Abstract: An apparatus for continuously pumping fluid at a substantially constant flow rate is disclosed. This apparatus is comprised of a metering pump, a rotary timing valve, at least three fluid transducers, and means for synchronizing said metering pump with said rotary timing valve.

Abstract: A diaphragm pump with a flat diaphragm which is held between the face surface of a pump head and the corresponding face surface of a hydraulic block is improved in that the annular clamping region has an angling step such that the clamped-in diaphragm is bent in its outer annular border region. In this way, a sealed tightness is achieved over long time periods, as well as inducing a uniform diaphragm tension which effects performance of the pump advantageously. Inventive valve designs are provided which allow removal for cleaning from outside the assembled pump and also allows manual opening of the valves for unclogging. An efficient design is provided for a pump head.

Abstract: A hydraulically activated double-acting piston pump comprising a pump body with an inlet and outlet for the production fluid, and an inlet and outlet for the hydraulic fluid. Thereby eliminating the need for sucker rod strings in pumped wells. A partition located between two coaxial hollow cylinders for keeping the production fluid separate from the hydraulic fluid.

Abstract: A compressor with a flexible diaphragm used as the pumping element such as for Stirling coolers or pulse-tube refrigerators, said compressor further including a sensor to monitor the position of the diaphragm and a control circuit for maintaining the diaphragm position in a preselected range to avoid contact between the diaphragm and the rest of the compressor. The compressor also includes an expansion member for compensating for the thermal expansion of the working fluid of the compressor.

Abstract: In a diaphragm or membrane pump, the diaphragm thereof is composed of two diaphragm disks arranged at an axial distance from one another and enclosing an interior space whose size is variable given damage to one of the diaphragm disks. Further, a signal generator is arranged in that diaphragm disk facing toward the conveying chamber and a signal pick-up is arranged in the pump housing, this signal pick-up being connected to a means for the electronic evaluation and amplification of the signals output by the signal pick-up. This embodiment makes it possible to recognize a potential damage to the diaphragm early and to thus reliably prevent hydraulic medium from proceeding into the conveyed medium.

Abstract: A heat pump system (10, 210) includes a power section (11, 211) having a generator (15, 215) for converting a first working fluid from a liquid to a relatively high pressure gas, a power unit (25, 222) providing energy by the conversion of the relatively high pressure gas to relatively low pressure gas to power a drive piston (27, 228') for intermittently delivering a power stroke, a power section condenser (51, 251) converting the first working fluid from relatively low pressure gas to the liquid, a compressor section (12, 212) intermittently driven by the drive piston, the compressor section having a compressor (75, 275) converting relatively low pressure gas second working fluid to relatively high pressure gas second working fluid for circulating the second working fluid through a compressor section condensor (108, 308) and a compressor section evaporator (115, 315) to effect heating and cooling operations.

Abstract: A high-pressure hermetic compressor suitable for use in a zero-gravity environment. The compressor includes a solenoid, driven by a power supply, which causes a plunger to reciprocate in an internal space filled with hydraulic fluid. Such motion pressurizes the hydraulic fluid causing a diaphragm to distort. The deformation of the diaphragm compresses fluid in a compression chamber.

Abstract: A compressor with a flexible diaphragm used as the pumping element, said compressor further including a sensor to monitor the position of the diaphragm and a control circuit for maintaining the diaphragm position in a preselected range to avoid contact between the diaphragm and the rest of the compressor. The compressor also includes an expansion member for compensating for the thermal expansion and compressibility of the working fluid of the compressor.

Abstract: A diaphragm pump with a pumping component composed of a paint stage and propulsion stage; a hydraulic component; and an engine component such as a motor, fashioned such that, in a first predefined position or orientation the hydraulic component and the motor are mounted to each other in side-by-side arrangement, and the pumping component sits on top of the hydraulic component, whereby it is possible to cant the diaphragm pump by 90.degree. and thus bring it into a second operable position for orientation. Unguided paint valves are thereby applied such that, in both positions of the pump, they enclose the same angle with the horizontal line. A measuring stick and an intake line are strategically arranged to be useable in both positions of the pump. A stationary support frame and a mobile support frame are presented to facilitate the flexible positioning or orientation of the pump.

Abstract: A low volume, hydraulic powered pump for attachment to small diameter, coiled tubing for pumping subsurface liquids from hydrocarbon formations. The pump is easily run into existing production well tubing by use of a coiled tubing unit and then connected to a power fluid pressuring apparatus. Power fluid actuates an actuator in the pump to pump liquids in the formation to the surface. The actuator has two piston heads connected by a connector rod which reciprocate in two separate chambers in the pump which are divided by a cross head seal member. A conduit in the actuator allows power fluid to be forced into the lower chamber to drive the actuator downward pumping subsurface liquids to the surface. Once the actuator completes its down stroke, pressure on the power fluid is released and the actuator is driven to its retract position by the hydrostatic pressure of the subsurface liquids pressing against the bottom surface of the upper piston head.

Abstract: Pumping apparatus which compresses or decompresses an actuating fluid alternately, which is in turn used to pump an artificial heart. To reduce the size of the apparatus, a diaphragm which contains a non-compressible actuating liquid is driven reciprocatingly by an electric linear motor. To prevent the occurrence of an excessive suction pressure which may be caused by the non-compressibility of the actuating fluid, at the commencement of the suction interval, the current to energize the linear motor is increased gradually and the pressure of the actuating liquid is detected. When the liquid pressure goes out of a selected safety range, the gradual increase ceases. A discharge stroke is detected from an integrated value of the motor current during the discharge interval, and when it reaches a given value, a reversal of the direction of energization of the motor is initiated.

Abstract: 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 gas within the pulsator chamber may be purged or bled into an annular space and there out into a reservoir and scrubbing chamber. Additional hydraulic fluid will flow into the pulsator chamber. Upon the down stroke of the plunger an exact amount of volume will be displaced within the pulsator chamber. Adjustment of the product pumped on each stroke is by sacrificing a measured amount of the pulsator liquid into a sacrifice chamber. The amount of liquid which flows into the sacrifice chamber upon each down stroke and out of the chamber on each upstroke is adjusted by adjusting the movement of a floating piston by a micrometer rod.

Abstract: An injection molding apparatus where the position of the auger can be accurately determined from the position of the electric linear motor. The electric linear motor is in direct communication with a first hydraulic piston and cylinder. The first hydraulic piston and cylinder is in hydraulic communication with a second hydraulic piston and cylinder. The second hydraulic piston and cylinder is in direct communication with the auger. Thereby, the position of the auger can be accurately controlled by controlling the position of the electric linear motor.

Abstract: When pumping chambers were provided between tapered discs of axial compressibility and expandability, the discs worked perfect in the subcritical pressure range. But in the supercritical pressure range the high pressure in fluid would depart the discs away from each other and open a gap between the discs because the force of pressure in fluid in the chamber between the tapered discs was higher than the internal strength of the material of which the respective coned element was made. The invention now discovers that it is possible to provide a means which prevents the departure of a coned ring from a neighbored ring. The invention obtains this by providing a means which presses under actions of pressure in surrounding fluid the neighboring coned ring elements at all times together for a close and perfect sealing between them.

Abstract: A precision liquid dispenser embodying the present invention includes a displacement diaphragm pump and a hydraulic system for selectively deforming the diaphragm. The diaphragm pump includes a pump body, a pump cavity, a pump diaphragm, and an input/output port. A solenoid operated valve assembly selectively connects the port to a source of liquid to be dispensed. The hydraulic system for selectively deforming the diaphragm includes a body with a cavity, a piston, a sealing ring, and hydraulic fluid in the space between the piston and diaphragm. The position of the piston is controlled by a stepping motor, a mechanical threaded coupling, which converts rotary motion of the motor output shaft to linear motion of the piston. The volume of fluid dispensed is determined by the number of pulses applied to the stepping motor. The output flow rate as a function of time is controlled by the rate of pulses applied to motor as determined by the control logic.

Abstract: A pump consists of a valve box in which a valve chamber inlet and outlet are each provided with a valve, and a reciprocating member in a cylinder that communicates with the valve chamber of the valve box to open the valves. A pressure action chamber is provided between the valve box and the cylinder and a pressure force member divides the pressure action chamber into a valve chamber side and a cylinder side. On the cylinder side of the pressure action chamber thus divided is an action medium that transmits to the pressure force member changes in the volume of the pressure action chamber produced by the action of the reciprocating member. A valve device consists of a concave valve seat and a number of fluid passages formed therein. Which open into the recess formed by the concave valve seat. Either the valve seat or the valve-piece is formed of, or covered with, a hard resilient material, or one is formed of the hard resilient material and the other is covered with a hard resilient material.

Abstract: A rotary piston pump assembly includes a rotary piston pump having a pump housing. First and second outlets lead fluid out of the pump housing. The fluid is returned into the pump housing through the first outlets and the first outlets are closed during a portion of the rotation of the pump.

Abstract: A method and apparatus for pumping water, oil, or other production fluid up a production tube from a well or the like to achieve greater efficiency as compared to conventional pumpjacks. A hydraulic actuator unit with its own hydraulic fluid incorporates pressure sensing valves to move a hydraulic piston through a power stroke and a resetting stroke. A power transmission tube having its own power fluid transfers pressure from the hydraulic actuator to a downhole piston assembly to pump the production fluid directly up the production tube during a power stroke. The static head of the production fluid in the production tube resets the downhole piston assembly during the resetting stroke. The pressure sensing valves enable the hydraulic piston to extend its power stroke a sufficient distance to pressurize the power transmission fluid and move the downhole piston assembly through its entire production stroke independent of the compressibility of the power transmission fluid.

Abstract: In a diaphgram pump with a diaphragm that separates a delivery chamber from a work-chamber filled entirely with fluid medium, and with a piston chamber which is connected to the diaphragm work-chamber by way of at least two passages and in which a displacement piston is reciprocatingly movable to effect the oscillatory actuation of the diaphragm, with the passages for flushing out gas bubbles shaped in such a manner that the mean velocity of flow in each single passage is always aimed in one stroke direction. The arrangement and shape of the passages connecting the work-chamber with the piston chamber is provided here in such a manner that the total resistance to flow of all the passages, made up of the parallel resistances of the individual passages, is different in one direction of flow than that in the other direction of flow, and that thereby there results in all passages a total transport flow for any gas bubbles contained in the fluid medium.

Abstract: Apparatus for monitoring the diaphragm integrity in a diaphragm pump. A single continuous circuit trace is supported on a pump diaphragm. An electrical circuit is connected to the continuous circuit trace for measuring both the continuity and a potential ground fault condition between the circuit trace and pumping liquid. The circuit trace is formed in a configuration which resists the effects of strain induced by continuous flexing of the diaphragm.

Abstract: An electropneumatic converter is provided comprising a gear pump. The two othed wheels are driven by two electric motors rotating at high speed in opposite directions. The control circuits for each of the motors are independent and a single motor may drive the pump permanently.The converter is used, for example in an activator for a cardiac module or artificial heart.

Abstract: Pump actuator assembly for use in operating a pump for supplying intravenous liquid to a patient which comprises a housing having a sealed chamber therein with a portion thereof being covered by a flexible membrane. A plunger is mounted in the housing so that a portion thereof is disposed in the sealed chamber for movement between innermost and outermost positions. A constant quantity of liquid fills the sealed chamber. A booth encloses the portion of the plunger disposed in the fluid. A liquid-tight seal is provided between the booth and the housing to permit the plunger to be moved between the innermost and outermost positions so that the flexible membrane can be caused to move between extended and retracted positions.

Abstract: A positive displacement reciprocating pump for conveying a liquid or gaseous fluid is disclosed and which comprises a fluid enclosure having a movable piston means mounted therein which sealably divides the enclosure into a pumping chamber on one side and an actuating chamber on the other side. The piston means may comprise either a slideable piston or a flexible diaphragm. An inlet valve and a separate outlet valve are each connected to the pumping chamber, and a control system is provided for intermittently supplying a pressurized working fluid to the actuating chamber so as to intermittently move the piston means in the discharge direction, with the piston means being moved in the opposite or suction direction by either the pressure of the fluid being conveyed, or a suitable spring.

Abstract: In a pumping apparatus having a flexible diaphragm a disc is arranged for supporting the diaphragm. The support disc has holes through which the pump liquid passes. For preventing the diaphragm from being drawn into the holes plugs are inserted in the holes in such a way that openings or slots are formed which are sufficiently wide for the liquid to flow therethrough but are not wide enough for the diaphragm to be sucked into the support disc. The diaphragm is thus prevented from becoming damaged. Various embodiments of suitable plugs are illustrated which either form the narrow openings in combination with the surrounding wall of the holes in the support disc or are provided with holes or slots in the plug body.

Abstract: A submersible pumping unit having a diaphragm pumping chamber connected to one end of an elongated tube, the interior of the tube being filled with hydraulic oil and a reciprocable solid of like density, the other end of the tube being connected to an oil chamber including a reciprocable piston for developing hydraulic pressure and flow oscillations at a predetermined frequency, wherein the hydraulic pressure and flow oscillations are transferred via the tube and the solid in the tube to the diaphragm pumping chamber for pumping the liquid in which the diaphragm pumping chamber is submersed.

Abstract: A redundant, pneumatic driver for a blood pump in which a pair of pistons are contained in a common cylinder and their stroke rates and lengths are selectively controlled by a controller which non-invasively senses the circulatory system requirements of the patient in which the blood pump is implanted. The controller varies the stroke rates and lengths to meet such requirements and further is able to selectively switch driving functions from one piston to the other to provide a redundant driving capability.

Abstract: An injector pump for introducing metered amounts of fluid into a process line which pump typically is actuated by a gas powered timing relay. A diaphragm or other impermeable member mounted in the pump housing defining a pump chamber for the fluid to be pumped and a piston chamber for a piston having a plunger sliding in a plunger guide to define a pressure chamber between the plunger and the diaphragm. A high pressure seal is carried in the plunger guide to provide sealing about the plunger when there is a high pressure in the pressure chamber, while permitting leakage along the plunger when there is a low pressure in the pressure chamber, thereby providing for pumping of measured amounts of fluid which may be under high pressure and/or highly corrosive, while maintaining isolation between the pump mechanism and the fluid.

Abstract: A novel system is described for withdrawing liquids from a subsurface horizon utilizing a tubular diaphragm pump. A specific and unique pump is disclosed comprised of an elongated body member which includes a main chamber member extending longitudinally of the body member. In a preferred embodiment, a delivery tube is concentrically mounted within the chamber and forms an annulus with its outer surface and the inner walls of the chamber. The tube is provided with spaced perforations along its length within the chamber. Upper and lower check valves are in fluid communication with and at opposite ends of the delivery tube. Flexible tubing or a bladder is placed in the annulus and is normally spaced from the delivery tube.

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 two-stage pump for LPG having two chambers, a valve communicating with the first chamber for the admission of the liquid to be pumped; a second valve communicating with the second chamber for the delivery of the pumped liquid. A transfer duct connects the two chambers and is fitted with a check valve to prevent the return of liquid from the second chamber to the first. Each chamber comprises a wall formed by a diaphragm freely deformable in such direction as to increase the volume of the chamber under the effect of the pressure of the liquid, and operably deformable in the opposite direction under the action of actuating means acting alternately on the diaphragms of both chambers. The floating diaphragms prevent the vaporization of the liquid that would arise with a suction pump, as well as the cavitation that would ensue.

Abstract: The automatic purger has an intermediate chamber (11) one of the walls of which is formed by an elastic diaphragm (10), termed front diaphragm, whereas the other wall is formed by a second elastic diaphragm (12), termed rear diaphragm. This chamber is connected to a purger (20) formed by a body (21) defining a small internal enclosure (22) in which an element (25), which is highly permeable to the gas, is disposed. The invention is applicable to a hydraulically controlled or actuated pump of the reciprocating or displacement type.

Abstract: A well pumping system in which a production piston having a traveling valve therein is arranged in a production cylinder with a standing valve in its inlet and is reciprocated by a power piston attached to the production piston in which power for reciprocating the production system is provided by hydraulic fluid acting on the rod end of the power piston to move the piston in one direction and when the force on the power piston fluid is removed, the hydrostatic head of pressure acting on the head end of the power piston moves the pair of pistons in the opposite direction either by the power fluid having lesser weight than the production fluid or by isolating the hydrostatic head of fluid in the tubing from the production cylinder so that the production cylinder is subjected to bottom hole pressure which will be less than tubing pressure at the pump resulting in return movement of the pistons.

Abstract: A diaphragm pump is disclosed which includes flow channels (12;12a) within pressure chambers (9;9a), at least one of the walls defining the flow channels being in the form of a diaphragm wall (16,17; 16a,17a). A driven piston (A;B) displaces a liquid within the pressure chambers (9;9a) to cause cyclical changes in the volume of and pressure subsisting within the flow channels. Compensating pistons (S;T) are disposed generally opposite each of the driven pistons (A;B) and the compensating pistons are connected to a common hydraulic circuit such that the compensating pistons remain in position until the pressure in one of the pressure chambers (9;9a) exceeds a predetermined pressure, whereupon the compensating pistons (S;T) react in a manner tending to prevent further rise in the pressure in that chamber.

Abstract: A well pump having a power fluid that is to be reciprocated in a conduit so as to power a downhole pump by filling the downhole pump and the lower portion of the power conduit with a hydraulic oil having a specific gravity greater than water and filling the rest of the power conduit with a less compressible fluid such as water.

Abstract: A piston and a cylinder within a pump housing cooperate with the inner walls of the housing to form a high-pressure reservoir surrounding the cylinder to provide a continuous compressive force thereon to prevent tensile stresses in the cylinder during pumping operations to prevent failure of the cylinder due to metal fatigue. A check valve between the cylinder and the reservoir permits high-pressure fluid to flow from the cylinder into the reservoir during pumping operations to maintain substantially the maximum cylinder pressure within the reservoir. The cylinder further includes therein an inlet with an associated check valve. Stationary seals in the pump use the high pressures in the cylinder and the reservoir for producing the sealing forces necessary to prevent leakage. The primary piston seal consists of a long, controlled clearance gap which permits a small leakage but has only minor contact and thereby low sliding stresses and a long life.

Abstract: A fluid pressure ratio transformer which may be utilized to couple pressure variations in a working fluid operating at a given input pressure ratio to a fluid coupled load operating at a different required output pressure ratio. The device is self-modulating to pump-load, whether operating at fixed stroke or fixed frequency. The pressure ratio transformer comprises a housing and a positive displacement element within the housing dividing the housing interior into first and second chambers, each of which is filled with a compressible fluid. The working fluid in the first chamber is subjected to periodic pressure oscillations while the fluid in the second chamber is either coupled to a fluid load or may itself be the pumped fluid. The effective spring coefficients and the mass of the piston are matched to the frequency of operation so that the piston oscillates at its natural frequency.

Abstract: A four piston hydraulic pump driven by a four cylinder free-piston Stirling engine has four stepped pistons operating out of phase in pairs. The hydraulic fluid pumped between the hydraulic cylinder can be tapped for hydraulic power. The stepped pistons give the option of utilizing low flow/high pressure, or high flow/low pressure. The non-utilized flow ensures that the timing between pistons will always remain correct. Since the arrangement is symmetrical, it remains balanced.

Abstract: A new mechanism for pulsation damping in a reciprocating diaphragm pump system is disclosed which is especially suitable for solvent delivery in modern high pressure liquid chromatography requiring a wide range of solvent flow rates and pressures. The disclosed damper has good overall performance over the full range of liquid chromatographic conditions, a dead volume independent of solvent pressure, and largely eliminates the necessity for continuously pumping the working oil of the diaphragm pump to a maximum operating pressure.

Abstract: A compressor, pump, or alternator apparatus is designed for use with a resonant free piston Stirling engine so as to isolate apparatus fluid from the periodically pressurized working fluid of the Stirling engine. The apparatus housing has a first side closed by a power coupling flexible diaphragm (the engine working member) and a second side closed by a flexible diaphragm gas spring. A reciprocally movable piston is disposed in a transverse cylinder in the housing and moves substantially at right angles relative to the flexible diaphragms. An incompressible fluid fills the housing which is divided into two separate chambers by suitable ports. One chamber provides fluid coupling between the power diaphragm of the RFPSE and the piston and the second chamber provides fluid coupling between the gas spring diaphragm and the opposite side of the piston. The working members of a gas compressor, pump, or alternator are driven by the piston.

Abstract: A method and apparatus for pumping fluids, especially viscous and/or abrasive fluids, are disclosed. The method comprises using one working fluid to pump an intermediate working fluid, which may be different from the first working fluid, through a conduit system in a smooth and continuous pulsating manner. The intermediate fluid pumps the process fluid through the actual pumping zone. Heat exchange between the intermediate and process fluids may be effected, e.g. by counterflow. The preferred apparatus comprises a hydraulically operated displacement pump. A tubular diaphragm pump is coupled in-line in a pipe line. The tubular diaphragm pump includes a housing coupled to the pipe line, and a tubular diaphragm coupled to the housing in such a manner that the process fluid flows from the pipe line, through the interior of the tubular diaphragm and back into the pipe line. A check valve insures that the process fluid passes through the tubular diaphragm in a single direction.

Abstract: A hydraulic drive system operating from the periodic pressure wave produced by a Stirling engine along a first axis thereof and effecting transfer of power from the Stirling engine to a load apparatus therefor and wherein the movable, or working member of the load apparatus is reciprocatingly driven along an axis substantially at right angles to the first axis to achieve an arrangement of a Stirling engine and load apparatus assembly which is much shorter and the components of the load apparatus more readily accessible.

Abstract: In a diaphragm pump the diaphragm separating the delivery chamber from the working chamber is clamped between a cylinder body and a cylinder cover in pressure-balancing arrangement. For this purpose a pressure-balancing space is provided to be radially outside and to encircle said diaphragm clamping surface, the pressure balancing space communicating with the working chamber through at least one communicating passage. Furthermore, a separate annular seal member is disposed to be radially outside the pressure balancing space chamber between the cylinder cover and the cylinder body to seal-off the pressure balancing space and the working chamber from the outside. This enables the diaphragm pump to be used at discharge pressures far greater than 350 bars and simultaneously permits the use of plastic diaphragms which are reliable in operation and have a large displacement capacity.

Abstract: The apparatus comprises at least one positive displacement pump, which is driven by the sea waves. The quantity of delivery of this pump is adjustable in accordance with the lengths of strokes made by the ocean waves. This is made possible in that the positive displacement pump comprises pistons having different volume displacements. The height of the incoming waves is measured by a membrane box connected to a transducer which generates signals such that only that piston of the plurality of pistons is made to operate, which has by design a volume displacement which gives the optimal recovery of the energy of the ocean waves. The or these pistons pump a working fluid into a storage vessel, which allows the generation of peak load as well as base load electrical energy.

Abstract: A combined surface power unit and velocity actuated valve for a downhole pump is disclosed. The surface power unit generates a series of pulses of pressurized fluid. A power line supplies the fluid pulses to a downhole pump. Within the downhole pump, a piston means is slidably disposed for pumping fluid therefrom. The piston means includes an orifice for permitting fluid flow therethrough. The velocity of the fluid passing through the orifice causes a pressure differential across the orifice and valve means closes for the duration of each pulse. When the valve means is closed, pressure builds up in the downhole pump causing the piston means to move in a power stroke, pumping the production fluid. Between pulses, the pressure of the fluid in the downhole pump drops and a velocity valve opens. When the velocity valve is opened, fluid can flow freely therethrough, and the piston means retracts under the influence of gravity in a re-charging stroke.

Abstract: A downhole pump for use in a well which includes a casing, a coaxially aligned tubing within the casing for transporting fluid, and fluid filling the space between the tubing and casing. A bottom seals the casing and tubing and includes an upward-flow check valve which permits fluid flow only from beneath the bottom into the tubing. A bucket having an open top, a closed bottom and an annular fin extending from the side thereof is constrained within the tubing. The bucket bottom also includes an upward-flow check valve. A plunger mounted on the tubing over the bucket cooperates with the bucket to form a cavity, the size of which increases as the bucket moves downward within the tubing. A third upward-flow check valve is mounted on the plunger to permit fluid flow from within the bucket to the tubing over the plunger. Holes are formed in the casing between the bottom and the annular fin of the bucket to permit fluid communication between the casing and lower portion of the tubing.

Abstract: A low trauma, reversible flow pumping system is disclosed which is useful for transfer of biological fluids containing fragile components such as cells. The pumping system comprises a length of collapsible and flexible tubing in fluid communication at each end with a two-way, gravity actuated check valve means having a self-centering, vertically slidable weight member for directional regulation of fluid flow. Said tubing is sealingly enclosed within a hydraulic fluid containing chamber which is in fluid communication with oscillatory pressure providing means to cause alternate expansion and contraction of said tubing.

Abstract: In accordance with the present invention, a pumping unit (10) is disclosed. The pumping unit includes shell structures (20, 22) each having a diaphragm (32, 38) therein to divide the pumping chamber within the structure into first and second compartments. One-way valves permit material to travel from an inlet source to the first compartment and from the first compartment to an outlet source. Deflection of diaphrams provides the impetus to draw material to the first compartment from the inlet source and drive the material to the outlet source. The motion of the diaphrams is induced by a reciprocating piston assembly (94) within a cylinder (84). The motion acts through intermediate chambers (110, 112) filled with pumping fluid and acting on the opposite side of the diaphrams from the first compartments. This permits isolation of the piston from the material being moved to prevent contamination.

Abstract: A cardiac prosthesis having a hydraulically actuated compressible blood pump. An actuation chamber adjacent the blood pump receives hydraulic actuation fluid from an actuator pump through a three-way ventricular dump valve to compress the blood pump during systole and eject blood therefrom. During diastole the actuation fluid is permitted to drain from the actuation chamber through the three-way valve into a reservoir. The valve includes inlet and outlet manifolds and synchronously movable valve members within each manifold for controlling the flow of actuation fluid into and out of the actuation chamber.

Abstract: A total cardiac prosthesis having a pair of hydraulically actuated compressible blood pumps. An actuation chamber adjacent each blood pump receives hydraulic actuation fluid from a separate actuator pump to compress the blood pump during systole and eject blood therefrom. During diastole the actuation fluid is permitted to drain from the actuation chamber into a reservoir. One of the actuator pumps delivers actuation fluid to its associated actuation chamber through a three-way ventricular dump valve, which directs fluid directly to the reservoir during diastole. The other actuator pump is a reversible pump which repeatedly reverses its pumping direction to effect systole and diastole in its associated blood pump.

Abstract: An improved hydraulic pump wherein a piston is mechanically reciprocated by a suitable drive in an oil chamber, and a second piston is caused to reciprocate by the oil pressure developed in the chamber, the second piston also reciprocating in a pumping chamber to cause the pumping of a liquid through the pumping chamber; a diaphragm attached to the second piston provides liquid isolation between the oil chamber and the pumping chamber.