Abstract: A reciprocating pump which is capable of detecting abnormalities in the sucking and discharging of fluid, such as the exhaustion of oil or the clogging of oil on the discharge side, by making use of detecting means which is inexpensive and relatively simple in structure and which can be operated without being detrimentally influenced by the bubbles that may be included in the fluid, while making it possible to minimize the noise generated by external vibrations. In this reciprocating pump, where the sucking and discharging of fluid are effected by making use of a reciprocating member, malfunction-detecting means formed of a piezoelectric element is provided for detecting a pressure fluctuation on a discharge side of the pump, and the pressure fluctuation of fluid being delivered from an discharging port is transmitted via a rigid pressure-receiving member to the piezoelectric element.

Abstract: A refrigerant compressor has a member forming a compression chamber with a discharge port and a discharge reed valve. The reed valve has a valve cover portion at one end for opening and closing the discharge port and a portion at another end that is fixed to the member. A valve restricting plate is fixed to the member forming the compression chamber together with the fixed portion of the discharge valve so as to overlie the reed valve and to restrict the opening amount of the reed valve cover portion. The valve restricting plate has a head portion wider than a middle portion thereof which head portion opposes the valve cover portion of the discharge valve against which it can come into contact A through hole or notch is provided in the restricting plate head portion to provide back pressure flow communication that acts on the cover portion of the reed valve to prevent it from sticking to the valve restricting plate.

Abstract: A compressor assembly including a compressor mechanism, a compression chamber and a discharge chamber. A discharge port provides fluid communication between the compression chamber and the discharge chamber. A valve seat circumscribes the discharge port. A discharge valve member having a valve head, a biasing section and a valve support is provided and may be formed out of a single integral part. The valve head is engageable with the valve seat. A non-threaded coupling member may mount the valve support to the cylinder block of the compressor mechanism. A guide member engageable with the biasing section of the valve member may also be provided. The valve head may include a second concave surface positioned opposite the surface engageable with the valve seat and have an effective area larger than the discharge port area. The valve head and valve seat may each be partially spherical surfaces having a common radius.

Abstract: A unit for pumping fluid, particularly blood, is provided with an enclosure that has two half-shells and an elastic membrane fixed perimetrically to the enclosure in order to divide its space into two parts. One of the half-shells is provided with valves that are located at the opening of two connecting ducts for the intake and delivery of the fluid, and the other half-shell is connected to a line of working fluid that is alternately pressurized and depressurized. The first valve is a disk-shaped sheet made of elastic material. The first valve is in a central position with a support that is fixed to the opening of the first duct for connection to the outside and is suitable to rest at its peripheral region on the support. A second valve is a sheet of elastic material located at the peripheral region of the disk at the opening of the second duct for connection to the outside which lies at the peripheral region of the opening of the first duct.

Abstract: An inleakageproof structure for escape opening of a coil-type compressor. An outer wall face of the fixed coiled body of the compressor is formed with an annular oil groove around the escape opening. The oil groove is formed within a range covered by the valve plate. A valve plate is disposed on the outer wall face of the fixed coiled body corresponding to the escape opening. An oil liquid exhausted from the escape opening is contained in the oil groove. By means of capillarity of the oil liquid in the oil groove, the oil liquid automatically seals a gap between the valve plate and the outer wall face of the fixed coiled body.

Abstract: A restarting device of a pump including a center rod defining fluid delivering chambers and driving chambers 11b and 12b. The restarting device of the pump further includes: a change-over valve 2 for switching a direction for the center rod to move, and a restarting hydraulic circuit 3 which, when a supply of the driving fluid from the change-over valve 2 to the driving chambers 11b and 12b in both sides is stopped, detects the supply of the driving fluid into the driving chambers 11b and 12b in both sides having been stopped and then causes the driving fluid to flow into the change-over valve, thereby restarting the supply of the driving fluid into the driving chambers 11b and 12b.

Abstract: In a reciprocating compressor including a piston slide-inserted into the compression space of the cylinder, having a gas path therein, inducing a fluid into the compression space through the gas path and varying a volume of the compression space while performing a linear reciprocating motion with a mover of a reciprocating motor; a suction valve combined with the front end of the piston detachably and adjusting suctioning of the fluid into the compression space; and a discharge valve combined with the front end of the piston detachably and opening/closing the compression space of the cylinder in the linear reciprocating motion of the piston, a suction valve assembly of a reciprocating compressor includes an elastic member for absorb impact of the suction valve in clash and a combining member consisting of a head portion having a width so as to be overlapped with part of an opening/closing portion of the suction valve or a retainer and a valve seat, and accordingly a reliability of the compressor can be improv

Abstract: A pump includes a cylinder, a piston, a connecting rod, a plug, a nozzle and a fastener. The cylinder includes a first open end and a second open end. The piston is movable in the cylinder. The connecting rod includes a first end connected with the piston in the cylinder and a second end located outside the cylinder. The plug is fit in the first open end of the cylinder. The nozzle is mounted on the first open end of the cylinder. The fastener is used to fasten the nozzle and the plug to the cylinder.

Abstract: A method and apparatus for a pump and a pump control system. The apparatus includes pistons integrally formed in a diaphragm and coupled to the diaphragm by convolutes. The convolutes have a bottom surface angled with respect to a top surface of the pistons. The apparatus also includes an outlet port positioned tangentially with respect to the perimeter of an outlet chamber. The apparatus further includes a non-mechanical pressure sensor coupled to a pump control system. For the method of the invention, the microcontroller provides a pulse-width modulation control signal to an output power stage in order to selectively control the power provided to the pump. The control signal is based on the pressure within the pump, the current being provided to the pump, and the voltage level of the battery.

Abstract: Y-block or right-angular fluid section plunger pump housings have cylinder, suction, discharge and/or access bores which are transversely elongated within transition areas for interface with other bores to provide internal access, stress relief and a reduction in housing weight. A two-piece suction valve spring retainer assembly further reduces stress near the bore interfaces and allows use of a top stem guided suction valve that may be installed without threads in the suction bore. Tapered cartridge packing assemblies facilitate use of a one-piece plunger and also allow packing in such housings to be changed without removing the plunger.

Abstract: The invention relates to a refrigerant compressor comprising at least one piston-cylinder unit and one valve plate that has at least one outlet opening. The piston has a projection which projects into the outlet opening when the piston is located near the upper dead center thereof. The aim of the invention is to increase the efficiency and to reduce the noise level. To these ends, the invention provides that the outlet opening, piston projection, valve plate and piston delimit a flow channel, and provides that the free cross-sectional area of the flow channel is determined by the smallest cross-sectional area of the outlet opening until the piston, during its pressure stroke at least the height (H) of the outlet opening, is located underneath the upper dead center.

Abstract: A Y-block fluid section plunger pump housing has a cylinder bore which is transversely elongated at its intersection with suction and discharge bores to provide stress relief and a reduction in housing weight. A spoked ring valve spring retainer ring further reduces stress near the bore intersection and allows use of a top stem guided suction valve. Tapered cartridge packing assemblies facilitate use of a one-piece plunger in Y-block housings and also allow packing in such housings to be changed without removing the plunger.

Abstract: A high pressure fuel pump has a plunger that extends through a cylinder and is reciprocally located in a pressurizing chamber. The plunger is reciprocated by a lifter and changes the volume of the pressurizing chamber to pressurize fuel in the pressurizing chamber. A seal member seals the cylinder from the lifter to prevent fuel that leaks from the pressurizing chamber from being mixed with lubricant that lubricates the lifter. A support to which the seal member is attached is formed separately from the cylinder. The support is fixed to the cylinder with the plunger extending through the support.

Abstract: A bi-directional fluid valve apparatus comprising a valve member adapted to co-act with an annular shoulder at the end of a fluid bore, the valve member having two axial ends. A flat surface on a first end having a diameter greater than that of the shoulder is positioned with the flat surface abutting the axial end surface of the shoulder. At least two axially extending and circumferentially spaced apart ribs are on the second axial end thereof, each of the ribs terminating in an end surface. The ribs are positioned so that the end surfaces are in axial alignment with, and spaced a preselected distance from, the axial end surface of the shoulder. Hollow coil spring means are positioned within the recesses in register with the bores, and having a first end engaging one of the shoulders, and a second end engaging the at least three circumferentially spaced apart ribs and the second axial end of the valve member.

Abstract: A dual stage compressor for use with condensable fluids comprising a condensable fluid expansion stage in fluid and thermal communication with a condensable fluid compression stage wherein the condensable fluid expansion stage comprises a compressor head/heat exchange including a fluid expansion nozzle disposed in operative relationship relative to an condensable fluid expansion chamber formed therein and the condensable fluid compression stage comprises a reciprocating compression piston movable between a first and second position disposed within a compression cylinder having an intake port and an intake valve movable between a first and second position to selectively control fluid flow from the condensable fluid expansion chamber to the interior of the compression cylinder and an exhaust port and an exhaust valve movable between the first and second position to selectively control fluid flow from the compression cylinder such that when the reciprocating compression piston moves from the first to second posi

Abstract: A compact pump has a pump chamber, inlet and outlet channels communicating with the pump chamber, and a pair of check valve units between the pump chamber and the inlet and outlet channels. Each check valve unit has a thin film check valve membrane, and a check valve body with a channel opened and closed by the check valve membrane due to a pressure difference.

Abstract: A piston pump having a piston axially movable against the force of a spring within an operating chamber connected via check valves to an operating cylinder and a hydraulic medium supply. A section of the piston that extends into the operating chamber has a reduced diameter extension which extends from a shoulder of the piston that delimits the operating chamber. The extension includes a thickened free end having a sealing surface facing the shoulder. A valve disk is located and guided on the extension in a gap between the shoulder and sealing surface and is capable of axially reciprocating movements thereon. The valve disk is provided with openings which provide a passageway for hydraulic medium from the operating chamber to a second check valve. The openings are blocked when the valve disk abuts the sealing surface.

Abstract: A liquid pump for pumping groundwater samples from small diameter sub-terrain wells, comprising a tubular casing having inlet apertures, a top cap provided with a fluid communication port and a liquid outlet port, a top bladder mandrel secured to the top cap, a mandrel sealing member disposed in a lower end of the casing, a bottom bladder mandrel secured to the mandrel sealing member, and a flexible bladder extending between the top bladder mandrel and the bottom bladder mandrel and defining a liquid chamber for receiving the liquid therein and a fluid chamber for receiving a fluid under pressure therein that surrounds the liquid chamber, with the bladder disposed therebetween. The fluid chamber is in fluid communication with the fluid communication port connected to a source of the actuating gas, while the liquid chamber is in one-way fluid communication with the liquid inlet and the liquid outlet port.

Abstract: The present invention relates to microfluidic systems, including valves and pumps for microfluidic systems. The valves of the invention include check valves such as diaphragm valves and flap valves. Other valves of the invention include one-use valves. The pumps of the present invention include a reservoir and at least two check valves. The reservoir may be of variable volume. The present invention also relates to a flexible microfluidic system. The present invention additionally relates to a method of making microfluidic systems including those of the present invention. The method includes forming a microfluidic system on a master, connecting a support to the microfluidic system and removing the microfluidic system from the master. The support may remain connected to the microfluidic system or the microfluidic system may be transferred to another substrate. The present invention further relates to a method of manipulating a flow of a fluid in a microfluidic system.

Abstract: A compressor assembly including a housing, a compression mechanism disposed in the housing and having a discharge port, and a discharge check valve assembly. Gas substantially at suction pressure is received into the compression mechanism, compressed and discharged substantially at discharge pressure from the compression mechanism through the discharge port. The discharge check valve assembly has at least one elongate guide pin extending from the compression mechanism and a valve plate disposed about the guide pin. The valve plate has a closed position at a first position along the guide pin in which the valve plate covers the discharge port and an open position at a second position different than the first position along the guide pin in which the valve plate does not cover the discharge port. Gas substantially at discharge pressure and having been discharged from the compression mechanism is substantially prevented by the valve, in its closed position, from reentering the discharge port.

Abstract: Disclosed is a piston pump having a pump housing with a cylinder head comprised of a first plate and a second plate. The plates which rest against each other and are screwed to the pump housing, have a first conduit which carries low-pressure fuel and leads to a first check valve disposed between the two plates. The check valve communicates with a cylinder chamber of the radial piston pump. A second conduit carrying high-pressure fuel leads from this cylinder chamber to a second check valve, which is disposed between the first plate and the pump housing. Seals that are appropriate to the load, in fact low-pressure seals, are provided in the region of the cylinder head that is subjected to low pressure and high-pressure seals are provided in the region of the cylinder head that is subjected to high pressure.

Abstract: Since many valves are used, pressure loss is large, resulting in low reliability of a pump. Even when the period of increasing and decreasing the volume of a pump chamber is long, and a piezoelectric element is used as an actuator that drives a diaphragm, a driving operation cannot be performed at a high frequency, or a proper flow rate cannot be realized under a high load pressure. In accordance with the invention, the combined inertance value of an entrance passage used to make working fluid flow into a pump chamber is smaller than the combined inertance value of an exit passage used to make the working fluid flow out from the pump chamber. A fluid resistance member is provided at the entrance passage in which fluid resistance when the working fluid flows into the pump chamber is smaller than fluid resistance when the working fluid flows out of the pump chamber.

Abstract: A variable capacity type compressor has a swash plate, pistons reciprocating in the cylinder bores, a suction chamber, and a discharge chamber. A check valve arranged in the compressor. The check valve has a valve seat member having a flow passage and a valve seat, a case attached to the valve seat member, and a valve element arranged in the case for cooperation with the valve seat. The case has a communication hole formed therethrough to allow the gas to flow from the flow passage through the communication hole to the outside circuit. The case has a damper chamber formed therein on the back side of the valve element to damp vibration of the valve element.

Abstract: A fuel feeding aggregate for supplying fuel to an internal combustion engine, the fuel feeding aggregate has a housing having a suction-side end and a pressure-side end, a check valve integrated in the pressure-side aid and provided for fuel supply to injection valves, and an additional check valve integrated in the suction-side end in the housing and maintaining a system pressure in the fuel feeding aggregate.

Abstract: A pressure adjusting device has a pumping device, a connector device, and a connection pipe connected to the pumping device and the connector device. The pumping device has a hollow cylinder, a plunger device inserted through the hollow cylinder, a cover covering the hollow cylinder, a check valve and a non-return valve inserted in the cover, and an inhale joint and an exhale joint connected to the cover. The connector device has a stepped post, a threaded rod inserted through the stepped post, a handle bar disposed on the stepped post, and a button disposed on the handle bar and receiving the threaded rod. The threaded rod has a head portion inserted in the connection pipe.

Abstract: A dual stage compressor for use with condensable fluids comprising a condensable fluid expansion stage in fluid and thermal communication with a condensable fluid compression stage wherein the condensable fluid expansion stage comprises a compressor head/heat exchange including a fluid expansion nozzle disposed in operative relationship relative to an condensable fluid expansion chamber formed therein and the condensable fluid compression stage comprises a reciprocating compression piston movable between a first and second position disposed within a compression cylinder having an intake port and an intake valve movable between a first and second position to selectively control fluid flow from the condensable fluid expansion chamber to the interior of the compression cylinder and an exhaust port and an exhaust valve movable between the first and second position to selectively control fluid flow from the compression cylinder such that when the reciprocating compression piston moves from the first to second posi

Abstract: A compressor, comprising: a compression chamber for compressing working fluid within an inside thereof; a discharge port, through which the working fluid flows out from the compression chamber; a valve means for opening or closing the discharge port; a valve seat portion being provided in the discharge port and having a shape of curved surfaces, so that a cross-section area of the discharge port comes to be large from a side of the compression chamber; a valve having a projection portion having a curved surface in contact with the curved surface of the valve seat portion; and a means being provided on a member formed in one body with the valve seat portion, for positioning the valve to the valve seat portion, wherein clearance volume of the discharge port is reduced, so as to improve the performances thereof.

Abstract: A piston-type compressor has a cylinder block in which two or more compression chambers each permits a piston to reciprocate, so as to compress a refrigerant drawn into the cylinders from a suction chamber. The suction chamber is formed in an cylinder head and communicates fluidly with the cylinders through suction ports in a valve plate. Each of the suction ports is opened and closed by a suction reed valve. Each cylinder also has a valve stop portion and recess constructed for stopping movement of the suction reed valve when the valve reaches the open position separated from the valve plate. The valve stop construction includes a concave portion which enlarges an effective passage area thereof, and a stop portion which restricts the bending amplitude of the reed valve to an appropriate degree and is surrounded by the concave portion. By this structure, excess stress to the reed valve may be avoided and the noise and the vibration of the reed valve may be suppressed simultaneously.

Abstract: A manual air pump includes an outer cylinder comprising a chamber therein, a head provided to an end of the outer cylinder, the head including an outlet passage communicated with the chamber for supplying air to an object to be inflated, and an inner cylinder reciprocatingly mounted in the outer cylinder. An outer piston is attached to an end of the inner cylinder to move therewith and includes a passage for communicating a longitudinal bore of the inner cylinder with one of the outlet passage of the head and the chamber of the outer cylinder. A piston rod is reciprocatingly mounted in longitudinal bore of the inner cylinder and an inner piston is attached to an end of the piston rod to move therewith. A handle is secured to the other end of the piston rod to move therewith. The inner cylinder is rotatable relative to the outer cylinder.

Abstract: A reciprocating pump includes a chamber, a reciprocating member arranged to induct a fluid into the chamber and discharge the fluid from the chamber to a delivery side of the pump, and a piezoelectric element attached to the pump and arranged to detect pressure fluctuations on the delivery side of the pump so as to sense any abnormality in the inducting and discharging of fluid.

Abstract: An electromagnetic pump including a housing having an interior fluid containing region, a check valve operatively associated with the fluid containing region for allowing fluid flow in a direction from an inlet toward an outlet and blocking fluid flow in a direction from the outlet to the inlet, an electromagnet carried by the housing located external to the fluid containing region, and a barrier of fluid impervious material for isolating the electromagnet from the fluid. An armature movable in the housing through pumping and return strokes has a pole portion located for magnetic attraction by the electromagnet and has a plunger portion extending from the pole portion. The armature plunger and pole portions have formations crimped together to secure the plunger and pole portions together. The barrier or an end surface of the armature pole portion are shaped to enhance separation of the barrier and armature pole portion at the beginning of the return stroke.

Abstract: In a variable displacement pump, a pump body has an inner surface and is formed with suction and discharge paths communicating with the inner surface. First and second fluid pressure chambers are divisionally formed between the inner surface of the pump body and an outer surface of a cam ring through a seal portion including a swing fulcrum pin. A spring biases the cam ring from the second fluid pressure chamber toward the first fluid pressure chamber. A metering restrictor is provided between the discharge paths. A control valve is connected to the discharge paths formed upstream and downstream, respectively, of the metering restrictor and to the first and second fluid pressure chambers, and is driven by fluid pressures present upstream and downstream of the metering restrictor.

Abstract: A variable displacement pump has a swingable, displaceable cam ring fitted to form a pump chamber together with the outer circumferential surface of a rotor having vanes. Notches are formed by notching to have a substantially V-letter shape in the starting end portions, in the rotating direction of the rotor, of a pump suction opening and pump discharge opening that open to the pump chamber. The notch formed in the starting end portion, in the rotor rotating direction, of the pump suction opening is constituted by a plurality of notched grooves aligned in the radial direction of the pump chamber and having different lengths in the rotating direction of the rotor. Hence, the timing at which the pump suction opening communicates with a pressure chamber formed between the vanes changes in accordance with swing and displacement of the cam ring.

Abstract: A cam case 23 is provided which swingably supports a cam ring 34 for forming a pump chamber 36 from a rotor in a state in which the rotor 33 having a vane 33a is moved to an eccentric position such that a swingable pin 35 axially disposed is used as a fulcrum. A pump body is formed adjacent to the two axial ends of the cam case. Moreover, a front body 21 and a rear body 22 for rotatively supporting a rotational shaft 40 of the rotor are disposed. As one of locating means for locating the two bodies and the cam case when an assembling process is performed, the swingable pin is employed. As another locating means, at least one of joining means for integrally connecting the two bodies and the cam case is a reamer bolt 45A.

Abstract: The present invention relates to a resin-made spring which, although the spring is made of a resin only, has a strength similar to that of a metal-made spring, and in which the strength is hardly reduced with time and can be maintained to a desired degree for a long term, and also to a bellows type constant volume pump which uses such a resin-made spring. The resin-made spring of the present invention has a configuration in which a strip-like PTFE-made sheet is bent in a zigzag manner in a longitudinal direction of the sheet to thereby provide a predetermined swelling curvature R, side faces of bent portions of the predetermined curvature are in close proximity to or in contact with each other, and the bent portions of the predetermined curvature are elastically expandable and contractible by means of heat holding and cooling. Such a PTFE-made spring is used as a spring for a check valve on the side of a tip end portion of a discharge hole of a bellows type constant volume pump.

Abstract: A a cartridge type delivery valve assembly in which a valve seat surface and a valve are integrated in order to assure good seating characteristics in the delivery valve. The delivery valve assembly is formed by fixing together a valve holder provided with delivery holes, a roll valve that is mounted along the internal surface of the valve holder to freely open and close the delivery holes and a valve stopper that fixes the roll valve onto the valve holder and regulates the lift quantity of the roll valve, in an integrated manner using coupling members and the delivery valve assembly thus achieved is mounted in a valve insertion space.

Abstract: An improved discharge valve apparatus for a hermetic compressor which is capable of fixing the retainer based on the elastic force of the elastic protrusions formed in the retainer itself and the shape of the head cover engaged with the retainer, for thus reducing the number of parts and the number of processes. The apparatus includes a head cover, a head engaged with the head cover and having a groove formed in an upper surface of the head, a discharge valve inserted into the groove of the head, a valve spring inserted into the groove of the head for limiting a movement of the discharge valve, and placed on an upper surface of the discharge valve, and a retainer inserted into the groove, and positioned on an upper portion of the valve spring, and having elastic protrusions formed at both sides thereof.

Abstract: Disclosed is a paracentesis valve apparatus and method of using the valve. The valve comprises a valve body having three apertures and a bypass passageway. A movable valve member with truncated end portions moves linearly within the valve body by means of hydraulic pressure alone. Application of negative hydraulic pressure via a syringe withdraws fluid from a body cavity through the valve into the syringe. Application of positive hydraulic pressure to the syringe pumps the fluid through the valve into a receptacle.

Abstract: A subsurface well pump is provided which is resistant to vapor locking. The pump is a reciprocating sucker rod pump which has a top inlet valve, and a means to vent vapors from the barrel of the pump on each stroke.

Abstract: A prior art precompression metering pump which incorporates a differential piston forming part of the pump chamber inlet valve and its outlet valve is difficult to prime, especially in the case of metering paste products. In the improved pump there is disposed between the differential piston and the main piston of the pump a collar consisting of a ring from which project substantially axial tongues which are slightly inwardly inclined and each provided with a head. The collar moves inside the pump body so that normal operation proceeds as if it were not present. To prime the pump, however, the user depresses the collar until it contacts a step on the pump body. The tongues then bend so that their heads, interposed between the two pistons, move the latter apart (by a wedging effect or by a lever arm effect, or by a combination of the two). This is followed by mechanical opening of the pump chamber outlet valve whereby the air initially contained in the pump chamber escapes to the exterior.

Abstract: A subsurface well pump is provided which is resitant to vapor locking. The pump is a reciprocating sucker rod pump which has a top inlet valve which comprises one or more hinged flapper valves.

Abstract: A precompression pump for discharging a liquid in spray form has a first inner compression chamber formed within a pump body between a valve for closing an orifice through which liquid is withdrawn from a storage container and a discharge orifice through which the withdrawn liquid is expelled to a spray-discharge head. The volume of the first chamber is variable by means of a driving piston which is continuously urged by a first helical spring towards a position corresponding to the maximum volume. A second intermediate chamber is located between the first chamber and the discharge orifice, this orifice being shut-off by a needle-valve piston which forms the precompression system. The needle-valve piston is mounted within a moving element but outside the first chamber and urged by a second helical spring to a position of closure of the discharge orifice.

Abstract: A radial piston pump is provided with a plurality of valve/piston cartridges. Each cartridge includes the piston and at least one of the valves connecting the piston to the inlet and outlet passages of the pump. The bearings for the main rotor are pre-loaded using a threadedly adjustable end quill. Once adjusted, the end guill is held in location by a pin or the like. The rotor itself is provided with counterweights to balance the eccentric cam surface. These features allow construction of a pump housing which is substantially a single unit, rather than two pump halves. A significant reduction in the number of machined bores also is obtained.

Abstract: A hydraulic pump is disclosed, characterized in that, in the hydraulic pump including a cylinder body having a cylinder chamber, a suction port and an ejection port, a cam member and a reciprocatingly movable member are provided, wherein oil in said cylinder chamber is ejected when said movable member is pushed into said cylinder chamber by the cam member, a cylindrical piston is slidably fitted into said cylinder chamber, so that the movable member is engaged with the cylindrical piston when it is pushed into the cylinder chamber so shut off communication between the cylinder chamber and the suction port and a valve provided in the ejection passage communicating to said ejection port is opened due to the pressure rise when said movable member is further pushed into said cylinder chamber to eject the oil in the cylinder chamber outwardly.

Abstract: An inner cylinder and a substantially larger outer cylinder are joined as two verticle concentric cylinders. Verticle partitions between the cylinders divide the space between the cylinders into an inlet chamber and an outlet chamber which is substantially larger in volume than the inner chamber. The inner cylinder has a central pumping section positioned between upper and lower valve sections. In the valve section ports extend through the inner cylinder wall to the inlet and outlet chambers. Spring loaded valves close the ports. Tension springs extend across the inlet chamber and compression springs extend across the inner cylinder to close the inlet valves. Tension springs extend across the inner cylinder the close the outlet valves. The elastomeric valve flaps have rigid curved backing members. A piston rod extends through one end cover to move a piston in the central section. An inlet is connected to the inlet chamber and an outlet is connected to the outlet chamber.

Abstract: A reciprocatory piston and cylinder machine particularly suitable for use as a vacuum pump includes a cylinder (17), a cylindrical piston (16) relatively slidably reciprocable within the cylinder (17), and means for substantially sealing the annular space between the piston (16) and cylinder (17) in lieu of oil or other liquid lubricant. The sealing means comprises a sleeve (102) of a low-friction material disposed under circumferential tension, and preferably also under longitudinal tension, on the cylindrical surface of the piston (16). Also disclosed is a reciprocatory piston and cylinder machine of particular prior construction having a one-way valve (42) in an exhaust port (30) ahead of a head portion (24) of the piston (16). The arrangement is such that, as the front face of the piston head portion (24) approaches the closed cylinder end (52), the piston head portion 24 physically moves the one-way valve (42) so as to open the exhaust port (30).

Abstract: A pump and a stress and fatigue resistant pump head, one embodiment of which is useful for a high pressure pump and having a manifold, a valve cartridge, inlet and outlet valves in the valve cartridge, a pump fluid cylinder with a reciprocating plunger therein, a packing cartridge with packing for the plunger. The pump head may exhibit one or more of the following features: a. increased diameter packing cartridge; b. increased length front bushing; c. inclined inlet valve; d. inlet valve spring in valve cartridge on manifold side of valve; e. decreased diameter of high pressure seal of packing cartridge.

Abstract: A piston pump, in accordance with several embodiments, comprises a suction chamber into which fluid medium enters from an inlet line via a suction valve, beginning at the outset of a delivery stroke of the piston pump, without a build-up of intake negative pressure during the delivery stroke of the piston, and is particularly adapted to prevent vapor bubble formation. A reliable pump closure is ensured in the vicinity of the pump outlet, independent of the spring action of a return spring, which bears against the piston, in that any fluid medium entering the suction chamber of the pump contacts the piston in a direction producing reinforcement of the outlet closure pressure. In accordance with preferred embodiments, the piston may be a partially hollow or entirely hollow piston instead of a solid one.

Abstract: A discharge valve retainer for a compressor with at least two arcuately-shaped, annular segments which segments are joined together. By joining the annular segments together, a retainer structure having a very rigid central portion results, thereby reducing stress and fatigue of the retainer. The discharge ports are arranged in an annular fashion and the suction ports are disposed radially inside the annularly arranged discharge ports.

Abstract: An improved type of valve in particular for air compressors is described. The main characteristic of the present invention lies in the fact that it includes a strip in which are formed two substantially U-shape slots passing therethrough, facing towards one another, which define a central portion, two intermediate portions constituted by a respective tongue fixed to a closure plate of a cylinder, and a perimetral portion. In the plate, in correspondence with the central portion and the perimetral portion, there are formed orifices for passage of a fluid, which orifices are alternatively closed or opened by the said central portion and perimetral portion.