Abstract: Method, and associated system, computer program and use, of controlling working range of a pump bellows, including maximum limitations such as maximum retracting position and maximum extension position of the bellows, the method comprising the steps of: a) reading at least a first position of a bellows (6?, 6?) in a closed hydraulic loop volume using at least one position sensor (12?, 12?), g) transmitting a first position signal representing the first position to a control system, h) wherein the control system, based on the at least first position signal: c1) determines the position of the bellows (6?, 6?) represented by the at least first position signal, c2) compares the position of the bellows (6?, 6?) with a predetermined bellows position operating range, and c3) if the position is outside the predetermined bellows position operating range, instructs an oil management system valve (16?, 16?) allowing a dual acting pressure boosting liquid partition device (2) to recalibrate the hydraulic fluid volume in

Abstract: A diaphragm pump includes a pumping chamber, suction and pressure connections, a working chamber filled with a hydraulic fluid, a device for applying an oscillating pressure P1 to the hydraulic fluid, and a diaphragm separating the pumping chamber and the working chamber moveable between a pressure stroke position and a suction stroke position. A storage chamber accommodates hydraulic fluid at a pressure P2. The storage chamber and the working chamber are connected to each other by a valve having a closing part. The diaphragm cannot move too far beyond the pressure stroke position. The diaphragm is coupled to the closing part so that the valve is opened when the diaphragm moves from the pressure stroke position to a position that is farther from the suction stroke position than the pressure stroke position.

Abstract: A system for pressurizing a working fluid including a cylinder having an outlet through which the working fluid is exhausted at a discharge pressure and a plunger translatably disposed within the cylinder, the plunger including a first piston coupled thereto. In addition, the system includes a second piston disposed opposite the first piston, the second piston driven to reciprocate and a variable-volume chamber disposed between the first piston and the second piston, the variable-volume chamber substantially filled with a volume of hydraulic fluid. Further, the system includes a hydraulic system configured to adjust the volume of hydraulic fluid within the variable-volume chamber, whereby the discharge pressure is maintained substantially at a first predetermined level. Still further, the system includes a transducer coupled to each of the first piston and the second piston, wherein the transducer is configured to measure a relative position of the first piston and the second piston.

Abstract: Disclosed herein is a compressor in which oil retained in a hermetic case may be raised through an inner circumferential surface of a rotating shaft. The rotating shaft is provided with a hollow portion, and a fixation shaft with a spiral wing is inserted into the hollow portion to raise oil. Also, a spiral groove is formed on an outer circumferential surface of the rotating shaft to cause the raised oil to descend and lubricate the outer circumferential surface of the rotating shaft, and the hollow portion and the spiral groove are connected to each other via a guide passage.

Abstract: Detecting a failure mode of a fluid flow controller configured to control fluid flow between first and second chambers of a downhole positive displacement pump and a flow line, wherein the positive displacement pump comprises a piston moving in an axial reciprocating motion, and subsequently adjusting operation of the downhole positive displacement pump based on the detected failure mode such that the downhole positive displacement pump piston operates differently in different axial directions.

Abstract: The present invention relates to a submersible pump and a submersible pump system for pumping liquid to a marine structure, the pump being adapted to be located in a tube. The pump comprises an upper portion and a lower portion. The upper portion is adapted to be connected to means for suspending the pump in the tube. The pump has a vertical direction extending from the lower portion to the upper portion. The pump further comprises an inlet for allowing the liquid into the pump and an outlet for allowing the liquid out of the pump. The pump further comprises a sealing means located downstream of the inlet and the outlet in the vertical direction, the sealing means being adapted to seal against an inner surface of the tube. The invention further relates to an arrangement for hydraulic drive of the submersible pump and to a semi-submersible unit comprising the submersible pump system.

Abstract: The present invention relates to a pump device having a diaphragm pump head with two fluid delivery chambers, each fluid delivery chamber having a corresponding control chamber separated from the fluid delivery chamber by an associated diaphragm, a piston chamber in fluid communication with both fluid delivery chambers, and a double-acting piston assembly provided in the piston chamber and defining a single piston head that simultaneous acts upon both of the corresponding control chambers to drive the associated diaphragms.

Abstract: A valve arrangement for placing a supply of motive fluid in alternating communication with first and second motive fluid chambers. The valve arrangement includes a power valve including a supply chamber, a pilot chamber, and a shiftable member separating the supply chamber from the pilot chamber. The valve arrangement also includes a pilot valve actuable between an on condition in which the pilot valve generates a pilot signal that shifts the power valve, and an off condition in which the pilot valve does not generate the pilot signal. At least a portion of the pilot valve is exposed to motive fluid, and the portion of the pilot valve exposed to motive fluid includes surface areas giving rise to a net zero actuating force arising from pressure of the motive fluid. Because there is no biasing force on the pilot valve, the pilot valve is shifted between the on and off conditions without significant resistance.

Abstract: A device for difficult intervention in a closed enclosure, having an enclosure connected to the closed enclosure via a duct, a piston that can be moved by a motor, a geometry allowing a contact with the outside air when the piston occupies a certain position within the enclosure in order to generate a sudden release of pressure, and an outlet valve remaining closed when the piston increases the volume of the enclosure so as to cause the pressure reduction within the enclosures.

Abstract: A hydraulically driven pump includes a diaphragm, a piston, a transfer chamber, a fluid reservoir, and a valve spool. The transfer chamber is defined between the diaphragm and piston and is filled with a hydraulic fluid. The fluid reservoir is in fluid communication with the transfer chamber via at least one valve. The valve spool is configured to control fluid flow between the transfer chamber and the fluid reservoir. The valve spool is movable to open and close an opening into the at least one valve only when an overfill condition or an underfill condition exists in the transfer chamber. The valve spool is moveable along an axis that is non-coaxial with an axis of movement of the diaphragm.

Abstract: A diaphragm pump including, in a pump body, a hydraulic control chamber disposed between a piston for executing reciprocating motion and the diaphragm, the pump including elements for compensating leaks from the hydraulic chamber, the elements including a refilling duct opening out into the hydraulic chamber via a normally-closed compensation shutter that is driven into the open position by the diaphragm, wherein the above-mentioned compensation shutter being driven by the diaphragm pressing against a free end of a rod for controlling the shutter, the diaphragm being subjected to the force of a suction-assistance spring which co-operates with the above-mentioned shutter to return it to its closed position by pushing the free end of the control rod back towards the diaphragm, the spring co-operating with the shutter to form a moving assembly that is moved without being deformed by the diaphragm during suction overtravel.

Abstract: A hydraulically driven pump includes a diaphragm, a piston, a transfer chamber, a fluid reservoir, and a spool member. The transfer chamber is defined between the diaphragm and piston and is filled with a hydraulic fluid. The fluid reservoir is in fluid communication with the transfer chamber via at least one valve. The spool member is configured to control fluid flow between the transfer chamber and the fluid reservoir. The spool member is movable to open and close an opening into the at least one valve only when an overfill condition or an underfill condition exists in the transfer chamber.

Abstract: A diaphragm pump which overcomes the problem of diaphragm failure due to overfill of the oil transfer chamber. An overfill preventive element in the form of a mechanical stop, a fully closed coil spring, or a valve system, or alternatives are provided.

Abstract: A diaphragm pump which overcomes the problem of diaphragm failure due to overfill of the oil transfer chamber and the inability to self-prime. A notch is provided in the upper portion of the surface of the cylinder so that air can be forced back to the reservoir. In addition, the bias spring connected to the diaphragm and supported by the piston is made stiff with a spring constant that produces a bias pressure that can overcome abnormal suction pressures.

Abstract: A metering device that includes a housing defining a cylindrical chamber containing a reciprocating shuttle. The two opposed end parts of the chamber are interconnected by fluid flow ducts to a cylindrical valve bore. Contained with the valve is a rotary valve rod driven rotationally by a stepping motor. The valve rod has part cut away to form channels or recesses. In one rotational position of the valve rod a flow path is established from an inlet to one end of the chamber and a separate flow path is established from the other end of the chamber to an outlet. In an alternate orientation of the valve rod a flow path is formed from the inlet to the other end of the chamber and the first end of the chamber is connected to an outlet.

Abstract: An aircraft fluid delivery device (10) including a piston assembly (20), a pilot assembly (22), and a control assembly (24). The control assembly (24) includes non-contact proximity sensors (S1, S2) that sense the position of the piston (28) and a controller (80) that controls the pilot assembly (22), and thus the piston assembly (20), based on information received from the sensors (S1,S2). Specifically, the controller (80) energizes a solenoid (72) to cause fluid to flow through the pilot assembly (22) into a large portion of the piston chamber (30) during the compression stroke of the piston (28). When the solenoid (72) is deenergized during the return stroke of the piston (28), or when the delivery device is electrically turned off, an ejector (60) in the pilot assembly (22) generates a vacuum on the pressure side of the wide portion of the piston chamber (30).

Abstract: A high-pressure pump for pumping fuel, and includes a main unit for pumping the fuel, which unit is actuated by a secondary unit for pumping a working liquid. The secondary unit has a filling neck for filling a reservoir with working liquid. The filling neck is connected to the reservoir which is selectively plugged by a plug. The plug is provided with a plugging surface that mates with a plugging seat formed in the neck. The neck includes an area for containing an excess of working liquid overflowing from the reservoir. An overflow level extends into the neck above the seat. The plug moves in the neck in the presence of the overflow of working liquid, between a position of pre-plugging, in which the plugging surface is removed from the seat, and a position of plugging in which the plugging surface is in sealed contact with the seat.

Abstract: The present invention relates to a pumping device for delivering and metering fluids, in particular medical fluids such as dialysis fluids, with a piston unit having a driving device and a piston and with a membrane unit which has a membrane and a first chamber bordered by the membrane. The pumping device also has a hydraulic unit which has a space to accommodate a hydraulic fluid which is connected to the piston of the piston unit and to the first chamber of the membrane unit. The reliability of metering by such a pumping device is increased by providing a control unit for guaranteeing a predefinable metering rate and/or quantity and also providing a measuring device by means of which the axial position of the piston unit can be determined directly and which can be connected to the control unit.

Abstract: A valve arrangement including a valve housing (10) which includes an inlet port (11) and two outlet ports (12, 13) for fluid flowing through the housing. A valve element (15) is accommodated in a first valve space in the valve housing and movable between two end positions. The valve element includes two surfaces (16), each of which is adapted for co-action with a respective outlet port such as to close an associated outlet port in one and the other of the end positions of the valve element (15). A device (20 or 21 and 26, 47) for resetting the valve element between the positions. The valve element (15) is mounted on one end of a pivotal arm (18) and has the form of a valve plate or disc which includes valve-element surfaces (16) for alternate co-action with a respective outlet port (12, 13).

Abstract: A valve housing (10) includes an inlet port (11) and two outlet ports (12, 13) for fluid passing through the housing. A valve element (15) accommodated in the valve housing is moveable freely between two end positions and has two surfaces (16) each adapted to close a respective outlet port in one and the other of the two end positions of the valve element. The valve element further includes members (20, 22: 21, 22: 21, 26, 47; 26, 48; 26, 50; 26, 51-54) for resetting between the positions. A double-action pump includes two spaces or rooms that have valve-controlled inlets and outlets (39, 40; 29, 30) for drive fluid and pump-transported working fluid respectively. The spaces are divided into an operating chamber (28) and a working chamber (27) by partition walls (26, 36, 37) which are pistons or diaphragms (26) and reciprocatingly move between end positions.

Abstract: A pneumatically operated hydraulic pump includes a cylinder housing accommodating a main piston to subdivide the housing interior in two working chambers. The main piston is connected to a hydraulic piston for joint reciprocation so that the hydraulic piston can carry out a suction stroke when the main piston moves to one end position and a pressure stroke when the main piston moves to the other end position. Arranged laterally to the cylinder housing is a control mechanism for regulating a flow of working fluid alternately to the working chambers. The control mechanism includes a plastic valve casing for accommodating a control piston having opposite end faces of different size to define different effective areas and thereby realize reciprocation of the control piston by the working fluid. A slide shoe is guided in the valve casing for conjoint movement with the control piston.

Abstract: A diaphragm pump for pumping a fluid, such as paint, includes a diaphragm separating a first chamber for accommodating and dispensing the paint from a second chamber for accommodating a drive fluid, and a piston that reciprocates to drive the drive fluid within the second chamber in order to flex the diaphragm to provide the pumping action within the first chamber. The diaphragm pump also includes a backing ring mounted adjacent the diaphragm that is configured to distribute the drive fluid across the diaphragm to cause a flexible region of the diaphragm to flex toward the first chamber from the outer perimeter inward toward a central pumping surface in a rolling manner. This diaphragm movement results in substantially all of the paint adjacent the diaphragm within the first chamber to move out of the first chamber when the diaphragm reaches its travel limit, and thus improves the efficiency of the diaphragm pump.

Abstract: A device enables the pumping of any kind of liquid while giving the liquid very high delivery pressure. The units that cause pumped liquid suction and then its delivery are driven exclusively by hydraulic means excluding mechanical means. So that there is no material contact between the driving units and the pumped product and that the product cannot damage the mechanical driving units, the chamber receiving the hydraulic fluid is, at the end of each compression cycle, placed again in direct communication with the hydraulic fluid reservoir.

Abstract: A high pressure hydraulic diaphragm pump having a pressure chamber on one side of a diaphragm and a fluid delivery chamber on the other side of the diaphragm with a reciprocating piston assembly including a piston member being provided for pressurizing the hydraulic fluid in the pressure chamber and having the pressure chamber connected with a pressure regulator which maintains the desired discharge pressure of the fluid and in which the piston assembly is combined with a diaphragm positioning mechanism for maintaining the diaphragm at a desired position relative to the piston member so as to assure full stroke of the diaphragm during normal operation of the pump.

Abstract: A fluid powered diaphragm pump with an adjustable stroke is provided. The stroke of the pump is adjusted by providing an inner diaphragm plate assembly that includes a retractable piston. The piston is biased towards the inner plate by one or more standoffs that attach the piston to the plate. The bias of the piston is overcome by pressurized fluid that is communicated to a chamber defined by the piston and the inner plate. The fluid may be communicated to the chamber through the diaphragm rod. The inner diaphragm plate assemblies of both diaphragm chambers may be connected to different pressurized fluid supplies there enabling the stroke or capacity of the two diaphragm chambers to be controlled independently. As a result, the stroke or capacity of the two diaphragm chambers may differ.

Abstract: A diaphragm pump is provided having a plurality of piston inlets connecting a hydraulic fluid source with the piston chamber and a plurality of check valves each having a ball and valve seat disposed within the inlets. The valve seat includes a conical section sloped such that the tangential contact point between the ball and valve seat is located at a position outward from the inner edge of the valve seat. The distance the ball is permitted to move between the open and closed positions is such that the check valve closes substantially in conjunction with the piston beginning its power stroke and the ball is not able to generate a high closure velocity. A diaphragm plunger includes a spherical surface portion designed to impact a diaphragm stop at a position away from the edges of the stop and plunger. An isolation reservoir is connected to a piston reciprocating chamber such that hydraulic fluid completely fills the piston reciprocating chamber and further flows into the isolation reservoir.

Abstract: A bellows pump exhibiting stable and highly efficient performance. The bellows pump is composed of a first work chamber for admitting fluid, a second work chamber for storing work fluid, a bellows for parting a chamber space into the first and the second work chambers; a plunger being movable in a reciprocative manner to and form the second work chamber; a work fluid chamber which is opened; and a drive member for the plunger.The plunger is provided with a flow channel with a second communication port communicating only at the initial and completing stage of an inflow process of the fluid. A first communication port locates in the vicinity of a top of the first work chamber. The second communication port locates above the first communication port.

Abstract: The present invention relates to a hydraulic pump for use in an ammonia absorption heating and cooling system. The pump is driven by an electric motor that causes a piston to reciprocate within a cylinder. The piston is hydraulically actuated and allows the piston to pump the ammonia through the absorption heating and cooling system below atmospheric pressure. This is achieved through the inclusion of a plurality of ports bored through the cylinder that allow excess lubricant to exit the cylinder during the compression stroke of the piston. The removal of excess lubricant allows the piston to travel through a full stroke, optimizing efficiency, and allowing the ammonia to pumped at pressures below atmospheric.

Abstract: A gas compressor with at least three hydraulic cylinders is connected to a source of natural gas by a gas line. The gas line can also be removably attached to a storage tank. A hydraulic system is also connected to the cylinders. The compressor additionally includes pressure controls which allow the pistons in the hydraulic cylinders to complete the compression stroke in a staged manner. The cylinders are thereby sequentially emptied of gas. Gas at a sufficient initial pressure, entering the cylinders at the completion of the compression cycle, drives the return stroke of the pistons. A pressure switch controls the pressure level of the compressed gas, and aborts the compression cycle when a predetermined pressure in the storage tank has been reached.

Abstract: A diaphragm pump which provides a low internal volume and minimizes volume contributions for applications which require the transfer of fluid volumes on the order of one to several microliters. The pump includes a plunger which reciprocates within a bore and applies fluid pressure to a diaphragm of a head cavity that is connected to the cylinder bore. Hydraulic feed and vent passages connect to the cylinder bore at a point where the end of the plunger passes during reciprocal movement to ensure that the amount of hydraulic fluid within the cylinder bore is consistent during each stroke of the plunger. The pump is particularly useful for supplying receptor media to a Franz cell.

Abstract: The fluid-operated, double diaphragm pump of the invention includes a central housing block having opposed side faces, and a pair of diaphragm housing end sections secured to opposite sides of the central housing block. The diaphragm housings define a pair of enclosures having a common central axis. Mounted in each of the diaphragm housings is a diaphragm that serves to divide each enclosure into an inner pumping chamber, defined by a side face of the housing block and the diaphragm, and a drive chamber defined by the opposite side of the diaphragm and, at least in part, by the inner surface of the respective end section. The central housing block defines inlet and discharge passages for the inner pumping chambers, the flow of material through the passages being controlled by one-way check valves associated therewith. In one embodiment of the invention, the pump also includes a connecting arrangement disposed externally of the pumping chambers.

Abstract: A control system for a piston membrane pump having a pressure chamber is mounted on one side of the membrane, into which chamber a controllable loading and unloading device communicates, computing means connected to the loading and unloading device. Calculations occur in the computer that, dependent on, for example, the actual position of the membrane, the velocity of the membrane, the acceleration thereof, the pressure in the pressure chamber, the beat-frequency of the pump, etc., to determine the length of time for respective delay periods occurring before loading and unloading periods, during which periods hydraulic medium is brought into or allowed out of the pressure chamber by the loading and unloading device.

Abstract: A diaphragm metering pump having control over diaphragm extension is described. A position sensor is incorporated in a diaphragm metering pump to indicate the relative position of the diaphragm during flexure. When excessive extension of the diaphragm is sensed by the position sensor, a control valve will provide hydraulic fluid from a reservoir for inhibiting further deflection of the diaphragm in the direction in which it was moving. Diaphragm life is extended as well as the accuracy of metering provided by the pump maintained.

Abstract: The piston membrane pump has a feed chamber for the fluid to be pumped and a piston working chamber, a membrane hermetically separating the feed chamber and the piston working chamber and a piston oscillating back and forth in the piston working chamber. The piston working chamber is completely filled with a hydraulic medium from a supply container in operation so that the membrane oscillates with the piston. A refill valve which connects the piston working chamber with the supply container cooperates with a spring-loaded sliding control element and a moving force-transmitting element displaceable against it so as to open the valve. So that the pump can operate at higher pressures and temperatures a metal membrane is used, the force-transmitting element is a resilient platelike piece acting against the spring-loaded sliding control element and the membrane has no contact surfaces in the feed chamber on its feed chamber side.

Abstract: A pump has in a housing a revolvable shaft which drives a piston stroke guide body. Drive pistons are provided with piston shoes which run on the guide face of the piston stroke guide body and drive fluid supply pistons of smaller diameter. The pump preferably has a fluid separator between lubricating and non-lubricating fluid, like for example between oil and water, whereof one of the fluids flows through an inner chamber which is provided with inlet and outlet valves while the other fluid acts in an outer chamber which is open toward the cylinder wherein the fluid supply piston reciprocates. Dead space fillers are provided to prevent losses by compression of fluid and seal means are assembled to prevent leakage of fluid from one into the other of the chambers. The fluid separator may be compressible and expandable within the elasticaly deformable range of the material whereof it is made.

Abstract: An apparatus for controlling the hydraulic circuit of a piston diaphragm pump, having at least a pump diaphragm alternatingly subjected to the presure or the suction stroke of a piston operatingly connected to driving means, the apparatus comprising control means changing the amount of hydraulic medium displaced by the piston in dependence of a power demand or the like. A displacement sensor is associated with one side of the diaphragm facing the hydraulic medium, the sensor measuring the stroke travel of the diaphragm and generating a corresponding stroke travel signal which is transmitted to control means, the control means including storage means storing predetermined stroke values and/or stroke value ranges for predetermined hydraulic power values of the pump.

Abstract: A pulse combustion powered apparatus is disclosed for temperature conditioning and pressurizing fluids. The alternating periods of positive and negative pressure of the combustion gases of a pulse combustion burner drive a reciprocating compressor and the rejected engine heat is recovered by heat exchange with a primary fluid. The compressor may be included in a reversible refrigeration circuit to provide heating and cooling of secondary fluids.

Abstract: A pulse combustion powered apparatus is disclosed for temperature conditioning and pressurizing fluids. The alternating periods of positive and negative pressure of the combustion gases of a pulse combustion burner drive a reciprocating compressor and the rejected engine heat is recovered by heat exchange with a primary fluid. The compressor may be included in a reversible refrigeration circuit to provide heating and cooling of secondary fluids.

Abstract: In a piston diaphragm pump, comprising housing portions clamped together by clamping bolts, a diaphragm, sealingly clamped between adjacent housing portions for separating a feeding chamber from a working chamber, and a reciprocating piston acting in said working chamber filled with hydraulic medium for deflecting the diaphragm to change the volume of the feeding chamber, there is provided at least one supporting member to be screwed to a respective supporting thread in one of said housing portions so as to project towards another housing portion by a distance depending on its screwed position and to abut in the assembled position against an abutment surface on said other housing portion.

Abstract: A fuel injection system is provided for a multicylinder internal combustion engine. Each cylinder is provided with at least one fuel injector. The system includes a cam-operated pumping plunger which maintains fluid pressure within an accumulator and controls the intermittent application of fluid pressure from the accumulator through a first chamber in which the plunger moves to one end of a metering plunger. The opposite end of the metering plunger coacts with a second chamber in which the metering plunger moves to define a cavity into which fuel is supplied for subsequent feeding to the cylinder injector. Fuel enters the cavity during those periods when the metering plunger is not subjected to the accumulator fluid pressure, the latter being under the control of the pumping plunger. The pumping plunger reciprocates within its chamber and is rotatable about its longitudinal axis. An elongated groove is formed in and encompasses the exterior of the pumping plunger.

Abstract: Fuel injection pump of the type arranged to inject fuel into engine cylinders with the fuel flow being controlled by an electromagnetic valve, comprises a rotor arranged to rotate in timed relation to engine rotation, and a shuttle movably received in an axial bore made in the rotor. Opposite sides of the shuttle define first and second chambers within the axial bore, where the first chamber is used as a compression chamber to pressurize fuel introduced therein via the electromagnetic valve to inject the same into engine cylinders, and the second chamber is communicable with a low pressure fuel reservoir. Fuel is fed into the first and second chambers during an intake stroke or mode, and then the second chamber fuel is pressurized by means of an inner cam mechanism so that the shuttle moves toward the first chamber to pressurize the fuel therein, thereby injecting the fuel during a compression stroke.

Abstract: A piston diaphragm pump includes a support plate, disposed on the side of the piston work chamber, for the diaphragm, which is held in a freely movable manner counter to the pressure of a plurality of springs engaging its circumference. A control push rod under the pressure of another spring, counter to the support plate, engage the circumferential area of the support plate and has a conical recess on its circumference, along which slides a displaceable locking member for a refill valve for the hydraulic fluid during the movement of the control push rod. The refill valve opens only when the support plate displaces the control push rod counter to the pressure of its spring as a consequence of a lack of hydraulic fluid in the pump.

Abstract: A distribution type fuel injection pump for distributing and pumping a fuel into a plurality of cylinders of an internal combustion engine. The fuel injection pump is constructed of a hydraulic head formed with first and second fuel feed ports, a rotor fitted in the hydraulic head, and plungers fitted in the end portion of the rotor for effecting the pumping action in accordance with the rotations of the rotor. Separately of this rotor, there is formed in the hydraulic head, for example, a pressure space in which a shuttle is slidably fitted to partition the pressure chamber into first and second pressure chambers. The fuel, introduced from the first fuel feed port and compressed by the plungers, is guided into the first pressure chamber of said pressure space in accordance with the rotation of the rotor, and the fuel, is introduced into the second pressure chamber, is consecutively distributed and pumped into the respective engine chambers by the movements of the shuttle.

Abstract: A surface power unit for use on a subterranean well generates a series of pulses of pressurized fluid to a downhole pump. A pump means generates a flow of fluid from a reservoir through a charging line to a charging side of a cylinder. A piston is slidably disposed within the cylinder, dividing the cylinder into the charging side and a power side. Position or pressure transducer means responsive to the movement of the piston generates control signals representing the position of the piston in the cylinder. The charging line can include a first valve means responsive to one of the control signals for regulating the flow of fluid through the charging line. A return line is provided for returning fluid from the charging side of the cylinder to the pump means. The return line includes a second valve means responsive to another one of the control signals for regulating the flow of fluid through the return line.

Abstract: The present invention relates to a hydraulically controlled diaphragm pump, comprising an intermediate chamber filled with fluid, and a re-filling conduit for said chamber.According to the invention, means are provided for controlling the closing and the opening of the said conduit, which means are constituted by a valve cooperating with a fixed seat through which the said re-filling conduit reaches into the said intermediate chamber. Said valve is mounted for sliding on a rod, which rod is also mounted for sliding longitudinally inside a fixed support in the said intermediate chamber and traverses the said seat, a shoulder of the said rod forming means for moving the said valve and holding it on its seat, an actuating surface of the said rod, opposite the said shoulder, forming the rear of the diaphragm and a spring being coupled between the said support and the said actuating surface for closing the said valve.The invention finds an application in the field of mechanical engineering.

Abstract: A diaphragm pump operated by vacuum pressure and having a switching arrangement to control the continuous alternations between the intake stroke caused by vacuum pressure and the working stroke caused during venting by a spring after the end of each stroke. The switching arrangement consists of a crack-open valve between vacuum pressure chamber and a space continually connected to atmosphere, and a plunger, fastened to the diaphragm; the length of the plunger is variable through a spring clutch. The special action of the switching arrangement is based on the fact that the plunger requires a larger force for cracking the valve than afterwards for keeping it open. This is accomplished by having a differential pressure, act in the closing direction on the valve, and eliminating this force after opening, causing the spring-loaded plunger to extend to its full length and to keep open the valve during the entire working stroke of the diaphragm.

Abstract: Apparatus for an improved diaphragm pump wherein hydraulic shock and mechanical wear to the diaphragm membrane is reduced by providing a circular reed valve member adjacent to the diaphragm. The reed valve member provides a barrier to pressurized hydraulic fluid jets from direct impingement upon the diaphragm membrane, and provides a valve closure member for reducing hydraulic shock effects on the diaphragm membrane.

Abstract: A piston pump with a controllable stroke is described. It is a positive displacement type pump with several stages and also a continuous variable stroke. The pump piston is only effectively connected with the drive during the working stroke. For example, the pump serves particularly for controlling the braking force in an anti-locking system for vehicles. In every pump cycle it can vary the volume in the braking system, and thus the brake force, without letting fluid out of the brake system. It makes possible the amplitude control of brake pressure pulsations and a desirable brake pressure course. In addition, an anti-locking system with a special two-stage pump device is described. Furthermore, a hydraulic circuit of great utility for anti-locking systems is shown.

Abstract: Apparatus is disclosed for unloading excess pressures developed in a hydraulic diaphragm pump, wherein the pressure of the pumped fluid is sensed by a control diaphragm connected to an unloading valve which is placed in a passage connecting the hydraulic displacement chamber with a hydraulic oil reservoir.