Abstract: A vibration and noise free pump is disclosed. The pump includes a plurality of cylinders in radial arrangement about an axis. A piston is slidably supported in each of the cylinders. Each of the pistons has a vent opening in addition to a set of inlet openings to admit escape of liquid out of its piston inner chamber into a well with the piston in the compression stroke. With the provision of the vent opening, a surge pressure in each of the pistons has been reducedsed.

Abstract: An elongate tank for transport or for storage in bulk of semisolid and fluid materials, such as grease and oil. The tank has an outlet at one end thereof for discharging material contained therein, and has a generally cylindric interior surface. A generally cylindric piston is sized to slide in the tank and is movable in a direction toward the outlet thereby to place material in the tank through the outlet. The piston comprises a piston member and an elastic annular seal carried in a circumferential channel around the piston member. The seal has an annular base and an annular crown disposed radially outwardly of and joined to the base with a fluid chamber between the base and crown. The seal is expandable by introducing fluid into the fluid chamber.

Abstract: A high pressure die cylinder and manifold system including a plurality of die cylinders mounted on a manifold. Each die cylinder includes a cylinder body in which a piston rod and a piston is positioned for limited relative movement with respect to the cylinder body. A cup shaped piston sealing ring is mounted on the cylinder body for engagement with the piston rod and a cup shaped sealing ring is mounted on the piston for engagement with the cylinder body. A lubricant metering ring is mounted on the piston intermediate the sealing rings and the piston has a lubricant chamber that communicates with circumferentially spaced openings in the lubricant metering ring for delivering lubricant to the exterior of the sealing ring.

Abstract: The shock absorber comprises a strut, a sliding rod slidably mounted relative to the strut and co-operating therewith to define both a shock absorbing chamber and a raising chamber which is connected to a member for feeding it with raising liquid, a dip tube defining a lowering chamber and connected to a member for feeding it with a lowering liquid, and in which a lowering piston is disposed, which piston has one face in contact with the shock absorbing liquid, and an anti-crash tube mounted to slide relative to the sliding rod and including an energy-absorbing member.

Abstract: An articulated mechanism for use as an articulated arm of an industrial robot, for example, includes a plurality of arms interconnecting articulations having respective fluid pressure angular displacement motors for angularly displacing the arms relatively to each other. The motors have sidewalls forming working chambers, where an inner surface of the sidewall is exposed to working fluid pressure tending to bow the sidewall outward, and an outer surface of the sidewall has a plurality of counteracting pressure chambers which apply a counteracting pressure force against the sidewall to oppose the outward bowing force, the counteracting pressure force increasing in pressure surface area as the piston is displaced within the motor chamber.

Abstract: A force applicator comprises a ram operable by fluid under pressure. A pressure pad (7) is located between one movable part of the ram (3) and the load (9) and means are provided which enable relative movement to take place between the pressure pad and the ram in a direction at right angles to the direction of operation of the ram. The means may take the form of a fluid chamber (15) between the pressure pad and the ram or a disc of PTFE between them.

Abstract: The piston compressor exhibits at least one piston (7) which is supported to be freefloating and connected via a piston rod (6) to a crosshead (5). The piston rod slides in a guide bearing (8) next to the crosshead in a gland (11) next to the cylinder. A ring (15) of porous material is arranged on the piston rod (6) between the guide bearing (8) and the gland (11). The ring (15) exhibits a circumferential groove which is intended for receiving a tubular spring and the depth of which--measured from the outside transversely to the longitudinal axis (6') of the piston rod--is at least as great as the outer diameter of one turn of the tubular spring.

Abstract: 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 between it and the end wall of the cylinder, a drive chamber on the opposite side of the second piston head communicating with the drive, and an intermediate chamber between the working chamber and drive chamber. The first piston head defines a clearance seal with respect to the first portion of the cylinder, and the second portion of the cylinder guides the reciprocatory movements of the piston. The intermediate chamber includes a semi-permeable seal between the cylinder and piston, which seal is permeable by gas but impermeable by liquids, to thereby prevent the passage of liquid from the drive chamber through the intermediate chamber to the working chamber.

Abstract: A reciprocating piston is disclosed with variable compression height for internal combustion engines in particular. For structural simplification of the temperature-dependent change in the compression height of the reciprocating piston, a spring is provided which consists of a shape memory alloy and interacts with the pressure limiting valve. This permits temperature-dependent change in the compression height of the reciprocating piston exclusively by the pressure limiting valve so that structural simplification is achieved.

Abstract: A dual master cylinder (10) for the braking system of a motor vehicle comprising a bore (18), a primary portion and a secondary portion (14), in which the secondary piston (44) of the secondary portion comprises an outer piston (65) slidable in the bore, and a central piston (78), the central piston including a main body (86) slidable in the bore and a secondary body (92) slidable in a piston bore (64) in the outer piston, the piston bore having a shoulder (72) engageable with a first abutment face (98) on the central piston to define a check valve (62), the piston bore providing a fluid passage (96,68) between the high pressure chamber (56) and the low pressure chamber (48) of the secondary portion, the check valve allowing hydraulic fluid to flow through the fluid passage during a rest mode or a release mode of the dual master cylinder, but preventing such flow during an apply mode.

Abstract: 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 to isolate the same, and circumferentially spaced grooves are incorporated in the close clearance seal region.

Abstract: Cylinders of the type used in fluid power systems are cushioned by a floating spear. The reciprocating piston is centrally bored to receive the spear. Accordingly, the spear and piston are movable independent of each other. A blind axial bore is formed in opposite ends of the spear and one or more diametrically extending bores are also formed in the spear in open fluid communication with those axial bores. Thus, when the spear enters the cushion cavity, the piston continues its motion and progressively blocks off the diametrically extending bores. Air in the cylinder cavity escapes into the atmosphere through the cushion cavity, but is constrained to enter the spear through one or more of the diametrically extending bores and hence through an axially extending blind bore. The length of the spear is variable, as is the length and diameter of the blind bore and the number, diameter, and spacing of the diametrically extending bores. Thus, the deceleration of the piston is programmable.

Abstract: A reciprocating type fluid delivery pump has a driving motor, plungers for driving two pump heads, respectively, and a converting mechanism for converting the rotational motion of the driving motor into a reciprocating motion of each plunger. The converting mechanism includes a cam having such a configuration that, when the driving motor is rotated at constant velocity, the delivery flow rate during the delivery starting period of each of the plungers is in excess of that during the other periods of the cycle. The speed of rotation of the driving motor is reduced during the excess delivery period according to need. Thus, the load on the driving motor is reduced and it is therefore possible to employ a driving motor having a relatively low output. The delivery pump also includes a rinsing chamber for each plunger for allowing pressurized fluid to pass therethrough. The rinse chamber includes a rinse pump which uses the reciprocal movement of the pump piston for the rinse mechanism.

Abstract: A piston seal device of pneumatic cylinder which satisfies the required tightness of a seal as well as the required lubrication characteristics for a piston movement is disclosed. The piston seal device for maintining different pressures acting on each side of the piston of pneumatic cylinder comprises slide rings located on peripheries of both sides of piston, a seal ring located at the outer part of pressure room formed along the periphery of central part of the piston and operated by pneumatic pressure of the pressure room, and a solenoid valve which operates in selection modes to supply the pressurized air into the pressure room. Slide rings are located with a proper distance at the peripheries of both sides of a piston installed in a pneumatic cylinder and at the center of a piston an expansionable seal is applied.

Abstract: The present invention relates to a sealing device provided between a piston rod of a Stirling cycle engine and a variable volume chamber. The sealing device is provided with an arrangement so as to equalize pressures between a seal chamber and the variable volume chamber of the Stirling cycle engine. By equalizing pressures between the respective spaces, an overpressure is prevented which would otherwise distort the seal and permit oil to be carried into the working volume of the Stirling cycle engine.

Abstract: A pneumatically operated hydraulically intensified rivet setting tool exhausts into the intensifier sleeve above the piston where the air expands and exits between the sleeve and the housing through a ring plenum and out an exit conduit.

Abstract: An electronically controlled actuator which compresses a fluid thereby storing potential energy as it transitions from a first to a second position is disclosed. The compressed fluid exerts a high force on the actuator and the potential energy is recovered in returning the actuator to the first position. A latching arrangement automatically locks the actuator shaft as it reaches the second position. The latching arrangement is selectively unlocked at the prescribed time to allow the stored potential energy to return the actuator to the first position.

Abstract: The invention relates to a piston having a variable compression height and two control chambers connected to each other through a hydraulic system. In order to achieve better cold-start and warm-up behavior, an oil discharge bore from the upper control chamber into the crankcase is closed by a control slide valve in the cold operating state of the engine. The blockage of the oil discharge produces a great compression height and therefore high compression. The control slide valve is connected to an expansible element which maintains it in this closed position when the engine is cold. As the engine warms up, the expansible element, due to its thermal expansion, pushes the control slide valve out of its closed position, so that the discharge of oil can occur progressively more unthrottled with rising temperature. In the warm operating state of the engine the control slide valve clears the oil discharge duct completely, and an unobstructed discharge of oil is ensured.

Abstract: A hydraulic cylinder apparatus is used by connecting an external pressure source with extension and contraction-side liquid chambers defined by a cylinder, a piston sliding in the cylinder and a piston rod integral with the piston. The apparatus includes seal members provided with the extension and contraction-side liquid chambers and formed to enable liquid to leak through clearances between the seal members and the parts disposed opposite to the seal members. Liquid leaked from the extension and contraction-side liquid chambers is received by a receiving chamber which is formed so as to change its volume with the movement of the piston rod.

Abstract: For a double-tube vibration damper which comprises an axially proceeding groove in the cylinder for by-passing the piston valves, a piston is provided which possesses a satisfactory sealing and guidance function in the cylinder. This is achieved in that the piston comprises a rigid piston ring arranged in a piston groove and acting as sealing ring against the cylindrical surface, while the piston comprises a second piston ring groove for the reception of a guide ring consisting of a piston ferrule. In this case at least one relief passage is provided which connects the second piston ring groove and/or the space situated between the piston ring grooves with the working chamber remote from the piston rod.

Abstract: A shaft alignment system for pumps which utilizes a clamp for holding a reciprocating shaft to a piston in an abutting relationship. The clamp can be loosened and retightened after the piston, which is attached to the reciprocating shaft, is inserted in a cylinder. Forces induced on the piston after insertion in the cylinder cause the piston and shaft to be realigned. Resecuring the reciprocating shaft assembly to the piston assembly causes the system to be precisely aligned in a transverse direction.

Abstract: A self-flushing fluid seal assembly is provided to prevent particle intrusion into the main seal around a slurry pump shaft. The assembly includes an annular tube concentrically disposed about the pump shaft and forming a chamber. The volume of the chamber is made variable by a plunger comprising an enlarged diameter portion of the pump shaft movable relative to the chamber during the power and return stroke of the pump. Flushing liquid is delivered to the chamber by means of a feed line extending through the shaft. A check valve provided in the feed line opens to allow the inward flow of flushing fluid from the feed line to the chamber as the chamber expands. Conversely, the check valve closes and a secondary shaft seal is provided to prevent the reverse flow of flushing fluid as the chamber contracts on the return stroke.

Abstract: A brake booster having a constant pressure chamber and a variable pressure chamber formed respectively at both front and rear sides of a power piston within a housing, characterized in that a hollow expansion body expansible axially of the power piston is disposed within the constant pressure chamber and one end of the hollow expansion body is secured fixedly to the housing while the other end of the expansion body is connected to a push rod so that the force magnifying ratio of the brake booster is varied by adjusting the internal pressure in the hollow expansion body.

Abstract: A seal assembly is arranged to contain leakage of hydraulic fluid passing between a wall opening and a penetrant rod portion passing through the opening. The seal assembly includes a sliding-seal member mounted on a portion of the rod for sliding movement toward and away from an abutment surface and a non-sliding flexible-seal member arranged between the body and the sliding-seal member. The body, flexible-seal member, sliding-seal member and rod define a sealed chamber into which such fluid will leak. The chamber communicates with a fluid reservoir through a oneway check valve. The sliding-seal and flexible-seal members are arranged in parallel with one another. In one embodiment, a spring urges the sliding-seal member to move toward an abutment surface provided on the rod. In another embodiment, movement of the sliding-seal member relative to the body is limited by facing abutment steps.

Abstract: A pressure relieved piston rod seal for piston-cylinder having tandem seals around the piston rod which are subject to failure when the pressure between the seals is greater than the pressure in the cylinder chamber. The piston rod seal of this invention solves this problem by providing a unidirectional seal between the end or low pressure rod seal and the cylinder chamber which relieves the pressure between the seals while sealing the chamber. The unidirectional seal includes a fluid passage which permits fluid flow into the cylinder chamber when the pressure between the seals is greater than the pressure in the cylinder chamber and seals the cylinder bore when the pressure in the chamber is greater than the pressure between the seals.

Abstract: The pump has a pumping chamber with a deflectable diaphragm member and fluid inlet and outlet passages. A deflectable valve flap is disposed across the fluid inlet passage and another flexible valve flap is disposed across the fluid outlet passage. Movement of the flexible valve flaps is responsive to movement of the flexible diaphragm member, reciprocation of which establishes alternate sequential suction and discharge conditions. An air chamber provided in the pump receives outside air through an air vent opening and also communicates with the pump discharge passage through a bleed hole when the outlet passage is closed by the outlet valve flap. The outlet valve flap is also deflectable to a position where it closes the bleed hole. Under this arrangement, continuous siphoning of fluid through the pump after the pump has been shut down is obviated.

Abstract: This invention relates to a pump arrangement (54) for use in a linear fluid operated device having a reciprocating piston (14) separating a first active fluid chamber (30) and a second chamber (32) which eliminates the problem associated with fluid leakage buildup developing in the second chamber. The pump arrangement (54) is connected to the reciprocating piston (14) and pumps leakage fluid present in the second chamber (32) from the second chamber (32) and into the first chamber (30) in response to a force of a preselected minimum magnitude being applied to the pump arrangement (54). Thus, the problems of inefficient linear fluid operated device operation, reduced piston stroke length, external fluid leakage, and erratic piston travel speed are eliminated. The pump arrangement (54) is particularly suited for use in a single acting linear hydraulic jack (12) such as used on a material handling vehicle.

Abstract: The compression ratio of an engine is controlled to optimize efficiency or performance, or both. The effective length of the piston is varied to change the compression ratio, by means of one of several piston configurations for adjusting the effective piston length as measured from the wrist pin. The piston length is hydraulically controlled, by hydraulic fluid introduced into a control chamber of the piston by a conduit connected to the piston and extending through the side of the engine. The conduit is designed to accommodate the reciprocal motion of the piston, and may be in a form of a flexible helix or other suitable configuration. Multiple hydraulic fluid channels may be provided in the conduit to permit circulation of the fluid or to permit the monitoring of critical parameters. The compression ratio is preferably controlled externally to the engine; valving and other controls linked to the hydraulic conduits extending from the engine may be linked to a computer.

Abstract: A compressible bellows surrounds a piston rod of the hydraulic cylinder of a hydraulic elevator. The lower end of the bellows surrounds a liquid receiving recess in the gland box of the cylinder and, when a sealing ring on the piston rod closes and compresses the bellows, the leaked hydraulic fluid is discharged from the recess, via a ball check valve, and a return tube to a sump.

Abstract: An improved valve actuator is provided for employment in environments such as subterranean wells where highly corrosive gases and fluids are contained in the well fluid which is normally pressurized and employed to operate the actuator. The bias element opposing the pressure induced movements of the piston unit of the actuator is disposed in an isolation chamber defined between two axially spaced, radial shoulders provided on the piston and having sealing engagement with the bore of the cylindrical wall, thus defining constant volume annular chamber that is isolated from the highly corrosive fluids and gases. The isolated chamber moves with the piston and thus does not provide fluid pressure opposition to the fluid pressure induced movement of the piston.

Abstract: The impeller bearings in a turbocharger on an internal combustion engine are supplied with a coolant, in the form of lubricating oil from the engine's crankcase, during post-shutdown coasting of the impeller. This coolant is supplied by an accumulator including a piston having an upstream side which is subjected to oil under pressure from the crankcase during engine operation to move the piston downstream for loading a spring affixed to the downstream side of the piston. Coolant leaking downstream of the piston is returned to the crankcase through a valve seat which is closed during engine operation by a valve extending from the downstream side of the piston.

Abstract: The machine tool provided with a machine frame adapted to be attachable to a stand, a pneumatic cylinder for reciprocating a quill on the machine frame, and a feed control device for controlling the forward moving speed of the quill comprising a hydraulic cylinder which is parallelly disposed to the quill and includes a piston assembly having a projecting portion engageable with the quill and a liquid tank. The quill is moved, until it is engaged with the projecting portion in the forward moving thereof, at a rapid feed speed and after the engagement at a controlled feed speed by the feed control device. The liquid tank has a pair of openings arranged such that either one of the two may constantly come under the liquid surface in the tank no matter in what posture the machine frame may be attached to the stand.

Abstract: A two part variable compression ratio (VCR) piston assembly having an outer member movable relative to an inner member to vary the compression ratio of an internal combustion engine and a hydraulic system utilizing oil from the lubrication system of the engine for automatically controlling the relative movement of the members to maintain a predetermined maximum combustion chamber pressure. A hydraulic circuit includes an upper and lower chamber which expand and contract conversely upon relative movement of the piston members and a system for supplying oil to the upper chamber and to the lower chamber via the upper chamber and for discharging the oil from the upper chamber in a manner which gradually changes the compression ratio of the piston until a predetermined maximum combustion chamber pressure has been achieved and which tends to maintain the maximum combustion chamber pressure after it has been achieved.

Abstract: The invention relates to a compressor of the type used in refrigeration systems. In these compressors the piston pin in the transversely extending piston bore is of lesser length than the diameter of the piston such that undesired chambers are formed at opposite ends of the pin. The stroke is normally of a length that the piston pin and these chambers intersect the lower edge of the cylinder. Gas trapped in these chambers expands rapidly with an undesired popping noise when fluid communication is established at the end of the down stroke between the chambers and the interior of the crankcase. Throttling passages are provided between these chambers and the interior of the crankcase to prevent pressure build-up in the chambers and the accompanying popping noise.

Abstract: A sealing device between a reciprocator and a stationary encircling housing comprises first and second rolling diaphragms at opposite ends of the reciprocator and exposed to higher and lower pressures, respectively, diaphragm-supporting liquid in first and second chambers in the respective diaphragms, and pumping means which, owing to the reciprocation, pumps liquid from the second chamber to the first. This means comprises an annular seal carried by the reciprocator, sliding on the housing and acting as a piston and as an inlet non-return valve, and another annular seal carried by the housing, sliding on the reciprocator and acting as an outlet non-return valve.

Abstract: A pneumatically buffered drive system is provided which quickly moves a movable member, such as a press safety curtain or press bolster, a predetermined length in three sequential speed stages to prevent maximum acceleration from occurring at the end of the predetermined length. The movable member is coupled to a differential pressure piston which is initially pressurized on only one side of the piston to initiate movement. After traversing approximately half the predetermined length both sides of the piston are pressurized to decelerate the piston during the member movement for approximately the next third of the predetermined length. The remaining length is traversed with the decelerating pressure being vented to positively finish the motion along the predetermined path. In vertical moving members having significant mass such as press safety curtains, a higher pressure is used to decelerate the piston than the pressure used to drive the piston.

Abstract: A two part variable compression ratio (VCR) piston assembly having an outer member movable relative to an inner member to vary the compression ratio of an internal combustion engine and a hydraulic system utilizing oil from the lubrication system of the engine for automatically controlling the relative movement of the members to maintain a predetermined maximum combustion chamber pressure. A hydraulic circuit includes an upper and a lower chamber which expands and contracts conversely upon relative movement of the piston members and a system for supplying oil to the upper chamber and to the lower chamber via the upper chamber and for discharging the oil from the upper chamber in a manner which gradually changes the compression ratio of the piston until a predetermined maximum combustion chamber pressure has been achieved and which tends to maintain the maximum combustion chamber pressure after it has been achieved.

Abstract: Disclosed is a leak retriever for the packing gland on oil well pumps. The leak retriever has a reservoir disposed about the packing gland to collect oil which leaks through the gland and an auxiliary pump which is mounted in the reservoir and connected to pump all oil collected back into the discharge line for the well. The auxiliary pump is mounted in the reservoir so that any leaks from the auxiliary pump are also collected by the reservoir, and is driven by a plate on the polish rod of the well pump driving apparatus. In the first form the reservoir is clamped onto the packing gland housing below the cap nut, and in the second form it is made integral with the cap nut.

Abstract: A method and apparatus are disclosed for preventing burnout of a fluid pump. The pump includes a pump casing having a pumping member disposed for movement therein. An outer casing is disposed about the pump casing so as to form a reservoir therebetween. Additionally, the pump casing is provided with a plurality of openings in order that pumped fluid may be recirculated between the interior of the pump casing and the reservoir. The openings are so constructed and arranged as to directly lubricate the pumping member as well as to insure continuous recirculation of the pumped fluid in the event the supply of fluid to be pumped should decrease.

Abstract: This invention relates to a hydropneumatic valve actuator comprising an outer cylindrical casing and an inner cylindrical casing both having closure means at each end. The inner cylindrical casing is positioned in said outer casing and is transversely spaced therefrom to define an elongated annular gas chamber. A piston slidably mounted in said inner casing has a piston rod extending axially from one end thereof through an axial bore in one of said closure means. The gas chamber as well as the portion of the inner casing between the piston and the other closure means, are adapted to be charged with gas under pressure and the portion of the inner casing between the piston and the closure means through which the piston rod extends is adapted to be charged with liquid.The piston is provided with a pair of spaced annular seals and means are provided to prevent gas leakage past one of the seals into the portion of the inner casing charged with oil under pressure and to sense leakage of oil past the other seal.