring 66 which is contained between spring seat 68 and spring retainer 70 that is connected to and extends outwardly from second tubular member 56. Main spring 66 provides a biasing force on second tubular member 56 that urges tubular member 56 to its retracted position.
Similarly, a secondary spring 72 is disposed between spring retainer 70 and the bottom surface of nut 62. Secondary spring 72 provides a biasing force that urges first tubular member 42 to its retracted position.
In operation and as shown in FIGS. 3 and 4, both tubular members 42 and 56 are in their retracted positions and lip 58 has sealed fuel outlet port 26 and end portion 52 has sealed air outlet port 24. In these retracted positions, there is a space between nut 62 and upper edge 64 of second tubular member 56.
In FIGS. 5 and 6, solenoid 50 has been energized and first tubular member 42 is partially extended to the point where the space between nut 62 and upper edge 64 of second tubular member 56 has been closed. In this position, end portion 52 has extended outwardly from lip 58 where it was seated so as to open air outlet port 24 and allow the flow of air from vertical passageway 40, through outlet port 24 and into combustion chamber 28. Second tubular member 56 has yet to be extended since nut 62 has just come into contact with upper edge 64 and therefore fuel outlet port 26 remains closed by lip 58. Thus air port 24 will open prior to fuel port 26.
In FIG. 7, first tubular member 42 has been further extended and this further extension has resulted in the extension of second tubular member 56 due to the downward force of nut 62 on upper edge 64 of second tubular member 56. In this position, lip 58 has extended beyond injector body 12 and fuel is allowed to pass from angular passageway 36 through fuel outlet port 26 and into combustion chamber 28. As the fuel flows into combustion chamber 28 it is atomized by the flow of air from outlet port 24. Preferably with both ports 24 and 26 open, the air outlet port 24 will define a conical airflow having a cone angle of approximately 90°, while the fuel port 26 will define a conical fuel flow pattern of approximately 60°. The intersection of the fuel and air flows will thus provide the desired atomization.
When solenoid 50 is de-energized, the biasing force of springs 66 and 72 will urge first tubular member 42 and second tubular member 56 into their retracted positions. It can be seen that lip 58 will return to its seated position against injector body 12 prior to end portion 52 returning to its seated position against lip 58. Thus, the flow of fuel through fuel outlet port 26 will be terminated slightly before the flow of air through air outlet port 24. This initiation of the airflow prior to the introduction of fuel and the continuation of the airflow after the discontinuance of the fuel flow is desirable in that it insures that the fuel will be broken up into smaller particles from the beginning to the end of the fueling cycle.
It is recognized that various alternatives and modifications are possible in the scope of the appended claims. | A fuel injector for an internal combustion engine includes a body having fuel and air inlet ports and fuel and air outlet ports located within the combustion chamber of the engine cylinder. A pair of valves open and close the air and fuel outlet ports and are sequenced so that fuel is introduced into a flow of air and the flow of air continues briefly after the fuel flow has been discontinued. | 5 |
RELATED APPLICATIONS
[0001] This application claims the benefit of provisional patent application Ser. No. 62/360,558, filed Jul. 11, 2016, the disclosure of which is hereby incorporated herein by reference in its entirety.
FIELD OF THE DISCLOSURE
[0002] The present disclosure is directed to improving performance characteristics of acoustic wave devices.
BACKGROUND
[0003] In acoustic wave device technology a first metal layer is a patterned aluminum-based material layer known as an interdigital transducer (IDT) metal layer. Typically, an IDT metal layer comprises aluminum (Al) and a relatively smaller amount of titanium (Ti). The aluminum dominates the composition of the IDT metal layer because it has a higher ratio of conductivity to mass than titanium. The conductivity-to-mass ratio is a relatively critical characteristic for acoustic wave devices because a higher conductivity-to-mass ratio yields a lower insertion loss for radio frequency filters constructed from acoustic wave devices.
[0004] While aluminum is a desirable component of IDT metal, aluminum is not ideal because aluminum oxidizes readily when exposed to oxygen in air to form aluminum oxide. However, the oxidation of aluminum is typically self-limiting such that the formation of the oxide layer prevents additional oxidation of the aluminum metal making up the IDT metal layer. The oxide layer becomes detrimental at locations on the acoustic wave device where it is necessary to connect additional metal layers to the IDT metal layer.
[0005] In lithium tantalate surface acoustic wave (LTSAW) technology used to make a subset of acoustic wave devices, a second metal layer most often in contact with the IDT metal layer is an under bump metallurgy (UBM) metal. This second metal layer is deposited to form appropriate circuit connections for the acoustic wave device and is composed of Ti/Al/Ti. However, an aluminum oxide (AIO) layer formed on the IDT layer is insulating and is chemically and physically robust such that etching vias to connect the UBM to the IDT metal layer is not effective at removing the AIO layer. In addition to the robustness of the AIO layer, LTSAW process flow requires exposure of the aluminum IDT metal layer to ambient air during operations prior to UBM evaporation, which allows for re-oxidation of aluminum in any areas exposed by removal of the AIO during processing. The insulating nature of the AIO layer prevents consistent, low direct current (DC) contact resistance between UBM and the IDT metal layer. This AIO insulating layer also increases insertion loss by limiting conductivity between UBM and IDT layers. The lack of DC contact makes process control monitoring difficult because most process control monitoring is performed by DC measurement of test structures. The AIO between the UBM and the IDT metal layer also adds additional capacitance to radio frequency test structures, which can complicate parameter extraction and modeling. In addition to negative effects on electrical characteristics of acoustic devices, the AIO layer can also affect the mechanical properties of acoustic devices. The AIO layer prevents metal-to-metal contact between the IDT metal layer and the UBM. Therefore, adhesion between the IDT metal layer and the UBM is reduced. This reduction in adhesion reduces shear strength between the IDT metal layer and the UBM. As such, the robustness of acoustic devices during assembly is reduced by mechanical stresses of assembly. Thus, there is a need for acoustic devices that do not have AIO layers formed between the UBM and IDT layers.
SUMMARY
[0006] Disclosed is a device that includes a crystalline substrate and a patterned aluminum-based material layer disposed onto the crystalline substrate. The patterned aluminum-based material layer has a titanium-alloyed surface. A titanium-based material layer is disposed over select portions of the titanium-alloyed surface.
[0007] In an exemplary embodiment, the patterned aluminum-based material layer forms a pair of interdigitated transducers to provide a surface acoustic wave (SAW) device. The SAW device of the present disclosure is usable to realize SAW-based filters for wireless communication equipment.
[0008] Another aspect of the disclosure provides a method of fabricating the device. In general, the method includes a process step of disposing a patterned aluminum-based material layer onto a crystalline substrate. Another process step includes disposing a titanium-based material layer over the patterned aluminum-based material layer. Yet another process step includes selectively etching away portions of the titanium based material layer to leave an exposed titanium-alloyed surface on the portions of the patterned aluminum-based material layer.
[0009] In at least one exemplary embodiment another step includes disposing an under bump metallurgy layer comprising a metal directly in contact with the portions of the titanium-alloyed surface. The resulting contact resistivity is in the range of 1×10 −8 ohm (Ω)/cm 2 and 1×10 −7 Ω/cm 2 .
[0010] Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0011] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.
[0012] FIG. 1 is a perspective drawing of an acoustic device of the present disclosure.
[0013] FIG. 2 is a cross-sectional view of a completed portion of one embodiment of the acoustic device of the FIG. 1 .
[0014] FIG. 3 is a cross-sectional view of a result of beginning steps completed for fabricating the portion of the embodiment of the acoustic device depicted in FIG. 2 .
[0015] FIG. 4 is a cross-sectional view of a result of a step that involves disposing a crossover pattern that will in later steps provide support for a bridging portion of an under bump metallurgy (UBM) layer.
[0016] FIG. 5 is a cross-sectional view of a result of another step that involves disposing the passivation layer onto the titanium-based material layer, the crossover pattern, and exposed sections of the substrate.
[0017] FIG. 6 is a cross-sectional view of a result of another step that involves disposing a photoresist mask over portions of the patterned aluminum-based material layer and titanium-based material layer.
[0018] FIG. 7 is a cross-sectional view of a result of another step that involves etching away portions of the passivation layer and titanium-based material layer to leave regions of the titanium-alloyed surface exposed.
[0019] FIG. 8 is a cross-sectional view of a result of another step that involves disposing the UBM layer onto the exposed titanium-alloyed surface and the crossover pattern.
[0020] FIG. 9 is a cross-sectional view of a result of a final step that involves lifting off the photoresist mask and unwanted portions of the UBM layer.
DETAILED DESCRIPTION
[0021] The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.
[0022] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0023] It will be understood that when an element such as a layer, region, or substrate is referred to as being “on” or extending “onto” another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or extending “directly onto” another element, there are no intervening elements present. Likewise, it will be understood that when an element such as a layer, region, or substrate is referred to as being “over” or extending “over” another element, it can be directly over or extend directly over the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly over” or extending “directly over” another element, there are no intervening elements present. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
[0024] Relative terms such as “below” or “above” or “upper” or “lower” or “horizontal” or “vertical” may be used herein to describe a relationship of one element, layer, or region to another element, layer, or region as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures.
[0025] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used herein specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0026] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0027] FIG. 1 is a perspective drawing of the acoustic wave device 10 of the present disclosure. The acoustic wave device 10 includes a crystalline substrate 12 , such as lithium tantalate (LiTaO 3 ) or lithium niobate (LiNbO 3 ), onto which an interdigital transducer layer that is a patterned aluminum-based material layer 14 is disposed. In the exemplary embodiment of FIG. 1 , the patterned aluminum-based material layer 14 has a pattern of interdigitated fingers. Additional elements such as acoustic reflectors 16 are included on acoustic devices such as surface acoustic wave (SAW) resonators. An exemplary acoustic wave device 10 is depicted as a SAW resonator that is typically coupled with other SAW resonators to form SAW filters that are used in wireless products such as smart phones.
[0028] FIG. 2 is a cross-sectional view of a completed portion of one embodiment of the acoustic wave device 10 . As in FIG. 1 , the patterned aluminum-based material layer 14 is disposed onto the crystalline substrate 12 . In at least one embodiment the patterned aluminum-based material layer 14 is at least 99% aluminum. In other embodiments, the patterned aluminum-based material layer 14 is an aluminum alloy. In some embodiments, the aluminum alloy is an aluminum/copper alloy.
[0029] In addition, the patterned aluminum-based material layer 14 has a titanium-alloyed surface 18 that is formed during fabrication of the acoustic wave device 10 as portions of a titanium-based material layer 20 are etched away. The remaining portions of the titanium-based material layer 20 are protected from etching by a photoresist during subsequent processing.
[0030] The titanium-based material layer 20 is disposed between 10% and 90% of the titanium-alloyed surface 18 . In yet other embodiments, the titanium-based material layer 20 is disposed between 10% and 75% of the titanium-alloyed surface 18 . In yet other embodiments, the titanium-based material layer 20 is disposed between 10% and 50% of the titanium-alloyed surface 18 . In at least one embodiment, the titanium-based material layer 20 is 99% titanium. In other embodiments, the titanium-based material layer 20 is a titanium alloy. In at least some embodiments, the titanium alloy making up the titanium-based material layer 20 is titanium/aluminum.
[0031] In some embodiments, the titanium-based material layer 20 has a thickness that is in the range of 20 angstroms (Å) to 50 Å. In other embodiments, the titanium-based material layer 20 has a thickness that is in the range of 50 Å to 70 Å. In yet other embodiments, the titanium-based material layer 20 has a thickness that is in the range of 70 Å to 100 Å. In still yet other embodiments, the titanium-based material layer 20 has a thickness that is in the range of 100 Å to 500 Å.
[0032] An under bump metallurgy (UBM) layer 24 is made up of a metal disposed directly onto portions of the titanium-alloyed surface 18 of the patterned aluminum-based material layer 14 not covered by the titanium-based material layer 20 . In some locations a crossover pattern 26 provides support for a bridging portion 28 of the UBM layer 24 . Contact resistivity between the metal of the UBM layer 24 and the titanium-alloyed surface is in the range of 1×10 −8 and 1×10 −7 ohm (Ω)/cm 2 .
[0033] FIG. 3 is a cross-sectional view of a result of beginning steps completed for fabricating the portion of the embodiment of the acoustic wave device 10 depicted in FIG. 2 . A first step is disposing the patterned aluminum-based material layer 14 onto the crystalline substrate 12 (step 100 ). A next step is disposing the titanium-based material layer 20 directly onto the patterned aluminum-based material layer 14 (step 102 ). The thickness of the titanium-based material layer 20 is controlled throughout the deposition step such that the titanium-based material layer 20 has an ultimate thickness that is selectively in the range of 20 Å to 500 Å.
[0034] FIG. 4 is a cross-sectional view of a result of a next step that involves disposing the crossover pattern 26 that in later steps provides support for the bridging portion 28 of the UBM layer 24 (step 104 ). In an exemplary embodiment, the crossover pattern is made of photo definable polymer. Other suitable materials for the crossover pattern include, but are not limited to, silicon oxide, silicon oxynitride, and other dielectrics with a permeability below 5.
[0035] FIG. 5 is a cross-sectional view of a result of another step that involves disposing the passivation layer 22 onto the titanium-based material layer 20 , the crossover pattern 26 , and exposed sections of the crystalline substrate 12 (step 106 ). In some embodiments, the passivation layer 22 is made of SiO 2 and in other embodiments the passivation layer is made of SiN or a bilayer of SiO 2 and SiN.
[0036] FIG. 6 is a cross-sectional view of a result of another step that involves disposing a photoresist mask 30 over portions of the patterned aluminum-based material layer 14 and titanium-based material layer 20 (step 108 ). The photoresist mask 30 defines interconnect metal regions that are occupied by the UBM layer 24 in subsequent steps.
[0037] FIG. 7 is a cross-sectional view of a result of another step that involves etching away portions of the passivation layer 22 and the titanium-based material layer 20 to leave regions of the titanium-alloyed surface 18 exposed (step 110 ). The passivation layer 22 is also etched from the crossover pattern 26 during the etching process. Techniques for etching away portions of the titanium-based material layer 20 are those commonly employed in passivation etching processes.
[0038] FIG. 8 is a cross-sectional view of a result of another step that involves disposing the UBM layer 24 onto the exposed titanium-alloyed surface 18 and the crossover pattern 26 (step 112 ). The UBM layer 24 is typically made of metals such as a titanium and aluminum or titanium and gold. Contact resistivity between the metal of the UBM layer 24 and the titanium-alloyed surface is in the range of 1×10 −8 and 1×10 −7 Ω/cm 2 .
[0039] FIG. 9 is a cross-sectional view of a result of a final step that involves lifting off the photoresist mask 30 ( FIG. 6 ) and unwanted portions of the UBM layer 24 (step 114 ). At this point, the acoustic wave device 10 ( FIG. 1 ) is complete and ready for testing. The acoustic wave device 10 typically has an absolute value of insertion loss that is no more than 2 dB. However, depending on the ultimate function of the acoustic wave device 10 , whether it is employed as a filter component or a sensor component determines the boundaries of insertion loss, which can range from 0.1 dB to 10 dB.
[0040] Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow. | Disclosed is a device that includes a crystalline substrate and a patterned aluminum-based material layer disposed onto the crystalline substrate. The patterned aluminum-based material layer has a titanium-alloyed surface. A titanium-based material layer is disposed over select portions of the titanium-alloyed surface. In an exemplary embodiment, the patterned aluminum-based material layer forms a pair of interdigitated transducers to provide a surface wave acoustic (SAW) device. The SAW device of the present disclosure is usable to realize SAW-based filters for wireless communication equipment. | 7 |
BACKGROUND OF THE INVENTION
Heating and air conditioning systems for residences, industrial factories, and office buildings involve large cross-sectional header pipes, usually rectangular insulated sheet metal tubular structures, and a large number of smaller branch lines, usually round insulated sheet metal tubular pipes, leading to vents to distribute the heated or cooled air to the desired spaces inside the building. The typical prior art structure for connecting the branch line to the header involves inserting a short length of pipe into a hole cut in the header to receive the pipe, and fastening the pipe in place by any of a variety of means, and then covering all exposed metal surfaces with a suitable insulation. One means for fastening may involve L-shaped brackets attached to both the header and the pipe with bolts and nuts. Another means is to employ a pipe connection with dovetail cut-out fingers on the end which is inserted into the header, and manually bending the dovetails outward to hold the pipe in place. None of these procedures and structures is entirely satisfactory because the resulting connection is so loose that too much air is lost by leakage.
It is an object of this invention to provide an improved device for connecting branch lines to header lines in air conducting systems. It is another object of this invention to provide a tight connection which eliminates leaks in air conductor piping. Still other objects will become apparent from the more detailed description which follows.
BRIEF SUMMARY OF THE INVENTION
This invention relates to a ring seal collar for air ducts which comprises a thin walled tubular conduit body having an inlet end and an outlet end and an L-shaped channel ring having a bottom leg and an outer leg extending substantially parallel to the conduit body intermediate the ends with the bottom leg of the channel located adjacent the inlet end and the open side of the channel located adjacent the outlet end. The bottom leg has a plurality of spaced holes to receive fasteners for attachment of the collar to a main header of a heating and/or air conditioning system. In specific preferred embodiments of this invention the collar is a sheet metal structure tapered at the outlet end to slide into a tubular member and contains two circumferential recesses, one around the body adjacent the channel ring and the other around the outer leg of the channel ring, both recesses adapted to receive keeper belts, commonly termed "tie straps".
The invention also involves a system for attaching an insulated side branch conduit to a main header of heating and air conditioning distribution system, which comprises the steps of:
(a) cutting a hole in the main header to receive the side branch conduit;
(b) inserting into the hole the inlet end of a ring seal collar having a thin walled tubular conduit body with an inlet end and an outlet end and having rigidly affixed to and around the outside of the conduit a channel ring having an L-shaped cross section with a bottom leg and an outer leg forming a closed side and the outer leg and conduit forming an open side of the channel formed between the conduit and ring, the inner leg being rigidly affixed to the conduit and the closed side facing the inlet end, the bottom leg having a plurality of spaced holes therethrough;
(c) inserting and tightening screws in the spaced holes to clamp the channel ring tightly against the header;
(d) placing over the outlet end a length of tubular insulation having an inner core layer and an outer cover layer with an insulation layer sandwiched therebetween;
(e) peeling back the cover layer and the insulation layer and fastening the inner core layer around the tubular conduit body by tightening a first keeper belt therearound;
(f) inserting the insulation layer into the channel ring to fill the ring completely with the insulation layer; and
(g) placing the cover layer around the outside leg of the channel ring and fastening it to the channel ring by tightening a second keeper belt therearound.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a top plan view of the ring seal collar of this invention;
FIG. 2 is a front elevational view, partially in cross section, of the ring seal collar of FIG. 1;
FIG. 3 is a side elevational view of a first step in attaching the ring seal collar to a header conduit of duct board;
FIG. 4 is a side elevational view of an initial step in attaching a hollow insulation member to the ring seal collar of FIG. 3;
FIG. 5 is a side elevational view of the next step in attaching the insulation member of FIG. 4;
FIG. 6 is a side elevational view of the final step in attaching the insulation member of FIG. 5;
FIG. 7 is a side elevational view of a first step in attaching the ring seal collar of this invention to a sheet metal header conduit;
FIG. 8 is a side elevational view of the next step in attaching the ring seal collar in FIG. 7; and
FIG. 9 is a cross sectional view of the area identified as 9 in FIG. 2 on an alternate embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The principal features of the ring seal collar of this invention are best understood by reference to the attached drawings.
In FIGS. 1 and 2 the ring seal collar and its structure is shown. The collar preferably is made of sheet metal and includes two separate component portions that are affixed to each other to produce a single unitary device. The ring seal collar or either of its component portions may be made of plastic or other suitable material, but sheet metal is preferred. The two portions are a conduit body 20 and a channel ring flange 25. Conduit body 20 essentially is a short section of conduit (e.g., 6-inch pipe) having an inlet end 21 to fit into a header conduit and an outlet end 22 to connect to other lengths of insulated or noninsulated conduit. At outlet end 22 the conduit body is tapered by crimping at 23 to provide an easy insertion into the next section of conduit.
Ring flange 25 provides a U-shaped channel around the outside of conduit body 20 to function as a seat for a section of insulated conduit 34 (see FIGS. 3-6). Ring flange 25 has an outer leg 26, an open side 28 and a closed side 29. Inner leg 27 of the channel cross-section is provided by a portion of conduit body 20. Ring flange 25 may be an L-shaped structure (as shown in FIG. 2) or a U-shaped structure (as shown in FIG. 9) Both alternatives are acceptable and differ only in the method of attachment to conduit body 20. In the case of the L-shaped structure of FIG. 2, ring flange 25 has an inside edge 53 which fits into bead 45 formed on conduit body 20. No further fasteners are needed to hold flange 25 in place. In the case of the U-shape structure of FIG. 9, inside leg 27 of the channel is affixed to conduit body 20 by adhesive or spot welding, either being acceptable. The end of ring flange 25 is tapered by crimping at 48 to provide for easier reception thereabout of part of the insulated conduit 34.
Ring flange 25 is positioned intermediate inlet end 21 and outlet end 22 with closed side 29 adjacent inlet end 21 and open side 28 facing in the same direction as outlet end 22. Closed side 29 is positioned so as to leave a short portion 49 of conduit body 20 extending below closed side 29. Short portion 49 is inserted into a hole in the header conduit with closed side 29 flush against the header conduit for easy attachment of ring flange 25 and the entire ring seal collar to the header conduit.
There are two circumferential recesses around each ring seal collar for use in attaching an insulated conduit to the collar. One recess 24 is around conduit body 20 between flange 25 and tapered corrugated portion 23 at the outlet end 22. The other recess 30 is around outer leg 26 of ring flange 25. These recesses 24 and 30 are fashioned to function as seats for keeper belts (50 and 51 in FIGS. 4 and 6). Typically these keeper belts are thin plastic straps of 1/4-1/2 inch width. Metal strapping or textile strapping could also be used as the keeper belts. The depth of recesses 24 and 30 should be from about 0.05 to 0.15 inch
The system by which the ring seal collar of this invention is attached to a header conduit is illustrated in FIGS. 3-8. First a hole is cut into the header conduit which may be duct board 41 (FIGS. 3-6) or sheet metal 43 (FIGS. 7-8). Duct board 41 typically is prepared as flat sheet stock about 1 inch in thickness of compressed insulation material and an outer covering of a moisture barrier film, e.g., aluminum. The header conduits of duct board or of sheet metal are usually rectangular hollow structures. Hole 42 (in duct board 41) or 44 (in sheet metal 43) is made slightly larger than the outside diameter of short portion 49 of conduit body 20, and short section 49 is inserted in the hole. If a sheet metal header 43 is employed, it is preferable to apply a sealant adhesive 40 to the outside of closed side 29 of ring flange 25. The use of adhesive may also be employed with a duct board header 41, but is not necessary. Ring flange 25 is then pushed against header 41 or 43. Spaced screw holes 31 are already formed in ring flange 25, through which screws 32 are inserted to pull ring flange 25 tight against the header surface. In the case of duct board it is preferred to employ large flat nuts 33 to engage screws 32. If the header is sheet metal 43, screws 32 will engage the sheet metal of header 44 without the need of nuts 33, which merely are small squares of sheet metal with a hole therein to engage the threads of screw 32.
The succeeding steps involve the attachment of an insulated conduit 34 to outlet end 22 of body 20. Generally, the insulated conduit 34 is a multi-layered hollow pipe of varying diameter sizes from 3"-20" I.D., internal hollow 35. The inside layer 36 of conduit 34 is a tubular plastic film structure bound to a helical wire structure 37. This provides a smooth inner surface and sufficient strength through the helical wire to support the entire insulated conduit in a cylindrical tubular fashion without fear of collapsing. The next layer 38 is a thick (e.g., 2 inches) fibrous insulation blanket. The outer layer 39 is a moisture barrier film of aluminum or other suitable material. A portion of the insulated conduit 38 and 39 is peeled back from inner layer 36 and 37, and inner layers 36 and 37 are slid over the outside of outlet end 22 of conduit body 20 until the forward end of layers 36 and 37 are inside ring flange 25. A keeper belt 50 is then fastened tightly around layers 36 and 37 over recess 24.
Insulation layer 38 is then rolled back in place and stuffed into the channel of ring flange 25 to provide a good insulation layer around conduit body 20. Outer layer 39 is then rolled into place over the outside of outer leg 26 of ring flange 25 and held in place by fastening keeper belt 51 over outer layer 39 and over recess 30.
While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. | Ring collar for use in connecting a side branch line to a main header air duct, the ring collar having a tubular sheet metal body with an inlet, an outlet end which is tapered for easy insertion into a tubular member, and a U-shaped channel ring around the body with the open side of the channel facing the outlet end of the body; and a process for connecting the ring collar to the main header. | 8 |
TECHNICAL FIELD OF THE INVENTION
[0001] The invention relates to a method for utilizing specialized soft key menus with different applications included in a mobile terminal. The invention also relates to a menu display controller and mobile terminal using the method. The invention relates also to a computer program product implementing the menu display controller in the mobile terminal.
BACKGROUND OF THE INVENTION
[0002] A modern mobile cellular terminal comprises many advanced software applications and distinct accessories. Some examples of these accessories are for example a digital camera, camcorder and MP3 player. The applications and accessories, which are often called plug-ins, included in the mobile terminal can have a user definable shortcut as a default setting.
[0003] All these plug-ins must be operable in the one and same cellular terminal. In the prior art a certain kind of default soft key arrangement is utilized with all these plug-ins. The user can open with one soft key a menu including selectable items. The user moves inside the menu by a browser key. The user selects one item from the menu by another soft key often named “Select”. After the made selection a new menu opens including new selectable items. Then the user once again selects one item from the menu by pressing “Select” soft key.
[0004] However, the functionality can differ a lot from one plug-in to another plug-in. This also affects to the usability of a certain plug-in when only a prior art soft default menu arrangement is at hand, which must be suitable for several plug-ins.
[0005] FIG. 1 a shows one exemplary terminal device 10 according to the prior art. It is shown in so called Normal Idle mode. The terminal device 10 in FIG. 1 a comprises a display unit 11 , a numerical/alphabetical keyboard 12 , a four-way key 121 (or advantageously a five-way key) and two programmable keys 131 and 132 , i.e. soft keys. The soft keys 131 and 132 have been arranged to perform an operation, which is shown on the display 11 beside the soft key. In the example of FIG. 1 a the soft key 132 executes a selection function, reference 112 , and the soft key 131 cancels a previous action, reference 111 . As an example on the display 11 is also shown an envelope 120 indicating that a message has been arrived and it is unread.
[0006] FIG. 1 b shows the terminal device 10 of FIG. 1 a when making browsing according to the prior art. In this example on the right side of the display 11 can be seen a primary list 113 of selectable items. One item, Calendar, is now selected and this is highlighted by an oblong 114 . A user can move inside the primary list 113 from one item to another item by utilizing the four-way key 121 . The user selects one item by pressing “Select” soft key 132 .
[0007] In the example of the FIG. 1 a the keys 12 , 121 , 131 and 132 have been implemented as separate physical keys by way of example. It is obvious to a person skilled in the art that they can also be implemented with the principle of a touchscreen display, in which case the limit between the actual display part 11 and the part that contains keys 12 , 121 , 131 and 132 is a question of definition.
[0008] The terminal 10 can also be in so called Active Idle mode. This means that applications, which are implemented in the terminal 10 , can give a distinct visual signal when the application needs the attention of the user. If the user does not react any way the signal slowly disappears or limits its size after a while. For example the envelope can fill the whole display 11 first for some seconds. If the user does not react in any way, it shrinks after a while to a small envelope 120 .
SUMMARY OF THE INVENTION
[0009] The object of the present invention is to provide a method, menu display controller, mobile terminal and computer program product for aiding a user of a mobile terminal to select and execute a function connected to an application or accessory from a menu shown on a display of the mobile terminal faster and easier than it is possible in the prior art.
[0010] The objects of the present invention are fulfilled by providing a fast method for executing a function from a menu on a display of a mobile terminal and computer program product for implementing the method, the method comprising the steps of:
[0011] providing a primary menu and a secondary menu on the display;
[0012] moving between items of the primary menu;
[0013] changing the secondary menu to show items connected to the item selected in the primary menu;
[0014] moving inside the secondary menu; and
[0015] executing a function connected to the item selected in the secondary menu.
[0016] Also the objects of the present invention are fulfilled by providing a menu display controller and mobile terminal utilizing the display controller comprising:
[0017] a means for showing a primary menu and secondary menu on a display of the mobile terminal;
[0018] a means for moving between items of the primary menu;
[0019] a means for changing the secondary menu to show items connected to the item selected in the primary menu;
[0020] a means for moving inside the secondary menu; and
[0021] a means for executing a function connected to the item selected in the secondary menu.
[0022] According to the present invention a mobile terminal includes a means which allows utilizing two separate menus at the same time on a display of the mobile terminal. The two menus according to the invention are shown on a display of the mobile terminal when browsing between possible applications and accessories, which are included in the mobile terminal. The main menu according to the invention can be called as a primary menu. The user of the mobile terminal can move inside the primary menu by utilizing a first browser key. When the user moves inside the primary menu from one item to another that changes items of the secondary menu also shown on the display of the mobile terminal. The secondary menu includes the most frequently utilized functional alternatives of the item, which is currently selected from the primary menu. The user of the mobile terminal can also move inside the secondary menu advantageously by utilizing a second browser key. When a cursor of the secondary menu is on an item which the user wants to execute, the user advantageously presses an execute key.
[0023] In one advantageous embodiment of the invention the secondary menu disappears after a while if the user does not react to the changed secondary menu.
[0024] In another advantageous embodiment of the invention the secondary menu returns to a default which discloses only one item “Select” if the user does not react to the changed secondary menu.
[0025] Further scope of applicability of the present invention will become apparent from the detailed description given hereafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The present invention will become more fully understood from the detailed description given herein below and accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention and wherein
[0027] FIG. 1 a shows a schematical representation of a mobile terminal of a prior art in Normal Idle mode;
[0028] FIG. 1 b shows a schematical representation of a mobile terminal of a prior art in Normal Idle mode during a menu browsing operation;
[0029] FIG. 2 a shows an example of a display of a mobile terminal utilizing the present invention during the browsing;
[0030] FIG. 2 b shows an example where on a display of a mobile terminal utilizing the present invention the secondary menu has returned to a default;
[0031] FIG. 3 shows as an exemplary flow chart including main stages of the method according to the invention; and
[0032] FIG. 4 shows the main parts of the terminal device according to the invention by way of example.
DETAILED DESCRIPTION
[0033] FIGS. 1 a and 1 b were discussed in conjunction with the description of the prior art.
[0034] FIGS. 2 a and 2 b illustrate an example how the present invention can be applied in a mobile terminal 20 . The main functional elements of the mobile terminal 20 were already discussed with FIGS. 1 a and 1 b.
[0035] In FIG. 2 a the display 11 of the mobile terminal 20 according to the invention comprises two separate menus. They are a primary menu 213 and a secondary menu 212 a . The primary menu 213 comprises advantageously all user applications which are implemented in the mobile terminal 20 . If the list is too long to fit in the display 11 in one go, it can advantageously be scrolled up or down when the cursor is in the upper most or lower most item of the primary menu 213 . The secondary menu 212 a comprises advantageously at least partly different items for every item included in the primary menu 213 .
[0036] The user can move inside the primary menu 213 by a browser key. In the example of FIG. 2 a the user can advantageously utilize up and down choices of a four-way key 121 when moving inside the primary menu 213 . With the four-way key 121 the user has in the example of FIG. 2 a moved a cursor oblong 214 on “Calendar” application.
[0037] The cursor movement above “Calendar” has caused a secondary menu 212 a to be opened on the display 11 . In this context the secondary menu 212 a comprises four possible time alternatives which can be opened because the content of the secondary menu 212 a is tied with the item “Calendar” in the primary menu 213 .
[0038] The user can move a secondary cursor in the secondary menu 212 a by the secondary browser key. Advantageously left and right choices of the four-way key 121 can be utilized to move the secondary cursor 215 . In the example of FIG. 2 a the user has moved a secondary cursor, oblong 215 , above an item “Today”.
[0039] If the user now presses an execution key, a calendar of today opens on the display 11 . If the mobile terminal 20 comprises a five-way, the opening of the alternative “Today” can advantageously be done by pressing the middle of the five-way key.
[0040] It is obvious to a man skilled in the art that any other keys included in the mobile terminal 20 can be utilized to move the primary cursor 214 , secondary cursor 215 or execution key instead of the depicted four-way key (five-way key). Also it is obvious to use other cursor types than the depicted oblong of FIGS. 2 a and 2 b
[0041] FIG. 2 b depicts a situation where the user of the mobile terminal 20 has not been reacted to the opened secondary menu 212 a . In the method according to the invention the secondary menu 212 a of FIG. 2 a shrink to a soft key “Select”, reference 212 b , after a predetermined time. The time after which this happens is advantageously user definable.
[0042] If the user after a while presses key 132 , the secondary menu 212 a advantageously opens again. There are two advantageous embodiments which differ from each other in a content of the secondary menu. In the first advantageous embodiment the content is the same, which was earlier opened up because of the movement of the primary cursor 214 .
[0043] In a second advantageous embodiment the secondary menu comprises more choices than the secondary menu 212 a which was automatically opened. This feature allows to the user a flexible way to work with an expanded secondary menu. If the most frequently items are enough the user can activate the function right away from the automatically opened secondary menu 212 a . If it lacks an item needed by the user, the user only waits some seconds and by selecting the secondary menu again the user comes on line the whole repertoire of choices.
[0044] The idea of the present invention is to offer to the user for a while those options immediately, which in the prior art are achieved by using “Select” soft key. This makes the selection faster and easier for the user of the mobile terminal.
[0045] The main steps of the method according to the invention are shown as an exemplary flow chart in FIG. 3 . Also the features explained with FIGS. 2 a and 2 b are used to aid in the description.
[0046] The process starts in step 31 where the user activates in a mobile terminal 20 a selection or execution function. This opens up two menus according to the invention, i.e. a primary menu 213 and secondary menu 212 a.
[0047] The user of the mobile terminal can move inside the primary menu 213 by a browsing key or keys 121 . This is depicted as step 32 in the flow chart. When a movement of the cursor 214 takes place from one item of the primary menu 213 to another, due to that a secondary menu 212 a opens up on the display 11 of the mobile terminal 20 in step 33 . Advantageously the secondary menu 212 a according to the invention comprises those alternatives for action, which are most frequently used.
[0048] The secondary menu 212 a stays on the display for a predetermined duration. After that time in step 34 a comparison is made where it is checked if the user has selected or not an item from the secondary menu 212 a . If the answer to the comparison 34 is “Yes”, the selected item is executed in step 36 . After that the process ends in step 37 .
[0049] However, if the comparison gives a negative answer “No”, i.e. the user has not reacted to the secondary menu 212 a , in the step 35 the secondary menu 212 a shrinks to a default setting 212 b and the process can continue once again from step 32 .
[0050] FIG. 4 shows, by way of example, the functional main parts of a terminal device 40 of a cellular network capable of utilizing the selection and execution method according to the invention. The terminal device 40 can be, for example, a prior art GSM, GPRS or UMTS terminal device.
[0051] The terminal device 40 uses an antenna 41 in the transmission and reception of signals with the serving cellular network. The receiver means RX of the terminal device 40 are shown by reference 42 . The receiver RX comprises prior art means for all messages or signals to be received.
[0052] Reference 43 denotes the means of which the transmitter TX of the terminal device 40 is composed. All the signal processing measures required when operating with a cellular network are performed on the signal to be transmitted by the transmitter means 43 .
[0053] When operating in a prior art cellular network, such as the GSM network, the terminal device 40 also requires a SIM card (not shown in FIG. 4 ) in order to function.
[0054] In the terminal device 40 , an essential part with regard to the utilization of the invention is the central processing unit 44 that controls operations of the transmitter and receiver. It controls also the memory 45 , in which the software application required in the implementation of the method according to the invention can advantageously be saved.
[0055] The terminal device 40 also comprises a user interface 46 . It comprises at least a display and keyboard functions as shown in FIGS. 2 a and 2 b (not shown in FIG. 4 ). In the method according to the invention the central processing unit 44 controls how the primary and secondary menus are shown on the display of the mobile terminal and how the commands or functions connected the items of these menus are executed. This control function can be called as a menu display controller.
[0056] 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 within the scope of the following claims. | The invention relates to a method for utilizing specialized primary and secondary menus for different applications included in a mobile terminal. The invention also relates to a menu display controller and mobile terminal using the method. In the method a cursor movement between items of the primary menu causes a new secondary menu to appear on the display. The user can also move inside the secondary menu and execute directly from the secondary menu a function included in the secondary menu. | 7 |
The present invention is directed to a process for preparing a fibrillated article, the process comprising the steps of fibrillating an oriented, high melt strength polypropylene foam. The foam may be prepared by extruding a foamable mixture comprising a high melt-strength polypropylene and a blowing agent, and orienting in at least one direction.
SUMMARY OF THE INVENTION
The present invention is further directed to a process for producing a fibrillated article, prepared from an oriented foamed polymer. The fibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as a diffuse reflector for use in optical applications such as computer displays and as reinforcement fibers for polymers or cast building materials such as concrete.
In another aspect, the present invention provides a process for preparing a fibrillated article, using a foamable mixture comprising a major amount of a high melt-strength polypropylene and a minor amount of a second polymer component comprising a semicrystalline or amorphous thermoplastic polymer. Polymer mixtures comprising a high melt-strength polypropylene and two or more added polymers are also within the scope of the invention.
In another aspect, the present invention provides fibrillated articles prepared by the process of the invention. The present invention also provides fibrillated articles that comprise an oriented, high melt strength polypropylene foam having a fibrillated surface. The fibrillated surface may be fibrous or schistose in nature. The fibrillated article are useful as tape backings, filters, thermal and acoustical insulation and as reinforcement fibers for polymers or cast building materials such as concrete.
In another aspect the present invention provides polymeric microfibers prepared by the process of the invention. The microfibers are generally between about 0.5 and 10 μm in cross section, have relatively uniform fiber diameters, are low cost and may be prepared from readily available starting materials. The process of the invention can produce many different profiles of fibrillated article by fibrillation of the corresponding foam profile, such as sheet, blocks, tubes, cylinders, or rods.
As used in this invention:
“Alpha-transition temperature”,Tαc, is the temperature at which crystallite subunits of a polymer are capable of being moved within the larger lamellar crystal unit. Above this temperature lamellar slip can occur, and extended chain crystals form, with the effect that the degree of crystallinity is increased as amorphous regions of the polymer are drawn into the lamellar crystal structure.
“small-cell foam” means a foam having cell sizes of less than 100 micrometers (μm), preferably 5 to 50 μm;
“closed-cell foam” means a foam that contains substantially no connected cell pathways that extend from one outer surface through the material to another outer surface;
“operating temperature” means the temperature that must be achieved in the extrusion process to melt all of the polymeric materials in the melt mix;
“exit temperature” and “exit pressure” mean the temperature and pressure of the extrudate in the final zone or zones of the extruder and preferably in the die;
“melt solution ” or “melt mixture” or “melt mix” means a melt-blended mixture of polymeric material(s), any desired additives, and blowing agent(s) wherein the mixture is sufficiently fluid to be processed through an extruder;
“neat polymer” means a polymer that contains small amounts of typical heat-stabilizing additives, but contains no fillers, pigments or other colorants, blowing agents, slip agents, anti-blocking agents, lubricants, plasticizers, processing aids, antistatic agents, ultraviolet-light stabilizing agents, or other property modifiers;
“foam density” means the weight of a given volume of foam;
“density reduction” refers to a way of measuring the void volume of a foam based on the following formula: ρ R = [ 1 - ρ f ρ o ] × 100 %
where ρ R is the density reduction, ρ f is the foam density, and ρ o is the density of the original material;
“polydispersity” means the weight average cell diameter divided by the number average cell diameter for a particular foam sample; it is a means of measuring the uniformity of cell sizes in the sample;
“uniform” means that the cell size distribution has a polydispersity of 1.0 to 2.0;
“spherical” means generally rounded; it may include spherical, oval, or circular structure;
“fibrillose” or “fibrous” means having elongated filament-like or thread-like structures;
“schistose” means having parallel plate-like ribbons or flakes;
“polymer matrix” means the polymeric, or “non-cell,” areas of a foam;
“α-olefin” means an olefin having three or more carbon atoms and having a —CH═CH 2 group.
BRIEF DESCRIPTION OF THE FIGURES
FIGS. 1 and 2 are schematics of processes for preparing the foams used in the present invention.
FIG. 3 is a digital image of a scanning electron micrograph (SEM) of a side elevation of the foam of Example 1.
FIG. 4 is a digital image of a SEM of a side elevation of the fibrillated foam of Example 1.
FIG. 5 is a digital image of a SEM of the fibers of Example 2.
FIG. 6 is a digital image of a SEM of the fibrillated foam of Example 3.
DETAILED DESCRIPTION
The high melt strength polypropylene useful in the present invention includes homo- and copolymers containing 50 weight percent or more propylene monomer units, preferably at least 70 weight percent, and has a melt strength in the range of 25 to 60 cN at 190° C. Melt strength may be conveniently measured using an extensional rheometer by extruding the polymer through a 2.1 mm diameter capillary having a length of 41.9 mm at 190° C. and at a rate of 0.030 cc/sec; the strand is then stretched at a constant rate while measuring the force. Preferably the melt strength of the polypropylene is in the range of 30 to 55 cN, as described in WO 99/61520.
The melt strength of linear or straight chain polymers, such as conventional isotactic polypropylene, decreases rapidly with temperature. In contrast, the melt strength of highly branched polypropylenes does not decrease rapidly with temperature. It is generally believed that the differences in melt strengths and extensional viscosity are attributable to the presence of long chain branching. Useful polypropylene resins are those that are branched or crosslinked. Such high melt strength polypropylenes may be prepared by methods generally known in the art. Reference may be made to U.S. Pat. No. 4,916,198 (Scheve et al) which describes a high melt strength polypropylene having a chain-hardening elongational viscosity prepared by irradiation of linear propylene in a controlled oxygen environment. Other useful methods include those in which compounds are added to the molten polypropylene to introduce branching and/or crosslinking such as those methods described in U.S. Pat. No. 4,714,716 (Park), WO 99/36466 (Moad, et al.) and WO 00/00520 (Borve et al.). High melt strength polypropylene may also be prepared by irradiation of the resin as described in U.S. Pat. No. 5,605,936 (Denicola et al.). Still other useful methods include forming a bipolar molecular weight distribution as described in J. I. Raukola, A New Technology To Manufacture Polypropylene Foam Sheet And Biaxially Oriented Foam Film, VTT Publications 361, Technical Research Center of Finland, 1998 and in U.S. Pat. No. 4,940,736 (Alteepping and Nebe), incorporated herein by reference.
The foamable polypropylene may consist of propylene homopolymers or may comprise a copolymer having 50 wt % or more propylene monomer content. Further, the foamable polypropylene may comprise a mixture or blend of propylene homopolymers or copolymers with a homo- or copolymer other than propylene homo- or copolymers.
Particularly useful propylene copolymers are those of propylene and one or more non-propylenic monomers. Propylene copolymers include random, block, and graft copolymers of propylene and olefin monomers selected from the group consisting of C3-C8 α-olefins and C4-C10 dienes. Propylene copolymers may also include terpolymers of propylene and α-olefins selected from the group consisting of C3-C8 α-olefins, wherein the α-olefin content of such terpolymers is preferably less than 45 wt %. The C3-C8 α-olefins include 1-butene, isobutylene, 1-pentene, 3-methyl-1 -butene, 1-hexene, 3,4-dimethyl1-butene, 1-heptene, 3-methyl-1-hexene, and the like. Examples of C4-C10 dienes include 1,3-butadiene, 1,4-pentadiene, isoprene, 1,5-hexadiene, 2,3-dimethyl hexadiene and the like.
Other polymers that may be added to the high melt strength polypropylene in the foamable composition include high, medium, low and linear low density polyethylene, fluoropolymers, poly(1-butene), ethylene/acrylic acid copolymer, ethylene/vinyl acetate copolymer, ethylene/propylene copolymer, styrene/butadiene copolymer, ethylene/styrene copolymer, ethylene/ethyl acrylate copolymer, ionomers and thermoplastic elastomers such as styrene/ethylene/butylene/styrene (SEBS), and ethylene/propylene/diene copolymer (EPDM).
The present invention provides a process for preparing a fibrillated article comprising the step of fibrillating an oriented, high melt strength polypropylene foam wherein said oriented foam is prepared by the steps of extruding a mixture comprising a high melt-strength polypropylene and a blowing agent to produce a foam, and orienting the extruded foam in at least one direction. Preferably the method comprises mixing at least one high melt strength polypropylene and at least one blowing agent in an apparatus having an exit shaping orifice at a temperature and pressure sufficient to form a melt mixture wherein the blowing agent is uniformly distributed throughout the polypropylene; reducing the temperature of the melt mixture at the exit of the apparatus to an exit temperature that no more than 30° C. above the melt temperature of the neat polypropylene while maintaining the melt mixture at a pressure sufficient to prevent foaming; passing the mixture through said exit shaping orifice and exposing the mixture to atmospheric pressure, whereby the blowing agent expands causing cell formation resulting in foam formation; orienting the foam; and fibrillating the foam.
An extrusion process using a single-screw, twin-screw or tandem extrusion system may prepare the foams useful in the present invention. This process involves mixing one or more high melt strength propylene polymers (and any optional polymers to form a propylene polymer blend) with a blowing agent, e.g., a physical or chemical blowing agent, and heating to form a melt mixture. The temperature and pressure conditions in the extrusion system are preferably sufficient to maintain the polymeric material and blowing agent as a homogeneous solution or dispersion. Preferably, the polymeric materials are foamed at no more than 30° C. above the melting temperature of the neat polypropylene thereby producing desirable properties such as uniform and/or small cell sizes.
When a physical blowing agent, such as CO 2 is used, the neat polymer is initially maintained above the melting temperature. The physical blowing agent is injected (or otherwise mixed) with the molten polymer and the melt mixture is cooled in the extruder to an exit temperature that is less than 30° C. above the melting temp of the neat polymer (T≦T m +30° C.) while the pressure is maintained at or above 2000 psi (13.8 MPa). Under these conditions the melt mixture remains a single phase. As the melt mixture passes through the exit/shaping die the melt rapidly foams and expands, generating foams with small, uniform cell sizes. It has been found that, by adding a physical blowing agent, the polypropylene may be processed and foamed at temperatures considerably lower than otherwise might be required. The blowing agent plasticizes, i.e., lowers the T m of, the polymeric material. The lower temperature can allow the foam to cool and stabilize soon after it exits the die, thereby making it easier to arrest cell growth and coalescence while the cells are smaller and more uniform.
When a chemical blowing agent is used, the blowing agent is added to the neat polymer, mixed, heated to a temperature above the T m of the polypropylene to ensure intimate mixing and further heated to the activation temperature of the chemical blowing agent, resulting in decomposition of the blowing agent. The temperature and pressure of the system are controlled to maintain substantially a single phase. The gas formed on activation is substantially dissolved or dispersed in the melt mixture. The resulting single phase mixture is cooled to an exit temperature no more than 30° C. above the melting temperature of the neat polymer, while the pressure is maintained at or above 2000 psi, (13.8 Mpa) by passing the mixture through a cooling zone(s) in the extruder prior to the exit/shaping die. Generally the chemical blowing agent is dry blended with the neat polymer prior to introduction to the extruder, such as in a mixing hopper.
With either a chemical or physical blowing agent, as the melt mixture exits the extruder through a shaping die, it is exposed to the much lower atmospheric pressure causing the blowing agent (or its decomposition products) to expand. This causes cell formation resulting in foaming of the melt mixture. When the exit temperature is no more than 30° C. above the T m of the neat polypropylene, the extensional viscosity of the polymer increases as the blowing agent comes out of the solution and the polypropylene rapidly crystallizes. These factors arrest the growth and coalescense of the foam cells within seconds or, most typically, a fraction of a second. Preferably, under these conditions, the formation of small and uniform cells in the polymeric material occurs. When exit temperatures are in excess of 30° C. above the T m of the neat polymer, cooling of the polymeric material may take longer, resulting in non-uniform, unarrested cell growth. In addition to the increase in T m , adiabatic cooling of the foam may occur as the blowing agent expands.
Either a physical or chemical blowing agent may plasticize, i.e., lower the T m and T g of, the polymeric material. With the addition of a blowing agent, the melt mixture may be processed and foamed at temperatures considerably lower than otherwise might be required, and in some cases may be processed below the melting temperature of the neat polypropylene. The lower temperature can allow the foam to cool and stabilize (i. e., reach a point of sufficient solidification to arrest further cell growth) and produce smaller and more uniform cell sizes.
Physical blowing agents useful in the present invention may be any material that is a vapor at the temperature and pressure at which the foam exits the die. The physical blowing agent may be introduced, i.e., injected, into the polymeric material as a gas, a supercritical fluid, or liquid, preferably as a supercritical fluid or liquid, most preferably as a liquid. The physical blowing agents used will depend on the properties sought in the resulting foam articles. Other factors considered in choosing a blowing agent are its toxicity, vapor pressure profile, ease of handling, and solubility with regard to the polymeric materials used. Flammable blowing agents such as pentane, butane and other organic materials may be used, but non-flammable, non-toxic, non-ozone depleting blowing agents such as hydrofluorocarbons (HFC), hydrochlorofluorocarbons (HCFC), and fully- or partially fluorinated ethers are preferred because they are easier to use, e.g., fewer environmental and safety concerns. Suitable physical blowing agents include, e.g., carbon dioxide, nitrogen, water, SF 6 , nitrous oxide, argon, helium, noble gases such as xenon, air (nitrogen and oxygen blend), and blends of these materials.
Chemical blowing agents are added to the polymer at a temperature below that of the decomposition temperature of the blowing agent, and are typically added to the polymer feed at room temperature prior to introduction to the extruder. The blowing agent is then mixed to distribute it throughout the polymer in undecomposed form, above the melt temperature of the polymer, but below the activation temperature of the chemical blowing agent. Once dispersed, the chemical blowing agent may be activated by heating the mixture to a temperature above the decomposition temperature of the agent. Decomposition of the blowing agent liberates gases, such as N 2 , CO, CO 2 and/or H 2 O, yet cell formation is restrained by the temperature and pressure of the system. Useful chemical blowing agents typically decompose at a temperature of 140° C. or above. As previously described the mixture is cooled to a temperature at or below T m +30° C. prior to exiting the die.
Examples of such materials include synthetic azo-, carbonate-, and hydrazide-based molecules, including azodicarbonamide, azodiisobutyronitrile, benzenesulfonylhydrazide, 4,4-oxybenzene sulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, barium azodicarboxylate, N,N′-dimethyl-N,N′-dinitrosoterephthalamide and trihydrazino triazine. Specific examples of these materials are Celogen OT (4,4′ oxybis (benzenesulfonylhydrazide), Hydrocerol BIF (preparations of carbonate compounds and polycarbonic acids), Celogen AZ (azodicarboxamide) and Celogen RA (p-toluenesulfonyl semicarbazide).
The amount of blowing agent incorporated into the foamable polymer mixture is chosen to yield a foam having a void content in excess of 10%, more preferably in excess of 20%, as measured by density reduction; i.e., [1−the ratio of the density of the foam to that of the neat polymer]×100. Generally, greater foam void content enhances the subsequent fibrillation and subsequently, the greater the yield of the fibrillated surface.
FIG. 1 illustrates a tandem extrusion apparatus 10 that may be used to make the foams of the present invention, and is a preferred process for use with a physical blowing agent. To form a melt mixture, polymeric material is initially fed from hopper 12 into a first extruder 14 that melts and conveys the polymeric material. The polymeric material may be added to extruder 14 in any convenient form. Additives are typically added with the polymer material but may be added further downstream. The blowing agent, typically in a liquid or supercritical form, is injected near the exit of the first extruder. Due to the conditions in the extruder, the blowing agent is typically in a supercritical state while in the extruder.
The polymers, additives, and blowing agent are melt-mixed in first extruder 14 . The physical blowing agent is typically introduced by injection at some intermediate stage of extruder 14 by means of fluid handling equipment 16 . The purpose of the melt-mixing step is to prepare a foamable, extrudable composition in which the blowing agent and other additives, to the extent present, are distributed homogeneously throughout the molten polymeric material. Specific operating conditions are selected to achieve such homogeneous distribution based upon the properties and characteristics of the particular composition being processed. The operating and exit pressures in extruder 14 should be sufficient to prevent the blowing agent from expanding in the extruder. The operating temperature in extruder 14 should be sufficient to melt and/or soften all of the polymers in the melt mixture.
Next, the melt mixture is fed to second extruder 20 (typically a single screw extruder) by means of conduit 18 . Extruder 20 is generally operated at conditions (e.g., screw speed, screw length, pressure, and temperature) selected to achieve optimum mixing, and to keep the blowing agent in solution. Extruder 20 typically has a decreasing temperature profile wherein the temperature of the last zone or zones will bring the melt mixture to the desired exit temperature.
At the exit end of extruder 20 , the foamable, extrudable composition is metered into die 22 which has a shaping/exit orifice (e.g., an annular, rod, slit, or shaped profile die). The temperature within die 22 is preferably maintained at substantially the same temperature as the last zone of extruder 20 ; i.e., at the exit temperature. The relatively high pressure within extruder 20 and die 22 prevents cell formation and foaming of the melt mixture. Exit pressure is dependent upon die orifice size, exit temperature, blowing agent concentration, polymer flowrate, polymer viscosity, screw speed and polymer. Exit pressure is typically controlled by adjusting the die orifice size, but can also be adjusted by altering the exit temperature, blowing agent concentration, and other variables. Reducing the size of the die orifice will generally increase exit pressure. As the composition exits die 22 through the die's shaping orifice, it is exposed to ambient pressure. The pressure drop causes the blowing agent to expand, leading to cell formation. Foam 24 is typically quenched, i.e., brought to a temperature below the T m of the polypropylene, within two to five centimeters of the die exit, more typically and preferably less than two centimeters, as the foamable material exits the die and is exposed to ambient pressure.
The shape of the die exit orifice dictates the shape of foam 24 . A variety of shapes may be produced, including a continuous sheet (wherein the sheet may have a patterned profile), a tube, a rope, etc.
In general, as the blowing agent separates from the melt mixture, its plasticizing effect on the polymeric material decreases and the extensional viscosity of the polymeric material increases. The viscosity increase is much sharper at the T m than at the T g , making the choice of foaming temperatures for semicrystalline polymers much more stringent than for amorphous polymers. As the temperature of the polymeric material approaches the T m of the neat polypropylene and becomes more viscous, the cells cannot as easily expand or coalesce. As the foam material cools further, it solidifies in the general shape of the exit shaping orifice of die 22 .
FIG. 2 illustrates a single stage extrusion apparatus 40 that can be used to make the foams of the present invention, and is the preferred process for use with chemical blowing agents. A twin screw extruder 44 (as depicted) may be used to form a melt mixture of the polypropylene and blowing agent, although it will be understood that a single screw extruder may also be used. The polypropylene is introduced into zone 1 of extruder 44 by means of hopper 42 . Chemical blowing agents are typically added with the polymer but may be added further downstream. A physical blowing agent may be added using fluid handling means 46 at a location downstream from a point at which the polymer has melted.
When a physical blowing agent is used, extruder 44 may be operated with a generally decreasing temperature profile. If a chemical blowing agent is used, an intermediate zone is generally maintained at an elevated temperature sufficient to initiate the chemical blowing agent, followed by subsequent cooler zones. The temperature of the initial zone(s) of the extruder must be sufficient to melt the polypropylene and provide a homogenous melt mixture with the blowing agent. The final zone or zones of the extruder are set to achieve the desired extrudate exit temperature.
Using a single stage extrusion process, as compared to using a tandem process, to produce a homogeneous foamable mixture requires mixing and transitioning from an operating temperature and pressure to an exit temperature and pressure over a shorter distance. To achieve a suitable melt mixture, approximately the first half of the extruder screw may have mixing and conveying elements which knead the polymer and move it through the extruder. The second half of the screw may have distributive mixing elements to mix the polymer material and blowing agent into a homogeneous mixture while cooling.
As with the tandem process, the operating and exit pressures (and temperatures) should be sufficient to prevent the blowing agent from causing cell formation in the extruder. The operating temperature is preferably sufficient to melt the polymer materials, while the last zone or zones of the extruder are preferably at a temperature that will bring the extrudate to the exit temperature.
At the exit end of the extruder, the foamable, extrudable composition is metered into die 48 having a shaping exit orifice. The foam is generated in the same manner as with the tandem system.
The blowing agent concentrations, exit pressure, and exit temperature can have a significant effect on the properties of the resulting foams including foam density, cell size, and distribution of cell sizes. In general, the lower the exit temperature, the more uniform, and smaller, the cell sizes of the foamed material. This is because at lower exit temperatures, the extensional viscosity is higher, yielding slower cell growth. Extruding the material at lower than normal extrusion temperatures, i.e. no more than 30° C. above the T m of the neat polymeric material, produces foams with small, uniform cell sizes.
In general, as the melt mixture exits the die, it is preferable to have a large pressure drop over a short distance. Keeping the solution at a relatively high pressure until it exits the die helps to produce uniform cell sizes. Maintaining a large pressure drop between the exit pressure and ambient pressure can also contribute to the quick foaming of a melt mixture. The lower limit for forming a foam with uniform cells will depend on the critical pressure of the blowing agent being used. In general, for the high melt-strength polypropylene useful in the invention, the lower exit pressure limit for forming acceptably uniform cells is approximately 7 MPa (1000 psi), preferably 10 MPa (1500 psi), more preferably 14 MPa (2000 psi). The smallest cell sizes may be produced at low exit temperatures and high blowing agent concentrations. However at any given temperature and pressure, there is a blowing agent concentration at and above which polydispersity will increase because the polymer becomes supersaturated with blowing agent and a two phase system is formed.
The optimum exit temperature, exit pressure, and blowing agent concentration for a particular melt mixture will depend on a number of factors such as the type and amount of polymer(s) used; the physical properties of the polymers, including viscosity; the mutual solubility of the polymer(s) and the blowing agent; the type and amount of additives used; the thickness of the foam to be produced; the desired density and cell size; whether the foam will be coextruded with another foam or an unfoamed material; and the die gap and die orifice design.
The present invention provides foams having average cell sizes less than 100 micrometers, and advantageously may provide foams having average cell sizes less than 50 micrometers. Additionally the foams produced have a closed cell content of 70 percent or greater. As result of extrusion, the cells will be elongated in the machine direction.
In order to optimize the physical properties of the foam and fibrillated article, the polymer chains need to be oriented along at least one major axis (uniaxial), and may further be oriented along two major axes (biaxial). The degree of molecular orientation is generally defined by the draw ratio, that is, the ratio of the final length to the original length.
Upon orientation, greater crystallinity is imparted to the polypropylene component of the foam and the dimensions of the foam cells change. Typical cells have major directions X and Y, proportional to the degree of orientation in the machine and transverse direction respectively. A minor direction Z, normal to the plane of the foam, remains substantially the same as (or may be moderately less than) the cross-sectional dimension of the cell prior to orientation.
The conditions for orientation are chosen such that the integrity of the foam is maintained. Thus, when stretching in the machine and/or transverse directions, the orientation temperature is chosen such that substantial tearing or fragmentation of the continuous phase is avoided and foam integrity is maintained. The foam is particularly vulnerable to tearing, cell rupture or even catastrophic failure if the orientation temperature is too low or the orientation ratio(s) is/are excessively high. Generally the foam is oriented at a temperature between the glass transition temperature and the melting temperature of the neat polypropylene. Preferably, the orientation temperature is above the alpha transition temperature of the neat polymer. Such temperature conditions permit optimum orientation in the X and Y directions without loss of foam integrity, consequently maximizing the ease with which the surface(s) may be fibrillated.
Unexpectedly, it has been found that orienting reduces the foam density, thus enabling the production of lower density foams than are achievable using blowing agents alone. Up to a 60% reduction in density has been observed. Further, fibrillation of oriented foams requires less fluid pressure (i.e. less energy) than does fibrillation of unfoamed films that have a higher degree of orientation. The instant invention provides additional benefits to the ultimate fibrillated article such as lower operating and equipment costs, better insulation properties, better tear properties and ease of manufacturing.
After orientation the cells are relatively planar in shape and have distinct boundaries. Cells are generally coplanar with the major surfaces of the foam, with major axes in the machine (X) and transverse (Y) directions (directions of orientation). The sizes of the cells are substantially uniform and dependent on concentration of blowing agent, extrusion conditions and degree of orientation. The percentage of closed cells does not change significantly after orientation when using high melt strength polypropylene. In contrast, orientation of conventional polypropylene foam results in cell collapse and tearing of the foam, reducing the percentage of closed cells. Cell size, distribution and amount in the foam matrix may be determined by techniques such as scanning electron microscopy.
In the orienting step, the foam is stretched in the machine direction and may be simultaneously or sequentially stretched in the transverse direction. When first stretched in the machine direction, the individual fibrils of the spherulites of the polypropylene are drawn substantially parallel to the machine direction (direction of orientation) of the film and in the plane of the film. The oriented fibrils can be visualized as having a rope-like appearance. Subsequent or further orientation of the film in the transverse direction results in reorientation of the fibrils, again in the plane of the film, with varying populations along the X,Y and intermediate axes, depending on the degree of orientation in the machine and transverse directions.
The stretching conditions are chosen to increase the crystallinity of the polymer matrix and the void volume of the foam. It has been found that an oriented foam is readily fibrillated, even with a relatively low void content when compared to oriented, unfoamed films, and is readily fibrillated at a lower total draw ratio compared to unfoamed film. In other words, the foams need not be as highly oriented as films to achieve subsequent fibrillation. As used herein “total draw ratio” is the product of the draw ratios in the machine and transverse directions, i.e=MD×TD.
Additionally, the high melt strength polypropylene allows the preparation of foams with smaller cell sizes, and a larger density decrease on orientation (to produce a lower density foam) than conventional polypropylene. Lower density foams may be more easily fibrillated than higher density foams. The high melt strength polypropylene also allows higher draw ratios to produce fibrillated articles and fibers having higher tensile strength than can be achieved with conventional polypropylene.
The foam may be biaxially oriented by stretching in mutually perpendicular directions at a temperature above the alpha transition temperature and below the melting temperature of the polypropylene. Generally, the foam is stretched in one direction first and then in a second direction perpendicular to the first. However, stretching may be effected in both directions simultaneously if desired. If biaxial orientation is desired, it is preferable to simultaneously orient the foam, rather than sequentially orient the foam along the two major axes. It has been found that simultaneous biaxial orientation provides improved physical properties such as tensile strength as compared to sequential biaxial orientation.
In a typical sequential orientation process, the foam is stretched first in the direction of extrusion over a set of rotating rollers then stretched in the transverse direction by means of a tenter apparatus. Alternatively, foams may be stretched in both the machine and transverse directions in a tenter apparatus. Foams may be stretched in one or both directions 3 to 50 times total draw ratio (MD×TD). Greater orientation is achievable using foams of small cell size; foams having cell size of greater than 100 micrometers are not readily oriented more than 20 times, while foams having a cell size of 50 micrometers or less may be stretched up to 50 times total draw ratio.
The temperature of the polymer foam during the first orientation (or stretching) step affects foam properties. Generally, the first orientation step is in the machine direction. Orientation temperature may be controlled by the temperature of heated rolls or by the addition of radiant energy, e.g., by infrared lamps, as is known in the art. A combination of temperature control methods may be utilized. Too low an orientation temperature may result in tearing the foam and rupturing the cells. Orientation is generally conducted at temperatures between the glass transition temperature and the melting temperature of the neat polypropylene, i.e. at about 110-170° C., preferably 110-140° C. A second orientation, in a direction perpendicular to the first orientation may be desired. The temperature the foam during the second orientation step is generally similar to or higher than the temperature of the first orientation.
After the foam has been stretched it may be further processed. For example, the foam may be annealed or heat-set by subjecting the foam to a temperature sufficient to further crystallize the polypropylene while restraining the foam against retraction in both directions of stretching.
The final thickness of the foam will be determined in part by the extrudate thickness, the degree of orientation, and any additional processing. For most uses, the final thickness of the foam prior to fibrillation will be 2 to 100 mils (0.05 to 2.5 mm), preferably 10 to 60 mils (0.25 to 1.5 mm).
The oriented foam may be fibrillated by imparting sufficient fluid energy to the surface to release the fibers (or fibrous flakes) from the polymer matrix. Optionally, prior to fibrillation, the foam may be subjected to a mechanical fibrillation step by conventional means to produce macroscopic fibers from the film. The conventional means of mechanical fibrillation uses a rotating drum or roller having cutting elements such as needles or teeth in contact with the moving film. The teeth may fully or partially penetrate the surface of the film to impart a fibrillated surface thereto. Other similar macrofibrillating treatments are known and include such mechanical actions as twisting, brushing (as with a porcupine roller), rubbing, for example with leather pads, and flexing. The fibers obtained by such conventional fibrillation processes are macroscopic in size, generally several hundreds of microns in cross section. Such macroscopic fibers are useful in a myriad of products such as particulate filters, as oil absorbing media, and as electrets.
The oriented foam may be fibrillated by imparting sufficient fluid energy thereto to produce a fibrillated surface, for example, by contacting a portion of at least one surface of the film with a high-pressure fluid. In the present fibrillation process, relatively greater amounts of energy are imparted to the film surface to release microfibers, relative to that of a conventional mechanical fibrillation process. Surprisingly, it has been found that less energy is required to fibrillate oriented foams than is required for non-foamed polymer films. Thus the present invention provides oriented foams having a fibrous surface (for uniaxially oriented foams) or a schistose surface (for biaxially oriented foams).
One method of fibrillating the surface of the foam is by means of fluid jets. In this process one or more jets of a fine fluid stream impact the surface of the foam, which may be supported by a screen or moving belt, thereby releasing fibers from the uniaxially oriented foam, or fibrous flakes from the biaxially oriented foam. One or both surfaces of the foam may be fibrillated. The degree of fibrillation is dependent on exposure time of the foam to the fluid jet, pressure of the fluid jet, cross-sectional area of the fluid jet, fluid contact angle, polymer properties, including composition of the high melt strength polymer, void content of the foam and, to a lesser extent, fluid temperature. Different types and sizes of screens can be used to support the foam.
Any type of liquid or gaseous fluid may be used. Liquid fluids may include water or organic solvents such as ethanol or methanol. Suitable gases such as nitrogen, air or carbon dioxide may be used, as well as mixtures of liquids and gases. Any such fluid is preferably non-swelling (i.e., is not absorbed by the polymer matrix), which would reduce the orientation and degree of crystallinity of the fibers or flakes. Preferably the fluid is water. The fluid temperature may be elevated, although suitable results may be obtained using ambient temperature fluids. For some polymer systems it may be advantageous to use temperatures below the glass transition temperature of, e.g., elastomeric components, to facilitate fibrillation.
The pressure of the fluid should be sufficient to impart some degree of fibrillation to at least a portion of the foam, and suitable conditions can vary widely depending on the fluid, the nature of the polymer, including the composition and morphology, configuration of the fluid jet, angle of impact and temperature. Typically, the fluid is water at room temperature and at pressures of at least 3400 kPa (500 psi), although lower pressure and longer exposure times may be used. In particular, a 5 mil thick (0.125 mm) oriented foam as described may be fibrillated with as little as 250 psi (1700 kPa). Such fluid pressure will generally impart a minimum of 5 watts or 10 W/cm 2 based on calculations assuming incompressibility of the fluid, a smooth surface and no losses due to friction.
The configuration of the fluid jets, i.e., the cross-sectional shape, may be nominally round, but other shapes may be employed as well. The jet or jets may comprise a slot which traverses a section or which traverses the width of the film. The jet(s) may be stationary, while the foam is conveyed relative to the jet(s), the jet(s) may move relative to a stationary foam, or both the foam and jet may move relative to each other. For example, the foam may be conveyed in the machine (longitudinal) direction by means of feed rollers while the jets move transverse to the web. Preferably, a plurality of jets is employed, while the foam is conveyed through the fibrillation chamber by means of rollers, while a screen or scrim, which allows the fluid to drain from the microfibrillated surface, supports the foam. The film may be fibrillated in a single pass, or alternatively the film may be fibrillated using multiple passes past the jets.
The jet(s) may be configured such that all or part of the foam surface is fibrillated. Alternatively, the jets may be configured so that only selected areas of the foam are fibrillated. Certain areas of the foam may also be masked, using conventional masking agents to leave selected areas free from fibrillation. Likewise the process may be conducted so that the fibrillated surface penetrates partially or fully through the thickness of the starting foam. If it is desired that the fibrillated surface extend through the thickness of the foam, conditions may be selected so that the integrity of the article is maintained and the foam is not severed into individual yarns or fibers.
Preferably the foam is supported using a screen having a predetermined pattern and/or mesh size. It has been found the use of such support screens will impart a pattern, corresponding to the screen pattern on the fibrillated surface. When fibrillating a biaxially oriented foam using a mesh pattern support screen, the resulting schistose surface bears a pattern resembling the warp and weft of a textile, rendering an article cloth-like in appearance. Screens may also be placed between the jet and the foam for use as a mask, moving with the foam during fibrillation. Masked portions of the foam will not be fibrillated, preserving the original properties of the foam in the masked areas. Patterned screens having an aspect ratio can impart a pattern to direct the tear of the film (for hand-tearable films and tapes) in a given direction. Useful support screens are available, for example, from Ron-Vik Inc., Minneapolis, Minn.
A hydroentangling machine, for example, can be employed to fibrillate one or both surfaces by exposing the fibrous material to the fluid jets. Hydroentangling machines are generally used to enhance the bulkiness of microfibers or yarns by using high-velocity water jets to wrap or knot individual microfibers in a web bonding process; a process also referred to as jet lacing or spunlacing. Alternatively a pressure water jet, with a swirling or oscillating head, may be used, which allows manual control of the impingement of the fluid jet.
The fibrillation may be conducted by immersing the sample in a high energy cavitating medium. One method of achieving this cavitation is by applying ultrasonic waves to the fluid. The rate of microfibrillation is dependent on the cavitation intensity. Ultrasonic systems can range from low acoustic amplitude, low energy ultrasonic cleaner baths, to focused low amplitude systems up to high amplitude, high intensity acoustic probe systems.
One method which comprises the application of ultrasonic energy involves using a probe system in a liquid medium in which the foam is immersed. The horn (probe) should be at least partially immersed in the liquid. For a probe system, the foam is exposed to ultrasonic vibration by positioning it between the oscillating horn and a perforated metal or screen mesh in the medium. Other methods of positioning are also possible. Advantageously, both major surfaces of the film are microfibrillated when using ultrasound. The depth of fibrillation in the fibrous material is dependent on the intensity of cavitation, amount of time that it spends in the cavitating medium and the properties of the foam, including the composition of the polymer and void content of the foam. The intensity of cavitation is a factor of many variables such as the applied amplitude and frequency of vibration, the liquid properties, fluid temperature and applied pressure and location in the cavitating medium. The intensity (power per unit area) is typically highest beneath the horn, but this may be affected by focusing of the sonic waves.
The method comprises positioning the foam between the ultrasonic horn and a film support in a cavitation medium (typically water) held in a tank. The support serves to restrain the film from moving away from the horn due to the extreme cavitation that takes place in this region. The foam can be supported by various means, such as a screen mesh, a rotating device that may be perforated or by adjustment of tensioning rollers which feed the film to the ultrasonic bath. Foam tension against the horn can be alternatively used, but correct positioning provides better fibrillation efficiency. The distance between the opposing faces of the foam and the horn and the screen is generally less than about 5 mm (0.2 inches). The distance from the foam to the bottom of the tank can be adjusted to create a standing wave that can maximize cavitation power on the foam, or alternatively other focusing techniques can be used. Other horn to film distances can also be used. The best results typically occur when the foam is positioned near the horn or at ¼ wavelength distances from the horn, however this is dependent factors such as the shape of the fluid container and radiating surface used. Generally positioning the sample near the horn, or the first or second ¼ wavelength distance is preferred.
The ultrasonic pressure amplitude can be represented as:
P 0 =2π B/λ= (2π/λ)ρ c 2 y max
The intensity can be represented as:
I= ( P 0 ) 2 /2 ρc
where
P 0 =maximum (peak) acoustic pressure amplitude
I=acoustic intensity
B=bulk modulus of the medium
λ=wavelength in the medium
Y max =peak acoustic amplitude
ρ=density of the medium, and
c=speed of the wave in the medium
Ultrasonic cleaner bath systems typically can range from 1 to 10 watt/cm 2 while horn (probe) systems can reach 300 to 1000 watt/cm 2 or more. Generally, the power density levels (power per unit area, or intensity) for these systems may be determined by the power delivered divided by the surface area of the radiating surface. However, the actual intensity may be somewhat lower due to wave attenuation in the fluid. Conditions are chosen so as to provide acoustic cavitation. In general, higher amplitudes and/or applied pressures provide more cavitation in the medium. Generally, the higher the cavitation intensity, the faster the rate of microfiber production and the finer (smaller diameter) the microfibers that are produced. While not wishing to be bound by theory, it is believed that high pressure shock waves are produced by the collapse of the incipient cavitation bubbles, which impacts the film resulting in fibrillation.
The ultrasonic oscillation frequency is usually 20 to 500 kHz, preferably 20-200 kHz and more preferably 20-100 kHz. However, sonic frequencies can also be utilized without departing from the scope of this invention. The power density (power per unit area, or intensity) can range from 1 W/cm 2 to 1 kW/cm 2 or higher. In the present process it is preferred that the power density be 10 watt/cm 2 or more, and preferably 50 watt/cm 2 or more.
The gap between the foam and the horn can be, but it is not limited to, 0.001 to 3.0 inches (0.03 to 76 mm), preferably 0.005 to 0.05 inches (0.13 to 1.3 mm). The temperature can range from 5 to 150° C., preferably 10 to 100° C., and more preferably from 20 to 60° C. A surfactant or other additive can be added to the cavitation medium or incorporated within the foam. The treatment time depends on the initial morphology of the sample, film thickness and the cavitation intensity. This time can range from 1 millisecond to one hour, preferably from {fraction (1/10)} of a second to 15 minutes and most preferably from ½ second to 5 minutes.
In the present process the degree of fibrillation can be controlled to provide a low degree or high degree of fibrillation, whether from a uni- or biaxially oriented foam. A low degree of fibrillation may be desired to enhance the surface area by producing a schistose or fibrous surface and thereby imparting texture to the surface of the foam. Thus the present invention provides an oriented, foamed article having a fibrillated surface.
The greater surface area consequently enhances the bondability to other surfaces. Such articles are useful, for example as substrates for abrasive coatings and as receptive surfaces for printing, as hook and loop fasteners, as interlayer adhesives and as tape backings. Conversely, a high degree of fibrillation may be required to impart a highly fibrous texture to the surface to provide cloth-like films, insulating articles, filter articles or to provide for the subsequent harvesting of individual fibers or flakes (i.e., removal from the foam polymer matrix).
In either fibrillation process most of the fibers or flakes stay attached to the foam web due to incomplete release from the polymer matrix. Advantageously the fibrillated article, having fibers or flakes secured to a foam, provides a convenient and safe means of handling, storing and transporting the fibers. For many applications it is desirable to retain the fibers or flakes secured to the foam. Integral fibers, for example, may be extremely useful in many filtering applications—the present fibrillated article provides a large filtering surface area due to the microscopic size of the fibers while the non-fibrillated surface of the foam may serve as an integral support.
Optionally the microfibers or flakes may be harvested from the foam by mechanical means such as a porcupine roll, scraper, and the like. Harvested microfibers generally retain their bulkiness (loft) due to the high modulus of the individual microfibers and, as such, are useful in many thermal insulation applications. If necessary, loft may be improved by conventional means, such as those used to enhance the loft of blown microfibers, for example by the addition of staple fibers.
The present invention provides foams with a high surface area which enhances performance when used as adsorbents, such as in oil-adsorbent mats or batts used in the clean up of oil spills and slicks. The instant fibrillated articles are also conformable and drapeable compared to fibrillated films. Other potential uses include reinforcing fibers in the manufacture of composite materials to enhance interfacial bonding, multilayer constructions where the wicking effect of the fibrous surface is used to enhance multilayer adhesion or integrity, and in mechanical fastener applications, e.g. hook and loop fasteners. The fibers are especially useful as a reinforcing agent in concrete, due to the high surface area (which aids bonding), tensile strength (which prevents crack formation and migration), and low elasticity. Fibrillated foams may also be useful as tape backings or straps to yield an strong tape with cross-web tearability. When used as a tape backing, the fibrillated foam can be coated with any conventional hot melt, solvent coated, or like adhesive suitable for application to films. Either a fibrillated surface or non-fibrillated surface may be coated, or both surfaces may be coated. Advantageously, when using a biaxially oriented fibrillated foam of the present invention, the adhesive tapes prepared therefrom may be more easily torn in both the longitudinal or transverse direction as compared to uniaxially oriented fibrillated foams.
Many types of adhesives can be used. The adhesive can include hot melt-coated formulations, transfer-coated formulations, solvent-coated formulations, water-based, and latex formulations, as well as laminating, thermally-activated, and water-activated adhesives. These adhesives can be applied by conventional techniques, such as solvent coating by methods such as reverse roll, knife-over-roll, gravure, wire wound rod, floating knife or air knife, and hot-melt coating such as slot orifice coaters, roll coaters or extrusion coaters, at appropriate coating weights.
Examples of adhesives useful in the invention include those based on general compositions of polyacrylate; polyvinyl ether; diene-containing rubber such as natural rubber, polyisoprene, and polyisobutylene; polychloroprene; butyl rubber; butadiene-acrylonitrile polymer; thermoplastic elastomer; block copolymers such as styrene-isoprene and styrene-isoprene-styrene block copolymers, ethylene-propylene-diene polymers, and styrene-butadiene polymer; poly-alpha-olefin; amorphous polyolefin; silicone; ethylene-containing copolymer such as ethylene vinyl acetate, ethyl acrylate, and ethyl methacrylate; polyurethane; polyamide; epoxy; polyvinylpyrrolidone and vinylpyrrolidone copolymers; polyesters; and mixtures of the above. Additionally, the adhesives can contain additives such as tackifiers, plasticizers, fillers, antioxidants, stabilizers, pigments, diffusing particles, curatives, and solvents.
Useful adhesives according to the present invention can be pressure sensitive adhesives. Pressure sensitive adhesives are normally tacky at room temperature and can be adhered to a surface by application of, at most, light finger pressure. A general description of useful pressure sensitive adhesives may be found in Encyclopedia of Polymer Science and Engineering, Vol. 13, Wiley-Interscience Publishers (New York, 1988). Additional description of useful pressure sensitive adhesives may be found in Encyclopedia of Polymer Science and Technology, Vol. 1, Interscience Publishers (New York, 1964).
A pressure sensitive adhesive may be coated onto one side of the backing and a release coating (a low adhesion backsize (LAB) coating) may be optionally coated on the opposite side to allow the resultant tape to unwind from itself when wound in a roll or to release when in a pad form.
When utilized, the release coating composition should be compatible with the adhesive composition and not degrade the adhesive properties of the tape, such as by being transferred to the adhesive composition.
Release coating compositions for the LAB layer of tapes may include silicone, alkyl, or fluorochemical constituents, or combinations as the release imparting component. Useful release coating compositions for the invention include silicone containing polymers, such as silicone polyurethanes, silicone polyureas and silicone polyurethane/ureas, such as those described in U.S. Pat. Nos. 5,214,119, 5,290,615, 5,750,630, and 5,356,706, and silicone acrylate grafted copolymers described in U.S. Pat. Nos. 5,032,460, 5,202,190, and 4,728,571. Other useful release coating compositions include fluorochemical containing polymers such as those described in U.S. Pat. No. 3,318,852, and polymers containing long alkyl side chains such as polyvinyl N-alkyl carbamates (e.g., polyvinyl N-octadecyl carbamates) as described in U.S. Pat. No. 2,532,011, and copolymers containing higher alkyl acrylates (e.g., octadecyl acrylate or behenyl acrylate), such as those described in U.S. Pat. No. 2,607,711, or alkyl methacrylates (e.g., stearyl methacrylate) such as those described in U.S. Pat. Nos. 3,502,497 and 4,241,198, where the alkyl side chain includes from about 16 to 22 carbon atoms.
These release polymers can be blended with each other and with thermosetting resins or thermoplastic film forming polymers to form the release coating composition. In addition, other additives may be used in the release coating compositions such as fillers, pigments, wetting agents, viscosity modifiers, stabilizers, anti-oxidants, and cross-linking agents.
Numerous other layers can be added to the tape, such as primers to increase adhesive layer adhesion to the backing layer. Also, the release properties of the backing can be modified such that the backing and the adhesive cooperate to achieve desired unwind characteristics. The release properties of the backing can be modified by applying a low surface energy composition, priming, corona discharge, flame treatment, roughening, etching, and combinations.
EXAMPLES
Test Methods
Foam Density (ASTM D792-86)
Foam samples were cut into 12.5 mm×25.4 mm specimens and weighed on a high precision balance available as Model AG245 from Mettler-Toledo, Greifensee, Switzerland. The volume of each sample was obtained by measuring the mass of water displaced at room temperature (25° C.). The density of the foam was obtained by the quotient of the mass and volume. Accuracy of this measurement is ±0.005 g/cm 3 .
Foam Cell Size
Scanning electron microscopy was performed on all the foam samples using a scanning electron microscope available as model JSM-35C from JEOL, Peabody, Mass. operated at 5 and 10 kV. The samples were prepared by freezing in liquid nitrogen for 2-5 minutes and fracturing. A thin palladium-gold coating was evaporated on the samples to develop a conductive surface. The diameters of the foam cells were measured using the digital SEM micrographs and UTHSCSA Image Tool for Windows Software (Version 1.28, University of Texas, San Antonio, Tex.). The diameters of over 100 cells were measured and recorded. The average cell diameter (x) and standard deviation (σ) of the cell diameter was calculated using the Image Tool Software.
1. Fibrillation of Uniaxially Batch Oriented Foam
A high melt-strength polypropylene resin (PF814™, Montell North America, Inc., Wilmington, Del.) was mixed with a chemical blowing agent, azodicarbonamide (Aldrich Chemical Co., Milwaukee, Wis.) at 3 wt % in a twin screw extruder at 40 rpm with an temperature profile from 160° C. to 216° C. to 182° C. over the six zones of the extruder, creating pressures from 6.2 MPa to 20.7 MPa. The temperatures in the melt pump and neck tube are maintained at 170° C. The impregnated polymer melt was extruded through a 15.2 cm wide foam die (available from Extrusion Dies Inc., Canfield, Ohio) and the resulting foamed polymer was collected on a chrome-plated roll chilled to 150° C. at a draw rate of approximately 3 meters/minute. Foam sheet thickness was approximately 1 mm (40 mils), density 0.56 g/cc, cell size less than 50 μm in largest dimension.
A sample of the foam sheet measuring approximately 5 cm×5 cm was stretched in the machine direction in a laboratory-scale batch orienter at 130° C. at a draw ratio of 5:1 and a rate of 20%/minute. Density of the sheet decreased to 0.42 g/cc as a result of orientation, while foam thickness decreased to approximately 0.25 mm.
Fibrillation of the stretched, foam sheet was carried out in a hydroentangling machine (Model 2303, Honeycomb Systems, Inc., Bridgeport, Me.) using deionized water at 23° C. and a line speed of approximately 1.5 m/min. Water at approximately 10.4 MPa (1500 psi) was sprayed through jets that were 0.127 mm diameter at 0.38 mm pitch. A fibrillated foam was produced wherein the fibers were between 10 μm and 80 μm thick, as viewed in a SEM image thereof.
2. Fibrillation of Continuously Uniaxially Oriented Foam
A foam sheet was prepared from high melt-strength polyproplyene as described in Example 1, except that the temperature profile was 190° C. to 225° C. to 175° C. over the six zones of the extruder, creating pressures from 11.0 MPa to 24.8 MPa. The foam exhibited a density of 0.43 g/cc and foam cell sizes of less than 50 μm in their largest dimension.
The sheet was fed into a continuous length-orienting stretcher and elongated at a 12:1 ratio at 120° C. to provide a foam sheet having a density of 0.30 g/cc.
Fibrillation of the drawn foam sheet was carried out as described in Example 1, to yield a cloth-like product having fibers less than approximately 10 μm thick with a high aspect ratio (length to thickness), according to an SEM image thereof.
3. Fibrillation of Uniaxially Batch-Oriented PP/Elastomer Blend.
A 70:30 blend (w/w) of high melt-strength polypropylene (PF814™, as described in Example 1) and elastomeric polypropylene (ENGAGE™ 8200, DuPont Dow Elastomers LLC, Wilmington, Del.) was extruded as a foam as described in Example 1, except that the temperature profile was 185° C. to 225° C. to 160° C. over the six zones of the extruder, creating pressures from 11.0 MPa to 24.8 MPa. Uniaxial orientation in a laboratory-scale batch orienter at 130° C. and a draw ratio of 5:1 produced a soft-feeling foam having a density of 0.38 g/cc.
The oriented foam was fibrillated using a hydroentangler, as described in Example 1, except that the water pressure was 8.3 Mpa (1200 psi). A fabric product having an excellent cloth-like hand was obtained. | A fibrillated foamed article and process for producing the same is described. The fibrillated articles are useful as tape backings, filters, thermal and acoustical insulation and as a diffuse reflector for use in optical applications such as computer displays and as reinforcement fibers for polymers or cast building materials such as concrete. | 2 |
This is a divisional of co-pending application Ser. No. 864,142 filed on May 16, 1986 now U.S. Pat. No. 4,701,360.
BACKGROUND OF THE INVENTION
The invention relates to heat sealable barrier laminates for the containment of essential oils and the prevention of loss of Vitamin C in paperboard cartons, as well as to a process for making such laminates. More particularly, this invention relates to barrier laminates which are composed of an improved heat-sealable product contact material which does not absorb or transmit flavor or odor ingredients of citrus and other juices.
Heat-sealable low-density polyethylenes are well known to be components of current paperboard citrus juice cartons which provide little barrier to absorption and/or transmission of citrus juice essential flavor/aroma oils. Additionally, it is well known that impermeable materials such as aluminum foil, polar materials such as: polyamides, polyethylene terephthalates, polyvinylidene chlorides, polyvinyl chlorides, etc., and highly crystalline non-polar materials such as high-density polyethylene and polypropylene provide varying degrees of barrier to the absorption and/or transmission of non-polar citrus juice flavor oils such as d-limonene, et al. However, these materials could not be substituted for low density polyethylene since they lacked the requisite heat-sealability over a practical temperature range, necessary FDA clearance for direct contact to foods, stress cracking resistance and cutability during the scoring, and/or die cutting conversion processes. Due to the failures of these impermeable materials, past efforts have concentrated on using a combination of these flavor-oil resistant materials with low density polyethylene as the heat-sealable component.
The existing commercial structure for a paperboard carton for juice and similar products has utilized an easily heat-sealable barrier laminate composed of paperboard sandwiched between two layers of low density polyethylene (LDPE). The LDPE is an inexpensive heat-sealable moisture barrier. The conventional structure falters in that the LDPE layer absorbs the essential oils of the juice after short periods of time causing integrity decay of heat seals, stress cracking of the layer and allows transmission of the essential oils into the paperboard and to the atmosphere. Additionally, the conventional structure provides virtually no barrier resistance to oxygen causing the juice to lose Vitamin C in large amounts.
One other conventional structure adds two additional layers to the structure identified above, namely a foil layer and an additional LDPE layer. The expensive foil layer increases barrier resistance to the flow of oxygen, while the additional LDPE allows for ultimate heat-sealability of the laminate. The improved conventional structure has poor barrier properties relating to the absorption of essential oils and aromas, since the interior contacting layer is still LDPE.
The object of the present invention is to produce an improved juice packaging heat-sealable laminate material which does not absorb or transmit flavor/odor ingredients of citrus and other juices.
SUMMARY OF THE INVENTION
The preferred embodiment of the present invention reveals a heat-sealable barrier laminate providing a substantial barrier to the loss of Vitamin C and an almost complete barrier to the loss of essential flavor oils over the shelf life period of the carton (six weeks) and far beyond the six week period as well. The preferred emmbodiment comprises from the outer surface to the inner surface contacting the essential oils and/or flavors: an exterior layer of a low density polyethylene, a paperboard substrate, an interior layer of a low density polyethylene and a layer of ethylene vinyl alcohol copolymer (EVOH) coated onto the interior layer of the low density polyethylene, in contact with the juice rendering the laminate heat-sealable.
The cartons constructed of the laminate of the present invention enable significant flavor oil retention of the citrus juice contained, and also significant prevention of loss of Vitamin C, resulting in a significant extension of the shelf life thereof and permits replacement of the costly aluminum foil barrier.
The preferred EVOH is sold under the product name Eval EP resins and is available from Eval Company of America.
The present invention has produced a suitable container which has excellent barrier properties utilizing a laminate which can be heat-sealed with its exterior and interior layers being a non-polar constituent (LDPE) and a polar constituent (EVOH) from front to back. The conventional theories have been that the laminate could not be heat-sealed on conventional apparatus at practical temperatures without having non-polar constituents on its ends. The liquid juice components are insoluble in the polar EVOH material, preventing flavor oil absorption and resulting swelling, stress cracking, and plasticization, heat seal degradation as occurs with LDPE as the contact layer.
The preferred laminate of the present invention not only exhibits significant barrier properties to extend the shelf life of the juice, but the laminate is produced using conventional extrusion equipment.
Stepwise, the paperboard is flame treated both sides, a layer of molten LDPE is placed onto the paperboard substrate by extrusion coating, the newly formed layer of LDPE is then corona discharge treated or flame treated in preparation for heat-sealing later in the process.
Secondly, the web is turned over and a layer of LDPE is extrusion coated onto fthe other exposed side of the paperboard substrate. This layer is also corona discharge treated or flame treated to facilitate adhesion to a subsequent EVOH layer.
Thirdly, a molten layer of EVOH is extrusion coated onto the interior layer of LDPE. The completed laminate can now be heat-sealed from front to back (LDPE to EVOH) at conventional temperatures (250° F. to 500° F.).
The newly formed laminate can then be scored, cut into blanks, folded and side-seam heat-sealed thereon for transport.
Once transported, the prepared blanks can be placed onto conventional equipment, such as a Purepak® machine made by Ex-Cell-O. The blanks are heat-sealed at the bottom, filled and heat-sealed at the top by the PurePak® machine to complete the filled carton.
The barrier laminate produced by the present invention not only exhibits excellent barrier properties and can be easily constructed but also meets FDA approval for use in food packaging. Eval Company of America's Eval EP is FDA approved for direct food contact and the preferred EVOH of the invention. Other EVOH's which heat seal at low temperatures (250° F. to 500° F.) and which can be cut on conventional machinery could also be used as the contacting barrier.
Thus, until the advent of the present invention no suitable containers for the containment of citrus juices have been developed which retain the advantages of using paperboard as the base material and is an FDA approved heat-sealable barrier laminate which is economical and can be formed using conventional extrusion coating equipment.
The present invention described herein is particularly useful as a paperboard laminate employed in the manufacture of citrus juice or other liquid containers. Such containers which make use of a heat-seal for seaming and closing such as folding boxes, square or rectangular containers or cartons, or even cylindrical tubes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional elevation of an existing commercial structure of a laminate;
FIG. 2 is a cross-sectional elevation of an existing commercial structure of a laminate;
FIG. 3 is a cross-sectional elevation of an existing commercial structure of a laminate;
FIG. 4 is a cross-sectional elevation of an existing commercial structure of a laminate;
FIG. 5 is a cross-sectional elevation of the preferred embodiment of the laminate of the present invention;
FIG. 6 is a cross-sectional elevation of an alternate embodiment of the laminate of the present invention;
FIG. 7 is a cross-sectinal elevation of an alternate embodiment of the laminate of the present invention;
FIG. 8 is a block diagram representing the process for making the preferred embodiment of the laminate of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The existing commercial structure for a paperboard carton for juice and similar products has made use of an easily heat-sealed barrier laminate composed of paperboard 4 (FIG. 1) sandwiched between two layers of low density polyethylene (LDPE) 2, 6. The LDPE is an inexpensive heat-sealable material which acts only to a limited extent as a moisture barrier to prevent loss of essential oils (flavor) and aroma. The problem encountered with conventional laminate structure has been that the essential oils of the juice (namely--D Limonene) has, after short periods of time, been absorbed into the LDPE layer causing heat seal decay, stress cracking, and swelling while stripping the juice of the essential oils. Additionally, the conventional structure (FIG. 1) provides virtually no barrier resistance to oxygen which causes the juice to lose Vitamin C in great quantities after a relatively short period of time. To illustrate, the conventional paperboard 1/2 gallon juice carton will lose 60.5% of its essential oil (D-Limonene) and 84.5% of its Vitamin C content in a storage period of six wweeks (SEE TABLE 1).
One conventional existing paperboard carton (FIG. 2) utilizes two additional layers in addition to the layers disclosed in FIG. 1 to add greater barrier resistance to the passage of oxygen and resultant loss of Vitamin C. Aluminum foil 14 has been added to the laminate structure to increase the barrier's resistance to the flow of oxygen. The additional layer of LDPE 16 is needed to allow the laminate to be heat-sealed from front to back with the exterior LDPE 8 layer. The structure of the barrier laminate (FIG. 2) has poor barrier properties relating to the absorption of essential oils and aromas, snce the heat-sealable contacting layer is still low density polyethylene. The shelf storage life of the juice carton made up of the barrier laminate of FIG. 2 still exhibits a percentage loss of essential oils (D-Limonene) of 35.5%, while greatly improving its barrier properties with respect to the percentage loss of Vitamin C, 24% (See Table 1). The addition of the foil layer allows the laminate to exhibit excellent O 2 barrier properties. Although, the use of a foil layer is extremely beneficial, the increased expense makes the use of foil economically less desirable.
FIGS. 3 and 4 disclose structures of barrier laminates described in U.S. Pat. No. 4,513,036. FIG. 3 discloses a barrier laminate comprising a sandwich of LDPE 18-paperboard 20-High Density Polyethylene (HDPE) 22-LDPE 24. The laminate disclosed exhibits large losses of essential oils during its shelf life of six weeks, namely 60.5%, while also exhibiting large losses of Vitamin C during the six week period 87% (see Table 1). The economics and ease of fabrication of the laminates of FIG. 3 are outweighed by the poor barrier properties exhibited.
FIG. 4 discloses the preferred embodiment of U.S. Pat. No. 4,513,036, namely a barrier laminate comprising LDPE 26-Paperboard 28-Polypropylene 30-LDPE 32. The additional polypropylene layer 30 adds to the barrier properties at relatively low additional costs. The barrier properties still are extremely deficient in its resistance to the passage of oxygen and its loss of Vitamin C, namely 71% after six weeks. The polypropylene laminate structure loses 39.5% of its essential oils (D-Limonene) after six weeks (see Table 1).
Both embodiments disclosed in the patent cited above do not adequately preserve the flavor/aroma and Vitamin C content of the juice. The structure of the existing commercial constructions have all faced the same problem due to the necessity for heat sealing the seams and closures while forming the carton blank and while filling the cartons with juice or the like. The necessity of forming a heat seal from the front to the back of the laminate has resulted in the use of an exterior layer of LDPE and an interior layer of LDPE, both non-polar compounds which exhibit excellent heat-sealing characteristics to one another (see FIGS. 1-4).
Referring to FIG. 5, the preferred embodiment of the laminate of the present invention is shown as comprising a paperboard substrate 36 which is most suitably high-grade paperboard stock, for example, 282 lb. Milk Carton Board, to which is applied on both sides a coating of low density polyethylene (LDPE) 34, 38 in a coating weight ranging from about 5 to about 40 pounds per ream. Any commercial extrusion coating grade LDPE is suitable for use herein. On the back or interior of the laminate, namely onto LDPE layer 38 is applied a layer of EVOH 40. The EVOH being a heat-sealable layer composed of Eval Company of America's Eval EP resins.
Referring now to FIG. 8, wherein a block diagram discloses the method of forming the heat-sealable barrier laminate of FIG. 5.
The laminate can be easily fabricated. In Step A, the paperboard is flame treated two sides. Step B, a molten layer of the LDPE 34 is extrusion coated onto the paperboard substrate 36. Step C, the LDPE layer 34 is corona discharge or flame treated in preparation for subsequent heat-sealing Step D, the web is turned over to facilitate Step E, which has a layer of molten LDPE 38 extrusion coated onto the paperboard substrate 36. Step F, LDPE layer 38 is corona discharge treated to facilitate the adhesion of a subsequent EVOH coating, and lastly, Step G, a layer of EVOH 40 is extrusion coated onto LDPE layer 38 to complete the sandwich.
Referring now to FIG. 6, an alternate embodiment of the laminate of the present invention is shown. The embodiment adds an additional barrier layer which not only provides total containment of flavor oils, but also provides significant containment of Vitamin C. In this alternate embodiment, the paperboard substrate 44 is extrusion coated on the external surface thereof with a coating of heat-sealable LDPE 42. On the internal surface of the paperboard substrate 44 is applied a coating of LDPE 46. Overlying the LDPE web 46 is a layer of an oxygen barrier material 48. The oxygen barrier material can be any of the following group: foil, polyacrylonitrile or its copolymers, polyethylene terephthalate or its copolymers, polyvinylidene chloride or its copolymers, polyamide or its copolymers, polyvinyl alcohols or its copolymers, polyvinyl chloride or its copolymers or an additional layer of EVOH. Overlying the barrier material is a layer of heat-sealable EVOH 50 which will ultimately form the internal surface of the container constructed therefrom.
To enhance the adhesion of the additional barrier layer 48 to the LDPE layer 46 and the EVOH layer 50, additional tie layers 47, 49 can be interposed therebetween. Adhesives which are extrudable or coextrudable, such as Dupont's CXA series or recent vintage Plexars® from Norchem are suitable choices. When using ethylene vinyl alochol (EVOH) as both an oxygen barrier 48 and a heat seal layer 50 in FIG. 6, tie layer 47 can be eliminated by coextrusion coating an EVOH 48/tie layer 49/EVOH 50 composite extrudate onto LDPE layer 46 which has been prevously flame or corona treated.
FIG. 7 reflects an embodiment similar to that of FIG. 5. Replacing the outer layer of a heat-sealable LDPE 34, is a blend layer 52 of EVOH and LDPE. The blend is made up of between five (5) to thirty (30) percent EVOH and the rest being LDPE. The laminate is comprised from outside to inside: LDPE/EVOH Blend 52-PAPERBOARD SUBSTRATE 54-LDPE 56-EVOH 58. The advantage of the LDPE/EVOH blend layer is that it eliminates the need for extensive surface treatment prior to heat sealing.
Although specific coating techniques have been described, any appropriate technique for applying the layers onto the paperboard substrate can be suitably employed, such as extrusion, coextrusion, or adhesive lamination or single and/or multilayer films to paperboard to achieve the stated inventions of this patent.
The unique barrier effect provided by the laminate of the present invention to the % loss of essential oils and to the % loss of Vitamin C is clearly demonstrated by the following example outlined in Table 1. Standard 1/2 gallon juice containers were prepared and filled with juice. A typical essential oil in the juice was d-limonene. The filled cartons were stored for a test period of six weeks after which the juice was analyzed to determine the percentage loss by weight of the essential oil d-limonene and the percentage loss by weight of Vitamin C.
The six cartons tested were those shown in FIGS. 1-6 and described herein.
TABLE 1______________________________________Test Sample % Loss1/2 Gallon Juice of Essential % Loss ofContainer Oil Vitamin C______________________________________LDPE-BOARD-LDPE (FIG. 1) 60.5 84LDPE-BOARD-LDPE-FOIL-LDPE (FIG. 2) 35.5 24LDPE-BOARD-HDPE-LDPE(FIG. 3) 60.5 87LDPE-BOARD-POLYPROPYLENE-LDPE (FIG.4) 39.5 71LDPE-BOARD-LDPE-EVOH(FIG. 5) 0* 30LDPE-BOARD-LDPE-EVOH-Tie Layer-EVOH (FIG. 6 with 0* 24tie layer)______________________________________ *Less than one percent
It can be clearly seen that the container prepared from a laminate of the present invention provides an almost complete barrier to the loss of essential oils far greater than has been present in existing structures comprising LDPE heat seal layers. Additionally, the oxygen passage or percentage loss of Vitamin C has been greatly reduced over all prior laminates not containing aluminum foil.
The effectiveness of the laminate of the present invention as a barrier to migration of essential oils and flavors, as well as a barrier to a loss of Vitamin C permits a significant extension of shelf life of containers constructed therefrom. | The present invention relates to an improved container for citrus juice and other liquids. The container utilizes a paperboard barrier laminate for the containment of essential oils and the prevention of losses of Vitamin C. Also disclosed is a process of making the laminate. The laminate makes use of a layer of a heat-sealable ethylene vinyl alcohol copolymer to enhance the barrier properties of the laminate. | 1 |
BACKGROUND OF THE INVENTION
When an inflatable such as a float, evacuation slide, or slide raft is used with a helicopter or aircraft, it is extremely important that the inflatable be properly positioned with respect to the craft to insure that it will function as intended. Positioning tubes or logs, inflatable from the same source as the inflatable, have been used both with respect to helicopter floats and evacuation slides. For example, refer to U.S. Pat. No. 3,598,215 assigned to the same assignee as this application.
In prior systems of the type, unrestricted openings have been provided between the inflatable and the positioning log with the same source of pressurized fluid used to inflate both. Thus when a load was applied to the inflatable, it would deform and be opposed by an equal resultant bearing load. With open communication between the inflatable and the log, the pressure in both remained essentially constant under load. Without any appreciable pressure increase in the log under load, the required contact area to maintain equilibrium increased as the applied load increased. As a result, the positioning log was either required to be larger and thus heavier to properly position the inflatable or a costly complex contoured shape was required.
SUMMARY OF THE INVENTION
A flow control for use between an inflatable, such as a helicopter float or aircraft evacuation slide, and an inflatable log which positions the float or slide with respect to the helicopter or aircraft. The flow control permits the inflation of the positioning log through the inflatable but restricts the flow of fluid back from the positioning log to the inflatable. Accordingly, the log can be of a simple configuration and smaller and lighter than would otherwise be required to properly position the inflatable under applied loads.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the helicopter float and positioning log on a helicopter;
FIG. 2 is a side elevation view of the helicopter float and positioning log of FIG. 1, partially cut away to show the flow control therebetween;
FIG. 2A is a partial side elevation view of the helicopter float and positioning log of FIG. 1, partially cut away to show a two cell positioning log;
FIG. 3 is an enlarged plan view of the flow control shown in FIG. 2;
FIG. 4 is a sectional view of the flow control taken along line 4--4 of FIG. 3;
FIG. 5 is a sectional view of the flow control taken along line 5--5 of FIG. 3;
FIG. 6 is an enlarged schematic view of the helicopter float and positioning log illustrating the flow control during inflation;
FIG. 7 is an enlarged schematic view of the helicopter float and positioning log illustrating the flow control at equilibrium; and
FIG. 8 is an enlarged schematic view of the helicopter float and positioning log illustrating their condition when a side load is applied to the helicopter float.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As generally shown in FIGS. 1 and 2 the inflated float 10 is positioned outward from the helicopter fuselage 12 by a positioning tube or log 14. The float 10 is held against the fuselage by inboard girths 16 and 18 and outboard girths 20 and 22. The helicopter will include both right and left side floats to establish a stable platform either on the ground or water. The greater the distance between the right and left hand floats, the greater the stability. Likewise, the helicopter would normally include both a fore pair of floats and an aft pair of floats. When in an uninflated condition, the forward floats are stored in compartments 24 in the helicopter fuselage 12. The flow control 26 is located between the float 10 and log 14.
Alternately, as shown in FIG. 2A, the float 10 and log 14 may be divided into more than one air holding cell or chamber separated by a bulkhead 23. In that case, each individual air holding cell will include a flow control device 26.
Both the float 10 and log 14 can be made of any suitable water impervious, air holding material or fabric such as a urethane elastomer coated nylon. Each is constructed to be a separate air holding chamber.
As shown in FIGS. 3, 4 and 5, the float 10 and log 14 are bonded, glued, or otherwise affixed together along the entire length of the log 14 and it is within this bond 28 that the flow control 26 is to be found. A crotch tape 29 is utilized to strengthen this bond. Within this bond 28, the float 10 includes an opening 30 and the log 14 includes a similar aligned opening 32. The flow control 26 is bonded to the interior of the log 14 over the aligned openings 30 and 32. The flow control 26 basically comprises a base 34 and flapper 36 both of the same or a similar fabric to that of the float and log. The base 34 includes an opening 38 of generally the same size and aligned with the openings 30 and 32 in the float 10 and log 14 respectively. The flapper 36 is bonded (e.g. heat sealed) to the base 34 at opposite edges 40 and 42 but is otherwise not affixed to the base 34. The flapper 36 includes a small central opening 44 generally aligned with the larger openings 38, 32 and 30.
FIG. 6 schematically illustrates the operation of the flow control 26 during inflation of the float 10 and log 14. Compressed fluid is provided from a compressed fluid source (not shown) to an inflation fitting 48 on the float 10. During the initial stages of inflation, the fluid under pressure flows into the float 10 and the float 10 begins to assume its cylindrical shape. As fluid pressure begins to build up in the float 10, this pressure acts to lift the flow control flapper 36 away from the flow control base 34. This permits the free flow of compressed fluid into the positioning log 14. Once the float 10 and log 14 are fully inflated, the pressure in the float and log will reach an equilibrium and the flapper 36 will return to its rest position on the base 34 as shown schematically in FIG. 7. The arrows are provided in FIG. 6 to generally illustrate the flow of compressed fluid. While the fluid pressure inside the float may vary depending upon the particular application, the useful pressure range will generally be between 0.75 psig and 6.0 psig.
Whenever a side load (shown as a large arrow) is applied to the helicopter float 10 as schematically illustrated in FIG. 8, the float 10 is caused to rotate clockwise toward the positioning log 14. Since the flow control 26 restricts the flow of fluid from the log 14 to the float 10, the log 14 is thus compressed and the pressure rises therein. Since the ideal gas laws state that pressure is inversely proportional to the volume, the pressure rises as the volume is compressed. This increased pressure restricts and otherwise reduces the inboard motion of the float 10. The small hole 49 in the flow control flapper 36 prevents the buildup of an excessive pressure in the log 14.
If the final equilibrium pressure of the float 10 and log 14 is assumed to be 0.75 psig and a side load in the order of magnitude of 300 pounds is applied as shown in FIG. 8, the internal fluid pressure would rise to the neighborhood of 3.5 psig. It is known that the contact area (bearing surface) between the aircraft and an inflatable is inversely proportional to the inflation pressure of the inflatable and directly proportional to the applied force. This can be expressed in equation form as:
A=F/P
where
A is the contact area in square inches,
F is the applied force in pounds, and
P is the internal fluid pressure in pounds per square inch.
Under an applied load, the inflatable, in this case the float 10, will deform to a point where the applied load is opposed by an equal resultant bearing load. If the pressure in the log increases as the applied load increased, as it will if the flow of gas is prevented from leaving the log, the required contact area will not increase directly. Where there is no flow control between the float and log, that is there is open communication, the pressure in the log will remain essentially constant under an applied load since the total volume of the log and float is very large as compared to the applied load. Thus in case of open communication, in order to maintain equilibrium as applied load increased, the required contact area likewise increased almost proportionally.
In designing a positioning log, it is obviously desirable to provide the smallest and lightest log which is still capable of performing the required function. Its size can be determined from the expected applied load and the design fluid pressure for the inflatable. The equation above then permits the determination of the required contact area under any given condition. Patterning the log as a cylinder, the length and diameter can be calculated directly from the required contact area.
Since the pressure in the log will increase under applied load, a smaller lighter log can be utilized with the flow control. It thus provides the same advantages of a contoured shape without the complex patterning required to produce it.
While specific embodiments of the invention have been illustrated and described, it is to be understood that these embodiments have been provided by way of example only and that the invention is not to be construed as being limited thereto, but only by the proper scope of the following claims. | A flow control is provided between an inflatable and a smaller inflatable log which positions the inflatable with respect to the craft to which it is affixed. The flow control permits the inflation of the positioning log through the inflatable but restricts the flow of fluid back from the positioning log to the inflatable. | 8 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to an optical fibre grating sensor system and to a method for increasing the number of measurement sites in such a system. In particular, the invention relates to a system and method using Fibre Bragg (FBG) or Long Period Fibre (LPG) Gratings, and contemplates the use of the system applied to a wind turbine power plant.
[0002] Wind turbine components are subject to temperature variation from a number of sources, such as environmental temperature change, and heat generated in components. Consequently, it is important that the temperature of those components is monitored to ensure that they are operating within appropriate ranges.
[0003] In addition, wind turbine components are subject to deformation or strain from a number of sources, such as the accumulation of particulates like dirt or ice, their own weight, and the force exerted by the wind itself. Consequently, it is important that the strain on components be monitored to ensure that they remain fit to operate over their intended working lives.
[0004] An FBG sensor is an optical fibre in which an optical grating is formed. The grating itself is typically a periodic variation in the refractive index of the fibre, tuned to reflect a particular wavelength of light. The region of the optical fibre having the grating is then attached to the region of the wind turbine component where an operating condition such as temperature or strain is to be measured. It is attached in such a way that any deformation, strain or temperature change experienced by the component is transmitted to the fibre and to the grating. Temperature variation, deformation and strain causes the spacing and the refractive index of the grating to change, and causes a detectable change in the wavelength of light reflected back or transmitted by the grating. Various arrangements are known for inserting light into the FBG sensors and for extracting and analysing the output.
[0005] Long Period Fibre Gratings operate in a similar manner to FBGs but instead couple light of particular wavelengths travelling in the core to the cladding where it is subsequently lost due to absorption or scattering.
[0006] A number of techniques for mounting fibre optic sensors on wind turbine components are known, such as attaching the fibre optic cable by means of brackets, or hollow casings, or locating the sensor within a capillary tube that can be embedded, tube and all, in a composite material. When attaching a fibre optic sensor, it is important that the sensor will not be damaged by the mounting means, either when the cable is mounted or later during the operational life of the sensor. However, for strain sensors, it is also important that the sensor be sufficiently sensitive to strain on the component.
[0007] Present FBG sensors pose a number of disadvantages. In particular, in order to measure temperature, or strain, at a number of different locations a series of FBGs need to be used, each FBG being tuned to a different wavelength. In addition, the range of wavelengths that each FBG operates over need to be distinct from each other FBG's range of operating wavelengths. This is illustrated by way of example in FIG. 8 . This is necessary to enable a single wavelength to relate to a specific FBG and a specific operating condition. Such systems require a broad band light source and a broad band interrogator, or a narrow band tunable light source, which results in significant overall cost of the system. LPGs suffer from similar problems.
[0008] We have appreciated that there is a need for a more cost effective solution for detecting temperature changes and/or deformation at multiple locations in a wind turbine component.
SUMMARY OF THE INVENTION
[0009] The invention is defined in the independent claims to which reference should be made. Advantageous features are set forth in the dependent claims to which reference should be made.
[0010] According to a first aspect of the present invention, there is provided an optical fibre sensor system for measuring at a plurality of locations an operating condition, the sensor comprising: a sensor optical fibre; a light source for inputting light into the sensor optical fibre; a light detector for receiving light from the sensor optical fibre; and a processor for outputting measurements of the operating condition corresponding to the plurality of locations based on light received at the light detector. The optical fibre sensor comprises a plurality of optical gratings, each grating in use being disposed at a respective location on the wind turbine component and arranged to operate over a respective range of wavelengths depending on variations in the operating condition. A first of the plurality of gratings is a master grating and is arranged to operate over a first wavelength range, the first wavelength range being distinct from a second range of wavelengths over which the other gratings are arranged to operate. The other gratings are arranged such that the respective wavelength ranges over which they operate are spaced apart from the first wavelength range by a respective predetermined interval and such that they overlap with the respective wavelength range of at least one of the other gratings. The processor is operable to determine the value of the operating condition at the location of the master grating from the wavelength value received in the first wavelength range, and to determine the value of an operating condition at the location of one of the other gratings based on the wavelength value received in the first wavelength range, a wavelength value received in the second wavelength range, and the predetermined intervals by which the overlapping ranges are spaced apart from one another.
[0011] The term “arranged to operate” as used herein means interact with light at a wavelength that falls within the allocated range of wavelengths and that varies within the range depending on variations in the operating condition”.
[0012] By providing such an optical fibre sensor system, advantageously the cost of a sensor for measuring multiple operating conditions may be reduced. The cost may be reduced since the range of wavelengths that the light source, and the light detector, operate over can be reduced for the same number of measurements. Alternatively, advantageously, there may be an increase in the number of measurements that can be made for a given light source capable of emitting a fixed range of wavelengths.
[0013] Preferably, the light having a wavelength in the first wavelength range is uniquely indicative of the value of the operating condition at the location of the master grating.
[0014] Preferably, the processor is operable to determine a reference wavelength value for a first one of the other gratings, the reference value indicating for the first one of the other gratings, the wavelength in the grating's respective range of wavelengths that corresponds to the value of the operating condition measured at the master grating. In this case, the reference wavelength value for the grating is calculated by adding or subtracting the respective predetermined interval from the wavelength value received in the first wavelength range.
[0015] Preferably, the processor is operable to determine the value of the operating condition at the first one of the other gratings by determining the difference between the reference wavelength value for the grating and the closest received wavelength value.
[0016] Preferably, the amount by which the respective ranges of wavelengths of the other gratings overlap is such that for each of the other gratings there is a range of unambiguous wavelengths that are unique for that grating and a range of ambiguous wavelengths that overlap with the wavelengths of the adjacent grating.
[0017] The sensor system may also comprise a memory. In this case, the processor is operable to store a time series of measurements of wavelength in the memory for each of the other gratings, and the processor is operable to determine the value of the operating condition at the first one of the other gratings by determining the difference between the reference wavelength value and a received wavelength value falling in the ambiguous wavelengths for the first one of the other gratings, and by comparing the received wavelength value to historic values of the wavelength in the time series of measurements.
[0018] Preferably, the second wavelength range is divided into lower and upper second wavelength ranges, and the first range of wavelengths lies in between the lower and upper ranges.
[0019] Preferably, the first and second wavelength ranges are separated from one another by a margin of unused wavelengths.
[0020] According to a further aspect of the present invention, there is provided a method of operating an optical fibre sensor system, the system comprising a sensor optical fibre having a plurality of optical gratings, each grating in use being disposed at a respective measurement location and arranged to operate over a respective range of wavelengths depending on variations in an operating condition of the measurement location, the method comprising: allocating a first range of unique measurement wavelengths to a master grating in the optical fibre; allocating respective ranges of measurement wavelengths to further gratings in the optical fibre, wherein the ranges allocated to the further gratings are distinct from the first range of unique measurement wavelengths and separated from the first range by predetermined intervals, and wherein the ranges allocated to each of the further gratings overlap with at least one other of the further gratings; determining the value of the operating condition at the location of the master grating from a wavelength value received in the first range of unique measurement wavelengths; determining the value of an operating condition at the location of one of the other gratings based on the wavelength value received in the first wavelength range, a wavelength value received in the wavelength ranges allocated to the further gratings, and based on the predetermined intervals by which the overlapping ranges are spaced apart from one another.
[0021] Preferably, the method further comprises determining a reference wavelength value for a first one of the other gratings, the reference value indicating for the first one of the other gratings, the wavelength in the grating's respective range of wavelengths that corresponds to the value of the operating condition measured at the master grating, and the reference wavelength value for the grating is calculated by adding or subtracting the respective predetermined interval from the wavelength value received in the first wavelength range. More preferably, the method also comprises determining the value of the operating condition at the first one of the other gratings by determining the difference between the reference wavelength value for the grating and the closest received wavelength value.
[0022] Preferably, the amount by which the respective ranges of wavelengths of the other gratings overlap, such that for each of the other gratings there is a range of unambiguous wavelengths that are unique for that grating and a range of ambiguous wavelengths that overlap with the wavelengths of the adjacent grating.
[0023] Preferably, the method further comprises: storing a time series of measurements of wavelength in the memory for each of the other gratings, and
[0000] determining the value of the operating condition at the first one of the other gratings by determining the difference between the reference wavelength value and a received wavelength value falling in the ambiguous wavelengths for the first one of the other gratings, and by comparing the received wavelength value to historic values of the wavelength in the time series of measurements.
[0024] Preferably, the second wavelength range is divided into lower and upper second wavelength ranges, and the first range of wavelengths lies in between the lower and upper ranges.
[0025] Preferably, the first and second wavelength ranges are separated from one another by a margin of unused wavelengths.
[0026] According to a yet further aspect of the present invention, there is provided a computer program product having computer code stored thereon which when executed on a processor causes the processor to carry out a method as described herein.
[0027] According to a still further aspect of the invention there is provided an optical fibre for a fibre optic sensor. The optical fibre comprises a first Fibre Bragg Grating adapted to operate over a first range of wavelengths, and at least one set of further Fibre Bragg Gratings adapted to operate over a second range of wavelengths. Each Fibre Bragg Grating within the set is adapted to operate over a portion of the second range of wavelengths. Furthermore, each Fibre Bragg Grating within the set has an operating range that partially overlaps with at least one other such Fibre Bragg Grating operating range. By providing an optical fibre with a set of Fibre Bragg Gratings with overlapping wavelength ranges, advantageously the cost of a sensor for measuring multiple operating conditions may be reduced. The cost may be reduced since the range of wavelengths that the light source, and the light interrogator, operate over can be reduced for the same number of measurements. Alternatively, there may be an increase in the number of measurements that can be made for a given light source capable of emitting a fixed range of wavelengths.
[0028] Preferably, the first range of wavelengths does not overlap with the second range of wavelengths. This enables the first grating to be used to unambiguously determine a range of expected operating conditions for the other gratings.
[0029] The optical fibre may also comprise a second set of further gratings adapted to operate over a third range of wavelengths. Each grating in the second set is adapted to operate over a portion of the third range, and each grating within the set has an operating range that partially overlaps with at least one other such grating operating range. Providing a second set of gratings enables more measurements to be made by a single optical fibre.
[0030] Preferably, the first range of wavelengths is between the second range and the third range. By providing the first range of wavelengths in the middle of the two other ranges of wavelengths, a single grating may be used to unambiguously determine two ranges of expected operating conditions, the first range for the first set of gratings and the second range for the second set of gratings.
[0031] According to a still further aspect of the present invention, there is provided a fibre optic sensor comprising at least one optical fibre as described herein. The fibre optic sensor also comprises a light source for feeding light into the at least one optical fibre, a light detector for detecting light that has travelled along the at least one fibre, and a controller for determining, from the detected light, the wavelengths of light interacting with the gratings. This arrangement allows the sensor to be implemented using only a small number of optical components, and therefore provides advantages in cost, installation and maintenance.
[0032] The invention extends to apparatus and/or methods substantially as herein described with reference to the accompanying drawings.
[0033] Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. In particular, method aspects may be applied to apparatus aspects, and vice versa. Furthermore, any, some and/or all features in one aspect can be applied to any, some and/or all features in any other aspect, in any appropriate combination.
[0034] It should also be appreciated that particular combinations of the various features described and defined in any aspects of the invention can be implemented and/or supplied and/or used independently.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Preferred embodiments of the invention will now be described, by way of example, and with reference to the drawings in which:
[0036] FIG. 1 illustrates a known wind turbine;
[0037] FIG. 2 . illustrates an optical fibre according to the invention;
[0038] FIG. 3 illustrates an optical fibre sensor according to the invention;
[0039] FIG. 4 illustrates a controller according to the invention;
[0040] FIGS. 5( a ) and 5 ( b ) illustrate the wavelength ranges allocated to variations in temperature of an optical fibre according to the invention;
[0041] FIGS. 6( a ) and 6 ( b ) illustrate sample wavelength outputs for two uniform but different temperatures;
[0042] FIG. 7 illustrates sample wavelength outputs for the case where the local temperatures are different; and
[0043] FIG. 8 illustrates the prior art wavelength allocation.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0044] FIG. 1 illustrates a wind turbine 1 , comprising a wind turbine tower 2 on which a wind turbine nacelle 3 is mounted. A wind turbine rotor 4 comprising at least one wind turbine blade 5 is mounted on a hub 6 . The hub 6 is connected to the nacelle 3 through a low speed shaft (not shown) extending from the nacelle front. The wind turbine illustrated in FIG. 1 may be a small model intended from domestic or light utility usage, or may be a large model, such as those that are suitable for use in large scale electricity generation on a wind farm for example. In the latter case, the diameter of the rotor could be as large as 100 metres or more.
[0045] FIG. 2 illustrates one example of an optical fibre for use in an optical fibre sensor system according to the invention. Although in this example, the optical fibre described contains a plurality of gratings, it will be appreciated that the optical fibre according to the invention could be constructed with a plurality of LPGs, or indeed any other suitable wavelength-selective optical grating.
[0046] The optical fibre 200 comprises a fibre core 201 , and a fibre cladding 202 . The fibre core is provided with two sets of Fibre Bragg Gratings (FBGs) 203 , 204 , 205 , 206 and 207 in FBG set 208 , and FBGs 209 , 210 , 211 , and 212 in FBG set 213 . The FBG sets 208 and 213 correspond to FBGs A to D and F to I respectively in FIGS. 5( a ) and 5 ( b ), while FBG 203 corresponds to FBG E. Each FBG is tuned in the sense that it will reflect a different wavelength of light determined by the grating dimensions. If the section of the optical fibre 20 having an FBG is placed next to or in contact with a wind turbine component, then the changes in the length of the optical fibre at that location (for example, due to a temperature change of the component or a change in strain), will result in a change in both the dimensions of the FBG and the refractive index of the optical fibre. Both effects alter the wavelength of any light reflected and/or transmitted by the FBG, which can therefore be used as a measure of the temperature or strain of the component at that location.
[0047] FIG. 3 illustrates an embodiment of an optical fibre sensor system according to an example of the invention. The sensor 300 comprises a light emitting device 301 , such as an LED, laser, halogen or metal halide source, a light collecting measuring device or detector 302 , such as a photo-sensor, and an optical fibre 200 (for conciseness only FBG set 208 is shown). The light emitting device is connected to one end of the fibre optic cable to input light into the fibre, and the light measuring device (such as an interrogator) is connected to the other to receive light transmitted along the fibre. An interrogator is a light detector that detects and measures light across a wide spread of wavelengths. A controller 303 is connected to both light emitting device 301 and light measuring device 302 , by connections 304 and 305 , such as wires or cables. Components 301 to 305 may be housed in a mounting box, or the like, for easy attachment to the inside or outside of a wind turbine component.
[0048] FIG. 4 illustrates the controller 303 as described above with reference to FIG. 3 . The controller comprises a light source controller 400 , coupled to the light source 301 . The light source controller is used to determine when the light source is operated.
[0049] The controller also comprises a memory 401 for storing the output received from the light detector. An analyser 402 , such as a processor, and coupled to the memory, is provided to analyse the output from the light detector 302 stored in memory and determine the wavelengths of light reflected by the FBGs. There are two alternatives available for determining the wavelengths of light reflected by the FBGs. Either the wavelengths are measured directly by having the light detector 302 positioned at the same end of the optical fibre 200 as the light source 301 , or by detecting the difference between the light profile provided by the light source, and the light received at the other end of the optical fibre.
[0050] A calculation unit 403 is coupled to the analyser 402 to calculate the difference between the wavelength received from each FBG and a reference wavelength expected if there were no temperature or strain difference, for example, between the FBGs (A, B, C or D) and FBG E. The calculation unit 403 is also coupled to the memory 401 . The memory 401 is adapted to store a look-up table, and the look-up table is provided to allow the calculation unit to look-up the expected range of wavelengths for each FBG. The calculation unit then determines the value of the operating condition measured by FBG.
[0051] The controller further comprises an input/output line 404 for receiving and transmitting instructions or data to and from a remote site, such as a monitoring station. The input/output line may be wired or wireless.
[0052] Additionally, error detection can be incorporated into the controller 303 . If no wavelength is detected within the expected range for a particular FBG, then this could be an indication of a fault. This could be the result of a breakdown in the coupling between the operating conditions being measured, or that the FBG itself is faulty.
[0053] Although the controller has been described in terms of separate hardware components, this is solely to illustrate the functionality of the controller in a clear manner. It would be possible in practice to provide the hardware components as software or hardware, or as any combination of single or combined components.
[0054] The optical fibre 200 is mounted on or in a wind turbine component (not shown in FIG. 3 ) to measure the strain in the component, or indeed any other suitable operating condition of the component, such as temperature. In one example, this may be achieved by mounts attached to the outside or inside surface of the component. Other mounting methods would be acceptable as would be known to the skilled person. If the sensor were to be installed in a wind turbine to measure the strain in the wind turbine blades, it is likely that the mounting box would be situated in the hub 6 , and the optical fibre 200 would extend internally within the blade from the hub to the relevant region of the blade to be assessed. In this way, the aerodynamic properties of the blades are not affected by the presence of the sensor. In other locations, the optic fibre sensor may be mounted on the outside of the component.
[0055] The optical fibre sensor system described can therefore be utilised to measure a number of operating conditions, one operating condition per FBG. However, it is required that those operating conditions are coupled (i.e. that an increase in one operating condition results increase in the other operating conditions, and vice versa). For example, the operating conditions could be the temperature of a number of components housed within the electrical housing of a wind turbine since it would be expected that a rise in temperature of one component would lead to a rise in temperature of another component, and vice versa. The overall range of temperatures that could be measured can be large, for example from −40 degrees C. to 60 degrees C.
[0056] The operation of the optical fibre sensor system will now be described in more detail, and with reference to FIGS. 2 , 5 a and 5 b . In this example, the use of the sensor to detect temperature only will be described. The operation of the sensor will be the same for other operating conditions that are to be measured. Furthermore, in this example, it is assumed that the FBGs are configured to reflect light back to the detector, rather than transmit light to a remote detector at the end of the optical fibre 200 . In practice, either or both configurations are acceptable.
[0057] As shown in FIG. 2 , optical fibre 200 comprises a number of FBG's A to I, each tuned to a different wavelength and each located at a different location on the component where measurements are to be taken. As shown in FIG. 5 a , FBG E is tuned to a first default wavelength, lying in the middle of the range of wavelengths of light that can be transmitted along the optical fibre 200 and detected by the light detector 302 .
[0058] Also as shown in FIG. 5 a , a first range of measurement wavelengths is allocated to FBG E for use, which corresponds to the range of temperatures that FBG E will be used to detect. In FIG. 5 a , the range of wavelengths is illustrated as extending between λemin and λemax, with λemid signifying the middle value of the range.
[0059] In practice, therefore, if the FBG E is required to detect temperatures in the range of say −40 to 60 degrees C., the FBG E will be constructed in the optical fibre 200 so that when the optical fibre 200 at FBG E is at −40 degrees C., the wavelength of light reflected by the FBG E will equal λemin, and so that when the optical fibre 200 at FBG E is at 60 degrees C., the wavelength of light reflected by the FBG E will equal λemax. Assuming linear variation of the FBG wavelength with temperature therefore FBG E will reflect light at λemid at 10 degrees. Using FBG sensors in this way is well known, and the appropriate wavelengths to correspond to the desired temperature can be calculated, read off product sheets for the optical fibre, or determined by simple experiment.
[0060] As shown in FIG. 5 a , FBG E is allocated a unique and distinct range of wavelengths for the expected range of the operating parameter being measured. Thus, if a light signal is received having a wavelength in the range of λemin and λemax, the controller 303 can unambiguously recognise that signal as being representative of the temperature of FBG E (and therefore the temperature of the component at that location) and no other. As the light signals from FBG E can always be detected unambiguously, FBG E shall be referred to as a calibration FBG.
[0061] Similarly, FBGs A to D and F to I are allocated respective ranges of wavelengths between λnmin and λnmax (where n is representative of A, B, C, D, F, G, H and I). It is assumed that each of the FBGs will operate over the same range of temperatures as FBG E, and in this example therefore, each FBG will be used to detected temperatures in the range −40 to 60 degrees C. but at different locations of the component. As above, each FBG will be constructed so that as the temperature of the FBG varies, the wavelength of light reflected varies between the maximum and minimum allotted wavelength values.
[0062] In the prior art example discussed above with reference to FIG. 8 , each of the FBGs A to D and F to I would therefore require a unique range of operating wavelengths to be distinguished from one another and provide unambiguous temperature measurements in the manner described for FBG E. However in this case, as illustrated in FIG. 5 a , the respective ranges of wavelengths of the FBGs A to D and F to I are overlapped with at least one adjacent FBG (excluding FBG E). This advantageously provides a reduction in the total range of wavelengths that must be accommodated by the fibre and the sensor system, but does mean that in certain scenarios the signals provided by each of the FBGs A to D and F to I are no longer unambiguous. As the ranges of adjacent wavelengths overlap with one another, it is possible that a light signal received from the optical fibre 200 corresponds to more than one possible value of temperature and location. Calibration FBG E is therefore used to determine the expected range of temperatures measured at FBGs A to D and FBGs F to I (this can be achieved as it assumed that the locations where the FBGs are located are thermally coupled, meaning that there will be some correspondence between temperatures at different locations) as well as distinguish the values of the different FBGs from one another. For this reason FBGs A to D and F to I will be referred to as subsidiary FBGs, to indicate their dependence on calibration FBG E.
[0063] As shown in FIG. 5 a , FBG E is constructed to operate over wavelengths λemin to λemax. FBGs A to D are allocated lower ranges of wavelengths in comparison to the range allocated to FBG E, while FBGs F to I are allocated higher ranges. In this example therefore the range of wavelengths allocated to FBGs D and F are adjacent to that allocated to FBG E. The minimum allocated wavelength of FBG F λfmin and the maximum allocated wavelength of FBG D λdmax are separated from the range for FBG E by a tolerance value α. This tolerance value is intended to accommodate any imprecision in the manufacturing technique and allow for possible deviations in the constructed wavelength of the respective FBGs.
[0064] Each allocated range of wavelengths will necessarily have a midpoint λnmid around which the range is centered. Taking the calibration FBG E initially, the maximum expected variation of wavelengths for FBG E is the range of wavelengths between the midpoint λemid and either λemin or λemax. In this example, the difference in the base wavelengths of each of the ranges for FBGs A to D or FBGs F to I (that is the difference between λamin and λbmin for example) is set to be this maximum variation for FBG E plus the tolerance alpha. This ensures that the overlapping ranges of wavelengths are not spaced out too much (in which case the reduction in bandwidth is diminished), but are also not too close together (in which case the accuracy of the sensor could be impaired).
[0065] Referring now to FIG. 5 b , it can be seen that this results in ranges of wavelengths that overlap, but that for each range of wavelengths there is a central portion that remains unambiguous, and overlapping portions where for the expected range of operating temperatures, a single wavelength could fall in the range of wavelengths allocated to both of two adjacent FBGs.
[0066] A number of different example modes of operation will now be explained, to illustrate how the controller 303 processes the light signals received from the optical fibre 200 and resolves any ambiguities between signals received from different FBGs.
[0067] In the first example, it is assumed that the temperature of the optical fibre 200 is the same at each of the different FBG locations A to I. Light source controller 400 instructs light source 301 to input light into the optical fibre 200 , and as a result light is reflected back from each of the FBGs A to I and is detected at light detector 302 . Analyser 402 scans through the nine signals received from the respective FBGs A to I to detect the signal reflected back by calibration FBG E. The signal from FBG E can be distinguished from the other FBGs as (assuming the temperature of the component has not gone outside of the expected range of temperatures) it will always lie in the dedicated range of unique wavelengths λemin or λemax. From the measurement λe the temperature of the component at location E can be determined by analyser 402 and calculation unit 403 . This value will also be stored in memory 401 with a time stamp information. Referring to FIG. 5 b , this first temperature is denoted as T1.
[0068] As the relationship between the wavelength ranges of FBG E and FBGs A to D and F to I is known, the wavelength of the light signals reflected by the FBGs A to D and F to I when those FBGs are all at the same temperature can be calculated by the analyser and calculation unit 403 . The wavelength of light that corresponds to the same temperature as the FBG E shall be referred to as the reference wavelength for the FBG (it will be appreciated that this will vary with variations in temperature).
[0069] As the size of the wavelength range is the same for each FBG, the difference in expected wavelengths between FBGs E and D at the same temperature can be given by the difference in the centre of the ranges (λemid-λdmid) for example (the minimum or maximum values of the ranges could also be used). Similarly, the difference in expected wavelengths between FBGs E and C at the same temperature can be given by the difference in the centre of the ranges (λemid-λcmid) for example (again the minimum or maximum values of the ranges could also be used). Thus, as shown in FIG. 5 b , once the value of T1 is determined absolutely from FBG E, the wavelengths for the same temperature T1 at each of the different locations A to D and F to I can be readily determined by subtraction or addition of a respective predetermined interval. This interval will be different for each FBG range, and may be measured relative to the adjacent FBG range or to the range of wavelengths for FBG E.
[0070] Further, as shown in FIG. 5 b , it will be appreciated that assuming the optical fibre is uniformly disposed at a second lower temperature T2, the respective wavelengths of the signals reflected back by the FBGs in this case will be lower, but that the interval between the respective wavelengths will be the same in both cases. This is illustrated in FIGS. 6 a and 6 b for temperatures T1 and T2. In use therefore, if the analyser 402 and calculation unit 403 , having determined the temperature at E also determine the regular spacing of wavelengths indicated in FIGS. 6 a and 6 b it can deduce that the optical fibre is at a uniform temperature.
[0071] In FIG. 5 b , the horizontal bars A, B C and D underneath the wavelength axis indicate how the ranges of wavelengths that can be detected at the FBGs A to D will change with temperature. As the temperature at FBG E varies the other FBG's usable measurement range of wavelengths slides up or down the wavelengths available. For temperature T1 for example the analyser 402 and calculation unit 403 assume that each of the FBGs A to D are operating in the unshaded unambiguous wavelength range indicated directly underneath the wavelength axis. For, temperature T2, those ranges of unambiguous wavelengths are shifted down. Due to the assumed thermal coupling between FBG E and the other FBGs, once the temperature at FBG E is determined, the expected operating range at the other subsidiary FBGs can be readily determined.
[0072] In practice, the temperature at the locations being monitored by the other FBGs A to D and I to F will not be identical to FBG E, and the signals reflected back to the light detector 302 and the analyser 402 will not exhibit the regular spacing illustrated in FIGS. 6 a and 6 b , but will be spaced irregularly as shown in FIG. 7 . In this case, the irregular spacing is indicative of the temperature differences at each location. To determine the actual temperature of each of the FBGs, the calculation unit therefore determines the difference between the reference wavelength (referred to as λn_ref) of FBG n, assuming that FBG n is at the same temperature as FBG E, and the actual signal that is detected from FBG n. λn_ref is calculable once Te is known, as explained above, and calculating the difference to give a temperature reading at FBG n is therefore simply a matter of subtraction or addition as shown in FIG. 7 .
[0073] This case assumes that the actual wavelengths reflected back from the various FBGs all lie in the unshaded ranges of FBG wavelengths illustrated in FIG. 5 b . These unshaded wavelengths are unambiguous as once they are calibrated with respect to FBG E, it is possible to assume to a high degree of confidence that a received signal in that range was reflected from a particular FBG and no other. It will be appreciated for example that if the light signal falling into that wavelength range had in fact been reflected by the FBG (n+1/n−1) adjacent to the expected FBG n, it would indicate a very great deviation in temperature at the adjacent FBG from that which is expected. This is unlikely given the requirement that the FBG locations be thermally coupled.
[0074] Where signals received from the optical fibre 200 lie in the shaded region on the wavelength axis, the sensor system has two choices. In one implementation, the system simply disregards the sensor readings and gives an error message indicating that the received light signal wavelength no longer indicates an unambiguous wavelength but instead indicates one of at least two temperatures depending on which of the FBGs are believed to reflected the signal. Alternatively, the analyser 402 can process the signal falling into the shaded ambiguous wavelength regions and see if the originating FBG (and therefore the correct temperature and location can be determined). This can be achieved in a number of ways.
[0075] First, the sensor system is configured to record the temperature and wavelength indications continuously over time. In this way, a received wavelength that falls in the shaded ambiguous portion of the wavelength axis can be compared against the received wavelengths for the immediately preceding time intervals. Assuming that historic values of the received wavelength originated in the unshaded region of the wavelength axis and then drifted into the shaded ambiguous region as the temperature changed, potentially ambiguous wavelength values can be resolved simply be inspection and comparison of previous values. This does however assume that the wavelengths are sampled often enough for successive values to be relatable to one another.
[0076] In a more simple configuration, the analyser may simply assume that wavelength values in the ambiguous region of the wavelength range belong to the unambiguous FBG wavelength range to which they are closest. This introduces more room for error, but does mean that the analysis and processing overhead of the sensor is less. In practice, using the wavelength values in the ambiguous regions of the wavelength axis will be desirable or unnecessary depending on the degree of overlap between the adjacent ranges. It will be appreciated that taking the wavelength value that is closest to the reference value occurs ordinarily when the wavelength that is received lies in the unambiguous range of wavelengths. Operating based on the closest wavelength therefore allows the system to disregard the distinction between the unambiguous and ambiguous ranges altogether.
[0077] Similarly, it will be appreciated that the dedicated range of wavelengths of FBG E may overlap by a small amount (for example, by an amount less than the overlap of the wavelength ranges allocated to FBGs A and B). Again, because it is assumed that the FBG locations are thermally coupled, even when the measured wavelength for FBG E lies in a range that is also allocated to FBG D (or FBG F) by analysing the wavelengths of light reflected by the other FBGS the temperature at FBG can be unambiguously determined.
[0078] The invention has been described with reference to example implementations, purely for the sake of illustration. The invention is not to be limited by these, as many modifications and variations would occur to the skilled person. The invention is to be understood from the claims that follow.
[0079] Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination. | The present invention relates to an optical fibre for a fibre optic sensor, comprising a first optical grating adapted to operate over a first range of wavelengths; and at least one set of further gratings adapted to operate over a second range of wavelengths, each grating being adapted to operate over a portion of the second range; wherein, each grating within said set has an operating range that partially overlaps with at least one other such grating operating range. The invention also extends to a sensor system, and method, using such an optical fibre. | 6 |
BACKGROUND
[0001] Technical Field
[0002] The present disclosure relates to the field of skin friendly silicone adhesive compositions and use of such compositions to secure medical appliances to mammalian body.
[0003] Background
[0004] There are medical conditions such as ostomy, pressure ulcer, fistula, chronic and acute wounds, highly exuding wounds, and fecal incontinence that require management of bodily fluids and waste. The management of such fluids and waste is critical in improving the condition such as related to wound healing, and maintaining a quality of life in the case of ostomy and fecal incontinence. Devices or appliances used to manage the above conditions are secured to the body using skin adhesives. Skin adhesives are also used to secure intra-venous or IV fluid lines, and insulin pumps to the body.
[0005] In the case of ostomy, the collection bag and adhesive wafer, either as separate components (referred to as “2-piece system”) or permanently jointed together (referred to as “1-piece system”) is attached to the peristomal skin through the adhesive wafer to manage stomal waste. It is challenging to securely attach an ostomy device or appliance to an abdominal stoma due to anatomical contour, skin folds or creases, irregular-shaped stomas, surgical scars, etc. While the adhesion of the adhesive has to be securely maintained while the device is in use, at the time of device change or removal, the adhesive should remove from the skin without causing trauma. This balance in secure adhesion while providing non-traumatic removal is very critical to the successful management of the medical condition. In order to protect the peristomal skin from stomal effluent, ostomates use adhesive discs such as cohesive seal or moldable ring, which form a dam or gasket around the peristomal skin. In some cases, these are convex-shaped to fit the profile of the peristomal contour of the abdomen. These adhesive discs are stretched to fit around the stoma, and pressed down to adhere to the skin. The ostomy wafer or bag is then placed on top of this adhesive gasket. The key properties for a useful adhesive disc or seal or ring for this purpose are its ability to stretch (or low elasticity) and maintain the shape, high tack and adhesion to skin, and good adhesion to the ostomy appliance.
[0006] In the case of wound care, dressings are used to manage the exudate and to promote wound healing. Wounds can occur in any part of the body, and depending on the location, it could be challenging to adhere a dressing to the wound. Similar situation arises in fistula, perianal skin management, fecal incontinence, where the anatomy of the body renders it difficult to securely adhere or attach devices to manage the exudate. In negative pressure wound therapy (NPWT) systems used for highly exuding wounds, a vacuum suction is applied to the dressing to displace the exudate from the wound bed and dressing. The securement of such dressings to the peri-wound area is critical to achieve the negative pressure gradient. An adhesive disc could be used to improve the securement of such devices around the wound or fistula.
[0007] There are several commercially available pressure sensitive adhesives (PSA) used as skin adhesives which are based on styrenic block copolymers, polyisobutylene, polyethylene, poly(ethylene-vinyl acetate) (EVA), acrylics, and polyurethane chemistries. PSAs are generally more viscoelastic than elastic. The balance of the elastic-viscoelastic properties renders them to be useful as skin adhesives and to secure devices to the body.
[0008] Most ostomy appliances are secured to the body using pressure sensitive adhesives loaded with absorbent fillers such as hydrocolloids or superabsorbents to manage the moisture and fluids that the adhesives come in contact with during the use of the appliances.
[0009] The use of silicone gel adhesives in ostomy is not common due their high elasticity and low tear strength. However, these gel adhesives have been used to secure wound dressings. The elastic nature of the gel adhesives allows them to retain their shape when stretched below their break point and allowed to relax. Also, the adhesion of these gel adhesives under stress is poor, which means when they are stretched to shape and bonded to skin, they relax back to their original shape resulting in delamination from skin. Silicone pressures sensitive adhesives, which are more viscoelastic, have been primarily used in transdermal drug delivery devices. Other chemistries, such as acrylic adhesives, have been widely used in intravenous (IV) tubing securement tapes and also in securing insulin pumps to the body. Due to the residual monomer in these compositions, and their aggressive adhesion, there is a preference for chemistries that do not contain residual monomers or do not affect skin health.
[0010] The present disclosure teaches compositions based on silicone gel adhesive compositions with a balance of elastic and viscoelastic properties of the adhesive, and with good adhesion to medical devices.
[0011] Prior art
[0012] U.S. Pat. No. 8,439,884 discloses a silicone elastomer double-sided tape to form a layer between an ostomy appliance and skin. The patent is silent about the adhesion properties of the adhesive to an ostomy appliance, which is critical to maintaining a liquid-tight seal, and the skin adhesion under moist conditions, which is normal in a per-stomal environment.
[0013] U.S. Pat. No. 7,842,752 discloses an skin adhesive composition based on a blend of silicone pressure sensitive adhesive (PSA), a silicone gel, and water absorbing fillers such as alginates, acrylates, cellulose, chitosan, etc.
[0014] U.S. Pat. No. 8,124,675 discloses a method to increase the MVTR of a silicone adhesive by the addition of sodium chloride.
[0015] U.S. Pat. No. 8,545,468 discloses a component comprising a silicone elastomer to protect the skin around a stoma in combination with a stoma appliance. The patent specifies the dry adhesion to skin but no mention is made of adhesion to skin under moist condition, and the adhesion of the component to the stoma appliance.
[0016] WO 2012/003028 A1 discloses the use of organic polyhydroxy compounds that do not affect the cure in silicone gel.
[0017] It is the objective of the present disclosure to provide a skin adhesive composition that can protect the skin, secure a device or appliance to the skin, and also maintain, and promote skin health.
SUMMARY
[0018] One objective of this disclosure is to provide a silicone adhesive composition to protect a region of a skin surface or peri-skin of a mammalian body.
[0019] Another objective is to secure medical appliances or devices to a peri-skin surface. Such devices include but not limited to catheter, intravenous feeding lines, securement devices, wound dressings, vac therapy devices, ostomy appliances, and the like.
[0020] The above objectives are wholly or partially met by devices, articles, appliances, intermediates, compounds, and methods according to the appended claims. Features and aspects are set forth in the appended claims, and in the following description in accordance with the present disclosure.
[0021] Accordingly, in one of the aspects, the present disclosure provides a method of forming a cured silicone adhesive composition to protect a region of a skin surface or peri-skin of a mammalian body, comprising the steps of a) mixing adhesive components comprising: 50-90 wt % of uncured silicone gel adhesive comprising a blend of a polydiorganosiloxane with at least one aliphatically unsaturated group, an organosiloxane with at least one silicone-hydride group, and an addition curing catalyst; 1-50 wt % of a non-silicone hydrophilic liquid additive; 0.1-10 wt % of a cohesive strengthening agent; b) coating the above adhesive mixture on a surface; and c) curing the coated adhesive mixture to form the cured adhesive composition on the surface. The surface could be a low surface energy surface, such as a fluorinated release coated liner, or a substrate to which the silicone can permanently bond and anchor to, such as a polymeric substrate. The cured silicone adhesive composition according to the present disclosure has a peel adhesion of 0.20-3.9 N/cm (0.5-10 N/in), 0.39-3.15 N/cm (1-8 N/in), 0.79-2.36 N/cm (2-6 N/in), 1.2-2.0 N/cm (3-5 N/in) or the like. The adhesive composition has a tack of 50-2000 grams, 100-1500 grams, 200-1000 grams, 300-500 grams, or the like.
[0022] In aspects, the hydrophilic liquid additive of the present disclosure is included in the range 1%-50%, 5-40%, 10-30%, or 15-20% by weight of the total adhesive composition. The hydrophilic liquid additive of the present disclosure reduces the elasticity of the cured silicone gel adhesive and increases the adhesion of the adhesive. The amount and type of hydrophilic liquid additive is typically chosen based on level of elastic-viscoelastic balance, tack and adhesion required of the cured adhesive. The hydrophilic liquid additive according to the present disclosure comprises any one or a combination of the group comprising: hydroxy acids, polyethylene glycol, polyethylene glycol-polypropylene glycol copolymers, glycerol ethoxylate, triacetin, hyaluronic acid and its derivatives, sodium hyaluronate, propylene glycol, polyglycerol, glycerol and its esters, sodium pyroglumatic acid, caprylyl glycol, propylene glycol, butylene glycol, sorbitol, algae extract, aloe vera, and glyceryl phosphate.
[0023] In aspects, the cohesive strengthening agent of the present disclosure comprises any one or a combination of the group comprising: fumed silica, fumed alumina, colloidal silica, nanoclays, silicates, silane treated organic polymers, polymeric metal oxides, non-polymeric metal oxides, and the like. The cohesive strengthening agent improves the tear strength and cohesive strength of the cured adhesive composition of the present disclosure. This agent is typically a particulate filler, which could also increase the viscosity of the uncured adhesive composition. The amount of cohesive agent is selected based on the improvement in strength required of the cured adhesive, and the viscosity levels manageable for processing the liquid uncured adhesive composition of the present disclosure. The cohesive strengthening agent is included in the range 0.1-10 wt %, 0.5-5%, 1.0-4%, or 1.5-3% by weight of the total adhesive composition. The preferred cohesive strengthening agent comprises fumed silica.
[0024] In aspects, the uncured silicone gel adhesive has a viscosity less than 150,000 mPa·s (or cP), less than 100,000 mPa·s (or cP), less than 10,000 mPa·s (or cP), or less than 2000 mPa·s (or cP).
[0025] In aspects, the silicone gel includes at least one polyorganosiloxane with at least one hydrophilic group selected from hydroxyl, sulfonyl, amino, acrylamido, amido, carboxylic acid or its salts, glyceryl, oxyethylene, and combinations thereof, in addition to the aliphatically unsaturated groups.
[0026] Optionally, the composition comprises trace-20 wt % of at least one siloxane resin. The siloxane resin may include at least one MQ resin. The MQ resin has at least one reactive group such as hydroxyl, alkoxy, hydride, or vinyl functionalities.
[0027] In other aspects, the present disclosure includes the use of a silicone adhesive to protect peri-anal, peri-stomal, peri-wound, surgical wound, or peri-fistula skin.
[0028] In another aspect, an ostomy adhesive to protect a region of a skin surface around a stoma is disclosed, which is formed by curing a mixture comprising: 50-90 wt % of uncured silicone gel adhesive comprising a blend of polydiorganosiloxane with at least one aliphatically unsaturated group, an organosiloxane with at least one silicone-hydride group, and an addition curing catalyst; 1-50 wt % of a non-silicone hydrophilic liquid additive; 0.1-10 wt % of a cohesive strengthening agent; and trace-20 wt % of at least one siloxane resin.
[0029] In another aspect, an ostomy adhesive seal comprising an ostomy adhesive is disclosed, which is formed by curing a mixture comprising: 50-90 wt % of uncured silicone gel adhesive comprising a blend of polydiorganosiloxane with at least one aliphatically unsaturated group, an organosiloxane with at least one silicone-hydride group, and an addition curing catalyst; 1-50 wt % of a non-silicone hydrophilic liquid additive; 0.1-10 wt % of a cohesive strengthening agent; wherein the seal has a top surface to adhere to an ostomy appliance, a bottom surface to adhere to a mammalian skin, and a through hole to fit around a stoma. The ostomy adhesive seal has a top surface to adhere to an ostomy appliance, a bottom surface to adhere to a mammalian skin, and a through hole to fit around the stoma. This comes in a pre-formed shape, which can be re-shaped to fit around a stoma. The pre-formed shape could be a disc, a rectangle, an oval, or the like. The through hole could also be a circle, an oval, or any other shape that matches a stoma opening. The ostomy adhesive seal wherein the bond between the ostomy appliance and the ostomy adhesive seal has a peel strength greater than 19.7 g/cm (50 g/in), or greater than 39.4 g/cm (100 g/in), or greater than 59.1 g/cm (150 g/in), or greater than 78.7 g/cm (200 g/in). In addition, the ostomy adhesive seal maintains the bond to peri-skin for greater than 8 hours, greater than 24 hours, greater than 48 hours, or greater than 72 hours.
[0030] In another aspect, an ostomy flange extender to secure an ostomy appliance to skin, comprising a substrate and an adhesive is disclosed, wherein the adhesive is formed by curing a mixture comprising: 50-90 wt % of uncured silicone gel adhesive comprising a blend of polydiorganosiloxane with at least one aliphatically unsaturated group, an organosiloxane with at least one silicone-hydride group, and an addition curing catalyst; 1-50 wt % of a non-silicone hydrophilic liquid additive; 0.1-10 wt % of a cohesive strengthening agent; wherein a surface of the cured adhesive is protected by a releasable liner. The substrate disclosed in the ostomy flange extender is a polymeric film selected from: polyolefins, polyvinyls, polyurethanes and polyurethane-ureas, polyvinyl chloride derivatives, polyacrylic and polyacrylates derivatives, polyacrylonitrile, polyesters, cellulosic films, polyimides, polyamides, polyether block amides, epoxy and phenolic plastics, polycarbonates, epoxy resins, fluorinated polymers, polyoxymethylenes, polyphenylene oxides, polysulfones, polyphenyl sulfide, silicones, or polysaccharide based materials.
[0031] In another aspect, an ostomy appliance comprising an ostomy adhesive wafer and a collection bag is disclosed, wherein the adhesive wafer comprises a substrate, and an adhesive, wherein the adhesive is formed by curing a mixture comprising: 50-90 wt % of uncured silicone gel adhesive comprising a blend of polydiorganosiloxane with at least one aliphatically unsaturated group, an organosiloxane with at least one silicone-hydride group, and an addition curing catalyst; 1-50 wt % of a non-silicone hydrophilic liquid additive; 0.1-10 wt % of a cohesive strengthening agent; wherein the wafer has a through hole to receive a stoma. The substrate is a polymeric film selected from: polyolefins, polyvinyls, polyurethanes and polyurethane-ureas, polyvinyl chloride derivatives, polyacrylic and polyacrylates derivatives, polyacrylonitrile, polyesters, cellulosic films, polyimides, polyamides, polyether block amides, epoxy and phenolic plastics, polycarbonates, epoxy resins, fluorinated polymers, polyoxymethylenes, polyphenylene oxides, polysulfones, polyphenyl sulfide, silicones, or a polysaccharide based materials.
[0032] Furthermore, in another aspect, an adhesive wound dressing to protect a region of skin surface around the wound is disclosed, comprising a fluid absorbing layer and an adhesive to secure the dressing to the skin surface, wherein the adhesive comprises: 50-90 wt % of uncured silicone gel adhesive comprising a blend of polydiorganosiloxane with at least one aliphatically unsaturated group, an organosiloxane with at least one silicone-hydride group, and an addition curing catalyst; 1-50 wt % of a non-silicone hydrophilic liquid additive; 0.1-10 wt % of a cohesive strengthening agent.
DETAILED DESCRIPTION
[0033] 100301 Particular embodiments of the present disclosure are described herein below; however, the disclosed embodiments are merely examples of the disclosure and may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure.
[0034] The cured silicone adhesive composition according to the present disclosure protects a region of a skin surface or peri-skin of a mammalian body and is able to secure appliances or devices to the body. The cured adhesive composition has a balance of elastic-viscoelastic properties, such that it can be shaped to size or fit around a stoma, wound, or fistula, and maintains the fit. The method of forming the cured composition comprises blending the uncured reactive components of silicone gel, a non-silicone hydrophilic liquid additive, a cohesive strengthening agent, and a silicone resin. The adhesive compositions according to the present disclosure provide a balance of elastic and viscoelastic behavior. This behavior can be evaluated by stretching the composition to a certain length below the tearing or breaking point, bonding the adhesive to a surface such as skin and observing the recovery to its original shape. The compositions of the present disclosure do not recover fully to their original length.
[0035] Silicone gel adhesives, sometimes referred to as tacky gels, have low peel adhesion, especially when under tension, which occurs, when a mass is stretched and bonded to skin. Also, the adhesion of such gel adhesives to skin, during perspiration or other sources of moisture, could be highly compromised. The addition of the hydrophilic liquid additive according to the present disclosure modifies the elasticity of the gel without compromising the adhesion and tack significantly. To further control the tack and adhesion, and the tear strength of the adhesive composition, a cohesive strengthening agent could be added. Another advantage of the present adhesive composition is the absence of residue on removal of the adhesive from skin surface. This is important for ostomy and wound applications.
[0036] In aspects, the silicone gel adhesive of the present disclosure can be cured by reacting at least one polyorganosiloxane with at least one aliphatically unsaturated group with at least one organosiloxane with at least one silicone-hydride (SiH) group in the presence of an addition curing catalyst. The preferred silicone gel adhesives are obtained by reacting an alkenyl-substituted polydiorganosiloxane, preferably a polydimethylsiloxane having silicon-bonded vinyl, allyl or hexenyl groups, and an organosiloxane containing silicon-bonded hydrogen atom and a catalyst for the reaction of the SiH groups with the Si-alkenyl (SiVi) groups, such as a platinum metal or its compounds or its complexes thereof. The ratio of SiVi:SiH can be 10:1 to 1:10. Preferred ratio of SiVi:SiH is 1:1. Altering the ratio of the reacting silicones from 1:1 ratio can change the adhesive properties of the gel. If a firmer, lower tack gel is required, the SiH component is higher than SiVi, and if a softer gel with higher tack is required, the SiVi component is higher than SiH. The silicone gel compositions can be cured at normal ambient temperatures, but curing times can be reduced by exposure to elevated temperatures, from about 40° C. to about 150° C. Non-limiting examples of such silicone gel adhesives are Soft Skin Adhesives SSA 7-9900, 7-9950 from Dow Corning Corporation, SILPURAN® 2130, SilGel® 612 from Wacker Chemicals. Hydrophilic group containing silicones, according to the present disclosure, may contain polar groups such as acid, amido, amino, sulfonyl, carboxyl, phosphate, phosphonate, etc., on the polydimethylsiloxane backbone. These groups could be present in an ionic form.
[0037] In aspects, the adhesive compositions according to the present disclosure comprise at least one liquid hydrophilic additive. The liquid additive of the present disclosure has some miscibility to the silicone gel fluids such than a stable emulsion is formed on complete mixing. Such miscible hydrophilic liquids have been found to not phase separate to the cured surface, which could result in a poor adhesive. The liquid hydrophilic additive can be incorporated into the silicone gel following conventional techniques of blending or mixing additives into silicone gels. For example, the hydrophilic liquid additive could be blended into either Part A or Part B of the silicone gel composition as a pre-mix, or at the meter mixer when the two parts of the gel are mixed together prior to curing the adhesive. It is desirable to obtain a smooth mixture of the adhesive components, either as a suspension or emulsion, such that the mixture is stable over a few minutes that could be required to processing the adhesive for curing reaction. The adhesive mixtures according to the present disclosure provide smooth mixtures suitable for coating, printing, or other processing techniques. In order to adjust the tack and adhesion level of the adhesive composition, the ratio of the two parts of the silicone gel may also be altered from the recommended ratio from the gel manufacturer.
[0038] The non-silicone hydrophilic liquid additive according to the present disclosure may at least be partially soluble or miscible in water. The viscosity of the hydrophilic liquid additive could be less than 100,000 mPa·s (or cP), less than 50,000 mPa·s (or cP), preferably less than 10,000 mPa·s (or cP), most preferably less than 1000 mPa·s (or cP). In cases where the liquid additive may retain moisture during storage, the additive could be dried in a desiccator, or in an oven, or other known drying methods prior to addition to the silicone gel. Non-limiting examples of such non-silicone liquid additives are hydroxy acids, polyethylene glycol, polyethylene glycol-polypropylene glycol copolymers, glycerol ethoxylate, triacetin, hyaluronic acid and its derivatives, sodium hyaluronate, propylene glycol, polyglycerol, glycerol and its esters, sodium pyroglumatic acid, caprylyl glycol, propylene glycol, butylene glycol, sorbitol, algae extract, aloe vera, glyceryl phosphate, and combinations thereof. Hydrophilic liquid additives according to the present disclosure yield cured silicone adhesive compositions that have good adhesion to mammalian skin.
[0039] In aspects, the adhesive in accordance with the present disclosure includes at least one cohesive strengthening agent. These agents improve the cohesive strength of the gel without compromising the adhesive properties significantly. Cohesive strengthening agents are known to reinforce the tensile and tear strength of silicone rubber. However, not all cohesive strengthening agents yield the same effect when an adhesive gel is required. The agents according to the present disclosure disperse well in the uncured adhesive matrix. The particle size of such agents according to the present disclosure is less than 100 microns, less than 50 microns, preferably less than 10 microns, most preferably, less than 1 micron. Non-limiting examples of cohesive strengthening agents of the present disclosure are silica, which could be fumed or precipitated silica such as AEROSIL® and SIPERNAT® grades, respectively, from Evonik Industries. The silica powders could be hydrophilic or hydrophobic, such as AEROSIL® 300, AEROSIL® 255, AEROSIL® R 812, AEROSIL® R 812 S, SIPERNAT® 120, SIPERNAT® 218, etc. Other non-limiting examples of cohesive strengthening agents include fumed alumina, colloidal silica, nanoclays, silicates, silane treated organic polymers, polymeric metal oxides, non-polymeric metal oxides, and the like. Since the cohesive strengthening agents are typically in particulate form with high surface area, dispersing the agents into the liquid silicone may require high shear mixing to ensure complete mixing and to break down agglomerates of the agent.
[0040] In aspects, the adhesive in accordance with the present disclosure may include at least one siloxane resin. Silicone resins are known to increase the adhesion of a silicone adhesive to skin or any substrate. They are also referred to as tackifiers for silicones. Silicone resins are silicone materials formed by branched, cage-like oligosiloxanes with the general formula of RnSiXmOy, where R is a non reactive substituent, usually Me or Ph, and X is a functional group H, OH, vinyl, or OR. These groups are further condensed in many applications, to give highly crosslinked, polysiloxane networks. Typical siloxane resins are MQ resins. MQ resins are three-dimensional network of M type and Q type silicon-oxygen structure. Non-limiting examples of commercially available MQ resins are MQ-RESIN POWDER 803 TF from Wacker Chemical Corporation; VQM-135, VQM-146, HQM-105, HQM-107, SQO-299, and SQD-255 from Gelest Inc., Prosil 9932, MQOH-7 from SiVance, LLC. The resins could have specific functionality such as hydroxyl, vinyl, hydride, and the like. Depending on the resin type and the molecular weight, they are either sold as powders or flakes, or as a solution in a solvent. The resins can be blended into the silicone gel Part A or Part B depending on the resin's functionality, prior to blending both parts together prior to curing reaction. Silicone resins are very expensive, and they tend to increase the tack significantly at the expense of peel adhesion. The resin amount in the adhesive composition of the present disclosure is from trace-20%, 0.5-15%, preferably 1-10%, most preferably 2-8% of the total adhesive composition.
[0041] The method of forming the cured silicone adhesive composition according to the present disclosure includes manufacturing processes such as web coating, printing, molding, etc. Those skilled in the art can appreciate that the catalyst used in addition cured silicones are very sensitive, and caution should taken to avoid any poisoning of the catalyst. Typically, the hydrophilic ingredients could be added to the non-catalyst part of the liquid reactive silicone in a two-part system. For one-part RTVs, this could require processing the composition immediately after adding all the ingredients. When curing the adhesive of the present disclosure on a substrate, primers, adhesion promoters, or other surface treatment methods could be employed to improve the adhesion of the adhesive to the substrate. When curing the adhesive of the present disclosure on a releasable liner, a suitable time and temperature condition besides the appropriate liner material has to be chosen. Such liner materials will not result in lock-up of the adhesive and can be removed from the liner for use.
EXAMPLES
[0042] Table 1 shows the examples according to the present disclosure. The silicone gel, Parts A and B, are weighed out in a plastic cup. The hydrophilic liquid additive and the other additives are then added to the silicone gel in the cup. The contents of the cup are mixed together by stirring with a stainless steel spatula. After thoroughly mixing the composition, a uniform coating is applied to a fluorinated release liner or a polyurethane (PU) film using a bird applicator from Byk-Chemie. The adhesive coated on release liner or PU film is cured in a convection oven at 130 C for 30 minutes. The cured adhesive surface is then protected with another fluorinated release liner after cooling to room temperature. For cohesive seal examples, the adhesive mixture is poured onto the fluorinated release liner and cured to form a disc of about 2 mm. The stretchability and elasticity of the composition is evaluated by gently stretching the cooled adhesive disc by hand.
[0043] Ingredients List:
[0044] MG7-9900—Dow Corning Corporation; SILPURAN® 2130, SilGel® 612—Wacker Chemical Corporation; MED-6340 and MED-6342—Nusil Inc.; Prosil 9932 resin solution—SiVance, LLC; MQOH-7 MQ resin—SiVance, LLC Glycerol—Sigma-Aldrich Chemical; Glycerol ethoxylate 441864 (MW ˜1000 g/mol)—Sigma Aldrich Chemical; Hyaluronic acid—Timeless Skincare; AEROSIL® 300 Pharma—Evonik Industries; Fumed silica 55505-100 g—Sigma-Aldrich Chemical.
[0000]
TABLE 1
Examples
Composition [wt %]
Con-
Con-
Con-
Con-
Ingredients
trol 1
1A
1B
trol 2
2A
trol 3
3A
3B
trol 4
4A
MG 7-9900
100
91
75
Part A + B (1:1)
SILPURAN 2130
100
91
57
Part A + B (1:1)
MED-6342
100
75
Part A + B (1:1)
MED-6340
Part A + B (1:1)
MED-634
Part A + B (1:1)
LR3003/10
Part A + B (1:1)
SilGel 612
100
91
Part A + B (1:1)
Polyethyl-
eneglycol 200
Glycerol
9
24
24
9
33
Glycerol ethoxylate
Hyaluronic acid
9
Prosil 9932
resin solution
MQOH-7 resin
AEROSIL
0.7
0.7
300 Pharma
Fumed silica
Properties
Mixed Gel viscosity
5100
NM
NM
8000
NM
1000
NM
NM
1000
NM
[manufacturer
mPa · s
mPa · s
mPa · s
mPa · s
data] cP or
(or cP)
(or cP)
(or cP)
(or cP)
m · Pa · s
Pre-cure mixture
Smooth
Smooth
Smooth
Smooth
Smooth
Smooth
Smooth
Smooth
Smooth
Smooth
appearance
*Dry adhesion
med
poor
med
low
low
high
very
very
low
med
or tack;
adh &
adh &
adh &
adh &
adh &
adh &
high
high
adh &
adh &
residue level
high tack;
tack;
high tack;
high tack;
tack;
tack;
adh &
adh &
high tack;
high tack;
no residue
residue
high
no residue
high
no residue
tack;
tack;
no residue
no residue
residue
residue
low
low
residue
residue
Recovery
100%
Medium
Medium
100%
Medium
100%
Medium
Medium
100%
Medium
on stretching
recovery
recovery;
recovery;
recovery
recovery;
recovery
recovery;
recovery;
recovery
recovery;
below tear/
breaks
med
med
breaks
breaks
breaks
break point
easily, poor
cohesive
cohesive
easily, poor
easily, poor
easily, poor
(~1.5 inch
cohesive
strength
strength
cohesive
cohesive
cohesive
disc cured
on release liner)
Composition [wt %]
Con-
Ingredients
4B
4C
4D
4E
4F
4G
4H
trol 5
5A
MG 7-9900
Part A + B (1:1)
SILPURAN 2130
Part A + B (1:1)
MED-6342
Part A + B (1:1)
MED-6340
Part A + B (1:1)
MED-634
100
91
Part A + B (1:1)
LR3003/10
Part A + B (1:1)
SilGel 612
91
77
75.5
71.4
67
83.2
83.2
Part A + B (1:1)
Polyethyl-
9
29
22.6
28.6
33
eneglycol 200
Glycerol
9
Glycerol ethoxylate
7.6
7.6
Hyaluronic acid
Prosil 9932
7.6
resin solution
MQOH-7 resin
7.6
AEROSIL
300 Pharma
Fumed silica
1.9
1.6
1.6
Properties
Mixed Gel viscosity
NM
NM
NM
NM
NM
NM
NM
15,300
NM
[manufacturer
mPa · s
data] cP or
(or cP)
m · Pa · s
Pre-cure mixture
Smooth
Smooth
Smooth
Marginally
Not smooth
Smooth
Smooth
Smooth
Smooth
appearance
smooth
snozzy
*Dry adhesion
med
high
high
high
phase
High
High
med
high
or tack;
adh &
adh &
adh &
adh &
separated;
adh &
adh &
adh &
adh &
residue level
high tack;
tack;
tack;
tack;
low adh &
tack;
tack;
high tack;
tack;
no residue
slight
slight
some phase
tack;
slight
no residue
no residue
no residue
residue
residue
separation
high
residue
residue
Recovery
Medium
Medium
Medium
Medium
NM
Medium
High
100%
Medium
on stretching
recovery;
recovery;
recovery;
recovery;
recovery;
recovery;
recovery
recovery;
below tear/
breaks
breaks
med
breaks
med
high
breaks
break point
easily, poor
easily, poor
cohesive
easily, poor
cohesive
cohesive
easily, poor
(~1.5 inch
cohesive
cohesive
strength;
cohesive
strength
strength
cohesive
disc cured
on release liner)
*Finger test: for dry, finger was pressed onto adhesive surface and withdrawn after few seconds:
indicates data missing or illegible when filed
[0045] It can be seen from Table 1 that the silicone gel adhesives without any hydrophilic liquid additive, samples marked “Control” 1-5, have acceptable dry adhesive properties. Since they are elastic gels, the recovery is 100%, which is not desirable for an ostomy application. The hydrophilic liquid additive improves adhesion in some silicone gels and affects adhesion in some. In addition, the hydrophilic additive leads to poor cohesive strength, as shown in examples 1A, 3A, 3B, 4A-C, 4E-F, and 5A under the Recovery on stretching section. When a cohesive strengthening agent such as silica is added in combination with the hydrophilic liquid additive, as shown in examples 1B, 2A, and 4D, a suitable cured adhesive composition with good adhesion, tack, cohesive strength and reduced recovery on stretching is obtained. Further, addition of an MQ resin to the silicone gel adhesive composition along with a liquid hydrophilic additive and cohesive strengthening agent, as shown in examples, 4G and 4H, results in a preferred adhesive composition with the right balance of properties.
[0046] Wear Testing:
[0047] Adhesive compositions shown in Table 2 were made by coating the adhesives at a thickness of 10 mils using a bird applicator on a PU film (Bioflex 130—2 mils thick from Scapa North America) and cured 130 C for 30 mins. About a 1×1.5 inch strip of tape with each adhesive was adhered to the dry abdominal skin of three people including the inventor. The tapes were worn for 24 hours during normal activities. Results are shown in Table 2.
[0000]
TABLE 2
Adhesive compositions for wear testing
Comparative
Comparative
Inventive
Comparative
Comparative
Inventive
Ingredients
Example 6
Example 7
Example 8
Example 9
Example 10
Example 11
Nusil
100%
90%
88.6%
0
0
MED-6345
(Part A + B)
SilGel 612
0
0
0
100%
90%
88.2%
(Part A + B)
Glycerol
0
10%
9.8%
0
10%
9.8%
Fumed
0
0
1.6%
0
0
2.0%
Silica
Wear test
Severe edge
Severe edge
No edge
Moderate
Moderate
No edge
results
lifting
lifting
lifting
edge lifting
edge lifting
lifting
and low
and medium
and high
and low
and medium
and high
adhesion on
adhesion on
adhesion on
adhesion on
adhesion on
adhesion on
removal
removal
removal
removal
removal
removal
[0048] Tape with Comparative Examples 6, 7, 9, and 10 showed moderate to sever edge lifting, while Examples 8 and 11, according to the present disclosure, showed no edge lifting. In addition, the peel strength of Examples of 8 and 11 were greater than Examples 7 and 10, which were greater than Examples 6 and 9. This clearly demonstrates the benefit of the present disclosure over prior art, and the neat gel adhesives. The combination of the liquid hydrophilic additive and fumed silica, provide a balance in tack, peel strength, and cohesive strength of the adhesive. | The present disclosure relates to the field of skin friendly silicone adhesive compositions and use of such compositions to secure medical appliances to mammalian body, and to protect and treat peri-skin surface. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
The application is the U.S. national phase of PCT/EP2014/058557, filed Apr. 28, 2014, which claims priority to European patent application No. 13166383.3, filed May 3, 2013, the contents of which are incorporated herein in their entirety.
FIELD OF INVENTION
The invention relates to a forming box for use in dry-forming a mat of fibrous material, said forming box comprising a housing with an open bottom for providing direct access of the fibres onto an underlying forming wire, and a vacuum box underneath said forming wire; at least one inlet for supplying fibre material into the inside of the housing; a number of spike rollers are provided in at least one row in the housing between the fibre inlet and the housing bottom.
BACKGROUND OF THE INVENTION
From WO 2005/044529, a device of such kind is known. The forming box of the apparatus described therein comprises a conveyer in the form of an endless belt screen adjacent to the row of spike rollers. As fibres enter the forming box they are sucked towards the forming wire and are distributed by the spike rollers, ensuring a relatively even distribution of fibrous material in the dry-formed mat. The conveyer ensures that no large lumps of fibrous material end up at the forming wire.
SUMMARY OF THE INVENTION
Considering the prior art described above, it is an object of the present invention to get a better control over the distribution of the fibrous material over the entire area of the forming wire within the forming box.
The object can be achieved by means of a forming box of the initially mentioned kind, wherein; a screen is provided adjacent said spike rollers, said screen comprising a plurality of slats, wherein each slat is rotatable.
By use of a screen comprising a plurality of slats it is possible to generate turbulence, which slows down the flow of fibres from the inlet to the forming wire and/or direct the fibrous material towards the desired area within the forming box. Here it obtains control over the distribution of the fibrous material in the mat. If the slats are not continuously rotating they can, for example, be positioned at a specific angle, hereby functioning as a fin to direct the fibrous material towards the desired area. Another alternative is to have the slats rotate any number of revolutions or part of a revolution and the change the direction and repeat the procedure. These different options on how to control the slats ensure the desired distribution of material in the mat for all types of fibrous material. Different laying formation of the fibres may, in this way, be achieved for forming fibre mats with a particular desired pattern.
Slat should be understood as a long and relatively thin, compared to its length, piece of material. The words lamella can also be used to denote the slats of the present invention. The slats can be rotated within the forming box along its longitudinal axis.
In an embodiment, the slats extend substantially perpendicular and/or parallel to the direction of the inlet. Hereby, the turbulence generated by the screen can be adapted to compensate for the irregularities in the distribution of the fibrous material when entering through the inlet.
Advantageously, all the slats are rotated in the same or different direction. Depending on the material used in the forming box it may be desired that the slats rotate in the same direction, alternatively, some of the slats may rotate in the opposite direction, a further alternative is that some of the slats do not rotate, but rather are used as fins to direct fibrous material to the desired area of the forming wire. The rotation is preferably continuous; however, a non-continuous rotation of one or more of the slats can be used.
In an embodiment, the slats are pivoted individually. To a greater extent, this provides more control over the distribution of the fibrous material, both when suspended inside the forming box and when it settles on the forming wire.
In an embodiment, the slats are provided with a non-symmetric cross-section. This can be done in order to enhance the turbulence and/or directing the fibrous material in the forming box. Further, the turbulence generated by the slats can ensure that the slats are self-cleaning; so the turbulence will remove fibrous material stuck on the slats.
In an embodiment, the forming box comprises at least two rows of spike rollers and at least two screens adjacent a row of spikes rollers, wherein each screen comprises a plurality of slats, wherein each slat is rotatable. Having more than one set of row spike rollers and screens provide extra disintegration of fibres or lumps of fibres by the spike rollers, which may be advantageous for some applications.
Preferably, the slats are provided with a predetermined mutual distance, said distance being adjustable. Hereby a further enhancement of the control of the distribution of the fibrous material may be achieved.
In an embodiment, a separate material inlet is provided above the fibre inlet, and a granulate material or a second type of fibre material is supplied through said separate material inlet, so this second material supply is mixed with the fibres supplied through the fibre inlet. Hereby a mat comprising different types of fibre material can be produced. It is advisable to transport different types of fibre material at different air speeds, and in order for the fibres to be able to mix, it is advantageous to have a separate inlet for each of the fibrous materials used.
In an embodiment, the rotation and/or pivoting of the slats are controlled by the properties of the mat exiting the forming box; preferably the properties are determined by use of a scanner. Hereby the quality control of the mat made of fibrous material can be made in situ and the slats can be regulated in order to ensure a high quality of the mats.
In an embodiment, the slats are adapted to neutralize a build-up of static electricity on the slats. Static electricity can be a problem during dry-forming of mats, especially in dry environments. In order to neutralize the build-up of static electricity on the slats the slats can be made of a material or coated with a material so that build-up of static electricity is less likely or difficult to occur and/or the slats can be electrically connected to a discharge device and/or ground.
The invention further regards a method for the dry-forming of a mat of fibrous material, comprising the steps of; blowing fibrous material into a forming box, having an open bottom positioned over a forming wire to form a mat of fibres on the forming wire, the forming box having a plurality of fibre-separating spike rollers for breaking apart clumps of fibres; providing a screen of slats adjacent the spike rollers, and conditioning the fibres inside the housing by rotating one or more of the slats.
The conditioning of the fibres is performed by the rotation of the slats, and slows the flow of the fibres from the inlet to the forming wire. The result is a controllable cross-sectional distribution of fibres in the forming box. Hereby different formations of the fibres on the forming wire may be achieved.
Preferably, the conditioning of the fibres includes the step of stirring up the fibres inside the housing. Hereby the fibres are distributed within the forming box. The stirring up of the fibres can be done by generating turbulence in the air flow by rotating the slats.
In an embodiment, the conditioning involves directing the fibres towards the bottom of the forming box. Hereby, the fibrous material, forming the mat, can be distributed in the desired manner.
Advantageously, the one of more of the slats are non-rotating. The slats can then be used to passively direct the fibrous material towards the desired area of the forming wire.
In an embodiment, the non-rotating slats are angled to direct the fibres towards the forming wire.
In an embodiment, a separate material inlet is provided above the fibre inlet, and that a granulate material or a second type of fibre material is supplied through said separate material inlet, so this second material supply is mixed with the fibres supplied through the fibre inlet. Hereby, a mat comprising different types of fibre material can be produced. Preferably, the supplied granulate is selected from a group of materials including: vermiculite, rubber, plastic, glass fibre or mineral wool fibres.
Preferably, the supplied granulate is a metallic granulate or metallic fibre, such as aluminium, brass or steel.
It is to be understood, that the method can be adapted to comprise any of the preferred embodiments mentioned above for the forming box.
DESCRIPTION OF THE DRAWINGS
The invention will in the following be described in greater detail with reference to the accompanying drawings:
FIG. 1 a schematic side view of a forming box according to an embodiment of the invention;
FIG. 2 a schematic top view of a forming box according to an embodiment of the invention;
FIG. 3 a schematic side view of an arrangement of spike rollers and slats;
FIG. 4 a schematic side view of a forming box according to an embodiment of the invention;
FIG. 5 a schematic cross-sectional view of different types of slats.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 a forming box according to a first embodiment of the invention is shown. The forming box comprises a housing 1 into which fibres 3 are supplied from an inlet 2 . The forming box is positioned above a forming wire 4 onto which the fibres 3 are air laid due to a vacuum box 5 underneath the forming wire 4 to form a fibre mat 6 in a dry forming process. In FIG. 1 , the forming box is shown in a cross-sectional view with the interior elements visible in the housing.
The fibre mat 6 may be made from or at least include natural fibres, such as cellulose fibres, animal hair, fibres from flax, hemp, jute, ramie, sisal, cotton, kapok, glass, stone, old newsprint, elephant grass, sphagnum, seaweed, palm fibres or the like. These fibres have a certain insulating capacity which may be useful in many applications. The fibreboard 6 may also be made from or at least include a portion of synthetic fibres, such as polyamide, polyester, polyacrylic, polypropylene, bicomponent or vermiculite fibres or the like as well as any kind of granular material.
Fibreboards with such synthetic fibres may be used for providing the fibre product with certain properties, e. g. absorbent products. Moreover, the fibres may be pretreated with a fire retardant or a fire retardant may be supplied directly in the fibre mixture which is blown into the forming box.
The fibres 3 are blown into the housing 1 of the forming box via the inlet 2 . Inside the forming box a number of spike rollers 7 are provided in one or more rows, e. g. four rows of spike rollers 71 , 72 , 73 , 74 as shown in FIG. 1 . In the housing, two screens 81 , 82 having a number of slats 8 arranged in rows, can be seen. These screens 81 , 82 are arranged in between and adjacent to two rows of spike rollers, in two sections 91 , 92 . In the first section 91 the rows of spike rollers 71 are situated adjacent and at a higher level than the screen 81 . On the opposite side of the screen 81 a row of spike rollers 72 is present at a lower level. The lower section 92 is similar to the upper section 91 but arranges at a different level in the housing 1 .
The screens 81 , 82 has slats 8 that are rotatable, in the present embodiment they have a rectangular cross section and are rotated continuously in order to condition the fibres 3 by way of turbulence generated from the rotation. The fibres 3 may be supplied into the housing 1 in lumps. The spike rollers 7 then disintegrate or shred the lumps of fibres 3 in order to ensure that the fibres are no larger than a desired size. In the upper section 91 the fibres pass the spike rollers 71 in the first row 71 , subsequently the screen 81 and then the second row of spike rollers 72 as the fibres are sucked downwards in the housing 1 . The fibres 3 then pass the lower section 92 in similar fashion as the upper section 91 . It is not necessary to have two sections 91 , 92 as shown in FIG. 1 . However, it is preferred in order to ensure that all the fibre 3 lumps are shredded and distributed as desired, rather than just sucked towards the forming wire 5 which can result in an uncontrollable and uneven formation of mat on the forming wire 5 .
The continuous rotation ensures that the fibres 3 adjacent to the screen 81 and 82 are stirred up and mixed, ensuring a uniform distribution of the fibres 3 . Further, the generated turbulence has the advantage that it ensures that the slats 8 are kept relatively free of fibrous material. In other words, the slats are self-cleaning because there will only be a minor amount of build-up of fibre material before the turbulence will suspend it again. This is advantageous as it prolongs the time needed between cleaning of the inside of the forming box.
FIG. 2 shows a top view of a forming box according to an embodiment of the invention. It has an inlet 2 , which supplies fibres 3 (not shown in FIG. 2 ) to the housing 1 . The forming wire 4 enters the housing 1 and exits the housing with the mat 6 formed on it. FIG. 2 only shows one screen with slats 8 in the housing 1 , it is to be understood that the embodiment also has spike rollers 7 within the housing 1 , as shown in FIG. 1 . The slats 8 are arranged on a rack 10 and perpendicular to the moving direction of the forming wire 4 . The slats 8 can have any angle, however, it is preferred that it is parallel or perpendicular to the moving direction of the forming wire 4 or any other angle. The rack 10 can be arranged so the slats 8 can be moved up, down or sideways so the distance between two slats 8 can be changed and/or the slats 8 in one screen can have different elevated positions than in another. The slats 8 are mounted on the rack 10 in a way so they can rotate. On the figures no rotation means are shown, however, it is known for the skilled person how to get a slat to rotate, this can be done by use of an motor, a step motor can be used if a specific angle for the slat is desired, however, other possibilities are available. The rack 10 is preferably placed outside the housing 1 so the bearing of the slats 8 are kept out of contact with the fibrous material which can harm the bearings.
The inlet 2 is located at a higher position than the screen of slats, further, there is row of spike rollers (not shown) at a higher position than the screen of slats 8 . The vacuum box 5 ensures that there is an air flow from the inlet 2 to the vacuum box 5 so the fibrous material, which enters the housing through the inlet 2 , gets sucked towards the forming wire 4 and there form a mat 6 of fibrous material. The fibrous material 3 is shredded by the spike rollers and pas the screen of slats where it is slowed down and mixed due to the turbulence generated by the screen. Hereby a relatively uniform distribution of the fibrous material in the volume below the screen is achieved.
If a uniform fibre mat is to be produced, it is desirable that; firstly, lumps of fibrous material that enter through the inlet are shredded, this is ensured by the spike rollers; secondly, that the shredded fibrous material containing no large lumps are distributed evenly within the housing 1 so it gets uniformly distributed on the forming wire 3 . There may be use of a plurality of sections comprising spike rollers and a screen of slats in order to ensure that all the lumps of fibrous material has been fragmented and distributed evenly. It may be advantageous to direct some of the fibrous material to certain spaces within the housing, in order to compensate for the effects on the flow from the walls or other objects within the housing 1 .
If a non-uniform fibre mats are to be produced, the forming wire may have a non-constant speed and/or the screen of slats can be used to direct the fibrous material towards a specific area of the forming wire 4 .
In FIG. 3 a schematic view of a different setup of spike rollers and slats is shown. It discloses a section similar to the sections 91 shown in FIG. 1 having a screen of slats 8 between two rows of spike rollers 71 , 72 further, an additional screen of slats 83 is arranged under the section 91 . The additional screen has slats 83 with a cross-section similar to a fin so that the fibrous material can be distributed by positioning them in a specific angle. The slats 8 in the screen 81 have a rectangular cross section and are pivotally mounted on an axle 11 so they can rotate as illustrated by the arrows 12 . The slats can also be shifted horizontally as illustrated by the arrow 13 . Thereby, a large degree of freedom in adjusting the screen 81 is obtained. The screen can be adjusted to perform optimally for any fibrous material. The slats 83 can be pivoted around the axle 14 and can thereby direct the suspended fibrous material towards the desired area of the forming wire.
FIG. 4 discloses a cross sectional view of another embodiment of the invention. The forming box comprises a housing 1 with an inlet 2 and a vacuum box 5 . The forming wire 4 enters the housing 1 and the fibrous material is sucked towards it, and a fibre mat is dry formed in it. The housing has a first row of spike rollers 71 and a second row of spike rollers in between the two, a screen of slats 81 is arranged. The screen 81 is arranged adjacent to the spike roller rows 71 and 72 and forms a section similar to the one described above. At a lower level in the housing 1 a third row of spike rollers 75 is arranged. Adjacent hereto there is an additional screen of slats 84 . This screen of slats has the profile of a fin which is used to direct the flow of fibrous material.
The skilled person will realise that there are a plurality of possibilities for combining the number, position and/or revolution speed of spike rollers and number, position, rotational patterns and/or angular position of the slats.
The embodiment in FIG. 4 further has a roller adapted to press the fibre mat 6 hereby ensuring an even height of the fibre mat 6 .
FIG. 5 discloses a cross sectional view of different slats 8 . They are pivotally mounted on an axle 11 . The Skilled person will acknowledge that the slats can be designed with the axle at a different place whereby the rotational pattern is changed. The slat on FIG. 5 a has the form of a fin and is preferably used to direct airflow where the fibrous material is suspended. On FIGS. 5 b and 5 f a square and rectangular slat is shown, respectively they are preferably used to generate turbulence. The cross section in FIG. 5 c is oval and in FIGS. 5 d and 5 e it is a square with two or four sides, respectively, has the form of a circular arc. The cross section can also be triangular.
In the above-described embodiments, the forming box is shown with one inlet 2 . However, it is realised that multiple inlets may be provided, e. g. for supplying different types of fibres to the forming box. The spike rollers 7 and indeed the slats 8 will then assist in mixing the fibres inside the forming box.
In an embodiment, a granulate or another type of fibre may be supplied into the forming box above the fibre inlet 2 and mixed with the fibres adjacent the inlet opening inside the forming box. Such granulate is supplied separately to the forming box since it must be transported at a separate (higher) airflow velocity. This granulate may include vermiculite, rubber, plastic, glass fibre, rock wool, etc. The granulate may also include metal fibres, such as aluminium or brass, steel, etc.
The present invention is described above with reference to some preferred embodiments. However, it is realised that many variants and equivalents may be provided without departing from the scope of the invention, as defined in the accompanying claims. | The invention regards a forming box for use in dry-forming a mat of fibrous material, said forming box comprising a housing with an open bottom for providing direct access of the fibers onto an underlying forming wire and a vacuum box underneath said forming wire, at least one inlet for supplying fiber material into the inside of the housing, a number of spike rollers are provided in at least one row in the housing between the fiber inlet and the housing bottom, wherein a screen is provided adjacent said spike rollers, said screen comprising a plurality of slats, wherein each slat is rotatable. | 3 |
FIELD OF THE INVENTION
The present claimed invention relates generally to the field of wireless communication systems. More particularly, the present claimed invention relates to the remote operation and maintenance of a packet based wireless base station which interfaces with Call Agents using a wireless signaling protocol.
BACKGROUND ART
Local area networks such as Ethernet are well known. Most local area networks are wired, so that each station is connected directly or indirectly to all other stations by cabling or wires, thus providing full connectivity between all stations. Such local area networks avoid collisions and achieve efficient use of the communications channel by well known carrier sensing and collision avoidance schemes. Such schemes are typically not suitable for wireless networks. Communication systems that utilize coded communication signals are also well known in the art. One such system is a code division multiple access (CDMA) cellular communication system such as set forth in the Telecommunications Industry Association/Electronic Industries Association International Standard (TIA/EIA IS-95), hereinafter referred to as IS-95.
FIG. 1 is an illustration of a conventional prior art CDMA system. In the system shown in FIG. 1 , base stations 110 and 120 are connected to a base station controller 130 and a mobile switching controller 140 which is in turn connected to the public switched telephone network (PSTN) 150 and a public land mobile network (PLMN) 160 using known techniques.
In the system shown in FIG. 1 , when a communication unit (CU) 105 , 107 , or 106 initiates a call sequence to either one of the base stations 110 and 120 within a coverage area, an end-to-end connection is established between the respective base stations, the base station controller 130 and the MSC 140 using known CDMA call setup techniques. The base stations 110 and 120 typically communicate with the BSC 130 and the MSC 140 via communication links, such as a T1 connection. Base stations 110 and 120 typically have antennas to define the coverage area within which either base stations primarily accommodate the communication units.
With the proliferation of wireless devices in the office and school environment, the communication system shown in FIG. 1 can be very expensive if implemented in an office or in-building environment. The system in FIG. 1 also has the inherent problem of wireless voice and data signal quality degradation if implemented in an in-building environment.
To alleviate the problems of the system shown in FIG. 1 and with the advent of enterprise based wireless networks, some prior art CDMA systems implement the system shown in FIG. 2 . FIG. 2 includes a plurality of clients, a plurality of base transceiver stations 201 , 202 , 203 , and a set of base station controllers 110 and 120 , which are coupled to O&M sever 210 and a mobile switching center 140 . O&M server 210 is coupled to O&M clients 215 and 220 . In the system illustrated in FIG. 2 , a wireless base station is connected to existing ethernet network infrastructure to enable the CDMA system to utilize existing internet protocol techniques to allow communication between wireless devices connected to the ethernet network.
The system in FIG. 2 utilizes a combination of wireless signaling protocol and media gateway protocol to allow wireless call handling and other multi-media data transmission. A wireless signaling protocol is necessary in order to handle mobile terminals. Communications on the LAN is implemented between requestors of information (clients) and providers of the information (servers) via a communication protocol such as a Transmission Control Protocol (TCP).
Despite the robustness of the system in FIG. 2 in an in-building wireless environment, there are some disadvantages which characterize such systems and other prior art CDMA systems when it comes to the maintenance and operation of such systems.
First, in these conventional systems such as that in FIG. 2 , the method of operating and maintaining of the wireless network is by connecting an operation and maintenance server(s) to the wireless network using either SS7, X.25 or other LAN connections. In these systems, a operation and maintenance center is equipped with operation and maintenance servers with associated operation and maintenance tools. Access to the servers is limited to operations and maintenance client systems which are physically connected to the network.
Due to the mobility constraints of such systems, a technician is required to be stationed in the O&M center to physically monitor the operation of the network. With the proliferation and advances of the internet and intranets, some O&M clients can be remotely connected to the O&M servers to handle the required network management of these systems. As accessibility to the internet from remote locations continues to become more widely available and convenient, utilizing the internet to perform such tasks such as remote system operation and maintenance becomes increasingly desirable. Some methods have been developed in the prior art to allow for such remote access management. However, such methods require access to the O&M server via a Call Agent connected to the network. Processing O&M server calls through the Call Agent can be time consuming, cumbersome and take Call Agent resources away from conventional mobile devices accessing the network.
Thus, it is desirable to have a system and a method for handling remote access requests to a CDMA wireless enterprise system for system operation and maintenance management. There is a further desire to have a system for transmitting CDMA calls including voice and data over a communication pathway with a higher bandwidth such as the internet. It is further desirable to have a CDMA system that handles the transmission of calls, especially data calls, without the inherent difficulties of using a variety of transmission protocols for the same call. A need further exists for improved and less costly systems which improve efficiency and the transmission rate and time of calls between a mobile unit and a base station and between base stations and a base station controller and between adjacent base stations.
SUMMARY OF INVENTION
The present invention is directed to a system and a method for providing an enterprise in-building or campus-wide IP based code division multiple access (CDMA) wireless system. The present invention is capable of handling both voice and data transmission over an internet protocol local access network within the CDMA system without the inherent delays and signal quality degradation encountered by conventional CDMA systems. The present invention further provides a system and method of providing a remote wireless operation and system maintenance of a wireless enterprise system by utilizing existing internet protocol and communication language.
Embodiments of the invention include a system for a wireless base station which couples to existing local area networks (LAN) within an enterprise to provide remote access to a mobile wireless client which may be used to perform routine system operation and maintenance management. The base station further includes call processing determination logic which handles the decision of directing mobile calls received by the base station to either a call agent attached to the LAN or a operation and maintenance server which is also attached to the LAN.
In one embodiment of the present invention the base station and operation and maintenance server negotiate to set a predefined number to allow a mobile operation and maintenance client to call into the enterprise system. The mobile operation and maintenance call number is also dynamically negotiated and set by the base station and the operation and maintenance server in order to allow multiple operation and maintenance clients to call into the enterprise system.
In order to handle mobile operation and maintenance clients, the operation and maintenance server includes call processing logic which enables the server to perform call agent like functions. This allows the mobile operation and maintenance client to call into the enterprise system and allow a technician to perform typical operations and maintenance functions without having to be physically tied to the operation and maintenance server. The ability to perform call agent like functions by the operation and maintenance server is not available in the prior art.
The present invention further provides an implementation advantage over the prior art by allowing inter network communication between the wireless office communication system of the present invention and other mobile networks on the public land mobile network. The inter-networking communication of the present invention is implemented over an IP LAN using the ethernet transport protocol of UDP/IP or TCP/IP transport protocol via an ethernet interface to the ethernet back-bone of the system. The use of the ethernet interface is less costly than the prior art and further allows easy and flexible connectivity to existing in-office, building or campus networks.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiments which are illustrated in the various drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of this specification, illustrates embodiments of the invention and, together with the description, serve to explain the principles of the invention:
Prior Art FIG. 1 is a block diagram of a conventional code division multiplex access (CDMA) system;
FIG. 2 is a block diagram of an implementation of a prior art enterprise CDMA system;
FIG. 3 is a block diagram of a remote wireless CDMA operation and maintenance system of the present invention;
FIG. 4 is a block diagram of an embodiment of a wireless base station and a operation and maintenance server of the present invention; and
FIG. 5 is a block diagram of an embodiment of the call message flow from a wireless operation and maintenance client to a operation and maintenance server of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in conjunction with the preferred embodiments, it will be understood that they are not intended to limit the invention to these embodiments.
On the contrary, the invention is intended to cover alternatives, modifications and equivalents, which may be included within the spirit and scope of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one of ordinary skill in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, components, and circuits have not been described in detail as not to unnecessarily obscure aspects of the present invention.
The invention is directed to a system, an architecture, subsystem and method to manage a wireless CDMA data communication in a way superior to the prior art. In accordance with an aspect of the invention, a base station allows CDMA call coverage within a building without requiring a dedicated and a lengthy end-to-end transmission.
In the following detailed description of the present invention, a system and method for a wireless internet protocol based communication system is described. Numerous specific details are not set forth in order to provide a thorough understanding of the present invention. However, it will be recognized by one skilled in the art that the present invention may be practiced without these specific details or with equivalents thereof.
Generally, an aspect of the invention encompasses providing an integrated wireless internet protocol based in-building or campus-wide CDMA communication system which provides a wide range of voice, data, video and other services in conjunction with a private branch exchange interfaced to the Public Switched Telephone Network (PSTN) and the Public Land Mobile Network (PLMN). The invention can be more fully described with reference to FIGS. 3 through 5 .
FIG. 3 is a functional illustration of the wireless system of the present invention. Wireless System 300 (WS) comprises, one or more mobile or wireless communication units 303 , a plurality of enterprise wireless base stations (WIBS) 310 – 318 , a Call Agent 320 coupled to an ethernet backbone of the LAN 301 , a public switch telephone network gateway 330 (PSTN) which further couples to the Public Switch Telephone Network 324 , an internet/intranet gateway 340 which couples to the internet 342 and an enterprise intranet 343 and an operations and maintenance server 350 .
In the system illustrated in FIG. 3 , a remote access wireless operation and maintenance client 305 couples to WS 300 via any of the wireless base stations to provide a operation and maintenance management technician access to the operation and maintenance server 350 . The maintenance technician may access the WS 300 by using well known internet browsers to login into the enterprise system.
In order to enable a wireless operation and maintenance management functions, wireless client software which is running on a mobile terminal 305 establishes a data link (either an Asynchronous or Packet date link) to the operations and maintenance server 350 via one of base stations 310 – 318 . In the present invention mobile terminal unit 305 may be a personal digital assistant (PDA) with wireless connectivity, a notebook computer connected to a mobile phone, a web-enable mobile phone or any wireless computer system.
To establish the data link to the operations and maintenance server 350 , mobile unit 305 transmits an access request to either of the WIBS 310 – 318 . The access request is in the form of a unique operations identification number which is predetermined and pre-negotiated between the operations and maintenance server 350 and the base station. The operation identification number is a numerical digit of a predetermined length which may be dynamically updated between the base stations and the operations and maintenance server as part of the operation and maintenance server's managed information base.
Anyone of base stations 310 – 318 which receives an O&M server call request from mobile unit 305 initiates a data call setup procedure with the operations and maintenance server 350 rather than with the Call Agent 320 . After a data call has been established between the mobile unit 305 and server 350 , a point to point protocol session is established between terminal 305 and server 350 . The Point-to-Point Protocol session enables terminal 305 to establish a data link connection to the O&M server to allow communication (e.g. the transfer of operational commands and instructions) between the wireless O&M client and the server 350 . The Point-to-Point Protocol provides data-link connection and typically has the IP protocol running on top of it.
Once the Point-to-Point Protocol session is established, terminal 305 is able to initiate and establish a HTTP session to server 350 to access to the maintenance and operation tools in server 350 MIB and function as if the operations and maintenance client running on terminal 305 is directly connected to LAN 301 . Thus, all operations typically performed by client 352 is now performed by client 305 .
Referring now to FIG. 4 , a block diagram of an embodiment of the WIBS 310 and O&M server 350 is provided. As shown in FIG. 4 , WIBS 310 includes call processing logic unit 410 , O&M call processing logic 420 and O&M access control and logic unit 430 . Call processing logic 410 is coupled to receive non-O&M wireless call requests intended for Call Agent 320 ( FIG. 3 ) via WIBS 310 for typical CDMA wireless call functions.
Call processing logic 410 performs call processing functions which typically would have been performed by Call Agent 320 . By having call processing logic 410 in the O&M server, the O&M server ensures routing of non-operation and maintenance calls to Call Agent 320 .
O&M call processing logic 420 is coupled to receive O&M calls from O&M wireless clients to access the O&M server 350 . In the preferred embodiment O&M call processing logic is able to determine whether to access the O&M server 350 by using a unique call identification number which is provided by Call access control unit 430 . Call access control unit 430 is coupled to negotiate with the O&M server 350 unique call identification numbers which would allow remote O&M wireless clients to directly access the O&M server 350 . In the preferred embodiment, the call identification number is a alphanumeric number (e.g., #3333) which is pre-determined between the O&M server and the base station and is stored in the O&M server's managed information base.
In the present invention, call access control logic 430 is capable of dynamically negotiating with the O&M server 350 to set an access number which only allows remote access to the O&M server 350 by remote wireless O&M client systems. Control logic 430 is also capable of negotiating a pre-determined access code which is stored in WIBS 310 to allow WIBS 310 to determine whether an incoming call request is to be sent to the O&M server 350 or to Call Agent 320 .
Still referring to FIG. 4 , O&M server 350 includes access control logic unit 440 , call processing logic unit 450 and O&M function logic unit 460 . Access control logic unit 440 performs similar function as access control logic unit 430 . O&M call processing logic 450 negotiates with WIBS 310 to set dynamically or statically the access code for wireless O&M clients to access the O&M server 350 .
Call processing logic 450 is coupled to provide call processing functions to the O&M server 350 . Having a call processing logic in the O&M server is a novel way of having the O&M server provide call agent like functions which the prior art does not provide. Processing logic unit 450 also provides the O&M server 350 call processing capabilities to ensure that O&M client calls do not compete with other conventional mobile calls to the enterprise system.
Calls processed by call processing logic 450 are handed-off to O&M server functions logic 460 which grants remote access processing of O&M functions and tools to the O&M remote client. O&M server functions logic 460 also provides other typical O&M functions for O&M clients physically connected to the enterprise system.
Referring now to FIG. 5 is a sequence flow diagram of the wireless operation and maintenance operation of the present invention. The operation of present invention is initiated by a mobile operation and maintenance client issuing a connect request for a data call for wireless operation and maintenance number via request signal 510 to WIBS 310 .
In the preferred embodiment, the request number may be a predetermined alphanumeric number (e.g., #3333). The mobile terminal originates a data call service option and calls the requested number by transmitting the data call request via signal 520 to the WIBS 310 . When WIBS 310 detects the wireless operation and maintenance request signal it sends a connection management service request to the operation and maintenance server via request signal 530 .
The operation and maintenance server 350 responds to the WIBS 310 request by establishing a data connection to the mobile terminal on a dedicated traffic channel and transmitting an acknowledgment signal via signal 540 to the WIBS 310 . In response to the traffic channel signal from the operation and maintenance server, the WIBS establishes a data connection to the mobile terminal of the traffic channel at step 550 of FIG. 5 to enable the mobile terminal to communicate to the operation and maintenance server.
When the mobile terminal receives signal 555 , mobile terminal establishes a Point-to-Point Protocol connection (step 560 ) with the operation and maintenance server to begin communications with the maintenance and operation tools. To communicate with the operation and maintenance server, the operation and maintenance running on the mobile terminal establishes a web connection with server via signal 570 and send operation and maintenance commands using HTML or other similar internet communication language at step 580 of FIG. 5 .
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications 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. | A wireless office communication system including a multi-protocol wireless internet base station (WIBS) encompassing a base station controller, a mobile switch controller and an ethernet interface module for coupling the WIBS to an existing internet protocol (IP) based network. The interface module provides for coupling the WIBS to an ethernet back-bone, a mobile communication unit and a public switch telephone network (PSTN). In one embodiment of the invention, a maintenance and operation server is coupled to the ethernet back-bone to allow a technician to remotely call into the enterprise system from a mobile system such as a lap-top computer or a personal digital assistant (PDA) to perform typical system operations and maintenance functions via the internet. | 7 |
FIELD OF THE INVENTION
[0001] The invention relates to the field of in-building radio communication coverage enhancement. Specifically, the invention provides a solution to maintain radio communication coverage inside a facility when the primary radio transmission tower providing the radio communication signals to the in-building system fails or is taken out of operation for maintenance or service. The invention will detect that the signals from the primary transmission tower are not viable and automatically connect radio communication signals from an alternate transmission tower to the in-building system electronics and signal distribution system.
BACKGROUND OF THE INVENTION
[0002] Wireless communication devices, such as cell phones and two-way radios, are becoming ever more popular. Such devices typically receive and transmit radio frequency (RF)signals from and to remote RF signal transmission towers, such as cell towers. While RF signals are capable of penetrating solid objects, the strength and quality of those signals degrade as more barriers are present between the transmission tower and the wireless communication device. Signal degradation is especially acute within structures, such as office buildings or factories, which offer multiple barriers between the transmission tower and the wireless communication device.
[0003] In-building radio frequency communications systems have been developed to improve performance of wireless communication devices within structures. These systems typically use a strategically located and directed antenna, which typically is located on the exterior of the structure (roof or side wall), providing a communications link with a RF signal transmission tower. The directed antenna is focused at a specific RF signal transmission tower (primary RF signal donor site) in an effort to maximize desired signal levels from the donor site to the in-building system. In addition, the directed antenna will minimize the level of non-desired and interference producing signals that arrive at angles, relative to the direction that the external antenna is focused, outside the horizontal beamwidth of the external antenna. The desired effect of the directed antenna is to isolate the in-building system from all RF signals other than those used at the primary donor site. They also use one or more low profile antennas located within the interior of the structure, strategically placed to provide coverage in areas where the RF signal levels and/or quality are not adequate to support reliable transmissions. The internal antennas are linked together by an infrastructure comprised of coaxial fiber optic and/or network cables and power splitters. The infrastructure is typically connected with the external antenna through a bi-directional amplifier (BDA), a device that increases the strength of the signal passing through it, either as the signal is received from the transmission tower to be transmitted to the wireless communication device (the signal downlink) or as the signal is received from the wireless communication device to be transmitted to the transmission tower (the signal uplink). In such a system, the RF signals are 1) received from the transmission tower by the external antenna and connected to the BDA; 2) amplified by the BDA; 3) distributed via the system infra-structure to the internal antennas, whose quantity and location inside the facility are appropriate to meet system requirements; and 4) radiated at a sufficient level to support reliable radio communications. The net effect is to allow the signals to pass between the transmission tower and the external antenna and between the wireless communication device and the internal antennas with relatively few intervening barriers. This minimization of intervening barriers, together with the signal amplification provided by the BDA greatly improves in-building performance of wireless communication devices.
[0004] In-building radio frequency communications systems are well known in the prior art, and may be implemented in any number of ways. See, e.g., Point-To-Multipoint Digital Radio Frequency Transport, U.S. Pat. No. 6,704,545 (Wala), issued Mar. 9, 2004; Communication System Comprising An Active-Antenna Repeater, U.S. Pat. No. 5,832,365 (Chen, et al.), issued Nov. 3, 1998; Method Of Locating A Mobile Station In A Mobile Telephone, U.S. Pat. No. 5,634,193 (Ghisler), issued May 27, 1997. However, while these systems are designed to handle the communications within a building, they all depend on reliable signals from the radio frequency transmission tower to support in-building transmissions. Thus, in-building signal enhancement tends to be susceptible to failure if there is an interruption or degradation of service at the external radio frequency transmission tower. This may result from a mechanical failure, a planned maintenance shutdown, environmental factors such as a lightning strike, or other causes, most of which are beyond the control or even awareness of the end use of the wireless communications device. In-building radio frequency communications systems known in the prior art are unable to recover from such interruptions and thus fail to provide the level of quality and reliability desired by end users.
[0005] One class of in-building frequency communications system known in the art does exemplify some failure recovery properties. Where an omni-directional antenna is used as the external antenna for an in-building system, by design the omni-directional antenna sends and receives RF signals equally in the horizontal plane, compared to a directional antenna, which will focus RF energy from approximately 15° to 100° of the horizontal plane. When an omni-directional antenna is used as the external antenna for an in-building system, there may be some degree of radio frequency transmission site diversity due to the inherent ability of the omni-directional antenna to transmit/receive RF signals equally in the horizontal plane. Under this scenario, signals from more than one radio frequency transmission tower may be connected into the in-building system and if signals from one radio frequency transmission tower fail, signals from a different radio frequency tower may be available to provide a level of coverage inside the facility. However, this configuration does not allow for specific redirection for precise control over alternative RF signal sources. The present invention, by placing such control with the system designer, is an improvement over in-building systems that have been designed to provide radio frequency transmission tower diversity through the use of an omni-directional external antenna.
[0006] The present invention is directed to an in-building radio frequency communications system with the capability to automatically transfer RF signals to the in-building system from multiple radio frequency transmission towers. As such, it offers improved RF signal access reliability over known systems.
[0007] It is an object of this invention to provide a fault tolerant in-building radio frequency communications system which minimizes disruptions due to failure of the RF signals from the primary radio frequency transmission tower.
[0008] It is a further object of this invention to provide a donor site diversity system which continuously detects the strength and quality of RF signals from a primary radio frequency transmission tower in order to automatically switch an in-building radio frequency communications system to an ancillary radio frequency transmission tower whenever the strength and quality of RF signals from a primary radio frequency transmission tower fall below an acceptable threshold. Other objects of this invention will be apparent to those skilled in the art from the description and claims which follow.
SUMMARY
[0009] The present invention is directed to an in-building radio frequency communications system with fault tolerant capability when RF signals from the primary radio frequency transmission tower are compromised or fail. Specifically, the invention relates to an improved system which incorporates into an in-building radio frequency communications system a primary external antenna and at least one ancillary external antenna, with the primary external antenna oriented to receive and transmit RF signals from and to a primary transmission tower, and the ancillary external antenna oriented to receive and transmit RF signals from and to one (or more) ancillary transmission towers.
[0010] The present invention further integrates an RF signal detection and switching mechanism into the in-building radio frequency communications system, the said detection and switching mechanism having two functions: 1) the detection mechanism constantly monitors the strength and quality of the RF signals received from the primary transmission tower; and 2) whenever the strength and/or quality of those RF signals deteriorates below a certain threshold, the switching mechanism redirects communications for the in-building radio frequency communications system to the ancillary transmission tower. The redirection of communication signals is achieved by toggling a switch within the switching mechanism, resulting in the circuit between the in-building system and the primary external antenna being interrupted and the circuit between the in-building system and the ancillary external antenna being completed, thereby establishing communications with the ancillary transmission tower. When the switching mechanism detects sufficient signal quality and/or strength in the RF signals received from the primary transmission tower, the switch is toggled to complete the circuit between the in-building system and the primary external antenna and to interrupt the circuit between the in-building system and the ancillary external antenna, thereby re-establishing communications with the primary transmission tower.
[0011] The above-described improvements to in-building radio frequency communications systems increase the reliability of communications in the event of disruptions from the primary transmission tower. By automatically redirecting the RF signal to a different transmission tower having sufficient performance criteria, the invention minimizes communications interruptions to in-building users of the system, achieving high levels of overall fault tolerance in the system.
[0012] The invention also contemplates using any number of ancillary external antennas directed at a like number of ancillary transmission towers. The ancillary transmission towers are prioritized, and the RF signal strength/quality detection component of the invention is employed for each ancillary transmission tower, except for the ancillary transmission tower designated as lowest priority. Upon detecting a sufficient loss of signal strength or quality from the primary transmission tower, the switching mechanism toggles to each successive ancillary transmission tower in turn, by order of priority, based on the detected signal strength/quality, until one receiving a sufficient strength and quality signal is detected. The strength and quality of signals received from the various transmission towers may be continuously monitored, with the switching mechanism toggling to the highest priority transmission tower having sufficient signal strength and quality. This configuration works best in densely populated geographies having multiple transmission towers within range of the system.
[0013] Other features and advantages of the invention are described below.
DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic drawing depicting the basic components of the present invention, including a donor site diversity system.
[0015] FIG. 2 is a schematic drawing depicting the basic components of the present invention, together with detail of the components comprising the donor site diversity system.
[0016] FIG. 2A is a schematic drawing depicting the basic components of the present invention, together with detail of the components comprising the signal splitting means of the donor site diversity system.
[0017] FIG. 3 is a schematic drawing depicting the basic components of the present invention, together with detail of the components comprising the donor site diversity system when multiple ancillary antennas are used.
[0018] FIG. 4 is a flowchart showing the process for determining which RF signal transmission tower should be used when the in-building radio frequency communication system comprises a primary external antenna and a single ancillary external antenna.
[0019] FIG. 5 is a flowchart showing the process for determining which RF signal transmission tower should be used when the in-building radio frequency communication system comprises a primary external antenna and multiple ancillary external antennas.
DESCRIPTION OF THE INVENTION
[0020] The invention is an improvement on known in-building radio frequency communications systems designed to be installed and used within structures, such as office buildings, power generation plants, correctional facilities, etc. The basic in-building system is comprised of the following components: a primary external antenna 32 , an ancillary external antenna 34 , an internal antenna 30 , a donor site diversity system 10 , and a bi-directional amplifier 20 . These components are networked together to form the in-building radio frequency communications system. In one embodiment, the donor site diversity system 10 is connected with the primary external antenna 32 and with the ancillary external antenna 34 by coaxial cables and/or fiber optic cables, and the bidirectional amplifier 20 is connected with the donor site diversity system 10 and with the internal antenna 30 by coaxial cables and/or fiber optic cables. This configuration is shown in FIG. 1 .
[0021] The primary external antenna 32 must be configured to receive and transmit RF signals 5 , which are used for communications with cell phones, two-way radios, and the like. The primary external antenna 32 typically should be located on the exterior of a structure where it can be directed to a primary RF signal transmission tower 42 , such that the primary external antenna 32 is capable of transmitting and receiving RF signals 5 to and from the primary RF signal transmission tower 42 . In the preferred embodiment, the primary external antenna 32 is located on the roof of the structure, or other location with an unobstructed path to the primary RF signal transmission tower 42 . The primary RF signal transmission tower 42 is selected as providing the strongest and/or highest quality RF signal 5 available to connect with the in-building radio frequency communications system.
[0022] The ancillary external antenna 34 must also be configured to receive and transmit RF signals 5 . The ancillary external antenna 34 typically should be located on the exterior of the structure where it can be directed to an ancillary RF signal transmission tower 44 , such that the ancillary external antenna 34 is capable of transmitting and receiving RF signals 5 to and from the ancillary RF signal transmission tower 44 . Because the ancillary external antenna 34 is directed to an ancillary RF signal transmission tower 44 generating RF signals 5 which when received are of a lower strength and/or quality than the RF signals 5 generated by the primary RF signal transmission tower 42 , the ancillary external antenna 34 may be required to be of higher gain and greater directivity; for example, the ancillary external antenna 34 may be a parabolic grid-type antenna, whereas the primary external antenna 32 may be of lower gain and directivity, such as a corner reflector or yagi type antenna. Other types of higher gain and greater directivity antennas may also be used. Use of a higher gain and greater directivity ancillary external antenna 34 increases the likelihood that the RF signals 5 received from the ancillary RF signal transmission tower 44 and passed on to the bi-directional amplifier 20 will be of comparable strength and quality as those received from the primary RF signal transmission tower 42 . In the preferred embodiment, the ancillary external antenna 34 is located on the roof of the structure. The ancillary RF signal transmission tower 44 is selected as providing the next strongest and/or highest quality RF signal 5 available to the in-building radio frequency communications system, after the primary RF signal transmission tower 42 .
[0023] The internal antenna 30 must be configured to receive and transmit RF signals 5 . The internal antenna 30 is typically a low-profile antenna with a power output significantly less than that of the primary 42 and secondary 44 radio transmission towers. The internal antenna(s) 30 typically is located within the interior of the structure where it is capable of transmitting and receiving RF signals 5 to and from wireless communication devices 50 located within the structure. In the preferred embodiment, multiple internal antennas 30 are located within the structure, with each internal antenna 30 configured to receive and transmit RF signals 5 . The multiple internal antennas 30 are distributed throughout the interior of the structure so as to provide the greatest practical coverage within the structure, such that each of the internal antennas 30 is capable of transmitting and receiving RF signals 5 to and from nearby wireless communication devices 50 . Each of the internal antennas 30 is connected with the bi-directional amplifier 20 , either directly or indirectly via a network of cables. In the preferred embodiment, the network connecting the internal antennas 30 is comprised of coaxial cables, although other infrastructure configurations exist, such as fiber optic and network (CAT5/6) cable type systems.
[0024] The bi-directional amplifier 20 may be any type of RF signal amplifier known in the art capable of increasing the strength of RF signals 5 . The bi-directional amplifier 20 must be capable of increasing the strength of RF signals 5 downlinked from RF signal transmission towers to be transmitted to personal communications devices, and capable of increasing the strength of RF signals 5 uplinked from wireless communication devices to be transmitted to RF signal transmission towers. The bi-directional amplifier 20 is connected with the donor site diversity system 10 , from which it receives the downlinked RF signals 5 and to which it sends uplinked RF signals 5 , and is connected with the internal antenna 30 , from which it receives the uplinked RF signals 5 and to which it sends downlinked RF signals 5 . In the preferred embodiment, the bi-directional amplifier 20 is located proximate to the donor site diversity system 10 .
[0025] The donor site diversity system 10 is connected with the primary external antenna 32 and with the ancillary external antenna 34 . The donor site diversity system 10 monitors the strength and quality of the RF signals 5 received by the primary external antenna 32 from the primary RF signal transmission tower 42 . The donor site diversity system 10 is further capable of switching the communication connection between the primary RF signal transmission tower 42 and the ancillary RF signal transmission tower 44 , based on the strength and quality of the RF signals 5 received from the primary RF signal transmission tower 42 .
[0026] In one embodiment, the donor site diversity system 10 comprises a primary circuit 12 , an ancillary circuit 14 , a RF signal switch 16 , and a RF signal detector/sensor 18 . This configuration is shown in FIG. 2 .
[0027] The primary circuit 12 is configured to establish a communications connection between the primary external antenna 32 and the bi-directional amplifier 20 such that RF signals 5 may travel between the primary external antenna 32 and the bi-directional amplifier 20 . The ancillary circuit 14 is configured to establish a communications connection between the ancillary external antenna 34 and the bi-directional amplifier 20 such that RF signals 5 may travel between the ancillary external antenna 34 and the bi-directional amplifier 20 . The primary circuit 12 and the ancillary circuit 14 are mutually exclusive; that is, when the primary circuit 12 is active, the ancillary circuit 14 is inactive, and RF signals 5 are received by and sent from the in-building radio frequency communications system solely through the primary circuit 12 ; and when the ancillary circuit 14 is active, the primary circuit 12 is inactive, and RF signals 5 are received by and sent from the in-building radio frequency communications system solely through the ancillary circuit 14 .
[0028] The RF signal switch 16 is configured to activate and deactivate the primary circuit 12 and to activate and deactivate the ancillary circuit 14 . In the preferred embodiment, the RF signal switch 16 toggles an interlink 17 between the primary circuit 12 and the ancillary circuit 14 , such that the ancillary circuit 14 is interrupted when the interlink 17 is toggled to and completes the primary circuit 12 , and the primary circuit 12 is interrupted when the interlink 17 is toggled to and completes the ancillary circuit 14 .
[0029] The RF signal detector/sensor 18 is configured to monitor the strength and quality of the RF signals 5 received from the primary RF signal transmission tower 42 . In one embodiment, the RF signal detector/sensor 18 comprises a monitoring means and a logic processor appropriate to the target RF signals 5 enhancing the in-building environment. The monitoring means is configured to monitor the strength and quality of the RF signals 5 received from the primary RF signal transmission tower 42 . In the preferred embodiment, the monitoring means is configured to continuously monitor the strength and quality of the RF signals 5 received from the primary RF signal transmission tower 42 . The logic processor of the RF signal detector/sensor 18 is connected with the RF signal switch 16 , and is configured to determine the sufficiency of the strength and quality of the RF signals 5 received from the primary RF signal transmission tower 42 . The threshold criteria for determining the sufficiency of the strength and quality of the RF signals 5 may be preset, or altered by the user, or dynamically altered automatically depending on environmental criteria. The logic processor compares the sufficiency of the strength and quality of the RF signals 5 against the threshold criteria, and communicates a positive signal to the RF signal switch 16 if the sufficiency of the strength and quality of the RF signals 5 meets or exceeds the threshold criteria, and communicates a negative or ground signal to the RF signal switch 16 if the sufficiency of the strength and quality of the RF signals 5 fails to meet or exceed the threshold criteria. The RF signal switch 16 in turn toggles the interlink 17 to complete the primary circuit 12 when a positive signal is received, thereby interrupting the ancillary circuit 14 , and toggles the interlink 17 to complete the ancillary circuit 14 when a negative signal is received, thereby interrupting the primary circuit 12 . This process is shown in FIG. 4 .
[0030] In one embodiment, the donor site diversity system 10 further comprises a signal splitting means for directing RF signals 5 to both the RF signal detector/sensor 18 and the RF signal switch 16 . In the preferred embodiment the signal splitting means comprises an unequal power signal splitter 60 , a two-way power divider 64 , and a variable attenuator 68 . The unequal power signal splitter 60 further has an input port 61 , a high power output port 62 , and a low power output port 63 . The two-way power divider 64 further has an input port 65 , a first equal power distribution output port 66 , and a second equal power distribution output port 67 . The unequal power signal splitter 60 is located in-line with the primary circuit 12 , whereby the unequal power signal splitter 60 is in connection with the primary external antenna 32 through the input port 61 of the unequal power signal splitter 60 , the unequal power signal splitter 60 is in connection with the RF signal switch 16 through the high power output port 62 of the unequal power signal splitter 60 , and the unequal power signal splitter 60 is in connection with the two-way power divider 64 through the low power output port 63 of the unequal power signal splitter 60 and into the input port 65 of the two-way power divider 64 . RF signals 5 from the primary external antenna 32 enter the unequal power signal splitter 60 through its input port 61 and are directed simultaneously to the RF signal switch 16 and the two-way power divider 64 . The two-way power divider 64 in turn is in connection with a test port through the first equal power distribution output port 66 of the two-way power divider 64 and with the variable attenuator 68 through the second equal power distribution output port 67 of the two-way power divider 64 . The variable attenuator 68 is in connection with the RF signal detector/sensor 18 . The variable attenuator 68 is used to adjust the threshold level of the RF signal detector/sensor 18 . RF signals received by the primary external antenna 32 are transmitted along the primary circuit 12 to the unequal power signal splitter 60 , whereby the RF signals 5 are then split between the RF signal switch 16 and the RF signal detector/sensor 18 (the latter by way of the two-way power divider 64 and variable actuator 68 ). In using the combination of the unequal power signal splitter 60 and the two-way power divider 64 to send RF signals 5 to the RF signal switch 16 and the RF signal detector/sensor 18 , the monitoring means of the donor site diversity system 10 can monitor the strength and/or quality of the RF signals 5 received from the primary RF signal transmission tower 42 on a continuous basis. The RF signal detector/sensor 18 then directs the RF signal switch 16 to toggle between the primary circuit 12 and the ancillary circuit 14 as appropriate.
[0031] In an alternate embodiment of the invention, the in-building radio frequency communications system comprises multiple ancillary external antennas 34 . This configuration is shown in FIG. 3 . Each of the ancillary external antennas 34 is configured to receive and transmit RF signals 5 , and each of the ancillary external antennas 34 is located on the exterior of the structure, preferably on the roof, where it can be directed to a corresponding ancillary RF signal transmission tower 44 , one ancillary RF signal transmission tower 44 per ancillary external antenna 34 . Each ancillary external antenna 34 is capable of transmitting and receiving RF signals 5 to and from its corresponding ancillary RF signal transmission tower 44 . As in the preferred embodiment, the ancillary external antennas 34 may be required to be of higher gain and greater directivity than the primary external antenna 32 . For each of the ancillary external antennas 34 , there is a corresponding ancillary circuit 14 . Each such ancillary circuit 14 is configured to establish a connection between the corresponding ancillary external antenna 34 and the bi-directional amplifier 20 , with one ancillary circuit 14 per ancillary external antenna 34 , such that RF signals 5 may travel between each ancillary external antenna 34 and the bi-directional amplifier 20 . Each of the ancillary RF signal transmission towers 44 is prioritized based on the strength and/or quality of the RF signals 5 received by the in-building radio frequency communications system under optimal conditions, with all ancillary RF signal transmission towers 44 having a lower priority than the primary RF signal transmission tower 42 .
[0032] In this embodiment, the donor site diversity system 10 is connected with each of the multiple ancillary external antennas 34 , in addition to the primary external antenna 32 . As in the preferred embodiment, the RF signal detector/sensor 18 of the donor site diversity system 10 monitors the strength and quality of the RF signals 5 received by the primary external antenna 32 from the primary RF signal transmission tower 42 . However, the RF signal detector/sensor 18 also monitors the strength and quality of the RF signals 5 received by each of the ancillary external antennas 34 from their corresponding ancillary RF signal transmission tower 44 , except for the ancillary RF signal transmission tower 44 having the lowest priority, which is not monitored. The monitoring means may be configured to continuously monitor the strength and quality of the RF signals 5 received by each of the external antennas 32 , 34 .
[0033] The logic processor of the RF signal detector/sensor 18 is configured to determine the sufficiency of the strength and quality of the RF signals received from each of the monitored radio frequency signal transmission towers 42 , 44 , in conjunction with the priority established for each of the RF signal transmission towers 42 , 44 . The logic processor compares the sufficiency of the strength and quality of the RF signals 5 received from each monitored radio frequency transmission tower 42 , 44 against the threshold criteria, in order of priority, and for each such tower 42 , 44 communicates a positive signal to the RF signal switch 16 if the sufficiency of the strength and quality of the RF signals 5 meets or exceeds the threshold criteria, and communicates a negative or ground signal to the RF signal switch 16 if the sufficiency of the strength and quality of the RF signals 5 fails to meet or exceed the threshold criteria. The RF signal switch 16 in turn toggles the interlink 17 to complete the circuit 12 , 14 corresponding to the positive signal, thereby interrupting all other circuits. Once a positive signal is communicated by the logic processor to the RF signal switch 16 , the process is reset and the logic processor repeats the process beginning with the primary RF signal transmission tower 42 .
[0034] The determination of which RF signal transmission tower 42 , 44 is to be used for the communication connection by the donor site diversity system 10 in this embodiment is illustrated in FIG. 5 . The logic processor of the RF signal detector/sensor 18 begins the process with an analysis of the RF signals 5 received from the primary RF signal transmission tower 42 . When the strength and quality of the RF signals 5 received from the primary RF signal transmission tower 42 is sufficient, the donor site diversity system 10 switches the communications connection to the primary RF signal transmission tower 42 , along the primary circuit 12 , and all ancillary circuits 14 are disabled. The process then repeats. If, however, the strength and quality of the RF signals 5 received from the primary RF signal transmission tower 42 is insufficient, the donor site diversity system 10 determines whether the strength and quality of the RF signals 5 received from the ancillary RF signal transmission tower 44 having the highest priority is sufficient; if so, the donor site diversity system 10 switches the communications connection to that ancillary RF signal transmission tower 44 , along its corresponding ancillary circuit 14 , disabling the primary circuit 12 and all other ancillary circuits 14 , and the process then repeats. If the strength and quality of the RF signals 5 received from the ancillary RF signal transmission tower 44 having the highest priority is insufficient, the strength and quality of the RF signals 5 received from the ancillary RF signal transmission tower 44 having the next highest priority is analyzed by the donor site diversity system 10 , etc. If no monitored ancillary FR signal transmission tower 44 is transmitting RF signals 5 of sufficient strength and quality, the donor site diversity system 10 switches the communications connection to the ancillary RF signal transmission tower 44 having the lowest priority, along its corresponding ancillary circuit 14 , disabling the primary circuit 12 and all other ancillary circuits 14 .
[0035] This embodiment may also comprise multiple signal splitter means 60 A, 60 B. Each signal splitter means is configured as explained above. One signal splitter means 60 A is located in-line with the primary circuit 12 between the primary external antenna 32 and the RF signal switch 16 , and is in connection with the RF signal detector/sensor 18 . Each of the monitored ancillary circuits 14 also is assigned a signal splitter means 60 B, with one signal splitter means for each such ancillary circuit 14 . Each such signal splitter means is located in-line with its ancillary circuit 14 between the corresponding ancillary external antenna 34 and the RF signal switch 16 , and is in connection with the RF signal detector/sensor 18 . RF signals 5 received by the primary external antenna 12 and by each monitored ancillary external antenna 14 are transmitted through the corresponding signal splitter means to both the RF signal switch 16 and the RF signal detector/sensor 18 . In using the signal splitter means, the monitoring means of the donor site diversity system 10 can monitor the strength and/or quality of the RF signals 5 received from the RF signal transmission towers 42 , 44 on a continuous basis.
[0036] Modifications and variations can be made to the disclosed embodiments of the invention without departing from the subject or spirit of the invention as defined in the following claims. | An improved in-building radio frequency communications system with automatic failover recovery comprising a primary external antenna and at least one ancillary external antenna, each antenna directed to a primary transmission tower and to at least one ancillary transmission tower, respectively, and a diversity site donor system capable of monitoring the strength and/or quality of the radio frequency signals received from the primary transmission tower and switching communications between the primary transmission tower and the ancillary transmission tower(s) based on the strength and/or quality of the radio frequency signals received from the primary transmission tower. | 7 |
FIELD
[0001] The present invention, a passive event detection system, is directed generally to systems and methods for monitoring individuals need for assistance, and more particularly, to methods and systems for detecting individuals who are incapacitated and in need of assistance.
BACKGROUND
[0002] Elderly individuals face an increasing likelihood of a traumatic event which could render the individual incapable of calling for help, for example a fall which renders them unconscious or immobile. Clearly, those individuals living alone are at an even higher risk of being unable to communicate with someone in the event of such an event.
[0003] Physically impaired and/or mentally impaired individuals may be at an increased risk of injury, and may be at an increased risk of being unable to communicate or operate an active alert upon such an injury. This group includes individuals who may be permanently impaired, or temporarily impaired, for example those recovering from an injury or surgery.
[0004] Individuals who enjoy adventurous or “risky” activities on their own, such as biking, running or rock climbing, face a larger risk of being injured.
[0005] For many injuries, it is imperative to get appropriate care and medical attention as soon as possible. Early intervention often is the difference between life and death. With the baby boomer generation entering into the older years, the need for a passive alert system for non-geriatric populations is extremely high.
[0006] What is needed is a new way to identify the occurrence of an event that may have caused traumatic injury to the user, while minimizing false-positive event detections. What is needed is technology that fosters peace of mind among at-risk individuals and their loved ones. What is needed is a passive event detection system that would output an event notification when a user suffers a traumatic injury.
SUMMARY
[0007] Embodiments described herein overcome the disadvantages described above. These, and other advantages, are provided by, for example, a method performed by one or more processors associated with one or more computing devices. The method accesses, by one or more of the processors, one or more data streams from a plurality of sensors, the sensors comprising an accelerometer and heart-rate monitor worn by an individual, in which the data streams include accelerometer data of the individual from the accelerometer and heart-rate data of the individual from the heart rate monitor, and self-reported demographic data of the individual collected by manual input by the individual, a first data set from the sensor data streams collected upon initial usage by the individual, the person being engaged in activity monitoring for the first time, and data received from continuous monitoring of the sensor data streams collected subsequent to baseline. The method detects if certain thresholds are met indicating the person is likely to have suffered a traumatic event where they need assistance, detects and monitors, by one or more of the processors, a set of trigger conditions comprising baseline accelerometer data and baseline heart-rate data, compared with current real time accelerometer data and heart-rate data, in which the baseline data measures normal activity, and in which the real time data is monitored for thresholds noting traumatic event likelihood. The method determines, by one or more of the processors, a current “Event Detection” profile of the person based on the analysis of the first data set (initial baseline data) and second data set (indicating a traumatic event) with respect to each other.
[0008] These and other advantages are also provided by, for example, a passive event detection system for a traumatic event. The system includes an input configured to receive data collected by a plurality of sensors, a computer-readable storage medium configured to store computer-executable instructions, and a computer processor configured to execute the computer-executable instructions. The computer-executable instructions may include instructions for accessing, by one or more of the processors, one or more data streams from a plurality of sensors, the sensors comprising an accelerometer and heart-rate monitor worn by an individual, in which the data streams comprise accelerometer data of the individual from the accelerometer and heart-rate data of the individual from the heart rate monitor, and self-reported demographic data of the individual collected by manual input by the individual a first data set from the sensor data streams collected upon initial usage by the individual, the person being engaged in activity monitoring for the first time, and data received from continuous monitoring of the sensor data streams collected subsequent to baseline, detecting if certain thresholds are met indicating the person is likely to have suffered a traumatic event where they need assistance, detecting and monitoring, by one or more of the processors, a set of trigger conditions comprising baseline accelerometer data and baseline heart-rate data, compared with current real time accelerometer data and heart-rate data, wherein the baseline data measures normal activity, and in which the real time data is monitored for thresholds noting traumatic event likelihood, and determining, by one or more of the processors, a current “Event Detection” profile of the person based on the analysis of the first data set (initial baseline data) and second data set (indicating a traumatic event) with respect to each other.
BRIEF DESCRIPTION OF THE FIGURES
[0009] FIG. 1 shows a block diagram of the passive event detection system for individuals to detect traumatic events using physiological and environmental factors, according to one aspect of this disclosure.
[0010] FIG. 2 shows a plurality of sensors that may provide data to the system, according to one aspect of this disclosure.
[0011] FIG. 3 is a flowchart showing a method for detecting a potentially incapacitating traumatic event, according to one aspect of this disclosure.
DETAILED DESCRIPTION
[0012] The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention as defined in the following claims, and their equivalents, in which all terms are to be understood in their broadest possible sense unless otherwise indicated.
[0013] Described herein are embodiments of a system and method of passive and active alert system for individuals to detect traumatic events using physiological and environmental factors. Embodiments overcome the problems described above, namely that the system can function passively and create an event notification in the event that the individual is incapacitated and cannot independently alert necessary personnel. For example, embodiments monitor an individual's heart rate (through heart rate monitor data) and movement (through accelerometer data) to estimate when an individual may have suffered a traumatic event and is in need of assistance.
[0014] Embodiments described herein use physiologic and environmental sensors to detect and passively (without the input of the injured individual) create an event notification. Embodiments may utilize various processes and systems to act upon this event notification, including then notifying Emergency Medical Services (“EMS”) and/or a set of contacts defined by the user. While there are numerous applications for embodiments described herein, the following provides three illustrative examples: elderly individuals, physically and/or mentally impaired individuals, and individuals engaging in adventurous or “risky” activities. In each example, prompt medical care often makes the difference in avoiding a more serious injury, or even death.
[0015] Embodiments provide a new way to identify the occurrence of an event that may have caused traumatic injury to the user. A heart rate monitor and accelerometer worn by the user (and potentially other sensors) provide information which is processed by embodiments described herein to determine when a potentially traumatic event has occurred.
[0016] A purpose of embodiments of a passive and active alert system for individuals to detect traumatic events using physiological and environmental factors is to foster peace of mind among at-risk individuals and their loved ones. Embodiments passively monitor certain sensors, e.g., heart rate and accelerometer, worn by the user; based on signals from these sensors, embodiments can make educated assumptions about when a traumatic event occurs (“event”).
[0017] Upon identification of an event, embodiments of a passive event detection system for individuals to detect traumatic events using physiological and environmental factors would output an event notification. This event notification could then be acted upon, including then notifying EMS and/or a set of contacts defined by the user of the embodiments. The event notification could include specific information that would facilitate a swift and proper response, thereby reducing the chance that an event will go undetected. The user can also actively identify an event, but the passive feature of embodiments described herein sets the passive and active alert system for individuals to detect traumatic events using physiological and environmental factors apart from product offerings currently available. Further, the use of the heart rate sensor data allows the system to minimize false positive alerts (alerts in which an event is detected but an event did not actually occur). This false positive might occur if the system only relied on accelerometer data. For example, if the system was dropped but not worn by the individual, the accelerometer would register an event. However, the passive event detection system would examine the heart rate data to determine if the system was actually worn by the individual. For example, if no heart rate was detected, then the system may determine that the individual was not wearing the system. Therefore, the system may not output an event notification.
[0018] With reference now to FIG. 1 , shown is a block diagram of a system illustrating exemplary hardware components for implementing embodiments of system and method for system and method of passive event detection for individuals to detect traumatic events using physiological and environmental factors. Computer system 500 , or other computer system similarly configured may run method 100 (as described below) directly or indirectly through a subsystem component.
[0019] Computer system 500 typically includes a processor or processors 505 and memory 510 , and may include an output device 515 . Computer system 500 may contain an input device 520 . Input device 520 would be used to receive sensor data, including but not limited to accelerometer sensor data 701 and 702 and heart rate sensor data 711 and 712 , as described below. Computer system 500 may store input data on one or more database structures in secondary storage 525 . Computer system 500 may also include a network connection 535 , which may be connected to network 540 . The network connection 535 which may be used, in addition to or in lieu of the input device 520 , to receive sensor data such as accelerometer sensor data 701 and 702 and heart rate sensor data 711 and 712 . The network connection 535 may also be used to transmit an event notification. One of ordinary skill in the art would readily recognize that any network 540 , such as the Internet or Local Area Network (LAN), may be used. Computer system 500 may also be connected to a plurality of sensors 200 (shown in FIG. 2 ). The computer system 500 may be connected to the plurality of sensors 200 through a wired or a wireless connection. For example, if a wired connection is used, data generated by the plurality of sensors 200 may be received by the input device 520 . If a wireless connection is used, data generated by the plurality of sensors 200 may be received by the network connection 535 via the network 540 . In other aspects of this disclosure, at least one sensor of the plurality of sensors 200 may use a wired connection while at least another one of the sensors of the plurality of sensors 200 may use a wireless connection.
[0020] With reference now to FIG. 2 , shown is exemplary embodiment of a plurality of sensors 200 that may provide data to computer system 500 . Sensor 700 is an accelerometer and collects data including but not limited to a date and time stamp 701 and a sensor value 702 . The sensor has an output device 703 . An additional sensor 710 is a heart rate monitor and similarly collects data including but not limited to a date and time stamp 711 and a sensor value 712 . The sensor has an output device 713 . The sensor output devices 703 , 713 may be used to output collected data to the computer system 500 . For example, the output devices 703 , 713 may transmit, using wired or wireless means, data collected to the input device 520 or to the network connection 535 via network 540 . One of ordinary skill in the art would readily recognize that any number and any type of sensor may be utilized.
[0021] With reference now to FIG. 3 , shown is exemplary embodiment of a method 100 for detecting a potentially incapacitating traumatic event. An embodiment uses a wearable accelerometer sensor 700 and heart rate sensor 710 (for example, a wrist-based smart watch or health-band). Embodiments include an algorithm, which based on certain data patterns observed in heart rate data and based on certain data patterns observed in accelerometer data, determines that an “event” has occurred. Examples of “events” are: falls, activity related incidents (e.g., bike crash, treadmill fall) or other traumatic events (e.g., car crash).
[0022] Upon starting method 100 , an evaluation is made as to whether or not user configuration information 230 is complete. If it is not complete, block 245 is reached and the user is prompted with a series of questions, the answers to which comprise user information. Questions may include age, height, weight, and any known health conditions. When user information is complete, decision block 110 is reached, at which point the user selects normal mode 120 or active mode 115 . Active mode 115 would be selected during exercise or otherwise strenuous periods of activity by the user, and normal mode 120 would be used at all other times.
[0023] Normal mode 120 is a primary mode for method 100 . A primary mode selection would notify the algorithm that both the accelerometer sensor 700 data and the heart rate sensor 710 data should be evaluated by method 100 , periodically or continuously, to determine if consecutive sensor data 701 and 702 reveal a change in acceleration that exceeds a threshold value. The threshold value may be set to any deviation from the baseline value. For example, the threshold may be a 50% change from the baseline accelerometer data or heart rate data. However, one of ordinary skill in the art would readily recognize that any deviation, such as 10% or 25%, from the baseline may be set as the threshold.
[0024] Upon changes in heart rate sensor data 712 that exceed the threshold shown in block 130 , accelerometer sensor data 702 is evaluated for changes after threshold 130 was exceeded in block 145 . If there are continued changes in sensor data 702 then these changes are compared to the threshold in block 175 ; changes in sensor data 702 which do not exceed the threshold in block 175 return method 100 back to normal mode 120 . Changes in sensor data 702 which do exceed the threshold in block 175 are then subsequently analyzed in block 215 for normal motion. If normal motion is detected in block 215 , then the method 100 may return to normal mode 120 . If there are no continued changes in sensor data 702 then an event is detected in block 225 .
[0025] Upon changes in accelerometer sensor data 702 that exceed the threshold in block 135 , heart rate sensor 710 data is evaluated for consecutive sensor data 711 and 712 over a time period ranging from prior to exceeding the threshold in block 135 and until an event is either detected in decision block 185 or decision block 205 , or the user returns to normal mode in decision block 120 . Heart rate sensor 710 data that exceed the threshold in block 150 triggers event 185 . Heart rate sensor 710 data that do not exceed the threshold in block 150 then evaluates for a heart rate signal block 190 . Detection of a signal in block 190 triggers event detection in block 205 . If heart rate signal in block 190 is not detected, then the user is returned to normal mode in block 120 .
[0026] The method 100 may provide for an alternate mode if the wearer selects an active mode in block 115 . A selection of the active mode 115 would notify the method 100 that heart rate sensor 710 data is expected to be higher than when in normal mode 120 . Method 100 may, when in active mode 115 , rely primarily on data from accelerometer sensor 700 . A higher than normal heart rate is expected, and therefore the triggers for an event may be based on altered heart rate thresholds and/or may be based primarily on data from the accelerometer. In active mode 115 at decision blocks 116 and 126 , the method 100 may evaluate heart rate sensor 710 data to ensure that a heart rate signal is detected. If no heart rate sensor 710 data is detected, the method 100 may return to active mode 115 .
Alternatives
[0027] Embodiments of the passive and active alert system for individuals to detect traumatic events using physiological and environmental factors may include a number of different sensors, operational modes, options and other features that may affect how the passive and active alert system operates. For example:
Sensors—utilize different, and/or additional sensors, including wearable, non-wearable, data-based, etc. A sensor typically measures a physical quantity and converts it into a signal that an observer or an instrument can read. For example, a mercury-in-glass thermometer converts a measured temperature into expansion and contraction of a liquid that can be read on a calibrated glass tube. A thermocouple converts temperature to an output voltage that a voltmeter can read. For accuracy, sensors are generally calibrated against known standards. Algorithms included in the passive and active alert system may utilize additional sensor data points and logic to identify an event or events. Embodiments may require the storage of sensor data before and after the event for later analysis. Embodiments may require accessing our outputting sensor data for additional analysis or evaluation. Algorithms included in the passive and active alert system may require monitoring longer periods of data. The exact flow of decisions may be updated to improve accuracy and/or speed of event detection. Embodiments may allow for variable and/or configurable settings, relating to threshold levels or other items Processor and accompanying software may be external to, or bundled with, the sensors.
[0036] The terms and descriptions used herein are set forth by way of illustration only and are not meant as limitations. Those skilled in the art will recognize that many variations are possible within the spirit and scope of the invention as defined in the following claims, and their equivalents, in which all terms are to be understood in their broadest possible sense unless otherwise indicated. | Systems and methods of passive and active alert system for individuals to detect traumatic events using physiological and environmental factors. Exemplary methods include receiving sensor data associated with the individual from a plurality of sensors of a monitoring device and determining whether the sensor data satisfies one or more trigger conditions. For each of the trigger conditions satisfied, one or more messages are sent to at least one of the patient monitoring device and/or an external computing device for analysis. Satisfaction of one or more of the trigger conditions may indicate the individual has been incapacitated and is in need of assistance. The sensor data may have been collected from a heart rate sensor and/or an accelerometer. In some embodiments, the trigger conditions are defined by the individual. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of controlling the amount of water which is added into a pulp washing system by monitoring the amount of water in a washed pulp mat leaving the pulp washing system.
2. Description of the Prior Art
Pollution control depends upon the washing operation control whereby if there is insufficient wash water added to the system the washing step is inefficient and increases the pollution.
Poor control can also be in the other direction whereby an excessive amount of wash water is applied and this excess water must be evaporated in the evaporator operation which then causes an excessive energy consumption.
Washing control systems presently in use do not use the water efficiently in that for short periods of time there is an excess of water used followed by a period whereby an insufficient amount is used. This leads to insufficiencies of both kinds described above within the one continuous washing system.
Pulp washing systems are designed to minimize the amount of fresh water needed to wash the black liquor from the pulp produced from a pulp digester. Countercurrent pulp washing techniques are almost exclusively used in order to increase efficiency in the pulp washing system. In conventional countercurrent washing operations, fresh water which is added to the system is generally referred to as shower water because it is sprayed as a shower upon a pulp mat which has been formed in the last of a number of washing operations.
Two important factors which must be understood with relation to the present washing control system are the dilution factor and the displacement factor. These factors influence the determination of the flow rate of shower water as calculated by the present control system and must necessarily be appreciated to enable the control system to permit a satisfactory pulp washing operation.
The dilution factor represents a ratio of the amount of fresh water sprayed onto a pulp mat undergoing a washing operation to the final volume of water contained in the pulp mat as it leaves the washing operation. The amount of fresh water entering the washing system may be expressed in appropriate flow rate units such as liters per minute. The volume of water leaving the washing system in the final washed pulp mat product is expressed in the same units. In countercurrent washing operations recycled water is sprayed on the pulp mat in all but the final washing operation. The dilution factor for each washing operation step prior to the final fresh water treatment is expressed as the ratio of the recycled water sprayed onto the pulp mat to the volume of water contained in the pulp mat which has been treated in the individual washing step.
The displacement ratio is equal to the fractional of the liquor entering the filter drum in the pulp mat which is displaced by water from the spray washer. The ideal displacement ratio would be 1.0 where ideal plug flow existed; however, the ideal situation is not obtained. The displacement factor is primarily a function of the dilution factor but is influenced by such factors as air entrainment in the pulp web, pulp web sheet uniformity, and the temperature of the system. The displacement factor can be determined by an analysis of the amount of dissolved solids which remain in the pulp after washing compared to the dissolved solids which would be in the pulp at the same consistency without any shower flow. In effect, this displacement ratio may be displayed by a comparison between the dissolved solids concentration in the water in the pulp mat exiting the washing system after the washing treatment, and the dissolved solids concentration of the pulp before the final shower water treatment.
While the use of countercurrent washing systems reduces the amount of fresh water which is needed in a pulp washing system, previous attempts to minimize the total amount of fresh shower water introduced into the wash system have proved to be inefficient. Previous systems have not provided for a continuous monitorization and immediate shower flow response to produce a pulp washing system which is continuously efficient in minimizing the shower flow necessary to produce a satisfactorily washed pulp product. The present invention overcomes the deficiencies of the control methods used in the past.
Primarily, two control methods have been used to control pulp washing systems in the past. In the first method a pulp flow rate on the entire set of washers is estimated to be constant and the pulp flow rate is calculated for one washer by correlating a flow measurement and a consistency. The consistency of the pulp leaving the washer drums is not taken into account except in the design of the system. The shower water flow on the last washer is then set by the operator based on hourly tests of the solids content of the liquor in the early stages of the washing operation. The system can be out of balance in both of the ways previously described several times during the hour without detection by the operator. The average liquor solids content can be on target yet the system can be inefficient in producing both high losses to the sewer and excessive water to be evaporated. This can be explained by showing that an overwash for part of the time cannot make up for an insufficient wash the other part of the time.
In the second prior art control method as described in U.S. Pat. No. 4,046,621 to Sexton, the conductivity of the liquid displaced from the pulp mat in the last washing step is measured and this measurement is used to adjust the amount of fresh washing liquid in the last washing stage.
This system is an improvement over the operator control alone but has several disadvantages. The first disadvantage is that conductivity is not precisely related to the liquor solids content as it is greatly influenced by the composition of the solids. Secondly, the large volumes of liquor circulated in the wash system have a large buffering action on the rate of change of liquor conductivity with a change in washing efficiency. In a typical pulp washing system operation at 500 metric tons of pulp per day the liquor volume maintained in each stage filtrate tank will be in the order of 200,000 liters which is recirculated in the wash system at a rate of about 30,000 liters per minute. The shower flow for 1.15 dilution factor would be 2928 liters per minute at 12 percent discharge consistency. Of this 2928 liters per minute approximately 382 liters per minute would penetrate the mat with a perfect displacement system. In a normal balanced system this 382 liters per minute would be mixing continuously with the 200,000 liters in the filtrate tank.
If the shower flow was accidently cut completely off the conductivity system of control would detect a rate of change of only (100×382/200,000)=0.19 percent per minute. This small change in conductivity would not initiate a change in the shower set point until significant inefficiencies in the system had occurred.
SUMMARY OF THE INVENTION
This invention overcomes the problem of the prior art by providing a continuous monitorization system which is used to immediately control the shower flow of fresh water or liquid additives which is introduced into a pulp washing system. Through the use of a monitorization system featuring immediate response in the shower flow control greater efficiency is produced in regulating the shower flow necessary to produce an acceptable washed pulp product. This improvement over the prior wash control processes alleviates the problems produced by wash systems using too much shower water flow, thereby causing excess water to be sent to the evaporators, and by wash systems using too little shower water flow, thereby producing pulp which has not been sufficiently washed creating high pollution loads and economic loss of chemicals from the process.
The foregoing advantages are obtained by the present invention by a process which determines the amount of water content present in a pulp web using a capacitance measurement technique after the web passes over a vacuum break on a rotary drum vacuum filter which is the final step before removal of the pulp in the form of a mat or a web from the washing system. Once the water content of the pulp mat is determined, it may be correlated to control the fresh water shower flow rate, thus minimizing the amount of fresh water needed to satisfactorily clean paper pulp in a countercurrent pulp washing operation. This correlation consists of combining the water content per unit area of the pulp mat, as determined by a capacitance measurement, with the drum filter area, rotational speed of the drum and a dilution factor.
Alternative or secondary measurement apparatus may be employed in the washing system either alone or in conjunction with the capacitance measurement apparatus in order to determine other parameters of the washing operation such as consistency of the pulp mat and the production rate of the pulp mat from the washing system. These measurement devices include apparatus to produce and monitor backscattered nuclear radiation and perturbation of microwave cavities. The nuclear radiation measurement apparatus measures the total mass of pulp and water per unit area of the pulp mat.
Microwave cavity perturbation apparatus can be used to determine the liquid content of the pulp mat in place of the capacitance measurement apparatus when the conductivity of the liquid in the pulp mat is a significant factor such as when the conductivity is affected by changes in chemical concentrations in the liquid in the slurry mat. Through the use of microwave cavity perturbation measurement apparatus, changes in the dielectric losses of the liquid in the pulp mat may be separately detected from the remainder of the dielectric properties such as the dielectric constant. The dielectric losses are responsive to the conductivity of the liquid in the pulp mat and are therefore responsive to the efficiency of the shower flow as a wash. The dilution factor and thus the shower flow will be directly responsive to the measured dielectric losses.
The preferred embodiment for accuracy would combine capacitance measurement for the water and nuclear radiation used for the total mass but in some applications the microwave perturbation techniques may be suitable or even superior.
By using the secondary measurement apparatus to determine the total mass per unit area of the pulp mat leaving the washing system, and by using the capacitance measurement apparatus to determine the water mass per unit area, the pulp mass per unit area leaving the washing system may be determined by substracting the water mass per unit area from the total mass per unit area. This determination permits the calculation of the consistency of the pulp mat exiting the washing system as the consistency is the percentage of solids of the total liquid-solid content of the pulp mat. A measure of the consistency of the pulp mat allows the user to evaluate different conditions of drum speed, mat dilution, press roll pressure, anti-foam agents or drainage aids such that the maximum consistency is obtained. The maximum consistency at any given tonnage rate is known to produce the best wash with the least water as shown by the dilution factor and displacement factor. Obviously the highest consistency at a given tonnage rate contains the least amount of water in the sheet and at any given dilution factor the highest consistency also uses the least amount of water to be evaporated. The highest consistency at these conditions will also allow the best wash possible. It is important therefore to be able to quickly and easily determine the consistency of the pulp mat on the filter. Testing for this consistency by present hand sampling methods is very tedious and inaccurate since such a small sample must be taken. The consistency of the pulp mat is continuously monitored by continuously evaluating the pulp mat characteristics as the pulp mat rotates on the filter drum. Capacitance measurements of the pulp mat on the filter drum are preferrably recorded across the entire surface of the filter drum.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing objects, features, and advantages of the invention will be more fully understood upon a consideration of the following detailed description of preferred forms of the invention, together with the accompanying drawings, in which:
FIG. 1 is a flow schematic of a countercurrent pulp washing operation;
FIG. 2 is an end view of a rotary drum vacuum filter used in conjunction with the pulp washing operation of FIG. 1;
FIG. 3 is a side view of a rotary drum vacuum filter used in conjunction with the pulp washing operation of FIG. 1; and
FIG. 4 is a side view of a rotary drum vacuum filter used in conjunction with the pulp washing operation of FIG. 1;
FIG. 5 is the end view of a rotary drum vacuum filter used in conjunction with the pulp washing operation of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is applicable to pulp washing operations in general, however, the main embodiment is applicable to the standard countercurrent pulp washing system as demonstrated in FIG. 1. Referring to FIG. 1, the overall countercurrent pulp wash system as displayed in FIG. 1 consists of three rotary drum vacuum filters, 4, 4' and 4", three filtrate tanks 8, 8', and 8", two repulpers 10 and 10' and flow lines connecting these individual components in conventional manner.
The pulp and liquor entering this system via a transfer line 20 comes from the digester operation in a wood pulping operation. The amount of water added to the system up to this point is kept to an absolute minimum consistent with good operating procedure in order to maintain the least amount of water that must be evaporated in the subsequent evaporation and chemical recovery system.
The fresh wash water enters the washing system in one location only, through a wash sprayer 1. This fresh water spray through the wash sprayer 1 is hereafter referred to as shower water. The shower water is projected by the wash sprayer 1 onto a pulp mat 2 formed on a tertiary rotary drum vacuum filter 4 which rotates in the direction of the shown arrow. As will be seen, fresh shower water need only be introduced in one location because a countercurrent washing system maximizes the use of water in the system for pulp washing purposes by recycling the filtrate to the previous stages.
Before the pulp mat is subjected to the action of the wash sprayer 1, the pulp mat consists mainly of water supplied from preceeding wash operations, pulp and black liquor. The majority of the water which is contained within the pulp mat formed on the tertiary rotary drum vacuum filter 4 and some of the shower water which is added to the pulp mat by the wash sprayer 1 is drawn from the pulp mat into the tertiary vacuum filter 4 where the water is transferred via a discharge line 5 to a filtrate tank 8. The water which is not removed from the pulp mat 2 by the operation of the vacuum drum filter 4 exits the wash system as a washed pulp mat discharge 16.
The majority of the wash water contained in the filtrate tank 8 is recycled via a transfer line 9 into the intermediate repulper 10 which repulps a pulp mat 2' formed on a secondary vacuum drum filter 4' for feeding onto the tertiary vacuum filter 4. The remainder of the wash water transferred from the filtrate tank 8 is recycled via a transfer line 9' to be used to wash the pulp mat formed on the surface of the secondary vacuum drum filter 4' and is dispensed on the mat 2 via a wash spray 1'. The secondary vacuum drum filter 4' removes most of the water from the pulp mat formed on its surface and transfers the water via a transfer line 12 into a filtrate tank 8'.
Most of the wash water contained in filtrate tank 8' is recycled via a transfer line 14 into the intermediate repulper 10' which repulps the pulp mat formed on a primary vacuum drum filter 4" for feeding onto the secondary vacuum drum filter 4'. The remainder of the wash water transferred from the filtrate tank 8' is recycled via a transfer line 14' to be used to wash a pulp mat 2" formed on the surface of the primary vacuum drum filter 4", and is dispensed on the pulp mat 2" via the wash sprayer 1".
The primary vacuum drum filter 4" removes some of the water from the pulp mat on its surface and transfers this water into the filtrate tank 8" via a transfer line 16.
Some of the water in the filtrate tank 8" is added via a transfer line 18 to pulp and liquor supplied via a transfer line 20 from pulp digesters (not shown) for introduction of a pulp slurry into the primary vacuum drum filter 4". The remainder of the water from the filtrate tank 8" is transferred to evaporators via a transfer line 22.
The improvement of the present invention in relation to the countercurrent washing operation as described in FIG. 1, resides in a control apparatus shown in FIGS. 2, 3 and 4 which demonstrate the location of the control apparatus in relation to the rotary drum vacuum filter 4 as used in the washing operation described in FIG. 1.
The countercurrent flow wash system as illustrated in part by the tertiary rotary drum vacuum filter 4 in FIG. 2 shows the entry of fresh shower water into the system via a displacement wash sprayer 1. The fresh water is dispensed by wash sprayer 1 onto the thin pulp mat 2 which is formed from a pulp slurry 34. The pulp mat 2 travels over the exposed surface 3 of a rotary-drum vacuum filter 4 in the direction of the shown arrow. The wash sprayer 1 is designed to apply a uniform application of fresh shower water in order to achieve a high degree of displacement ratio. Wier type showers are sometimes used in place of or in conjunction with spray showers. The water content per unit area of the pulp on the drum filter is measured using a capacitance measurement apparatus 6 as the pulp mat 2 travels over the discharge side of the drum filter 4 and is between a vacuum break 5 and a discharge roller 38.
The capacitance measurement apparatus 6 performs an accurate measurement of the liquid content, that is, the water per square meter in the pulp mat 2 being discharged from the drum filter 4. When the surface 3 of the drum filter 4 is made of metal, the capacitance measurement apparatus may consist of only one live probe 7 using the drum filter surface 3 as the other plate of the capacitance circuit which becomes the grounded electrode. Where the filter drum is not metal, an additional capacitance electrode plate 40 must be stationed between the filter drum surface 3 and the rotating pulp mat 2. The live probe 7 should be spaced from the drum filter surface 3 such that the pulp mat 2 forms a substantial portion of the dielectric medium between the live probe 7 and the grounded electrode.
Capacitance measurement of the water content of the web is used to permit greater immediate control of the washing system. After determining the water content of the pulp mat exiting the washing system, a desired dilution factor is used to adjust the shower flow.
Capacitance measurement is used to determine the water content of the pulp mat for the following reasons. Water has a dielectric constant of 80 at 21° C., paper pulp has a dielectric constant of about 3, and air has a dielectric constant of 1. A pulp mat leaving a washer consists of 85 to 90 percent water and 10 to 15 percent pulp. A capacitance measurement alone at these conditions cannot be used to determine the percentage of pulp or water in the mat even if the mat were freely suspended from the washer drum due to the very low dielectric constant of pulp compared to water. For the same reason a capacitance measurement of a pulp mat containing 85 to 90 percent of water will measure essentially the water alone.
Capacitance measurement of the water content is determined in the following manner. The capacitance is measured using the formula in Equation I:
C=0.0886 KA/t (I)
where:
C=capacitance in picofarads (pF)
K=dielectric constant of the pulp mat
A=area of plates in square centimeters
t=spacing between plates in centimeters
It is well known that the dielectric constant of water which is the predominant factor effecting the dielectric constant of the pulp web, is variable with temperature. The dielectric constant of water at 100° C. is 55.33 and increases to 88.00 at 0° C.
This effect is compensated by temperature measurement of the pulp mat in the system. In most pulp washing processes the temperature of the washing water is held fairly constant and will not require a measurement of the temperature in the pulp mat itself. A normal temperature for the shower water is about 65° C. At a dilution factor exceeding 1.0, the temperature of the water in the mat is very nearly 65° C. A variation of 5° C. in the temperature of the water in the mat would produce an error of 2.3 percent in the measured amount of water in the mat. In instances where the water in the pulp mat has this degree of variability, the temperature should be constantly measured and the dielectric constant must be determined for use in Equation I.
A preselected frequency will be used in measuring the capacitance, however, the use of multiple frequencies for more accurate determination of the water content is possible and could be done in systems requiring greater accuracy than single frequency determinations.
Once the capacitance is determined, the water content in the discharging pulp mat as herein expressed in the terms liters of water per square meter of pulp mat may be expressed by Equation II.
L=CF (II)
where:
L=liters of water per square meter
C=capacitance of pulp mat in picofarads (pF)
F=cell factor
The cell factor F of the capacitor predetermined by a calibration test using Equation IIA:
F=B/V (IIA)
where:
V=meter reading in picofarads when a prepared sample is in the capacitor
B=water content of the prepared sample above in liters per square meter.
This calibration of the capacitor and determination of the cell factor is performed by measuring the capacitance of air in the capacitance measuring apparatus and subsequently measuring the capacitance of a prepared sample of pulp mixed with water in a known proportion.
After determining the liquid content L, the set point for the shower water flow on the washer may be calculated by Equation III with the variables expressed in appropriate units:
S=(L)(R)(A)(D) (III)
where:
S=shower flow set point (liters/minute)
L=liters of water per square meter
R=revolutions of the filter drum per minute
A=area of drum face surface in square meters
D=dilution factor
In the use of Equation III it should be noted that the area A of the filter drum surface 3 is completely covered with pulp mat as the drum makes one complete revolution and thus represents the area of pulp mat on the surface of the filter drum.
The capacitance measurement apparatus 6 is shown in alternative forms in FIG. 3 and FIG. 4.
In FIG. 3 the live capacitance plate 50 mechanically tranverses across the surface of the pulp mat 2. The transverse movement of the live plate 50 is performed by the rotation of a screw bar 52 through a threaded opening 54 in a plate assembly 55. The screw bar is rotated by a reversible electric motor 56. The plate assembly 55 is held in a vertical position through the use of a pair of guide rods 58. The live plate 50 transverses back and forth across the pulp mat on the drum filter 4 measuring the capacitance of the pump mat 2 using the metallic surface of the drum filter 4 as the grounded electrode while moving the transversing live capacitance plate 50 remains at the same relative distance between the vacuum break 5 and the pulp mat discharge on roller 38. The function of the transversing live plate 50 is to obtain capacitance readings along the entire width of the pulp mat.
In FIG. 4, a series of stationary live capacitance plates 60 are used to measure the capacitance along the width of a pulp mat 2 which rotates with the drum filter 4 and the metallic surface 3 of the filter drum acts as the grounded electrode. The plates 60 are located on a support 62 and controlled by an electrical switching device 64 which can activate any one of the individual plates 60 or any combination of the plates 60 to record either the capacitance at an individual plate position or take an average capacitance reading from two or more of the plates when a plurality of plates are activated.
The capacitance measurement apparatus has heretofore been illustrated as being located only on the tertiary drum filter 4 in the series of filter drums which are used in the countercurrent washing operation as shown in FIG. 1. However, it is obvious to one skilled in the art that it is advantageous to control the shower flow on all of the filter drums to increase the efficiency of the over-all wash system. As represented in FIG. 1, it is noted that the flow of liquid dispensed from the filtrate tank 8 via the transfer lines 9 and 9' is equal to the input into the filtrate tank 8 via the transfer line 5 from the tertiary drum filter 4. The level of liquid in the filtrate tank 8 must remain constant or the wash system will either overflow liquid from the filtrate tank 8 or stop due to a shortage of liquid supply to the transfer lines 9 and 9' from the filtrate tank 8. Since the filtrate tank 8 contains a large capacity of liquid compared to the flow through the wash sprayer 1' it is practical to regulate the liquid flow through the wash sprayer 1' onto the pulp mat 2' formed on the secondary rotary drum vacuum filter 4' through the use of the same capacitance measurement technique as is used on the tertiary rotary drum vacuum filter 4. One problem which arises in using the same capacitance measurement technique is that a slight change in conditions such as pulp consistency in the washing operations will cause a net gain or loss in the liquid level in the filtrate tank 8. This problem is overcome through the use of an additional dilution control system 66 as shown in FIG. 1 which slowly alters the dilution factor up or down to maintain a constant liquid level in the filtrate tank 8. The dilution control system 66 may consist of a flow regulator 67 which is responsive to a liquid level sensor 68 which records the level of the liquid in the filtrate tank 8 and correspondingly adjusts the flow rate of liquid to the wash sprayer 1'.
The shower flow through the wash sprayer 1" on the primary rotary drum vacuum filter 4" is controlled in the same manner using a dilution control system 69 to regulate the liquid level in the filtrate tank 8'.
These combined methods of controlling the shower flow from the wash sprayers 1, 1' and 1" onto their respective pulp mats 2,2' and 2" produces additional benefits in efficiency over excercising a control of the shower flow from the wash sprayer 1 alone in that a short term excessive wash will not compensate for an equal term of underwash in a previous washing stage. Neither the control of the shower flow nor the control of the liquid level in the filtrate tank either alone or in combination can be used to control the dilution factor without the capacitance measurements proposed herein. Additionally, through the use of the dilution control systems 66 and 69 in the countercurrent pulp washing operation an added benefit is obtained in the early detection of faulty equipment as filtrate tank levels will be responsive to abnormal deviations in the washing operation.
While the use of capacitance measurement apparatus appears to be the most accurate method of measuring the water content per unit area of the pulp mat on the filter drum, alternative systems may be used either alone or in combination with the capacitance measuring apparatus.
The first alternative system is shown in FIG. 5. A radiation source 76 transmits radiation which passes through the pulp mat 2 and strikes the metallic surface 3 of the filter drum 4 whereby radiation is reflected and detected by a radiation detector 78. This system will measure the total mass per unit area of the pulp mat and is located in a position to monitor the pulp mat 2 after the pulp mat rotates on the filter drum 4 over the vacuum break 5. In some cases this backscatter nuclear radiation device can be used alone and will give a better control than previously used since only the consistency need be estimated rather than an estimated rate determined from the first washer feed rate along with the consistency.
The second alternative system is essentially the same as the nuclear radiation system except that the nuclear source 76 is replaced with a microwave source 80 and the radiation detector 78 is replaced with a microwave sensor 82. With very sophisticated equipment and scanning microwave frequencies it is possible to determine both the dielectric losses and the water per unit area with this system.
The function of shower water control is so important that it may be desirable to use the capacitance measurement apparatus in conjunction with one of the alternative embodiments. The capacitance measurement is used to determine the water content per unit area in the pulp web and the radiation absorption measurement techniques can determine the total mass of the pulp mat per unit area.
Through the combined use of the measurements as calculated from capacitance measurement apparatus and from either radiation or microwave absorption measurement apparatus, the following parameters of a pulp wash system may be calculated from their respective determination equations.
Equation IV may be used to calculate the dry pulp mass per unit area in the pulp mat employing both the total mass of pulp and water per unit area, as determined by radiation measurement techniques and the mass of water per unit area of the pulp mat as determined by capacitance measurement:
P=M-LG (IV)
where:
P=kilograms of pulp per square meter of pulp mat
M=kilograms of pulp and water per square meter of pulp mat
L=liters of water per square meter of pulp mat
G=specific gravity of water at existing conditions such as the temperature of the pulp mat
The pulp production rate of a pulp washing system is determined by Equation V:
Q=1.44(P)(R)(A) (V)
where:
Q=pulp production rate in metric tons per day
P=kilograms of pulp per square meter of pulp mat
R=revolutions per minute of filter drum
A=area of surface of filter drum in square meters
The consistency or the percentage of pulp in the mixture of pulp and water leaving the wash system in the form of a pulp mat is calculated by equation VI:
N=100P/M (VI)
where:
N=consistency of pulp mat expressed in percentage
P=kilograms of dry pulp per square meter of pulp mat
M=kilograms of pulp and water per square meter of pulp mat
Conventional thickness measuring apparatus may be employed in a pulp washing system as demonstrated by thickness measuring device 88 in FIG. 5 which determines the pulp mat thickness at a point between the vacuum break 5 and roller discharge 38. The air content of the mat may be determined by Equation VII through the use of the combined measurements of the apparatus demonstrated in FIG. 5. The percentage of air entrained in the pulp effects the displacement factor.
U=100-10(L+(P/G))/T (VII)
where:
U=percentage of air in pulp mat
L=liters of water per square meter of pulp mat
P=kilograms of dry pulp per square meter of pulp mat
G=specific gravity of cellulose
T=thickness of pulp mat in centimeters
Some pulp washing systems employ chemical additives to improve the overall washing operation. These additives perform a variety of functions such as prevention of foaming and air entrainment in the pulp slurry and include anti-foam agents, drainage aids and washing aids. The measurement and determination of the pulp consistency and the air content of the pulp mat can be used to minimize the amount of the above-identified additives which are added to the washing operation.
While the present invention has been described in the context of a basic brown stock pulp washing operation for washing cellulose, it may be applied to a variety of operations such as a bleach plant washing step. The liquid dispensed from the wash sprayers may be water, recycled water or chemical treating agents. The control system is applicable to systems which treat slurries of materials other than pulp such as lime mud feed to kilns or calciners.
It is, of course, understood that the foregoing description of the process of the present invention is intended to be illustrative and that modifications thereof as would be apparent to one skilled in the art are deemed to fall within the scope and spriit of the present invention as defined by the following claims. | A method of controlling the amount of a liquid shower flow introduced onto a slurry mat such as a pulp mat which is undergoing incomplete liquid separation on a vacuum filter drum. The flow rate of the liquid being discharged with the slurry mat is determined by a capacitance measurement which is taken after the slurry mat has passed to a point on the filter means where liquid separation no longer occurs. The shower flow is controlled by a correlation of the flow rate of the liquid in the slurry mat with the rate of slurry mat transfer from the vacuum filter drum and the necessary liquid shower flow as expressed by a dilution factor.
The present control system may be combined with secondary apparatus to measure the flow rate and thickness of the total slurry mat in order to determine by correlation the slurry mat consistency, the rate of solid material production from the slurry mat and the amount of air contained in the slurry mat. | 3 |
[0001] This application claims priority to Chinese Patent Application No. 200710019110.2, filed with the Chinese Patent Office on Nov. 19, 2007 and entitled “Block cipher algorithm based Encryption processing device”, which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to the field of information security and in particular to an encryption processing method based upon a block cipher algorithm.
BACKGROUND OF THE INVENTION
[0003] Block cipher algorithms generally include a Data Encryption Standard (DES) algorithm, a tri-DES (3DES) algorithm, an Advanced Encryption Standard (AES) algorithm, an International Data Encryption Algorithm (IDEA), an SMS4 algorithm published by the State Secret Code Regulatory Commission Office, etc. Key components implementing a block cipher algorithm include a key expansion unit, an encryption unit and a sub-key array storage unit. Particularly, internal structures of the key expansion unit and the encryption unit are similar in that they generally consist of a data register component and a data conversion component.
[0004] The data register component is generally implemented with a general flip flop to register data. Data registered in this component is invariant in a clock cycle. The general flip flop is a data register device in which data at a data input is transmitted to an output of the flip flop at a rising or falling edge of a clock and the data at the output of the flip flop is invariant at other instances of time.
[0005] The data conversion component is a component to process data as required in the block cipher algorithm, e.g., a component to process data as required in the national SMS4 cipher algorithm. Operations performed by the data conversion component include only one integration and permutation as specified in the cipher algorithm.
[0006] The sub-key array storage unit is adapted to store an array of sub-keys. An array of sub-keys in the existing technology is typically an array of data already prepared prior to encryption and decryption and generated by the key expansion unit. In the SMS4 cipher algorithm, data of the sub-key array storage unit is arranged in a descending/ascending order of addresses and can be named rk0, rk1, rk31.
[0007] A current process of encrypting and decrypting data as required in the SMS4 cipher algorithm includes two separate phases of expanding a key and encrypting data. As illustrated in FIG. 1 , firstly a key expansion unit expands a key into an array of sub-keys and stores them sequentially into a sub-key array storage unit, and then an encryption unit encrypts data using the array of sub-keys into which the key is expanded.
[0008] A. The phase of expanding a key:
[0009] 1) An external key is input to a data register component of a key expansion unit.
[0010] An external key subject to preliminary processing is input to a data register component 100 of a key expansion unit for registering.
[0011] 2) Conversion of data.
[0012] The data registered in the data register component 100 of the key expansion unit is input to a data conversion component 101 of the key expansion unit for conversion to result in sub-keys.
[0013] 3) Iterative Processing of the Data.
[0014] Data resulting from previous conversion is stored in the data register component 100 of the key expansion unit while the resulting sub-keys are stored in a first line of a sub-key array storage unit 2 , and then the data registered in the data register component 100 of the key expansion unit is input again to the data conversion component 101 of the key expansion unit for conversion and resulting sub-keys are stored in a next line of the sub-key array storage unit 2 . This process of converting the data is repeated for thirty-two times to result in an array of sub-keys of 32×32 bits=1024 bits.
[0015] B. The Phase of Encrypting the Data:
[0016] 1) External data is input to a data register component of an encryption unit.
[0017] External data is input to a data register component 300 of an encryption unit for registering.
[0018] 2) Conversion of the Data.
[0019] The data registered in the data register component 300 of the encryption unit is input to a data conversion component 301 of the encryption unit, and the data corresponding to the first line of the array of sub-keys stored in the sub-key array storage unit 2 is input to the data conversion component 301 of the encryption unit for conversion.
[0020] 3) Iterative Processing of the Data.
[0021] Data resulting from previous conversion is stored in the data register component 300 of the encryption unit, and then the data registered in the data register component 300 of the encryption unit is input again to the data conversion component 301 of the encryption unit for conversion and also the next line of sub-keys of the sub-key array storage unit 2 are input to the data conversion component 301 of the encryption unit for conversion of the data. This process is repeated for thirty-two times to result in data.
[0022] It takes thirty-two clock cycles in the foregoing encryption algorithm to process a set of data with low efficiency. In order to improve this circumstance, the processing efficiency can be improved with an increased number of data conversion components. For example, a set of 128-bit data can be processed in sixteen clock cycles as illustrated in FIG. 2 .
[0023] A sub-key array storage component is an indispensable component in the existing technology. If a 1024-bit sub-key array storage component is implemented with a register in an integrated circuit, then a logic resource of approximately ten thousands gates, which occupies approximately 40% of a total resource (a total resource of approximately twenty-five thousands gates is consumed in the solution of FIG. 1 ) will be consumed at a high cost.
SUMMARY OF THE INVENTION
[0024] An object of the invention is to provide an inexpensive and efficient encryption processing method based upon a block cipher algorithm so as to address the technical problem of a high cost of the encryption processing method based upon a block cipher algorithm in the existing technology.
[0025] A technical solution of the invention is as follows.
[0026] An encryption processing device based upon a block cipher algorithm includes a key expansion unit and an encryption unit, wherein:
the key expansion unit includes a data register component of the key expansion unit and at least one data conversion component of the key expansion unit, the encryption unit includes a data register component of the encryption unit and at least one data conversion component of the encryption unit, the number of data conversion components of the encryption unit is identical to the number of data conversion components of the key expansion unit, and the data conversion components of the encryption unit are in one-to-one connection with the data conversion components of the key expansion unit; an output of the data register component of the key expansion unit is connected with an input of the first one of the data conversion components of the key expansion unit, every two adjacent ones of the data conversion components of the key expansion unit are connected sequentially, and an output of the last one of the data conversion components of the key expansion unit is connected with an input of the data register component of the key expansion unit; an output of the data register component of the encryption unit is connected with an input of the first one of the data conversion components of the encryption unit, every two adjacent ones of the data conversion components of the encryption unit are connected sequentially, and an output of the last one of the data conversion components of the encryption unit is connected with an input of the data register component of the encryption unit; a sub-key output of each of the data conversion components of the key expansion unit is connected with a sub-key input of the corresponding one of the data conversion components of the encryption unit; the data register component of the expansion unit is adapted to register an input external key and data resulting from the last one of the data conversion components of the key expansion unit; the data conversion component of the key expansion unit is adapted to receive the data registered in the data register component of the key expansion unit to expand the key into sub-keys input to the corresponding data conversion component of the encryption unit; the data register component of the encryption unit is adapted to register input external data and data resulting from the last one of the data conversion components of the encryption unit; and the data conversion component of the encryption unit is adapted to receive the data registered in the data register component of the encryption unit and to encrypt and convert the received data using the sub-keys resulting from the corresponding data conversion component of the key expansion unit.
[0035] The invention has the following advantages.
[0036] 1. The encryption processing device according to the invention can effectively reduce a consumed resource and hence a cost of the device while maintaining efficiency of the existing technology because a sub-key array storage unit is dispensed with.
[0037] 2. With the encryption processing device according to the invention, a consumed resource is only 60% of that in the existing technology in the case of one conversion component and 70% of that in the existing technology in the case of two conversion components.
[0038] 3. Since the sub-key register unit is added, a crucial path can be shortened in an integrated circuit to increase a primary frequency of a clock of and hence the processing capability of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a schematic diagram illustrating a first structure of an encryption and decryption processing device in the existing technology;
[0040] FIG. 2 is a schematic diagram illustrating a second structure of an encryption and decryption processing device in the existing technology;
[0041] FIG. 3 is a schematic diagram illustrating a first structure of an encryption and decryption processing device according to the invention;
[0042] FIG. 4 is a schematic diagram illustrating a second structure of an encryption and decryption processing device according to the invention;
[0043] FIG. 5 is a schematic diagram illustrating a third structure of an encryption and decryption processing device according to the invention; and
[0044] FIG. 6 is a schematic diagram illustrating a fourth structure of an encryption and decryption processing device according to the invention.
[0045] Herein, 1 denotes a key expansion unit, 100 denotes a data register component of the key expansion unit, 101 ( 101 a , 101 b ) denotes a data conversion component of the key expansion unit, 2 denotes a sub-key array storage unit, 3 denotes an encryption unit, 300 denotes a data register component of the encryption unit, 301 ( 301 a , 301 b ) denotes a data conversion component of the encryption unit, 4 denotes a sub-key register unit, and 401 ( 401 a , 401 b ) denotes a sub-key register component.
DETAILED DESCRIPTION OF THE INVENTION
[0046] Now a device according to the invention will be detailed below with reference to the drawings.
The First Embodiment
[0047] As illustrated in FIG. 3 , a first encryption processing device based upon a block cipher algorithm includes a key expansion unit 1 and an encryption unit 3 .
[0048] The key expansion unit 1 includes a data register component 100 of the key expansion unit and a data conversion component 101 of the key expansion unit, an output of the data register component 100 of the key expansion unit is connected with an input of the data conversion component 101 of the key expansion unit, and an output of the data conversion component 101 of the key expansion unit is connected with an input of the data register component 100 of the key expansion unit.
[0049] The encryption unit 3 includes a data register component 300 of the encryption unit and a data conversion component 301 of the encryption unit, an output of the data register component 300 of the encryption unit is connected with an input of the data conversion component 301 of the encryption unit, and an output of the data conversion component 301 of the encryption unit is connected with an input of the data register component 300 of the encryption unit.
[0050] Particularly, a sub-key output of the data conversion component 101 of the key expansion unit is connected with a sub-key input of the data conversion component 301 of the encryption unit.
[0051] Referring to FIG. 3 , the first encryption processing device based upon a block cipher algorithm performs the following steps of a method according to an embodiment of the invention.
[0052] 1] An external key is registered: a processed external key is input to the data register component 100 of the key expansion unit for registering upon arrival of a clock edge of a clock cycle.
[0053] 2] External data is registered: a set of external data is input to the data register component 300 of the encryption unit for registering upon arrival of the clock edge of the clock cycle.
[0054] 3] The key is expanded: in the clock cycle, the data registered in the data register component 100 of the key expansion unit is input to the data conversion component 101 of the key expansion unit to expand the key into sub-keys input to the data conversion component 301 of the encryption unit.
[0055] 4] The data is encrypted and converted: in the clock cycle, the data registered in the data register component 300 of the encryption unit is input to the data conversion component 301 of the encryption unit, which in turn encrypts and converts the data.
[0056] 5] The internal data is registered: upon arrival of a clock edge of a next clock cycle, data resulting from the data conversion component 101 of the key expansion unit is input to the data register component 100 of the key expansion unit for registering, and data resulting from the data conversion component 301 of the encryption unit is input to the data register component 300 of the encryption unit for registering.
[0057] 6] The data is processed iteratively: the step of expanding the key, the step of encrypting and converting the data, and the step of registering the internal data are repeated until the data is converted for a number of times as specified in the block cipher algorithm, and then encryption of the set of data is completed.
The Second Embodiment
[0058] As illustrated in FIG. 4 , a second encryption processing device based upon a block cipher algorithm includes a key expansion unit 1 and an encryption unit 3 .
[0059] The key expansion unit 1 includes a data register component 100 of the key expansion unit and two data conversion components 101 a and 101 b of the key expansion unit, an output of the data register component 100 of the key expansion unit is connected with an input of the first data conversion component 101 a of the key expansion unit, the two data conversion components 101 a and 101 b of the key expansion unit are connected sequentially, and an output of the second data conversion component 101 b of the key expansion unit is connected with an input of the data register component 100 of the key expansion unit.
[0060] The encryption unit 3 includes a data register component 300 of the encryption unit and two data conversion components 301 a and 301 b of the encryption unit, an output of the data register component 300 of the encryption unit is connected with an input of the first data conversion component 301 a of the encryption unit, the two data conversion components 301 a and 301 b of the encryption unit are connected sequentially, and an output of the second data conversion component 301 b of the encryption unit is connected with an input of the data register component 300 of the encryption unit.
[0061] Particularly, a sub-key output of the first data conversion component 101 a of the key expansion unit is connected with a sub-key input of the first data conversion component 301 a of the encryption unit, and a sub-key output of the second data conversion component 101 b of the key expansion unit is connected with a sub-key input of the second data conversion component 301 b of the encryption unit.
[0062] Particularly, the number of data conversion components of the key expansion unit is identical to the number of data conversion components of the encryption unit can be three, four and up to thirty-two or forth-eight, preferably one, two or four.
[0063] Referring to FIG. 4 , the second encryption processing device based upon a block cipher algorithm performs the following steps of a method according to an embodiment of the invention.
[0064] 1] An external key is registered: a processed external key is input to the data register component 100 of the key expansion unit for registering upon arrival of a clock edge of a clock cycle.
[0065] 2] External data is registered: a set of external data is input to the data register component 300 of the encryption unit for registering upon arrival of the clock edge of the clock cycle.
[0066] 3] The key is expanded: in the clock cycle, the data registered in the data register component 100 of the key expansion unit is input to the data conversion component 101 a of the key expansion unit to expand the key into sub-keys input to the data conversion component 301 a of the encryption unit, and data output from the data conversion component 101 a of the key expansion unit is input to the next data conversion component 101 b of the key expansion unit, so that the data conversion components of the key expansion unit expand the key sequentially.
[0067] 4] The data is encrypted and converted: in the clock cycle, the data registered in the data register component 300 of the encryption unit is input to the data conversion component 301 a of the encryption unit, which in turn encrypts and converts the data, and data output from the data conversion component 301 a of the encryption unit is input to the next data conversion component 301 b of the encryption unit, so that the data conversion components of the encryption unit encrypt the data sequentially.
[0068] 5] The internal data is registered: upon arrival of a clock edge of a next clock cycle, data output from the last data conversion component ( 101 b in the present embodiment) of the key expansion unit is input to the data register component 100 of the key expansion unit for registering, and data output from the last data conversion component ( 301 b in the present embodiment) of the encryption unit is input to the data register component 300 of the encryption unit for registering.
[0069] 6] The data is processed iteratively: the step of expanding the key, the step of encrypting and converting the data, and the step of registering the internal data are repeated until the data is converted for a number of times as specified in the block cipher algorithm, and then encryption of the set of data is completed.
The Third Embodiment
[0070] As illustrated in FIG. 5 , a third encryption processing device based upon a block cipher algorithm includes a key expansion unit 1 , a sub-key register unit 4 and an encryption unit 3 .
[0071] The key expansion unit 1 includes a data register component 100 of the key expansion unit and a data conversion component 101 of the key expansion unit, an output of the data register component 100 of the key expansion unit is connected with an input of the data conversion component 101 of the key expansion unit, and an output of the data conversion component 101 of the key expansion unit is connected with an input of the data register component 100 of the key expansion unit.
[0072] The sub-key register unit 4 includes a sub-key register component 401 which may be a general flip flop or register.
[0073] The encryption unit 3 includes a data register component 300 of the encryption unit and a data conversion component 301 of the encryption unit, an output of the data register component 300 of the encryption unit is connected with an input of the data conversion component 301 of the encryption unit, and an output of the data conversion component 301 of the encryption unit is connected with an input of the data register component 300 of the encryption unit.
[0074] Particularly, a sub-key output of the data conversion component 101 of the key expansion unit is connected with an input of the sub-key register component 401 , and an output of the sub-key register component 401 is connected with a sub-key input of the data conversion component 301 of the encryption unit.
[0075] Referring to FIG. 5 , the third encryption processing device based upon a block cipher algorithm performs the following steps of a method according to an embodiment of the invention.
[0076] 1] An external key is registered: a processed external key is input to the data register component 100 of the key expansion unit for registering upon arrival of a clock edge of a clock cycle.
[0077] 2] A key is pre-expanded: in a clock cycle in which the external key is registered, data registered in the data register component 100 of the key expansion unit is input to the data conversion component 101 of the key expansion unit to expand the key into sub-keys input to the input of the sub-key register component 401 connected therewith, and data resulting from the data conversion component 101 of the key expansion unit is input to the input of the data register component 100 of the key expansion unit.
[0078] 3] The key is buffered and registered: upon arrival of a clock edge of a next clock cycle after the step of registering the external key, data resulting from the data conversion component 101 of the key expansion unit is input to the data register component 100 of the key expansion unit for registering, and the sub-keys of the data conversion component 101 of the key expansion unit are input to the sub-key register component 401 for registering.
[0079] 4] The external data is registered: a set of external data is input to the data register component 300 of the encryption unit for registering upon arrival of the clock edge of the next clock cycle after the step of registering the external key.
[0080] 5] The key is expanded: in the clock cycle, the data registered in the data register component 100 of the key expansion unit is input to the data conversion component 101 of the key expansion unit to expand the key into sub-keys input to the input of the sub-key register component 401 connected therewith, data output from the data conversion component 101 of the key expansion unit is input to the input of the data register component 100 of the key expansion unit, and the sub-keys output from the sub-key register component 401 are input to the data conversion component 301 of the encryption unit.
[0081] 6] The data is encrypted and converted: in the clock cycle, the data registered in the data register component 300 of the encryption unit is input to the data conversion component 301 of the encryption unit, which in turn encrypts and converts the data, and data output from the data conversion component 301 of the encryption unit is input to the input of the data register component 300 of the encryption unit.
[0082] 7] The internal data is registered: upon arrival of a clock edge of a next clock cycle, data resulting from the data conversion component 101 of the key expansion unit is input to the data register component 100 of the key expansion unit for registering, the sub-keys of the data conversion component 101 of the key expansion unit are input to the sub-key register component 401 for registering, and data resulting from the data conversion component 301 of the encryption unit is input to the data register component 300 of the encryption unit for registering.
[0083] 6] The data is processed iteratively: the step of expanding the key, the step of encrypting and converting the data, and the step of registering the internal data are repeated until the data is converted for a number of times as specified in the block cipher algorithm, and then encryption of the set of data is completed.
The Fourth Embodiment
[0084] As illustrated in FIG. 6 , a fourth encryption processing device based upon a block cipher algorithm includes a key expansion unit 1 , a sub-key register unit 4 and an encryption unit 3 .
[0085] The key expansion unit 1 includes a data register component 100 of the key expansion unit and two data conversion components 101 a and 101 b of the key expansion unit, an output of the data register component 100 of the key expansion unit is connected with an input of the first data conversion component 101 a of the key expansion unit, the two data conversion components 101 a and 101 b of the key expansion unit are connected sequentially, and an output of the second data conversion component 101 b of the key expansion unit is connected with an input of the data register component 100 of the key expansion unit.
[0086] The sub-key register unit 4 includes two sub-key register components 401 a and 401 b which may be a general flip flop or register.
[0087] The encryption unit 3 includes a data register component 300 of the encryption unit and two data conversion components 301 a and 301 b of the encryption unit, an output of the data register component 300 of the encryption unit is connected with an input of the first data conversion component 301 a of the encryption unit, the two data conversion components 301 a and 301 b of the encryption unit are connected sequentially, and an output of the second data conversion component 301 b of the encryption unit is connected with an input of the data register component 300 of the encryption unit.
[0088] Particularly, a sub-key output of the first data conversion component 101 a of the key expansion unit is connected with an input of the first sub-key register component 401 a , and an output of the first sub-key register component 401 a is connected with a sub-key input of the first data conversion component 301 a of the encryption unit; and a sub-key output of the second data conversion component 101 b of the key expansion unit is connected with an input of the second sub-key register component 401 b , and an output of the second sub-key register component 401 b is connected with a sub-key input of the second data conversion component 301 b of the encryption unit.
[0089] Particularly, the number of data conversion components of the key expansion unit, the number of sub-key register components and the number of data conversion components of the encryption unit are identical and can be three, four and up to thirty-two or forth-eight, preferably one, two or four.
[0090] Referring to FIG. 6 , the fourth encryption processing device based upon a block cipher algorithm performs the following steps of a method according to an embodiment of the invention.
[0091] 1] An external key is registered: a processed external key is input to the data register component 100 of the key expansion unit for registering upon arrival of a clock edge of a clock cycle.
[0092] 2] A key is pre-expanded: in a clock cycle in which the external key is registered, data registered in the data register component 100 of the key expansion unit is input to the first data conversion component 101 a of the key expansion unit to expand the key into sub-keys input to the input of the first sub-key register component 401 a connected therewith, and data output from the first data conversion component 101 a of the key expansion unit is input to the input of the next data register component 101 b of the key expansion unit to expand the key for the second time, so that the data conversion components of the key expansion unit expand the key sequentially into sub-keys input to the inputs of the respective sub-key register components connected therewith, and data output from the last data conversion component ( 101 b in the present embodiment) of the key expansion unit is input to the input of the data register component 100 of the key expansion unit.
[0093] 3] The key is buffered and registered: upon arrival of a clock edge of a next clock cycle after the step of registering the external key, data resulting from the last data conversion component ( 101 b in the present embodiment) of the key expansion unit is input to the data register component 100 of the key expansion unit for registering, and the sub-keys of the data conversion components of the key expansion unit are input to the sub-key register components corresponding thereto for registering.
[0094] 4] The external data is registered: a set of external data is input to the data register component 300 of the encryption unit for registering upon arrival of the clock edge of the next clock cycle after the step of registering the external key.
[0095] 5] The key is expanded: in the clock cycle, the data registered in the data register component 100 of the key expansion unit is input to the first data conversion component 101 a of the key expansion unit to expand the key into sub-keys input to the input of the first sub-key register component 401 a connected therewith, and data output from the first data conversion component 101 a of the key expansion unit is input to the input of the next data register component 101 b of the key expansion unit to expand the key for the second time, so that the data conversion components of the key expansion unit expand the key sequentially into sub-keys input to the inputs of the respective sub-key register components connected therewith, and data output from the last data conversion component ( 101 b in the present embodiment) of the key expansion unit is input to the data input of the data register component 100 of the key expansion unit.
[0096] 6] The data is encrypted and converted: in the clock cycle, the data registered in the data register component 300 of the encryption unit is input to the first data conversion component 301 a of the encryption unit, and the sub-keys of the first sub-key register component 401 a are input to the first data conversion component 301 a of the encryption unit, which in turn encrypts and converts the data; and the encrypted and converted data from the first data conversion component 301 a of the encryption unit is input to the second data conversion component 301 b of the encryption unit, and the sub-keys of the second sub-key register component 401 b are input to the second data conversion component 301 b of the encryption unit, which in turn encrypts and converts the data, so that the data conversion components of the encryption unit corresponding to the data conversion components of the key expansion unit encrypt and convert the data sequentially, and data output from the last data conversion component ( 301 b in the present embodiment) of the encryption unit is input to the data input of the data register component 300 of the encryption unit.
[0097] 7] The internal data is registered: upon arrival of a clock edge of a next clock cycle, data resulting from the last data conversion component ( 101 b in the present embodiment) of the key expansion unit is input to the data register component 100 of the key expansion unit for registering, the sub-keys of the data conversion components of the key expansion unit are input to the sub-key register components corresponding thereto for registering, and data resulting from the last data conversion component ( 301 b in the present embodiment) of the encryption unit is input to the data register component 300 of the encryption unit for registering.
[0098] 8] The data is processed iteratively: the step of expanding the key, the step of encrypting and converting the data, and the step of registering the internal data are repeated until the data is converted for a number of times as specified in the block cipher algorithm, and then encryption of the set of data is completed.
[0099] If the encryption processing device is provided with a plurality of data conversion components of the key expansion unit, a plurality of sub-key register components, and a plurality of data conversion components of the encryption unit, then they expand the key and encrypt the data sequentially in the sequence in which they are connected.
[0100] If the SMS4 algorithm is particularly adopted as the block cipher algorithm, then the encryption method in the foregoing four embodiments converts the data iteratively particularly for thirty-two times. | A packet cipher algorithm based encryption processing device includes a key expand unit and an encryption unit. The key expand unit comprises a key expand unit data registration component and at least one key expand unit data conversion component. The encryption unit comprises an encryption unit data registration component and at least one encryption unit data conversion component, and the number of the encryption unit data conversion component is the same as that of the key expand unit data conversion component, and besides, they are one to one. A sub-key output of each key expand unit data conversion component connects the corresponding sub-key input of each encryption unit data conversion component to solve the technical problems that the encryption efficiency of the prior packet cipher algorithm based encryption processing device is low and the cost is high. The advantage of the present invention is reducing the resource consumption and further reducing the achievement cost of the device under the premise of keeping the high efficiency of the prior art. | 7 |
CROSS-REFERENCES TO RELATED APPLICATION
This subject matter of this application is related to the subject matter of U.S. patent application Ser. No. 60/134,277, filed May 14, 1999, priority to which is claimed under 35 U.S.C. § 119(e) and which is incorporated herein by reference.
BACKGROUND OF TIE INVENTION
1. Field of the Invention
The invention relates to portable containers for delivering food products, such as pizzas, from a central location to one or more remote locations. More specifically, the invention relates to pizza delivery bags constructed to maintain internal atmospheric characteristics, such as temperature and humidity, at desired levels.
2. Description of Related Art
Bags for enclosing and transporting food items, such as pizza, are known in the art. These bags typically accommodate one or more food items to be delivered to a delivery site at a remote location. The food items are usually packaged, e.g., in cardboard boxes, before being inserted into the bag. The bags are used primarily to keep the food products warm while enroute from where they are prepared to the delivery site.
U.S. Pat. No. 6,018,143, issued Jan. 25, 2000 to Check, and incorporated herein by reference, discloses a portable, thermal bag for containing a food product, such as pizza. The bag has top and bottom panels and is closed along both sides at the rear end. The front end of the bag is open to permit insertion and removal of the food product. The top and bottom panels each have an outer cover layer, an inner cover layer, and electric resistance wires between the cover layers. The resistance wires may be plugged into the cigarette lighter of a delivery vehicle to keep the food product warm. A thermostat is placed at the center of the top panel to control the temperature. The bag has a quick release connector, which may also be plugged into a low voltage transformer in a restaurant where several bags may be kept before being used to carry a pizza in a delivery vehicle.
U.S. Pat. No. 5,892,202, issued Apr. 6, 1999 to Baldwin et al., and incorporated herein by reference, discloses a carrying case for storing and transporting heated articles. The carrying case includes a thermal storage assembly having a heat retention member and a heating coil assembly. The heat retention member absorbs and retains sensible heat and releases the sensible heat for an extended time period.
U.S. Pat. No. 5,880,435, issued Mar. 9, 1999 to Bostic, and incorporated herein by reference, discloses a food delivery container. The food delivery container includes a heating element with a phase change material, such as an ultra-high molecular weight polyethylene. The ultra-high molecular weight polyethylene transforms from a solid to a semi-solid at approximately 248-275° F. The heating element includes a rigid envelope which is permeable to prevent gaseous build up during heating. The heating element, when placed within a suitable insulated container, will maintain food warm for several hours during storage or delivery. An electric resistance grid may be provided for supplying heat energy.
U.S. Pat. No. 5,676,051, issued Oct. 14, 1997 to Sinemus, and incorporated herein by reference, discloses a heated warming apparatus for food products. The apparatus includes one or a plurality of food containers, a housing, and a hot-air fan. The housing accommodates the food containers. The hot-air fan discharges air through a discharge opening in the housing. In order to maintain food products at a sufficiently high temperature, the hot air is heated extensively. However, the objective of reduced heating power expenditure is achieved by providing each food container with one or a plurality of inlet holes and one or a plurality of outlet holes. Each food container is arranged in the housing such that at least one of its holes is in fluid communication with the discharge opening.
U.S. Pat. No. 5,404,808, issued Apr. 11, 1995 to Smith et al., and incorporated herein by reference, discloses a carrier for hot food. In this carrier, a volume of dehumidifier material, such as calcium sulfate, is heated to a temperature greater than the pre-determined serving temperature of the food product and positioned in heat exchange relation with the food product, such that heat is transferred from the heated dehumidifier material to the food product and such that moisture is transferred from the food product to the dehumidifier material.
U.S. Pat. No. 5,078,050, issued Jan. 7, 1992 to Smith, and incorporated herein by reference, discloses a hot plate carrier. The carrier is disclosed as being for a partially baked dough product having a bottom crust and a moist topping. The carrier includes a vented container and a heater. The vented container contains the partially baked dough product. The heater is adapted to initially heat the bottom of the partially baked dough product to a temperature greater than 250° F. to finish baking the crust of the dough product and maintain the temperature of the crust greater than the temperature of the moist topping. The vented container is formed to exhaust moist air from the interior of the container while maintaining the temperature of air adjacent to the moist topping on the dough product at above the dew point of air in the container to prevent moisture condensation and to draw air from outside the container to expel moisture from adjacent the bottom crust.
U.S. Pat. No. 4,806,736, issued Feb. 21, 1989 to Schirico, and incorporated herein by reference, discloses a heated delivery bag (portable container) for heating and storing pizza. The heated delivery bag includes a fabric box about 20 inches long, about 20 inches wide, and about 8 inches high. The box is supported in its four vertical corners by plexi-glass strips positioned inside sleeves. A lower rigid panel is located at the bottom of the fabric box. The lower rigid panel is used to support a heating unit. An upper rigid panel located above the heating units forms a compartment with the sides and top of the fabric box large enough to contain two pizzas in their delivery box containers. The heating unit includes an aluminum pan. The aluminum pan contains a block of insulation with a ½ inch depression on its upper surface. A silicone rubber heating element is positioned inside this depression. The temperature inside the portable container is maintained at between 165-180° F. The portable container can be carried with one hand when used for delivering hot pizzas.
The devices referenced above generally are intended to transport food from a first location to a second location. However, devices according to the prior art are not believed to be constructed of materials that allow relative humidity within the bag to decrease in an optimal fashion or otherwise provide optimal humidity characteristics. Further, these devices suffer an inability to readily remove and/or replace heating elements associated therewith, e.g. during cleaning or in the event of heating element failure. Still further, none are believed to easily and inexpensively allow ready interchangeability of the heating elements, for use in more than one bag and/or in multiple locations. A need has arisen to address these and other problems.
SUMMARY OF THE INVENTION
Embodiments of the invention substantially meet the aforementioned and other needs of relevant industries by providing a portable container, e.g. a pizza delivery bag, and a method of use, in the manner described in this application.
According to one aspect of the invention, a portable container for transporting food comprises an enclosure, the enclosure having an openable section, the openable section being movable from an open position, in which food can be placed into the enclosure for transport and in which food can be removed from the enclosure, and a closed position. At least one pocket is connected to the enclosure, and at least one modular heating element is disposed within the at least one pocket. The at least one modular heating element is readily removable from the pocket for use in a different, generally identical portable container, and the at least one modular heating element provides thermal energy to food disposed within the enclosure.
The enclosure is constructed to allow passage of moisture therethrough, and/or to wick moisture from the inside of the enclosure to the outside of the enclosure. The at least one modular heating element is constructed to allow passage of moisture therethrough. The at least one modular heating element is powered by electricity, and further comprises a power cord extending out of the container for connection to a source of electricity. The container comprises a plurality of pockets connected to the enclosure, at least one modular heating element being disposed within each of the plurality of pockets, the modular heating elements being readily removable from the respective pockets.
According to another aspect of the invention, a method of transporting food in a portable container comprises providing an enclosure, the enclosure having an openable section, the openable section being movable from an open position, in which food can be placed into the enclosure for transport and in which food can be removed from the enclosure, and a closed position, moving the openable section to the open position, placing food within the enclosure for transport, providing at least one pocket connected to the enclosure and at least one modular heating element disposed within the at least one pocket, the at least one modular heating element being readily removable from the pocket, and providing thermal energy to food disposed within the enclosure with the at least one modular heating element. The method further includes removing the at least one modular heating element from the pocket, and placing the at least one modular heating element in a pocket of a different, generally identical portable container.
According to another aspect of the invention, a portable container for transporting food comprises means for enclosing food, the means for enclosing comprising means for opening such that food can be placed within the means for enclosing and can be removed from the means for enclosing, and means for accommodating modular means for heating, the means for accommodating being connected to the means for enclosing, the means for accommodating being constructed such that modular means for heating is readily removable from the means for accommodating for use in a different, generally identical portable container.
According to another aspect of the invention, a portable container for transporting food comprises an enclosure, the enclosure having an openable section, the openable section being movable from an open position, in which food can be placed into the enclosure for transport and in which food can be removed from the enclosure, and a closed position, and at least one heating element for providing thermal energy to food within the enclosure, wherein the enclosure is constructed to allow passage of moisture therethrough, further wherein the enclosure and the at least one heating element are constructed such that relative humidity within the enclosure decreases from about 100% at a first time point to between about 50% and about 60% at a time point about 40 minutes after the first time point while the openable section remains in the closed position.
According to another aspect of the invention, a portable container for delivering food comprises an upper panel, a lower panel, a rear panel, a first side panel, a second side panel, and a closing flap, wherein said rear panel, said first side panel and said second side panel all extend between said upper panel and said lower panel, further wherein at least said upper panel, said lower panel, said rear panel, said first side panel, and said second side panel all comprise a substantially flexible and moisture-permeable insulating panel material and all define interior and exterior surfaces, and a first pocket defining a first pocket opening and disposed proximate the interior surface of at least one of the upper, lower, rear, and first and second side panels.
A modular heating element preferably is disposed in the first pocket. The panel material and the heating element cooperate such that relative humidity within the container decreases from about 100% to between about 40% and about 60% over a time period of about 40 minutes while the closing flap is in a closed position. Additionally, the panel material and the heating element preferably cooperate such that temperature within the container decreases by no more than about 10 Fahrenheit degrees in a time period of about 40 minutes while the closing flap is in a closed position.
According to another aspect of the invention, the panel material and the heating element cooperate such that relative humidity within the container decreases from about 100% to between about 55% and about 70% over a time period of about 40 minutes while the closing flap is in a closed position. According to another aspect of the invention, the panel material and the heating element cooperate such that relative humidity within the container decreases from about 100% to between about 55% and about 60% over a time period of about 40 minutes while the closing flap is in a closed position. According to another aspect of the invention, the panel material and the heating element cooperate such that relative humidity within the container decreases from about 100% to about 55% over a time period of about 40 minutes while the closing flap is in a closed position.
The panel material preferably includes an interior fabric, an exterior fabric, and an insulating fabric disposed between the interior and exterior fabrics. The interior and exterior fabrics comprise nylon and the insulating fabric comprises polyester.
The container preferably comprises a second pocket, the second pocket defining a second pocket opening, the first pocket disposed proximate the interior surface of the lower panel, the second pocket disposed proximate the interior surface of the upper panel. First and second modular heating elements are disposed in said respective first and second pockets. The first and second modular elements are vapor-permeable. The first pocket opens toward the rear panel. A fastener portion is disposed in the first pocket and fixed to the interior surface of said at least one panel. The fastener portion preferably is a hook portion of a hook-and-loop fastener or a loop portion of a hook-and-loop fastener.
According to another aspect of the invention, a method of maintaining a pizza at a desired temperature and moisture content during delivery comprises providing a portable container, the container including an upper panel, a lower panel, a rear panel, first and second side panels, a closing flap, a pocket and a modular heater, said rear and first and second side panels extending between the upper panel and the lower panel, the flap extending from the lower panel, the upper, lower, rear, first and second side panels and flap including a substantially flexible insulating panel material including interior and exterior surfaces, the panel material capable of allowing moisture to pass from an interior of the container to an exterior of the container, the pocket defining a pocket opening and disposed proximate the interior surface of one of the upper, lower, rear, and side panels, the modular heater disposed in the pocket, placing the pizza in the container, closing the flap, providing electricity to the modular heater, and maintaining a desired temperature and moisture content within the portable container.
A pair of pizzas are placed in the container, according to one embodiment. The method preferably further comprises decreasing relative humidity within the container to between about 40% and about 60% over a time period of about 40 minutes while the flap is closed. According to another aspect, the method further comprises decreasing relative humidity within the container to about 55% over a time period of about 40 minutes while the flap is closed.
It is an object of this invention to provide a portable food container for maintaining prepared food products such as pizza at a desired temperature by using an easily and inexpensively replaceable modular heater. It is another object of this invention to provide a portable food container for maintaining prepared food products such as pizza at a desired temperature by using a modular heater so that the container need not be discarded when the heater needs to be replaced.
It is another object of this invention to provide a portable food container that is made of materials allowing excess moisture from the food products to pass through the material from the container interior to the container exterior. It is another object of this invention to maintain desired moisture content of prepared food products by decreasing the relative humidity within the container.
It is yet another advantage of this invention to provide a portable container constructed primarily with breathable or gas- and/or vapor-permeable materials, to allow substantial vapor/humidity to escape from the interior thereof without undesirable heat loss. Additional objects, advantages, and features of various embodiments of the invention will become apparent to those skilled in the art from the description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are illustrated in the accompanying figures, in which like reference numerals denote like elements and in which:
FIG. 1 is a front perspective view showing a pizza delivery bag according to an embodiment of the invention;
FIG. 1 a is a fragmentary cross-sectional view of a portion of the FIG. 1 delivery bag;
FIG. 2 is a side perspective view of the FIG. 1 delivery bag;
FIG. 3 is a top view of the FIG. 1 bag;
FIG. 4 is a partial side view of the FIG. 1 bag;
FIG. 5 is a bottom view of the FIG. 1 bag;
FIG. 6 is a table showing temperature and humidity characteristics for a variety of insulation materials;
FIG. 7 is a chart showing lab-test characteristics for a bag according to an embodiment of the invention;
FIG. 8 is a chart showing lab-test characteristics for a prior art bag;
FIG. 9 is a graph of temperature loss vs. time for a typical bag;
FIG. 10 is a table showing temperature and humidity characteristics for a typical bag; and
FIGS. 11-14 are graphs and tables showing temperature and humidity characteristics according to embodiments of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
One embodiment of a pizza delivery bag according to the invention is depicted in FIGS. 1-5, generally at 100 . Delivery bag 100 includes upper panel 104 , lower panel 106 , rear panel 108 , respective first and second side panels 110 and 112 , and an openable section, i.e. a closure flap, 114 . Each panel 104 - 112 and closure flap 114 have an interior surface 118 and an exterior surface 120 . Delivery bag 100 thus generally defines an enclosure into which food can be placed through the openable section, e.g. at a pizza restaurant or other baking facility, transported to a remote location, such as a customer's place of residence, and then removed from the enclosure. Although this application may emphasize pizza products and pizza delivery environments, it should be noted that embodiments of the invention are equally applicable to food items other than pizza, non-food items, and/or environments other than delivery environments.
Delivery bag 100 also includes upper and lower pockets 142 , 144 , shown in dotted line representation in FIG. 1 . Upper and lower pockets 142 , 144 are formed from material affixed to interior surfaces of upper and lower panels 104 , 106 , according to the illustrated embodiment. Upper and lower pockets 142 , 144 form respective openings 146 , 148 through which one or more objects can be placed into the pockets, as will be described later in this application. Of course, one or more pockets may be present in only one of upper and lower panels 104 , 106 , and/or in one or more of rear panel 108 , first side panel 110 , and second side panel 112 . Additionally, or alternatively, the one or more pockets can be placed adjacent an exterior surface of bag 100 instead of the interior surface.
Pockets 142 , 144 in this embodiment extend substantially the full width of the upper and lower panels 104 and 106 and a substantial portion of their length, e.g. about 6 inches. Pockets 142 , 144 also open toward rear panel 108 , according to this embodiment. According to this construction, the heating elements are less likely to fall out of the bag. Further, when sliding a pizza box or other food container or food item into the bag, the box is far less likely to “catch” on the pocket or on the heating element itself, reducing the likelihood of bunching the pocket or the heating element e.g. in an “accordion-like” manner, or catching a heating element and driving it towards the rear of the bag. Referring to FIG. 1 a , exemplary panels 104 - 112 and closure flap 114 are formed from material 154 . Material 154 includes interior fabric layer 156 , exterior fabric layer 158 , and insulating fabric layer 160 . These layers preferably are moisture-permeable, yet cooperate and insulate to retain heat within the interior of delivery bag 100 in a manner to be described further.
Inner fabric layer 156 , according to one embodiment, can be a moisture-permeable material, such as 210 denier nylon with a ¾ ounce polyurethane-backed DMR finish. Exterior fabric layer 158 can be a moisture-permeable, 420 denier nylon, also with a ¾ ounce polyurethane-backed DMR finish. In one embodiment, insulation layer 160 is characterized as 12.33 ounces per square yard polyester fiber fill. The material forming upper and lower pockets 142 , 144 is a moisture-permeable nylon, such as the fabric used in exterior fabric layer 158 . However, in other embodiments, the material used for interior fabric layer 156 may be used as well. Alternatively, all three layers of the material 154 can be used to form upper and lower pockets 142 , 144 .
Returning to FIG. 1, bag 100 also includes respective upper and lower fastening portions 164 , 166 , each being e.g. one-half of a typical hook-and-loop fastening mechanism such as that sold under the trademark VELCRO. Of course, other types of fastening mechanisms are contemplated as well. Fastening portions 164 , 166 are disposed on interior surfaces 118 of upper panel 104 and lower panel 106 . Portions 164 , 166 also can be entirely or partially within upper and lower pockets 142 , 144 , if desired. As will be described, portions 164 , 166 are constructed and arranged to mate with corresponding fastening portions disposed on the heating elements or other objects to be inserted into pockets 142 , 144 .
FIG. 1 depicts modular heating elements 168 , one in each of upper and lower pockets 142 , 144 . In this embodiment, loop portion 169 is attached to each modular heating element 168 . Loop portion 169 cooperates with e.g. respective upper and lower hook portions 164 , 166 , previously described, to releasably secure modular heating elements 168 in place within pockets 142 , 144 . Heating elements can extend all the way to the rear of bag 100 , if desired, or only partially to the rear.
Allowing heating elements 168 to be removed and replaced easily provides a number of advantages believed heretofore unknown. Many prior art bags, for example, must not be submerged in a cleaning solution or other liquid because damage to the heating elements likely would result. At the very least, extreme care must be taken to avoid exposing the heating elements to liquid. Folding, storing, packaging and/or otherwise manipulating or handling prior-art bags also can cause damage to the heating elements. Additionally, failure of a single heating element in the prior art compromises the entire bag, requiring expensive repair or, more practically, replacement of the entire bag. These and other disadvantages are believed to have caused unnecessary expense, delay, and other problems.
Modular heating elements suitable for use according to embodiments of the invention are available from a number of different manufacturers. Such heating elements can take the form of electrical resistance wires, for example, embedded or otherwise disposed in a substantially rectangular substrate of relatively stiff material, for example. Heating elements according to the invention also can include solid-sheet polymer technologies, e.g., such as carbon-containing MYLAR®-based integrated-circuit-type heater technologies, resistive-wire technologies, copper bus-bar technologies, and the like. Heating elements in the manner of those described in one or more of the above-identified U.S. patents also can be used. To maintain vapor-releasing characteristics of bag 100 , heating elements according to the invention preferably are themselves at least partially moisture-permeable. Thus, undesirable moisture can escape not only through the sides of the bag but also through the roof and floor thereof, according to the illustrated embodiments. The heating elements can have holes and/or perforations therethrough, or can otherwise be moisture-permeable. For example, moisture can pass between the wires or other individual components making up a specific heating element.
Referring to FIG. 2, closure flap 114 according to this embodiment includes side portion 170 and tapered upper portion 172 . Complimentary fastening portions 174 , 176 are disposed, respectively, on an interior surface of upper portion 172 of flap 114 and on an exterior surface of upper panel 104 . Fastening portions 174 , 176 can comprise hook-and-loop fastening devices such as VELCRO, or other fastening mechanisms or devices.
Tapered upper portion 172 of closure flap 114 preferably comprises generally transparent window 178 . Window 178 can be formed by stitching clear material 180 and binding 182 to material 154 of upper flap portion 172 , e.g. along sides 184 , 186 and bottom 188 . Window 178 preferably opens along top edge 190 thereof, where clear material 180 and binding 182 are stitched together, but not to the underlying material of upper flap portion 172 .
Window 178 preferably is a clear, flexible, transparent polyvinyl chloride film containing compatible, non-migrating plasticizers, such as polymeric adipate plasticizers, in addition to FDA-approved for food contact UV, thermal and oxidative stabilizer additives. Window 178 also can be made from 0.018 inch polypropylene, for example, or other suitable materials known to those skilled in the art.
Referring to FIGS. 1-2, lower panel 106 extends farther forward than upper panel 104 , thereby forming an angled edge on first and second panels 110 , 112 . Further, material extending between closure flap 114 and side panels 110 , 112 forms an overlapping and folding taper side seal when closure flap 114 is in its closed position, for better retaining heat within delivery bag 100 . Binding 182 , in addition to being disposed around the outside of flap 114 , also can be used to join and/or border other portions of bag 100 . Note, for example, FIG. 3 .
As shown in e.g. FIG. 2, webbing 192 is stitched to first and second side panels 110 , 112 . Webbing 192 preferably extends from stitching joining side panels 110 , 112 with lower panel 106 . Webbing 192 extends from side panels 110 , 112 to form straps 194 , 196 , 198 , and 200 . These straps preferably are stitched or otherwise connected at a central area above bag 100 to form handle 202 . Webbing 192 , straps 194 - 200 and handle 202 ideally are disposed and formed such that delivery bag 100 will be balanced when handle 202 is grasped. According to one embodiment, webbing 192 is 1½ inches wide.
Referring to FIGS. 4 and 5, bottom handle 210 is affixed to the exterior surface of lower panel 106 by stitching, for example. Bottom handle 210 can be made from webbing e.g. 3 inches in width, and has a length of about 7 inches in one embodiment. Handle 210 is generally centrally affixed to the exterior surface of lower panel 106 , so that delivery bag 100 is generally balanced when lower handle 210 is used. Using lower handle 210 reduces the likelihood that pizzas, pizza slices or other food product will “rock” or otherwise undesirably move while the bag is being transported. Grabbing bag 100 solely by upper handle 202 may cause bag 100 to swing, e.g. while walking, causing the food product to shift. Either handle 202 , 210 may be used separately or in combination when the delivery bag 100 is being carried. Lower panel 106 , or any other desired portion of bag 100 , also can include identifying indicia, care instructions or other information 212 .
Power can be supplied to one or more heating elements 168 by e.g. electrical lead 223 , shown in FIG. 1 . Lead 223 preferably passes through an opening (not shown) in rear panel 108 and can terminate in quick release connector 224 . Quick release connector 224 couples to a connector 225 on power cord 226 . Plug 227 is present on the other end of power cord 226 and fits into an automobile's cigarette lighter, according to this embodiment.
Also as shown in FIG. 1, generally at 228 , a bottom seam of floor pocket 144 can be open and angled, exposing heating element 168 and allowing a user of bag 100 to verify presence and proper disposition of heating element 168 within pocket 144 .
Graphical and other data in connection with embodiments of the invention now will be described with respect to FIGS. 6-14.
The data presented in FIG. 6 show temperature and humidity characteristics for vinyl bags of the prior art vs. bags according to embodiments of the invention, each of the latter incorporating a different insulating material. Specifically, FIG. 6 shows interior temperature changes at 20 and 40 minutes after insertion of a representative food product and closure of the flap, and an overall humidity rating. As shown, polyester 12.33-ounce is a desirable insulating material. Polyester 9-ounce is a potentially acceptable second choice, assuming the noted four degree temperature difference at 20 minutes is not disqualifying. At the opposite end of the spectrum, vinyl and THINSULATE brand insulation generally would be considered unsatisfactory due to unacceptable moisture retention.
FIG. 7 depicts laboratory test results showing temperature readings for two pizzas stacked in a bag according to an embodiment of the invention. FIG. 8 shows temperature readings for a delivery bag of the prior art. More specifically, the results in FIG. 7 were taken using a bag having inner and outer fabric layers of breathable nylon with a polyester fiberfill insulation, as described above. Modular heating elements generally as described herein were present in the upper and lower pockets. The modular heater used a 12 Volt electric source to attain a final temperature of 185° F. after a 10 minute warm-up period. The two modular heating assemblies together weighed about 1 pound and the delivery bag weighed about 1.1 pound, for a total weight of about 2.1 pounds. The data in FIG. 8 were taken from readings in a delivery bag made from a cordura nylon with a THINSULATE layer. A heating element of the stored-heat-disc type used 110 Volt AC power to attain a final temperature of 160° F. after 60 minutes. As can be seen, the top pizza in the FIG. 7 cooled only 10° after 40 minutes, while the bottom pizza cooled 19°. The temperatures of the respective pizzas then maintained. With the FIG. 8 device, on the other hand, the top pizza cooled 21° and the bottom pizza cooled 18° in the same time frame, and continued to cool afterwards.
FIGS. 9 and 10 depict temperatures of top and bottom pizzas and relative humidities taken in a prior-art vinyl bag without a heater. FIGS. 11 and 12 show the same data for a delivery bag according to an embodiment of the invention with at least one heating element, relative humidity being measured using a hydrometer in the heated bag. As can be seen by comparing FIGS. 9 and 10 with FIGS. 11 and 12, the bag according to the invention better retained heat within the tested time interval. Moreover, the bag according to the invention facilitated an advantageous decline in relative humidity, while the prior art bag retained virtually all humidity. This decline is believed due, at least in part, to the breathable structures used according to the invention, and/or the thermal output of the at least one heating element, and/or direct moisture escape due to the non-sealed nature of the bag. Excess humidity, of course, can cause a number of disadvantages, such as damp or wet pizza boxes or other food containers, soggy pizza crust or other food product, moisture-saturated delivery bag material, mildew, odor, etc.
FIG. 13 shows delivery bag heat loss for different bag-heater combinations, the bag enclosing at least one pizza. The pizza used in this instance was a PAN SUPREME brand pizza available from Pizza Hut, Inc. Curve 230 (white-diamond) depicts a bag according to an embodiment of this invention with a first type of modular heating element. Curve 232 (black-diamond) represents a bag according to an embodiment of the invention with a second type of modular heating element. Curve 234 (white-square) represents a bag according to an embodiment of the invention with a third type of modular heating element. Curve 236 (black-square) represents a bag with a fourth type of heating element. Curve 238 (white-triangle) represents a prior-art vinyl bag without a heating element. Curve 240 (crosshatched-square) represents an empty bag. As can be seen, the temperature loss was minimized when the first three modular heating elements were used. Therefore, a number of different heating elements may be suitable within the context of this invention.
FIG. 14 shows humidity levels for types of heaters used in a bag according to an embodiment of the invention, the bag enclosing at least one pizza. A PAN SUPREME brand pizza available from Pizza Hut, Inc. was used in this instance. Curve 242 (white-square) represents a vinyl, prior-art bag and/or a bag with a prior-art heating element. Curve 244 (black-diamond) represents a bag according to an embodiment of this invention with a second type of modular heating element. Curve 246 (white-triangle) represents a bag according to an embodiment of this invention with a third type of modular heating element. While differences between types of modular heaters where shown, FIG. 14 clearly depicts the advantageous decrease in relative humidity over time when a bag according to the invention is used.
According to embodiments of the invention, relative humidity within delivery bag 100 decreases, tending to prevent undesirable sogginess in the crust of a pizza contained in the bag. Additionally, the materials of the bag itself do not emit toxic or undesirable substances and do not absorb (or adsorb) excess water. Thus, mold, mildew, and other adverse effects are generally reduced, if not avoided entirely. Additionally, the present delivery bag can be easily and effectively cleaned.
Relative humidities in the interior of a delivery bag according to an embodiment of the invention drop to a more desirable level, for example to a range between about 40% and 60%, and/or to a range between about 55% and 70%, more specifically, to a range between about 55% and 60%, and yet more specifically, to about 55%, over the time periods depicted in e.g. FIG. 14 . Additionally, also unlike many prior art bags, temperature characteristics are maintained at a desirable level over an extended period of time. For example, temperature loss is maintained within a range of between about 0-10° F. over a time of up to about 40 minutes. More specifically, temperature loss may be maintained within a range of about 3-6° F. at a time-from-start period of between about 10-30 minutes (see FIG. 13 ). Maintaining heat, while releasing excess humidity, provides significant advantages over the bags of the prior art.
Because numerous modifications of this invention may be made without departing from the spirit thereof, the scope of the invention is not to be limited to the embodiments illustrated and described. For example, although one embodiment of the disclosed bag can have interior dimensions of about 18 inches by 18 inches by 6 inches, any suitable dimensions are contemplated. A variety of color schemes are contemplated, e.g. red for exterior surfaces and black for interior surfaces. Embodiments of the invention are not necessarily limited to transporting pizza products or even food products. Other modifications and variations will be apparent to those of ordinary skill. | A delivery bag for pizza or other products includes upper, lower, rear, and first and second side panels and a closure flap. The panels and flap are made from a substantially flexible insulating panel material and have interior and exterior surfaces. The panel material is capable of conveying moisture from the interior surface to the exterior surface. The delivery bag also includes one or more pockets fixed to interior surfaces of the panels. A modular heating element is disposed in each pocket. The delivery bag as described advantageously maintains temperatures of pizzas therein, yet allows relative humidity to decline over a specified period of time, thereby preventing e.g. pizza crusts from becoming soggy. Corresponding methods provide similar advantages. | 1 |
This disclosure is a division of patent application Ser. No. 08/738,935, filed on Oct. 24, 1996, now U.S. Pat. No. 6,005,289.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for manufacturing a semiconductor device comprising a printed circuit board type ball grid array (hereinafter referred to as a BGA) and a package for the semiconductor device and, more particularly, to a method for manufacturing a semiconductor device comprising a printed circuit board type BGA package in which a plurality of printed wiring boards are laminated, and a package for the semiconductor device.
2. Description of the Background Art
FIG. 57 is a sectional view showing the structure of a semiconductor device according to the prior art. In FIG. 57, the reference numeral 1 designates a semiconductor device comprising a printed circuit board type BGA package, the reference numeral 2 designates a chip provided in the semiconductor device 1 , the reference numeral 3 designates a slug on which the chip 2 is placed, the reference numeral 4 designates a die bonding resin which bonds the chip 2 to the slug 3 , the reference numeral 5 designates a frame that is provided around the chip 2 and has one of main surfaces to which the slug 3 is bonded, the reference numeral 6 designates an adhesive bonding the frame 5 to the slug 3 , the reference numeral 7 designates a solder ball formed on the other main surface of the frame 5 , the reference numeral 8 designates a wire electrically connecting the chip 2 to the frame 5 , the reference numeral 9 designates a cavity formed in the central portion of the frame 5 to housing the chip 2 therein, the reference numeral 10 designates a sealing resin for filling in the cavity 9 to seal the chip 2 , and the reference numeral 11 designates a dam which is formed on the other main surface of the frame 5 enclosing an opening and preventing the sealing resin 10 from flowing out.
The frame 5 comprises two double-sided printed circuit boards 15 and 16 which are laminated, and a prepreg 17 for bonding them. The double-sided printed circuit board 15 has wiring layers 19 and 20 provided on both sides of an insulating substrate 18 . The double-sided printed circuit board 16 has wiring layers 22 and 23 provided on both sides of an insulating substrate 21 .
The wiring layers 19 and 20 and the wiring layers 22 and 23 provided on both sides of the double-sided printed circuit boards 15 and 16 are wired by interstitial via holes, respectively. The double-sided printed circuit boards 15 and 16 are wired by a through hole 24 .
The exchange of a signal and power between the chip 2 and a board on which the semiconductor device 1 is placed occurs through the wire 8 , the wiring layers 19 , 20 , 22 and 23 , the through hole 24 , an interstitial via hole 25 , the solder ball 7 and the like.
A method for manufacturing the printed circuit board type BGA package according to the prior art shown in FIG. 57 will be described below with reference to FIGS. 43 to 57 .
First of all, a double-sided printed circuit board 15 having copper foils 30 and 31 laminated on both sides is prepared (see FIG. 43 ).
Then, a hole 32 for an interstitial via hole which penetrates the double-sided printed circuit board 15 is formed (see FIG. 44 ). The double-sided printed circuit board 15 on which the hole 32 is formed is plated with copper so that a copper plated layer 33 is formed. Thus, an interstitial via hole 25 is formed (see FIG. 45 ). As shown in FIG. 46, the interstitial via hole 25 is filled with a resin 34 . Consequently, no gap which penetrates the double-sided printed circuit board 15 is present. Then, a wiring layer 20 of the double-sided printed circuit board 15 is patterned (see FIG. 47 ).
After performing the same steps as the steps shown in FIGS. 43 to 47 , a double-sided printed circuit board 16 is prepared in which the interstitial via hole 25 that is filled with the resin 34 is formed and a wiring layer 22 is patterned (see FIG. 48 ). The double-sided printed circuit board 16 comprises copper foils 35 and 36 , and a copper plated layer 37 formed thereon.
Then, the double-sided printed circuit board 15 shown in FIG. 47 and the double-sided printed circuit board 16 shown in FIG. 48 are bonded together by prepreg 17 . Consequently, a laminated printed circuit board 38 is formed as an aggregate of the double-sided printed circuit boards 15 and 16 (see FIG. 49 ). A chamber 39 for forming a cavity 9 shown in FIG. 57 is provided between the double-sided printed circuit boards 15 and 16 in the central portion of the laminated printed circuit board 38 . A hole 40 which penetrates the laminated printed circuit board 38 is formed in a region 41 of the laminated printed circuit board 38 where the prepreg 17 is inserted (see FIG. 50 ). The laminated printed circuit board 38 in which the hole 40 is formed is plated with copper so that a copper plated layer 42 is formed. Thus, a through hole 24 is formed (see FIG. 51 ). The laminated printed circuit board 38 is immersed in a plating solution so as to be plated with copper. However, the interstitial via hole 25 has been filled with a resin so that the chamber 39 has been sealed. For this reason, the plating solution does not invade the chamber 39 .
Subsequently, the through hole 24 is filled with a resin 43 as shown in FIG. 52 . Then, a wiring layer 19 is patterned (see FIG. 53 ). At the same time, the copper foil 30 and the copper plated layers 33 and 42 of the wiring layer 19 which are provided in an upper region 44 of the chamber 39 are removed. An insulating substrate 18 provided in the upper region 44 is opened by a router so that an opening 45 is formed. After that, nickel-gold plating is performed so that a nickel-gold plated layer 46 is formed on the copper plated layers 37 and 42 (see FIG. 54 ).
As shown in FIG. 55, a wiring layer 23 is patterned. At the same time, the copper foil 35 and the copper plated layers 37 and 42 which are provided in a lower region 47 of the chamber 39 are removed. As shown in FIG. 56, an opening 48 is formed in the lower region 47 so that a frame 5 is completed. A slug 3 is bonded to the frame 5 with an adhesive 6 .
The chip 2 is bonded to the slug 3 with a die bonding resin 4 and the chip 2 is connected to the nickel-gold plated layer 46 by a wire 8 . After a dam 11 is put in place, the cavity 9 is filled with a sealing resin 10 so that a package is sealed. Then, a solder ball 7 is formed on the nickel-gold plated layer 46 of the wiring layer 19 . Thus, the printed circuit board type BGA package is completed (see FIG. 57 ).
The semiconductor device and the method for manufacturing the semiconductor device according to the prior art have the above-mentioned structure. Therefore, the copper plated layers 33 and 37 are formed on the copper foils 31 and 36 of the wiring layers 20 and 22 , and the copper plated layer 33 or 37 and the copper plated layer 42 are formed doubly on the copper foils 30 and 37 of the wiring layers 19 and 23 . Consequently, the thicknesses of the wiring layers 19 , 20 , 22 and 23 become greater. For this reason, it is hard to reduce the pitches of patterns formed on the wiring layers 19 , 20 , 22 and 23 .
The above-mentioned problem will be described below with reference to FIGS. 58 and 59. FIG. 58 is a sectional view showing the state in which a wiring layer 50 A is formed by a copper foil 52 and a copper plated layer 51 and a pattern is formed at a minimum pitch. The formed pattern has a predetermined inclination 53 which depends on the conditions of patterning. In FIG. 58, the reference numeral 55 designates a space between patterns which is required at the minimum, and the reference numeral 54 designates a pattern pitch. FIG. 59 is a sectional view showing the state in which a wiring layer 50 B is formed by only the copper foil 52 and a pattern is formed at a minimum pitch. Similarly to the section of the pattern shown in FIG. 58, the pattern shown in FIG. 59 has a predetermined inclination 53 which depends on the conditions of patterning. In FIG. 59, the reference numeral 55 designates a space between patterns which is required at the minimum, and the reference numeral 56 designates a pattern pitch. As seen from a comparison between FIGS. 58 and 59, the pitch 54 is greater than the pitch 56 . When the thickness of the wiring layer is increased, it becomes harder to reduce the pitch of the wiring pattern.
Furthermore, the through hole 24 and the interstitial via hole 5 should be plated separately at the plating step. Consequently, the number of manufacturing steps is increased.
In addition, it is necessary to immerse the laminated printed circuit board 38 in the plating solution when forming the through hole 24 at the manufacturing steps. For this reason, a step of filling the interstitial via hole 25 with the resin cannot be omitted.
SUMMARY OF THE INVENTION
A first aspect of the present invention is directed to a method for manufacturing a semiconductor device, comprising the steps of preparing a first printed circuit board having an insulating substrate, a first metallic foil formed on a first main surface of the insulating substrate, a second metallic foil formed on a second main surface of the insulating substrate, and a first hole formed thereon, the first hole penetrating the first metallic foil to reach the second metallic foil and being covered with the second metallic foil, patterning the second metallic foil with a region covering the first hole left, bonding a predetermined member to the second main surface of the insulating substrate so as to form a chamber which faces the region covering the first hole and is sealed, plating the first hole to form a first conductive path for connecting the first and second metallic foils, and forming openings which reach the chamber for an aggregate including the first printed circuit board and the predetermined member after the step of forming the first conductive path.
A second aspect of the present invention is directed to the method for manufacturing a semiconductor device according to the first aspect of the present invention, wherein the step of preparing the first printed circuit board comprises the steps of forming the first metallic foil on the first main surface of the insulating substrate, forming the first hole which penetrates the insulating substrate and the first metallic foil, and laminating the second metallic foil on the second main surface of the insulating substrate.
A third aspect of the present invention is directed to the method for manufacturing a semiconductor device according to the first aspect of the present invention, wherein the step of preparing the first printed circuit board comprises the steps of preparing the insulating substrate having the first and second metallic foils provided on the first and second main surfaces thereof respectively, patterning the first metallic foil in a region where the first hole should be formed, and irradiating laser beams from the patterned first metallic foil side.
A fourth aspect of the present invention is directed to the method for manufacturing a semiconductor device according to the first, second or third aspect of the present invention, wherein the predetermined member includes a laminated product having a first main surface bonded to the second main surface of the insulating substrate, a second main surface and a third metallic foil formed on the second main surface, further comprising the step of forming a second hole which penetrates a portion from the third metallic foil to the first metallic foil before the step of forming the first conductive path, and wherein a second conductive path for connecting the third metallic foil to the first metallic foil is simultaneously formed at the step of forming the first conductive path.
A fifth aspect of the present invention is directed to the method for manufacturing a semiconductor device according to the fourth aspect of the present invention, wherein the laminated product includes a second printed circuit board having a first main surface on which the third metallic foil is formed, a second main surface, and a fourth metallic foil which is formed on the second main surface, further comprising the step of forming a third hole which penetrates the third metallic foil to reach the fourth metallic foil and is covered with the fourth metallic foil for the first printed circuit board before the step of forming the first conductive path.
A sixth aspect of the present invention is directed to the method for manufacturing a semiconductor device according to the fourth aspect of the present invention, wherein the laminated product is formed through the steps of preparing an insulating base having the third metallic foil on a first main surface of the insulating base and a concave portion on a second main surface of the insulating bace, and a second printed circuit board having a fourth metallic foil on a first main surface of the second printed circuit board, a fifth metallic foil on a second main surface of the second printed circuit board, and a third hole formed on the second printed circuit board, the third hole penetrating the fourth metallic foil to reach the fifth metallic foil and being covered with the fifth metallic foil, patterning the fifth metallic foil with a region covering the third hole left, bonding the second main surface of the insulating base to the second main surface of the second printed circuit board, and plating the third hole to form a third conductive path for connecting the fourth and fifth metallic foils.
A seventh aspect of the present invention is directed to the method for manufacturing a semiconductor device according to any of the first to sixth aspects of the present invention, wherein the first hole includes a slit-shaped hole.
An eighth aspect of the present invention is directed to the method for manufacturing a semiconductor device according to the seventh aspect of the present invention, wherein the step of forming the opening comprises the steps of scraping off the inner wall of the slit-shaped hole with the outer wall of the slit-shaped hole left so as to expose the bottom section of the slit-shaped hole, scraping off the upper portion of the outer wall of the slit-shaped hole by spot-facing, and forming a pad on the bottom of the slit-shaped hole.
A ninth aspect of the present invention is directed to a package for a semiconductor device having a plurality of double-sided printed circuit boards laminated such that a portion where a cavity for placing a semiconductor chip on the package should be formed is hollow, at least one of the double-sided printed circuit boards comprising an insulating substrate having first and second main surfaces, and a through hole which penetrates a portion from the first main surface to the second main surface, a first metallic foil which is provided on the first main surface of the insulating substrate and has an opening conforming to the through hole, a second metallic foil which is provided on the second main surface of the insulating substrate and has a region that covers the through hole, and a metallic wire which is provided in the through hole and connects the first metallic foil to the second metallic foil.
A tenth aspect of the present invention is directed to the package for a semiconductor device according to the ninth aspect of the present invention, wherein the through hole includes a slit-shaped hole.
An eleventh aspect of the present invention is directed to a package for a semiconductor device having a plurality of laminated double-sided printed circuit boards which enclose a cavity for placing a semiconductor chip, at least one of the double-sided printed circuit boards comprising an insulating substrate having first and second main surfaces, and an opening for forming the cavity, a first wiring layer provided on the first main surface of the insulating substrate, a second wiring layer provided on the second main surface of the insulating substrate, a first pad provided on the first wiring layer, and a second pad provided on the first main surface side of the second wiring layer.
A twelfth aspect of the present invention is directed to a package for a semiconductor device having a plurality of double-sided printed circuit boards laminated such that a portion where a cavity for placing a semiconductor chip should be formed is hollow, at least one of the double-sided printed circuit boards comprising an insulating substrate having first and second main surfaces, and a slit-shaped through hole which penetrates a portion from the first main surface to the second main surface, a first wiring layer which is provided on the first main surface of the insulating substrate and has an opening conforming to the through hole, a second wiring layer which is provided on the second main surface of the insulating substrate and has an opening conforming to the through hole, and a metallic wire which is provided in the through hole and connects the first wiring layer to the second wiring layer.
According to the first aspect of the present invention, the method for manufacturing a semiconductor device comprises the steps of patterning the second metallic foil with a region covering the first hole left, and bonding a predetermined member to the second main surface of the insulating substrate so as to form a chamber which faces the region covering the first hole and is sealed. The second metallic foil is not plated when forming the first conductive path. Only the second metallic foil is patterned. Consequently, a thin conductor layer can be patterned and a pitch between the patterned wirings can be reduced.
According to the second aspect of the present invention, the method for manufacturing a semiconductor device comprises the steps of forming the first metallic foil on the first main surface of the insulating substrate, forming the first hole which penetrates the insulating substrate and the first metallic foil, and laminating the second metallic foil on the second main surface of the insulating substrate. The order of steps according to the prior art can be replaced. Consequently, the first printed circuit board can be prepared easily.
According to the third aspect of the present invention, the method for manufacturing a semiconductor device comprises the steps of preparing the insulating substrate having the first and second metallic foils provided on the first and second main surfaces thereof respectively, patterning the first metallic foil in a region where the first hole should be formed, and irradiating laser beams from the patterned first metallic foil side. The insulating substrate having metallic foils provided on both sides thereof can be used. Consequently, the first printed circuit board can be prepared easily.
According to the fourth aspect of the present invention, the second conductive path for connecting the third metallic foil to the first metallic foil is simultaneously formed at the step of forming the first conductive path. Consequently, the steps of performing plating to form the conductive path and the like can be reduced more as compared with the steps of forming the first and second conductive paths separately. Thus, the manufacturing process can be simplified.
According to the fifth aspect of the present invention, the method for manufacturing a semiconductor device comprises the step of forming a third hole which penetrates the third metallic foil to reach the fourth metallic foil and is covered with the fourth metallic foil for the first printed circuit board before the step of forming the first conductive path. Consequently, the first conductive path can be formed on the first hole. At the same time, a conductive path can be formed on the third hole. Thus, the manufacturing process can be simplified.
According to the sixth aspect of the present invention, the laminated product which is formed by bonding the insulating substrate to the second printed circuit board is used. The chamber is formed between the insulating substrate and the second printed circuit board. Consequently, it is possible to obtain a semiconductor device in which a portion for supporting a cover is provided on the insulating substrate and bonding can be performed by using a fifth metallic foil that is patterned on the second main surface of the second printed circuit board.
According to the seventh aspect of the present invention, the first hole is a slit-shaped hole. Consequently, the resistance value of an interstitial via hole can be reduced.
According to the eighth aspect of the present invention, the pad is formed on the outer wall and bottom of the slit-shaped hole which is exposed at the steps of scraping off the inner wall of the slit-shaped hole with the outer wall thereof left so as to expose the bottom section of the slit-shaped hole, and scraping off the upper portion of the outer wall of the slit-shaped hole to perform spot-facing for exposing the bottom of the slit-shaped hole. Consequently, the pad can be formed at a height corresponding to the first and second main surfaces of the insulating substrate. The semiconductor device can be easily manufactured by varying the height of the pad.
According to the ninth aspect of the present invention, a package for a semiconductor device comprises a second metallic foil which is provided on the second main surface of the insulating substrate and has a region that covers the through hole. Therefore, the first and second main surfaces of the insulating substrate are blocked. For example, the second metallic foil is not exposed to a liquid such as a plating solution or gases when plating the first metallic foil. Thus, it is possible to obtain the package for a semiconductor device which can be manufactured easily.
According to the tenth aspect of the present invention, the metallic wiring is provided on the slit-shaped hole as a through hole. Consequently, the resistance value of the metallic wiring can be reduced.
According to the eleventh aspect of the present invention, the first and second pads are provided on the first main surface side. However, the heights of the first and second pads are different from each other by the thickness of the insulating substrate. Consequently, it is possible to lessen a possibility that the bonded wires might be short-circuited.
According to the twelfth aspect of the present invention, the metallic wiring which is provided in the through hole and connects the first and second wiring layers is slit-shaped. Consequently, the connection resistance of the first and second wiring layers can be reduced.
In order to solve the above-mentioned problems, it is an object of the present invention to reduce the number of manufacturing steps by plating a through hole and an interstitial via hole at the same time.
It is another object of the present invention to perform patterning easily at a small pitch without a plated layer formed on a copper foil when plating is carried out to form the interstitial via hole.
It is yet another object of the present invention to provide a method for manufacturing a semiconductor device having a printed circuit board type BGA package in which a step of filling the interstitial via hole with a resin can be omitted.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a step in manufacturing a semiconductor device according to a first embodiment of the present invention;
FIG. 2 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 3 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 4 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 5 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 6 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 7 is a sectional view showing, a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 8 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 9 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 10 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 11 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 12 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 13 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 14 is a sectional view showing a step in manufacturing the semiconductor device according to the first embodiment of the present invention;
FIG. 15 is a perspective view showing the structure of a semiconductor device according to the first embodiment of the present invention;
FIG. 16 is a plan view showing the structure of the semiconductor device according to the first embodiment of the present invention;
FIG. 17 is a plan view showing the structure of the semiconductor device according to the first embodiment of the present invention;
FIG. 18 is a sectional view showing a step in manufacturing a semiconductor device according to a second embodiment of the present invention;
FIG. 19 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 20 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 21 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 22 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 23 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 24 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 25 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 26 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 27 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 28 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 29 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 30 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 31 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 32 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 33 is a sectional view showing a step in manufacturing the semiconductor device according to the second embodiment of the present invention;
FIG. 34 is a plan view for explaining a semiconductor device according to a third embodiment of the present invention;
FIG. 35 is a plan view for explaining the semiconductor device according to the third embodiment of the present invention;
FIG. 36 is a plan view showing the structure of the semiconductor device according to the third embodiment of the present invention;
FIG. 37 is a sectional view showing a step in manufacturing a semiconductor device according to a fourth embodiment of the present invention;
FIG. 38 is a sectional view showing a step in manufacturing the semiconductor device according to the fourth embodiment of the present invention;
FIG. 39 is a sectional view showing a step in manufacturing the semiconductor device according to the fourth embodiment of the present invention;
FIG. 40 is a sectional view showing a step in manufacturing a semiconductor device according to a fifth embodiment of the present invention;
FIG. 41 is a sectional view showing a step in manufacturing the semiconductor device according to the fifth embodiment of the present invention;
FIG. 42 is a sectional view showing a step in manufacturing the semiconductor device according to the fifth embodiment of the present invention;
FIG. 43 is a sectional view showing a step in manufacturing a semiconductor device according to the prior art;
FIG. 44 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 45 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 46 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 47 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 48 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 49 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 50 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 51 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 52 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 53 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 54 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 55 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 56 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 57 is a sectional view showing a step in manufacturing the semiconductor device according to the prior art;
FIG. 58 is a sectional view for explaining the relationship of the thickness of a wiring with a space between the wirings; and
FIG. 59 is a sectional view for explaining the relationship of the thickness of the wiring with the space between the wirings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
A method for manufacturing a semiconductor device according to a first embodiment of the present invention will be described below. FIGS. 1 to 14 are sectional views showing step in manufacturing the semiconductor device. After sequentially performing the steps shown in FIGS. 1 to 14 , the semiconductor device according to the first embodiment is completed.
As shown in FIG. 1, a printed circuit board 15 b is prepared in which a copper foil 30 is formed on one of main surfaces of an insulating substrate 18 . The printed circuit board 15 b is a kind of laminated product comprising the copper foil and the insulating substrate. As shown in FIG. 2, a hole 60 for an interstitial via hole is formed. The hole 60 penetrates the printed circuit board 15 b.
Then, a copper foil 31 a is laminated on the other main surface of the insulating substrate 18 so that a double—sided printed circuit board 15 a is formed (see FIG. 3 ). As shown in FIG. 4, the copper foil 31 a of a wiring layer 20 a is patterned. At this time, the copper foil 31 a in a region 61 which covers the hole 60 is not etched but left. In this case, the patterned wiring layer 20 a is formed by only the copper foil 31 a . Consequently, the pitch of a wiring pattern can be reduced more than the pattern of the wiring layer 20 shown in FIG. 47 .
After performing the same steps as the steps shown in FIGS. 1 to 4 , a double-sided printed circuit board 16 a is prepared in which a hole 62 for an interstitial via hole is formed and a wiring layer 29 a is patterned (see FIG. 5 ). A copper foil 36 a in a region 63 where the hole 62 for the interstitial via hole is formed is left. The patterned wiring layer 22 a is formed by only the copper foil 36 a . Consequently, the pitch of a wiring pattern can be reduced more than in the patterned wiring layer 22 shown in FIG. 48 .
The double-sided printed circuit board 15 a shown in FIG. 4 is bonded to a double-sided printed circuit board 16 a shown in FIG. 5 by a prepreg 17 . Consequently, a laminated printed circuit board 38 a is formed as an aggregate of the double-sided printed circuit boards 15 a and 16 a (see FIG. 6 ). The prepreg 17 is not present in some regions so that a chamber 39 for forming a cavity is provided between the double-sided printed circuit boards 15 a and 16 a in the central portion of the laminated printed circuit board 38 a . A hole 65 is formed in a region 64 of the laminated printed circuit board 38 a where the prepreg 17 is inserted. The hole 65 penetrates the laminated printed circuit board 38 a (see FIG. 7 ). The laminated printed circuit board 38 a on which the hole 65 is formed is plated with copper so that a copper plated layer 66 is formed. Thus, a through hole 24 and an interstitial via hole 25 a are formed (see FIG. 8 ). In that case, it is apparent that the metal surfaces of the copper foils 31 a and 36 a are exposed and contact the copper plated layer 66 after the cleaning technique according to the prior art. The laminated printed circuit board 38 a is immersed in a plating solution so as to be plated with copper. As shown in FIG. 7, however, the holes 60 and 62 for the interstitial via holes are closed by the copper foils 31 a and 36 a so that the chamber 39 is sealed. Consequently, the plating solution does not invade the chamber 39 .
As shown in FIG. 9, the through hole 24 and the interstitial via hole 25 a are filled with a resin 67 . A wiring layer 19 a is patterned (see FIG. 10 ). In that case, the copper foil 30 and the copper plated layer 66 provided in an upper region 44 of the chamber 39 are also removed. At this time, the thickness of the patterned wiring layer 19 a is smaller, by the thickness of a copper plated layer 42 , than that the wiring layer 19 according to the prior art which is being patterned as shown in FIG. 53 . Consequently, it is easy in the invention to form a finer pattern.
The insulating substrate 18 provided in the upper region 44 is opened by a router so that an opening 45 is formed. After that, nickel-gold plating is performed so that a nickel-gold plated layer 69 is formed on the copper plated layers 36 a and 66 (see FIG. 11 ).
Then, a wiring layer 23 a is patterned as shown in FIG. 12 . In that case, a copper foil 35 and the copper plated layer 66 which are provided in a region 47 below the chamber 39 are removed. The patterned wiring layer 23 a is formed by the copper foil 35 and the copper plated layer 66 , and has a thickness which is smaller, by the thickness of a copper plated layer 42 , than that of the wiring layer 23 according to the prior art which is being patterned as shown in FIG. 55 . Consequently, it is easy to make the pattern of the wiring layer 23 a finer.
As shown in FIG. 13, an opening 48 is formed in the region 47 so that a frame 5 a is completed. A slug 3 is bonded to the frame 5 a with an adhesive 6 .
As shown in FIG. 14, a chip 2 is bonded to the slug 3 with a die bonding resin 4 and is connected to a nickel-gold plated layer 69 by a wire 8 . After a dam 11 is attached, a cavity 9 is filled with a sealing resin 10 . Consequently the package is sealed. Then, a solder ball 7 is formed on the nickel-gold plated layer of the wiring layer 19 a . Thus, a semiconductor device 1 a having a printed circuit board type BGA package is completed.
FIG. 15 is a perspective view showing the structure of the printed circuit board type BGA package shown in FIG. 14 . In FIG. 15, the resin 10 shown in FIG. 14 is omitted or the state in which the resin 10 has not been injected is shown. In FIG. 15, the same reference numerals designate the same portions as in FIG. 14 . FIG. 16 is an enlarged plan view showing the central portion of the printed circuit board type BGA package shown in FIG. 15 . In FIG. 16, the reference numerals 70 a and 70 b designate power source—ground rings which are provided on an upper stage 73 and supply a source voltage and a ground voltage, the reference numeral 71 designates a wire bonding pad which protrudes from the power source—ground rings 70 a and 70 b in order to arrange stitch bonding positions, the reference numeral 72 a designates a wire bonding pad which is provided on a lower stage 74 of the frame 5 a , the reference numeral 72 b designates a wire bonding pad provided on the upper stage 73 of the frame Da, the reference numeral 75 designates a power source ground—plane which is provided on the lower stage 74 and supplies a source voltage or a ground voltage, the reference numeral 76 designates a wire bonding pad which protrudes from the power source—ground plane 75 in order to arrange the stitch bonding positions, and the same reference numerals designate the same portions as in FIG. 14 . FIG. 17 is a plan view showing another example of the printed circuit board type BGA package shown in FIG. 15, in which the stitch bonding positions are different from those in FIG. 16 . The printed circuit board type BGA package shown in FIG. 17 is characterized in that the wire bonding pads 71 and 76 are not provided but the wire bonding position is placed on the ring. It is apparent that the invention described in the first embodiment can also be applied to the printed circuit board type BGA packages having the structures shown in FIGS. 16 and 17.
In a method for manufacturing a semiconductor device according to the first embodiment, a thin layer formed by the copper foil 30 and copper plated layer 66 or the copper foil 3 ) and copper plated layer 66 of the wiring layers 19 a and 23 a is patterned in the steps shown in FIGS. 10 and 12. Consequently, it is easy to make the pattern finer. Also in the case where the wiring layers 20 a and 22 a are etched as shown in FIGS. 4 and 5, the copper plated layer is not formed on the copper foils 31 a and 36 a . Therefore, it is possible to perform finer patterning than in the prior art.
The manufacturing steps shown in FIGS. 1 to 14 are compared with the manufacturing steps shown in FIGS. 43 to 57 . At the steps according to the prior art, the through hole 24 and the interstitial via hole 25 are formed and filled with a resin separately. On the contrary, the through hole 24 and the interstitial via hole 25 a are simultaneously formed and filled with the resin at the steps shown in FIGS. 1 to 14 . Consequently, the process can be simplified.
As compared with the semiconductor device according to the prior art, the interstitial via hole 25 a is covered with the copper foils 31 a and 36 a in the semiconductor device according to the first embodiment. Consequently, both sides of the double-sided printed circuit board can be blocked and the plating solution can be prevented from invading during manufacture. Thus, manufacture can be performed easily. If it is not necessary to wire bond to a conductor pattern on the interstitial via hole 25 a of the double-sided printed circuit board 16 a and to coat with a solder resist, the step of filling the interstitial via hole 25 a with a resin may be omitted. If it is not necessary to coat with the solder resist, the step of filling the through hole 24 and the interstitial via hole 25 a of the double-sided printed circuit board 15 a with a resin may be omitted. In the case where all the resin filling steps shown in FIG. 8 are omitted, the process can be simplified still more.
Second Embodiment
A method for manufacturing a semiconductor device according to a second embodiment of the present invention will be described below with reference to FIGS. 18 to 33 . By sequentially performing the steps shown in FIGS. 18 to 33 , the semiconductor device according to the second embodiment is completed.
After performing the same steps as the steps shown in FIGS. 1 to 4 , a double-sided printed circuit board 80 shown in FIG. 18 is prepared. The double-sided printed circuit board 80 comprises an insulating substrate 81 . A patterned copper foil 82 is formed on one of main surfaces of the insulating substrate 81 . A copper foil 83 is formed on the other main surface of the insulating substrate 81 . The copper foil 82 is left in a region 85 where a hole 84 is formed such that the hole 84 is covered. The hole 84 penetrates the copper foil 83 and the insulating substrate 81 .
As shown in FIG. 19, an insulating substrate 87 is formed. The insulating substrate 87 has a copper foil 88 formed on one of main surfaces of the substrate 87 , and a concave portion 89 on the other main surface of the substrate.
One of the main surfaces of the double-sided printed circuit board 80 shown in FIG. 18 is bonded to the other main surface of the insulating substrate 87 shown in FIG. 19 by prepreg 91 so that a laminated printed circuit board 90 is formed (see FIG. 20 ). The laminated printed circuit board 90 is also a kind of laminated product comprising an insulating base, an insulating substrate and a copper foil. A chamber 92 is provided in the central portion of the laminated printed circuit board 90 . The laminated printed circuit board 90 is plated with copper so that a copper plated layer 93 is formed on the copper foils 83 and 88 . The copper plated layer 93 is formed on the hole 84 . Consequently, an interstitial via hole 94 for connecting the copper foils 82 and 83 is formed (see FIG. 21 ). At this time, the hole 84 for an interstitial via hole is covered with the copper foil 82 as shown in FIG. 20 . Therefore, a plating solution is prevented from invading the chamber 92 .
As shown in FIG. 22, the interstitial via hole 94 is filled with a resin 95 . A wiring layer 96 formed by the copper foil 83 and the copper plated layer 93 is patterned as shown in FIG. 23 . At this time, the copper foil 83 and the copper plated layer 93 which are provided in a region 97 below the chamber 92 are removed simultaneously (see FIG. 24 ).
In the same manner as the double-sided printed circuit board 80 shown in FIG. 18, a double-sided printed circuit board 100 is prepared. The double-sided printed circuit board 100 comprises an insulating substrate 101 . The insulating substrate 101 has a copper foil 102 patterned on one of its main surfaces, and a copper foil 103 formed on the other main surface. The copper foil 102 is left in a region 105 where a hole 104 is formed such that the hole 104 is covered. The hole 104 penetrates the copper foil 103 and the insulating substrate 101 .
One of the main surfaces of the double-sided printed circuit board 100 shown in FIG. 24 is bonded, by prepreg 107 , to the other main surface side of the double-sided printed circuit board 80 forming the laminated printed circuit board 90 shown in FIG. 23 . Thus, a laminated printed circuit board 106 is formed as an aggregate of the laminated printed circuit board 90 and the double-sided printed circuit board 100 (see FIG. 25 ). The prepreg 107 is not present in a chamber 108 forming a cavity between the double-sided printed circuit board 100 and the laminated printed circuit board 90 in the central portion of the laminated printed circuit board 106 . A hole 109 which penetrates the laminated printed circuit board 106 is formed in regions of the laminated printed circuit board 106 where the prepregs 91 and 107 are present (see FIG. 26 ). Then the laminated printed circuit board 106 on which the hole 109 is formed is plated with copper so that a copper plated layer 112 is formed. Consequently, a through hole 110 and an interstitial via hole 111 are formed (see FIG. 27 ). At this step, the laminated printed circuit board 106 is immersed in a plating solution so as to be plated with copper. As shown in FIG. 26, however, the hole 104 for the interstitial via hole is covered with the copper foil 102 so that the chamber 108 is sealed. Accordingly, the plating solution can be prevented from invading the chambers 92 and 108 .
As shown in FIG. 28, the through hole 110 and the interstitial via hole 111 are filled with a resin 113 . Then, a wiring, layer 114 is patterned (see FIG. 29 ). In that case, the copper foil 88 and the copper plated layers 93 and 112 which are provided in a region 115 except for the through hole 110 and the surroundings thereof are also removed.
Milling is performed on an upper region 116 . A cover supporting portion 122 is opened while a portion on which a cover should be fixed is being formed. Furthermore, an opening 117 is formed in the insulating substrate 81 . After that, nickel-gold plating is performed so that a nickel-gold plated layer 118 is formed on the copper foils 82 and 102 and the copper plated layer 112 (see FIG. 30 ).
As shown in FIG. 31, a wiring layer 120 is patterned on the other main surface side of the double-sided printed circuit board 100 . In that case, the copper foil 103 and the copper plated layer 112 which are provided in a lower region 119 where a cavity is formed are removed. The patterned wiring layer 120 is formed by the copper foil 103 and the copper plated layer 112 . The thickness of the wiring layer 120 is smaller, by the thickness of the copper plated layer 42 , than that of the wiring layer 23 according to the prior art which is being patterned as shown in FIG. 55 . Accordingly, it is easy to make the pattern of the wiring layer 120 finer.
As shown in FIG. 32, an opening 121 is formed in the lower region 119 so that a frame 5 b is completed. A slug 3 is bonded to the frame 5 b with an adhesive 6 .
A chip 2 is bonded to the slug 3 with a die bonding resin 4 , and is connected to the nickel-gold plated layer 118 by a wire 8 . A cover 130 is mounted with a shielding resin 131 so that a package is sealed. Then, a solder ball 7 is formed on the nickel-gold plated layer 118 of the wiring layer 122 . Thus, a semiconductor device 1 b having a printed circuit board type BGA package is completed.
According to the above-mentioned process, copper plating can be performed to form the interstitial via hole 111 and the through hole 110 at the same time. Consequently, one of plating steps can be omitted unlike the prior art in which the interstitial via hole and the through hole are formed separately. For this reason, the manufacture of a printed circuit board type BGA package can be simplified.
An example in which the interstitial via holes 94 and 111 and the through hole 110 are completely filled with the resins 95 and 113 has been described in the second embodiment. The interstitial via hole 94 can be filled with the prepreg 107 when bonding the laminated printed circuit board 90 to the double-sided printed circuit board 100 with the prepreg 107 . For this reason, it is not necessary to fill the interstitial via hole 94 with the resin 95 . By omitting the step of filling the interstitial via hole 94 with the resin 95 , the process of manufacturing the printed circuit board type BGA package can be simplified more.
If it is not necessary to wire bond to a conductor pattern formed on the interstitial via hole 111 and to coat with a solder resist, the step of filling the interstitial via hole 111 with the resin 113 may be omitted. If it is not necessary to coat the through hole 110 with the solder resist, the step of filling the through hole 110 with the resin 113 may be omitted. In the case where the resin filling step shown in FIG. 28 is omitted, the process of manufacturing the printed circuit board type BGA package can be simplified more. The manufacturing cost can be reduced by eliminating all the resin filling steps for the resins 95 and 113 .
The copper foils 82 and 102 are never plated with copper before patterning. The copper foils 83 and 103 are plated with copper only once. For this reason the wiring layers 120 and 123 to 125 which are formed on both sides of the insulating substrates 81 and 101 of the frame 5 b have smaller thicknesses than in the prior art. Consequently, the wiring layers 120 and 123 to 125 are suitable for the formation of a conductor pattern at a small pitch.
While the case in which two double-sided printed circuit boards 80 and 100 are laminated has been described in the second embodiment, it is possible to laminate more double-sided printed circuit boards by adding the following procedure. More specifically, the same double-sided printed circuit board 80 as the double-sided printed circuit board 80 shown in FIG. 18 is prepared and bonded to the double-sided printed circuit board 80 as shown in FIGS. 20 to 23 before the step of FIG. 25 . Then, the same steps are repeated. Thereafter, a further double-sided printed circuit board is prepared and the same steps are repeated. A method for manufacturing a printed circuit board type BGA package having such a structure has the same effects as those of a method for manufacturing a printed circuit board type BGA package having the structure obtained at the manufacturing steps according to the second embodiment.
Third Embodiment
A semiconductor device and a method for manufacturing the semiconductor device according to a third embodiment of the present invention will be described below with reference to FIGS. 34 to 36 .
FIGS. 34 and 35 are plan views showing the structure of the copper foil obtained at the step shown in FIG. 4 according to the first embodiment. A copper foil 140 shown in FIG. 34 corresponds to the copper foil 30 shown in FIG. 4 . Copper foils 142 and 143 shown in FIG. 35 correspond to the copper foil 31 a shown in FIG. 4 .
By way of example, it can also be seen that FIGS. 34 and 35 are plan views showing the structure of the copper foil obtained at the step shown in FIG. 18 according to the second embodiment. In this case, the copper foil 140 shown in FIG. 34 corresponds to the copper foil 82 shown in FIG. 18 . The copper foils 142 and 143 shown in FIG. 35 correspond to the copper foil 83 shown in FIG. 18 .
The copper foil 140 shown in FIG. 34 comprises a circular hole 141 for an interstitial via hole. A source voltage VDD and a grounding voltage GND are given to the copper foils 142 and 143 shown in FIG. 35 . For this reason, an aperture 145 is provided between the copper foils 142 and 143 so as to insulate them from each order. Furthermore, an opening 144 is provided to selectively connect the copper foils 142 and 143 to through holes or the like.
However, when the copper foils 140 and 142 are connected by a plurality of small interstitial via holes, the inductance of the interstitial via holes is increased.
In the semiconductor device according to the first embodiment, the step of forming the hole 60 for the interstitial via hole shown in FIG. 2 is replaced with a step of forming a hole 147 for a slit-shaped interstitial via hole on the periphery of a portion which houses the semiconductor chip 2 as shown in FIG. 36 . Consequently, a printed circuit board type BGA having the slit-shaped interstitial via hole can be manufactured. Thus, if the interstitial via hole is slit-shaped, the inductance of the interstitial via hole can be decreased.
In the case where the slit-shaped interstitial via hole is provided on the double-sided printed circuit board 15 a or 16 a shown in FIG. 4 or 5 in the same manner and the wiring layer 20 a or 23 a is a power source plane or ground plane, the inductance of the power source or ground can be reduced more.
In the semiconductor device according to the second embodiment, the step of preparing the double-sided printed circuit board 80 having the hole 84 for the interstitial via hole shown in FIG. 18 is replaced with the step of forming a hole 147 for a slit-shaped interstitial via hole on the periphery of a portion which houses the semiconductor chip 2 as shown in FIG. 36 . Consequently, a printed circuit board type BGA having the slit-shaped interstitial via hole can be manufactured.
In the case where the interstitial via hole formed on the insulating substrate 81 or 101 shown in FIG. 33 is slit-shaped and the wiring layer 120 or 124 is a power source plane or ground plane, it is possible to obtain a structure having excellent electrical characteristics in which the inductance of the power source or ground can be reduced more.
Fourth Embodiment
A method for manufacturing a semiconductor device according to a fourth embodiment of the present invention will be described below with reference to FIGS. 37 to 39 . In FIG. 37, the reference numeral 38 b designates a laminated printed circuit board, the reference numeral 150 designates a slit-shaped interstitial via hole formed on an insulating substrate 18 , and the same reference numerals designate the same portions as in FIG. 10 . The slit-shaped interstitial via hole 150 can be formed as described in the fourth embodiment. The laminated printed circuit board 38 b shown in FIG. 37 is prepared. For example, the interstitial via hole 150 shown in FIG. 37 is similar to the slit-shaped interstitial via hole 147 shown in FIG. 36 .
Then, an opening 45 a is formed on the upper portion of the laminated printed circuit board 38 b by milling. Each end of the opening 45 a is formed by scraping off one of side walls of the interstitial via hole 150 . Accordingly, the bottom and the other side wall of the interstitial via hole 150 remain after the opening 45 a is formed. Thereafter, the other side wall and the conductor pattern of a wiring layer 19 a which extends to the other side wall are scraped off by means of an end mill or the like such that the bottom of the interstitial via hole 150 remains.
A nickel-gold plated layer 69 is formed also on the bottom of the via hole (see FIG. 38 ). The bottom of the via hole is used as a wire bonding pad of a wiring layer 20 a . Because the interstitial via hole 150 has a bottom, the interstitial via hole 150 can be used as the pad by performing the machining. FIG. 39 shows a section of the semiconductor device in which a wire 8 is connected by using the bottom as the wire bonding pad. Furthermore, the bottom can be used as the wire bonding pad because the interstitial via hole 150 is slit-shaped.
As seen from a comparison between the sections of the semiconductor devices shown in FIGS. 39 and 14, space between the wires 8 connected to the wiring layers 19 a and 20 a can be increased in the direction of the thickness of the semiconductor device so that the short-circuit of the wires 8 can be prevented.
Fifth Embodiment
A method for manufacturing a semiconductor device according to a fifth embodiment of the present invention will be described below with reference to FIGS. 40 to 42 . The steps shown in FIGS. 40 to 42 are substituted for the steps shown in FIGS. 1 to 3 according to the first embodiment. First of all, a double-sided printed circuit board 160 is prepared as shown in FIG. 40 . Then, a copper foil 30 provided on one of sides is patterned. Consequently, the copper foil 30 is removed in a region 161 where a hole for an interstitial via hole is formed (see FIG. 41 ). As shown in FIG. 42, laser beams irradiated from the copper foil 30 side to form a hole 162 for the interstitial via hole.
Thus, the hole 162 for the interstitial via hole is formed so that the step of laminating a copper foil 31 and that of laminating the copper foil 30 can be performed at the same time.
While an example in which a part of the steps of manufacturing a semiconductor device according to the first embodiment is replaced has been described in the fifth embodiment, the steps according to the fifth embodiment can also be used for the second embodiment so that the same effects can be obtained.
While examples in which the copper foil is used have been described in the above-mentioned embodiments, other metallic foils may be used such that the same effects can be obtained.
While the invention has been described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is understood that numerous other modifications and variations can be devised without departing from the scope of the invention. | The minimum spacing between wires disposed on a printed circuit board of a printed circuit board ball grid array package is reduced. Wiring layers are narrower than in the prior art because they are not plated and because only one metal layer is plated on the wiring layers. The narrower wiring layers can be formed easily with small spaces between wires. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to a sewing machine frame made from a synthetic resin in which an arm portion, a tower portion and a bed portion are provided integrally. The present invention also relates to a sewing machine having the sewing machine frame.
In the sewing machine frame, a horizontally extending arm portion supports a reciprocation mechanism for a needle carrying a needle thread, and the tower portion vertically extends from the bed portion for supporting the arm portion in a cantilevered fashion. In the bed portion, a loop taker is supported for trapping a loop of the needle thread carried on the vertically reciprocating needle in order to form a stitch.
In the sewing machine, a smooth stitching operation is required. To this effect, vibration and displacement of a needle tip due to the vertically reciprocating motion of the needle must be reduced or minimized, otherwise a loop seizing beak of the loop taker disposed in the bed portion cannot trap the needle thread loop formed by vertical reciprocation of the sewing needle. Thus, the stitching may be degraded.
In order to avoid this problem, the needle & rotary hook timing must be adequately provided. To this effect, the sewing machine frame must provide high rigidity capable of avoiding deformation or displacement thereof due to reaction force occurring when the needle penetrates a workpiece fabric. Therefore, in the conventional sewing machine, a metallic frame having high rigidity is provided in an interior of a sewing machine cover, and a stitch forming mechanism including a needle vertical reciprocating mechanism and the loop taker is attached to the metallic frame.
However, such a conventional arrangement is costly, bulky and heavy. More specifically, the sewing machine frame has a rigid box shape arrangement in order to provide high rigidity. Further, the frame is made from a metal such as a cast iron or aluminum, which in turn increase weight and size. Further, high skill and elaboration is required for assembling the sewing machine because the stitch forming mechanism must be installed into the metallic frame through a small area opening thereof. This increases assembly cost.
Laid open Japanese Patent Application Kokai No. Hei-11-137880 discloses a sewing machine frame made from a synthetic resin to reduce production cost and to provide a light weight frame. As shown in FIG. 16, the frame 300 has an open end arrangement in a U-shape cross-section in which a bed portion 304 , a tower portion 303 and an arm portion 302 are provided integrally, and a reinforcing plate 301 is fixed between upper and lower portions at the open end of the bed portion 304 .
However, the disclosed sewing machine frame 300 provides a rigidity still lesser than that of the metallic frame. More specifically, as shown in FIG. 16, vertical vibration occurs in the arm portion 302 due to a load exerted along a vertical line containing the needle, the load being caused by the reciprocating motion of the needle during stitching operation. Further, a horizontal swing also occurs at an upper portion of the tower portion 303 during stitching.
Such vibration and swing occur due to the cantilevered support structure of the arm portion 302 with respect to the tower 303 . That is, a combination of the arm portion 303 , the tower portion 303 and the bed portion 304 provides an arcuate recessed wall 305 , and a stress generated by the vertically reciprocating motion of the needle will be concentrated on the wall 305 . However, the wall 305 does not have a sufficient rigidity, and therefore, such unwanted vibration and swing occur to lower stitching quality in comparison with the conventional sewing machine provided with the metallic frame.
SUMMARY OF THE INVENTION
It is an object of the present invention to overcome the above-described problems and to provide a sewing machine frame having a bed portion, a tower portion and an arm portion those integrally with each other and formed of a synthetic resin, yet having high rigidity, and to provide a sewing machine having such an improved sewing machine frame.
This and other objects of the present invention will be attained by a sewing machine frame for use in a sewing machine including a frame member, and a peripheral wall reinforcing rib. The frame member is formed of a synthetic resin and has a bed portion, a tower portion upstanding from the bed portion, and an arm portion extending from the tower portion at a position above the bed portion. The bed portion, the tower portion and the arm portion are formed integrally and provide a concaved peripheral wall defining a stitch working space. The peripheral wall reinforcing rib protrudes from the frame member. The peripheral wall reinforcing rib extends along the peripheral wall and ranges at least from a boundary between the bed portion and the tower portion to a boundary between the tower portion and the arm portion.
In another aspect of the invention, there is provided a sewing machine frame for use in a sewing machine including an outer panel wall, a side wall, a peripheral wall reinforcing rib, and an outer panel wall reinforcing rib. The outer panel wall constitutes a front wall and a rear wall and has a peripheral edge. The side wall protrudes from the peripheral edge to provide a closed space with the outer panel wall and is formed integrally with the outer panel wall with a synthetic resin. A combination of the outer panel wall and the side wall provides a bed portion, a tower portion upstanding from the bed portion, and an arm portion extending from the tower portion and positioned above the bed portion. The side wall has a part providing a concaved peripheral wall which defines a stitch working space surrounded by the bed portion, the tower portion and the arm portion. The peripheral wall reinforcing rib protrudes from the outer panel wall and extends along the peripheral wall. The peripheral wall reinforcing rib ranges at least from a boundary between the bed portion and the tower portion to a boundary between the tower portion and the arm portion. The outer panel wall reinforcing rib protrudes from the outer panel wall for reinforcing the same.
In still another aspect of the invention, there is provided a sewing machine frame including a bed portion, a tower portion upstanding from the bed portion, and an arm portion extending from the tower portion in a cantilevered fashion, a stitch forming mechanism of the sewing machine being assembled in the sewing machine frame. The sewing machine frame includes an integral main frame body, an integral frame cover and a concave wall reinforcing rib. The integral main frame body is made from a synthetic resin and to which the stitch forming mechanism is assembled. The integral main frame body includes a back panel wall having a first peripheral edge, and a first side wall integrally protruding from the first peripheral edge. The integral main frame body provides an arm section, a tower section and a bed section. The integral frame cover is made from a synthetic resin and is attached to the main frame body. The integral frame cover includes a front panel wall having a second peripheral edge, and a second side wall integrally protruding from the second peripheral edge for providing a complementary bed section to form the bed portion with the bed section, a complementary tower section to form the tower portion with the bed section, and a complementary arm section to form the arm portion with the arm section. The first side wall and the second side wall have parts defining a concave wall surroundingly provided by the combination of the arm portion, the tower portion, and the bed portion. The concave wall reinforcing rib extends along the concave wall and ranges at least from a boundary between the bed portion and the tower portion to a boundary between the tower portion and the arm portion.
In still another aspect of the invention, there is provided a sewing machine frame for use in a sewing machine including an outer panel wall, a side wall, and a reinforcing member. The outer panel wall constitutes a front wall and a rear wall. The side wall protrudes from a peripheral edge of the outer panel wall to provide a closed space with the outer panel wall and is formed integrally with the outer panel wall with a synthetic resin. A combination of the outer panel wall and the side wall provides a bed portion extending in its longitudinal direction, a tower portion upstanding from the bed portion, and an arm portion extending in its longitudinal direction from the tower portion and positioned above the bed portion. A congregated area among the bed portion, the tower portion and the arm portion provides a concaved peripheral wall defining a stitch working space of the sewing machine. The reinforcing member is formed integrally with the outer panel wall and has a generally semi-circular hollow cross-section. The reinforcing member is positioned along the peripheral wall and has one end portion positioned in the arm portion and extending in the longitudinal direction thereof, and has another end portion positioned in the bed portion and extending in the longitudinal direction thereof.
In still another aspect of the invention, there is provided a sewing machine frame including a bed portion, a tower portion upstanding from the bed portion, and an arm portion extending from the tower portion in a cantilevered fashion, a stitch forming mechanism of a sewing machine being assembled in the sewing machine frame. The sewing machine frame includes an integral main frame body, an integral frame cover, and a reinforcing member. The integral main frame body is made from a synthetic resin and to which the stitch forming mechanism is assembled. The integral main frame body includes a back panel wall having a peripheral edge, and a side wall integrally protruding from the peripheral edge. The integral main frame body provides an arm section, a tower section and a bed section. The side wall has a part defining a peripheral wall surroundingly provided by the combination of the arm section, the tower section and the bed section. The integral frame cover serves as a front panel wall and is made from a synthetic resin and is attached to the main frame body for providing a complementary bed section to form the bed portion with the bed section, a complementary tower section to form the tower portion with the tower section, and a complementary arm section to form the arm portion with the arm section. The reinforcing member is formed integrally with the main frame body and has a generally semi-circular hollow cross-section. The reinforcing member is positioned along the peripheral wall and has one end portion positioned in the arm section and extending in the longitudinal direction thereof, and has another end portion positioned in the bed section and extending in the longitudinal direction thereof.
In still another aspect of the invention, there is provided a sewing machine including a stitch forming mechanism and any one of the above-described sewing machine frames.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned aspects and other features of the invention are explained in the following description, taken in connection with the accompanying drawing figures wherein:
FIG. 1 is a front view showing the overall construction of a sewing machine comprising a frame according to the preferred embodiment;
FIG. 2 is a side view showing the overall construction of the sewing machine in FIG. 1;
FIG. 3 is a perspective view showing the external appearance of a main frame;
FIG. 4 is a perspective view showing the internal construction of the main frame;
FIG. 5 is a plan view showing the internal construction of the main frame;
FIG. 6 (A) is a cross-sectional view along the plane of the main frame indicated by the arrows A in FIG. 5;
FIG. 6 (B) is a cross-sectional view along the plane of the main frame indicated by the arrows B in FIG. 5;
FIG. 7 (A) is a cross-sectional view along the plane of the main frame indicated by the arrows C in FIG. 5;
FIG. 7 (B) is an enlarged view showing the lower end of the main frame;
FIG. 7 (C) is a cross-sectional view along the plane of the main frame indicated by the arrows D in FIG. 5;
FIG. 8 (A) is a cross-sectional view along the plane of the main frame indicated by the arrows E in FIG. 5;
FIG. 8 (B) is a cross-sectional view along the plane of the main frame indicated by the arrows F in FIG. 5;
FIG. 8 (C) is an enlarge view of a protrusion;
FIG. 8 (D) is a cross-sectional view along the plane of the main frame indicated by the arrows M in FIG. 5;
FIG. 9 (A) is an enlarged plan view showing the main frame from the perspective of the line G in FIG. 5;
FIG. 9 (B) is an enlarged plan view showing the main frame from the perspective of the line H in FIG. 5;
FIG. 10 is a perspective view showing the external appearance of the frame cover;
FIG. 11 is a perspective view showing the internal construction of the frame cover;
FIG. 12 is a plan view showing the internal construction of the frame cover;
FIG. 13 is a cross-sectional view along the plane of the frame cover indicated by the arrows I in FIG. 12;
FIG. 14 (A) is a cross-sectional view along the plane of the frame cover indicated by the arrows J in FIG. 12;
FIG. 14 (B) is an enlarged view showing the lower end of the frame cover;
FIG. 15 (A) is an enlarged plan view along the plane of the frame cover indicated by the arrows K in FIG. 12;
FIG. 15 (B) is an enlarged plan view along the plane of the frame cover indicated by the arrows L in FIG. 12; and
FIG. 16 is a perspective view showing a conventional sewing machine frame.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Structure of a Sewing Machine
A sewing machine frame according to a preferred embodiment of the present invention will be described while referring to the accompanying drawings. First the overall construction of a sewing machine comprising a frame according to the preferred embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a front view, and FIG. 2 is a side view showing the overall construction of the sewing machine comprising a frame 1 according to the preferred embodiment.
As shown in FIG. 1, the frame 1 substantially comprises a bed 8 , a cantilever support 7 provided vertically on the bed 8 , an arm 6 , and an arm 6 cantilevered from the cantilever support 7 above the bed 8 . The bed 8 , the cantilever support 7 , and the arm 6 are integrally formed of a synthetic resin in a substantially C shape.
The frame 1 supports a stitch forming mechanism including a loop taker and a mechanism for driving a needle 16 reciprocally up and down, and constitutes a shell of the sewing machine. In other words, the frame 1 does not need any metallic frame for mounting the stitch forming mechanism. Accordingly, it is possible to manufacture a lighter frame 1 having simplified structure, compared with a conventional metal frame to mount a stitch forming mechanism, covering with a resin cover. The frame 1 may be formed of a synthetic resin material by using a well-known injection molding method.
The synthetic resin material for the frame 1 may be a noncrystalline thermoplastic resin, such as a styrene resin. More specifically, the material may be one or mixture of acrylonitrile-butadiene-styrene copolymer, polystyrene, acrylonitrile-styrene, acrylonitrile-acrylate-styrene, acrylonitrile-ethylene-styrene, chlorinated acrylonitrile-polyethylene-styrene. Of these materials, a resinous matter having acrylonitrile-butadiene-styrene copolymer as the primary component with an inorganic additive of talc or glass bead has good rigidity and a good thermal expansion coefficient. The usage of the above material may eliminate frame coating in the later step due to a good appearance of the frame.
The arm 6 supports a top mechanism 3 for reciprocally driving the needle 16 up and down, the needle 16 retaining needle thread. A motor 2 provided in the cantilever support 7 generates rotational motion. The top mechanism 3 converts this rotational motion to reciprocal motion by means of a crank mechanism to transfer the reciprocal motion to the needle 16 . The top mechanism 3 comprises a spindle 12 , a thread take-up crank 13 , a needle bar holder 14 , a needle bar 15 , and a thread take-up lever link hinge pin 17 mounted in a metal top frame 11 . The top frame 11 is directly attached to the frame 1 by several screws.
Next, the operations of the top mechanism 3 will be described. A rotational driving force generated by the motor 2 is transferred to a large pulley 35 via a motor belt 36 . The rotational driving force transferred to the large pulley 35 is further transferred to the thread take-up crank 13 via an arm shaft 31 and the spindle 12 . The arm shaft 31 is rotatably supported by two bearings 32 , 32 . The spindle 12 is linked to the arm shaft 31 via a coupler. Through the movement of a needle bar crank rod, rotational motion transferred to the thread take-up crank 13 is converted to reciprocal motion of the needle bar 15 that is supported rotatably on the needle bar holder 14 . The needle bar 15 is capable of moving vertically in the needle bar holder 14 . This reciprocal motion is transferred to the needle 16 .
The arm 6 is supported on the top end of the cantilever support 7 , while the bed 8 is connected to the bottom end of the cantilever support 7 . A drive transferring mechanism 5 is disposed in the cantilever support 7 for transferring rotational driving force generated by the motor 2 to the top mechanism 3 housed in the arm 6 and a lower mechanism 4 housed in the bed 8 . The drive transferring mechanism 5 comprises the motor 2 , the large pulley 35 , the motor belt 36 , a pulley 38 , a pulley 39 , and a timing belt. The drive transferring mechanism 5 is directly attached to the frame 1 . The motor 2 is supported by motor supporting brackets 33 that are fixed near the bottom end of the cantilever support 7 .
Next, the operations of the drive transferring mechanism 5 will be described. The rotational driving force provided by the motor 2 is transferred to the large pulley 35 via the motor belt 36 . The rotational driving force transferred to the large pulley 35 is then transferred to the arm shaft 31 rotatably supported by the two bearings 32 , 32 . As described above, this rotational motion is transferred to the top mechanism 3 via the spindle 12 , while this movement is also transferred to the lower mechanism 4 . That is, the pulley 39 is fixed at approximately the center point of the arm shaft 31 . Rotational motion transferred to the pulley 39 is further transferred to the pulley 38 disposed in the bed 8 via the timing belt 41 . A rotary hook shaft 37 is rotatably supported by a bearing 32 . Since the rotary hook shaft 37 is linked to the pulley 38 , the rotary hook shaft 37 rotates in synchronization with the rotations of the arm shaft 31 due to the rotational motion of the pulley 38 .
The cantilever support 7 is formed on one end of the bed 8 . The bed 8 supports a rotary hook 23 constituting a loop taker for catching a thread loop of the needle thread as the needle moves up and down and forming a stitch. The lower mechanism 4 is provided inside the bed 8 for rotating the rotary hook 23 in synchonization with the reciprocal motion of the needle 16 . The lower mechanism 4 comprises a rotary hook shaft 21 , a helical gear 22 , the rotary hook 23 , a helical gear 24 , and the rotary hook shaft 37 mounted on a metal lower frame 20 . The lower frame 20 is mounted directly on the frame 1 by a plurality of screws.
Next, the operations of the lower mechanism 4 will be described. The rotational motion transferred via the timing belt 41 to the pulley 38 is transferred to the helical gear 22 via the rotary hook shaft 37 rotatably supported by the bearing 32 and the rotary hook shaft 21 rotatably supported by two bearings 25 , 25 and linked to the rotary hook shaft 37 via a coupler. As shown in FIG. 2, the helical gear 22 is fixed on the rotary hook shaft 21 . A rotary hook shaft on which the rotary hook 23 is fixed is rotatably supported on the lower frame 20 for rotating beneath the top surface of the bed 8 . The helical gear 24 engaged with the helical gear 22 is fixed to the rotary hook shaft. Accordingly, when the rotary hook shaft 21 rotates, the rotary hook 23 rotates via the helical gear 22 and helical gear 24 . At the same time, A loop seizing beak of the loop taker moves in synchronization with the tip of the needle 16 , and catches the thread loop of the needle thread supported on the needle 16 as the needle 16 moves vertically.
Sewing Machine Frame
In order to execute smooth sewing operations with a sewing machine having the construction described above, it is necessary to minimize vibration caused by the vertical movement of the needle 16 . Simultaneously, displacement of the needle tip caused by deformation of the frame 1 due to the vertical movement of the needle 16 is required to be minimized. This is because large amount of the displacement and the vibration of the needle tip can prevent the loop seizing beak of the loop taker provided in the bed 8 from catching the thread loop, resulting in the formation of an inappropriate stitch. To avoid this, it is necessary to maintain at all times an appropriate needle and rotary hook timing between the loop seizing beak of the rotating rotary hook 23 and the needle 16 that is moved reciprocally up and down. Accordingly, the frame 1 must have high rigidity in order to prevent deformation (displacement) due to a reaction force generated when the needle penetrates a working piece cloth. However, since it is difficult to maintain sufficient rigidity in a frame formed of synthetic resin, the frame 1 of the present embodiment employs various constructions to achieve sufficient rigidity.
As shown in FIG. 2, the frame 1 is formed of a main frame 1 A and a frame cover 1 B along a dividing plane 52 formed in approximately the center of the periphery of the frame 1 when viewed from the end (the dotted line in FIG. 2 ). The main frame 1 A is provided with the stitch forming mechanism including the top mechanism 3 for driving the needle 16 reciprocally up and down and the lower mechanism 4 for rotating the rotary hook 23 is mounted. The frame cover 1 B is coupled to the main frame 1 A to cover the stitch forming mechanism.
The insides of the main frame 1 A and frame cover 1 B are configured to accommodate the top mechanism 3 and the lower mechanism, as shown when the main frame 1 A and frame cover 1 B are in an open state divided along the dividing plane 52 (refer to FIGS. 4 and 11 ). When assembling the sewing machine, the top mechanism 3 and the lower mechanism are first mounted in the main frame 1 A while the main frame 1 A is rendered in an open state. The main frame 1 A and frame cover 1 B are then joined together by inserting screws through couplings 90 , 190 provided in the main frame 1 A and the frame cover 1 B (see FIGS. 4 and 11 ). By simplifying the process for assembling the sewing machine in this way, it is possible to reduce the assembly costs. Since the open area of the frame is closed after assembly, the frame retains sufficient rigidity, and the arm 2 is not easily subject to torsional deformation due to reciprocal motion of the needle 16 .
Main Frame
Next, the main frame 1 A of the frame 1 will be described with reference to FIGS. 3 through 9. FIG. 3 is a perspective view showing the external appearance of the main frame 1 A. FIG. 4 is a perspective view showing the internal construction of the main frame 1 A. FIG. 5 is a plan view showing the internal construction of the main frame 1 A. FIG. 6 (A) is a cross-sectional view along the plane of the main frame 1 A indicated by the arrows A in FIG. 5 . FIG. 6 (B) is a cross-sectional view along the plane of the main frame 1 A indicated by the arrows B in FIG. 5 . FIG. 7 (A) is a cross-sectional view along the plane of the main frame 1 A indicated by the arrows C in FIG. 5 . FIG. 7 (B) is an enlarged view showing the lower end of the main frame 1 A. FIG. 7 (C) is a cross-sectional view along the plane of the main frame 1 A indicated by the arrows D in FIG. 5 . FIG. 8 (A) is a cross-sectional view along the plane of the main frame 1 A indicated by the arrows E in FIG. 5 . FIG. 8 (B) is a cross-sectional view along the plane of the main frame 1 A indicated by the arrows F in FIG. 5 . FIG. 8 (C) is an enlarge view of a protrusion shown in FIG. 8 (B). FIG. 8 (D) is a cross sectional view along the plane of the main frame 1 A indicated by the arrows M. FIG. 9 (A) is an enlarged plan view showing the main frame 1 A from the perspective of the line G in FIG. 5 . FIG. 9 (B) is an enlarged plan view showing the main frame 1 A from the perspective of the line H in FIG. 5 .
As shown in FIG. 3, the main frame 1 A substantially comprises the arm 6 , the cantilever support 7 , and the bed 8 formed integrally. The semicircular space surrounded by the arm 6 , cantilever support 7 , and bed 8 is a space 9 .
In addition, the main frame 1 A comprises a back panel wall 250 constituting a back side of the sewing machine, and side wall 251 extending from a peripheral edge 250 a of the back panel wall 250 . Especially, the surface of the main frame 1 A facing the space 9 is designated as an inner surface wall 51 . The inner surface wall 51 has a rectangular opening 53 that a cloth-pressing lever for fabric (not shown) is passed through.
As shown in FIGS. 1, 4 and 5 , the main frame 1 A is provided with an arrangement for mounting stitch forming mechanism. More specifically, the interior of the arm 6 is provided with a pair of thread take-up shaft supports 140 , 140 for rotatably supporting the thread take-up lever link hinge pin (not shown); a needle bar holder mount 141 on which the needle bar holder 14 is mounted; an upper frame mount 142 on which the top frame 11 is mounted; and a pair of arm shaft supports 144 , 144 for rotatably supporting the arm shaft 31 that transfers the rotational drive force from the motor 2 to the top mechanism 3 . Motor support bracket mounts 146 are mounted in the cantilever support 7 for attaching the motor supporting brackets 33 that fixedly support the motor 2 . Further, the interior of the bed 8 is provided with a pair of lower conducting shaft supports 147 , 147 for rotatably supporting the rotary hook shaft 37 that transfer the rotational drive force from the motor 2 to the lower mechanism 4 , and a lower frame mount 148 on which the lower frame 20 is mounted.
Reinforcing Member
Referring to FIGS. 4 and 5, a reinforcing member 60 is provided around the inner surface wall 51 of the main frame 1 A facing the space 9 surrounded the arm 6 , cantilever support 7 , and bed 8 . The reinforcing member 60 is formed integrally with the back panel wall 250 . One end of the reinforcing member 60 extends along the longitudinal direction of the arm 6 to the point adjacent to the side wall 251 at one end of the arm 6 opposing the cantilever support 7 . The other end of the reinforcing member 60 extends along the longitudinal direction of the bed 8 to the point adjacent to the side wall 251 at one end of the bed 8 opposing the bed 8 . As described above, the reinforcing member 60 comprises three parts: one part placed around the inner surface wall 51 in a semicircle shape, another part placed in a linear manner as if it crosses the arm 6 , and the other part placed in a linear manner as if it crosses the bed 8 . Accordingly, the reinforcing member 60 is placed in a continuous manner to form a U-shape as a whole. The above structure of the reinforcing member 60 reinforces projecting portions of the arm 6 and the bed 8 which extend from the cantilever support 7 .
Referring to FIG. 8 (D), the reinforcing member 60 has a tubular shape with a hollow circular cross-section. This reinforcing member 60 is formed with the back panel wall 250 integrally to project from the inner surface of the back panel wall 250 . The reinforcing member 60 is formed in a tubular shape for the following reasons. As described above, the main frame 1 A is formed according to an injection molding method. In this method, after injecting a molten resinous material in a cavity die shell, the resinous material is cooled. At this time, thicker portions of the molded product harden slower than thinner portions. Since contraction is greater at the thicker portions, shrinkage occurs in those portions. In order to prevent such shrinkage, it is necessary to maintain a uniform thickness in the molded product. For this reason, the reinforcing member 60 is formed in a hollow tubular shape. When forming the frame 1 , the tubular shape of the reinforcing member 60 is formed by injecting an inert fluid, such as argon gas or nitrogen gas, through an injection hole 61 formed at one end of the reinforcing member 60 adjacent to the side wall 251 , and subsequently cooling the reinforcing member 60 .
The above structure of the reinforcing member 60 ensures the rigidity of the inner surface wall 51 facing the space 9 surrounded by the arm 6 , the cantilever support 7 , and the bed 8 on which stress caused by the reciprocating motion of the needle 16 is concentrated. The above structure of the reinforcing member 60 also ensures the rigidity of the back panel wall 250 and the side wall 251 of the arm 6 , cantilever support 7 , and bed 8 adjacent to the inner surface wall 51 . Accordingly, a sewing machine including the main frame 1 A prevents horizontal and vertical vibrations of the main frame 1 A caused by the reciprocating motion of the needle 16 , thereby performing a smooth stitch forming action.
In addition, the reinforcing member 60 has a semicircle hollow section to achieve a light weight and provide sufficient rigidity. The reinforcing member 60 is formed integrally with the back panel wall 250 . Accordingly, process for manufacturing the main frame 1 A is simplified.
In the embodiment described above, the reinforcing member 60 has one end extending to the point adjacent to the side wall 251 placed at the tip of the arm 6 , and the other end extending to the point adjacent to the side wall 251 placed at the tip of the bed 8 . In another embodiment, the reinforcing member 60 may extend to a certain point between the arm 6 and the bed 8 . It is preferable that the reinforcing member 60 is provided around at least the space 9 . In this case, the arrangement of the reinforcing member 60 may have a J-shape, C-shape, or a rectangular shape with one open side.
Auxiliary Reinforcing Member
Referring to FIGS. 4 and 5, the back panel wall 250 of the main frame 1 A has an auxiliary reinforcing member 66 formed integrally therewith. The auxiliary reinforcing member 66 is placed substantially parallel to the reinforcing member 60 outside thereof at a predetermined interval. The auxiliary reinforcing member 66 is placed in a continuous manner described as follows: The auxiliary reinforcing member 66 extends from a certain point between the cantilever support 7 and the side wall 251 at the arm 6 along the longitudinal direction of the arm 6 within the arm 6 to one end of the cantilever support 7 . The auxiliary reinforcing member 66 is then curved in a semicircle shape within the cantilever support 7 to extend to one end of the bed 8 . The auxiliary reinforcing member 66 further extends from the one end of the cantilever support 7 along the bed 8 with in the bed 8 to the point adjacent to the side wall 251 opposing to the cantilever support 7 . As describe above, the parallel arrangement of the reinforcing member 60 and the auxiliary reinforcing member 66 leads to a uniform filling to the interior of the back panel wall 250 between the reinforcing member 60 and the auxiliary reinforcing member 66 with synthetic resin, thereby preventing weld line and shrinkage appearing on the back panel wall 250 . As a result, the main frame 1 A can obtain a good appearance.
Referring to FIG. 7 ( c ), the auxiliary reinforcing member 66 has the substantially semicircle cross section similar to that of the reinforcing member 60 . The auxiliary reinforcing member 66 has a hollow tubular shape having a hollow space 68 within the auxiliary reinforcing member 66 . The auxiliary reinforcing member 66 is formed integrally with the back panel wall 250 in a manner to project from the interior of the back panel wall 250 of the main frame 1 A. The reason why the auxiliary reinforcing member 66 has a tubular shape is the same as that of the reinforcing member 60 . Additionally, a method to form the auxiliary reinforcing member 66 is the same as that of the reinforcing member 60 .
The above arrangement of the auxiliary reinforcing member 66 ensures the rigidity of the back panel wall 250 . Therefore, a sewing machine including the above main frame 1 A can advantageously prevent horizontal and vertical vibrations of the main frame 1 A caused by the reciprocating motion of the needle 16 , thereby performing smooth stitch forming action
In the above embodiment, the main frame 1 A is provided with the reinforcing member 60 and the auxiliary reinforcing member 66 , while the frame cover 1 B does not has any reinforcing member and auxiliary reinforcing member (See FIG. 11 ). The reason why frame cover 1 B has no reinforcing member is as follows: the main frame 1 A accommodates the stitch forming mechanism including the tope mechanism 3 for reciprocating the needle 16 and the lower mechanism 4 for rotating the rotary hook 23 . Therefore, vibrations or displacement are more easily induced to the main frame 1 A than the frame cover 1 B. However, the frame cover 1 B may be provided with a reinforcing member or an auxiliary reinforcing member, if necessary. In that case, the frame cover 1 B obtains stronger rigidity.
Inside Wall Reinforcing Rib
As shown in FIGS. 4 and 5, an inside wall reinforcing rib 70 for reinforcing the inner surface wall 51 of the main frame 1 A facing the space 9 is provided on the inside of the back panel wall 250 around the periphery of the space 9 . A lot of inside wall reinforcing ribs 70 are provided around the periphery of the space 9 from the joint of the arm 6 and the cantilever support 7 to the joint of the cantilever support 7 and the bed 8 .
The inside wall reinforcing rib 70 comprises a partitioning rib 71 spaced from the inner surface 51 and a plurality of intermediate ribs 72 intersecting with the inner surface 51 and partitioning rib 71 . The partitioning rib 71 extends from the inside of the back panel wall 250 and parallel and perpendicularly to the inner surface wall 51 in a continuous manner. The intermediate rib 72 extends from the inside of the back panel wall 250 between the inner surface wall 51 and the partitioning rib 71 at a constant intervals perpendicularly to the back panel wall 250 . The intermediate rib 72 connects the inner surface wall 51 to the partitioning rib 71 , and connects the inner surface wall 51 and the partitioning rib 71 to the back panel wall 250 . The above arrangement of the inner surface wall 51 , the partitioning rib 71 , and the intermediate ribs 72 provides a plurality of cells 73 in the space between the inner surface 51 and partitioning rib 71 . The intermediate ribs 72 are arranged radially from a center point located in the space 9 , because the inner surface wall 51 surrounding the space 9 has a semicircle shape. Accordingly, each intermediate rib 72 intersects the inner surface 51 and partitioning rib 71 at a perpendicular angle. Thus, the arrangement of the ribs is optimized, thereby reinforcing the inner surface wall 51 advantageously.
The above structure of the inside wall reinforcing ribs 70 provides the rigidity equal to that of the inner surface wall 51 having a considerable thickness. In other words, the above structure of the inside wall reinforcing ribs 70 ensures the rigidity over the back panel wall 250 from the area adjacent to the joint of the arm 6 and the cantilever support 7 , through the cantilever support 7 , to the area adjacent to the joint of the cantilever support 7 and the bed 8 . A sewing machine having the main frame 1 A can prevent horizontal and vertical vibrations of the main frame 1 A caused by the reciprocating motion of the needle 16 , thereby performing a smooth stitch forming action.
In the above embodiment, the inside wall reinforcing ribs 70 are provided on the back panel wall 250 from the joint of the arm 6 and the cantilever support 7 through the 7 through the 7 to the joint of the cantilever support 7 and the bed 8 . In another embodiment, the inside wall reinforcing rib 70 may be formed over the whole of the inner surface wall 51 . In the above embodiment, a lot of intermediate ribs 72 are provided. However, in another embodiment, the number of the intermediate ribs 72 may be only one or a few. Each of the intermediate ribs 72 may be coupled or crossed to each other, so that the resultant arrangement of the intermediate ribs 72 may have honeycomb or diagram shape.
As described above, the hollow reinforcing member 60 having a substantially semicircle shape is formed integrally with the back panel wall 250 around the inner surface wall 51 . In other words, both the reinforcing member 60 and the inside wall reinforcing rib 70 are formed at the substantially same positions on the inner surface wall 51 . Especially, the reinforcing member 60 is located near the back panel wall 250 inside of the inside wall reinforcing rib 70 . The inside wall reinforcing rib 70 projects from the surface of the reinforcing member 60 . The above structure is necessary to obtain considerable reinforcement, because stress induced by the reciprocating motion of the needle 16 is concentrated on the inner surface wall 51 . In addition, the space around the inner surface wall 51 has sufficient spare room because the stitch forming mechanism is not mounted. Therefore, the inside wall reinforcing rib 70 having a considerable height can be formed.
Outside Wall Reinforcing Rib
As shown in FIGS. 4 and 5, outside wall reinforcing ribs 80 are formed in a matrix shape over nearly the entire inside of the back panel wall 250 . The outside wall reinforcing rib 80 projects from the inside of the back panel wall 250 . The outside wall reinforcing rib 80 is formed of vertical ribs 81 vertically oriented when the sewing machine is placed on a working surface, and horizontal ribs 82 oriented horizontally when the sewing machine is in the same position. As shown in FIGS. 6 (A) and 6 (B), these vertical ribs 81 and horizontal ribs 82 are approximately perpendicular to the back panel wall 250 . The ends of the vertical ribs 81 and horizontal ribs 82 are joined with the side wall 251 on the side portions of the main frame 1 A. The spaces surrounded by pairs of intersecting vertical ribs 81 , 81 and horizontal ribs 82 , 82 form approximately square or rectangular shaped cells 83 . Hence, a plurality of cells 83 are formed on the back side of the back panel wall 250 .
Among the cells 83 , the outside wall reinforcing rib 80 defining a cell 83 having a wider area is formed to have a higher height from the back panel wall 250 , compared to a cell 83 having a narrower area. The above structure of the cell 83 will be explained with respect to a wider cell 83 A located on the right side of the arm conducting shaft supports 144 in the cantilever support 7 (see FIGS. 4 and 5 ), and a narrower cell 83 B located on the lower-right side of the needle bar holder mount 141 in the arm 6 (see FIGS. 4 and 5 ).
As shown in FIG. 5, the vertical length X of the wider cell 83 A is identical to the vertical length U of the narrower cell 83 B. On the other hand, the horizontal length Y of the wider cell 83 A is longer more than two times of the horizontal length V of the narrower cell 83 B. Thus, the area of the wider cell 83 A is wider than that of the narrower cell 83 B.
Referring to FIG. 6 (A), the height Z from the 250 of the outside wall reinforcing rib 80 constituting the wider cell 83 A (horizontal rib 82 ) is higher than the height W from the back panel wall 250 of the outside wall reinforcing rib 80 constituting the narrower cell 83 B (vertical rib 81 ). In the case where the outside wall reinforcing ribs 80 have different height from each other due to requirements for a design of the main frame 1 A, the wider area of the higher outside wall reinforcing rib 80 and the narrower area of the narrower outside wall reinforcing rib 80 lead to the uniform rigidity over the whole of the back panel wall 250 . Accordingly, the action of stress on the particular point on the back panel wall 250 can be avoided. Thus, the main frame 1 A ensures considerable rigidity as a whole.
The outside wall reinforcing rib 80 on the accommodating part for the stitch forming mechanism in the arm 6 or the bed 8 has a lower height from the back panel wall 250 than those of the outside wall reinforcing ribs 80 on the inside of the back panel wall 250 other than the accommodating part. In other words, as described above, the narrower cell 83 B is located on the right-lower side of the needle bar holder mount 141 for mounting the needle bar holder 14 constituting the tope mechanism 3 , thereby corresponding to the part accommodating the stitch forming mechanism. Therefore, the outside wall reinforcing rib 80 (vertical rib 81 ) has a relatively lower height W from the back panel wall 250 so as to face the stitch forming mechanism at a closer distance. On the other hand, the wider cell 83 A is not a part for accommodating the stitch forming mechanism. Accordingly, as described above, the outside wall reinforcing rib 80 (horizontal rib 82 ) has a relatively higher height Z form the back panel wall 250 . However, the above structure may lead to insufficient rigidity over the part for accommodating the stitch forming mechanism. To overcome the above problem, the narrower area of the cell 83 , that is, the formation of the narrower cell 83 B, results in the increase of the rigidity thereof. The resultant rigidity is substantially the same as that of the wider cell 83 A. Accordingly, the concentration of stress to a certain point of the back panel wall 250 can be prevented, so that the main frame 1 A can obtain sufficient rigidity.
The above arrangement of the outside wall reinforcing rib 80 ensures the sufficient rigidity of the back panel wall 250 , thereby minimizing or restricting distortion appearing on the back panel wall 250 of the arm 6 due to the reciprocating motion of the needle 16 . The above arrangement of the outside wall reinforcing rib 80 also minimizes distortion appearing on the back panel wall 250 of the cantilever support 7 and the bed 8 due to the distortion of the arm 6 . In this embodiment, the outside wall reinforcing ribs 80 extend in vertical and horizontal directions on the back panel wall 250 to define the cells 83 . This arrangement results in the sufficient rigidity of the back panel wall 250 in the case where the outside wall reinforcing rib 80 is not allowed to have a higher height in order that the main frame 1 A accommodates the stitch forming mechanism. Accordingly, a sewing machine having the above main frame 1 A can prevent vertical and horizontal vibrations of the main frame 1 A caused by the reciprocating motion of the needle 16 , thereby performing a smooth stitch forming action.
In another embodiment, the outside wall reinforcing rib 80 may not be formed over the whole back panel wall 250 , but be formed over only the part of the back panel wall 250 which needs sufficient rigidity of the back panel wall 250 for accommodating the stitch forming mechanism. In another embodiment, the outside wall reinforcing ribs 80 may be arranged in order that the cells 83 have hexagonal or octagonal shapes.
It should be noted that the inside wall reinforcing rib 70 has a higher height from the back panel wall 250 than that of the outside wall reinforcing rib 80 . More specifically, as shown in FIG. 8 (A), at the base end of the arm 6 , the inside wall reinforcing rib 70 is formed at a height from the back panel wall 250 reaching the dividing plane 52 . In contrast, the vertical ribs 81 reach approximately halfway to the dividing plane 52 from the back panel wall 250 . As shown in FIG. 8 (B), in the center portion of the cantilever support 7 , the intermediate ribs 72 have a height from the sidewall 50 reaching the dividing plane 52 . In contrast, the horizontal ribs 82 reach less than half the height of the dividing plane 52 from the sidewall 50 . A high rigidity is necessary for the inner surface wall 51 since stress generated by the vertical movement of the needle 16 is concentrated in this area. On the other hand, these height differences are necessary to maintain space at the inside of the back panel wall 250 for accommodating the stitch forming mechanism including the top mechanism 3 and the lower mechanism 4 .
Couplings
As shown in FIGS. 4 and 5, a plurality of couplings 90 , 92 , 94 , and 96 are provided in the back panel wall 250 of the main frame 1 A for joining the main frame 1 A to the frame cover 1 B. The coupling 90 is formed near the inner surface wall 51 in the area adjacent to the joint of the bed 8 and the cantilever support 7 . More specially, the coupling 90 is placed in the vicinity of the inside wall reinforcing rib 70 and the reinforcing member 60 . The above arrangement of the coupling 90 is aimed at preventing distortion of the arm 6 and the cantilever support 7 which causes swings of the top portion of the cantilever support 7 during the reciprocating motion of the needle 16 . The coupling 92 is formed near the inner surface wall 51 at the joint area of the arm 6 and the cantilever support 7 . More particularly, the coupling 92 is placed in the vicinity of the inside wall reinforcing rib 70 and the reinforcing member 60 . The coupling 94 is formed near the inner surface wall 51 in the vicinity of the end of the inside wall reinforcing rib 70 near the arm 6 . The couplings 92 , 94 are placed on the circumference of the semicircle of the space 9 at constant intervals with respect to the coupling 90 . A plurality of couplings 96 are formed on the sides and the corners of the inside of the back panel wall 250 in order to couple the main frame 1 A and the frame cover 1 B by a uniform pressure.
Screw holes 91 , 93 , 95 , and 97 are formed inside the couplings 90 , 92 , 94 , and 96 . The main frame 1 A and frame cover 1 B can be detachably joined together by inserting screws (not shown) in the screw holes 91 , 93 , 95 , and 97 when the couplings 90 , 92 , 94 , and 96 are aligned with couplings 190 , 192 , 194 , and 196 (see FIG. 11) provided in corresponding positions on the frame cover 1 B. Accordingly, the sewing machine is easily assembled by mounting the stitch forming mechanism to the main frame 1 A, and then screwing the frame cover 1 B to the main frame 1 A, thereby enabling cost reductions. In the case of maintenance, only undoing the screws leads to remove of the frame cover 1 B from the main frame 1 A, so that all the stitch forming mechanism is exposed. Therefore, the maintenance work is facilitated. In the present embodiment, screws are used to join the main frame 1 A to the frame cover 1 B, but bolts and nuts may also be used in place of the screws.
When stress induced by the reciprocating motion of the needle 16 forces the inner surface wall 51 of the main frame 1 A and an inner surface wall 161 of the frame cover 1 B to relatively move in a vertical or horizontal directions, relative movement of the main frame 1 A and the frame cover 1 B is restricted because a plurality of couplings 190 , 192 , and 194 (see FIG. 11) are arranged around the inner surface walls 51 , 161 . Therefore, the inner surface wall 51 of the main frame 1 A remains contact with the inner surface wall 161 of the frame cover 1 B. A appropriate coupling between the main frame 1 A and the frame cover 1 B is maintained. Stress is transmitted from the main frame 1 A including the stitch forming mechanism which generates vibrations to the frame cover 1 B through the inner surface walls 51 , 161 which are contact to each other, thereby dispersing over the whole frame 1 . The stress dispersion ensures the sufficient rigidity of the frame 1 . As a result, a sewing machine including the frame 1 can prevent vertical vibrations and horizontal swings of the frame 1 induced by the reciprocating motion of the needle 16 , thereby performing a smooth stitch forming action.
In another embodiment, two or more than four couplings may be formed around the inner surface wall 51 of the main frame 1 A.
Protrusions
As shown in FIG. 4, protrusions 100 , 101 , 102 , and 103 are formed on the main frame 1 A at the dividing plane 52 . These protrusions 100 , 101 , 102 , and 103 engage with engaging units 111 , 112 , 113 , and 114 provided on the frame cover 1 B at the dividing plane 52 (see FIG. 11) when the main frame 1 A is joined with the frame cover 1 B. The protrusions 100 , 101 , 102 , and 103 are aimed at limiting the relative movement of the main frame 1 A and frame cover 1 B in the horizontal direction.
Next, the reason that the sewing machine frame of the present invention is configured in this way will be described. As mentioned earlier, a swing effect occurs in the horizontal direction in the top portion of the cantilever support 7 due to the vertical movement of the needle 16 . When this happens, the main frame 1 A and frame cover 1 B can move relative to one another in the horizontal direction, shifting their relative positions. When this positional shifting occurs, a reliable joined state cannot be maintained, resulting in insufficient rigidity, thereby promoting vibrations and displacement in the frame 1 . Moreover, the main frame 1 A and frame cover 1 B are joined by screws through considerable pressure, causing a large frictional coefficient. As a result, when the relative position of the main frame 1 A and frame cover 1 B shifts, they do not easily return to their original positions. The above construction is employed because it is necessary to prevent such shifting in the relative position of the main frame 1 A and frame cover 1 B from occurring. With this construction, it is possible to maintain sufficient rigidity in the frame 1 .
As shown in FIG. 9 (A), the protrusion 100 protrudes from the bottom of the arm 6 at the dividing plane 52 substantially perpendicular to the frame cover 1 B and near the border between the horizontal portion on which the mechanism for reciprocally driving the needle 16 is supported and the semicircular portion by which the space 9 is formed. An opening 143 is formed in the front end of the arm 6 from which the reciprocally driving mechanism protrudes downward. The protrusion 100 is positioned to one side of the opening 143 . The protrusion 100 fits in the engaging unit 111 provided on the arm 6 of the frame cover 1 B (see FIG. 11 ). This configuration prevents relative movement of the main frame 1 A and frame cover 1 B generated by vibrations and displacement at the dividing plane 52 of arm 6 .
As shown in FIG. 9 (B), the protrusions 101 and 102 protrude from the top of the bed 8 at the dividing plane 52 , that is, at both ends of an opening 149 approximately perpendicular to the frame cover 1 B. The opening 149 is aimed for exposing rotary hook 23 . The protrusions 101 , 102 are fitted into engaging units 112 , 113 provided in the bed 8 of the frame cover 1 B (see FIG. 11 ). The above arrangement can prevent relative movement of both the main frame 1 A and the frame cover 1 B caused by vibrations and displacement at the dividing plane 52 of the bed 8 in the main frame 1 A and the frame cover 1 B.
Referring to FIGS. 8 (B), 8 (C), the protrusion 103 protrudes to the frame cover 1 B being coupled at a predetermined point on the dividing plane 52 around the space 9 . The predetermined point is placed on the intermediate rib 72 constituting the inside wall reinforcing rib 70 in the vicinity of a cross point with the inner surface wall 51 around the space 9 . The protrusion 103 fits a channel-shaped engaging unit 114 (see FIG. 11) provided the periphery of the frame cover 1 B facing the space 9 . The above structure prevents vibrations and displacement at the dividing plane 52 around space 9 , thereby restricting relative movement of the coupled main frame 1 A and frame cover 1 B.
Referring to FIG. 9 (A), an engaging unit 110 for receiving the protrusion 104 (see FIG. 11) protruding from the dividing plane 52 below the arm 6 of the frame cover 1 B. The place of the engaging unit 110 is on the dividing plane 52 below the arm 6 of the main frame 1 A. The above arrangement prevents vibrations and displacement at the dividing plane 52 of the arm 6 of the coupled main frame 1 A and frame cover 1 B, thereby restricting relative movement of the main frame 1 A and frame cover 1 B.
Top Edge
As shown in FIGS. 4 and 7 (A), a top edge 120 is formed across the top of the main frame 1 A for contacting the frame cover 1 B. A raised step 121 is formed across nearly the entire top edge 120 , the bottom of raised step 121 protruding toward the frame cover 1 B. The protruding portion of the raised step 121 fits into a recessed step 126 formed in a top edge 125 of the frame cover 1 B for contacting the main frame 1 A (see FIG. 11 ). By engaging the raised step 121 with the recessed step 126 from above, this construction can limit the relative movement of the main frame 1 A in the upward direction.
Next, the reason that the sewing machine frame of the present invention is configured in this way will be described. As mentioned earlier, the portion of the main frame 1 A near the arm 6 vibrates in the vertical direction due to the vertical movement of the needle 16 . In particular, the main frame 1 A on which the top mechanism 3 is mounted for supporting the needle 16 tends to move in the upward direction. When this happens, the main frame 1 A and frame cover 1 B can move relative to one another in the vertical direction, shifting their relative positions. When this positional shifting occurs, a reliable joined state cannot be maintained, resulting in insufficient rigidity, thereby promoting vibrations and displacement in the frame 1 . Moreover, the main frame 1 A and frame cover 1 B are joined by screws through considerable pressure, causing a large frictional coefficient. As a result, when the relative position of the main frame 1 A and frame cover 1 B shifts, they do not easily return to their original positions. The above construction is employed because it is necessary to prevent such shifting in the relative position of the main frame 1 A and frame cover 1 B from occurring. With this construction, it is possible to maintain sufficient rigidity in the frame 1 .
While the raised step 121 in the present embodiment is formed across nearly the entire length of the top edge 120 of the main frame 1 A that contacts the frame cover 1 B, it is not necessary for the raised step 121 to span the entire length of the top edge 120 . In view of the reason described above for forming the raised step 121 , however, it is desirable that the raised step 121 be formed on the top edge 120 at least at portions of the main frame 1 A corresponding to the arm 6 . Similarly, the recessed step 126 (see FIG. 11) should be formed on the top edge 125 at least on portions of the frame cover 1 B that correspond to the arm 6 . With this construction, it is possible to achieve sufficient rigidity for the arm 6 .
A bottom edge 130 is formed across the bottom of the main frame 1 A for contacting the frame cover 1 B. A raised step 131 is formed across nearly the entire length of the bottom edge 130 , the top of the raised step 131 protruding toward the frame cover 1 B. As shown in FIG. 7 (B), the raised step 131 comprises an insertion part 132 for inserting into a recessed step 136 (see FIG. 11) formed on a bottom edge 135 of the frame cover 1 B for contacting the main frame 1 A; a sliding surface 133 for guiding the raised step 131 into the recessed step 136 ; and an engaging wall 134 for engaging in the recessed step 136 after the recessed step 136 has been slid to a prescribed position. By inserting the insertion part 132 in the recessed step 136 of the frame cover 1 B and engaging the sliding surface 133 with the bottom of the recessed step 136 , it is possible to limit relative movement of the main frame 1 A in the downward direction.
Next, the reason that the sewing machine frame of the present invention is configured in this way will be described. As mentioned earlier, the portion of the main frame 1 A tends to move upward due to the vertical movement of the needle 16 . When this happens, the bed 8 of the frame cover 1 B engaged with the main frame 1 A attempts to move downward relative to the main frame 1 A. As a result, the frame cover 1 B shifts vertically from the main frame 1 A, promoting the generation of vibrations and displacement in the frame 1 . Hence, it is necessary to prevent such shifting in the relative position of the main frame 1 A and frame cover 1 B from occurring. With this construction, it is possible to maintain sufficient rigidity in the frame 1 .
While the raised step 131 in the present embodiment is formed across nearly the entire length of the bottom edge 130 of the main frame 1 A that contacts the frame cover 1 B, it is not necessary for the raised step 131 to span the entire length of the bottom edge 130 . In view of the reason described above for forming the raised step 131 , however, it is desirable that the raised step 131 be formed on the bottom edge 130 at least at portions of the main frame 1 A corresponding to the bed 8 . Similarly, the recessed step 136 (see FIG. 11) should be formed on the bottom edge 135 at least on portions of the frame cover 1 B that correspond to the bed 8 . With this construction, it is possible to achieve sufficient rigidity for the bed 8 .
Here, the sliding surface 133 of the raised step 131 is retracted further internally than the back panel wall 250 of the main frame 1 A. When the recessed step 136 of the frame cover 1 B overlaps this portion, the sidewall of the main frame 1 A and frame cover 1 B become the same height. Accordingly, by engaging the main frame 1 A with the frame cover 1 B, the sidewall of the main frame 1 A and frame cover 1 B forms a continuous surface at this point, improving the appearance of the frame 1 .
While a detailed construction of the raised step 121 described above is not shown in the drawings, this construction is similar to the raised step 131 of the bottom edge 130 shown in FIG. 7 (B). However, the raised step 121 is vertically symmetrical to the raised step 131 .
Flame Cover
Next, the frame cover 1 B of the frame 1 will be described with reference to FIG. 10 through needle bar 15 . FIG. 10 is a perspective view showing the external appearance of the frame cover 1 B. FIG. 11 is a perspective view showing the internal construction of the frame cover 1 B. FIG. 12 is a plan view showing the internal construction of the frame cover 1 B. FIG. 13 is a cross-sectional view along the plane of the frame cover 1 B indicated by the arrows I in FIG. 12 . FIG. 14 (A) is a cross-sectional view along the plane of the frame cover 1 B indicated by the arrows J in FIG. 12 . FIG. 14 (B) is an enlarged view showing the lower end of the frame cover 1 B. FIG. 15 (A) is an enlarged plan view along the plane of the frame cover 1 B indicated by the arrows K in FIG. 12 . FIG. 15 (B) is an enlarged plan view along the plane of the frame cover 1 B indicated by the arrows L in FIG. 12 .
As shown in FIG. 10, the frame cover 1 B comprises the arm 6 , cantilever support 7 , and bed 8 , and is integrally formed of a synthetic resin with the arm 6 , cantilever support 7 , and bed 8 . The semicircular area surrounded by the arm 6 , cantilever support 7 , and bed 8 is the space 9 the main frame 1 A substantially comprises the arm 6 , the cantilever support 7 , and the bed 8 formed integrally. The semicircular space surrounded by the arm 6 , cantilever support 7 , and bed 8 is a space 9 .
In addition, the frame cover 1 B comprises a front panel wall 252 constituting a front side of the sewing machine, and side wall 253 extending from a peripheral edge 252 a of the front panel wall 252 . Especially, the surface of the frame cover 1 B facing the space 9 is designated as an inner surface wall 161 . A side portion of the arm 6 is provided with a thread cassette mount 203 in which a thread cassette including different kinds of thread.
Inside Wall Reinforcing Rib
As shown in FIGS. 11 and 12, an inside wall reinforcing rib 170 for reinforcing the inner surface wall 161 of the frame cover 1 B facing the space 9 is provided on the inside of the front panel wall 252 around the periphery of the space 9 . A lot of inside wall reinforcing ribs 170 are provided around the periphery of the space 9 from the joint of the arm 6 and the cantilever support 7 to the joint of the cantilever support 7 and the bed 8 in order to surround the inner surface wall 161 .
The inside wall reinforcing rib 170 comprises a partitioning rib 171 spaced from the inner surface 161 and a plurality of intermediate ribs 172 intersecting with the inner surface 161 and partitioning rib 171 . The partitioning rib 171 extends from the inside of the front panel wall 252 and parallel and perpendicularly to the inner surface wall 161 in a continuous manner. The intermediate rib 172 extends from the inside of the front panel wall 252 between the inner surface wall 161 and the partitioning rib 171 at a constant intervals perpendicularly to the front panel wall 252 . The intermediate rib 172 connects the inner surface wall 161 to the partitioning rib 171 , and connects the inner surface wall 161 and the partitioning rib 171 to the front panel wall 252 . The above arrangement of the inner surface wall 161 , the partitioning rib 171 , and the intermediate ribs 172 provides a plurality of cells 173 in the space between the inner surface 161 and partitioning rib 171 . The intermediate ribs 172 are arranged radially from a center point located in the space 9 , because the inner surface wall 161 surrounding the space 9 has a semicircle shape. Accordingly, each intermediate rib 172 intersects the inner surface 161 and partitioning rib 171 at a perpendicular angle. Thus, the arrangement of the ribs is optimized, thereby reinforcing the inner surface wall 161 advantageously.
The above structure of the inside wall reinforcing ribs 170 provides the rigidity equal to that of the inner surface wall 161 having a considerable thickness. In other words, the above structure of the inside wall reinforcing ribs 170 ensures the rigidity over the front panel wall 252 from the area adjacent to the joint of the arm 6 and the cantilever support 7 , through the cantilever support 7 , to the area adjacent to the joint of the cantilever support 7 and the bed 8 . A sewing machine having the frame cover 1 B can prevent horizontal vibrations and swings of the frame cover 1 B caused by the reciprocating motion of the needle 16 , thereby performing a smooth stitch forming action.
In the above embodiment, the inside wall reinforcing ribs 170 are provided on the front panel wall 252 from the joint of the arm 6 and the cantilever support 7 through the 7 through the 7 to the joint of the cantilever support 7 and the bed 8 . In another embodiment, the inside wall reinforcing rib 170 may be formed over the whole of the inner surface wall 161 . In the above embodiment, a lot of intermediate ribs 172 are provided. However, in another embodiment, the number of the intermediate ribs 172 may be only one or a few. Each of the intermediate ribs 172 may be coupled or crossed to each other, so that the resultant arrangement of the intermediate ribs 172 may have a honeycomb or diagram shape.
In order to further support the partitioning rib 171 of the inside wall reinforcing ribs 170 , a supplemental concave wall reinforcing rib 177 is provided outside of the inside wall reinforcing ribs 170 . The supplemental concave wall reinforcing rib 177 comprises an auxiliary partitioning rib 174 and a plurality of auxiliary intermediate ribs 175 . The auxiliary partitioning rib 174 is provided in a continuous manner along the partitioning rib 171 , while being spaced from the partitioning rib 171 . The auxiliary intermediate ribs 175 intersect the partitioning rib 171 and partitioning rib 174 at predetermined intervals, and form a plurality of cells or compartments 176 between the partitioning rib 171 and partitioning rib 174 . This construction attains further rigidity of the inner surface 161 of the space 9 . In another embodiment, supplemental concave wall reinforcing ribs may be provided outside of the inside wall reinforcing rib 70 of the main frame 1 A, if the main frame 1 A has sufficient spare space.
Outside Wall Reinforcing Rib
As shown in FIGS. 11 and 12, outside wall reinforcing ribs 180 are formed in a matrix shape over nearly the entire inside of the front panel wall 252 . The outside wall reinforcing rib 180 projects from the inside of the front panel wall 252 . The outside wall reinforcing rib 180 is formed of vertical ribs 181 vertically oriented when the sewing machine is placed on a working surface, and horizontal ribs 182 oriented horizontally when the sewing machine is in the same position. As shown in FIGS. 13 and 14 (A), these vertical ribs 181 and horizontal ribs 182 are approximately perpendicular to the front panel wall 252 . The ends of the vertical ribs 181 and horizontal ribs 182 are joined with the side wall 253 on the side portions of the frame cover 1 B. The upper ends of the vertical ribs 181 are not coupled to the side wall 253 . This is because the upper portion of the frame cover 1 B needs sufficient space to accommodate thread cassettes and an LED display substrate. The spaces surrounded by pairs of intersecting vertical ribs 181 , 181 and horizontal ribs 182 , 182 form approximately square or rectangular shaped cells 183 . Hence, a plurality of cells 183 are formed on the back side of the front panel wall 252 .
Among the cells 183 , the outside wall reinforcing rib 180 defining a cell 183 having a wider area is formed to have a higher height from the front panel wall 252 , compared to a cell 183 having a narrower area. The outside wall reinforcing rib 180 on the accommodating part for the stitch forming mechanism in the arm 6 or the bed 8 has a lower height from the front panel wall 252 than those of the outside wall reinforcing ribs 180 on the inside of the front panel wall 252 other than the accommodating part. The cells 183 in the vicinity of the accommodating part for the stitch forming mechanism have narrower areas than those of the cells 183 provided on the area other than the accommodating part. The reason the above arrangement has been adopted is the same as that of the main frame 1 A, so that detailed explanation will be omitted.
The above arrangement of the outside wall reinforcing rib 180 ensures the sufficient rigidity of the front panel wall 252 , thereby minimizing or restricting distortion appearing on the front panel wall 252 of the arm 6 due to the reciprocating motion of the needle 16 . The above arrangement of the outside wall reinforcing rib 180 also minimizes distortion appearing on the front panel wall 252 of the cantilever support 7 and the bed 8 due to the distortion of the arm 6 . In this embodiment, the outside wall reinforcing ribs 180 extend in vertical and horizontal directions on the front panel wall 252 to define the cells 183 . This arrangement results in the sufficient rigidity of the front panel wall 252 in the case where the outside wall reinforcing rib 180 is not allowed to have a higher height in order that the frame cover 1 B accommodates the stitch forming mechanism. Accordingly, a sewing machine having the above frame cover 1 B can prevent vertical and horizontal vibrations of the frame cover 1 B caused by the reciprocating motion of the needle 16 , thereby performing a smooth stitch forming action.
It should be noted that the inside wall reinforcing rib 170 has a higher height from the front panel wall 252 than that of the outside wall reinforcing rib 180 . More specifically, as shown in FIG. 14 (A), at the base end of the arm 6 , the inside wall reinforcing rib 170 is formed at a height from the front panel wall 252 reaching the dividing plane 52 . In contrast, the vertical ribs 181 reach approximately halfway to the dividing plane 52 from the front panel wall 252 . The reason is as follows: the inner surface wall 161 needs sufficient rigidity, because stress induced by the reciprocating motion of the needle 16 generally tends to concentrate on the inner surface wall 161 .
In another embodiment, the outside wall reinforcing rib 180 may be provided on the only part of the frame cover 1 B. Alternatively, the frame cover 1 B may have no outside wall reinforcing rib 180 . The frame cover 1 B does not need so high rigidity as that of the main frame 1 A.
Couplings
As shown in FIGS. 11 and 12, a plurality of couplings 190 , 192 , 194 , and 196 are provided in the front panel wall 252 of the main frame 1 A for joining the main frame 1 A to the frame cover 1 B. The coupling 190 , 192 , 194 , and 196 are placed at positions corresponding to the positions of the couplings 90 , 92 , 94 , and 94 of the main frame 1 A. The coupling 190 is formed near the inner surface wall 161 in the area adjacent to the joint of the bed 8 and the cantilever support 7 . More specially, the coupling 190 is placed in the vicinity of the inside wall reinforcing rib 170 formed outside of the inner surface wall 161 . The above arrangement of the coupling 190 is aimed at preventing distortion of the arm 6 and the cantilever support 7 which causes swings of the top portion of the cantilever support 7 during the reciprocating motion of the needle 16 . The coupling 192 is formed near the inner surface wall 161 at the joint area of the arm 6 and the cantilever support 7 . More particularly, the coupling 192 is placed in the vicinity of the inside wall reinforcing rib 170 outside of the inner surface wall 161 . The coupling 194 is formed near the inner surface wall 161 in the vicinity of the end of the inside wall reinforcing rib 170 near the arm 6 . The couplings 192 , 194 are placed on the circumference of the semicircle of the space 9 at constant intervals with respect to the coupling 190 . A plurality of couplings 196 are formed on the sides and the corners of the inside of the back panel wall 250 in order to couple the main frame 1 A and the frame cover 1 B by a uniform pressure.
Screw holes 191 , 193 , 195 , and 197 are formed inside the couplings 190 , 192 , 194 , and 196 . The main frame 1 A and frame cover 1 B can be detachably joined together by inserting screws (not shown) in the screw holes 191 , 193 , 195 , and 197 when the couplings 190 , 192 , 194 , and 196 are aligned with couplings 90 , 92 , 94 , and 96 provided in corresponding positions on the main frame 1 A.
Engaging Unit
As shown in FIG. 11, engaging units 111 , 112 , 113 , and 114 are formed in the frame cover 1 B at the dividing plane 52 . These engaging units 111 , 112 , 113 , and 114 engage with protrusions 100 , 101 , 102 , and 103 provided on the main frame 1 A at the dividing plane 52 (see FIG. 4) when the main frame 1 A is joined with the frame cover 1 B and function to limit the relative movement of the main frame 1 A and frame cover 1 B in the horizontal direction.
As shown in FIG. 15 (A), the engaging unit 111 is recessed in the bottom of the arm 6 on the frame cover 1 B at the dividing plane 52 and on one side of an opening 200 through which the mechanism for reciprocally driving the needle 16 protrudes downward. The engaging unit 111 engages with the protrusion 100 (see FIG. 4) formed on the arm 6 of the main frame 1 A. This construction limits relative movement of the main frame 1 A and frame cover 1 B generated by vibrations and displacement at the dividing plane 52 of the arm 6 .
As shown in FIG. 15 (B), the engaging units 112 and 113 are recessed in the top of the bed 8 at the dividing plane 52 and on both sides of an opening 202 for exposing the rotary hook 23 . The engaging units 112 and 113 engage with the protrusions 101 and 102 formed on the bed 8 of the main frame 1 A (see FIG. 4 ). This construction restricts relative movement of the main frame 1 A and frame cover 1 B caused by vibrations and displacement at the dividing plane 52 of the bed 8 .
As shown in FIG. 11, the engaging unit 114 is formed in a continuous channel on the inner surface 161 of the space 9 . The protrusions 103 provided on the main frame 1 A (see FIG. 4) engage with this channel portion. This construction restricts relative movement of the main frame 1 A and frame cover 1 B caused by vibrations and displacement at the dividing plane 52 of the space 9 .
Protrusion
As shown in FIG. 15 (A), the protrusion 104 is formed on the bottom of the arm 6 of the frame cover 1 B at the dividing plane 52 and on the opposite side of the opening 200 as that in which the engaging unit 111 is formed. The protrusion 104 protrudes substantially perpendicularly to the frame cover 1 B. The protrusion 104 fits in the engaging unit 110 provided on the arm 6 of the main frame 1 A (see FIG. 4 ). This construction restricts relative movement of the main frame 1 A and frame cover 1 B caused by vibrations and displacement at the dividing plane 52 of the arm 6 .
Recessed Top Edge
As shown in FIG. 14 (A), the recessed step 126 is formed across nearly the entire top edge 125 on the frame cover 1 B that contacts the main frame 1 A for accommodating the raised step 121 formed on the top edge 120 of the main frame 1 A and engaging the raised step 121 from the top. As shown in FIG. 14 (B), the recessed step 126 comprises an engaging wall 127 protruding toward the main frame 1 A for engaging the raised step 121 of the main frame 1 A when the raised step 121 is guided to a prescribed position; a sliding surface 128 for guiding the raised step 121 ; and an accommodating portion 129 for accommodating the insertion part of the raised step 121 . By accommodating the insertion part of the raised step 121 in the accommodating portion 129 and when the sliding surface of the raised step 121 engages with the sliding surface 128 from above, it is possible to limit relative movement of the main frame 1 A in the upward direction.
The recessed step 136 is formed across nearly the entire bottom edge 135 of the frame cover 1 B that contacts the main frame 1 A for accommodating the raised step 131 formed on the bottom edge 130 of the main frame 1 A and engaging the raised step 131 from below. While a detailed construction of the recessed step 136 is not shown in the drawings, this construction is basically the same as the recessed step 126 of the top edge 125 shown in FIG. 14 (B). However, the recessed step 136 is vertically symmetrical to the recessed step 126 . By engaging the raised step 131 with the recessed step 136 , it is possible to limit the relative movement of the main frame 1 A in the downward direction.
It is understood that the foregoing description and accompanying drawings set forth the preferred embodiments of the invention at the present time. Various modifications, additions and alternative designs will, of course, become apparent to those skilled in the art in light of the foregoing teachings without departing from the spirit and scope of the disclosed invention. Thus, it should be appreciated that the invention is not limited to the disclosed embodiments but may be practiced within the full scope of the appended claims. | A sewing machine frame having reinforced structure for use in a sewing machine is disclosed. The sewing machine frame has a frame member formed of a synthetic resin and having a bed portion, a tower portion upstanding from the bed portion, and an arm portion extending from the tower portion at a position above the bed portion, the bed portion, the tower portion and the arm portion being formed integrally and providing a concaved peripheral wall defining a stitch working space. The sewing machine frame is characterized by a peripheral wall reinforcing rib protruding from the frame member, the peripheral wall reinforcing rib extending along the peripheral wall and ranging at least from a boundary between the bed portion and the tower portion to a boundary between the tower portion and the arm portion. | 3 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to antennas and associated methods for communication and, more particularly, to antennas systems having active polarization correction and associated communication methods.
BACKGROUND OF THE INVENTION
[0002] Antennas are widely utilized in order to transmit and receive a variety of signals. For example, antennas are widely utilized in radio frequency communication systems. Radio frequency antennas are commonly capable of simultaneously transmitting and/or receiving signals having different polarizations, such as orthogonally polarized signals, in order to increase the transmission and/or reception capacity of the antenna. In order to effectively transmit and/or receive signals that are orthogonally polarized, an antenna must have relatively high polarization purity such that there is minimal interference between the orthogonally polarized signals. In some applications, for example, the required cross-polarization isolation may be 30 dB or more.
[0003] One common type of antenna utilized for high-data rate Communications with moving platforms is a phased array antenna. Among other advantages, phased array antennas are capable of communicating simultaneously with two or more spatially separate sources. In addition, phased array antennas are relatively easy to install, operate and maintain on moving platforms such as aircraft, ships and motor vehicles since they generally have a relatively low profile, are capable of rapidly tracking and have no moving parts.
[0004] Phased array antennas generally include a number of identical radiating elements and a beam former connected to the radiating elements. Each element may include a phase shifter and/or a time delay circuit. In addition, each element may include an amplifier, if desired. In one phased array antenna, each element includes a phase shifter and groups of elements are interconnected by a time delay circuit. By adjusting the phase shift of each element and the time delay of each group of elements, the beam transmitted and/or received by the phased array antenna may be formed electronically and steered without physical movement of the antenna aperture over a wide instantaneous bandwidth. Moreover, by incorporating multiple beam formers and multiple phase shifters and time delay circuits associated with each radiating element, a phased array antenna that is capable of forming multiple simultaneous independent beams may be constructed.
[0005] Phase array antennas are capable of transmitting and/or receiving signals having any desired polarization. In this regard, a schematic representation of the architecture of a phased array antenna capable of sensing signals having either circular polarization or arbitrarily oriented linear polarization is shown in FIG. 1. A phased array antenna having the architecture depicted in FIG. 1 includes a plurality of modules 1 , each of which includes two amplifiers 2 connected to the orthogonal radiating elements 3 . The output of each amplifier connected to a 90° hybrid 4 which forms left circular polarization out of one port and right circular polarization out of the other port. Each port is connected to a phase shifter 5 which, in turn, is connected to an independent beam forming network 6 . The output of each beam former is therefore a left or right circularly polarized (CP) beam that is redirected independently of the other beam. A phased array antenna having the construction depicted in FIG. 1 may also operate in a linearly polarized (LP) mode. In this mode, the two beams are co-pointed and the beam former outputs are recombined in a quadrature hybrid 7 to recover two orthogonal linear polarizations from a single source. By controlling the two phase shifts 5 to have a constant offset therebetween, the two orthogonal linear polarization axes may be spatially rotated so as to be aligned with the polarization axes of a source, such as a satellite that radiates orthogonal linearly polarized signals Although phased array antennas offer a number of advantages, phased array antennas, in particular, and electronically scanned antennas, in general, are typically unable to provide the degree of polarization purity over the entire range of scan angles as that provided by at least some mechanically scanned antennas. The limitations with respect to the polarization purity of electronically scanned antennas are created by construction constraints within the modules, inherent radiating element cross-polarization characteristics and the active impedance to which a module is subjected once a module is placed in an array. Notably, this disadvantageous cross-polarization coupling between signals having orthogonal polarizations is within the antenna itself and is independent of any cross-coupling between signals having orthogonal polarizations that may occur in the propagation medium.
[0006] For signals transmitted and/or received in a near broadside direction, the cross-polarization isolation is determined largely by the degree of cross-coupling between orthogonal radiating elements. While phased array antennas can be constructed with near broadside polarization isolation approaching that of mechanically scanned antennas, the cost of the modules that must be constructed generally increases substantially. Unfortunately, as the scan angle increases away from broadside, the cross-polarization isolation degrades due to divergence between the E and H-plane active impedances seen by each module in the array. The degree of divergence typically increases monotonically with elevation scan and varies smoothly and periodically with azimuth scan. At an elevation scan of 60°, for example, the degree of degradation of the cross-polarization isolation relative to that provided near broadside will vary as the antenna is scanned in an azimuthal direction by as much as 10 dB. The internal coupling between the orthogonally polarized signals within an antenna 20 may be graphically depicted as shown in FIG. 2. In this regard, the antenna is represented by the combination of two blocks, one block 22 depicting an ideal antenna having no internal coupling between the orthogonally polarized signals and another block 24 depicting the internal coupling between the orthogonally polarized signals. As will be apparent, although the antenna is depicted for purposes of discussion as being separated into two boxes, the antenna cannot physically be separated in the same manner as the internal coupling between the orthogonally polarized signals is inherent within the antenna as a result of its construction and design.
[0007] Referring to FIG. 2, the antenna 20 includes a pair of terminals 26 and at least one pair of orthogonally polarized radiating elements 28 . In the transmission mode, two orthogonally polarized signals T 1 and T 2 are presented at the antenna terminals and are amplified by the ideal antenna 22 by a gain designated A. These amplified signals are then subjected to undesirable cross-polarization coupling as represented by block 24 . As indicated within block 24 , the ratio of the cross-coupled voltage to the signal voltage is designated δ. As such, the signals transmitted by the dual orthogonally polarized radiating element are not merely the amplified inputs designated AT 1 and AT 2 , but are instead more complex signals in which each signal includes components having both polarizations. In the illustrated example, the radiating element designed to radiate signals having the first polarization p 1 actually radiates a signal defined as A[T 1 (1−δ 2 ) 1/2 {circumflex over (p)} 1 +δT 2 {circumflex over (p)} 2 ], while the radiating element designed to radiate signals having the second polarization p 2 actually radiates a signal represented as A[δT 1 {circumflex over (p)} 1 +(1−δ 2 ) 1/2 T 2 {circumflex over (p)} 2 ].
[0008] Similarly, in the reception mode, dual orthogonally polarized signals are presented to the dual orthogonally polarized radiating elements 28 as designated R 1 1 and R 2 2 . Instead of being merely amplified by the antenna and presented at the antenna terminals 26 , the internal cross-polarization coupling causes each of the signals to include components having both polarizations. As such, the signals actually presented to the antenna terminals are represented as A[R 1 (1−δ 2 ) 1/2 +δR 2 ] and A[δR 1 +(1−δ 2 ) 1/2 R 2 ].
[0009] Several techniques have been developed to improve the polarization purity of phased array antennas at high scan angles. Each technique attempts to improve the polarization purity in a passive manner and is somewhat effective, although practical limitations generally prevent the desired degree of polarization purity from being achieved.
[0010] One technique to improve polarization purity is to reduce the spacing between radiating elements. The degree to which the spacing between radiating elements may be reduced is limited, however, by packaging issues and by a loss in the gain that the radiating elements may provide that results from a decrease in the spacing. In this regard, the area available in which to package the phase shift and amplification circuitry decreases proportional to the square of the decrease in element spacing. The spacing between radiating elements for wide scan performance must be less than 0.577λ, where λ is the wavelength of the signals transmitted and/or received by the antenna. Particularly at frequencies above 10 GHz, however, it is difficult and expensive to appreciably decrease the spacing between the radiating elements to less than 0.577λ, especially in packaging schemes that are relatively thin and planar. By incorporating a vertical packaging architecture, the spacing between the radiating elements may be decreased somewhat more, but only at the expense of a generally disadvantageous increase in the thickness of the antenna. As the radiating elements become more closely spaced, the gain which each radiating element is capable of providing also decreases. This decrease in the gain that each radiating element is capable of providing may require that the number of radiating elements be increased in order to provide the same overall intended performance, i.e., Gain to noise temperature (G/T) for reception antennas and Effective Isotropic Radiated Power (EIRP) for transmission antennas. As will be apparent, an increase in the number of radiating elements correspondingly increases the cost of the antenna and, with respect to phased array antennas, also increases the power consumption of the antenna. Accordingly, high polarization purity cannot be obtained as a practical matter at high scan angles simply by reducing the spacing between the radiating elements.
[0011] Another technique to improve the polarization purity of electronically scanned antennas, such as phased array antennas, is to provide a wide angle impedance (WAIM) layer that is disposed over the radiating elements. A WAIM layer is constructed from a plurality of dielectric layers that serve to improve the cross-polarization isolation at relatively high scan angles. Unfortunately, the number of dielectric layers that would be required in order to effectively suppress cross-polarization coupling over an azimuth scan of 360° far exceeds the number that may be practically employed.
[0012] Even those phased array antennas, having a relatively small spacing between the radiating elements and including a WAIM layer are unable to provide sufficient cross-polarization isolation at some of the scan angles for some applications. For example, a phased array antenna capable of providing cross-polarization isolation in the broadside direction approaching 28 dB may generally only be able to provide cross-polarization isolation of about 15 dB at an elevation scan angle of 60° and at the worst case azimuth angle. As such, it would be desired to provide an antenna system which provides enhanced polarization isolation between signals transmitted and/or received having orthogonal polarizations.
SUMMARY OF THE INVENTION
[0013] An antenna system and an associated method are provided that are capable of providing improved cross-polarization isolation, thereby negating the otherwise deleterious effects of cross-coupling between orthogonally polarized signals that occur within a dual orthogonally polarized antenna, such as a phased array antenna. Thus, the antenna system can more reliably transmit and/or receive dual orthogonally polarized signals over a wide range of elevation and azimuth scan angles.
[0014] The antenna of one advantageous embodiment includes a dual orthogonally polarized antenna, such as a phased array antenna, capable of supporting propagation of signals having two orthogonal polarizations. The antenna permits different predetermined amounts of internal coupling between the orthogonally polarized signals at different scan angles. The antenna system of this embodiment also includes a cross-polarization cancellation element associated with the antenna for modifying the orthogonally polarized signals to compensate for the internal coupling. The cross-polarization cancellation element modifies the orthogonally polarized signals at different scan angles based on the different predetermined amounts of internal coupling between the orthogonally polarized signals at different scan angles.
[0015] The antenna system may also include a processor for directing the cross-polarization cancellation element to provide appropriate modifications to the orthogonally polarized signals and a memory device, accessible by the processor, for storing data representing modifications to be provided by the cross-polarization cancellation element to the orthogonally polarized signals at different scan angles. In addition to variances based upon the scan angle, the data stored by the memory device may also be dependent upon the frequency of the orthogonally polarized signals.
[0016] In embodiments in which the dual orthogonally polarized antenna is a phased array antenna, the phased array antenna may include a pair of input/output ports for providing signals having a respective polarization. As such, the cross-polarization cancellation element of one embodiment may be connected to the pair of input/output ports. The phased array antenna also includes a plurality of modules, each including a pair of dual orthogonally polarized radiating elements. As such, the cross-polarization element need not be connected to the pair of input/output ports of the phased array antenna. Instead, the antenna system of another embodiment may include a plurality of cross-polarization cancellation elements associated with respective modules of the phased array antenna.
[0017] In one embodiment in which the cross-polarization cancellation element is connected to the input/output ports of one antenna, the cross-polarization cancellation element includes a first leg extending from the first input/output port to the second input/output port, and a second leg extending from the second input/output port to the first input/output port. Each leg includes an adjustable amplifier and an adjustable phase shifter for controllably adjusting the amplitude and phase, respectively, of the signals diverted from one input/output port to the other input/output port. By appropriately adjusting the amplitude and phase, the internal coupling between the orthogonally polarized signals that is permitted by the antenna may be corrected.
[0018] According to another embodiment in which the cross-polarization cancellation element is connected to the input/output ports of the antenna, the cross-polarization cancellation element includes first and second legs connected to the first and second input/output ports, respectively. Each leg includes an adjustable, i.e., variable gain, amplifier or an adjustable attenuator (hereinafter generally termed an adjustable amplifier) and an adjustable phase shifter for controllably adjusting the amplitude and phase, respectively, of the signals at the respective input/output port. In addition, the first and second legs of the cross-polarization cancellation element may include at least one quadrature hybrid connected between the legs. By appropriately adjusting the amplitude and phase of the signals, the cross-polarization cancellation element may similarly compensate for the internal coupling between the orthogonally polarized signals. Thus, the antenna system of the foregoing embodiments provide open loop control of the cross-polarization coupling.
[0019] The antenna system of another embodiment includes both a reception antenna for receiving signals having two orthogonal polarizations and a transmission antenna for transmitting signals having two orthogonal polarizations. Both the reception antenna and the transmission antenna may be phased array antennas. In addition, both the reception antenna and the transmission antenna permit internal coupling between the orthogonally polarized signals. The antenna system of this embodiment also includes first and second cross-polarization cancellation elements associated with the reception and transmission antennas, respectively, for modifying the orthogonally polarized signals to compensate for the internal coupling. Each cross-polarization cancellation element includes a delta port and a sum port. In addition, each cross-polarization cancellation element includes at least one phase shifter for modifying the phase of at least some of the orthogonally polarized signals. Each cross-polarization cancellation element may also include an adjustable amplifier for controllably adjusting the amplitude of at least some of the orthogonally polarized signals.
[0020] According to this embodiment, the antenna system also includes a processor for setting the phase shift and the amplitude imparted by at least one phase shifter and the amplifier of the first cross-polarization cancellation element, respectively, typically in an iterative manner, such that a null is provided at the delta port. The processor then sets at least one phase shifter and amplifier of the second cross-polarization cancellation element to impart the same phase shift and amplification, respectively. Thus, the antenna system of this embodiment effectively employs closed loop feedback in order to compensate for the internal coupling between the orthogonally polarized signals permitted by the reception and transmission antennas.
[0021] The antenna of this embodiment may include first and second input/output ports for providing signals having a respective polarization. As such, each cross-polarization cancellation element is connected to the first and second input/output ports of the respective antenna. Each cross-polarization cancellation element may include the first and second legs connected to the first and second input/output ports, respectively, of the respective antenna. Each leg includes an adjustable amplifier and an adjustable phase shifter for controllably adjusting the amplitude and phase, respectively, of the signals at the respective input/output port. The first and second legs of each cross-polarization cancellation element of this embodiment may also include at least one quadrature hybrid connected therebetween such that the cross-polarization cancellation element may compensate for the internal coupling between the orthogonally polarized signals that is permitted by the respective antenna.
[0022] In operation, orthogonally polarized signals may be received by the reception antenna with the phase of the received signals then being selectively shifted and, in advantageous embodiments, the amplitude of the received signals also being selectively adjusted such that a null is provided at the delta port of the cross-polarization cancellation element. The phase shift and, in advantageous embodiments, the amplitude adjustment imparted upon the transmitted signals is then set to be equal to the phase shift and the adjustment in amplitude imparted upon the received signals. The orthogonally polarized signals may then be transmitted via the transmission antenna with the phase shift and amplitude adjustment compensating for the internal coupling between the orthogonally polarized signals that is permitted by the transmission antenna.
[0023] Accordingly, the antenna system and associated method of the present invention provide active correction for internal coupling between the orthogonally polarized signals permitted by the dual orthogonally polarized antenna, such as a phased array antenna. As such, the antenna can transmit and/or receive dual orthogonally polarized signals across a full range of scan angles without concern as to the degradation of the polarization purity of the signals. Additionally, the antenna system of the present invention provides active polarization correction without substantially increasing the cost of the antenna system and without significantly impacting the size or packaging requirements of the antenna. Nevertheless, the antenna system of the present invention can be used with any of the conventional passive measures described herein, to provide additional polarization purity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a schematic representation of a module of a conventional phased array antenna;
[0025] [0025]FIG. 2 is a block diagram illustrating the impact of spurious cross-polarization upon an ideal antenna;
[0026] [0026]FIG. 3 is a block diagram representing the cross-polarization cancellation provided by the antenna system and method of one embodiment to the present invention;
[0027] [0027]FIG. 4 is another block diagram representation of the cross-polarization cancellation provided by the antenna system and method of one embodiment of the present invention in which the cross-polarization coupling and the cross-polarization correction are represented by matrices;
[0028] [0028]FIG. 5 is a representation of an antenna system according to one embodiment of the present invention;
[0029] [0029]FIG. 6 is a representation of an antenna system according to another embodiment of the present invention;
[0030] [0030]FIG. 7 is a representation of an antenna system according to yet another embodiment of the present invention;
[0031] [0031]FIG. 8 is a representation of the relationship between the input and output of dual orthogonally polarized antennas which mathematically defines the internal coupling between the orthogonally polarized signals; and
[0032] [0032]FIG. 9 is a block diagram representing an antenna system according to a further embodiment to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout.
[0034] According to the present invention, an antenna system 30 and an associated method are provided for correcting or otherwise providing compensation for undesirable cross-polarization coupling within an antenna. While the antenna system of the present invention may include a wide variety of dual orthogonally polarized antennas 32 , the antenna system of the present invention generally includes a dual orthogonally polarized antenna that is electronically steerable, such as a phased array antenna. As explained below in detail, the cross-polarization cancellation provided by the antenna system and method of the present invention can be considered to pre-depolarize signals that are otherwise presented in orthogonally polarized form to the antenna. As these pre-depolarized signals pass through the antenna, the cross-polarization coupling inherent in the antenna will essentially restore the pre-depolarized signals to being orthogonally polarized. As will be apparent, this technique is equivalent to injecting a portion of the undesirable, cross-polarized signal into a co-polarized channel with the undesirable cross-polarized signal having the proper amplitude relationship to and being out of phase with the undesired signal. Moreover, the cross-polarization cancellation provided by the antenna system and method of the present invention may be employed individually or in combination with one or more passive techniques for providing cross-polarization cancellation, such as the reduction in the spacing of the dual orthogonally polarized radiating elements or the addition of a WAIM layer over the radiating elements.
[0035] In addition to the dual orthogonally polarized antenna 32 , the antenna system 30 of the present invention includes a cross-polarization cancellation element 34 associated with the antenna. The cross-polarization cancellation element modifies the orthogonally polarized signals to compensate for internal coupling between the orthogonally polarized signals. As noted above, this internal cross-polarized coupling occurs within the antenna and is independent of any cross-polarization coupling that may occur in the propagation medium or elsewhere in the communications system. As shown in FIG. 3, the cross-polarization cancellation element may be depicted as an addition to the antenna system otherwise depicted in FIG. 2. In this regard, the dual orthogonally polarized antenna may be represented as an ideal antenna having no internal cross-polarization coupling and a block representing the cross-polarization coupling permitted by the dual orthogonally polarized antenna. As described above in conjunction with FIG. 2, this cross-polarization coupling causes the signals transmitted and/or received by the antenna to no longer be of a single polarization, but instead to have components of both orthogonal polarizations. According to the present invention and as explained in more detail below, the cross-polarization cancellation element offsets the internal cross-polarization coupling permitted within the antenna such that the signals transmitted and/or received by the antenna system are orthogonally polarized with little, if any, cross-coupling therebetween.
[0036] In the illustrated embodiment (FIG. 3) in which the internal cross-polarization coupling permitted by the antenna 32 has complex number designation δ, the cross-polarization cancellation element preferably injects a signal having having complex designation β that is related to δ as follows:
β=−δ (1)
[0037] For a dual orthogonally polarized antenna 32 having internal cross-polarization coupling represented by δ, the internal cross-polarization coupling can be represented by the polarization matrix C as follows:
C = [ ( 1 - δ 2 ) 1 / 2 δ δ ( 1 - δ 2 ) 1 / 2 ] ( 2 )
[0038] In the embodiment in which the cross-polarization coupling permitted by the cross-polarization cancellation element 34 is equal and opposite to the internal cross-polarization coupling permitted by the antenna 32 , orthogonally polarized signals provided to the antenna for transmission are initially subjected to cross-polarization coupling by the cross-polarization cancellation element and are then amplified and subjected to internal cross-polarization coupling as shown in FIG. 3 such that the signals actually transmitted by the antenna are amplified and remain orthogonally polarized. Similarly, orthogonally polarized signals received by the antenna are amplified and are subjected to both the internal cross-polarization coupling and the equal and opposite cross-polarization coupling provided by the cross-polarization cancellation element such that the resulting signals that appear at the terminals of the antenna are orthogonally polarized. Thus, the signals that are transmitted and/or received by the antenna system do not include components of both polarizations, but are instead orthogonally polarized.
[0039] Since the cross-polarization provided by the cross-polarization cancellation element 34 is equal and opposite to the internal cross-polarization coupling permitted by the antenna 32 , the cross-polarization provided by the cross-polarization cancellation element may be represented by a cross-polarization compensation matrix D as follows:
D = 1 1 - 2 δ 2 [ ( 1 - δ 2 ) 1 / 2 - δ - δ ( 1 - δ 2 ) 1 / 2 ] ( 3 )
[0040] As such, FIG. 3 can be redrawn as shown in FIG. 4 in which the cross-polarization coupling is represented by respective matrices.
[0041] The cross-polarization cancellation element 34 may be applied at the antenna terminals as shown in FIGS. 3 and 4 or to the individual modules of a phased array antenna. By applying the cross-polarization cancellation to the antenna terminals, the antenna 32 will need to have signals having both polarizations available at the terminals For a phased array antenna, the antenna will therefore generally be required to have two beam formers, one associated with each antenna terminal. Applying the cross-polarization cancellation to each module would eliminate the requirement of having two beam forming networks, but would require a plurality of cross-polarization cancellation elements, one of which is associated with each module of the phased array antenna. Generally, the cross-polarization cancellation element will be applied at the antenna terminals and the antenna system 30 and method of the present invention will therefore be described in conjunction with antenna systems having a cross-polarization cancellation element applied at the antenna terminals for purposes of illustration and explanation, but not of limitation.
[0042] An antenna system 30 according to one embodiment of the present invention is depicted in FIG. 5. As shown, the antenna system includes a dual orthogonally polarized antenna 32 having a pair of input/output ports 36 . In the reception mode, the antenna is adapted to receive signals having a first polarization via a first port and signals having a second orthogonal polarization via a second port. Conversely, in the transmission mode, the antenna is adapted to provide signals having a first polarization via the first port and signals having a second orthogonal polarization via the second port. According to this embodiment, the cross-polarization cancellation element 34 includes a first leg 38 that extends from the first port to the second port, and a second leg 40 extending from the second port to the first port. The first and second legs may be connected to the respective ports by means of directional couplers. As such, a predetermined portion of the signals otherwise available at the first port is diverted via the first leg by a first directional coupler 42 and is then added to the signals available at the second port by a second directional coupler 44 . Similarly, a portion of the signals otherwise available at the second port are diverted via the second leg by a third directional coupler 46 and are then added to the signals available at the first port by a fourth directional coupler 48 . As shown in FIG. 5, each leg includes an adjustable gain amplifier 50 and an adjustable phase shifter 52 for controllably adjusting the amplitude and phase, respectively, of the signals diverted from one port to the other port. By appropriately adjusting the amplitude and phase of the diverted signals, the cross-polarization cancellation element effectively compensates for the internal cross-polarization coupling between the orthogonally polarized signals that is permitted by the antenna.
[0043] Typically, the antenna system 30 includes a processor, a controller or the like for controllably setting the amplification and the phase shift of the diverted signals such that the amplitude and phase of the cross-polarization correction is equal and opposite to the internal cross-polarization coupling permitted by the antenna 32 . As described above, the internal cross-polarization coupling permitted by the antenna may repeatably vary based upon the scan angle and the frequency of the signals. As such, appropriate settings for the amplitude and phase shift of the diverted signals may be determined in advance for a variety of scan angles and frequencies, such as at an antenna measurement range, and stored in a memory device or the like. As such, once the antenna system is placed in operation for transmitting signals of a particular wavelength and at a particular scan angle, the processor, controller or the like may recall the appropriate amplitude and phase adjustment to be provided by the cross-polarization cancellation element in order to offset or compensate for the internal cross-polarization coupling between the orthogonally polarized signals permitted by the antenna.
[0044] A more general representation of an antenna system 30 including a cross-polarization cancellation element 34 according to the present invention is depicted in FIG. 6. As described above in conjunction with FIG. 5, the cross-polarization correction element is connected to the antenna terminals or ports. In this regard, the cross-polarization cancellation element can include first and second legs 38 , 40 connected to the first and second ports, respectively. Each leg again includes an adjustable attenuator or amplifier 50 , and an adjustable phase shifter 54 for controllably adjusting the amplitude and phase, respectively, of the signals at the respective ports. As indicated by FIG. 6, the adjustable attenuator or amplifier and adjustable phase shifter of each leg are adapted to collectively apply a complex weight to the signals otherwise available at the respective ports, in this case a common signal V. In this regard, the adjustable attenuator or amplifier and adjustable phase shifter of the first leg weight the signals at the first port by complex weight W 1 and the adjustable amplifier and the adjustable phase shifter of the second leg weights the signals at the second port by complex weight W 2 wherein W 1 and W 2 are defined as follows:
W
1
=|W
1
|e
jφ
1
W 2 =|W 2 |e jφ 2 (4)
[0045] wherein |W 1 | and |W 2 | are magnitudes and φ 1 and φ 2 are phases of complex weights W 1 and W 2 respectively. The complex weights are based upon the elements of the cross-polarization cancellation matrix designated d 11 , d 12 , d 12 , d 21 and d 22 , and the orthogonally polarized signals T 1 and T 2 that are desired in order to effectively offset the internal cross-polarization coupling permitted by the antenna 32 . With reference to FIGS. 3 and 4, the complex weights W 1 and W 2 can therefore be defined as follows:
W
1
=T
1
d
11
+T
2
d
12
W 2 =T 1 d 21 +T 2 d 22 (5)
[0046] As described above in conjunction with the embodiment of FIG. 5, the complex weights W 1 and W 2 generally vary depending upon the scan angle and the frequency of the signals transmitted and/or received by the antenna 32 . As such, appropriate values for the complex weights may be determined in advance for each scan angle and frequency of interest. These predetermined complex weights may be stored in a memory device. As such, the antenna system 30 may also include a processor, a controller or the like for accessing the memory device and obtaining the appropriate complex weights based upon the current scan angle and the current frequency of the signals being transmitted and/or received by the antenna and thereafter appropriately adjusting the amplitude and phase of the signals at the first and second ports of the antenna.
[0047] The antenna system 30 of yet another embodiment is depicted in FIG. 7 which is capable of readily applying the complex weights to the signals at the first and second ports of the antenna 32 . In instances in which the antenna is designed to transmit dual orthogonal polarized signals, designated T 1 and T 2 , a cross-polarization cancellation element 34 may be designed to receive the dual orthogonal polarized signals T 1 and T 2 and to provide signals V 1 and V 2 to the first and second ports, respectively, of the antenna. In this regard, the relationship between the signals provided by the cross-polarization correction element to the first and second ports of the antenna and the original dual orthogonal polarized signal is defined as follows:
V 1 =c[T 1 cos(γ/2)+ T 2 sin(γ/2)] e jφ 1
V 2 =c[T 1 sin(γ/2)+T 2 cos(γ/2)] e jφ 2 (6)
[0048] wherein c is a constant and γ=γ 2 −γ 1 . As explained herein below, γ effectively controls the relative amplitude of the signals while φ=φ 2 −φ 1 effectively controls the relative phase between the signals.
[0049] In the embodiment of FIG. 7, the cross-polarization cancellation element 34 again includes first and second legs 38 , 40 connected to the first and second ports, respectively, of the antenna 32 . Each leg includes an adjustable phase shifter 50 for controllably adjusting the relative phase φ of the signals at the respective port. In addition, each leg includes an adjustable phase shifter γ 50 for controllably adjusting the relative amplitude between the two signals at the array input ports. In addition, the first and second legs of the cross-polarization cancellation element include at least one and, more preferably, a pair of quadrature hybrids 54 connected therebetween. In the illustrated embodiment, for example, a cross-polarization correction element includes a first quadrature hybrid having a pair of inputs to which the input signals T 1 and T 2 are applied and a pair of outputs connected to the adjustable phase shifters of the first and second legs, respectively. Additionally, the cross-polarization correction element of the illustrated embodiment includes a second quadrature hybrid connected between the adjustable amplifiers and the adjustable phase shifters of the first and second legs. By comparison of equations (5) and (6), the cross-polarization cancellation matrix D may be rewritten to more precisely define the cross-polarization provided by the cross-polarization cancellation element 34 of FIG. 7 as follows:
D = c [ cos ( γ / 2 ) jφ 1 sin ( γ / 2 ) jφ 1 sin ( γ / 2 ) jφ 2 cos ( γ / 2 ) jφ 2 ] ( 7 )
[0050] As mentioned above, the cross-polarization correction generally varies based upon the scan angle and the frequency of the signals transmitted and/or received by the antenna. In order to determine the appropriate cross-polarization correction, the antenna 32 is typically analyzed at a plurality of scan angles and, if desired, a plurality of frequencies to determine the internal cross-polarization coupling that occurs and is preferably cancelled. In this regard, an antenna permits internal cross-polarization coupling as defined by a polarization coupling matrix C, having components designated c 11 , c 12 , c 21 and c 22 , is shown in FIG. 8 without any cross-polarization cancellation. In instances in which the antenna is configured to transmit signals, the orthogonally polarized inputs T 1 and T 2 are related to the signals that are output by the dual orthogonally polarized radiating elements 1 and 2 as follows:
1 =[T 1 c 11 +T 2 c 12 ] 1
2 =[T 1 c 21 +T 2 c 22 ] 2 (8)
[0051] By providing an input signal at one port of the antenna while terminating or grounding the other port, and by measuring the outputs of the antenna (V 1 , V 2 ) the co- and cross-polarization components may be determined at the peak of the beam transmitted by the antenna 32 . In this regard, the components of the polarization matrix C can be determined as follows:
c 11 =V 1 /T 1 | T 2 =0 c 21 =V 2 /T 2 | T 2 =0
c 21 =V 1 /T 2 | T 1 =0 c 22 =V 2 /T 2 | T 1 =0
[0052] As described above, the cross-polarization cancellation matrix D is simply the inverse of the polarization matrix C. Thus, the coefficients of the cross-polarization cancellation matrix D may be readily determined based upon the polarization matrix coefficients determined in the manner described above. While these coefficients may be separately determined at each scan angle and at each frequency of interest, the coefficients are generally slowly varying and a well-behaved function of scan angle and frequency. As such, the coefficients may be determined at a few angles and frequencies and the coefficients for angles and frequencies other than those at which the coefficients were specifically determined may be calculated by interpolation. In addition, the variation of the coefficients based upon changes in the frequency is typically relatively minor and may therefore be ignored in some embodiments without nullifying the efficacy of the cross-polarization cancellation technique of the present invention at satellite communication bandwidths. The coefficients of the cross-polarization matrix D that is determined as described above may then be stored in a memory device and accessed by a processor, a controller or the like during operation in order to properly adjust the amplitude and shift the phase of the signals applied to or received by the antenna. Accordingly, the internal cross-polarization coupling of the antenna may be effectively cancelled.
[0053] While the foregoing embodiments of the antenna system 30 provide open loop control, the antenna system 58 may instead include closed loop control. In this regard, the antenna system may include both a transmission antenna 60 and a reception antenna 62 , each of which are dual orthogonally polarized antennas. In addition, each antenna permits internal cross-polarization coupling between the orthogonally polarized signals. According to this embodiment of the present invention, the antenna system includes first and second cross-polarization cancellation elements 64 , 66 associated with the reception and transmission antennas, respectively. While various types of cross-polarization cancellation elements may be employed, such as those described above and depicted in FIGS. 5 - 7 , the antenna system of the illustrated embodiment includes first and second cross-polarization cancellation elements as described above in conjunction with FIG. 7. Regardless of the embodiment of the cross-polarization cancellation elements, each cross-polarization cancellation element includes a delta (Δ) port and a sum (Σ) port. With respect to the transmission antenna, the delta port is frequently terminated with a matched load and the signal to be transmitted is generally provided via the sum port. Additionally, the antenna system of this embodiment includes a processor 68 for setting the phase shift imparted by the phase shifter 52 of the first cross-polarization cancellation element and, the amplitude adjustment provided by the adjustable phase shifters 50 of the first cross-polarization cancellation element. As an aside, it is note that the phase shifters 50 combined with two 90° hybrids provide an equivalent variable attenuator or power divider configuration. Preferably, the processor sets the relative phase shift and adjusts the relative amplitude between the reception antenna outputs in an iterative manner until a null is provided at the delta port in response to a signal of given polarization received by the reception antenna and presented at the antenna terminals. While nulling at the delta port, the signal power is simultaneously maximized at the sum port. Looking from the sum port, the network 64 can be seen to compensate for the cross-coupling and any other polarization distorting effects occurring within the reception antenna, Once the appropriate phase shift and amplitude adjustment have been determined, the processor directs the phase shifters 52 and 50 of the second cross-polarization cancellation element to provide the same relative phase shifts and relative amplitude adjustments in the transmit antenna such that the signal radiated by the transmitted antenna has a polarization matched to that incident at the reception antenna. In this regard, it is assumed that the transmit and receive phased array antennas have similar type radiating elements and have similar element lattice and spacing relative to wavelength and that both transmit and receive antennas are pointed at the same source, such as a satellite. By adaptively configuring the first and second cross-polarization correction elements 64 , 66 as described above, the polarization of the signals transmitted by the transmission antenna 60 will be colinear with the field vector incident on the reception antenna 62 . Advantageously, the closed loop technique for configuring the first and second cross-polarization cancellation elements does not require knowledge of the polarization characteristics of the antennas as a function of scan angle or frequency.
[0054] Accordingly, the antenna system and associated method of the present invention provides active correction for internal coupling between the orthogonally polarized signals permitted by the dual orthogonally polarized antenna, such as a phased array antennas. As such, the antenna can transmit and/or receive dual orthogonally polarized signals across a full range of scan angles without concern as to the degradation of the polarization purity of the signals. Additionally, the antenna system of the present invention provides active polarization correction without substantially increasing the cost of the antenna system and without significantly impacting the size or packaging requirements of the antenna.
[0055] Many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | An antenna system and an associated method are provided that are capable of providing improved cross-polarization isolation, thereby negating the otherwise deleterious effects of cross-coupling between orthogonally polarized signals that occur within a dual orthogonally polarized antenna, such as a phased array antenna. Thus, the antenna system can more reliably transmit and/or receive dual orthogonally polarized signals over a wide range of elevation and azimuth scan angles. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electronic sphygmomanometer, and, in particular, to a constant rate air-bleed adjustment device for a sphygmomanometer whereby the pressure in a cuff can be easily adjusted to drop at a substantially uniform rate.
2. Description of the Prior Art
Conventional electronic sphygmomanometers wherein a cuff is pressurized by means of a battery-driven electric pump, a pulse and the air pressure inside the cuff are detected by a pressure sensor, and the systolic and diastolic blood pressure values of a patient whose blood pressure is being measured are obtained and displayed on a digital display device are in widespread use.
In this type of electronic sphygmomanometer, a constant rate air-bleed device is used in order to reduce the pressure of the air inside the cuff at a constant rate.
FIG. 1 shows one example of a constant rate air-bleed valve used with a conventional electronic sphygmomanometer.
In this constant rate air-bleed valve, a flange section 2a of a tubular member 2, as shown in FIG. 2, is insertedly pressed into an inner section of an air-bleed valve casing 1 with a pressure side part la by means of a nut 3, and, in addition, a regulating member 4 is screwed into the nut 3 (as, for example, in Japanese Patent Publication 63-14809).
The flange section 2a is provided on one end of the tubular member 2, as shown in FIG. 2, and on the outer peripheral side surface of the tubular member 2, a slit 2b is provided, extending in the longitudinal direction from the flange section 2a. An air-bleed hole 4a is formed in the center of the regulating member 4, and an end 4b of the regulating member 4 contacts the flange section 2a of the tubular member 2. The rate of pressure reduction is regulated by screwing in the regulating member 4, thus increasing the pressure on the the tubular member 2 in the thrust direction, so that the amount of open area of the longitudinal slit 2b increases, corresponding to this pressure.
Accordingly, in this type of conventional constant-rate air-bleed valve, because the longitudinal slit 2a is provided in the tubular member 2, a uniform length in the longitudinal direction is absolutely necessary to obtain good characteristics. In addition, because pressure must be added in the thrust direction, the length of the regulating section in the longitudinal direction must be great. Also, to ensure that the regulating section is airtight, the regulating section must also be large in the radial direction. This gives rise to the drawback that the overall air-bleed valve must be large.
SUMMARY OF THE INVENTION
An object of the present invention is to provide, with due consideration to the drawbacks of such conventional devices, a small-sized, high-performance electronic sphygmomanometer wherein the rate of drop of the air pressure can be easily adjusted as a result of improvements to the air bleed valve so that blood pressure can be precisely measured with a minimum of error.
The object of the present invention is achieved by the provision of an electronic sphygmomanometer with a configuration wherein, in the air piping system, an open end of a tubular member, which is the main body of an air-bleed valve, is positioned on the low pressure side; the other end, which is a closed end, is positioned on the high pressure side, specifically, the airflow intake end during air bleed; and this other end is provided with a radial slit at the closed end of the tubular member which is formed from an elastic member; and the slit is caused to open by an adjustment member which applies pressure to the cylindrical surface of the tubular member.
In this configuration, when the pressure in the cuff is high during the measurement of the blood pressure, the slit opening in the tubular member remains narrow because of the backpressure applied by the adjustment member. When the pressure in the cuff drops, the opening widens in proportion to this drop because the cylindrical member returns to its original shape. Specifically, it is possible to maintain a constant rate of pressure drop by a minute change in the area of the opening in the slit. In addition, the shape of the tubular member and its hardness and elasticity are determined during the design process so that the rate of pressure drop can be controlled by setting the amount of opening in the slit with the adjustment member.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
These and other objects, features, and advantages of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a sectional view of a constant rate air-bleed valve used with a conventional electronic sphygmomanometer.
FIG. 2 is a perspective view of a tubular member incorporating the constant rate airbleed valve shown in FIG. 1.
FIG. 3 is a perspective view showing the conditions of use of the electronic sphygmomanometer of the present invention.
FIG. 4 is a perspective view showing the electronic sphygmomanometer of the present invention with the upper casing removed.
FIG. 5 is an end elevation of a pressure pump for the electronic sphygmomanometer of the present invention.
FIG. 6 is a sectional view of one embodiment of the constant rate air-bleed valve used with the electronic sphygmomanometer of the present invention.
FIG. 7 is a perspective view of a tubular member incorporating the constant rate air-bleed valve shown in FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will now be explained with reference to the drawings.
FIG. 3 shows the conditions of use of the electronic sphygmomanometer of the present invention.
An electronic sphygmomanometer 16 comprises a main body, made up of an upper casing 17 and a lower casing 18, and a cuff 19 to be applied to an arm 21, the main body and the cuff 19 being joined through a rubber tube 20. A liquid crystal display device 33 for displaying the blood pressure of patient being examined and the initially set pressurization value is provided on the surface of the upper casing 17 together with a power switch 22, a measurement switch 23 for starting the measurement, a memory switch 24 for storing the measured blood pressure values in memory, and an initial pressurization value set switch 25 for optionally setting the initial pressurization value at the cuff.
Next, the internal configuration of the electronic sphygmomanometer 16 will be explained based on FIG. 4. FIG. 4 shows the state of the electronic sphygmomanometer 16 with the upper casing 17 and the rubber tube 20 removed. The main components of the internal section of the electronic sphygmomanometer 16 are a pressure pump 2b, a magnetic valve 31, a circuit substrate 32, the liquid crystal display device 33, and a battery housing chamber 34.
The pressure pump 26 as shown in FIG. 5 is a diaphragm compressor which is provided with a diaphragm 27 fabricated from nitrile butadiene rubber (hereinafter NBR). The center section of the diaphragm 27 has a mounting section 27a provided with a shaft 39. In addition, an air intake valve 27b and an air-bleed valve 27c are provided on the outer peripheral section of the diaphragm 27, and the inner peripheral sections of the air intake valve 27b and the air-bleed valve 27c are interposedly secured between an upper pump casing 28 and a lower pump casing 29.
The upper pump casing 28 is provided with an air intake port 28a and an air-bleed port 28b respectively positioned opposite the air intake valve 27b and the air-bleed valve 27c of the diaphragm 27. The upper pump casing 28 is integrally formed with a later-described air-bleed valve casing 5. A chamber 40 is formed between the diaphragm 27 and the lower pump casing 29, and a packing 42 is provided to hermetically seal the upper pump casing 28 and the lower pump casing 29.
A motor 30 is provided to activate the diaphragm 27 in the vertical direction. The shaft 39 provided on the mounting section 27a of the diaphragm 27 is eccentrically mounted on a shaft 30a of the motor 30.
A channel 41 communicates with the air-bleed port 28b and is connected to a pressure side port of a later-described constant rate air bleed valve 27c for the sphygmomanometer.
A rubber tube 36 is provided for introducing the air exiting from the air-bleed port 28b to a pressurizing port 31a of the magnetic valve 31. The rubber tube 20 is connected to the pressurizing port 31a of the magnetic valve 31, and feeds the air into the cuff 19. One end of a rubber tube 37 is connected to the magnetic valve 31 and communicates with the pressurizing port 31a. The other end of the rubber tube 37 is connected to a pressure sensor (omitted from the drawings) mounted on the circuit board 32. The magnetic valve 31 is also provided with an air-bleed port 31b, and when the blood pressure measurement is completed the magnetic valve 31 opens to allow the air in the cuff 19 to bleed out through the air-bleed port 31b.
In addition to the pressure sensor (omitted from the drawings), the power switch 22, the measurement switch 23, the memory switch 24, and the initial pressurization value set switch 25 are positioned on an IC chip 43, together with a necessary wiring system for supplying power and signals to the pressurizing pump 26.
The liquid crystal display device 33, which displays the blood pressure values and the like, is connected to the circuit substrate 32 through a flat cable 38.
The battery housing chamber 34, which is integrally formed with the lower casing 18, houses a battery (omitted from the drawings).
FIG. 6 is a sectional view of one embodiment of the constant rate air-bleed valve used with the electronic sphygmomanometer of the present invention.
A tubular member 10 which is illustrated in FIG. 7 is positioned inside an air-bleed valve casing 5. One end of the tubular member 10 is open, and the other end is formed as an elastic member fabricated from rubber (such as, for example, silicone rubber or NBR, of a spring-type hardness of 60°) and is closed. The tubular member 10 comprises a large diameter section 10a, a medium diameter section 10b, and a small diameter section 10c, the diameters of all these sections being different. A fine slit 11 is formed in the radial direction in the small diameter section 10c of the tubular member 10, which is the same direction as the forward movement of a later-described adjusting member 6. The large diameter section 10a of the tubular member 10 is engaged by a medium diameter diameter section 5a of the air-bleed valve casing 5 while ensuring air tightness.
The air-bleed valve casing 5 is shaped as a hollow tube. A projection 5b for housing a regulating member 6 is provided on the surface of the cylinder. A nut 7 is embeddedly secured in the projection 5b, and the regulating member 6 can be screwed into the nut 7 causing the regulating member 6 to advance. A tip 6a of the regulating member 6 penetrates through a small hole 5c in the side surface of the air-bleed valve casing 5, and the tip 6a is formed so that it presses against an outer peripheral surface 8 of the tubular member 10. When the regulating member 6 is screwed into the nut 7, an opening is formed in the slit 11 proportional to the amount by which the regulating member 6 is screwed in. An O-ring 9 is provided on the head of the regulating member 6 to ensure the airtightness of the regulating member 6. In the air-bleed regulating device of this configuration, the air piping system of the sphygmomanometer has an open end 10a on the low pressure side and a pressure side port 5 d on the high pressure side.
As shown in FIG. 4, the constant rate air-bleed valve is positioned in the lower casing 18 so that the longitudinal direction of the tubular member 10 becomes the lateral direction of the constant rate air-bleed valve, and the projection 5b, which is the regulating part, is positioned facing upward so that regulation from the top is possible.
The operation of the electronic sphygmomanometer of the present invention will now be explained.
To use the electronic sphygmomanometer, the cuff 19 is first wrapped around the upper arm of the patient whose blood pressure is to be measured and the power switch is turned ON.
Next, the initial pressurization value set switch 25 is pressed, and the initial pressurization value is optionally selected. In this embodiment of the present invention, the liquid crystal display device 33 shown in FIG. 3 is set for 160 mm Hg.
The pressurization pump 26 is then started by pressing the measurement switch 23. Specifically, the diaphragm 27 is activated vertically through the rotation of the shaft 30a of the motor 30 so that when the diaphragm 27 moves upward, the air intake valve 27b opens and air is drawn into the chamber 40 through the air intake port 28a, and when the diaphragm 27 moves downward, the air-bleed valve 27c opens and air is discharged from the chamber 40 through the air-bleed port 28b. By the repetition of these operations at high speed, air is supplied to the inside of the cuff 19. The pressure inside the cuff 19 is measured through a pressure sensor (omitted from the drawings) connected via the rubber tube 37. When the pressure reaches the initially set pressurization value of 160 mm Hg the rotation of the motor 30 is halted.
Next, the air in the cuff 19 passes through the rubber tubes 20, 36, the air-bleed port 28b of the pressurizing pump 26, and the channel 41, and, as shown in FIG. 6, is fed to the pressure side port 5d provided on the air-bleed pump casing 5 of the constant rate air-bleed valve. The air is then eliminated through the slit 11 in the tubular member 10. A normal air-bleed rate of 3 to 4 mm Hg/sec is desired.
At the same time, the air pressure in the cuff 19 is transmitted to the pressure sensor (omitted from the drawings) through the rubber tube 37 so that the air pressure and the body pulse are detected by the pressure sensor. The systolic and diastolic blood pressure values of the patient whose blood pressure is being measured are calculated and displayed on the liquid crystal display device 33.
When the measurement is completed, the magnetic valve 31 opens and the air in the cuff 19 is rapidly discharged from the air-bleed port 31b.
The measured blood pressure values can be recorded by pressing the memory switch 24.
Because the slit in the constant rate air-bleed valve of the electronic sphygmomanometer of the present invention is provided in the radial direction, it is possible to reduce the longitudinal dimension of the valve, making it possible to provide a constant rate air-bleed valve of reduced overall size. Furthermore, the rate of pressure drop required for the blood pressure measurement can easily be set by means of the regulating member, and once the rate of pressure drop is set, because of the configuration, when the air-bleed pressure is high, the slit is opened a small amount and the air-bleed rate is high, and when the air-bleed pressure is low, the slit is opened a large amount and the air-bleed rate is low. Therefore an almost constant rate can be maintained. Accordingly, the necessary 2 to 4 mm Hg/sec pressure drop rate for the blood pressure measurement from the systolic to the diastolic blood pressure can be easily obtained so that the blood pressure can be effectively and accurately measured.
In the embodiment as above described, the tubular member is positioned so that the longitudinal direction of the tubular member is the lateral direction of the constant rate air-bleed valve, and the regulating member can be operated on the upper side of the constant rate air-bleed valve. It is therefore possible for a user of the sphygmomanometer to control pressure from above, even if components such as a magnetic valve and circuit board are arranged in close proximity to one another. | A sphygmomanometer including a constant rate air-bleed valve for that is coupled to a cuff for reducing the pressure in the cuff. The valve has a valve casing and a tubular member in the casing. A slit in the tubular member allows air to bleed from the cuff at the constant rate and a regulator is provided for adjusting the bleed rate. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to radiation-hardened circuits, and more particularly to a radiation-hardened latch circuit for reducing the propagation of pulses and other effects caused by single event transients.
[0003] 2. Discussion of the Related Art
[0004] Single event transients (“SET”) can cause voltage glitches and pulses to be generated within an integrated circuit, thus causing disruption and degradation of performance by, for example, undesired switching of circuit blocks. These pulses and glitches can further propagate throughout the integrated circuit causing even further disruption and degradation of performance.
[0005] What is desired, therefore, is a method and circuit that is itself radiation-hardened and will eliminate or at least substantially reduce the propagation of voltage pulses or glitches throughout the integrated circuit caused by the SET event.
BRIEF SUMMARY OF THE INVENTION
[0006] According to a first embodiment of the present invention, a radiation hardened latch circuit comprises a first latch stage having a first input for receiving a data signal, a second input for receiving a clock signal, and an output, and a second latch stage having a first input coupled to the output of the first latch stage, a second input for receiving an inverted clock signal, and an output for providing an output signal. The first latch stage comprises a first N-channel cascode stage coupled to the first input thereof, a second N-channel cascode stage coupled to the second input thereof, and a cross-coupled P-channel cascode stage coupled to the output thereof. The second latch stage comprises a first N-channel cascode stage coupled to the first input thereof, a second N-channel cascode stage coupled to the second input thereof, and a cross-coupled P-channel cascode stage coupled to the output thereof. The first and second inputs of the first and second latch stages comprise differential inputs.
[0007] According to a second embodiment of the present invention, a radiation hardened latch circuit comprises a first latch stage having a first input for receiving a data signal, a second input for receiving a clock signal and an output, a second latch stage having an input-coupled to the output of the first latch stage and an output, a third latch stage having a first input coupled to the output of the second latch stage, a second input for receiving an inverted clock signal and an output, and a fourth latch stage having an input coupled to the output of the third latch stage and an output for providing an output signal. The first and third latch stages each comprise a first N-channel cascode stage coupled to the first input thereof, a second N-channel cascode stage coupled to the second input thereof, and a cross-coupled P-channel cascode stage coupled to the output thereof. The second and fourth latch stages each comprise an N-channel cascode stage coupled to the input thereof, and a cross-coupled P-channel cascode stage coupled to the output thereof. The first and second inputs of the first and third latch stages comprise differential inputs.
[0008] According to a third embodiment of the present invention, a radiation hardened signal distribution circuit comprises a plurality of serially coupled latch circuits having an input for receiving an input signal, an output for providing an output signal, and an intermediate node for providing a tap signal. Each latch circuit comprises two or four latch stages, and the input signal can comprise a clock signal.
[0009] According to a fourth embodiment of the present invention, a radiation hardened integrated circuit comprises a plurality of integrated circuit portions each for providing a standalone circuit function, and a plurality of latch circuits not associated with the standalone circuit function for interconnecting the plurality of circuit portions. The latch circuit can comprise a single latch circuit, or two serially-coupled latch circuits. In turn, the latch circuits can comprise two or four latch stages.
[0010] According to a method of the present invention, radiation hardening an integrated circuit comprises providing a plurality of standalone circuit functions with a plurality of integrated circuit portions, and interconnecting the plurality of integrated circuit portions with a plurality of latch circuits not associated with the standalone circuit function. The latch circuits can comprise two or four latch stages.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0011] The invention, together with its various features and advantages and other aspects, can be readily understood from the following more detailed description taken in conjunction with the accompanying drawing figures, in which:
[0012] FIG. 1 is a schematic of a first RS latch circuit according to the prior art;
[0013] FIG. 2 is a schematic of a second RS latch circuit according to the prior art;
[0014] FIG. 3A is a schematic of a first test circuit according to the present invention;
[0015] FIG. 3B is a schematic of a second test circuit according to the present invention;
[0016] FIG. 4 is a schematic of a first latch circuit having two latch stages according to the present invention;
[0017] FIG. 5 is a schematic of a second latch circuit having four latch stages according to the present invention;
[0018] FIG. 6A is a schematic of a clock distribution circuit according to the prior art;
[0019] FIG. 6B is a schematic of a clock distribution circuit according to the present invention;
[0020] FIG. 7 is a block diagram of a first circuit partitioning for reducing SET glitches in an integrated circuit according to the present invention; and
[0021] FIG. 8 is a block diagram of a second circuit partitioning for reducing SET glitches in an integrated circuit according to the present invention.
DETAILED DESCRIPTION
[0022] Referring now to FIG. 1 , an RS latch 100 according to the prior art is shown. A P-channel transistor T 0 has a source coupled to VDD, a gate coupled to an RB input, and a drain coupled to a QB output. A P-channel transistor T 1 has a source coupled to VDD, a gate coupled to an SB input, and a drain coupled to a Q output. Transistors T 2 and T 3 form a cross-coupled pair. The N-channel transistor T 2 has a source coupled to VSS, a gate coupled to the Q output, and a drain coupled to the QB output. The N-channel transistor T 3 has a source coupled to VSS, a gate coupled to the QB output, and a drain coupled to the Q output.
[0023] The logic state diagram for RS latch 100 is given below:
[0000]
Mode
RB
SB
Q N+1
QB N+1
N/A
0
0
1
1
NORMAL
0
1
1
0
NORMAL
1
0
0
1
NOOP
1
1
Q N
QB N
[0024] It was observed by the inventor that the NOOP mode of operation wherein the RB and SB inputs are both high and the N/A mode of operation wherein the RB and SB inputs are both low could be used to stop the propagation of an errant input signal caused by an SET event. Errant pulses or glitches on the RB and SB inputs do not propagate past the output of the RS latch.
[0025] Referring now to FIG. 2 , an RS latch 200 according to the prior art is shown. Transistors T 0 and T 1 form a cross-coupled pair. The P-channel transistor T 0 has a source coupled to VDD, a gate coupled to a Q output, and a drain coupled to a QB output. The P-channel transistor T 1 has a source coupled to VDD, a gate coupled to the QB output, and a drain coupled to the Q output. An N-channel transistor T 2 has a source coupled to VSS, a gate coupled to an S input, and a drain coupled to the QB output. An N-channel transistor T 3 has a source coupled to VSS, a gate coupled to an R input, and a drain coupled to the Q output.
[0026] The logic state diagram for RS latch 200 is given below:
[0000]
Mode
R
S
Q N+1
QB N+1
NOOP
0
0
Q N
QB N
NORMAL
0
1
1
0
NORMAL
1
0
0
1
N/A
1
1
0
0
[0027] It was similarly observed by the inventor that the N/A mode of operation wherein the R and S inputs are both high and the NOOP mode of operation wherein the R and S inputs are both low could be used to stop the propagation of an errant input signal caused by an SET event. Errant pulses or glitches on the R and S inputs do not propagate past the output of the RS latch.
[0028] According to the present invention, a first test circuit 300 A is shown in FIG. 3A for measuring the error rate for injected pulses. Test circuit 300 includes a first RS latch 302 , a last RS latch 304 , and plurality of serially coupled circuits under test (CUT) CUT 1 , CUT 2 , CUT 3 , and CUT 4 . While two RS latches and four CUTs are shown in test circuit 300 , any number of CUTs could be used. The Q output of latch 302 is coupled to the inputs of CUT 1 . The output of a CUT (CUT 1 , for example) is coupled to the input of the next CUT in the chain (CUT 2 , for example). A first latch 302 has an RB input coupled to the Resetb input of the test circuit, and an SB input coupled to the Setb input of the test circuit. A last latch 304 has an RB input coupled to the output of CUT 4 , an SB input coupled to the Setb input of the test circuit, a Q output coupled to the Err output of the test circuit, and a QB output coupled to the Errb output of the test circuit. In operation, the test circuit 300 A is used to test the SET sensitivity of various circuits.
[0029] According to the present invention, a second test circuit 300 B is shown in FIG. 3B for measuring the error rate for injected pulses. Test circuit 300 B includes a plurality of serially coupled RS latches I 0 , I 1 , I 2 , I 3 , I 4 , and I 5 . While six RS latches are shown in test circuit 300 B, any number of latches could be used. The Q and QB outputs of each latch are coupled to the S and R inputs of the next latch in the chain. A first latch I 0 has an RB input coupled to the Resetb input of the test circuit, and an SB input coupled to the Setb input of the test circuit. A last latch I 5 has an RB input coupled to the Q output of latch I 4 , an SB input coupled to the Setb input of the test circuit, a Q output coupled to the Err output of the test circuit, and a QB output coupled to the Errb output of the test circuit. A SET pulse injection point for positive going pulses is at the R input of latch I 2 . A SET pulse injection point for negative going pulses is at the S input of latch I 3 . In operation, the test circuit 300 B is also used to test the SET sensitivity of various circuits.
[0030] While an ordinary prior art RS latch could be used for the purpose of stopping glitches from propagating throughout an integrated circuit, the RS latch itself should be radiation hardened. That is to say, the RS latch of the prior art will be ineffective for stopping glitch propagation if it is directly hit by an SET event.
[0031] According to an embodiment of the present invention, a radiation hardened latch circuit 400 is shown in FIG. 4 wherein a first latch stage T 0 , T 1 , T 2 , T 3 , T 4 , T 5 , has a first input for receiving a D data signal directly and through inverter T 22 , T 23 , a second input for receiving a CLK clock signal, and an output N 1 , N 2 . A second latch stage T 12 , T 13 , T 14 , T 15 , T 18 , T 19 has a first input coupled to the output of the first latch stage, a second input for receiving an inverted clock signal through inverter T 20 , T 21 , and an output for providing an output signal Q, QB. The first latch stage comprises a first N-channel cascode stage T 4 , T 5 coupled to the first input thereof, a second N-channel cascode stage coupled to the second input thereof T 2 , T 3 , and a cross-coupled P-channel cascode stage T 0 , T 1 coupled to the output thereof. The second latch stage comprises a first N-channel cascode stage T 12 , T 13 coupled to the first input thereof, a second N-channel cascode stage T 14 , T 15 coupled to the second input thereof, and a cross-coupled P-channel cascode stage T 18 , T 19 coupled to the output thereof. As can be seen in FIG. 4 , the first and second inputs of the first and second latch stages comprise differential inputs. The outputs of the first and second latch stages are also differential outputs.
[0032] According to an embodiment of the present invention, a radiation hardened latch circuit 500 is shown in FIG. 5 wherein a first latch stage T 0 , T 1 , T 2 , T 3 , T 4 , and T 5 has a first input for receiving a data signal directly and through inverter T 22 , T 23 , a second input for receiving a CLK clock signal, and an output N 1 , N 2 . A second latch stage T 6 , T 7 , T 8 , T 9 has an input coupled to the output of the first latch stage, and an output N 3 , N 4 . A third latch stage T 12 , T 13 , T 14 , T 15 , T 18 , T 19 has a first input coupled to the output of the second latch stage, a second input for receiving an inverted clock signal through inverter T 20 , T 21 , and an output N 5 , N 6 . A fourth latch stage T 10 , T 11 , T 16 , T 17 has an input coupled to the output of the third latch stage, and an output Q, QB for providing an output signal. The first and third latch stages each comprise a first N-channel cascode stage coupled to the first input thereof, a second N-channel cascode stage coupled to the second input thereof, and a cross-coupled P-channel cascode stage coupled to the output thereof. The second and fourth latch stages each comprise an N-channel cascode stage coupled to the input thereof, and a cross-coupled P-channel cascode stage coupled to the output thereof. The first and second inputs of the first and third latch stages comprise differential inputs. The first and third latch stages also comprise differential outputs. The second and fourth latch stages have differential inputs and outputs.
[0033] Referring now to FIG. 6A , a prior art clock distribution circuit 602 is shown including a plurality of inverters I 1 through 14 . Any number of inverters can be used as is known in the art. A first inverter I 1 receives a CLK IN input signal, and a last inverter I 4 provides a CLK OUT output signal. Intermediate tap nodes TAP 1 , TAP 2 , and TAP 3 provide the clock signal or inverted clock signals as is known in the art. The clock distribution circuit 602 is adequate for providing a plurality of clock signals throughout an integrated circuit. However, once generated SET induced glitches will propagate from the generation point throughout the entire circuit.
[0034] Referring now to FIG. 6B a radiation hardened signal distribution circuit 604 according to the present invention comprises a plurality of serially coupled latch circuits RS 1 , RS 2 , RS 3 , and RS 4 . A first latch RS 1 has an input for receiving an input signal CLK IN and CLKB IN. A last latch RS 4 has an output for providing an output signal CLK OUT and CLKB OUT. A plurality of intermediate nodes provide clock and inverted clock tap signals TAP 1 A, TAP 1 B, TAP 2 A, TAP 2 B, TAP 3 A, and TAP 3 B. While requiring additional circuitry, the clock distribution circuit of FIG. 6B has the advantage that any SET induced glitches are stopped at least at the next latch stage and do not propagate further through the latch chain. Each latch circuit can comprise one or more latch stages as simple as shown in FIG. 1 or FIG. 2 or more complex latches as shown in FIG. 4 or FIG. 5 . Each latch circuit can comprise two latch stages as was shown with respect to latch circuit 400 shown in FIG. 4 for additional radiation hardening. Each latch stage can also comprise four latch stages as was shown with respect to latch circuit 500 shown in FIG. 5 for still further additional radiation hardening. While an input clock signal is shown in FIG. 6B other types of input signals can of course be distributed as desired.
[0035] Referring now to FIG. 7 , a radiation hardened integrated circuit 700 comprises a plurality of integrated circuit portions CKT # 1 , CKT # 2 , CKT # 3 , each for providing a standalone circuit function. A plurality of single latch circuits RS 1 , RS 2 not associated with the standalone circuit function are provided for interconnecting the plurality of circuit portions. The additional single latch circuits RS 1 , RS 2 are used solely for stopping the propagation of SET induced glitches as previously discussed. Each one of the single latch circuits can include two or four latch stages for additional radiation hardening as previously discussed.
[0036] Referring now to FIG. 8 , a radiation hardened integrated circuit 800 comprises a plurality of integrated circuit portions CKT # 1 , CKT # 2 , CKT # 3 , each for providing a standalone circuit function. A plurality of two serially-coupled latch circuits RS 1 , RS 2 and RS 3 , RS 4 not associated with the standalone circuit function are provided for interconnecting the plurality of circuit portions. The additional latch circuits RS 1 , RS 2 and RS 3 , RS 4 are used solely for stopping the propagation of SET induced glitches as previously discussed. Each one of the latch circuits can include two or four latch stages for additional radiation hardening as previously discussed.
[0037] A method of radiation hardening an integrated circuit has been shown comprising providing a plurality of standalone circuit functions with a plurality of integrated circuit portions, and interconnecting the plurality of integrated circuit portions with a plurality of latch circuits not associated with the standalone circuit function.
[0038] It is to be understood that the above-described circuits, embodiments, and drawing figures are merely illustrative of the many possible specific embodiments that can be devised to represent applications of the principles of the present invention. Numerous and varied other arrangements can be devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention. For example, the exact details of the circuit topography, component values, power supply values, as well as other details may be obviously changed to meet the specifications of a particular application. | Circuits and a corresponding method are used to eliminate or greatly reduce SET induced glitch propagation in a radiation hardened integrated circuit. A clock distribution circuit and an integrated circuit portioning can be radiation hardened using one or two latch circuits interspersed through the integrated circuit, each having two or four latch stages. | 7 |
This application is a continuation of now abandoned application Ser. No. 07/810,884, filed Dec. 20, 1991.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a vinyl chloride resin composition for vinyl chloride resin products and also to a matte-finished or surface delustered article produced therefrom.
2. Description of the Prior Art
There is an increasing demand for matte-finished vinyl chloride resin products in such application areas as wall covering, flooring, vehicle interior, electric wires, and daily necessities, where reduced surface gloss, non-glare reflection, dry feeling, and quiet appearance are desirable. There are several methods for their matte finishing by (1) physically forming a rough surface, (2) compounding with a special component which gives rise to a rough surface, or (3) coating the surface with dull lacquer.
Method (1) involves embossing with finely textured dies, sand blasting, and dusting with fine particles in the course of molding. A disadvantage of mechanical embossing is unsatisfactory matte-finishing which results from the fading out of embossed patterns that takes place after the embossing operation owing to the viscoelastic properties of the material. Another disadvantage of mechanical embossing is that the embossing die becomes contaminated during the embossing operation. Sand blasting is applicable only to articles having a hard surface and needs a complex apparatus to confine and recover fine particles. Dusting with fine particles also needs a special apparatus for uniform dusting and recovery of fine particles.
Method (2) involves blending with a vinyl chloride resin having a different particle diameter, blending with a vinyl chloride resin having a different degree of polymerization, incorporation with a specific polymer other than vinyl chloride resin, partial crosslinking, and incorporation of a large amount of inorganic filler such as calcium carbonate. The first three methods have a disadvantage that the molding process depends largely on the molding condition, that is, no satisfactory matting effect is obtained with a high molding temperature. Incorporation with a large amount of filler has an adverse effect on the physical properties of articles, e.g., decrease in tensile strength.
Method (3) is effective in matte finishing but is economically poor in that it needs a special coating material and additional steps for coating and drying.
The present invention was completed to address the above-mentioned problems associated with the conventional matte-finishing method for vinyl chloride resin products.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a vinyl chloride resin composition which yields molded articles having a good matte-finish surface because of its ability to form minute irregularities uniformly when it is molded by means of the existing apparatus for the casting, dipping, or coating of plastisol or organosol.
The present invention is embodied in a vinyl chloride resin composition incorporated with 0.002-0.02 mol of zinc carboxylate for 100 g of vinyl chloride resin and 0.3-5 mol of a compound having two or more alcoholic hydroxyl groups in one molecule per mol of said zinc carboxylate.
The vinyl chloride resin composition of the above-mentioned special composition yields molded articles having a good matte-finishing surface with minute corrugations.
DETAILED DESCRIPTION OF THE INVENTION
The vinyl chloride resin composition of the present invention is based on a vinyl chloride resin which is a homopolymer of vinyl chloride, or a copolymer of vinyl chloride with a comonomer copolymerizable with vinyl chloride, or a mixture thereof. Exemplary comonomers include vinyl acetate, acrylate esters, and methacrylate esters.
The vinyl chloride resin used in the present invention is usually produced by emulsion polymerization, microsuspension polymerization, suspension polymerization, or bulk polymerization. It is not specifically limited in particle diameter. Its average diameter usually ranges from 0.1 to 200 μm. One having an average diameter of 0.1-80 μm is preferable, which is used in the form of plastisol or organosol.
The zinc carboxylate used in the present invention should preferably be a zinc salt of a monocarboxylic acid having 3-18 carbon atoms. One or more zinc carboxylates may be used. Examples include zinc octanoate, zinc hexanoate, zinc butanoate, zinc propionate, zinc heptanoate, zinc pentanoate, zinc nonanoate, zinc decanoate, zinc 2-ethylhexanoate, zinc laurate, zinc palmitate, and zinc stearate. A zinc salt of a monocarboxylic acid having 6-10 carbon atoms is preferable because it is liquid at normal temperature or readily soluble in common hydrocarbon or carbitol solvents, which facilitates uniform dispersion into the vinyl chloride resin, reducing the amount required for the desired effect.
According to the present invention, the zinc carboxylate should be incorporated in an amount of 0.002-0.02 mol, preferably 0.0025-0.02 mol, for 100 g of the vinyl chloride resin. With an amount less than 0.002 mol, the zinc carboxylate does not produce a satisfactory matte-finishing effect. The zinc carboxylate in excess of 0.02 mol does not add to the matte-finishing effect but is wasted.
Zinc carboxylate is often used, as a heat stabilizer for vinyl chloride resin, in combination with an alkaline earth metal salt of a carboxylic acid, such as calcium carboxylate and barium carboxylate. The latter, however, is detrimental to the matte-finishing effect which is intended in the present invention. Therefore, it should be used in an amount less than 0.7 mol, preferably less than 0.5 mol, per mol of zinc carboxylate.
Other compounds which are detrimental to the matte-finishing effect, like an alkaline earth metal salt of a carboxylic acid, include tin compounds (such as dibutyltin dilaurate and dibutyltin maleate) and lead compounds (such as lead sulfate, lead phosphite, and lead stearate), which are common heat stabilizers for vinyl chloride resin. These tin compounds or lead compounds should be used in an amount less than 0.3 mol per mol of zinc carboxylate, if they are to be used in combination with a zinc carboxylate. Additional compounds detrimental to the matte-finishing effect include alkali metal carboxylates, which should be used in an amount less than 0.3 mol per mol of zinc carboxylate.
The vinyl chloride resin composition of the present invention is incorporated with a compound having two or more alcoholic hydroxyl groups in one molecule (referred to as polyhydric alcohol). Examples of the polyhydric alcohol include glycerin, pentaerythritol, dipentaerythritol, sorbitol, 1,4-sorbitan, 1,5-sorbitan, and mannitol. They also include partial esters formed from the polyhydric alcohol and a fatty acid having 12-18 carbon atoms, which are exemplified by sorbitan partial esters (such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monooleate, sorbitan monostearate sorbitan and distearate), glycerin partial esters (such as glycerin monolaurate and glycerin monooleate), condensed glycerin partial esters (such as diglycerin monolaurate, tetraglycerin oleate, hexaglycerin laurate, and decaglycerin laurate), partial esters of a fatty acid with pentaerythritol monostearate), trimethylolpropane monoesters (such as trimethylolpropane monostearate), and partial esters of glycerin with a hydroxycarboxylic acid (such as glycerin monohydroxystearate).
According to the present invention, the polyhydric alcohol should be used in an amount of 0.3-5 mol, preferably 0.5-4.5 mol, per mol of the above-mentioned zinc carboxylate. (The molar amount is based on a polyhydric alcohol having three hydroxyl groups in one molecule.) With an amount less than 0.3 mol, the polyhydric alcohol does not produce the desired matte-finishing effect. With an amount in excess of 5 mol, the polyhydric alcohol bleeds out of the molded article, resulting in coarse surface irregularities which are detrimental to the uniform matte-finishing effect. Moreover, an excess amount of polyhydric alcohol leads to a higher production cost. In the case of a polyhydric alcohol having any number of hydroxyl groups except three, the amount should be corrected by multiplying the above-mentioned standard amount (0.3-5 mol) by a factor which is calculated by dividing 3 by the number of hydroxyl groups in one molecule. In the case of a partial ester of a fatty acid with a polyhydric alcohol or a mixture of partial esters, where the number of hydroxyl groups in one molecule is not definite, an adequate amount should be established by trial and error on the basis of the above-mentioned amount.
The vinyl chloride resin composition of the present invention may be incorporated with a variety of additives, such as plasticizer, filler, pigment, stabilizer, and blending resin, which are commonly used for vinyl chloride resins. However, some stabilizers could be detrimental to the matte-finishing effect, as mentioned above.
For example the vinyl chloride resin composition of the present invention is in the form of plastisol or organosol which is composed of a vinyl chloride resin and a variety of components. It is processed into film, sheet, leather, and other molded articles by casting, dipping, or coating. The molded articles are finished by heat treatment for gelation. The heat treatment may be accomplished by means of an oven or drying tunnel. This step is important for the matte-finishing effect to fully develop.
The matte-finishing effect depends on the heating temperature and heating time. In the case of a small oven, heating should be carried out at 200° C. for more than about 40 seconds, at 180° C. for more than about 80 seconds, at 160° C. for more than about 120 seconds, or at 140° C. for more than 160 seconds. An adequate heating condition should be selected according to the particular composition.
The vinyl chloride resin composition of the present invention is not specifically limited in its form and molding method. It may take a powder form and pellet form, in addition to plastisol and organosol. The powder or pellet form may be prepared from an extrusion-grade vinyl chloride resin having an average particle diameter of 100-150 μm. Such a composition may undergo calendaring, extrusion molding, or injection molding. The resulting molded article will have the matte-finishing surface upon post-heating. For example, a rolled sheet may be heated, with its surface kept at about 200° C. for more than 40 seconds, to produce the matte-finishing effect. A composition incorporated with a blowing agent is also capable of matte finishing in a similar manner. Moreover, a powder composition for fluidized bed coating, electrostatic coating, or cast-sintering is capable of matte finishing.
There are no specific restrictions on the method for preparing the vinyl chloride resin composition of the present invention, so long as the resulting composition achieves the desired object of the present invention. For example, it is possible to previously add either a polyhydric alcohol or a zinc carboxylate during the production of vinyl chloride resin.
The vinyl chloride resin composition of the present invention yields molded articles which exhibit a good matte finish effect upon heat treatment after the molding operation. The thus obtained molded articles have a matte-finished surface with reduced gloss, good feel, and non-glaring quiet appearance. The vinyl chloride resin compound of the present invention may be applied to wall covering, flooring, leather, sailcloth, vehicle interior, coated steel sheet, coated cotton cloth, coated yarn, tool gripping coat, protective gloves, toys, and daily necessities.
The invention will be described in more detail with reference to the following examples.
EXAMPLES 1 TO 9 AND COMPARATIVE EXAMPLES 1 TO 3
A plastisol was prepared from the following components by compounding for 15 minutes using a twin-screw stirring mixer.
______________________________________Vinyl chloride resin* 100 g*Sumilit ® PXNHA (a product of SumitomoChemical Co., Ltd.) having an average particlediameter of 1.1 μm.Di-2-ethylhexyl phthalate 65 gCalcium carbonate* 40 g*Whiton ® SB red (a product of Shiraishi Kogyo Co.,Ltd.)Titanium white* 5 g*R-820 (a product of Titan Kogyo Co., Ltd.)Zinc octoate* as per*KV-75A-1, 59% solution (a product of Kyodo Yakuhin TableCo., Ltd.) 1Sorbitan monolaurate as per Table 1______________________________________
The resulting plastisol was cast onto flame-retardant paper to form a 200-μm thick coating using a laboratory knife coater. The coated paper was passed through a tunnel dryer for slight heat treatment so that the coating film was semi-geled. After cooling, rectangular test pieces were cut out of the coated paper. The test pieces were geled completely by heating in an oven at 210° C. for different periods of time as indicated in Table 1. Finally, the test pieces were evaluated by testing for 60° reflectance (%). The smaller the value of 60° reflectance, the better the matte-finishing effect. The 60° reflectance for practical use should be lower than 30%, preferably lower than 10%.
EXAMPLES 10 TO 16 AND COMPARATIVE EXAMPLES 4 AND 5
The same procedure as in Example 7 was repeated except that the sorbitan monolaurate was replaced by the polyhydric alcohol shown in Table 2. The results are also shown in Table 2.
EXAMPLES 17 TO 20 AND COMPARATIVE EXAMPLES 6 TO 8
The same procedure as in Example 6 was repeated except that the zinc octoate was replaced by the zinc carboxylate shown in Table 3. The results are also shown in Table 3.
Incidentally, the specimen in Comparative Example 6 gives low reflectance values, but it is not of practical use because of its coarse surface irregularities.
EXAMPLES 21 TO 26 AND COMPARATIVE EXAMPLES 9 TO 12
The same procedure as in Example 5 was repeated except that the composition was incorporated with any of tin stabilizer ("KS-22" made by Kyodo Yakuhin Co., Ltd.), calcium octoate, and potassium octoate as shown in Table 4. The results are also shown in Table 4.
TABLE 1__________________________________________________________________________(Examples 1 to 9 and Comparative Examples 1 to 3)Example (Comparative Example) 1 2 3 4 5 6 7 8 9 (1) (2) (3)__________________________________________________________________________Zinc octoate addedGrams 1.5 2 2 3 3 3 5 8 11 1.5 1.5 1.0Mol (×10.sup.-3) 2.5 3.4 3.4 5.0 5.0 5.0 8.4 13.5 18.5 2.5 2.5 1.7Sorbitan monolaurate addedGrams 1 1 3 1 3 5 5 11 8 0.2 5 2Mol (×10.sup.-3) 2.9 2.9 8.7 2.9 8.7 14.5 14.5 31.8 23.1 0.6 14.5 5.860° reflectance (%)Geled by heating for 40 s. 70 67 34 57 11 8 2 4 48 65 56 63Geled by heating for 80 s. 8 6 6 3 3 4 2 2 3 61 58 57Geled by heating for 120 s. 4 3 4 2 3 4 2 2 2 58 52 55__________________________________________________________________________
TABLE 2__________________________________________________________________________(Examples 10 to 16 and Comparative Examples 4 and 5)Example (Comparative Example) grams ×10.sup.-3 mol 10 11 12 13 14 15 16 (4) (5)__________________________________________________________________________AdditivesZinc octoate 5 8.4 * * * * * * * * *Sorbitan monopalmitate 5 12.4 *Sorbitan monostearate 5 11.6 *Sorbitan distearate 5 11.3 *Sorbitan monooleate 8 18.6 *Glycerin monolaurate 5 18.2 *Diglycerin monolaurate 5 14.3 *Pentaerythritol 2 14.7 *Sorbitan trioleate 10 10.5 *Glycerin ditrioleate** 8 9.8 *60° reflectance (%)Geled by heating for 40 s. 4 8 8 77 17 17 14 63 61Geled by heating for 80 s. 2 3 4 17 13 16 10 61 58Geled by heating for 120 s. 2 2 3 3 21 17 13 62 62__________________________________________________________________________ *Refer to the left columns for the kind and amount of the additive added. **Rikemal OL95" made by Riken Vitamin Co., Ltd.
TABLE 3__________________________________________________________________________(Examples 17 to 20 and Comparative Examples 6 to 8)Example (Comparative Example) grams ×10.sup.-3 mol 17 18 19 20 (6) (7) (8)__________________________________________________________________________AdditivesZinc hexanoate 4 7.6 *Zinc nanoate 4 7.6 *Zinc laurate 5 10.8 *Zinc stearate 5 7.9 *Zinc acetate 4 21.9 *Zinc oxide 0.5 6.2 *Zinc maleate 1 5.6 *Sorbitan monolaurate 5 14.5 * * * * * * *60° reflectance (%)Geled by heating for 40 s. 14 18 28 20 33 64 69Geled by heating for 80 s. 12 8 24 26 15 61 65Geled by heating for 120 s. 9 6 22 23 6 38 64__________________________________________________________________________ *Refer to the left columns for the kind and amount of the additive added.
TABLE 4__________________________________________________________________________(Examples 21 to 26 and Comparative Examples 9 to 12)Example (Comparative Example) 21 22 23 24 25 26 (9) (10) (11) (12)__________________________________________________________________________AdditivesZinc octoate 3 3 3 3 3 3 3 3 3 3 (5) (5) (5) (5) (5) (5) (5) (5) (5) (5)Sorbitan monolaurate 3 3 3 3 3 3 3 3 3 3 (8.7) (8.7) (8.7) (8.7) (8.7) (8.7) (8.7) (8.7) (8.7) (8.7)Tin stabilizer (KS-22) 0.5 1.0 2 3 (0.6) (1.1) (2.2) (3.3)Calcium octoate 0.7 1 2.2 (2.1) (3.1) (6.7)Potassium octoate 0.3 0.5 1 (0.9) (1.5) (3.1)60° reflectance (%)Geled by heating for 40 s. 62 58 15 57 25 48 44 43 55 51Geled by heating for 80 s. 7 31 3 35 18 38 59 44 52 55Geled by heating for 120 s. 3 10 3 4 5 24 57 47 50 59__________________________________________________________________________ Amount added is expressed in grams and ×10.sup.-3 mol (in parenthesis). | A method of making a matted article, as well as the article per se wherein it is derived from molding and heat treating a vinyl chloride resin composition incorporated with 0.002-0.02 mol of zinc carboxylate for 100 g of vinyl chloride resin and 0.3-5 mol of a compound having two or more alcoholic hydroxyl groups in one molecule per mol of the zinc carboxylate. This composition yields an article having a good matte-finished surface owing to minute corrugated irregularities formed on the surface. | 8 |
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. provisional patent application Nos. 60/575,347 and 60/575,348, both of which were filed May 28, 2004.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to high-density electrical interconnections structures and more particularly to such an interconnection structure that may be used in interposer applications and to connect electrical devices to circuit boards.
[0003] Microelectronic devices such as state-of-the-art microprocessors require large numbers of reliable connections in increasingly-small areas. As the number of connections between an electronic device and a substrate to which the device is to be mounted increases, the likelihood that just a single connections will not be made or will fail increases.
[0004] In “wave soldering,” an electronic components is soldered to a substrate by flowing molten solder over a substrate in which electronic components are mounted. A substrate, to which electronic components are to be soldered, is passed over the flowing, molten solder such that exposed metal and fluxed surfaces on the lower surface of the substrate surface wick the molten solder upward from the solder bath. As the substrate with the wicked, molten solder moves away from the molten solder bath, the solder cools and solidifies, establishing an electrical connection between electronic devices and soldered surfaces of the substrate.
[0005] As connection density increases in the electronic arts and lead lengths from electronic devices decreases, the increasing number of connections that must be made make it statistically more likely that even a single connection will not be made or will fail. Even minor irregularities in a substrate's planarity can cause connection problems.
[0006] One problem with prior art soldering techniques arises when the contact surfaces of a substrate and an electronic device are separated from each other by different distances. For example, if one or two contact leads or one or two contact surfaces of a microprocessor are more widely separated from a planar substrate than the other contact leads or contact surfaces, the molten solder might not wick between the substrate and the more-distant contact surfaces of the electronic device. Prior art soldering techniques suffer from an inability to make a connection when the spacing or distance between contact surfaces of two devices or surfaces to be joined, varies by more than a small amount.
[0007] When even a single connection between an electronic device and its supporting substrate is either not made at the time of manufacture, or fails while in use, the cost to identify a failed electrical connection and to repair it can often exceed the cost to manufacture the product in which the electronic device and supporting substrate operates. Improving the manufacturability of electrical connections and improving the reliability of electrical connections after manufacture would be an improvement over the prior art.
[0008] The present invention is directed to a connector structure that is suitable for use in high-density applications, is easy to manufacture and which provides a reliable contact force while avoiding the aforementioned shortcomings.
SUMMARY OF THE INVENTION
[0009] It is a general object of the present invention to provide a connector device that has a plurality of flexible, conductive rings arranged in an array so as to contact conductive pads on a circuit board and contacts or contact pads of an opposing electronic device.
[0010] Microelectronic devices are electrically connected and mounted to a circuit board or other planar surface using small conductive hollow rings between electrical contacts of an electronic device and a circuit board or substrate. Each ring is a band of pliant conductive material that extends around a center point. An axis of rotation extends through each ring. Each ring's axis of rotation is substantially parallel to the other axes or rotation and to the plane of the substrate and the plane of the electronic device.
[0011] Each ring acts as a small, round spring-type of contact which will deform when a force is directed toward the interior of the ring from any direction. When the force is removed, the ring will return to its original shape. The resilient behavior of the rings provide a small, flexible interconnection which can accommodate variations in the planarity of opposing surfaces. Each ring's flexibility also accommodates circuit board or substrate flexing as well as impacts and vibration.
[0012] These and other objects, features and advantages of the present invention will be clearly understood through a consideration of the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In the course of this detailed description, the reference will be frequently made to the attached drawings in which:
[0014] FIG. 1 is a perspective view of a discrete conductive hollow ring constructed in accordance with the principles of the present invention, and which is suitable for connecting an electronic device to a circuit board or other substrate;
[0015] FIG. 1A shows the deformation of the discrete conductive hollow ring of FIG. 1 in response to an externally-applied force;
[0016] FIG. 2 is a side elevation of a microelectronic device and a plurality of conductive hollow mounting rings mounted to a substrate;
[0017] FIG. 3 is a side elevation of a conductive mounting ring filled with a resilient, non-conductive material and the ring being soldered to a substrate;
[0018] FIG. 4 is a side elevation of a substrate and a plurality of conductive hollow mounting rings mounted to an electronic device; and,
[0019] FIG. 5 shows a conductive ring and the space between an electronic device and a substrate filled with non-conductive resilient material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] FIG. 1 is a perspective view of a discrete conductive hollow ring 10 which is constructed in accordance with the principles of the present invention and which may be used for the mounting of an electronic device to a circuit board or other substrate. In the embodiment shown, the conductive hollow ring 10 has a diameter D substantially the same as the length L of the ring 10 , but other configurations may be used .
[0021] The ring is preferably made up of a band of pliant conductive material, such as a copper or gold alloy or a spring steel coated or plated with a good conductor such as copper or gold. Alternate embodiments can include resilient plastics that are either plated or otherwise conductively coated. Regardless of its material, as is true of all rings, the material from which it is made is centered about a point in space 12 through which extends an axis of rotation 14 for the ring 10 . A force, F, exerted on the ring 10 from the exterior, and directed radially inward of the ring, will cause the ring 10 to deflect as shown in FIG. 1A . As is well-known, as the force F increases past the material's elastic limit, the ring will collapse but as long as the applied force F remains below the elastic limit of the ring material, the ring 10 will act as a spring, and return to its original shape when the applied force is removed. The spring-like action of the ring 10 , when used as in array of rings will provide a connection that can accommodate planarity differences between a substrate 8 and an electronic device 6 . It can also provide a connection that can be flexed and which will be more tolerant of impact and vibration. The improved physical robustness is provided by the flexible material from which the ring 10 is made, a portion of which between the substrate 8 and device 4 is not soldered. The rings may be easily by electro forming or electro-discharge machining to maintain the tolerances down to critical sizes and diameters, such as 500 micrometers and the like.
[0022] The ring 10 illustrated is provided with two strips, or bands, of nickel-plating 20 , 22 that run along the side of the ring 10 from one open end to the other. The nickel plating bands 20 and 22 act as and are referred to herein as solder barriers 20 and 22 . As shown, they are substantially opposite to each other on the exterior surface of the ring 10 . They prevent solder from wicking all the way up and around the circumference of the ring, thereby insuring that at least part of flexible ring side wall will not be soldered to the substrate 8 or an opposing surface, but rather will still remain pliant.
[0023] As shown in FIG. 3 , when the ring 10 is attached to a substrate 8 , molten solder will only wick upwardly until it reaches the solder barriers 20 and 22 . Solder that wicks upward along the exterior of the ring 10 will form fillets 24 between the ring's 10 lower curvature ( FIG. 10 ) and the top of the substrate 8 as part of the normal soldering process. The solder barriers 20 and 22 insure that flexible material from which the ring 10 is made will not be completely coated with solder during a soldering process, insuring that the ring 10 will retain flexibility.
[0024] In a preferred embodiment as shown in FIG. 1 , the ring 10 side wall cross-section is substantially planar or rectangular. In an alternate embodiment, the ring side wall cross-section can be circular, oval or other shape although non-rectangular side wall shapes might tend to be more rigid. Inasmuch as a circle and an oval are both special case ellipses, the more general side wall shape is referred to herein as elliptical.
[0025] FIG. 2 is a side elevation of a microelectronic device 4 positioned just above a plurality of conductive hollow mounting rings 10 , the assembly of which comprise a connector 2 for mounting the electronic device 4 to a circuit board or other substantially planar substrate 8 . Each of the rings 10 in FIG. 2 is substantially the same as the ring 10 shown in FIG. 1 albeit in FIG. 2 , the solder barriers 20 and 22 are not visible.
[0026] The mounting rings 10 in FIG. 2 are aligned to that each of their axes 14 are parallel to each other and extending into the plane of the figure. In an alternate embodiment, the rings 10 can have their axes co-linear.
[0027] Inasmuch as the axes 14 extend into the plane of FIG. 2 , the axes 14 of the rings 10 also tend to extend parallel to the plane of the substrate 8 which also extends into the plane of FIG. 2 , as well as the plane of the underside 6 of the device 4 . The side walls of each ring therefore “face” the substrate 8 and the underside 6 of the device 4 . The planes in which the ring 10 open ends lie are substantially orthogonal to the substrate surface 8 and the underside 6 of the electronic device 4 .
[0028] The several discrete conductive hollow rings 10 each provide a redundant signal path along its body between conductive traces on the surface 8 of the substrate and connection points or nodes on the under side 6 of the electronic device 4 . Signals can traverse both sides of the ring to get from circuits on the device 4 to circuits on the substrate 8 below. This dual signal path also assist in reducing the inductance of the system in which such contacts are used. As shown in FIG. 2 , the several conductive rings 10 are initially attached to the substrate 8 and provide a connector for the device 4 .
[0029] FIG. 3 shows an alternate embodiment of a conductive ring 10 wherein the interior 18 of the ring 10 is filled with a resilient, non-conductive material 18 , such as silicone. The aforementioned solder fillets 24 mechanically and electrically attached the ring 10 to the substrate 8 . Filling the interior 18 space with a resilient material increases the strength of the ring 10 but also prevents solder from flowing into the interior space 18 by either wicking or capillary action.
[0030] FIG. 4 shows a connector 2 for mounting an electronic device. In FIG. 4 , the connector 2 is formed using the aforementioned discrete conductive rings 10 , but the connector 2 in FIG. 4 includes a non-conductive under fill material 26 which holds the conductive rings 10 in place with respect to each other. The under fill material 26 can be a non-conductive silicone layer, the thickness of which is less than the outside diameter of the conductive rings 10 . When the electronic device 4 is urged downward, each of the rings will deform slightly. Because they are pliable, with each of them tending to oppose a downward compressive force, each conductive ring 10 will tend to make physical contact with the surface of the substrate 8 below it as well as the surface 6 of the electronic device 4 above it. Each ring will therefore provide a better electrical and physical contact than is otherwise possible with a straight pin used in the prior art.
[0031] FIG. 5 shows a non-conductive, resilient under fill material 26 disposed between the device 4 and a substrate. It also shows the hollow conductive ring 10 filled with the under fill material, adding stiffness to the ring 10 .
[0032] The connector 2 shown in FIG. 4 can be initially attached to the substrate 8 or to the electronic device 4 . It can be wave soldered to either the substrate 8 , the device 4 or both of them simultaneously.
[0033] As shown in FIG. 2 and FIG. 3 , each of the hollow contact rings 10 of the connector 2 shown in FIG. 4 has solder barriers (not shown in FIG. 4 ) which prevent molten solder from wicking all the way around the ring 10 thereby defeating the flexibility provided by the thin metal from which the rings are made.
[0034] The hollow, conductive rings are preferably made from electronically conductive metals that will also accept a solder barrier. Copper, silver and gold are excellent conductors and can be alloyed with other metals that can provide good resilience; they can also be locally plated with solder-barrier metals such as nickel. The rings 10 can also be formed from metal-plated plastics.
[0035] Those of skill in the art will appreciate that since each of the rings 10 can be slightly compressed from its original shape that the rings can overcome slight variations in the planarity of the substrate 8 and/or the electronic device 4 . By providing a solder barrier that prevents solder from wicking all the way around a ring, each ring's flexible side walls acts as a small round spring and will deform when a force is directed toward the interior of the ring. When the force is removed, the ring will return to its original shape. The resilient behavior of the rings provide a small, flexible interconnection which can accommodate variations in the planarity of opposing surfaces. Each ring's flexibility also accommodates circuit board or substrate flexing as well as impacts and vibration. The resulting connection between the substrate 8 and an electronic device 4 is more tolerant of substrate and/or device flexing. The connection is also less susceptible to shock or vibration-induced failure.
[0036] While the preferred embodiment of the invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made therein without departing from the spirit of the invention, the scope of which is defined by the appended claims. | Multiple small conductive and flexible hollow rings, each of which is made from a pliable material, provide a flexible connection medium for use between a substrate and a microelectronic device package. Each ring is soldered to both the substrate and the device. A portion of the sidewall of each ring is not soldered thus insuring that at least part of the ring stays flexible. The rings accommodate elevation differences on a substrate and electronic device package. They also provide a vibration resistant and flexible joint. | 8 |
This application is a divisional of application Ser. No. 611,004, filed Sept. 8, 1975, and now u.S. Pat. No. 4,003,187.
This invention relates to a novel microfilm jacket support and microfilm insertion apparatus and process.
BACKGROUND TO THE INVENTION
Prior to the present invention there has been no mechanical apparatus for appropriately inserting microfilm strip(s) into microfilm storage jackets, much less on a rapid pace and efficient and fool-proof basis, as well as the cutting of frames of one subject matter from frames of another subject matter heretofore having been a time-consuming laborious job.
SUMMARY OF THE INVENTION
Accordingly, objects of the present invention include the obtaining of an apparatus and process which overcome and/or avoid problems of the types referred to above, together with other novel advantages.
Another object is to obtain a microfilm jacket support and insertion device facilitating the easy insertion of a microfilm strip thereinto.
Another object is to obtain a microfilm jacket support and insertion viewing apparatus.
Another object is to obtain a microfilm jacket support and microfilm frame-severing device.
Another object is to obtain a microfilm jacket support and film insertion advancing device.
Another object is to obtain a novel microfilm jacket having serially arranged film reservoirs as a belt.
Another object is to obtain a reeled microfilm jacket belt for feeding microfilm jackets serially.
Another object is to obtain a process of microfilm insertion into a microfilm jacket.
Other objects become apparent from the preceding and following disclosure.
One or more objects are obtained by the invention as defined in the preceding and following disclosure.
Broadly the invention may be defined as a microfilm jacket microfilm-inserter device including a support which holds the jacket in a predetermined position with a portion of the reservoir defining structure above the insertion opening at a leading end of the jacket extending beyond a pivot point of support of an underface of the jacket, and including a pressure-applying structure as a microfilm jacket edge-flexing mechanism to bend downwardly the unsupported portion of the leading end of the jacket by applying pressure to an upper surface thereof, adapted such that the opening is broadly exposed of the reservoir space whereby a microfilm end insertion is thereby facilitated. In various preferred embodiments as shall be more fully described in the detailed description, there is included as a part of the unitary combination an insertion mechanism for lining-up microfilm to be inserted with the elongated longitudinal axis thereof aligned lineally with the elongated longitudinal axis of the reservoir space into which the microfilm is to be inserted, and additionally a cutting mechanism for cutting related frames from unrelated frames while within the insertion mechanism or adjacent thereto, and additionally an advancing mechanism, and additionally a structure providing for receipt of desired and/or conventional image projection device(s) at a point adjacent to the point of insertion such that the subject matter about to be inserted may be viewed, this also facilitating the combination element for cutting-away a segment since by the viewer one determines where the related subject matter begins and ends and where the next begins. By the present invention, thereby it is possible to efficiently and speedily review film frames of microfilm at the point of insertion into a storage microfilm jacket at the time of severence of the related strip frames from other frames, by a speedy insertion.
In a further improved and preferred embodiment, there is provided a feed reel mechanism and novel serially arranged microfilm jackets having their longitudinal elongated-axis jacket structures arranged end-to-end consecutively as a continuous belt with intermittent insertion openings, and further preferably also with a take-up reel such that the film jacket is not severed at any time but is merely wound upon a further storage reel, or temporary storage further reel before rewinding upon the original feed reel. The reservoirs may also be additionally in parallel.
It is also contemplated that some of the reservoir channels may be broader than others whether or not serially arranged or with parallel arranged reservoirs.
The invention may be better understood by making reference to the following Figures.
THE FIGURES
FIG. 1 illustrates in side elevation view, an embodiment of a machine for practicing the process of this invention.
FIG. 2 illustrates an in-part view in side view with partial cut-away with one side of an apparatus for practicing the process of this invention, whereby interior mechanism is viewable.
FIG. 3 illustrates a cross-sectional view of a microfilm jacket support structure, and the apparatus of FIG. 2.
FIG. 4 illustrates an in-part and enlarged view of a particular portion of the FIG. 3 illustration, except in a cutting-of-microfilm state, as it would appear when microfilm strip has been severed.
FIG. 5 illustrates an in-part view in elevation plan of a conventional prior art microfilm jacket with film shown in the process of being inserted thereinto.
FIG. 6 illustrates an in-part view in elevation plan of a novel microfilm jacket according to the present invention, operative with the microfilm jacket jacket-microfilm feeding device of this invention, and is in the illustrated view easily compared and contrasted to the prior art illustrated in FIG. 5.
FIG. 7 illustrates in its entirety a typical novel microfilm jacket of the present invention in elevation plan view.
FIG. 8 illustrates an in part view in side cross-section as taken along line 8--8 of FIG. 7.
FIG. 9 illustrates a view as taken along lines 9--9 of FIG. 6, in side cross-sectional in-part view, with the feeding device being shown in phantom for improving understanding of the mechanism of the downward flexing of the leading edge of the microfilm jacket.
FIG. 10 illustrates a view as taken transversely across the width of the microfilm jacket, along lines 10--10 of FIG. 7, in side cross-sectional view.
FIG. 11 illustrates a view extending transversely across the microfilm jacket open mouth in side cross-sectional view as taken along lines 11--11 of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
In greater detail, all of FIGS. 1, 2, 3, 4, 5, 6, 7, 9, 10, relate to the basic common preferred embodiment of the feeding device and microfilm jackets utilizable therewith. The embodiment of FIG. 1 illustrates a feeding mechanism as shall be described in greater detail hereinafter.
FIGS. 1 through 4 illustrate feeding devices for the process of this invention, having a feed and cutter mechanism and a microfilm jacket support carriage mechanism. A cutter-initiating handle 22 causes feed and cutter mechanism structure 63 to pivot downwardly as shall be described in greater detail below. A handle, typically a knob, is utilized typically for revolving to advance microfilm by a turning of a shaft on which shaft also the feed cutter mechanism structure is pivoted. Channel-defining structure 27 defines a microfilm channel seat and mouth 28 for receiving and channeling microfilm, and at location there is a microfilm channel outlet port exit, from which exit microfilm is fed along a channel seat defined adjacent the structure 30 from which channel the microfilm is fed into the open mouth of a microfilm jacket opened by mechanism of the feeding device. In particular, there is an overhang having a lower surface 31, against which upper surface 32 presses, the upper surface 32 being a downwardly inclined surface, and the key 34a coordinating with the key 33 to assure correct alignment.
The upper surface 32 is a part of the overall carriage structure platform 35, pivotably mounted onto a pivot bar with a spring-biased releasable latching lock latchable at any one of alternate positions ranging in directions extending transversely across the width as defined by the alternate-slot-defining structure 36a, and providing a roller track surface 38 for wheel 39 when the carriage platform 35 is being moved laterally from one slot to the other by pressing downwardly on the lever 43a in a manner such that the roller 41 becomes lifted pivotably from a slot recess locking position and state to above the surface 38. Structure 42a and 42b have the wheel 41 mounted thereon while this structure is mounted on the axis, secured to spaced-apart flanges extending downwardly from the carriage platform 35. This relationship can be best seen in phantom illustration of FIG. 3. Lower surface 43b represents an upper surface between the downwardly-extending flanges, against which upper surface 43b the structure 42 normally presses in a locked state as a result of a spring biasing action of a spring viewable in FIG. 3. A lever button 43 while pressing downwardly upon the structure 42, extends upwardly through a through-space 44, in the platform 35. The platform 35 is anchored through an appropriate typically metal strip by an anchoring bolt into a mounting structure. Reel 49, as a feed reel feeds tape 50 into the channel mouth 28 defined by the structure 27. Anchor structure 51b provides for utilization of revolvable handle or knob 51 for adjusting the extent to which the carriage is aligned laterally in one direction or the other, for aligning the end portion 32 appropriately such that in the particular channel to receive microfilm is precisely positioned before the exit port and in series with channel 60, the consecutive channel defined beside the structure 30. Mounting spring-carrying threaded screw or bolt 52 extends through the shaft 54 around which the wheel 53 is rotatably mounted. Accordingly, the shaft 53 is biased by the spring on the bolt 52 into a flush and contacting and rolling relationship with a wheel mounted on the shaft 26, the wheel being fixedly mounted thereon to turn only when the shaft is turned. This relationship is best seen in FIG. 2, in which the opposing relationships of the surfaces of the wheel 53 and the shaft-mounted wheel 55 having surface 56. Position-adjusting bolt 57 adjusts the position at which the pivoting structure 27 normally rests with the channels of feed properly aligned with the ports receiving microfilm therefrom. Accordingly, the bolt 57 has its threaded shaft 57a extending through the structure 27, to rest against the structure 22a. In FIG. 2, in particular, the spring 58 which biases the pivoted structure upwardly into a stable position is also illustrated. In this Figure, the mouth 59 is also disclosed for the channel 60 having the outlet mouth-defining structure 63 defining the outlet mouth 61, from which the film 50 is fed into a concave channel seat 62 located between structures 30, as for example may be seen in FIG. 7. The structure 64 defines therethrough a through-channel 70 overwhich the microfilm may be brought to rest and through which a light from beneath may be shone upwardly into a lens of a microfilm projector arranged.
In the FIG. 3 and FIG. 4 illustrations, the channeling position and structure 63 in the open state is viewable, while in the FIG. 5A it is shown after the cutting handle has been pressed typically in a clockwise direction around its pivot point to cause the structure 63 to move downwardly whereby the upwardly concave angular mouth 61 serves to cut the seat 43. Accordingly, the severed film would then be pushed further into a microfilm jacket channel by further advancing the film severed therefrom in a pushing relationship. Spring 95 on knob 93 biases structures 27 and 94.
FIG. 6 represents insertion details of the microfilm into the novel microfilm jacket of the FIG. 10, the FIG. 8 of the prior art being included in order to more clearly point out differences in prior art state of the art and problems and difficulties associated therewith as contrasted to the novel microfilm jacket and inserting device described above. In particular, with reference to the FIG. 5 illustration, a microfilm jacket 67a has a channel defined between pancaked sheets joined by ultrasonic seals 75a' and 75a". In order to make insertion reasonably possible and speedy, done heretofore substantially always by hand, the film heretofore had to be inserted by virtue of a cut-out section defining a port 71a having a recessed lip 73a away from the forward lip 72a for insertion of the microfilm 50 thereinto. A particular disadvantage of such a prior art situation is that the microfilm frame 74a is left exposed for the frame of a strip on the end thereof last inserted under the conventional system of insertion into such a prior art jacket 67a, the trailing end of the strip of film substantially never being pushed totally beneath the upper sheet beyond the cut-out port 71a, thereby resulting in soiling and deterioration of the microfilm when the prior art jacket 67a was employed, during periods of extended storage and/or use. Moreover, even with the lip recessed in the manner illustrated, in order to provide a ready opening 71a for insertion, there never-the-less still remained several problems with the prior art, namely that when the microfilm 50 is in fact inserted, under the conventional and normal modes of storage, the terminal end of the last portion of the film to be pressed inwardly remains exposed on its upper surface, as noted above, in the cut-away port 71a by virtue of the recessed lip 73a; another difficulty arises from the fact that even with the cut-away, the strip upper and lower sheets of the jacket are held close together thus requiring great care in the insertion by a person, and accordingly taking excessive time to insert each film individually with the personal care of the attendant, to be sure that it is threaded properly between the upper and lower sheets into the channel. Additionally, during the insertion of the leading end of the microfilm 50, great care has to be taken to assure that both of the leading corners become inserted beneath each of the separate angled portions of the lip 73a; otherwise one corner may well be threaded beneath the upper half of the lip 73a while accidently not being threaded below the upper remaining half, whereby at the converging point of the two half portions the microfilm end would be blocked against further insertion unless withdrawn and begun again, getting both corners beneath the upper sheet.
Accordingly, by reference to the FIG. 6 and FIG. 9 in particular, it may be seen how the microfilm 50 with its frames 74, is inserted beneath the upper convex lip edge 73 and above the corresponding lower concave lip edge 72 of the microfilm jacket upper sheet 77"", defining a channel therebeneath between the ultrasonic seals 75' and 75". The forward lip of the microfilm jacket is in a downwardly flexed state as shown in FIG. 11A as would be affected by virtue of pressure of the lower face 31 of the feed device previously discussed and shown in phantom in this Figure, and upward pressure of the lower lip 32 binding the leading edge of the microfilm jacket and providing for the flexing openly of the mouth thereof to expose the channel for insertion of the film 50 thereinto.
In further pointing out the novelty of the present invention, as compared to the prior art as illustrated typically in FIG. 8, it is important to note that in the embodiments of the present invention as illustrated in FIGS. 6, 7, 8, 9, 10, and 11, there is no cut-out providing for insertion of a microfilm, rather there is solely an arced slit necessary -- although it is never-the-less possible to employ with the present inventive feeding mechanism device, the prior art jackets also, the present jackets of the present invention are non-usable by industry in the absence of the novel feeding device of the present invention which provides for the flexing open of the inlet port as shown in the FIG. 9. By virtue of the slits for example as shown in FIG. 7, the slit is totally closed to exclude all dust and debris and exposure to the elements when the microfilm is not in the flexed state, thereby totally enclosing all portions of the microfilm including the trailing edge inserted, as well as the present feedmechanism providing that the severed microfilm strip may be pushed under by the remaining next piece of film being pushed-outwardly to that point and then possibly retracted slightly in order to view the first frame 74. FIG. 10 illustrates a view of the empty channel of FIG. 7 as taken along line 10--10 of FIG. 7. FIG. 12A illustrates a typical appearance of the FIG. 11A embodiment during the state of flexing, viewing the mouth as taken along lines 11--11 of FIG. 9 roll of this continuous microfilm jacket could, for example, be utilized in the embodiment feeder device illustrated in FIG. 1 by the leading edge of the microfilm jacket 67'" of the roll 83 with its rod-space 84, would be mounted with its microfilm jacket feed reel 85, fed through the grooved guide 86, which guide 86 is a stationary guide on the base 87. The base 87 is provided with alternate position selector 88 along which the carriage selector device 89 rides as a part of the laterally to and fro movable structure 90 carried on the rod 91 of the base 87. The structure 90 carries additionally the jacket take-up support structure 91 and reel 92 thereof, while the microfilm is fed from the microfilm feed reel 49a, into the feed and cutter mechanism 17a which is positioned and works substantially as that described and illustrated for FIGS. 2 and 3. Accordingly, the primary distinction between the embodiments of FIG. 2 and FIG. 1, are that in FIG. 2 it is the carriage with platform which is movable laterally to and fro, whereas in the FIG. 1 embodiment, the platform is stationary and it is the feed and cutter mechanism which is movably mounted on a carriage for lateral to and fro movement in order to select the particular channel of a microfilm jacket into which film is to be inserted. The FIG. 1 additionally also illustrating, however, the improved and preferred continuous jacket mechanism with the jacket take-up reel 92 within which the reeled microfilm jacket would be stored various strips of the microfilm cut from the initial microfilm 50 that was initially photographed onto film stored on the reel 49a.
Thus in each embodiment, the film 50 is caused to advance by mechanically turning a handle or knob to turn the shaft 26 together with its fixedly mounted wheel 55 such that surface 56 opposed by surface 53 of the upper biased wheel, causing the film 50 threaded between the opposing wheel surface to advance into mouth 59 and then out of mouth 61 of a common channel, onto the lower concave seat surface 62. The cutter edge or mouth 61 cuts by downward movement when the structure 27 is pivoted by the cutter handle 23, the edge of surface 62 being the opposing cutting surface, whereby the film strip is severed when the mouth edge 61 is pivoted to a state and position shown in FIG. 5A; prior to such cutting, the leading edge would have been threaded into the opened jacket mouth (slit) by virtue of mounting the leasing portion just forward of the mouth such that that leading portion is bent downwardly as shown in FIG. 9. Thereafter, a handle is further turned, pushing the film well-beneath the lip 73.
It is within the scope of the present invention to make such modifications and variations and substitutions as would be apparent to a person of ordinary skill. | In a preferred embodiment, there is provided a microfilm jacket support supportable of a flat microfilm jacket in a horizontal position in an anchored state with a leading edge of the jacket extending beyond the support when mounted thereon, and with a microfilm insertion opening into microfilm jacket reservoir space being positioned at the edge of the support face-up when mounted on the support, and as a part of the combination additionally there being an upper edge pressure-flexing mechanism for flexing downwardly the leading edge extending beyond the support adjacent the insertion opening, and a feeding mechanism for aligning a longitudinally elongated axis of the microfilm with a longitudinal elongated axis of the microfilm jacket reservoir space and with the insertion opening and for feeding advancingly intermittently microfilm into the insertion opening and for intermittently severing microfilm, and additionally for mounting in association with microfilm immediately adjacent the insertion opening a microfilm projecting mechanism for viewing a microfilm frame about to be inserted. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
This patent application claims the benefit of U.S. Provisional Patent Application No. 61/824,046, filed May 16, 2013, which is incorporated herein by reference.
FIELD AND BACKGROUND OF THE INVENTION
The invention relates generally to furniture articles, particularly a line of tables and complementary ensembles that are ideally suited for use on small balconies, terraces, decks or walkways and confined or even irregular shaped areas. More specifically it relates to a furniture line that offers customizable furniture items such as table top shapes, sizes, heights and uses from selectable components while maintaining low cost affordability, ease of assembly and disassembly, essentially by hand, and even use of minimal tools and loose parts.
The furniture field is replete with table constructions for indoor and outdoor uses, and they are available limited as to aesthetics and/or functionality so that purchasers have to accept what is offered or available on the market. Accordingly, there has been numerous sacrifices that had to be made either as to aesthetics, functionality, ease of assembly, costs, or suitability for the intended purpose.
It will be appreciated that this background description is merely an overview to aid the reader, and it is not to be taken as reference to particular prior art, nor, as an indication that any of the deficiencies, disadvantages, or other problems pointed out were appreciated in the art or that they were satisfactorily resolved.
BRIEF SUMMARY OF THE INVENTION
The disclosure describes, in one aspect, a furniture line featuring a customizable table having a top frame, provided selectively in a variety of geometric shapes adapted to receive tops selectable from numerous provided materials and patterns, including solid surface and grids; models with openings for umbrella poles and other accessories; an under mount cross-member coupling system to connect the top frame to a plurality of tubular or rod-like legs, either 3 or 4, in number, the legs being curved and transitioning from vertical to horizontal at upper and lower ends, at least one and preferably two hub-type leg couplers adapted to connect the legs intermediate to their ends and being easily attached and removable; and optionally provided horizontally mountable, rotatable leg levelers to provide stability on uneven surfaces. The disclosed table line provides durability, selection and customization of top shapes, sizes and varying materials, ease of assembly and disassembly, and stability in confined locations on multiple surfaces.
The disclosure also describes various improvements in the ease and versatility of attaching the components by way of alignment, securement and interchangeability providing personalized aesthetics and functions desired by users.
Finally, some of the embodiments disclose companion accessories that enhance the versatility of the table line and show the possible expansion of the features, components and aesthetics to related articles of furniture or other items of décor.
Other objects, features and advantages of the invention will become apparent and explained as the description herein proceeds when considered in connection with the accompanying illustrative drawings, and further by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWING(S)
FIG. 1 is a top down perspective view of an exemplary 3 leg table constructed according to the invention herein;
FIG. 2 is a top down perspective view of another exemplary 3 leg table;
FIG. 3 is a top down perspective view of another exemplary 4 leg table;
FIG. 4 is a top down perspective view of another exemplary 4 leg table;
FIG. 5 is a top down perspective view of another exemplary 4 leg table;
FIG. 6 is a top down perspective view of another exemplary 4 leg table;
FIG. 7 is a top down perspective view of another exemplary 4 leg table;
FIG. 8 is a top down perspective view of another exemplary 4 leg table;
FIG. 9 is a top down perspective view of another exemplary 3 leg table;
FIG. 10 is an exploded perspective view of an exemplary 3 leg table showing the components making up the table and with an umbrella pole;
FIG. 10 a is an exploded perspective view similar to FIG. 10 , for a 4 leg table;
FIG. 11 is a partial exploded view of table top components and with a hook ring, a tubular leg and interlocking plates;
FIG. 11 a is an exemplary exploded view of a top construction and an optional twist-on tubular leg employing interlocking plates;
FIG. 12 is an exploded perspective view of an exemplary cross bar construction for a 3 leg table and a leg hub;
FIG. 13 is an exploded perspective view of a cross bar top construction with the optional twist on tubular leg mounts and a pedestal base;
FIG. 14 is an exploded top perspective view of a pole cup and 3 leg hub;
FIG. 14 a is an enlarged bottom perspective view of a 4 leg hub;
FIG. 15 is a top down perspective view of a table extender with an exemplary top;
FIG. 16 is another top down perspective view of a table top with an alternate top extender;
FIG. 17 is a composite plan view of an exemplary sample of selectable top shapes;
FIG. 18 is a composite plan view showing fragmentary samples of exemplary grid type tops for selection;
FIG. 19 is a front end perspective of a foot leveler component;
FIGS. 20 and 20 a are plan views of the top and bottom respectively, of the leveler of FIG. 19 ;
FIG. 21 is a side plan view of the leveler of FIG. 20 ;
FIG. 22 is an end view of the leveler here being substantially round in shape with a flat bottom;
FIG. 23 is a cross sectional view along the line 23 - 23 in FIG. 22 ;
FIG. 24 is a perspective view of another foot leveler substantially triangular in shape;
FIG. 25 is a side plan view of the leveler of FIG. 24 ;
FIG. 26 is a top plan view of the leveler of FIG. 24 ;
FIG. 27 is yet another plan view of the leveler of FIG. 24 ;
FIG. 28 is a cross-sectional view along the line 28 - 28 of FIG. 27 ;
FIGS. 29 and 29 a are composite views of alternative levelers in a set;
FIG. 30 is a perspective view of another foot leveler here being pentagon shaped
FIG. 31 is a side plan view of the leveler of FIG. 29 ;
FIG. 32 is a side plan view of the leveler of FIG. 30 ;
FIG. 33 is a top plan view of the leveler of FIG. 30 ;
FIG. 34 is an end view of the leveler taken along the line 34 - 34 in FIG. 33 ;
FIG. 35 is an exploded perspective view of a hook rings and tubular leg;
FIG. 36 is a partial perspective view of exemplary legs with levelers exploded therefrom.
FIG. 37 is a bottom plan view of an exemplary table construction here showing a removable assembly;
FIG. 38 is a perspective view of a complementary chair;
FIG. 39 is an exploded perspective view of the chair of FIG. 38 ;
FIG. 40 is a front elevational view thereof;
FIG. 41 is a right side elevational view thereof;
FIG. 42 is a rear side elevational view thereof;
FIG. 43 is a top plan view thereof;
FIG. 44 is a left side elevational view thereof;
FIG. 45 is a bottom plan view thereof;
FIG. 46 is a perspective view of a protective cover for the interlocking plate with lugs;
FIG. 47 is an exploded view of an alternative embodiment of a 4 leg table;
FIGS. 48 , 48 a , and 48 b are a perspective view, a top view, and a side view of the smaller top hub for a 4 leg table;
FIGS. 49 , 49 a , and 49 b are a perspective view, a top view, and a side view of the larger bottom hub for a 4 leg table;
FIG. 50 is a back end perspective view of another embodiment of a foot leveler component here being bulb shaped; and
FIGS. 51 , 51 a , and 51 b are plan views of the end, side, and cross sectional views respectively, of the leveler in FIG. 50 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to the drawings, particularly FIGS. 1-9 , conjointly, there is shown an exemplary table line construction embodied in the present invention and generally indicated at 50 . As shown, each table 50 includes a top 52 with a peripheral frame 54 , a top surface 56 , here being a grid, 3 or 4 leg members 58 , here being curved tubular or rod-like, and a hub 60 intermediate leg ends for fastening the legs together. As illustrated the tables include an opening 62 for an umbrella pole 63 or the like.
In accordance with the present invention, the tables are representative of a furniture line customizable with the table being ideally suited for use on small balconies, terraces, decks or walkways which are confined or have irregular shaped areas. The customization of the tables is implemented by the provision of selectable numbers of a variety of geometric shape frames, corresponding tops, selectable from numerous materials and patterns in solid surface or grids and other options like openings for umbrella or light poles, holders, leg numbers and type, foot levelers and hooks.
Referring to FIG. 10 , the exploded view of components for an exemplary 3 leg table 50 includes a peripheral frame 54 which has an inwardly extending lip 55 on the top edge of the frame wall. The wall is preferably angled with the angle being approximately between 65° and 110° and the optimal angle is about 70°. A top 56 complementary with the frame shape fits into the frame held against the lip 55 . Beneath the top 56 there is provided a cross bar member 64 having arms 66 and a ring 68 forming a spoke-like construction when assembled. The outer arm 66 ends attach to the inner wall of frame 54 to form the top assembly. In this instance the top is provided with an opening 70 for receipt of an umbrella pole 72 . The top opening 70 corresponds to the center ring 68 of the pole member in location which would be the epicenter of the particular shaped table top. A top ring 74 finishes the top. The table legs 58 are vertical intermediate the ends and from the vertical position they curve outwardly and become horizontal at the top and bottom ends.
The bottom horizontal leg portions are provided with a threaded interior inward of the end tip to receive and hold a rotatable foot leveler 75 such as shown in FIGS. 19 to 24 and FIG. 36 .
In order to secure the legs together there is provided a hub 60 which is collar shaped and has vertical semicircular grooves 81 symmetrically spaced about its outer periphery. The legs 58 attach to the collar or hub 60 that has tapped holes 77 (shown in FIG. 14 a ) by way of Allen Head machine screws 78 .
In accordance with the invention, referring to FIGS. 10 and 10 a , the components which make up the table assembly are fairly few in number and capable of being “bin” or inventory parts. This hub 60 available for 3 or 4 leg versions can be stocked for purchase selection. Likewise center tube 68 , ring 74 , and legs 56 in a number of sizes may be stocked. The top frames, tops, and cross-bars are also possible stockable parts according to the number of selectable tables being offered. The accents and other accessories may be further stocked items.
In FIGS. 10 and 10 a there is shown a partial portion of a pole 63 such as for an umbrella (not shown) that passes through the table opening 60 and the collar hub 60 . A stop ring embedded in bottom hub 60 a can be used to limit the height of the pole from the ground.
Alternatively, referring to FIGS. 12 and 14 , a cup member 82 having cylindrical bottom portion 83 and an enlarged rim 84 seats in a groove 85 on collar hub 60 to receive the end of a pole 63 .
An alternative embodiment of a table is illustrated in FIG. 47 . An exploded view of components for an exemplary 4 leg table 250 includes a peripheral frame 254 which has an inwardly extending lip 255 on the top edge of the frame wall. A top 256 complementary with the frame shape fits into the frame held against the lip 255 . Beneath the top 256 there is provided a cross bar member 264 having arms 266 and a ring 268 forming a spoke-like construction when assembled. In some embodiments the top is provided with an opening 270 for receipt of an umbrella pole. The table legs 258 are vertical intermediate the ends and from the vertical position they curve outwardly and become horizontal at the top and bottom ends. In order to secure the legs together there is provided an upper hub 260 and a lower hub 280 . The hubs are collar shaped and have vertical semicircular grooves 281 and 283 symmetrically spaced about their outer periphery. The legs 258 attach to the collars or hubs 260 and 280 that have tapped holes by way of Allen Head machine screws
The upper hub 260 described above is illustrated in greater detail in FIGS. 48 , 48 a , and 48 b . The embedded upper hub 260 can receive a pole end.
The lower hub 280 described above is illustrated in greater detail in FIGS. 49 , 49 a , and 49 b . The embedded lower hub 280 can receive a pole end.
Referring to FIGS. 11 , 11 a and 13 , a tubular leg 88 is provided that is attached with interlocking plates or rings 90 , 92 . The upper ring 92 here shown with lugs 93 attaches to the cross bar structure and the lower ring with slots 94 is affixed to the tubular leg 88 top. Of course, the rings can be reversed and in either case the tube would be attachable and removable with a twisting movement. The lower end of tubular leg 88 attaches to a base 99 which can be round or other shapes. The preferred attachment is by way of similar interlocking plates or rings 90 , 92 a allowing for a twist connection. The pedestal base 99 is here shown as circular, however, it is intended that a number of different geometric shaped bases will be provided for selection.
Another accessory shown in FIGS. 11 and 35 is a hook member 95 which is a ring 96 and a series of single hooks 97 that seats above the tubular leg 88 . Referring to FIG. 35 there is shown a double hook 95 alternative. The hooks can be used to hang articles beneath the table top.
In accordance with another aspect of the invention the table tops may be enlarged when larger surfaces are needed. Referring to FIGS. 15 and 16 , there is shown examples of extenders 100 that fit around the table top 56 providing additional top surface. The extenders are collar like with an interior opening the edge of which is angled to be complementary to the angle of outer edge 54 of the top 56 . It is preferred that the angle is approximately 70°.
In FIG. 15 the top extender 100 is a flat surface while in FIG. 16 the extender is provided with cup holder openings 102 .
As shown in FIG. 17 , an exemplary number of different geometric shaped tops 52 are provided for selection. Each of the shapes can be provided in a selectable number of dimensions. FIG. 18 shows an exemplary number of grid 56 designs that can be provided for selection. The selectable tops can also include solid surfaces made of different materials and with choices of colors and surface designs.
In accordance with another aspect of the invention, foot levelers 75 are provided that are either stationary or rotatable to provide stability on uneven surfaces.
Referring to FIGS. 19-28 , the foot leveler 75 is an elongated body 110 substantially cylindrical with a flat portion 112 . An elongated opening 114 eccentrically located allows the leveler to slide onto the horizontal ends of the table legs. An internal rib 116 snap fits with the annular groove 76 of the table legs.
In FIG. 24-28 the foot leveler is substantially triangular in cross-section and the center opening is eccentrically located so that when rotated there are three different radii to make leveling adjustments.
Another embodiment of a foot leveler is illustrated in FIGS. 49-52 . The foot leveler 275 is bulb shaped and has an elongated body 310 that is substantially cylindrical. In some embodiments, the elongated body may have a flat portion. An elongated opening 314 eccentrically located allows the leveler to screw into the horizontal ends of table leg.
In FIGS. 29 and 29 a there are shown composite sets of slide on foot levelers which have different amounts of lift to level or stabilize a table leg.
FIGS. 30 to 34 show a substantially 5-sided or pentagon shaped in cross section leveler which upon rotation provides 5 different lift radii for leveling a table.
It will be appreciated that other polygonal cross-sectional shapes can be used to provide more or less amounts of lift.
Referring to FIG. 35 there is shown a partial view of a tubular leg 88 which can twist connect to an upper plate 90 (not shown) attached to the table top. Exploded above the leg is shown alternative hook rings 95 with double hooks 101 and with alternative 3 or 4 sets being shown.
Referring to FIG. 37 , there is shown an exemplary underside of a table top where assembly of the frame 50 , cross bar 66 , sleeve 68 and top 56 are done with Allen head screws 78 . This allows the top to be easily disassembled to replace or change a top surface.
In accordance with carrying out the method of the present invention there is shown in FIGS. 38-45 an illustrative complementary chair 120 that is customizable along with a table to make an ensemble.
The chair has tubular or rod-like front legs 122 and back legs 124 . The front legs are bent over rearwardly and provide connection to a seat 126 by way of Allen head screws 78 .
The seat 126 includes a tubular frame and top which can be a solid surface or a grid to match a table top in material and, if desired, substantially in shape.
The rear legs 124 rise up and support a seat back 128 also constructed with a frame and a top like the seat.
The front legs 122 are attached to the back legs 124 by way of Allen head screws. Referring to FIG. 46 , there is shown a perspective view of a plastic protective cover 130 for the lugs of ring or plate 90 whether on the table or a base.
It will be appreciated that the foregoing description provides examples of the disclosed customizable table and furniture line. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosures or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosures more generally. All language of distinction with respect to certain features is not intended to indicate a lack of preference for those features or to exclude such from the scope of the disclosure entirely unless otherwise indicated.
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 for selection or assembly described herein can be performed in any suitable order unless otherwise indicated herein as otherwise clearly contradicted by context.
Accordingly, this disclosure 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 disclosure unless otherwise indicated herein or otherwise clearly contradicted by context.
The designs, shapes, sizes and arrangements shown and described are intended to be illustrative of the versatility and choices that would be available, however, it is not intended that other variations thereof are excluded. | A furniture line featuring a table which is customizable and suited for confined and irregular spaces such as balconies, decks or outdoors which line can be easily assembled or disassembled essentially by hand and available affordably with a variety of selectable tops, shapes and applications. The table features a skeletal frame arrangement with universal top mounts, selectable curved tubular or rod like legs, at least one and preferably two hub couplers or tubular leg and pedestal base, and optional rotatable or slide on levelers for uneven surfaces. A method and system disclosed provides purchaser customization of the table and complementary ensembles. | 0 |
CROSS-REFERENCE
This application is a divisional of U.S. patent application Ser. No. 12/056,752, now U.S. Pat. No. 8,038,685, filed on Mar. 27, 2008, which is a non-provisional of, and claims the benefit of U.S. Provisional Patent Application No. 60/908,367, filed Mar. 27, 2007; the entire contents of each of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to medical apparatus and methods, more specifically to instrument immobilizers and even more specifically, but not by way of limitation to an apparatus and methods for anchoring an intracranial probe or lead to the cranium.
Implanting medical devices within the cranium is an increasingly important approach for treatment of disorders such as Parkinson's Disease, essential tremor and dystonia. This approach may also be used to treat a wide array of neuropsychiatric problems, such as depression, epilepsy, obsessive compulsive disorder, obesity and chronic pain. Most of these devices interact with the brain by delivering current through an implanted probe to modulate brain activity. In addition, infusion of drugs through a permanently implanted probe has been proposed as a primary treatment, or as an adjunctive treatment to electrical stimulation, for Alzheimer's and Parkinson's Diseases, among others.
As part of the implant procedure, the probe must be stabilized in the brain. Ideally, any prosthetic device is attached directly to the tissue on which it operates, in this case, the brain. Direct attachment of electrical and chemical probes to brain tissue is impractical. A more easily implementable solution is a system of flexible probes that bend and float with the brain as the brain moves within the cranial cavity. Such probes are secured to the cranium. In this manner, mechanical forces from outside the cranium are prevented from acting on the brain-to-probe interface.
There are a number of current techniques for securing a probe to the cranium. For example, in one approach, a permanently implanted probe is fixed by a sliding door which closes to form a slot just wide enough to slightly compress and grip the body of the probe. A common feature of such devices is that they grip the probe somewhere within the craniotomy opening, and that the slot has a fixed orientation relative to the cranium.
In another approach, the probe passes through a narrow aperture at the center of a craniotomy opening The probe is held in place by a surgeon as it is bent over into a slot leading to the exit from the device. Hinged arms swing into place to narrow the slot and anchor the probe within the slot.
Current anchoring devices are typically positioned over the craniotomy opening, and they are attached to the cranium with several peripheral screws. An implantable lead is placed through the cranial opening and the lead is gripped by two opposing thin bars. In some cases, it is possible to damage the lead by crushing it between the thin bars. It would therefore be desirable to grip the lead with wider bars to more evenly distribute the gripping force over a greater axial length of the implantable lead. It would also be desirable to provide a more stable mounting for the skull-mounted portion of the anchoring device. Additionally, current devices often have a small opening for receiving the lead and thus it would be desirable to provide an anchoring device having a wider opening for the lead, to permit adjustment of lead position for optimal placement, especially when using a large multi-channel probe array, a feature shared by only a few currently available anchoring systems.
2. Description of the Background Art
Prior patents and publications describing anchors for cranial probes include: U.S. Pat. Nos. 4,328,813; 5,464,446; 6,044,304; 2004/0267284; 2005/0192594; and WO 2004/026161.
SUMMARY OF THE INVENTION
The invention generally provides an anchor for securing an implantable lead within tissues in a patient. The terms “lead” and “probe” will be used interchangeably with one another in this disclosure, as will the terms “anchor base” and “cylinder.” Often the lead may comprise an electrode or a catheter, and the lead is often implanted into brain tissue through a craniotomy in the patient's skull. A current and/or therapeutic agent may be delivered through the lead to the tissue and the anchor is usually composed of materials that are compatible with magnetic resonance imaging. The anchor may be fabricated from metals that do not interfere with MRI and/or polymers such as polyphenylene sulfide, polyetheretherketone (PEEK), polyetherimide, polyimide, polysulfone and the like.
In a first aspect of the present invention an apparatus for securing an implantable lead within tissue of a patient comprises a base that is adapted to be secured to a patient's skull adjacent a craniotomy. The base has an upper surface, a lower surface and a central passage therebetween which is adapted to receive the implantable lead. The apparatus also includes a cover that can be releasably coupled to the base so as to substantially cover the central passage and also to capture the lead therebetween. A first rotating member or door, is coupled with the base and is rotationally movable so as to meet and engage the lead at a plurality of positions within the central passage. Rotating the door also adjusts the position of an opening within the central passage in which the lead may pass through and also closes or reduces the size of the central passage while still allowing the lead to pass therethrough.
Often, the first rotating member comprises a removable insert that is adapted to releasably grip the lead and that may be received in a recessed region of the rotating member. The removable insert is usually adapted to be removably coupled to the first rotating member with a rotationally actuated tool that may be coupled to the first rotating member. The first rotating member may have a surface defining a wedge shaped or indented region that is adapted to receive and align the tool.
The apparatus may have a pin or rivet engaged with the first rotating member that secures the first rotating member to the base while allowing rotation of the first rotating member relative to the base. The first rotating member may also have a surface that defines a receptacle that is adapted to receive a tool for turning the first rotating member into a desired position so as to engage the lead and fix the lead into a position. The first rotating member may further comprise a resilient end that is adapted to releasably grip the lead. The resilient end may lie in the same plane as the first rotating member and may be composed of an elastomer. The resilient end often is constructed with a substantially solid core while sometimes it may be porous. Often the resilient end comprises surface features that are adapted to capture the lead. The surface features may include a plurality of convex or concave regions adjacent to one another or the surface features may be scallops. Sometimes the surface features may comprise a plurality of resilient fingers that extend outward from the resilient end. The surface features may also comprise combinations thereof.
The apparatus may further comprise a ratchet mechanism that is adapted to restrict the first rotating member to motion in one direction. Often the apparatus also comprises a fixing element such as a set screw that is adapted to immobilize the first rotating member. The apparatus also often comprises a second rotating member that is coupled with the base and a spacer may be used to separate the first and second rotating members from one another. The second rotating member is rotationally movable so as to meet and engage the lead at a plurality of positions within the central passage. Rotating the second door also adjusts the position of an opening within the central passage in which the lead may pass through and also closes or reduces the size of the central passage while still allowing the lead to pass therethrough. Usually, the first and second rotating members are movable independently of one another and they may be retained in the base with a retaining member such as a ring. Also, the first and second rotating members may lie in the base adjacent to one another. Sometimes the second rotating member comprises a removable insert that is adapted to releasably grip the lead. The insert on the second rotating member may take the same form as the insert on the first rotating member. Often the resilient end on the first rotating member lies in a plane between the first and second rotating members.
The apparatus may further comprise a locking mechanism coupled with the first and second rotating members. The locking mechanism locks the first and second members together thereby preventing relative motion therebetween. The locking mechanism may be a detent and comprise a protuberance on either the first or second rotating member and a receptacle for receiving the protuberance on the other rotating member. These features allow the rotating members to snap into position with one another thereby ensuring the lead is gripped therebetween.
Often, the apparatus further comprises one or more tabs that extend radially outward from the base. The tabs are adapted to be secured to the skull adjacent the craniotomy. The tabs often define apertures that can receive a fastener such as a screw, thereby securing the base adjacent the craniotomy.
Sometimes the base is cylindrical and may be sized to fit at least partially within the craniotomy, and at least a portion of the base may be securely press fit into the craniotomy. The base may comprise a discrete upper and a discrete lower portion that are fastened together, or the base may be of unitary construction. The base may be recessed at least partially into the craniotomy, or the lower surface of the base may sit substantially flush with the top of the skull. The base may also have one or more receptacles that are adapted to releasably receive at least a portion of the cover. Often, the upper surface of the base defines one or more channels that are sized and shaped to accept the lead after the lead has been disposed therein. The base may also be adapted to receive and retain other surgical instruments such as instrument positioning guides or other reference devices often used during neurosurgery. These other surgical instruments may releasably lock with a flange in the base, a retaining member in the base or any other portion of the base or components therein.
Often the cover is adapted to be removably coupled to the base. Sometimes the cover comprises one or more legs that are adapted to releasably snap fit into engagement with the base. Alternatively, the legs may be disposed on the base or on a retaining member that fits in the base. The cover may have a surface that defines one or more channels that are sized and shaped to accept the lead after it has been disposed therein. One or more plugs may be placed into the channels or a gasket may be disposed between the cover and the base in order to seal any gaps therebetween.
In another aspect of the present invention, a system for securing an implantable lead within tissue of a patient comprises an apparatus for securing the implantable lead within tissue. The apparatus comprises a base adapted to be secured to a patient's skull adjacent a craniotomy, the base having an upper and lower surface and a central passage therebetween. The implantable lead is often disposed in the central passage. The apparatus also comprises a first rotating member coupled with the base and having a removable insert adapted to engage the lead. A retaining pin may couple the insert with the first rotating member. The first rotating member is rotationally movable so as to meet and engage the lead at a plurality of positions within the central passage. Rotating the door also adjusts the position of an opening within the central passage in which the lead may pass through and also closes or reduces the size of the central passage while still allowing the lead to pass therethrough. The system also includes a tool having a proximal end, a distal end and a handle, the tool being adapted to introduce and remove the removable insert to or from the first rotating member.
Often the tool also comprises a pin disposed near the distal end that is adapted to retain the insert when the insert is decoupled from the first rotating member. The tool is usually adapted to be rotated so as to simultaneously engage the insert and withdraw the retaining pin from the insert. The tool may have an angled surface that facilitates seating of the tool against the first rotating member.
The system may also include a cover that can be coupled to the base so as to substantially cover the central passage and also to capture the lead therebetween. The system may also comprise a potting material that is used to fill gaps between the base and the craniotomy in order to reduce or eliminate leakage of body fluids, such as cerebral spinal fluid (CSF), from around the base.
In another aspect of the present invention, a method of securing an implantable lead into tissue of a patient comprises positioning a base having an upper surface, a lower surface and a central passage therethrough, adjacent a craniotomy in a skull of a patient. The base may be secured adjacent the craniotomy and to the skull and an implantable lead is inserted through the central passage into the tissue. Rotating a first rotating member that is coupled to the base moves the rotating member so that it meets and engages the implantable lead at a plurality of positions within the central passage.
The method may also comprise the step of rotating a second rotating member that is also coupled to the base so as to meet and engage the lead at a plurality of positions within the central passage thereby securing the lead in the tissue. Rotating the second door also adjusts the position of an opening within the central passage in which the lead may pass through and also closes or reduces the size of the central passage while still allowing the lead to pass therethrough. The method may also include rotationally adjusting the first and second rotating members in order to capture the lead therebetween or to release the lead therefrom. Often the method includes attaching and/or removing an insert that is adapted to engage the lead and that is coupled to the first or second rotating members.
The method may also comprise inserting one or both of the two rotating members into a secure base ring intraoperatively. In early stages of the lead implantation procedure, a wide lumen is available. After the lead is placed, an opening in such rotating members allows them to pass around the lead and rest in the base, and grip the lead. The method may further comprise retaining the two rotating members within the base by interlocking a retaining member placed over the rotating members and within the base, thereby restricting axial movement of the rotating members relative to the base.
Sometimes securing the base comprises press fitting at least a portion of the base into the craniotomy and often securing the base comprises coupling the base to the skull adjacent the craniotomy with a fastener such as a screw. Sometimes securing the base comprises recessing at least a portion of the base in the craniotomy, or the base may be coupled adjacent the craniotomy such that a bottom surface of the base is substantially flush with the craniotomy.
Usually, a cover is engaged with the base so as to substantially cover the central passage and capture the implantable lead therebetween. The cover and/or base may have channels which can accept the lead after being positioned therein. Often the first and second rotating members are locked and this may be accomplished by threadably engaging the rotating members with a set screw or by using detents in order to prevent relative motion therebetween. Sometimes, the lead may be bent into a channel that is defined by a top surface of the base and a potting material may be applied in order to fill gaps between the base and the craniotomy, thereby reducing or eliminating leakage of body fluids such as CSF from around the base.
These and other embodiments are described in further details in the following description related to the appended drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1D illustrate cross-sections of several anchor assembly embodiments having fixation tabs that allow the anchor to be placed within a craniotomy at varying depths.
FIG. 1E shows an anchor attached to a patient's cranium.
FIGS. 2A-2G show top and cross section views of rotating doors.
FIGS. 3A-3F show alternative embodiments of the grip bars.
FIGS. 4A-4F show alternative embodiments of the rotating doors.
FIG. 5A shows a top view of the cylinder without the rotating doors.
FIG. 5B shows a side view of an exemplary embodiment of a cover.
FIG. 5C shows a bottom view of an exemplary embodiment of a cover.
FIG. 6A shows a cross section view of an assembled anchor with rotating doors.
FIGS. 6B-6K show the components of the anchor depicted in FIG. 6A .
FIG. 7A shows an alternative embodiment of a mechanism for retaining the moving members within the cylinder.
FIG. 7B shows a bottom view of the anchor assembly in FIG. 7A .
FIGS. 8A-8C show an anchor base of unitary construction.
FIGS. 8D-8M show various components in various stages of assembly with the anchor base of FIGS. 8A-8C .
FIGS. 9A-9C illustrate the use of set screws to lock the rotating doors in position.
FIGS. 10A-10J show the use of a tool for placement and removal of inserts into the rotating doors.
FIGS. 11A-11D show side views of a tool as it us used to insert, place, attach and detach inserts into the anchor.
FIGS. 12A-12C show an alternative embodiment of rotating doors that are adapted to pass around a placed lead intraoperatively and snap together.
FIGS. 13A-13C show an alternative embodiment of the anchor base which may be used with the doors of FIGS. 12A-12C .
FIGS. 14A-14E illustrate exemplary embodiments of retaining members which hold the rotating doors in the anchor base.
FIGS. 15A-15D illustrate an exemplary embodiment of a retaining member which retains the rotating doors and the cap.
FIG. 16 illustrates an exemplary embodiment of an anchor base with rotating doors that are held in place with a retaining member.
DETAILED DESCRIPTION OF THE INVENTION
In the drawings like numerals describe substantially similar components. Now turning to FIG. 1A is a cross section exploded view of the anchor assembly, showing the probe 5 , cap 200 , and cylinder body 10 , also referred to as an anchor base in this application, assembled with parts that grip the probe. In this embodiment, the radial tabs 20 are elevated relative to the bottom surface of base 10 so that the cylinder body 10 may be recessed into a craniotomy. The cylinder 10 is fixed to the cranium by screws which pass through openings 25 in tabs 20 and secure the tabs to the cranium. In an alternative embodiment, the cylinder may have ridges, protrusions or other surface features (not shown) which generate a friction fit with the wall of the craniotomy, in conjunction with or in lieu of the radial tabs. Rotating doors 110 and 120 are shown rotated to a position such that the grip bars 70 are positioned to grip the probe 5 . In the section shown in FIG. 1A , the grip bars 70 are positioned by removable inserts 140 and 150 , which in turn are captured in the doors 110 and 120 by rotating rivets 130 . An upper rivet plate 134 and a lower rivet plate 136 coupled to rivet 130 help lock the inserts into position. A ring-like spacer 16 separates doors 110 and 120 . The cap 200 has legs or pins 220 with catches 225 which snap into receiving sockets 40 within the cylinder 10 . The receiving sockets 40 not only provide fixation for a cap, but also provide a site and mechanism for attaching other instruments to the device. Examples of other devices that could be attached thereto include positioning guides or other reference instruments commonly used during neurosurgery.
The grip bars 70 may be made of a soft material, for example an elastomer, such as silicone rubber, polyurethane, or Santoprene™, or they may be made of the same material as the doors. Grip bars 70 may be porous or have holes running through them to make them compressible. Pores could be produced by many methods, including gas bubbles forming during the curing process, dissolving filler materials, or by withdrawing filaments introduced at the time the bars are formed or molded. During implantation, the probe 5 is placed intracranially, and the rotating doors 110 and 120 are rotated to place the grip bars 70 against the probe 5 . The probe 5 is bent to course along a groove 30 on the superior surface of the cylinder 10 , and onto the surface of the cranium. The cap 200 is then lowered so that pins of the cap 220 are inserted into sockets of the cylinder 40 , and the cap presses against the probe 5 . In some embodiments, a groove in the cap 210 wraps around the probe 5 . As the cap is lowered, pins 220 and protrusions from the pins 225 are displaced towards the center of the cylinder by catches 45 , until the protrusions snap outward under the catches, retaining the cap. In other embodiments, the cap may have an elastomeric gasket shaped so as to seal the space between the cap and the base, except for allowing passage for the probe through one set of grooves 30 and 210 . In other embodiments, the elastomeric gasket shall leave all sets of grooves open, and the unused probe passages are filled with separate plugs with radial dimension similar to the probe.
FIG. 1B shows the embodiment of FIG. 1A with the probe 5 positioned intracranially, and the cap 200 snapped into the closed position. In this embodiment, the tabs 20 are elevated so that cylinder 10 may be recessed in the craniotomy allowing the top of the cylinder to be substantially level with the cranium. Such an embodiment has the advantage that the top of the cap extends minimally above the cranium.
FIG. 1C shows an alternative embodiment of the assembly shown in FIGS. 1A-1B , in which the cylinder 10 is partially recessed into the cranium. FIG. 1D shows an alternative embodiment of the assembly shown in FIGS. 1A-1C , in which the tabs 20 are positioned so that the lower surface of the cylinder 10 is at the level of the outer surface of the cranium. Such an embodiment has the advantage that the craniotomy opening need only be as large as the inner lumen of the cylinder 10 . The rotating door grip mechanism provides the particular advantage that if the probe 5 is inserted through the center of the device as shown in FIG. 1B , the doors may be rotated together, thereby rotating the probe while still retaining vertical fixation.
FIG. 1E illustrates the anchor base or cylinder 10 attached to a patient's cranium C. In FIG. 1E , anchor 10 is positioned over a craniotomy so that a portion of the anchor fits within the craniotomy opening in order to reduce the portion of anchor 10 protruding out of the patient's cranium C. Fixtures F such as screws removably couple the anchor 10 to the cranium and a lead 5 is place through the central opening of the anchor 10 into the patient's brain B. A cover 200 may then be snap fit into engagement with the anchor 10 , thereby capturing the lead 5 in a desired position.
FIG. 2A shows the lower rotating door 120 , apart from the rest of the anchor. The door is a disk with a large cutout 122 within its interior. Along one edge of the cutout is a bar 70 which can grip the probe placed in an intracranial position. Near the bar is a ledge depressed into the door 80 into which a gripping insert can be placed. The insert is retained from movement towards the open portion of the disk by terminating the depression at two stops 85 . FIG. 2B shows both rotating doors overlayed, with the both rivets 130 in the open position and both inserts removed. In this configuration a relatively large opening in the center of the anchor is available for the probe or any related test or accessory instrumentation.
FIG. 2C shows the upper rotating door 110 with the rivet 130 in the closed position, and gripping insert 140 in place. The upper door also has a cutout 112 , a gripping bar 70 and a place for seating the insert. The insert 140 rests on the depressed ledge 80 . Motion of the insert towards the open part of the door 140 is prevented by the stops 85 , as in the lower door. Motion of the insert up out of the ledge, or rotation of the insert out of the ledge is prevented by the rivet 130 . The upper plate of the rivet 134 is a partial disk. When it is in the closed position, as shown in FIG. 2C , the upper plate covers the edge of the insert, so that it is locked into place on the depressed seating ledge 80 . When it is open, the insert may be removed. The upper plate has three sockets 132 which may accept prongs from an insertion and removal tool, in order to rotate the rivet. A lower plate of the rivet 136 is similar to the upper plate 134 and also helps hold the insert. Lower plate 136 may be seen in FIG. 1A .
FIG. 2D shows a side view of the two rotating doors 110 , 120 , with the inserts 140 , 150 in place, and the rivets in the closed position. When the rotating doors 110 , 120 are rotated, the inserts are pushed toward each other by their corresponding doors. FIG. 2E shows the two rotating doors 110 , 120 overlayed, with the inserts locked in place by the rivets 130 . FIG. 2F also shows the two rotating doors overlayed, with the inserts removed and the doors opened to their maximum aperture. FIG. 2G shows both top and side views of the two inserts 140 and 150 . The head or top portion 164 of insert 150 along with the head or top portion 162 of insert 140 is seen in the side view of FIG. 2G . The divots in the inserts 165 , 166 accommodate the rivets. When the rivets are rotated into the closed position, the tails of the inserts 160 fit between the head of the rivet 134 and the seating depression in the rotating door 80 . When the inserts are in place, their grip bars 70 are continuous with the grip bars of the rotating doors. The tails of the inserts 160 sit in recessed ledges 80 in the rotating doors.
FIGS. 3A-3F show alternative embodiments of the grip bars 70 , with greater contact between the grip bars and the probe compared to the embodiment shown in previous Figures. Only views from above are shown. In FIG. 3A , the grip bars are scalloped to conform to the shape of the probe, and the spacing between scallops is less than the diameter of the probe, allowing many prospective positions where the probe could be placed. In FIG. 3B , the grip bars are also scalloped, but with a shape complementary to the shape in FIG. 3A . This shape generates as many prospective positions as the shape in FIG. 3A , but instead of apposing the probe with conforming surfaces, this shape contacts the probe at 4 points, compared to two points in the embodiment shown in the other Figures. In FIG. 3C , the grip bars completely surround the probe, generating fewer prospective fixation positions compared to the embodiments of FIGS. 3A-3B . In FIG. 3D , thin flanges or resilient fingers protrude from the grip bars, such that the flanges from one grip bar are out of phase or alternate with the flanges from the other grip bar. FIGS. 3E-3F are similar to the embodiment of FIG. 3D , except that the flanges on opposite grip bars are in phase with one another so that they oppose each other, rather than the out of phase or alternating pattern seen in FIG. 3D . FIG. 3E has longer flanges, while FIG. 3F has shorter flanges. These different embodiments illustrate examples of how the contact area of the grip bar with the probe may be increased compared to the embodiments shown in the other Figures.
FIGS. 4A-4F show alternative embodiments of the grip bars 70 , with one or both grip bars attached directly to the rotating door 110 , 120 , without an insert or the possibility of removing a portion of the grip bar 70 . In FIGS. 4A-4D , the grip bars are centered on a plane between the rotating doors, as in FIG. 2D , while in FIGS. 4E and 4F , the grip bars 70 are centered in the planes of their respective rotating doors. When the grip bars are centered on a plane between the rotating doors, they do not transmit a bending moment to a probe inserted parallel to the axis of the cylindrical anchor body, while the embodiment in FIGS. 4E-4F the grip bars could potentially transmit a bending moment to such a probe.
FIGS. 4A-4B show an embodiment with an upper rotating door 110 similar to the embodiments shown in FIGS. 2A-2G , while the lower rotating door has no insert, and its grip bar is one continuous member. FIG. 4A shows the rotating doors in position to grip the probe, while FIG. 4B shows the rotating doors opened to their maximum aperture. The maximum aperture of this embodiment is nearly the same as the maximum aperture illustrated in FIG. 2F , except near the center of the cylinder.
FIGS. 4C-4D , show an embodiment in which neither rotating door has an insert, and both grip bars are single, continuous members. FIG. 4C shows the rotating doors in position to grip the probe, while FIG. 4D shows the rotating doors opened to their maximum aperture. In this embodiment, the maximum aperture is smaller than in the embodiments of FIGS. 2A-2G and FIGS. 4A-4B .
FIGS. 4E-4F show an embodiment in which neither rotating door has an insert, and
both grip bars 70 are single, continuous members, as in FIGS. 4C-4D . FIG. 4E is a cross section view, which shows that in this embodiment the grip bars 70 are centered in the plane of their respective rotating doors. FIG. 4F shows that the maximum aperture of this embodiment is wider than any of the other illustrated embodiments, except near the center.
In other embodiments, the grip bars could be attached directly to the rotating doors for their full length, without any inserts or rivets. It will be obvious to those skilled in the art that many other specific forms are possible.
FIG. 5A shows a top view of the cylinder or anchor base 10 , without the rotating doors. The anchor is fixed to the cranium by screws through screw-holes 25 in radial tabs 20 . A relatively short set screw 50 inserts into a threaded hole 56 to impinge upon the upper rotating door 110 , (not shown) and lock it into place. A relatively long set screw 52 having a flat point 51 inserts into a threaded hole 56 to impinge upon the lower rotating door 120 , (not shown) and lock it into place. Another relatively long set screw 54 having a cone point 55 inserts into a threaded hole 56 to impinge upon both rotating doors 110 and 120 (not shown) and lock them into place. In the illustrated embodiment, screws 50 and 52 have a flat tip, and impinge upon the outer upper corner of the rotating doors, while the screw 54 has an angled tip, and impinges upon the flat edge of both rotating doors. Receiving sockets 40 having catches 45 are adapted to receive the cap thereby snap fitting the two components together. Additionally, grooves or channels 30 radially extend outward from anchor 10 and provide a channel for holding the lead when the lead is captured between the anchor 10 and the cap.
Alternatively, one of the rotating doors could be held in place by a one-way ratcheting mechanism. In such an embodiment, a no-back pawl is a beam integrated with the anchor cylinder, in the plane of one of the rotating doors. The outer edge of the corresponding rotating door has the gear teeth. The pawl permits the gear teeth to pass freely in the direction which moves the grip bar 70 towards the probe, closing the door, but prevents the rotating door from opening Such an embodiment makes fixing the doors faster, as only one set screw must be tightened, yet still permits the opening between the doors to be adjusted to any angular position, multiple times if necessary.
FIG. 5B shows a cross section view of the cap 200 . It is dome shaped. Three pins 220 protrude downward, one of which is visible in this view. FIG. 5C shows a bottom view of the cap. The shape is a dome, truncated adjacent to pins 220 which protrude downward to snap into sockets 40 in the cylinder 10 . The dome-shaped disk is truncated adjacent to the pins so that a tool may be inserted into the socket 40 , alongside a pin 220 to facilitate removing the cap 200 when necessary. In the preferred embodiment, grooves 210 in the cap 200 increase the area of the cap 200 contacting the probe, compared to grooveless embodiments. FIG. 5C shows a bottom view of cap 200 highlighting grooves 210 and pins 220 .
Initially the probe is gripped by the rotating doors and fixed into position. The probe is then bent to lay in grooves 30 on the upper surface of the cylinder. The cap is lowered, with pins 220 sliding into sockets 40 and protrusions 225 from the pins snapping into place under catches 45 . When the cap is snapped in place, it presses upon the probe. In the preferred embodiment, grooves in the cap 210 increase the surface area of the cap in contact with the probe, increasing stability and decreasing point pressure on the probe.
FIG. 6A shows an exemplary embodiment of an anchor base assembled with all of its components. FIGS. 6B-6K show the various components of the assembly in FIG. 6A . In FIG. 6A , the anchor base is composed of upper 12 and lower 14 portions. In the illustrated embodiment, radial tabs 20 are attached to the upper portion 12 of the cylinder 10 , so that the cylinder may be recessed into the craniotomy opening In other embodiments the tabs may be attached to the lower portion 14 of the cylinder 10 . A shelf 26 , which retains the moving members within the cylinder, is integrated into the lower portion of the cylinder 14 . The upper portion 12 of the cylinder is the more massive, because it must contain the threaded holes 56 for the set screws (seen in FIG. 6B ). Within the cylinder the upper 110 and lower 120 rotating doors are separated by a spacer ring 16 . The upper 12 and lower 14 portions of the cylinder are attached by an adhesive. In alternative embodiments, the base could be attached by welding or other mechanism of plastic deformation, by screws or other mechanisms which will be obvious to those skilled in the art. FIG. 6B shows the upper 12 portion of the anchor assembly while FIG. 6C shows a cross-section take along line 6 C- 6 C and FIG. 6D shows a cross section taken along line 6 D- 6 D. FIG. 6E shows the upper door 110 with insert 140 and rivet 130 that is positioned in the upper 12 portion of the anchor assembly. A spacer ring 6 F is then positioned next in the anchor assembly and a cross section of ring 16 taken along line 6 G- 6 G is shown in FIG. 6G . Next lower door 120 with rivet 130 and insert 150 is loaded into the anchor assembly. The lower 14 portion of the anchor base is seen in FIG. 61 . When the lower portion 14 is fastened to the upper 12 portion, the upper and lower doors 110 , 120 and spacer 16 are captured therebetween. FIG. 6J shows a cross section of lower portion 14 taken along line 6 J- 6 J and FIG. 6K shows a cross section of lower portion 14 taken along line 6 K- 6 K.
FIGS. 7A-7B show an alternative embodiment of assembling the anchor employing a plurality of pins 17 penetrating the anchor cylinder wall, and extending beneath the lower rotating door 120 . The pins course through narrow channels 18 in the cylinder wall. Together, the pins provide a support that retain the moving members within the cylinder. FIG. 7A shows a cross section of the anchor assembled with all of its components and FIG. 7B shows a bottom view of the anchor base with channels 18 . It is clear to those skilled in the art that this embodiment may be combined with the embodiments shown in FIGS. 6A-6I and FIGS. 8A-8M . In embodiment of FIGS. 6A-6I , the pins would provide the additional advantage of helping to retain the base of the cylinder. In the embodiment of FIG. 5 , the pins provide further support for the moving members around the cutout that facilitates insertion of the rotating doors 28 .
FIGS. 8A-8M show an alternative embodiment of an anchor assembly employing a different assembly method. In this embodiment, the body of the cylinder is monolithic. The bottom of the cylinder has a shelf 26 which retains the moving members. One side of the shelf is cut away 27 so that the rotating doors may be inserted from below during assembly. Such an embodiment is most compatible with a cylinder body which recesses into the craniotomy, because in such embodiments the slot is not impeded by the radial attachment tabs 20 . To assemble this embodiment, the upper rotating door 110 is slid into the central chamber of the cylinder. Next, the spacer 16 is inserted below the upper rotating door. Finally, the lower rotating door 130 is inserted. One side of the bottom of the cylinder is cutout 28 to facilitate sliding the rotating doors and the spacer parts into the center of the cylinder. The rivets 130 may be attached to the rotating doors in sequence after each is inserted into the central chamber, or after both rotating doors have been inserted. The rotating doors may be prevented from exiting the central chamber by tilting the slot slightly, so that the final door is strained as it is inserted and then snaps into place, or by placing one or more pins in the slot opening so as to constrain the motion of the lower door to rotational motion only. Alternatively, in both of these embodiments, an extended shelf may be fixed in the entry slot. FIG. 8A shows the anchor base that holds the upper 110 and lower 120 rotating doors. FIG. 8B shows a cross section of the anchor base of FIG. 8A taken along line 8 B- 8 B and FIG. 8C shows a cross section of the anchor base taken along line 8 C- 8 C. FIG. 8D shows the bottom of the anchor base and FIG. 8E shows the anchor base after upper door 110 has been inserted into the base. FIG. 8F shows the anchor base after both upper 110 and lower 120 doors and spacer 16 have been loaded into the anchor base. FIGS. 8G-8L illustrate the sequence of loading components into the anchor base during assembly and FIG. 8M shows the assembled anchor.
FIGS. 9A-9C show cross section views, illustrating how set screws can be positioned in three different positions, so as to impinge on the upper rotating door 110 alone, lower rotating door 120 alone, or on both rotating doors 110 , 120 simultaneously. Exemplary embodiments are shown, illustrating how the rotating doors may be fixed with standard set screws. Small diameter screws, such as 0-80, are appropriate for this application, because the cylinder body 10 is thin. A thin body 10 is desired so that it does not protrude much above the surface of the cranium.
FIG. 9A shows a set screw 50 positioned to fix the upper rotating door 110 . In this embodiment, a flat set screw is used. The tip of such a screw typically has a wide flat surface orthogonal to the screw's axis of symmetry, bounded by a narrow conical ring 51 . When the screw is deployed with its long axis tilted at approximately 30 degrees from horizontal, one edge of the conical ring is nearly parallel to the outer edge of the upper rotating door 110 . As the screw is tightened, the conical ring 51 impinges upon the outer edge of the upper rotating door, but away from the lower rotating door 120 .
FIG. 9B shows a similar set screw 52 positioned to fix the lower rotating door 120 . This screw is similar to the upper door fixation screw 50 , except that it is longer. FIG. 9C shows a set screw 54 positioned so as to impinge upon both rotating doors 110 and 120 simultaneously. In this embodiment a cone-point set screw is illustrated. Such a set screw has a wide conical ring 55 terminating at the tip of the screw, with a tip angle of approximately 118 degrees. When the screw 54 is deployed with its long axis tilted approximately 60 degrees from horizontal, it fixes both rotating doors.
FIGS. 10A-10J show an insertion tool 300 with handle 350 for placement and removal of inserts 140 and 150 into the rotating doors 110 and 120 . FIGS. 10A-10F show portions of the tool 300 from several views. A side view of the tool is seen in FIGS. 10A-10C and the tool is seen from a top view in FIGS. 10D-10F . FIGS. 10A and 10D show only the lowest portion, which interfaces directly with the insert, rotating door, and upper plate of the rivet. An orienting edge 320 at the bottom of the tool is complementary to the shape of the upper plate of the rivet 134 . Tabs 310 at the bottom of the tool fit precisely into matching sockets 132 in the upper portion of the rivets. In an alternative embodiment of the tool and the top of the rotating rivet, the tabs 310 are slightly larger at their lower most position, and/or the sockets 132 are narrower at their upper most position, to facilitate a snap fit of the tool with the rivet rotor.
FIGS. 10B and 10E show a platform 340 at the base of the insertion/removal tool. The platform forms a bridge between the small features and tight tolerances of the components shown in FIGS. 10A-10B , and the grip or handle 350 through which the surgeon applies torque, is shown in FIGS. 10C and 10F . In the embodiment illustrated, the grip 350 is a hexagonal post with an angled handle, which may be turned digitally or with a wrench. In other embodiments, the grip may take another form, for example, a cap screw. In another embodiment, it could be a cylindrical post, with one or a plurality of radial holes into which a lever arm can be inserted.
FIGS. 10G-10J show how the tool mates to the upper plate of the rivet 134 and couples with an insert 150 on lower rotating door 120 . The lower portion of the tool has an angled shape 320 complementary to the edge of the upper plate of the rivet 134 , to facilitate alignment of the tool with the rivet, and to apply torque to the rivet as the tool is rotated. For fine positioning and additional torque, the tool has tabs 310 which insert into matching divots in the upper plate of the rivet 132 . A curved pin 335 holds an insert 140 or 150 in position next to the tool 300 while the insert is placed into or removed from a rotating door 110 or 120 . A bulge 330 is provided for mounting the pin 335 . This mounting bulge 330 is positioned so that it does not impinge upon the upper portion of the insert 140 as the tool is rotated.
FIGS. 11A-11D show the tool and insert through the cycle of positioning, attachment and detachment. In FIG. 11A , two insertion tools are above the anchor, and the inserts are seated in the rotating doors, retained by the rivets. In FIG. 11B , the tools are lowered to a position adjacent to the upper portion of the rivets 134 and the inserts 140 and 150 . The inserts are seated in the rotating doors, retained by the rivets. In FIG. 11C , the tools have been rotated as indicated by the double headed arrows, so that the holding pins retain the inserts to the bottom of the insertion tools. The rivets no longer retain inserts. In FIG. 11D , the inserts 140 and 150 are retained against the insertion tools by the holding pins 335 and lifted away from the rotating doors. The lower surface of the insertion tool fits into divots 165 and 166 , (not shown) in the inserts, so that the insert has a definite position relative to the insertion tool. The rotating doors and rivets lie below the tool as the tool is lifted away.
FIG. 12A-12C show an exemplary embodiment of the rotating doors adapted for intraoperative assembly. In FIG. 12A the rotating doors 110 and 120 have gaps 71 positioned so that they can be passed around an indwelling medical lead and placed in a receiving anchor base. The gaps 71 may be positioned as in FIG. 12B , so that the doors may be passed around the lead in a single movement. Intraoperative handling is facilitated by holes 74 in the doors. Once inserted into the receiving base, the doors can be rotated as in FIG. 12C in order to grip the medical lead. A snap mechanism can operate whereby a protrusion or detent from one door 73 lodges into a cavity 72 on the other, so as to maintain the doors in apposition against the lead.
FIGS. 13A-13C show exemplary embodiments of the anchor base 10 and cap 200 adapted for intraoperative assembly with doors such as shown in FIGS. 12A-12C . In the exemplary embodiment of FIG. 13C , base 10 has two tabs 20 for attachment to the cranium, but the number of tabs may be modified as required. The doors pass around the lead, and they are placed so that the lower door rests upon a shelf 26 , and the upper door rests upon the lower door. A retaining member, such as those illustrated in FIGS. 14A-14E may optionally be inserted interfacing with an annular groove 41 in such a way as to partially occlude the lumen of the base 10 and prevent removal of the rotating doors. Two embodiments of the cap 200 are shown in FIGS. 13A and 13B , with pins 220 placed so that the cap 200 can be attached to the base 10 by protrusions 225 from the pins 220 into the annular groove 41 . In the embodiment of FIG. 13B , cavities 226 are placed in the cap 200 , so as to extend the effective length of the pins 220 and control the strain of the pin and mating forces, as will be familiar to those skilled in the art. The annular groove 41 can also be a point of attachment for additional instruments used intraoperatively such as a positioning guide or other reference instruments often used during neurosurgery. The retaining member may similarly be modified to permit attachment of other instruments used intraoperatively. The base 10 and cap 200 could optionally have features to force a particular alignment of the cap and base. For example, a pin may extend from the cap and seat in a groove on the base.
FIGS. 14A-14E show several exemplary embodiments of a retaining member which may be placed intraoperatively, so as to hold or retain the doors within the base. All of these embodiments include a hole feature to facilitate manipulation of the member. One embodiment 400 is a conventional retaining ring, as will be well familiar to those skilled in the art and this is seen in FIG. 14A . In FIG. 14B , retaining member 410 includes a member 415 to increase the security of placement of the retention member. Additional security may be desirable if mounting features for a cap or intraoperative instruments are added to the retention feature. In FIG. 14C , the retaining member 420 occupies half, more or less, of the annular groove, so as to generate less interference with a medical lead placed in the lumen of the base. In FIGS. 14D and 14E the ends of retaining members 430 and 440 interface with a groove, such as 41 of FIG. 13C , but the body of these retaining members cross through the lumen of the base. Such disposition of the body of the retaining member keeps the groove free to accept other attachments. Retaining member 430 passes straight across, while retaining member 440 curves away from the center, so that it is clear of the center during placement. The depictions of retaining members 430 and 440 also include material 450 above the plane of the annular groove. Such material may be arranged so as to strengthen or stiffen the retaining member, or to interface with other parts.
FIGS. 15A-15D show an embodiment where retaining member 460 has pins 220 extending in such a way that they could snap into the cap 200 and thereby attach it to the base 10 . FIG. 15A is a perspective view of the anchor base 10 with retaining member 460 and cap 200 assembled together. FIG. 15B shows cap 200 and FIG. 15C shows the retaining member 460 . Anchor base 10 is seen in FIG. 15D . FIG. 16 is a perspective view of anchor base 10 with the doors 110 and 120 and retaining member 440 assembled together. The retaining member 440 scats into an annular groove 41 , but its body is within the center of the base, leaving much of the groove 41 clear.
While the exemplary embodiments have been described in some detail for clarity of understanding and by way of example, a variety of additional modifications, adaptations and changes may be clear to those of skill in the art. Hence, the scope of the present invention is limited solely by the appended claims. | An apparatus for securing an implantable lead within tissue of a patient includes a base adapted to be secured to a patient's skull adjacent a craniotomy. The base has an upper surface and a lower surface with a central passage therebetween. The central passage is adapted to receive the implantable lead therethrough. The apparatus also has a cover that is releasably coupled to the base so as to substantially cover the central passage and capture the implantable lead therebetween. A first rotating member is also coupled with the base and the first member is rotationally movable so as to meet and engage the implantable lead at a plurality of positions within the central passage. | 0 |
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