Abstract: The subject application relates to a cupseal for a compressor and method for preparing the same. Systems and methods are disclosed that include providing an annular seal for a compressor. The annular seal includes a substantially planar first portion, a first angled portion extending at an angle from the substantially planar first portion, and a second angled portion extending radially at an angle from the first angled portion. The annular seal is formed from a fluorinated polymer and includes at least one additive or filler. The annular seal exhibits reduced wear and an increased lifespan.

Abstract: The present disclosure relates to a pumping assembly, a piston pump and a water flosser. The pumping assembly includes: a cylinder, at least two chambers with different inner diameters being provided in the cylinder; a piston mechanism successively extending through the at least two chambers, the piston mechanism being in slidable cooperation with walls of the chambers, and a gap being formed between a sidewall of part of the piston mechanism and the walls of the chambers; and a drive mechanism connected to the piston mechanism, the drive mechanism being configured to drive the piston mechanism to move.

Abstract: A packing assembly for a pump fluid end comprising: a packing screw; a packing carrier; and a packing, wherein the packing screw, the packing carrier, and the packing are each cylindrical with a width measured along a central axis thereof that is less than a minimum spacing distance of a pump comprising the pump fluid end and a pump power end, wherein the pump fluid end comprises a reciprocating element bore in which a reciprocating element can be reciprocated via the pump power end via connection of the reciprocating element to a reciprocating element adapter coupled with a pushrod and crankshaft of the pump power end, wherein the minimum spacing distance is an axial distance measured along the central axis between a back of the pump fluid end and a front end of the reciprocating element adapter when the crankshaft of the pump power end is at top dead center.

Abstract: A hydraulic fluid cylinder is equipped with a cylinder tube, a piston unit, and a piston rod. The piston unit has a gasket and a piston body comprising a plurality of members and provided with a gasket-mounting groove. The piston body has a first piston member which projects to the outside from the piston rod, and also has a second piston member positioned so as to be adjacent to the first piston member. The gasket-mounting groove is formed from a combination of at least two members.

Abstract: A brake piston includes a piston pocket. The piston pocket receives a nut that is axially moveable along a center axis. The nut is restricted from rotating within the piston pocket when a torque due to a frictional engagement between a nut seal and an inner pocket wall, one or more projections, or both is greater than an it torque at the nut. The nut is rotatable within the piston pocket when a torque due to the frictional engagement between the nut seal and the inner pocket wall, the one or more projections or both is less than the input torque at the nut and is less than the torque due to the frictional engagement between the piston and the piston seal.

Abstract: Pistons for a syringe and syringe systems are disclosed. The pistons may include a base with a first end, a second end opposite the first end, and a side portion extending between the first end and the second end. The piston may also include at least one engagement portion extending around the circumference of the side portion of the base. Another embodiment of the plunger head may include a proximal end, a distal end opposite the proximal end, and an intermediate portion connecting the proximal end and the distal end. The intermediate portion is tapered from the proximal end to the distal end. The syringe system includes a piston and a plunger rod. The plunger rod may include a first end and a second end with the first end pressingly contacting the distal end of the piston.

Abstract: A reciprocating compressor including an oscillation-type piston mechanism is provided with a piston ring which is mounted in a piston ring groove to seal a space between a piston and a cylinder. A ring groove other than the piston ring groove is provided at an outer periphery of the piston on a side away from the piston ring groove and closer to a crank shaft. A guide ring, which is inhibited from radial movement and shaped like a skirt opened toward the crank shaft, is mounted in the ring groove. Thus, the oscillation-type reciprocating compressor is adapted to maintain long-term durability even under high-pressure compression condition and to prevent heat propagation to a large end portion.

Abstract: A reciprocating pump including a piston is disclosed. In some embodiments, the piston includes an annular hub, a flexible sealing element coupled to an outer surface of the hub, and a sleeve seated on the outer surface of the hub adjacent the sealing element. The sleeve is axially moveable relative to the hub to compress the sealing element. The sealing element includes a lip, which is displaced radially outward when the sleeve compresses the sealing element.

Abstract: A swing-type reciprocative compressor is capable of maintaining long durability and preventing propagation of heat to the large end portion of a piston, even under high-compression. In the reciprocative compressor having a swing-type piston mechanism, a piston ring is attached to a piston ring groove to seal between a piston and a cylinder. A ring groove is provided separately from the piston ring groove on the outer circumferential side of the piston and on the crankshaft side of the piston ring groove. A guide ring restricted from moving in a radial direction and shaped like a skirt opening toward the crankshaft side is provided in the ring groove.

Abstract: A high pressure piston for use within a liner sleeve of a reciprocating pump comprises a dual-durometer elastomeric seal having first and second coaxial seal sections and, in certain embodiments, a circumferential bearing ring. Interactions of the seal components, including seal elastomers, result in stress redistribution within the seal which maintains sealing preload, with corresponding improved extrusion resistance and seal durability. When a bearing ring is present, a pump's pressure stroke causes at least a portion of the bearing ring to elastically expand radially to narrow or close the extrusion gap, thus tending to block elastomer extrusion by establishing sliding contact between the bearing ring's external surface and the liner. On the pump's return stroke the slightly wider extrusion gap allows cooling water directed generally toward the proximal flange of the piston hub to better cleanse, as well as cool, the liner wall.

Abstract: To prevent effects of small amplitude oscillations caused by pressure fluctuation, eccentric attachment of a cancel plate and biased load application of a return spring, and to achieve a long service life of the inner peripheral seal portion, a BPS (1) with a piston member (20) moving in an axial direction inside a cylinder (10) and defining a compression chamber (M) together with the cylinder (10) and a cancel plate (30) opposing to a bottom portion (11) of the cylinder (10) beyond the piston member (20) is provided with an inner peripheral seal portion (50) with a seal lip (52) slidably contacting an inner peripheral tube portion (13) of the cylinder (10) and a fitting portion (53) fitted to the inner peripheral tube portion (13) in an inner peripheral end portion (35) of the cancel plate (30).

Abstract: A device for sealing a hydraulic piston in a hydraulic cylinder includes a hydraulic piston defining a fluid side and an air side and having at least one sealing groove defining at least one sealing groove side wall and a sealing groove base. A lip seal is inserted into the sealing groove and comprises a sealing lip facing the fluid side and a seal back facing the air side. The hydraulic piston has means for improving sealing action of the lip seal comprising a shaping of the sealing groove on at least one of the at least one sealing groove side wall and/or the sealing groove base.

Abstract: Pumping cartridges useful for medical and surgical pumping and infusion procedures. In one aspect, a series of pumping cartridges include cylinders and pistons which have a sealing component including a circumferential, flared sealing flange and can be configured to enable the pumping cartridge to generate high liquid pumping pressures. Many of the pumping cartridges can be configured to be detachable from a pump drive unit and disposable after a single use. Some pistons include or at least partially form a valve and/or are relatively movable with respect to a connected piston rod. Valves include a valve seat and a movable sealing element able to create a seal capable of withstanding differences in fluid pressures thereacross of at least about 1,000 psi. The movable sealing element is concave in shape, and may be curved for improved sealing performance. Methods for pumping or infusing a liquid for delivery to the body of a patient or a surgical or medical instrument.

Abstract: A reciprocating pump including a piston is disclosed. In some embodiments, the piston includes an annular hub, a flexible sealing element coupled to an outer surface of the hub, and a sleeve seated on the outer surface of the hub adjacent the sealing element. The sleeve is axially moveable relative to the hub to compress the sealing element. The sealing element includes a lip, which is displaced radially outward when the sleeve compresses the sealing element.

Abstract: A sealing arrangement which is designed for a cylinder-piston arrangement of a reciprocating piston vacuum pump for sealing a gap between a cylinder wall and a piston displaceable in the cylinder, includes at least one L-shaped annular seal having one of its leg secured on the piston for providing a static sealing, and its another free leg adjoining the cylinder wall for providing a dynamic sealing, and an annular guide member arranged on the piston between the piston and the cylinder on a side of the seal remote from a compression chamber of the pump.

Abstract: A piston with a built-in seal comprises a piston body (121) formed of a metal press-formed part and axially movably disposed in a clutch cylinder (110) and seal lips (122, 123) formed integrally with the piston body (121). A through tubular guide projection (124) is formed on the piston body (121). A return spring (150) for biasing the piston body (121) toward the pressurizing chamber (A) side is held on the guide projection (124). Since the press-formed through tubular guide projection (124) is higher in projecting height than the bottomed tubular one, the length over which the return spring (150) is held is longer. A pressurizing chamber (A) is prevented from being opened by the guide projection (124).

Abstract: The present invention provides a piston pump for liquid in which a sump is defined in a chamber into which sump liquid in the chamber flows due to gravity. A passageway leads from an outlet of the sump out of the chamber to a dispensing outlet. The dispensing outlet is at a height below the height of the sump outlet and fluid to exit the sump flows from the sump outlet upwardly in a first portion of the passageway to a height above the sump outlet then downwardly to the dispensing outlet. The chamber and its sump is defined between a piston chamber-forming member defining the chamber to be downwardly opening and a piston forming element axially slidable in the chamber.

Abstract: A packing stack for a reciprocating piston pump is formed of alternating V's of UHMWPE and either a polyurethane thermoplastic elastomer or an olefinic thermoplastic elastomer.

Abstract: A lip ring is attached to a piston so as to be rotatable relative to the piston in a circumferential direction, and a seal portion is provided between a ring attachment groove of the piston and an attachment portion of the lip ring. During a suction stroke, the lip ring can be rotated in a circumferential direction of the piston, thus distributing wear around the entire periphery of a lip portion of the lip ring. During a compression stroke, leakage of air from a compression chamber can be prevented by means of the seal portion provided between the ring attachment groove and the lip ring.

Abstract: A high pressure piston for use within a liner for a reciprocating pump comprises an elastomeric seal and an annular bearing ring. During the pump's pressure stroke at least a portion of the bearing ring elastically expands radially to narrow or close the extrusion gap, thus tending to block elastomer extrusion and establish sliding contact between the bearing ring's outer surface and the liner. An extrusion control groove located radially inward from the peripheral bearing ring contact surface of certain embodiments also tends to block elastomer extrusion. Under reduced pressure on the pump's return stroke, the bearing ring elastically contracts radially, slightly widening the extrusion gap. On the pump's return stroke the slightly wider extrusion gap allows cooling water directed generally toward the proximal flange of the piston hub to better cleanse, as well as cool, the liner wall.

Abstract: A free piston device which is particularly applicable for use with a linear motor for providing acoustic energy to a cryocooler for generating refrigeration at cryogenic temperatures which comprises a time varying clearance seal to counteract piston drift.

Abstract: A high pressure piston for use within a liner for a reciprocating pump comprises an elastomeric seal and a metallic annular bearing ring having relatively high heat conductivity compared to the liner and seal. During the pump's pressure stroke a portion of the bearing ring elastically expands radially to narrow or close the extrusion gap. Narrowing the gap decreases the tendency for extrusion of piston seal elastomeric material, while closing the gap tends to block elastomer extrusion and establish sliding contact between the bearing ring and the liner. Sliding contact between the bearing ring and liner prevents portions of the piston hub (e.g., a transverse flange) from contacting the liner and damaging it. The heat-conductive bearing ring improves scavenging of frictional heat near the extrusion gap, extending the service life of piston seal elastomer while reducing bearing ring and liner wear.

Abstract: A piston and ring assembly for a compressor that may be used in a vehicle air conditioning system. The assembly comprises a piston and a ring located within a cylinder bore. The ring has a frustoconical shape and the piston has a complementary frustoconical groove. The ring is a parallelogram in cross-section.

Abstract: A plunger for being inserted in a tubular barrel in an axially movable manner includes a plunger body having a distal end positioned within the barrel and a proximal end positioned outside of the barrel, and a seal member disposed on the distal end of the plunger body. The seal member has a base portion extending from the plunger body towards the distal end of the barrel, and a flange portion radially outwardly extending from the base portion and having a peripheral edge contacting an inner circumference of the barrel so as to define an accommodation space within the barrel.

Abstract: The present invention is directed to a master cylinder provided with an annular seal member (S1) having an annular groove of U-shaped cross section formed on its one end face, and a substantially annular seal retainer (30) for restricting at least axial movement of the seal member, and including a substantially annular lifted wall portion (31) formed to extend axially into the U-shaped annular groove of the seal member, and a substantially annular step portion (32) formed on an inner periphery of the lifted wall portion, for contacting an open end face of the seal member. The seal retainer is reduced in diameter by radial pressing force produced when it is received in a cylinder bore (1), and restored when the pressing force is released. The seal member is placed in an annular hold groove (1d), and the seal retainer is received from an open end of the cylinder bore to be placed in an annular transfer groove (1b), with the seal retainer reduced in diameter.

Abstract: A reciprocating piston compressor for a gaseous medium is provided having a reduced structural height. The compressor is especially for a level control system in a motor vehicle. The maximum pivot angle of the piston ring longitudinal axis relative to the longitudinal axis of the cylinder running path is smaller during the upward movement of the piston than for the downward movement of the piston. The longitudinal axis of the cylinder running path is offset relative to the first spatial axis.

Abstract: A gas cylinder of the present invention comprises a housing having a tube, a front head and an rear end cap defining a chamber. A pair of ports are provided to allow for the input and exhaust of gas in the chamber. A piston is received in the chamber for axial movement within the chamber and separates the chamber into two cavities. A rod is operatively connected to the piston and extends forwardly from the piston, through a bore in the front head to exit the chamber through the front head. The rod is loosely or floatingly connected to the piston, to be movable relative the piston by a plate at an end of the rod which is trapped in a bore in a forward end of the piston. A piston seal is received in a groove in the piston to form a seal between the piston and the cylinder tube. The piston is flexible and changes shape due to pressure changes within the chamber. A rod seal is also provided between the rod and the front head bore.

Abstract: A reciprocating compressor (26) includes two pistons (56 and 58) driven in opposite directions in a piston chamber (54). As a piston is driven in the downstream, compression-stroke direction, pressure causes a piston ring (64 or 66) that seals against the piston-chamber wall to seal against the piston, too, and thereby prevent fluid flow from the piston's downstream side to its upstream side. When the piston is driven downstream, on the other hand, pressure keeps the piston ring spaced from the piston and thereby allows flow from the piston's upstream side to its downstream side. The piston rings thus act as check valves.

Abstract: A reciprocating pump or compressor has a piston head assembly in a cylinder having an inside surface. The piston head assembly has a piston hub and a piston seal. The piston hub has a flange. A piston seal formed of a first and a second resilient material, the second resilient material having a hardness less than the hardness of the first resilient material, is mounted on the piston hub. The first resilient material abuts the flange and covers an outer surface of the flange. The second resilient material is bonded to the first resilient material. The piston seal has an annular bulge in the second resilient material with a maximum diameter interior to the annular bulge larger than the diameter of the inside surface of the cylinder, forming a seal with the cylinder when compressed upon insertion of the piston head assembly into the cylinder.

Abstract: For the purpose of providing a thin pump designed to decrease the number of parts, the pump is provided with a rectangular parallelepiped cylinder (3) and a piston located inside of the cylinder, wherein the piston (4) reciprocates and oscillates in the cylinder (3) to vary capacity of the pump chamber (12) and to make the intake port (5) and the outlet port (6) open alternately, so that fluid is sucked from the intake port (5) into the pump chamber (12), compressed and discharged from the outlet port (6).

Abstract: The present invention is directed to a wobble piston and seal assembly for an oil free compressor. An upwardly directed curvature is provided on a piston surface which supports the seal. The curvature is located adjacent the perimeter of the surface to impart a slight dish shape to the surface. Preferably, the curvature has the same radius as the bend radius of the seal when the piston head is inserted into a cylinder. When the seal is initially clamped to the support surface, the seal is formed to take on the curvature of the support surface. Consequently, the seal is preformed into a shallow cup shape prior to final forming when the piston and seal assembly are inserted into a cylinder.

Abstract: Within a piston cylinder of a pneumatic engine, the system includes a piston proportioned for complemental travel within a piston cylinder, the piston having a radial compression surface and elements for effecting the axial reciprocation of the piston within the piston housing. The system further includes a piston seal including an element for securement to the compression surface of the piston and an integrally dependent resilient annular skirt normally biased inwardly toward a longitudinal system axis, the skirt, in combination with the securement elements, defining a radius of less than that from the system axis to interior walls of the cylinder during low pressure (return stroke) phases of a work cycle of the pneumatic engine and, during high pressure/compression stroke phases, defining a radius greater than that from the system axis to the inner wall of the cylinder.

Abstract: A connecting rod assembly for rocking piston compressors, diaphragm compressors and vacuum pumps is provided where the overall height of the connecting rod assembly is dependent only upon the overall height of the connecting rod structure and is not dependent upon the thickness of the diaphragm or the thickness of the retainer plate. The connecting rod includes a disk portion for supporting an annular diaphragm in the case of a diaphragm pump or a cup in the case of a rocking piston compressor or a vacuum pump. The connecting rod also includes a distal end section that extends upward through the annular diaphragm and through an annular retainer plate. The diaphragm or cup is sandwiched between the annular retainer plate and the disk portion of the connecting rod. The overall height of the assembly is determined by the distance between the end face of the disk portion of the connecting rod and the crank end of the connecting rod.

Abstract: A piston-type compressor has several cylinder bores, each of which receives a piston assembly. The piston assembly reciprocates between a top dead center and a botom dead center in each cylinder bores. The piston assembly includes a piston and a piston ring. A groove is formed at or about a top dead center of an outer peripheral surface of the piston, and having a flat bottom surface thereof. The piston ring, which has a truncated cone-shape and may be made of resin, is fitted into the groove. An external diameter of the piston ring is greater than that of the piston. The piston ring is disposed in the groove, such that the wider edge of the ring opens toward a bottom dead center of the piston and a narrower edge of the piston ring abuts the bottom surface of the groove.

Abstract: Within a piston cylinder of a pneumatic engine, the system includes a piston proportioned for complemental travel within a piston cylinder, the piston having a radial compression surface and elements for effecting the axial reciprocation of the piston within the piston housing. The system further includes a piston seal including an element for securement to the compression surface of the piston and an integrally dependent resilient annular skirt normally biased inwardly toward a longitudinal system axis, the skirt, in combination with the securement elements, defining a radius of less than that from the system axis to interior walls of the cylinder during low pressure (return stroke) phases of a work cycle of the pneumatic engine and, during high pressure/compression stroke phases, defining a radius greater than that from the system axis to the inner wall of the cylinder.

Abstract: An improved wobble piston and seal assembly for an oil free air compressor. The piston has a seal support surface which is provided with an upwardly directed curve adjacent its perimeter. A flat annular seal is secured to the piston to be supported by the support surface. The curve imparts a limited bend to the seal adjacent the perimeter of the piston. The piston and seal are then inserted into a cylinder which increases the bend to substantially 90°. The region of the bend in the seal adjacent the top of the piston is supported by the curved top to reduce flexing during operation at high air pressures. By preventing a reduction in the bend radius at high air pressures, stress in the seal at the bend is reduced, permitting use of a harder more durable seal material.

Abstract: A solar-powered reciprocating pump for submersible use in a well, such as a water well. The pump has a pumping section with a plunger therein. The pump also has a drive section with a rotating output shaft and a transmission section which converts the rotating output of the shaft into reciprocating motion of the plunger. In one embodiment, the transmission comprises a gear train. In a second embodiment, the transmission comprises a ball screw which is actuated by a reversible motor. In a third embodiment, the transmission comprises a reversible ball screw which provides reciprocating action in response to rotation of a shaft in a single direction. The pumping section comprises an outer case portion with a cylinder disposed therein such that an annular volume is defined therebetween. A system of flow passageways and inlet and outlet valves provide for pumping liquid into and out of the pump in response to movement of the plunger in both upward and downward directions.

Abstract: Within a piston cylinder of a pneumatic engine, the system includes a piston proportioned for complemental travel within a piston cylinder, the piston having a radial compression surface and elements for effecting the axial reciprocation of the piston within the piston housing. The system further includes a piston seal including an element for securement to the compression surface of the piston and an integrally dependent resilient annular skirt normally biased inwardly toward a longitudinal system axis, the skirt, in combination with the securement elements, defining a radius of less than that from the system axis to interior walls of the cylinder during low pressure (return stroke) phases of a work cycle of the pneumatic engine and, during high pressure/compression stroke phases, defining a radius greater than that from the system axis to the inner wall of the cylinder.

Abstract: A novel reciprocating pump for cryogenic fluids. The pump has a cylinder sleeve, head, intake valve, discharge valve, and a reciprocating piston including a mechanical spring energized seal having a generally U-shaped jacket and a helical spring in the bight of the U.

Abstract: An accumulator piston for an automatic transmission. The piston comprises two components, the first and second being cup elements welded together with their closed ends in abutting relation. The lower cup includes a curled back portion with a radial flange having an axially extending bi-directional oil seal thereon, and spaced apart recesses in the curled back portion to permit oil to flow therein. The upper cup includes a radial flange of reduced diameter compared to the lower cup flange. The flange also has a lip seal thereon. The piston is spring-loaded and moves up and down in a bore and counterbore in response to fluid flow on either side of the piston to absorb shifting shocks.

Abstract: A fluid valve system is provided for a variable stroke motor. The valve has a housing forming a cylinder, a first fluid input into the cylinder, a first fluid output out of the cylinder, a second fluid input into the cylinder, and a second fluid output out of the cylinder. Provided within the cylinder is a shaft provided with slots. As the shaft rotates into a first position, fluid communication between the first fluid input and the first fluid output is shut off, while fluid communication between the second fluid input and second fluid output is opened. As the shaft rotates to a second position, communication between the first fluid input and first fluid output is opened, while the communication between the second fluid input and the second fluid output is shut off. The device is preferably hooked up to a drive cylinder in fluid communication with the first fluid output and the second fluid input. A piston is provided within the drive cylinder.

Abstract: A piston head assembly for reciprocating in a cylinder is disclosed, the cylinder having an inside surface and the inside surface having an inside diameter, comprising: a piston head including a central portion and a flange, the flange having a diameter that is no more than 0.010 inches less than the inside diameter and an annular seal removably mounted on the flange, the seal including a lip and a heel, the lip having an uncompressed diameter that is at least 0.20 inches larger than the inside diameter and the heel being free of a separate retaining means. The seal can also be manufactured so as to be free of any annular depression in its outer surface.

Abstract: An improved wobble piston for an air compressor. The piston has a head integrally connected to a connecting rod. The connecting rod has a free end for connection to a rotating eccentric. The piston has cooling fins to provide cooling as the piston is reciprocated in a cylinder. The cooling fins extend from a piston cap secured to the piston head. The fins extend through cooperating slots formed in piston head.

Abstract: An improved structure for a reciprocating internal combustion engine or compressor piston fabricated from carbon-carbon composite materials is disclosed. An integral ring carbon-carbon composite piston, disclosed herein, reduces the need for piston rings and for small clearances by providing a small, flexible, integral component around the piston that allows for variation in clearance due to manufacturing tolerances, distortion due to pressure and thermal loads, and variation in thermal expansion differences between the piston and the cylinder liner.

Abstract: A piston seal has formed on one side of the piston body upon which oil pressure works are a tapered surface portion which extends in a direction away from a piston sliding wall and a parallel surface portion. A lip-like seal is formed of a seal base portion which is, in cross section, approximately triangular to fill a space defined between the tapered surface portion and the piston sliding wall, and a lip portion which is formed integrally with the seal base portion. Q indicates the exertion line of a force which presses the lip portion against the piston sliding wall. T is a normal line which extends from the tapered surface portion towards the piston sliding wall. In order to prevent the lines Q and T from intersecting with each other within the bore, the seal base portion is arranged to lie apart from the lip portion in relation to the axial direction of the bore.

Abstract: An external slave cylinder particularly suited for use in a hydraulic clutch release system for a motor vehicle. The cylinder includes a cylindrical body defining a bore, a piston slidably mounted in the bore, a seal positioned between the piston and the bore, a pushrod engaging the rear end of the piston and extending out of the bore, and a preload spring. The spring comprises a conical coil spring positioned exteriorly of the bore, bearing at the reduced diameter rear end thereof against the rear end of the pushrod, and bearing at the large diameter front end thereof against the rear end of the body in surrounding relation to the pushrod. The seal has a cup-shaped configuration and fits over a nose portion provided on the front end of the piston. The seal includes a peripheral lip portion sealingly engaging the bore and a base portion closing the area within the peripheral lip portion and seated against the front end of the piston.

Abstract: A venting piston ring is provided with ports extending partly through the ring outer surface which cooperate with the end edge of a cylinder wall to vent the cylinder volume while intermediate surface lands between ports maintain ring to cylinder contact and alignment.

Abstract: A seal for use with an annular piston which may be used in a hydraulic system for actuating disc brakes or clutches of drivetrain subassemblies. The seal may be used with a piston having a relatively large average diameter and a relatively small radial thickness, with the piston being disposed, and axially moveable, within an annular passage having a pair of generally cylindrical, opposing side walls. The seal is made of an elastomeric material and comprises first and second annular flange portions having a first end attached to the base portion and a second, free end. Each of the flange portions diverge away from the base portion so as to dispose the corresponding free end in sealing engagement with one of the passage sidewalls. The base portion of the seal is bonded to an end surface of the piston and the seal further includes a plurality of circumferentially spaced ribs interconnecting the first and second flange portions.

Abstract: A vacuum pump for removing air from containers includes a pump housing in the form of a conduit with an open end and a closed end. A piston in the form of a conduit, open at each end, is slidably mounted within the housing, and has an inside end within the housing and an outside end protruding from the housing. The outside end of the piston is adapted to fit over a valve secured to the container. A piston ring is provided substantially at the inside end of the piston. The piston ring is adapted to mate tightly with an interior surface of the housing, such that movement of the housing away from the outside end of the piston will draw a vacuum through the valve to remove air from the container through the valve. A system and method for removing air from containers is also disclosed.

Abstract: A piston for a shock absorber as may be used in an automobile comprises a piston body, and a piston ring which covers the outer periphery thereof. One end of the piston ring is formed as a bend, which is received in a first receiving groove formed in the piston body. The first receiving groove comprises opposing end faces which extend in a direction orthogonal to the axis of the piston body, and a bottom surface which connects together the both end faces. The tip of the bend is disposed in abutment against the corner defined by one of the end faces and the bottom surface. As compared with the prior arrangement in which the end face comprising the corner is formed as a tapered surface, the tip of the bend is less likely to be displaced radially outward, thus reducing the possibility that he bend may be disengaged from he first receiving groove.