Abstract: A pumping apparatus for pumping heavy viscous chemicals and the like. The apparatus has a pump means having means for attachment to a container of the viscous chemicals and the like, and has driving means including a motor and means for detachably connecting the driving means to the pump means so that the pump means and driving means are separable, and the driving means may be used with other pump means.

Abstract: A fuel filter unit having a fuel inlet chamber is threadedly mounted on a fuel pump for easy detachment therefrom. A tubular holder is fixed to the fuel pump for receiving fuel flowing out of the fuel filter unit when the latter is replaced. The fuel filter unit has a drain groove for collecting foreign matter trapped in fuel, so that any collected foreign matter will be discarded along with the fuel filter unit at the time of replacing the same. The fuel pump and the fuel filter unit are in fluid communication through an arrangement which includes a connector disposed in the fuel pump, and a fuel inlet pipe is connected to the connector through a side wall of the fuel pump. Therefore, it is not necessary to detach the fuel inlet pipe when the fuel filter unit is replaced.

Abstract: The pump has a pumping chamber with a deflectable diaphragm member and fluid inlet and outlet passages. A deflectable valve flap is disposed across the fluid inlet passage and another flexible valve flap is disposed across the fluid outlet passage. Movement of the flexible valve flaps is responsive to movement of the flexible diaphragm member, reciprocation of which establishes alternate sequential suction and discharge conditions. An air chamber provided in the pump receives outside air through an air vent opening and also communicates with the pump discharge passage through a bleed hole when the outlet passage is closed by the outlet valve flap. The outlet valve flap is also deflectable to a position where it closes the bleed hole. Under this arrangement, continuous siphoning of fluid through the pump after the pump has been shut down is obviated.

Abstract: A fluid pressure energized wear resistant pump valve is provided having a valve body and seal retainer formed of metal which secure a seal insert in assembly therewith. The seal insert incorporates an elastomeric sealing portion having a frusto-conical sealing surface for engagement with a valve seat of corresponding configuration. An anti-extrusion member is secured in assembly with the elastomeric seal portion and is composed of non-metal material of greater hardness than the hardness of the elastomeric material. The anti-extrusion member forms a frusto-conical sealing surface disposed in contiguous relation with the sealing surface of the elastomeric seal member. The anti-extrusion member further defines a tapered, yieldable peripheral sealing lip which yields responsive to pressure conditions to prevent pressure induced extrusion and damage to the elastomeric sealing member.

Abstract: A printer head, for an ink-on-demand type ink-jet printer, squirts ink droplets onto a printing medium. The printer head includes a nozzle for delivering the ink droplets and a passage for supplying ink from an ink tank. The ink is pressurized in accordance with an electric signal which commands the delivery of the ink droplets. Fluid control valves are deformed under the action of the ink pressure.

Abstract: This invention relates to a manual liquid dispensing device for spraying liquid by squeezing the trigger thereof. An adapter is inserted into a cylinder bore forming a pressurizing chamber. A piston is slidably mounted within the adapter. This adapter has an inlet communicating with the intake portion and an outlet communicating with an outlet passage to a nozzle hole formed at the bottom end thereof. A valve advantageously formed is attached to the end of the adapter to open only the inlet at pressure reducing time of the pressurizing chamber and to open only the outlet at pressurizing time. This valve is made of elastic material as a single unit.

Abstract: A low cost electromagnetic fluid pump having molded structural plastic housing components, a biased reciprocating hollow piston, and a pair of plastic flapper valves providing for a unidirectional fluid flow is disclosed. An integrated circuit timer periodically energizes a solenoid coil producing an oscillating magnetic field reciprocating the piston.

Abstract: A diaphragm pump having at least two working chambers communicating with inlet and outlet chambers via non-return valves, includes a reciprocal wobble plate affixed to a diaphragm in the working chambers. The wobble plate has a central guide shaft with a carrier at its free end, the carrier having resilient material, such as a rubber coating or rubber blocks, associated with it. A groove in a rotor connected to a drive shaft receives the carrier. The slope of the guide shaft with respect to the drive shaft is adjustable, and the resilient material holds the carrier in a preset eccentric position with respect to the drive shaft so that under overload conditions the carrier will press against the resilient material and reduce the eccentricity of the carrier with respect to the drive shaft. Once the overload conditions no longer exist, the guide shaft returns to its normal position and normal pumping continues.

Abstract: There are disclosed herein several embodiments of a pressure responsive discharge valve assembly particularly adapted for use in reciprocating type gas compressors. The valve assembly includes a discharge passage valve seat of frusto conical shape in which a generally complementary shaped light-weight valve member is disposed. The valve member is preferably formed from a polymeric material, but may also be formed of metal. The materials used and the relative geometry of the valve seat and member are such as to reduce clearance or reexpansion volume, provide quiet closure with good sealing, long life and high speed operation, and still have the required flow areas at low valve lifts, thereby providing improved flow characteristics and efficiency. The included angles of the valve and seat are slightly different to provide progressive closing and sealing without permanent deformation.

Abstract: Intravenous Fluid Pumping System having a controller and a pump controlled by the controller. The controller has a sealed chamber with a flexible membrane covering a portion thereof. An incompressible fluid is disposed in the chamber. A piston member is movable in the chamber causing extension and retraction of the membrane as the piston is moved in and out relative to the chamber. A motor is provided for reciprocating the piston. The pump has a pump body with a pumping chamber therein with one portion of the pump body being covered by a flexible membrane in contact with flexible membrane carried by the sealed chamber of the controller. The pump has an inlet adapter connected to the source of fluid. The pump also has an outlet adapter connected to the patient.

Abstract: An air pump comprising a piston located inside a piston housing having a crown and an open end. The piston is provided with a pressure generating member in the form of a resilient membrane-like annular disc which is held centrally on one end of the piston, which is fitted in the piston housing with the annular disc and the piston plate pointed towards the crown of the piston housing whereby the rim of the membrane-like annular disc bears against the inner wall of the piston housing and the piston housing is guided on the piston in a manner enabling it to be moved axially.

Abstract: A manually-operated pump dispenser for dispensing liquids from a container. The dispenser includes a one-piece housing coupled to the container, a dip tube extending from the housing into the container, a one-piece pump member which is slidably supported in the housing and which has a trigger extending therefrom and a nozzle member at the end, a pair of one-way valves supported by the housing and pump member, and a resilient, annular biasing member which engages the housing and pump member, has a stretchable portion providing a restoring force to the pump member and forms a part of at least one of the one-way valves in the dispenser. In a first embodiment, the biasing member forms a part of each of the one-way valves, and in a second embodiment, it forms a part of the inboard one-way valve. In this second embodiment, the outboard valve is formed by the nozzle member and the pump member.

Abstract: A head of an air pump for inflating pneumatic tires having a motorcycle valve comprises a pot-shaped housing defining a pressure space. The housing is arranged to be connected to an air pump defining a piston space so that the pressure space and the piston space are in communication with one another. A projection is formed integral with the pot-shaped housing and defines a cavity appliable upon a motorcycle valve including a valve body and a spring-biased check valve. A partition is provided between the cavity and the pressure space, the cavity of the projection communicating by at least one air duct passing through the partition with the pressure space. A check valve is provided in the cavity of the projection and is defined by a seal arranged around a lifting pin projecting from the partition into the cavity and leaving free between itself and the lifting pin a connecting duct.

Abstract: In a submersible pump of the type comprising a liquid inlet, a liquid outlet and an interconnecting valve chamber in which a valve member reciprocates to force liquid from the inlet to the outlet of the pump there is provided an improved valve member which uses a valve having an elongated body formed from a generally conical coil spring with abutting convolutions. The convolutions are opened when the valve member moves away from the pumping direction and closed when the valve member moves in the pumping direction.

Abstract: A carburetor is provided with a primer for aiding in starting an engine, the primer including a priming bulb for forcing air into the air space in the float bowl to cause the air pressure in the air space to be greater than atmospheric pressure and to cause liquid fuel to be forced through the fuel nozzle and into said fuel-air mixture passage of the carburetor. The priming bulb includes a flexible wall having a groove and a vent opening is located in the base of the groove and is positioned so as to close as the priming bulb is compressed and as air is forced into the air space of the float bowl. The carburetor also includes a narrow passage permitting the venting of a portion of the air forced into the air space of the fuel bowl by the priming bulb to thereby control the amount of liquid fuel injected into the carburetor venturi.

Abstract: There is disclosed an improved compressor cylinder head fabricated out of two separate parts to reduce cost and facilitate assembly, and an improved compressor valve plate for use with said cylinder head which utilizes multiple parts to provide concentric suction and discharge passages. A novel method of fabricating the valve plate is also disclosed.

Abstract: A disposable intravenous pump chamber cassette for an intravenous administration set which is specifically fabricated for use with the administration of blood. The pump chamber is specifically constructed to be utilized in conjunction with an intravenous pump having a driver to activate a diaphragm member and includes an improved outlet valve member having an outwardly extending lateral wall surface to direct the blood away from the biasing mechanism for the outlet valve member to thereby substantially reduce hemolysis.

Abstract: A fluid pump has an inlet, an outlet, a pumping chamber, pumping means, and inlet and outlet check valves. In one embodiment each check valve is formed by a flexible member positioned between a pair of relatively rigid members, the latter each having an opening bounded by a surface portion thereof with such surface portions cooperating with the flexible member to provide a fluid-tight seal therewith. The flexible member includes a movable means which moves upon flexure of such member in response to a pressure differential across the same and being operative when moved substantially to the respective extreme positions to block fluid flow between respective passages or to pass fluid flow between such passages. Moreover, a contact carrier is provided for repeatably intermittently closing contacts and opening the same. Such carrier is formed by a curved arm having a tendency to assume a natural condition, e.g.

Abstract: Well fluid pumping apparatus comprises:(a) body structure defining an upright plunger bore,(b) a plunger reciprocable in that bore,(c) the body structure also defining a chamber sidewardly offset from an axis defined by the plunger bore and communicating with the bore, and(d) valving carried by the body structure to pass intake fluid via the chamber into the plunger bore in response to stroking of the plunger in one direction in the bore, and to pass discharge fluid from the plunger bore into and from the chamber in response to stroking of the plunger in the opposite direction in the bore.

Abstract: There are disclosed herein several embodiments of a pressure responsive discharge valve assembly particularly adapted for use in reciprocating type gas compressors. The valve assembly includes a discharge passage valve seat of frusto conical shape in which a generally complementary shaped light-weight valve member is disposed. The valve member is preferably formed from a polymeric material, but may also be formed of metal. The materials used and the relative geometry of the valve seat and member are such as to reduce clearance or reexpansion volume, provide quiet closure with good sealing, long life and high speed operation, and still have the required flow areas at low valve lifts, thereby providing improved flow characteristics and efficiency. The included angles of the valve and seat are slightly different to provide progressive closing and sealing without permanent deformation.

Abstract: A dispensing device for discharging a liquid or pasty product from a container comprises a valve housing, provided with a vertical through passage for said product, including an upper inlet section for connecting the valve housing to an outlet of a container, a lower outlet section, and an intermediate valve chamber, defined between two resilient disk-like valve members which are spaced apart in the longitudinal direction of said passage and provided with thickened hub portions by which they are mounted on a supporting pin, located centrally within the valve chamber. In order to facilitate a simplified and less expensive manufacture and assembly of the device, the supporting pin is formed integrally with the valve housing which, as a whole, is formed in one single piece. The supporting pin projects upwardly into the valve chamber from a partial bottom wall of the valve housing. Near its lower end, supporting pin has a shoulder on which the hub portion of the lower valve member rests.

Abstract: A metering fluid pump including a cylinder and a pumping piston movable therein, the cylinder being configured to define a liquid inlet chamber on one side of the piston and a liquid outlet chamber on the opposite side of the piston. A suction valve for the inlet chamber and a pressure valve for the outlet chamber open simultaneously when the piston is moving in a first direction to simultaneously pump liquid out of the outlet chamber and draw liquid into the inlet chamber. Both valves close when the piston is moved in a second reversed direction to transfer the liquid through a constricted conduit from the inlet chamber into the outlet chamber. In a second aspect of the invention an accumulator may be provided which receives liquid under pressure from the inlet chamber and which transfers the liquid into the outlet chamber when the piston is moved in the second direction and is at the end of its transfer stroke.

Abstract: An annular elastic valve element is deformed under fluid pressure to control flow of fluid from a piston chamber to a pressure chamber of a piston pump by separation from the peripheral wall surface of a valve seat at a location through which a passage bore extends. The valve seat overlies the outer end of the piston and its peripheral wall has reduced diameter portions spaced from the bore to accommodate elastic deformation of the valve element.

Abstract: A pump for pumping an incompressible liquid comprising a housing having an inlet and an outlet, a pumping chamber in said housing, and a positive displacement pumping member mounted for movement in the pumping chamber. The housing has an inlet passage which leads from the inlet to the pumping chamber and an outlet passage leading from the pumping chamber to the outlet. Inlet and outlet check valves are provided in the inlet and outlet passages, respectively. A resiliently expandable chamber opens into the inlet passage upstream of the inlet check valve to receive the liquid and to be resiliently expanded by it.

Abstract: A container with an air tight lip incorporating a check valve for only evacuating air from the container by a piston suction pump sealed against the lip and around the check valve; the pump being arranged to receive manual pressure to produce the suction stroke and to simultaneously enhance the seal between the lip and the pump.

Abstract: The disclosure relates to a so-called pressure accumulation type atomizing pump provided with no gravity-actuated check valve and having an upper hollow piston and a lower pistion adapted to be simultaneously moved downward along the inner surface of a valve cylinder, upon a depression of an atomizing push button, the upper and lower piston being adapted to pressurize the liquid accommodated by a housing chamber defined within the valve cylinder between the pistons. The increased pressure of the liquid acts to depress the lower piston to open a check valve leading to a nozzle, so that the pressurized liquid is atomized finely from the nozzle. The lower piston is so arranged as to effectively cooperate with the upper piston in sucking the liquid up during the sucking stroke of the pump and to additionally increase the sucking capacity of the pump.

Abstract: A piston pump for mixing air into a liquid confectionary mixture uses resilient, duck-bill shaped valves in special valve bodies to provide efficient operation, easy assembly and disassembly, and easy cleaning. In one embodiment, a duck-bill valve in a central outlet passageway of a valve body functions as an outlet check valve and has an integral resilient disk portion that fits over a face of the valve body to function as a check valve for a plurality of spaced inlet passageways. In another embodiment, a duck-bill valve within an end of a cylinder of a pump is placed over a central inlet passageway, and a spool with circumferentially spaced holes is positioned about the duck-bill valve to aid in mixing confectionary mixture and air. A separate duck-bill valve as a check valve is positioned in an outlet passageway. By using only duck-bill valves in this embodiment, fruit pulp and seeds in confectionary mixtures can be readily pumped and mixed simultaneously without plugging the valves.

Abstract: A multiple valve assembly for use in the medical field includes a pair of flexible valve discs which are essentially co-planar with each other. A pair of tube connectors are oriented to be at an essentially right angle with respect to each other, and fluid communication between the interior of a hollow body and the tube connectors is controlled by the valve discs. An aspiration procedure has one valve disc in an open position and the other valve disc in an occluding position, and an injection procedure reverses the positions of the valve discs.

Abstract: A reciprocating adjustable stroke positive displacement fluid pump is provided with an expandable chamber driven in the displacement or feed direction by an eccentric drive acting through a driven member. The eccentric drive moves the expandable chamber to its limit of excursion in the displacement or feed direction. Adjustment means cooperating with stop means limits the excursion of the driven member and the expansion of the expandable chamber in the suction or intake direction so that the amount of fluid pumped is continuously adjustable from no volume to the capacity of the expandable chamber by positioning the stop means. The pump is further provided with means for driving a plurality of individually adjustable pumps from the same drive motor and with means for equalizing the load on the pump motor.

Abstract: In the illustrative embodiments of the invention disclosed, a non-aerosol pump includes a housing, a barrel within the housing forming a valve chamber, a pumping chamber within the barrel, a valve gland within the valve chamber for controlling intake and discharge flow to and from the pumping chamber, and a hand or finger-operated plunger for operating the pump. The valve gland has a circular seal lip on its axially outer surface for establishing a circular seal around the opening from the valve chamber to the pumping chamber. As pressure within the pumping chamber exceeds and falls below predetermined limits, the valve gland snaps open and closed, respectively, to provide a sharp on-off spray discharge. The check valve for controlling flow from the container to the pumping chamber may be formed integrally with the valve gland and of the same material or, alternatively, may comprise a ball check valve located within the gland.

Abstract: A sliding valve pump for oil wells which includes a working barrel having a plurality of apertures located in spaced relationship in the wall thereof and a pair of travelling valves fitted within the working barrel and carried by a plunger rod, the valves also having a plurality of apertures or ports for periodic registration with the ports in the working barrel wall to facilitate pumping of fluid from an oil reservoir or pool to the surface. The pump is designed to pull the oil-gas mixture from the reservoir pool into the lower section of the working barrel on the downward stroke, and to subsequently pump the collected oil through the barrel and tubing upwardly toward the surface on the upward stroke.

Abstract: A dispensing pump is provided with a non-throttling peripheral valve having a circular sealing edge with a diameter of greater than 3/4 inch and a thickness of less than 0.020 inch, and the valve is made of low density plastic material. The result is a pump which will operate at a very low, predetermined actuating pressure. A vent is included in the pump for venting a container to the atmosphere when air pressure in the container becomes reduced.

Abstract: Unique constructional improvements in constructions involved in pumping. The invention is particularly adapted in deep well pumps which may be water or oil pumps or otherwise. The invention greatly reduces the mass of moving parts thereby proportionately reducing the energy required for pumping operations. Dual pistons are utilized which reciprocate oppositely, being connected by a cable passing over a pulley. Heavy sucker rods and pistons are eliminated. The pistons are light-weight with light-weight bellows-type seals. The pistons are activated by way of cables rather than sucker rods. Further gains are realized by minimizing the size of the piping utilized. This end is realized by way of an offset staggered relationship of the operating pistons in a smaller pipe or by way of plural pistons arranged in vertical array or assembly.

Abstract: A dispensing pump of the pressure build-up variety includes a cylinder defining a variable volume pump chamber, and a main piston reciprocable therein, the piston having a valve seat thereon communicating with a discharge passage leading to a discharge nozzle. A valve member having a smaller diameter piston thereon is moved during pressure build-up away from the seat for opening the discharge passage. The smaller diameter piston has a flexible peripheral wall which is deformed inwardly at the commencement of the piston downstroke for closing a flow passage in the smaller diameter piston and thereby interrupting communication between the inlet and the pump chamber, such flow passage being open upon outward movement of such peripheral wall at the end of the piston upstroke. At the top of the cylinder along which the smaller diameter piston moves is a relieved section effecting the opening of the flow passage in an inoperative condition of the pump.

Abstract: A downhole pump has spaced upper and lower pistons connected together by a common rod so that the pistons reciprocate within a cylinder. The cylinder is separated into an upper and lower engine chamber by a frame supported from the cylinder wall and arranged laterally with respect to the longitudinal axial centerline of the connecting rod. A bushing is positioned centrally of the frame and sealingly engages a reciprocating marginal length of the connecting rod. An exhaust port is formed through the frame in spaced relationship to the bushing. A resilient exhaust valve element surrounds the bushing and includes a lower, circumferentially extending edge affixed to the frame outwardly of the exhaust port and further includes an upper seal end which sealingly engages a marginal external surface of the bushing.

Abstract: The inlet and discharge valves of a pump are each comprised of a circular valve plate centered in a circular cutout in a flat valve sheet. Diametrically opposed webs join the valve plate to the main body of the valve sheet and perforations in the webs provide both, spring action and allow for air passage.

Abstract: A valve element for a small sized air pump. The valve element has legs, each of which are tightly secured within holes of valve-beds of a valve casing. A longitudinal hole is formed within each of the legs. The hole of the leg is opened at one end and closed at the other such that the hole terminates at a level horizontal to the lower surface of the valve-beds when the valve element is assembled.

Abstract: A multi-stage pumping assembly comprising a plurality of pumping units arranged end to end in an elongate cylindrical housing. Each pumping unit comprises a solenoid which when energized causes a pumping piston to retract downwardly on its intake stroke, and when de-energized permits a tension loaded rubber sleeve element to pull the piston upwardly on its discharge stroke. Each of the solenoids is energized in sequence so that the pumping pistons move through their pumping cycles in a sequential pattern. In pumping against lower pressures, each piston is able to move through a longer path of travel on its discharge stroke to effect a higher volumetric flow of liquid. When working against higher head pressures, the pressure exerted by the several pumping pistons, working cumulatively effects a lower volumetric flow of fluid at a higher pressure.

Abstract: A pump comprising a supporting structure including a bearing support, a wobble plate, a bearing between the bearing support and the wobble plate for permitting the wobble plate to nutate and for transmitting radial loads from the wobble plate to the bearing support, a cam rotatably mounted on the supporting structure for causing the wobble plate to nutate, and a mechanism for drivingly coupling the cam to a shaft of a motor. Radial loads are transmitted by the bearing to the supporting structure rather than to the cam. The wobble plate is coupled to a suitable output device such as the diaphragm of a diaphragm pump.

Abstract: An improved valve mechanism for a small sized air pump, having valve elements each of which is secured in a housing of a valve casing. The valve element has a semi-circular portion and a tongue. The semi-circular portion is trapezoidal and snuggly and firmly positioned within the housing.

Abstract: A pump for use in a doll having a transparent front torso through which is viewed simulated internal organs, the pump being connected to coiled transparent tubing for passage therethrough of a liquid-air mixture. The pump has a main body portion with a generally cylindrical recess having a circular surface with a coaxial annular groove in the surface and an arcuate groove disposed radially outwardly from the annular groove. An inlet aperture is disposed radially outwardly from the annular groove and is in fluid communication therewith while an outlet aperture is in fluid communication with the arcuate groove with the two grooves being interconnected by a groove segment. A one-piece diaphragm is provided with a flange adapted to sealingly engage the surface, the diaphragm having a deformable dome-shaped portion extending outwardly from the surfce to form a chamber, the diaphragm having a skirt portion fitting within the annular groove with the skirt having a cutaway portion in proximity to the groove segment.

Abstract: A flexible diaphragm having an arcuate ridge defines the pumping chamber of a fluid pump and is reciprocated by connection to the output shaft of an electric motor. The rigid plate portion of a connector is joined to the central portion of the diaphragm while the remainder thereof extends in an opposite direction where it is linked with an eccentric coupling carried by the output shaft of the motor. Although the diaphragm is driven in a rocking, reciprocating movement, the housing is formed with surface support portions which have radii of curvature such as to support the diaphragm during its distended periods, thereby assuring a long lifetime of diaphragm operation. The overall arrangement results in improved efficiency in pumping gases as well as liquids.

Abstract: A fluid transfer device is provided for administration of medicament to a patient. The device includes a plastic housing having a first inlet, a second inlet and an outlet, and an umbrella check valve coupling the inlets and outlets. The umbrella check valve is positioned so as to permit flow from the first inlet to the second inlet and from the second inlet to the outlet, but to block flow from the second inlet to the first inlet and from the outlet to both the first inlet and the second inlet.

Abstract: An atomizing pump assembly for use with a variety of types of containers is disclosed in which a housing is formed with both an outlet port and an internal fluid chamber that communicates via a passageway with the outlet port. Tubular means provides communication between the fluid chamber in the housing and a reservoir of the material that is to be dispensed by the pump. A flexible frustroconical skirt or diaphragm having a valved opening therethrough is operatively located intermediate the tubular means and both the fluid chamber and the outlet port, with an integral upper portion of the diaphragm initially obstructing the outlet port. When an actuating cap is depressed, material within the fluid chamber is compressed until a minimum predetermined chamber pressure is achieved, whereby under pressure the skirt or diaphragm is flexed from its normal position to a discharge position.

Abstract: A non-pulsating, non-throttling, vented pumping system is disclosed for continuously dispensing product from a container in a relatively non-pulsating stream or spray. The pumping system includes a pump for withdrawing product from a container and for pressurizing the product, a storage compartment for storing the product under pressure, an accumulator piston in the storage compartment acting under bias to maintain the pressure on the product, an outlet passage opened and closed by the accumulator piston, and a restricted orifice at the outlet passage through which the product is dispensed as a stream or spray. The restricted orifice allows only a portion of the product pressurized by the pump to escape during the pressure stroke of the pump, and the remainder of the product is stored in the product storage compartment to be released for maintaining the spray or stream when the pressurizing pump is acting on its intake stroke.

Abstract: A fluid dispenser pump having a piston extending from one end of a cylinder with resilient means urging the piston from the cylinder to its extended position for manual movement into the cylinder to its retracted position, said piston and cylinder being elastomeric plastic members, with complementary cylindrical walls forming a sequence of chambers. An inlet chamber communicates with a fluid supply. An auxiliary pressure chamber is normally sealed from the inlet chamber, but it communicates with the inlet chamber whenever the piston is at its fully extended position. An operating chamber communicates with the auxiliary pressure chamber and a first check valve means between the chamber permits flow from the auxiliary pressure chamber to the working chamber, but prevents a reversal of such flow. A discharge chamber communicates with the working chamber and a second check valve means between the chambers permits flow from the working chamber to the discharge chamber but prevents a reversal of such flow.

Abstract: A finger-operated spray pump assembly including a compression chamber, a generally cylindrical valve slidably fitted inside the compression chamber, a piston slidably fitted inside the valve, and a spring fitted inside of the valve for urging the piston away from the bottom end of the valve.

Abstract: This invention relates to liquid metering pumps and according to the invention such a pump comprises a cylinder permanently connected to an inlet passage for the liquid and in which said cylinder a plunger piston is arranged to slide said piston co-operating with a sealing gland on the inlet side. The piston is urged by an elastic member into contact with a reciprocable actuating rod which co-operates with a sealing gland on the outlet side. The two sealing glands are separated by a spacer to form an annular chamber around the plunger piston and the actuating rod.

Abstract: In a diaphragm fluid pump, a pump housing comprises a cylinder provided therein coaxially with an operating rod of a diaphragm piston assembly hermetically assembled within the housing, and a driving mechanism for the operating rod includes a piston element mounted on the free end of the operating rod and slidably engaged within the cylinder to regulate the axial movement of the operating rod, whereby the diaphragm piston assembly is reciprocated without twisting thereof.

Abstract: To suck and discharge the air into and from a pressure reducing chamber of a vacuum pump, a check valve comprises a valve body made of plastic material in a mushroom configuration, and a plate member which includes a flat valve seat surface to be engaged with the annular rim of the cap portion of the valve body, an assembling hole to be coupled with the neck portion of the valve body, and a plurality of openings positioned symmetrically on a circle concentric with the assembling hole to normally be closed by the cap portion of the valve body. The neck portion of the valve body is assembled with the assembling hole under axially and radially compressed condition to air-tightly engage the annular rim of the cap portion of the valve body on the valve seat surface.