Abstract: A gap seal device includes a housing with a fluid-filled guiding chamber and a multi-part piston that is translationally and/or rotationally moveable in the guiding chamber. The piston separates a high-pressure region from a low-pressure region of the guiding chamber. The piston forms an annular gap having a nominal gap width with an inner wall delimiting the guiding chamber. The piston has a stepped rod, a sleeve, which is slipped over a stepped-down region of the rod and which has a blind hole, and a coupling. The stepped-down region of the rod or in a tube portion of the sleeve includes a stiffness change. A gap width of the annular gap that is reduced compared with the nominal gap width can be set in a region radial to the stiffness change by stress-caused expansion of an outside diameter of the tube portion of the sleeve in accordance with the set stressing force.

Abstract: An air pump with an external pressure release valve includes an air pump body, a flow channel seat and at least one air valve. The air pump body comprises a driving motor and at least one air bag group for generating air flow. The flow channel seat includes an airflow channel and a pressure release channel communicated with the airflow channel and extending to any side wall surface of the flow channel seat. The side wall surface includes an installation hole of an outlet of the pressure release channel. The installation hole includes a pressure release assembly arranged inside the pressure release channel. Because the air pump includes the pressure release channel, and the pressure release channel extends to any side wall surface, the air pump is respectively connected with different objects to be inflated, meanwhile, an assembler can more easily adjust the output air pressure of each air pump.

Abstract: A mechanical pump includes a motor with an output shaft, a cam coupled to the output shaft for rotating the cam when the motor is energized, and a driver with spaced ledges engaging the cam and driven linearly by the rotating cam. The piston is driven by the driver. A cylinder receives the piston therein and includes an inlet section for drawing fluid into the cylinder and an outlet section for pumping fluid out of the cylinder as the piston reciprocates in the cylinder.

Abstract: The invention provides an apparatus comprising a storage tank, a liquid piston compressor and a gas-fed device. The storage tank is configured to store liquefied gas therein. The liquid piston compressor is disposed downstream of, and in fluid communication with, the storage tank and is configured to receive boil-off gas from the storage tank and to compress the gas. The gas-fed device is disposed downstream of, and in fluid communication with, the liquid piston compressor, and is configured to receive compressed gas from the liquid piston compressor.

Abstract: A fluid-driven chemical product dispensing system dispenses fluid chemical product concentrates. The dispensing system includes a fluid drive unit powered by flow of a fluid, such as a diluent, and a pump which delivers the fluid chemical product concentrate from a supply to a destination. Upon exit from the fluid drive unit, the diluent is also delivered to the destination, where it mixes with the dispensed fluid chemical product concentrate to form a use solution. The dilution ratio of the volume of fluid chemical product concentrate dispensed per unit time versus the volume of diluent exiting the drive unit per unit time is constant over a defined range of diluent flow rates.

Abstract: A method is provided for actively compensating for pressure changes of a working fluid within a conduit. A first cavity is provided in fluid communication with the conduit. A second cavity is in fluid communication with a control fluid. A plunger is in communication with both the first cavity and the second cavity and is movable in response to pressure changes of the working fluid in the conduit. The plunger is re-centered. Re-centering the plunger includes the following steps. Position data representative of movement of the plunger is collected. The position data is analyzed with a control unit to determine an average position of the plunger which is offset relative to a center position. The average position of the plunger is compared, with a control unit, to the center position. A signal is relayed from the control unit to a control valve to urge the plunger toward the center position.

Abstract: Disclosed is a pump, in particular a high-pressure fuel pump, comprising at least one pump element (10) that has a roller tappet (20) inside which a roller (42) is rotatably mounted on a bearing bolt (44) by means of a bearing sleeve (46), said roller (42) rolling off a cam (22) of an input shaft (24). The bearing sleeve (46) is made of a plastic material, especially polyether ether ketone (PEEK) or polyphthalamide (PPA).

Abstract: Electronic documents corresponding to executed paper documents are certified. A certifying agent receives an electronic document and a corresponding paper document that had been executed pursuant to some transaction. The certifying agent compares the information contained in the paper to that in the electronic mortgage document. If the paper adequately corresponds to the electronic document and is otherwise sufficient, then the certifying agent certifies the electronic document so that other parties can reliably engage in transactions involving the electronic document without having to possess or otherwise inspect the executed paper document. Certification involves application of some form of indicia of certification to the electronic document, such as updating the value of a field corresponding to certification in the electronic document and/or applying a digital or electronic signature corresponding to the certifying agent to the electronic document.

Abstract: A batch reverse osmosis system in fluid communication with a fluid reservoir and a method that includes a housing having an inlet valve in fluid communication with the fluid reservoir. The system also includes a pressure vessel having an elongated liner, a membrane disposed within a second end of the liner and having a membrane inlet, a membrane outlet disposed at the second end and a permeate outlet. The system includes a recirculation piston disposed within the first end that defines a fluid volume between the recirculation piston and the membrane adjacent to the membrane inlet. The housing and a plunger disposed within the housing define a chamber. The plunger is coupled to an actuator. The system includes a hollow pipe with a port that is coupled to the actuator. The hollow pipe communicates fluid between the chamber within the housing and the fluid volume within the pressure vessel.

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 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 pump for use with a dispensing unit of a liquid hot melt adhesive system, dispensing units including the pump, and a method of operating a pump for pumping a liquid like liquid hot melt adhesive. The pump has a piston movable within a pumping chamber for transferring liquid from an inlet to an outlet. A valve body, which is resiliently biased relative to the piston, is moved out of contact with the inlet when the piston moves in a first direction and into contact with the inlet when the piston moves in a second direction. When the piston is moved in the first direction, the resilient biasing actively lifts the valve body out of contact with the inlet for overcoming any attractive adhesive force acting between the valve body and inlet.

Abstract: A valve for a gas-driven motor and a valve assembly and reciprocating pump incorporating the valve are provided. The valve includes a shiftable valve for alternatively supplying a motive gas through first and second supply ports to opposed first and second power pistons in opposed motive gas chambers, respectively, and for effecting alternating exhaust of said chambers. The shiftable valve has a front face with a valve projection located thereon and a rear face with a valve projection located thereon.

Abstract: A pinch mechanism, which can be used as part of a pump, includes a deformable tube (10) enclosed within a body (11) which has a first chamber (11a). The deformable tube (10) defines a flow passage. A second chamber (19) is coupled via passage (17) to the first chamber (11a). A piston (20) is located within the second chamber (19) and movable between first and second positions. Upon moving to the first position a pressure increase occurs in the first chamber (11a). Upon moving to the second position a negative pressure is created in the first chamber (11a). A vent means (25) is located at a point during movement of the piston (20) between the first and second positions which enables pressure equalisation within the second chamber (19) to occur.

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 invention concerns an assembly for transferring fluid (13) between a first site and a second site, comprising: a winch (40) for the first site (10) whereon is wound a suspension cable (17) designed to be stretched between the two sites (10, 11) and which is adapted to subject the cable to constant tension; a support (14) for the first site and for storing in suspension rigid pipe sections (15) mutually articulated via articulating sections (16) with rotary bends and joints, so as to shift from a storage position wherein the pipe sections (15) are suspended accordion-like to the support (14) to a stretched position between the two sites (10, 11) by being suspended to the cable; and means for coupling (22) some of the articulating sections (16) to the support (14) or to cable (17) depending on the length of the cable stretched between the two sites (10, 11).

Abstract: A hydraulic amplifier system for an ultra-high pressure liquid chromatography system. The hydraulic amplifier system includes a hydraulic cylinder comprising a primary piston chamber in which a primary piston is disposed and a secondary piston chamber in which a secondary piston is disposed. The cross-sectional area of the primary piston is larger than the cross-sectional area of the secondary piston. The difference in the cross-sectional areas of the pistons creates an amplification of the pressure in the primary piston chamber and a reduction in flow rate.

Abstract: A pump has a main unit (18) for pumping a transferred liquid which is actuated by an secondary unit (20) which pumps a working liquid. The secondary unit (20) has a hub (64) which is rotably mounted in a housing (16). The hub has a cylindrical guiding surface (SG) which is rotatable in the housing. A shoulder (FE) axially positions the hub in the housing. The guiding surface and shoulder cooperate with rotation guiding and axial positioning elements on the housing. The hub connects to a swashplate (62) which actuates a piston (54).

Abstract: The transfer device between a jib including at least one pipe section (54a, 54b) fixed to the jib (12) and a coupling, comprises a system of concertina or deformable diamond-shaped type articulated pipe segments and actuated by cable, at least one pipe section (24a, 24b) connecting to the coupling means. Each section fixed to the jib or connecting to the coupling is connected to one end of the system by a bend and rotary joints (53a, 53b), the bend being fixed to a support (51, 52) suspended from the jib. Each end of the system is fixed to a support (74a) movably mounted in rotation by a bearing (78a) on the bend support to which the end is connected, concentrically with the joint (72a) connecting the end to the bend. The invention applies in particular to the transfer of liquefied natural gas from a marine platform to an oil tanker.

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 gas driven pump controls the process fluid pressure within a filtering and dispensing system. A pressure controller in the pump controls gas pressure within an enclosed chamber in the pump. The gas chamber is adjacent a floating piston that rests atop a layer of incompressible fluid in a fluid chamber. The incompressible fluid connects to a diaphragm head. As the gas pressure is increased, the floating piston will transmit that pressure through the incompressible fluid that then forces a relative displacement in the process fluid flow. A feedback system used in conjunction with the gas driven pump controls the gas pressure in order to regulate the process fluid flow.In addition, a positive displacement compensator can be used in conjunction with the gas driven pump in order to further regulate the process flow.

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: For a hydraulically driven diaphragm pump with a diaphragm consisting of at least two individual layers, these layers are clamped at least in their central area between a coupling part on the feed area side and the hydraulics area side and are thus mechanically linked with one another. The coupling parts are also connected with a relay valve of a leak replenishment system which is attached in the pump body in a moveable manner.

Abstract: On a hydraulic diaphragm pump with a diaphragm including at least two individual layers, a dimensionally stable reinforcing element that moves together with the diaphragm and is kept in contact with the diaphragm is provided in the central area of the diaphragm. The inlet and outlet channels of the diaphragm pump open into the delivery chamber radially within the reinforcing element at least for the most part so the channels are covered accordingly by the reinforcing element.

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 hydraulically driven membrane pump, particularly a high pressure membrane pump, having a membrane which is held on its edges by a clamp between a pump housing and a pump cover, which membrane separates a pumping space from a hydraulic compression space, and may particularly be a metal membrane. A hydraulic membrane drive in the form of a reciprocating displacement piston is slidably mounted in a cylindrical bore in the pump housing, which piston is disposed between the compression space and a reservoir space for the hydraulic fluid. A leak replenishment device including a snuffle link in the form of a connecting channel between the compression space and the reservoir space, which snuffle link is normally closed off by an underpressure-controlled spring-loaded snuffle valve.

Abstract: Insulation is provided in the form of wall insulation, piston or diaphragm insulation and/or piston rod and/or diaphragm washer insulation to increase the temperature in the working air chamber of an air motor of the piston or diaphragm type to reduce the formation of ice on exhaust.

Abstract: A diaphragm-type pump includes a disk-like diaphragm made of an elastic material which is held between an upper housing and a lower housing. In this diaphragm-type pump, the diaphragm, which has a flat shape before it is mounted in the pump, is bent along a diaphragm stopper and mounted in the pump. Consequently, an urging force is constantly applied to the diaphragm in such a direction as to press it on the diaphragm stopper. The diaphragm is deformed in response to reciprocation of a plunger, and when the plunger reaches the bottom dead center and a cylinder chamber is decreased in pressure, the diaphragm is pressed on the diaphragm stopper by the urging force toward the diaphragm stopper and a feed pressure of a feed pump.

Abstract: A pressure testing apparatus including a twin cylinder accumulator assembly having a first cylinder and a first piston dividing the first cylinder into first and second chambers. The first chamber communicates with a test specimen and contains a first fluid. The twin cylinder accumulator assembly also includes a second cylinder coaxial with the first cylinder and a second piston which divides the second cylinder into third and fourth chambers and which is connected to the first piston by a common piston rod. The fourth chamber communicates with a hydraulic pressure unit and is supplied with alternating high and low pressures to cyclically pressurize the first fluid in the fourth chamber and the test specimen communicating therewith. A switch actuator is mounted on the piston rod for actuating first and second proximity sensors to monitor piston rod movement.

Abstract: A pump system includes a displacement pump whose oscillating fluid pressure variations are connected to drive a membrane pump. The membrane pump in turn oscillates fluid in a fluid-filled vertical pipe connected to a fluid-filled commuting pipe. The displacement of fluid in the commuting pipe induces intake of a fluid to be pumped into the commuting pipe during an intake portion of the oscillation and also induces expulsion of the fluid to be pumped during the remaining portion of the oscillation. The commuting pipe is made long enough so that fluid drawn in during the intake portion does not pass into the vertical pipe but stays in the commuting pipe. A heat exchanger about the vertical pipe dissipates heat that may be passed to the fluid therein by conduction or convection.

Abstract: A high pressure fuel injector system including a high pressure fuel pump useable with a pressure booster, a pressure stabilizer with a high speed tandem actuated distributor and a fuel having a fuel injector with high pressure fuel admisstion passages and low pressure fuel return passages with a needle valve hydraulically operated by high pressure fuel from the high pressure fuel admission passage by a distributor valve which selectively directs a hydraulic pressure fuel against one side or the other of a piston body forming part of the needle valve whereby the needle valve is urged to a position closing discharge orifices or position opening discharge orifices the distributor valve being controlled by an electronic actuator wherein the injector system is designed with unique floating valve pistons in the components, the components being useable separately or together in the integrated systems preferred for high pressure, high speed operation.

Abstract: In a hydraulically driven diaphragm pump, which is provided with a diaphragm clamped on the edge which separates a delivery chamber from a hydraulic chamber, the hydraulic chamber being subdivided into a diaphragm work chamber and a piston work chamber connected therewith via at least one connecting duct, a hydraulic diaphragm drive in the form of an oscillating displacement piston which is displaceable in the pump body between a reservoir for the hydraulic fluid and the piston work chamber, and with a diaphragm position-controlled leakage makeup device which comprises a control valve with a control slide displaceably guided in the zone of the connecting duct between diaphragm work chamber and piston work chamber, which slide opens--in the suction stroke end position of the diaphragm--a connection from the reservoir to the piston work chamber, the arrangement is made in such a way that the control slide (19) of the leakage makeup device is provided at its two ends with devices (31; 20) for stroke path limitat

Abstract: A diaphragm pump includes upper and lower pump bodies clamping a diaphragm therebetween which separates a driving fluid chamber in the upper body from a pump chamber in the lower body, each body having gripping ridges surrounding the chamber; a driving fluid reservoir in the upper pump body; an outlet check valve having a seat, a closure member and a spring to urge its closure; drive means for alternately pressure loading and unloading the driving fluid chamber; a diaphragm having a central body portion connected to an annular clamping portion by annular webbing; a protruding annular rib inside of the ridges, and sized to bite into the diaphragm before the ridges when the bodies are clamped together; means for adjusting the size of an opening between the driving fluid reservoir and the driving fluid chamber; means for adjusting the distance that the closure member can move away from the seat; a piston assembly including piston received within a cylinder having an upwardly facing sealing surface and adapted to

Abstract: A compressor (2) uses lower pressure compressed air from a compressed air supply (4, 6) to automatically create higher pressure compressed air. This compressor includes a pressure intensifier (8) having a piston assembly (16) sized for reciprocal movement between forward and retracted positions. The first cylinder (20) has an inlet (10) coupled to the air supply. The second cylinder (22) has an outlet (14) and a supplemental inlet (38). A first check valve (40) couples the supplemental inlet to the ambient atmosphere to permit fluid to flow through the first check valve and into the second cylinder through the supplemental inlet, but not the reverse. A second check valve (42) is coupled to the outlet and permits fluid to flow from the second cylinder, through the outlet and through the second check valve. The compressor also includes means for venting (48) the first cylinder to atmosphere when the piston assembly is in the forward position to permit the piston assembly to return to the retracted position.

Abstract: The invention relates to an improvement in variable capacity diaphragm pumps. According to the invention, the piston is driven by a cam fast with the wheel of a speed reducing gear pair, the eccentric/wheel assembly rotating idly on a fixzed shaft of which the axis is perpendicular to the axis of the piston, the piston terminating in a U-shaped shank of which the wings are perpendicular to the axis of the piston and spaced apart by a length slightly greater than the diameter of the eccentric, and of which the base is perpendicular to said fixed shaft and is provided with a longitudinal groove parallel to the axis of the piston which is traversed by the fixed shaft, the eccentric being housed between the wings of the shank. The invention is more particularly applicable to the manufacture of diaphagm pumps.

Abstract: Apparatus for simultaneously pumping two or more different liquids to a spraying device has a pair of discrete diaphragm pumps for each liquid. The pumps of each pair are connected in parallel and operate alternatingly so that one pump delivers a metered quantity of liquid while the pumping chamber of the other pump receives a metered quantity of the same liquid and vice versa. The capacities of pumps of at least one pair are adjustable in a simultaneous operation, and all pumps are operated by a common prime mover.

Abstract: A diaphragm plunger pump comprises a housing, element forming a pump chamber associated with the housing, a plunger working chamber arranged to be filled with hydraulic fluid during operation, a sealingly clamped diaphragm separating the pump chamber from the plunger working chamber, a plunger sealing displaceable in the plunger working chamber for alternating stoke plunger working chamber for alternating stroke deflection of the diaphragm, a supply chamber for hydraulic liquid and connectable with the plunger working chamber, a valve arranged to connect the supply chamber with the working chamber, the plunger having a central opening provided with a valve seat and serving for communication of the plunger working chamber with the supply chamber, the valve having a valve body which cooperates with the valve seat and is coaxially displaceable relative to the latter, element for sealingly pressing the valve body against the valve seat, and abutment element arranged to lift the valve body from the valve seat when

Abstract: A pressure intensifier for a fluid comprises at least three piston assemblies disposed along mutually parallel axes equiangularly disposed with respect to a central axis of the intensifier and radially equidistant therefrom. Each piston assembly has two opposed high pressure cylinders and low pressure cylinders. Fluid is supplied to the low pressure cylinders and discharged through a low pressure valve operatively coupled by a swash plate to the pistons of each assembly so as to be driven thereby. A high pressure collector, optionally in the form of a closed circuit, is provided for receiving high pressure fluid from the high pressure cylinders.

Abstract: A proportioning pump with tandem diaphragm pumps each having a pumpage chamber connected with a source of supply and a mixer and dispensing nozzle, a piston pump for operating each of the diaphragm pumps, a common eccentric drive for the pistons of the piston pumps, the piston pumps having cylinder wall sleeves extending into the hydraulic fluid reservoir, the sleeves having refill ports therethrough communicating between the pump chamber and the reservoir, one of the sleeves being longitudinally adjustable, a double threaded rotary control for the longitudinal adjustable cylinder wall sleeve, bypass pressure relief valves and passages for the hydraulic fluid from the pump chambers returning fluid to the reservoir in the event of excessive pressure, and the pump motor having a variable speed drive for widely varying the speed of the pump.

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 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: A fuel injection pump for an internal combustion engine including a rotor located in a housing, a free piston movably mounted in an axial bore in the rotor, two pressure chambers defined by an inner wall surface of the axial bore in the rotor the free piston, and two solenoid valves for supplying fuel to the pressure chambers and a sensor for sensing a displacement of the free piston in an axial direction.

Abstract: A hydraulically actuated pump of the piston-diaphragm type for pumping a liquid such as paint through an airless spray gun having a flexible hose which is connected to the pump outlet downstream of the outlet check valve and which has a volumetric capacity many times the displacement of the diaphragm actuating piston to constitute an elastically expansible and contractible pressure storage vessel.

Abstract: A diaphragm pump comprises a body defining a chamber in which a diaphragm is arranged to divide the chamber into a drive chamber and a pump chamber. The pump chamber has an inlet and an outlet for fluid to be pumped, each of the inlet and outlet being provided with a one-way valve. The drive chamber has an inlet for driving fluid and the inlet is provided with a valve which is open under normal operating conditions of the pump. The valve is arranged so that, if a high pressure persists in the pump chamber when the pressure in the drive chamber is relieved causing the diaphragm to expand, the diaphragm will contact the movable valve member of the valve to move it to a position closing the inlet opening so that the drive chamber is isolated from the drive fluid pressure variations while the abnormal pressure subsists in the pump chamber.

Abstract: A diaphragm pump includes a pump chamber, a pressure fluid chamber, a diaphragm partitioning the interior of the pump into the pump chamber and the pressure fluid chamber, a cylinder communicating with the pressure fluid chamber, and a plunger reciprocable within the cylinder. The pressure fluid chamber or the cylinder communicates with a pressure fluid reservoir via a pressure regulating valve adapted to open when the pressure in the pressure fluid chamber is too high, and a valve adapted to open before the pressure in the pressure fluid chamber is too low, and to close when the pressure is restored to a given pressure level.

Abstract: A piston diaphragm pump includes a driving fluid chamber and a driven fluid chamber. A flexible diaphragm separates the fluid chambers from one another. An electric motor drives a reciprocating piston through a crankshaft, and the piston moves in the driving fluid chamber from a forward position to a rearward position on a suction stroke and from the rearward position to the forward position on a pressure stroke. An inlet passage extends between a crankcase and the driving fluid chamber, and a normally closed inlet valve in the inlet passage is opened by a cam on the crankshaft when the piston reaches a predetermined position on its suction stroke. The driving fluid in the driving fluid chamber drives the flexible diaphragm back and forth, and the back and forth movement of the diaphragm pumps the driven fluid into and out of the driven fluid chamber.

Abstract: A high pressure pump in which at least one reciprocatingly driven piston acts on a hydraulic fluid communicating with one side of a diaphragm, the other side of the diaphragm communicating with a fluid to be displaced by the pump. The diaphragm is made of elastomeric material, and is relatively thick so that it is substantially self-restoring on the return stroke of the piston even in the event of total blockage of the supply of fluid to be displaced.

Abstract: An apparatus for reciprocating a piston in a diaphragm pump wherein the piston alternately pressurizes and relieves an oil filled chamber having a diaphragm separating the chamber from a liquid pumping chamber, the invention comprising a bearing shoe interposed between the piston and driving crank shaft, wherein the shoe has oil ports for lubricating and for relieving excess fluid volume from the oil chamber during each piston stroke.

Abstract: A combination pump-injector device directly mountable upon the cylinder heads in an internal combustion engine. The device includes a housing with a spring biased cam operated constant stroke reciprocating piston therein and an unrestrained free-floating plunger means mounted between the piston and an injector valve which communicate directly with the engine cylinder. A quantity fuel metering device transfers a predetermined amount of fuel to a chamber communicating between the free-floating plunger and the injector valve and tends to move the free-floating plunger toward the reciprocating piston. A secondary fluid supply communicates with and fills a second chamber disposed between the piston and the free-floating plunger and counteracts the tendency for the free-floating plunger to move toward the piston. The secondary fluid chamber includes first and second fluid escape and entry ports which determine the beginning and termination of an injection cycle.

Abstract: A diaphragm pump having a pump chamber divided into two portions by a diaphragm of elastomeric material which is generally of hemispherical shape and clamped at its periphery in the pump chamber. The portion of the chamber including the interior of the diaphragm communicates with a cylinder in which a piston is reciprocated by rotation of a drive shaft. The pump chamber includes inlet and outlet non-return valves for the fluid to be pumped, is detachable as a unit from a housing containing the piston and cylinder and is positioned below a normally horizontal plane containing the axes of the cylinder and drive shaft.