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| Number | Title | Issue Date |
| 6986651 | Pump priming apparatus A pump priming apparatus including a housing through which fluid object material may be urged to flow, the housing including an intake portion and a pumping portion downstream from the intake portion. The apparatus further includes a piston assembly carried for reci... | 01/17/2006 |
| 6477940 | High-pressure piston cylinder unit The invention relates to a high-pressure piston cylinder unit, especially an injection pump or an injection valve for an internal combustion engine, and to a method for producing one such high-pressure piston cylinder unit. The high-pressure piston cylind... | 11/12/2002 |
| 6220772 | Fluid-dispensing and refilling system for a power toothbrush A pump used in a power toothbrush for fluid delivery to the bristles. The pump moves fluid provided to it to a dispensing valve located in the brushhead. The pump includes a pump chamber with a piston ball located therein. The piston ball moves within the... | 04/24/2001 |
| 6200103 | Gas lift plunger having grooves with increased lift A plunger in a plunger lift system in an oil and gas well includes circumferential recessed surfaces that define grooves spaced along the plunger body. A curved convex surface or radius is formed between the lower extent of each recessed surface and the p... | 03/13/2001 |
| 6199822 | Fluid-operated actuator A fluid-operated actuator (10) particularly for use in diesel-engined vehicles has a housing (12) defining a cylinder (14) having a cylinder wall (16) extending about a longitudinal axis (18). A piston (20) is arranged for reciprocal motion in the cylinde... | 03/13/2001 |
| 5967017 | Rotational displacement apparatus with ultra-low torque and high thrust load capability An improved rotational displacement apparatus is provided for measuring accurately the twist induced in an extension-twist coupled specimen in response to application of an axial load. The apparatus has an internal cylinder within which a piston rides. A ... | 10/19/1999 |
| 5946912 | Oil return loop of a hydraulic cylinder An oil return loop of a hydraulic cylinder which includes a plurality of equiangularly spaced V-shaped oil return grooves at the inside wall of an inner cylinder of the hydraulic cylinder for guiding saturated hydraulic oil to the outer cylinder of the hy... | 09/07/1999 |
| 5680988 | Axial force indentation or protrusion for a reciprocating piston/barrel assembly A reciprocating piston/barrel assembly, through which a fluid is capable of flowing, includes a piston having a pressure face separated from a downstream face by a side surface. A barrel has an interior wall surface defining a bore that is sized to slidab... | 10/28/1997 |
| 5660398 | Hydraulic sealing device In a sealing device, a crank-shaped oil channel is defined in an abutment of a sealing ring for sealing between a shaft member and a housing which surrounds the shaft member and is rotatable relative the shaft member. The crank-shaped oil channel is compr... | 08/26/1997 |
| 5440968 | Variable force cylinder device A variable force cylinder device with a piston reciprocated by a pressurized fluid in a cylinder chamber, in which the piston has a large-diameter portion and a small-diameter portion, the cylinder chamber has a large-bore portion corresponding to the lar... | 08/15/1995 |
| 5385456 | Pump for hot chamber die casting of corrosive light alloys A pump for the hot chamber die casting of corrosive light alloys including a body (2) wherein a cavity (3) is formed in which a piston (4) vertically reciprocates and on whose side wall (5) an opening (11) for the introduction of the molten alloy (1) and ... | 01/31/1995 |
| 5267838 | Severe service compressor system A severe service compressor for the reliable compression of dirty gasses using compressors with seals cooled by the hydraulic fluids doing the work of compression and seals isolated from the high temperatures of the compressed gasses by piston rings which... | 12/07/1993 |
| 5244363 | Low blow-by compressor A low blow-by compressor has a piston with at least one first ring disposed at the top end thereof and at least one second ring disposed at the bottom end thereof. A port is formed in the cylinder such that the port is above the second rings when the pist... | 09/14/1993 |
| 5222879 | Contact-less seal and method for making same A contact-less seal apparatus including a first surface and a closely adjacent second surface with a space defined therebetween. A high pressure fluid region exists on a first side of the space. A low pressure fluid region exists on a second side of the s... | 06/29/1993 |
| 5217245 | Switchable roll-stabilizer bar Vehicle suspension apparatus operating between the sprung and unsprung masses of a vehicle includes a pendular anti-roll bar connected to the vehicle, and a pair of links which connect the bar to the wheels. One and the other link, respectively, is extens... | 06/08/1993 |
| 5205200 | Hydraulic booster device for linear actuator A linear actuator used in moving, for example, gate valves, sluice gates and the like, wherein an increased thrust is required during initial movement. The present invention includes, as part of the linear actuator, a novel booster piston movably disposed... | 04/27/1993 |
| 5195320 | Piston-cylinder assembly particularly useful in stirling cycle machines A piston-cylinder assembly in which the piston includes two piston heads connected together in spaced relation by a stem and cooperable with two portions of the cylinder, dividing the cylinder into a working chamber on one side of the first piston head be... | 03/23/1993 |
| 5161822 | Tilt correction system The invention concerns a tilt correction system with at least one pair of cylinder and piston assemblies which are hydraulically operated. The extent of tilt correction is limited by grooves internal to the cylinders of the assemblies which short hydrauli... | 11/10/1992 |
| 5140905 | Stabilizing gas bearing in free piston machines In a free piston engine, to reduce dynamic loads on the reciprocating elements caused by a time varying pressure gradient across the gas bearing and close clearance seals provided therein, drain galleries are incorporated at the ends of the gas bearings t... | 08/25/1992 |
| 5050485 | Cushioning of piston sidethrust in gas lubricated engine Gas cushions are maintained between a piston and a cylinder of a gas lubricated reciprocating engine which are effective in retarding the approach of the piston to the cylinder wall under the thrust of side forces from the connecting rod. The cushion are ... | 09/24/1991 |
| 5031504 | Hydraulic jack with a system for checking the position of the piston In order to check the operation of high-voltage electric circuit-breakers, proximity detectors are housed in through-bores pierced in the wall of the hydraulic jack cylinder, the through-bores being disposed in spaced relation over a distance correspondin... | 07/16/1991 |
| 5032063 | Precision fluid pump Hydraulic fluid is replenished in a pulsator chamber of a fluid driven pulsator pump by having the power plunger in an upstanding bore with spaced seals. The power plunger is withdrawn upon each stroke vertically upward. As it is withdrawn past seals, any... | 07/16/1991 |
| 5009000 | Method for making sucker rod oil well pump A method of hardening a sucker rod well pump has a step of forming a boronized case on the plunger. Then the plunger is heated and quenched to form a hardened steel supporting layer. A chromium case is formed on the barrel.... | 04/23/1991 |
| 4998460 | Piston engine A piston engine comprising a piston movable in a recriprocating manner in a cylinder, while during operation a wedge-shaped gap is present between piston and cylinder. The piston divides the cylinder into a first chamber and a second chamber, which commun... | 03/12/1991 |
| 4981426 | Clamping mechanism in an injection molding machine A clamping mechanism which includes a cylinder and a piston. The diameter of the piston is less than the internal diameter of a rear chamber of the cylinder such that fluid flows around the piston when the piston moves from an open position to an intermed... | 01/01/1991 |
| 4969807 | Gas compressor with buffer spaces A gas compressor for use in a gas refrigerator includes a compression space having a volume varied with a positional shift of a piston when the latter reciprocates in a cylinder, a first buffer space communicating with the compression space in one directi... | 11/13/1990 |
| 4961372 | Closing mechanism for an injection molding machine A closing mechanism of an injection molding machine has a piston-cylinder unit to be pressurized hydraulically. Two partial strokes can be carried out in the unit, of which the first can be run through faster than the second. A displacement tube (7) exten... | 10/09/1990 |
| 4911618 | Cryocompressor with a self-centering piston A cryocompressor includes a check valve arranged in a circuit connecting a compression chamber defined by a piston disposed in a cylinder with an annular gap small enough to provide an expected sealing effect to a buffer chamber also defined by the piston... | 03/27/1990 |
| 4889039 | Gas compressor with labyrinth sealing and active magnetic bearings The invention, a high-pressure, reciprocating, gas compressor, employs labyrinths to create gas sealing, annular, air dams between the piston and cylinder bore, and piston rod and an aperture in an end wall or closure of the cylinder through which the rod... | 12/26/1989 |
| 4873913 | Dry roughing pump having a gas film bearing The present invention relates to a cryopump having a gas bearing formed in a clearance seal between a piston and a cylinder. The gas bearing is formed by forcing pressurized gas from a gas plenum through orifices to the clearance seal.... | 10/17/1989 |
| 4846051 | Uncooled oilless internal combustion engine having uniform gas squeeze film lubrication An apparatus for providing a gas phase film lubrication between a reciprocal piston and a cylinder of an uncooled oilless internal combustion engine; the piston is effective to drive a rotary crankshaft in response to an expanding gas charge. The apparatu... | 07/11/1989 |
| 4799421 | Hydrodynamic spiral-grooved journal bearing for electromagnetically rotated and reciprocated compressor piston A free-piston Stirling machine has a piston which can reciprocate and also rotate within a cylinder and which is supported and centered in the cylinder by a grooved dynamic bearing, the piston having two end faces which are acted upon during operation by ... | 01/24/1989 |
| 4776260 | Constant pressure pump An improved pump is provided for pumping non-lubricating fluids at extremely high pressure while reducing galling and wear on components such as pistons and cylinders. The reduction in component wear and galling is achieved by modifying the piston-cylinde... | 10/11/1988 |
| 4767290 | Fluid pump A self-priming pistonless lift pump has a first elongate tubular cylinder within which a second elongated tubular cylinder is loosely contained and freely slidable, the respective cylinders having inlet valves at their lower ends, and at their upper ends ... | 08/30/1988 |
| 4762474 | Pump having reciprocating pipe and slidably supported hollow body A bore hole pump which eliminates the need for a piston sealingly engaging with the walls of the pump body. The pump comprises a hollow body closed at its lower end by a non-return inlet valve and slidably and sealingly supporting at its upper end, via a ... | 08/09/1988 |
| 4711153 | Seal This invention provides a seal mechanism between two mating surfaces by means of a progressively, but not necessarily uniformly, decreasing clearance gap between said two surfaces for the flow of leakage of liquid and which gap may change as a function of... | 12/08/1987 |
| 4627798 | Apparatus for circulating cleaning fluid through a cooling system A single cylinder pump for circulating cleaning fluids through a radiator or like cooling system applies positive and negative pressure to the fluid to create a pulsating agitation of the fluid through the radiator through the use of a thin washer-like pl... | 12/09/1986 |
| 4627795 | Piston assembly for a compressor or the like A tandem piston arrangement for a compressor, especially for a dry-running compressor for the high pressure compression of gases such as oxygen, has one piston of the common rod form as a guide piston with piston and guide rings in engagement with the res... | 12/09/1986 |
| 4574834 | Passage means for hydraulic unit Passage means is provided for a hydraulic unit, in particular, a hydraulic unit including a plunger slidably fitted in a housing, a chamber formed with the housing and having a wall surface against which the plunger may abut, and a flow path opening into ... | 03/11/1986 |
| 4502843 | Valveless free plunger and system for well pumping A rugged lightweight valveless plunger (38) is provided for use in a well pumping system of the free plunger type. The plunger (38) comprises an elongated cylindrical integral aluminum body (42) having a rigid sealing section (44) formed by a plurality of... | 03/05/1985 |