Abstract: The linear pump (10,110) includes a housing (12, 112) and either two (20,22) or one (120) flexible bladders each within a pump housing and interconnected to respective end caps (30, 32, 130, 132, 134, 136). Upon movement of a movable end cap relative to a stationary end cap, the volume in each bladder may be variably controlled to pump blood or another selected fluid. Linear movement of the end caps may be controlled by an attractive or repulsive force between end caps. The pump (110) with a permeable bladder (120) may be used to pump wastewater.

Abstract: An oil supply unit of a linear compressor including: a well-closed container filled with oil; a frame installed within the well-closed container; a cylinder fixed at the frame; a piston inserted, in the cylinder and being linearly and reciprocally moved by a linear motor; an oil cylinder fixed at the lower portion of the frame so as to be put in the oil filling the well-closed container, and being vibrated in the horizontal direction according to the reciprocal movement of the piston; an oil piston inserted in the oil cylinder in a manner of dividing the inside of the oil cylinder to a suction space and a discharge space that are communicated to each other, and being vibrated in the horizontal direction; an oil suction installed at the outer side of the suction side of the oil cylinder, for opening and closing the suction side of the oil cylinder; an oil discharge valve installed at the outer side of the discharging side of the oil cylinder, for opening and closing the discharging side of the oil cylinder; an

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: In a reciprocating compressor in which a suction valve (21) of a leaf valve is placed between a valve plate (16) and a cylinder block (12) to open and close a suction port (18) formed in the valve plate, the suction valve is previously bent to open the suction port in an initial state when the compressor is stopped. The cylinder block has a cylinder bore (11) with which the suction port is communicated and into which a piston (17) is inserted. When the piston performs reciprocating movement in the cylinder bore, the suction valve opens and closes the suction port in response to the reciprocating movement in a pulsation reducing manner.

Abstract: A reciprocating piston compressor is provided, including a crankcase having a cylinder, the cylinder having an opening in an exterior surface of the crankcase. A valve assembly including a suction leaf plate covers the cylinder opening. A flexible suction leaf valve is defined by a slot in the suction leaf plate, and the suction leaf valve includes a base integral with the suction leaf plate and a tip opposite the base. The slot has a width which is reduced from a maximum distance at the base to a minimum distance at the tip.

Abstract: An axial plunger pump includes a shaft having a swash plate effecting swing motion and transmitting driving force from the outside, plungers reciprocate by the swing motion of the swash plate. A cylinder block has cylinders formed so as to open on the side of the swash plate, with the plungers inserted therein. Passages in the block supply refuel to the cylinders. A body combined with the cylinder block encloses the swash plate. Sealing members are arranged between the plungers and the cylinders on the swash plate side of the passages formed in the cylinder block for sealing gaps between the plungers and the cylinders, respectively.

Abstract: In a fuel injection pump, flat sections are provided around a connecting segment located between an inner wall surface of a pump housing defining a fuel pressurizing chamber and an inner wall surface of a fuel intake passage as well as a connecting segment located between the wall surface of the pump housing and an inner wall surface of a fuel discharge passage 15 to spread stresses concentrated in upper and lower intersecting points of each connecting segment over an entire periphery of the connecting segment. As a result, the strength of the fuel injection pump is improved to allow use of higher fuel injection pressures. Furthermore, the strength of the fuel injection pump is improved without increasing a wall thickness of the pump housing, so that a size of the fuel injection pump is not increased.

Abstract: A piston pump for a hydraulic brake system of a vehicle with slip control. The piston pump has a piston which is received in a bush that is inserted into a cylinder bore of a pump housing that is closed in pressure-tight fashion by a closure part. For simpler assembly, the closure part is connected to the bush by means of a snap or detent connection. As a result, a preassembled unit that can be manipulated easily before insertion into the pump housing is obtained in a simple way.

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 pump of the type comprising a substantially cylindrical body (1) in one piece provided, in its lower part, with a port (11) for admission of a product and with a valve constituted by a cavity (10) containing an element (2) capable of moving between a lower stop (12b) corresponding to the obturation of said admission port (11) and an upper stop (12a) corresponding to the opening of said port (11), and wherein said upper stop (12a) is formed by at least one discontinuous internal projection (12) whose transverse dimension (x) measured in the cavity (10) is at least equal to 20% of the largest transverse dimension of the mobile element (2).

Abstract: A piston pump intended especially for use in a slip-controlled hydraulic vehicle brake system. The piston pump is inserted into a cylinder bore, the piston pump has a piston, a bush, and a closure element that tightly closes the cylinder bore. The closure element is joined radially movably to the bush, for instance via caulking. This joint has the advantage that the piston pump can be assembled into a compact, easily manipulated, and sturdy component unit, and that the closure element and the bush are aligned with one another on being inserted into the cylinder bore.

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: The invention is directed to a piston pump for a hydraulic vehicle brake system. For simple and inexpensive manufacturability, the piston pump embodies an outlet conduit as a groove in a sleeve bottom and a sealing part. As a result, the sleeve and the sealing part can be manufactured in a non-cutting manner by means of forming. Another advantage of letting the outflow conduit into the sleeve bottom is that the outlet conduit is disposed a small distance in the axial direction from a valve seat of an outlet valve, which counteracts noise production.

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: In a radial piston pump (2), which has pump elements (10) arranged radial in the pump housing (7) and which in turn have an inlet valve (11) and an outlet valve (12) activated by the medium, the valves (11, 12) are disposed at the outer side of the pump elements (10) whereby the inlet valves (11) are arranged coaxial relative to the pump piston (13). All inlet valves (11) are connected to a joint intake channel (20) that leads around the outside of the pump housing (7).

Abstract: A suction port of a piston type compressor is formed in the shape similar to a portion of a sector with an apex portion of the sector removed. A distal end portion of a suction valve which can open and close the suction port has a contour line including a distal end forming line extending generally parallel to a distal end line of the suction port, and side lines. A gap between the distal end line of the suction port and the distal end forming line of the suction valve is substantially constant, and a gap between the distal end forming line and the circle of the cylinder bore is substantially constant. The ease of the inflow of a gas when the gas is sucked from the suction port to the cylinder bore is improved.

Abstract: The seat of a suction valve of a reciprocating compressor is modified to limit the area in which an annular oil film can be established between the valve and the valve seat. The seat is configured to limit the oil film from 3% to 33% of the total inlet port opening. In a modified embodiment gas at discharge pressure exerts an opening bias to the suction valve at the end of the discharge stroke.

Abstract: A compressor includes a piston reciprocating in a cylinder bore. The piston draws refrigerant into and discharges refrigerant from a compression chamber, which is formed between the piston and a valve plate. The valve plate has a discharge port connecting the compression chamber to the discharge chamber. A guide passage facilitates the flow of the refrigerant from the compression chamber to the discharge port. The guide passage is defined in the compression chamber when the piston is located at the top dead center position. This decreases pressure losses that would otherwise occur when the piston is near the top dead center position.

Abstract: An electric refrigeration compression, in particular for household refrigerating and deep-internal freezing appliances, including an outer casing, an internal body, a piston displaceable within a cylinder, a first seal, a valve spring, a valve plate provided with a refrigerant suction bore and a valve head, wherein the value plate is provided with two recesses on its side facing the valve spring and is designed so that two laterally outwardly projecting parts of the same spring are inclined and can be inserted in the recesses and clamped therein such that a portion of the remaining surface of the valve spring is movably arranged in a position tightly abutting on the valve plate surfacer facing the interior of the cylinder.

Abstract: The invention relates to a piston pump, in particular for a hydraulic vehicle brake system with slip control. The piston pump (10) has a piston (16), which is received in a bush (26) that is inserted into a cylinder bore (12) of a pump housing (14) that is closed in pressure-tight fashion by a closure part (68). For simpler assembly, the invention proposes that the closure part (68) be connected to the bush (26) by means of a snap or detent connection (72, 80). As a result, a preassembled unit that can be manipulated easily before insertion into the pump housing (14) is obtained in a simple way.

Abstract: In a reciprocating compressor in which a suction valve (21) of a leaf valve is placed between a valve plate (16) and a cylinder block (12) to open and close a suction port (18) formed in the valve plate, the suction valve is previously bent to open the suction port in an initial state when the compressor is stopped. The cylinder block has a cylinder bore (11) with which the suction port is communicated and into which a piston (17) is inserted. When the piston performs reciprocating movement in the cylinder bore, the suction valve opens and closes the suction port in response to the reciprocating movement in a pulsation reducing manner.

Abstract: A compressor including a valve plate held between the body and the head with the interposition of a first and a second flat sealing gasket. The compressor further includes a thin-sheet aspiration valve associated with an aspiration hole provided on the valve plate. The entire valve is accommodated within a recessed area provided on a surface of the valve plate that is turned toward the body of the compressor.

Abstract: A manual air pump includes an outer cylinder having a chamber therein, a head provided to a second end of the outer cylinder and 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 and including a longitudinal hole. An outer piston is attached to an end of the inner cylinder to move therewith. The outer piston includes a passage that is intercommunicated between the longitudinal hole of the inner cylinder and the outlet passage of the head. A piston rod is reciprocatingly mounted in longitudinal hole of the inner cylinder. An inner piston is attached to a second end of the piston rod to move therewith. A handle is secured to a first end of the piston rod to move therewith. A switch member is rotatably mounted to the first end of the outer cylinder and around the first end of the inner cylinder.

Abstract: In a fuel injection pump, flat sections are provided around a connecting segment located between an inner wall surface of a pump housing defining a fuel pressurizing chamber and an inner wall surface of a fuel intake passage as well as a connecting segment located between the wall surface of the pump housing and an inner wall surface of a fuel discharge passage 15 to spread stresses concentrated in upper and lower intersecting points of each connecting segment over an entire periphery of the connecting segment. As a result, the strength of the fuel injection pump is improved to allow use of higher fuel injection pressures. Furthermore, the strength of the fuel injection pump is improved without increasing a wall thickness of the pump housing, so that a size of the fuel injection pump is not increased.

Abstract: A piston-driven oil pump mechanism constructed to simplify structure and reduce parts for increased compression efficiency but drastically reduced generating of noise, the mechanism comprising: an oil pump cylinder additionally mounted at one side of a cylinder block formed with a cylinder where a piston is reciprocally driven by explosion in a combustion chamber; an oil pump piston reciprocally driven in the oil pump cylinder by a crank shaft where reciprocal motion of the piston is changed rotary motion; an oil drainage outlet so formed to communicate with an oil gallery above the oil pump cylinder; an oil suction inlet formed adjacent to the oil outlet above the oil pump cylinder for connection to an oil pan; and oil suction and oil drainage valves openably and closeably actuated by a valve train for opening the oil suction inlet when the oil pump cylinder is downwardly actuated to block the oil drainage outlet and for closing the oil suction inlet when the oil pump cylinder is upwardly actuated to open th

Abstract: Improved membrane valve for transferring fluids or gases in hermetic or semi-hermetic compressors, including a method and system for manufacturing a membrane valve and a membrane valve with applications for use in several motors, particularly in hermetic or semi-hermetic compressors which use, as a refrigeration fluid, an appropriate type of gas thus promoting the refrigeration physical affect. The above mentioned gas is to be transferred from one chamber to the other, according to a pre-determined frequency, when utilized in conjunction with a piston. A body and a membrane are produced from substantially thin metallic plates separately in accordance to an available process and subjected to rounding in order to eliminate live comers, and then juxtaposed thus composing the valve, with the above mentioned membrane on one side, fitted to the body which is fixed through a connection process and, on the other side, left free to oscillate, thus allowing the passage of a fluid such as a refrigeration gas.

Abstract: A variable displacement compressor has a suction chamber, a discharge pressure zone and a bleeding passage. The bleeding passage conducts refrigerant from a crank chamber to the suction chamber. A control valve has a valve chamber and a valve body. The valve chamber forms a part of the bleeding passage. The valve body adjusts the opening amount of the bleeding passage. An adjuster rod urges the valve body in one direction in accordance with the discharge pressure. The adjuster rod is movably supported by a guide hole. A passage is formed between the adjuster rod and the guide hole to draw refrigerant gas from the discharge pressure zone to the crank chamber. This construction permits the compressor to quickly change its displacement. The compressor of this structure is suitable for mass production.

Abstract: A compact pump composed by combining a cylinder into which a diaphragm portion is to be inserted, a case which accommodates a driving portion for driving the diaphragm portion and a valve housing, and clamping and fixing a combination of the members with a spring.

Abstract: An axial plunger slurry pump comprises a pump body, a sloping cam plate, a swashplate, cylinders, plungers and a pump head. Each of the plungers comprises a plunger body with a rubber piston positioned in its front end and being able to slide over it, and an oil receiving gap communicating with an oil passage disposed between two facing end surfaces of the plunger body and the rubber piston. There are check valves each of which is provided in an oil passage between a ball of each of two-ball links, which ball is coupled with the swashplate, and the swashplate. Each of the cylinder and the plunger body are fitted together by means of a half-and-half locating pad, a cylinder sleeve, a pressing cap, and a locking device. The pump may be used widely in drilling, electric power, mine, building, and metallurgy, etc., for conveying mud, mortar, ore pulp, coal pulp, concrete, etc.

Abstract: A refrigerant compressor, for compressing a refrigerant gas and delivering the compressed refrigerant gas toward an external refrigerating system, which has at least a rear housing provided with a rear discharge chamber defined by a partition wall and a rear discharge valve assembly including a rear discharge valve element and a rear retainer element coated with a rubber material, the partition wall having an endmost first end surface holding a base portion of the rear discharge valve element and a base end portion of the rear retainer element, a tapered surface portion extending toward a rear direction from the endmost first end surface, and a second end surface extending from the rear end of the tapered side surface to be parallel with the first end surface, the tapered surface portion and the second end surface defining a cavity and a support portion to prevent an uncontrolled deformation of controlling portions of the retainer element which control an amount of opening of the valve portions of the rear di

Abstract: Electric compressor comprising a piston provided with a respective head and a valve plate mounted between the head and the body of the cylinder and provided with a gas suction port, the head being provided with a protrusion adapted to be intermittently introduced in the suction port substantially in the top dead-center position of the piston. The piston is provided externally, in the portion thereof which is opposite to the head side, with a recess that is accessible from the outside and is orientated towards the inner volume of the piston, the recess penetrating the body of the piston down to a depth which is at least equal to the height of the protrusion above the plane of the head.

Abstract: A hand pump includes a cylinder, a head mounted to a first end of the cylinder and including a compartment communicated with a bore of the cylinder, and a piston rod including a first end reciprocatingly received in the bore of the cylinder and a second end beyond a second end of the cylinder. The piston rod includes a chamber for receiving a gas container therein. An automatic inflation device is attached to the second end of the piston rod and includes a valve engaging arrangement to be optionally engaged with a valve of an object to be inflated. A pin is provided to open the gas container in the chamber of the piston rod such that gas from the gas container is guided to an outlet of the automatic inflation device. A manual inflation device is mounted in the head for optionally engaging with the valve of the object to be inflated. The automatic inflation device is capable of acting as a handle to proceed with manual inflation to the valve of the object to be inflated via the manual inflation device.

Abstract: A seal assembly for a high pressure vessel. The pressure vessel can include a first material and can have a face with a bore extending through the face such that the bore has an edge at an intersection of the bore and the face. A check valve, including a second material, can extend into the bore and a seal seat, including a third material different than at least one of the first and second materials, can be positioned between the pressure vessel and the check valve body to reduce galling and/or fretting of the pressure vessel and check valve body.

Abstract: A piston pump which is intended particularly for use in a slip-controlled hydraulic vehicle brake system. To increase a pumping volume of the piston pump at low pumping pressure, the piston pump includes a body embodied preferably as an annular body which is attached axially displaceably to the piston. The body increases a cross- sectional area of the piston and is axially acted upon by a spring element. At low pressure, the piston pump pumps with the entire cross-sectional area of the piston and the body while conversely at a higher pumping pressure, the body is held back counter to the force of the spring element and does not move together with the piston so that then the piston pumps only with its own cross-sectional area. The piston pump of the invention has the advantage of improved pressure buildup dynamics when the pumping pressure at the onset of pumping is low.

Abstract: A pumping device includes a main body having a passage defined therein and communicated with an air source. A retainer is slidably received in the main body and includes a chamber communicated with the passage of the main body. A nozzle is received in the chamber of the retainer and includes a nozzle passage communicated with the chamber. A plastic nozzle head is securely mounted in the main body and includes a valve chamber defined therein and communicated with the nozzle passage. A lever is provided for switching the retainer between a first inoperative position and a second operative position in which when the retainer is switched to the second operative position, the retainer exerts an inward force upon an outer periphery of the plastic nozzle head.

Abstract: A valved piston arrangement for an electric motor driven air compressor includes a motor provided with an output shaft having a semi-cylindrical portion at an outer end thereof, a mount formed with a vertical cylinder and a downwardly extending lug, a transmission mechanism including a circular body and a counterweight fitted in the circular body, and a compression mechanism mounted inside the cylinder and coupled to a coupling rod through a link, whereby the valved piston arrangement for an electric motor driven air compressor can achieve high performance and can draw in air to cool the motor in operation.

Abstract: A tire pump, which is adapted to be secured on a bicycle, includes an elongate mounting frame, a cylinder, a piston, a hinge member, and a lever. The mounting frame has first and second ends. The cylinder has a rear end pivotally secured to the second end, and a front end spaced apart from the rear end and disposed to be proximate to the first end. The piston is disposed to reciprocate within the cylinder so as to pump air out of an outlet in the rear end to inflate a bicycle tire. The cylinder further has a piston rod with a fixed end secured to the piston in the cylinder and a coupling end extending axially and outwardly of the front end. The hinge member includes a fixed knuckle member and a movable knuckle member. The fixed knuckle member is disposed on the coupling end.

Abstract: A piston and cylinder air compressor has an induction reed valve including a flat springy reed having end regions which are tiltably supported to hold the reed in closing relationship with an air induction passage of a valve plate whilst permitting deflection and bending of an intermediate region without bending stress at the end regions the valve plate having recesses permitting accompanying tilting of the end regions.

Abstract: In addition to seating on its valve seat during the combined compression and discharge stroke, the suction valve seats on the structure associated with the valve seat which has at least one shallow recessed area. In seating on its valve seat, the suction valve seats on the structure defining the shallow recesses to trap fluid therein. The recesses serve to reduce the area available for adhesion and the trapped fluid pressure provides an opening bias to the suction valve. If necessary, or desired, restricted communication between the compression chamber and the shallow recess can take place to provide a higher pressure in the recess at the time of transition from discharge to suction.

Abstract: A spring must be engaged and deformed by the suction valve in order for the suction valve to seat. The spring provides an opening bias to the suction valve with negates most, if not all, of the effects of adhesion due to the presence of a thin oil film between the suction valve and suction valve seat when the suction valve is closed. Accordingly, the opening of the suction valve takes place sooner in the suction stroke and is essentially solely responsive to the differential pressure across the suction valve.

Abstract: A variable displacement compressor controls a discharge displacement by changing an inclination of a swash plate (5) depending on a pressure differential between a crank chamber (3) and a suction chamber (13) thereby to change a piston stroke. A first communication passage (18) establishes communication between the crank chamber and the suction chamber. A first orifice (19) is provided in the first communication passage. A second communication passage (20) establishes communication between a discharge chamber (14) and the crank chamber. A pressure control valve (21) open/close controls the second communication passage so as to adjust a pressure in the crank chamber. A third communication passage (22) establishes communication between the discharge chamber and the crank chamber, bypassing the second communication passage. A second orifice (23) is provided in the third communication passage.

Abstract: A motor-driven compressor unit (12) suspended in a hermetic housing (10) comprises a casing (24) which encloses the stator (16) of the electric motor externally and to which the stator is fixed. The casing (24) carries and is fixed firmly to a block (36) of the compressor and further comprises a transverse wall (28) situated at the opposite end to the block. The block (36) and the transverse wall (28) have respective annular seats (56, 60) concentric with the axis of rotation of the crankshaft (46). The annular seat (56) in the block (36) contains a main self-aligning bearing (86) and the annular seat (60) in the transverse wall (28) of the casing (24) contains a secondary self-aligning bearing (64).

Abstract: A piston and cylinder air compressor has a valve plate between an upper end of the cylinder and a cylinder head, the valve plate having a generally diametrically located recess at the inward surface thereof accommodating a suction valve reed, the valves being located above apertures at least to one side of said recess the arrangement being such as to minimize the operating clearance volume of the compressor.

Abstract: A diaphragm or gasket pump is provided with modified outlet valve and/or inlet valve assemblies which enhance the outlet and/or inlet valve effectiveness and provide long, effective valve lives.

Abstract: A compressor has a control valve that adjusts the pressure difference between a crank chamber and a cylinder bore for controlling the inclination of a drive plate. The control valve protrudes outward from the compressor housing. The compressor also has a support protruding outward from the front housing and a leg protruding outward from the cylinder block. The outer ends of the support and the leg extend further from the compressor than the furthest extremity the control valve. Therefore, when the compressor is placed on a flat surface, the support and the leg prevent the control valve from contacting the surface. This protects the control valve from damage during transport and handling.

Abstract: A refrigerant compressor has a reciprocating piston with a projection extending therefrom is disposed in a cylinder. The cylinder has an end wall with a discharge opening operably closeable by a discharge valve. The projection is disposed on an end face of the piston and extends into the opening of the discharge valve when the piston is in the region of its end position. Extending the projection into the discharge valve enables gas remaining in the region above the piston and in the region of the discharge opening to be displaced out of the discharge valve. The projection has an asymmetrical construction with a circumferential wall has a gradient changing along the circumference of the wall. The discharge valve seat and the flow channel in the region of the discharge valve are operably contoured to prevent turbulent flow from occurring when gas is discharged from the discharge valve.

Abstract: An improved delivery valve for a plunger type fuel distribution pump characterized by ease of manufacture, lightness, and enhance performance in achieving both a check valve function and a retraction volume function. Specifically, previous machined constructions utilized a conically configured check valve and machined grooves which in the improved design are replaced by a commercially available high-precision, smoothly finished steel bearing ball element and by lightweight, tubular stem design.

Abstract: The present invention relates to a pump chamber (1) for a pump intended primarily for infusion systems for medical use, said pump chamber comprising walls (21, 28) delimiting said chamber and an inlet (22) and an outlet (23), a part of said walls of said pump chamber being formed by a flexible membrane (40, 90), said membrane being actuatable by a reciprocally movable actuating means (80), thus varying the volume of the pump chamber in accordance with the movements of said actuating means. The membrane (40, 90) has a convex domed shape projecting outwardly from said pump chamber (1) and is made of a resiliently flexible material, the apex of the domed membrane being acted upon by said actuating means, said actuating means having a stroke which may be adjusted to the amount of the dose to be administered. The invention also relates to a valve for a pump chamber.

Abstract: A pump having a simple and compact construction which permits leakage test of the pressure valve both outside and inside the pump housing, and, if necessary, ensures ease of replacement of individual parts, such as replacement of the pressure valve or the valve seat member, if leakage occurs during testing. The peripheral surface of the valve seat member facing the cover has a conical chamfer onto which an annular projection of the cover is movable into sealing abutment and is radially expandable to provide a press fit engagement.