Abstract: In a membrane pump for very high pressure, an axially moveable control member is provided in a body which borders a fluid handling chamber to form a narrow annular clearance around the control member and to form at the axial movement of the control member a cross-sectional area for big flow-through fluid quantities and temporarily a very narrow clearance for the prevention of deflection of portions of the membrane over the flow-through fluid passage.

Abstract: A micropump comprises a housing for defining a pump chamber, an inlet valve disposed in an inlet flow passage, a outlet valve disposed in a outlet flow passage, and an actuator for changing a volume of the pump chamber. The actuator is formed of a thermo-responsive polymer gel material. Fluid is supplied and fed by heating and cooling the actuator.A micropump comprises a pump body member for defining a tank chamber holding liquid, a liquid inlet portion, a liquid outlet portion for discharging the liquid medium in the tank chamber, a liquid outlet portion for discharging the liquid medium in the tank chamber, and an actuator, for reducing a volume of the tank chamber. The actuator is formed of a liquid-absorptive polymer gel.

Abstract: A pump for dispensing accurately measured amounts of fluid has a one way check valve in the flow path on the upstream side of a pump chamber and a one way check valve in the flow path at the downstream side of the pump chamber which is of variable internal volume. A flow passage provides fluid communication from the upstream check valve to the pump chamber and enters the pump chamber by a centrally located opening that is surrounded by a valve seat. One wall of the pump chamber is a flexible and elastic diaphragm that is attached to the plunger portion of a solenoid actuator. The plunger and diaphragm are biased by a spring acting upon the plunger such that, in the absence of excitation of the solenoid coil, the diaphragm is biased against a valve seat, preventing flow through the pump.

Abstract: A diaphragm pump comprising a pumping chamber (10) is operated by a continuous flow of pressure gas to a driving chamber (12) separated from the pumping chamber by a flexible diaphragm (8 or 52). Deflection of the diaphragm by the gas pressure drives liquid out of the pumping chamber. The driving chamber has a normally closed outlet valve (30 or 54) connected to the diaphragm through a flexible or lost-motion connection (34, 36 or 56) so that the valve is opened after a certain deflection of the diaphragm. The driving chamber pressure is thereby released and allows the diaphragm to return, drawing further liquid into the pumping chamber. The return movement of the diaphragm also allows the valve to reclose and the cycle is repeated while the supply of pressure gas to the driving chamber is maintained.

Abstract: A multi-diaphragm metering pump having first and second diaphragms mounted in a body in substantially parallel relationship, wherein an open fluid communication path is provided within the body between adjacent sides of the diaphragms and wherein each diaphragm forms a sealed wall within the body. A diaphragm stem connects the diaphragms, such that movement of the first diaphragm will cause movement of the second diaphragm substantially in unison. A source of pressurized fluid is intermittently injected into and exhausted from a remote side of the first diaphragm, thereby causing cyclical movement of the two diaphragms, whereby a transient fluid may be pumped on the remote side of the second diaphragm by the cyclical movement. In a preferred embodiment, a sealed enclosure is formed between the two diaphragms.

Abstract: A primary fluid actuated, secondary fluid propelling system, suitable for use, for example, as an implantable, artificial heart device, comprises a unidirectional pump for pumping electrorheological fluid, two return loops connected to the pump, and for each return loop, two electrorheological valves therein in series flow, and a primary fluid actuated, secondary fluid propelling device connected to that loop at a position between the two electrorheologocal valves therein. The primary fluid actuated, secondary fluid propelling devices may comprise a casing having the interior thereof divided by a pressure transmitting flexible diaphragm into a first cavity for receiving electrorheological fluid from that return loop, and a second cavity for propelling the secondary fluid. The electrorheological valves are actuated to pressurize one first cavity while emptying the other and vice versa.

Abstract: A diaphragm pump for gas-containing fluids, in which the chamber for the fluid to be pumped is of frusto-conical shape corresponding to the elastic diaphragm, the minor-diameter edge of which is connected to a rigid central disc provided at its periphery with a frusto-conical support surface for the underlying diaphragm. A protection system is provided for the elastic diaphragm.

Abstract: A double membrane pump comprising a central housing (1), two coaxial product chambers (6) in the central housing, suction and pressure valves for each product chamber, two membranes (7) sealing off the product chambers externally from coaxial pressure fluid chambers (8), piston rods (13) guided in external seals, a U-shaped external crosspiece (17) connecting the piston rods of the membranes and a control block for reciprocally pressurising the pressure fluid chambers with pumping medium and comprising a slide valve (20) actuated by the movement of the membranes. The pump provides a very short path for the pumping flow, with only two changes in direction, and only static seals. It can be made wholly of plastics materials and is particularly suitable for high-purity products in the semiconductor industry, in biotechnology and in the pharmaceutical, cosmetic and foodstuffs industries.

Abstract: The invention is directed to a membrane fuel pump for a membrane carburetor of an internal combustion engine. The carburetor has a pressure controller and the engine has a crankcase wherein pressure fluctuates during the operation thereof. The membrane fuel pump includes a pump membrane mounted in a housing which partitions a space of the housing into a pump chamber for receiving fuel from a fuel supply connection and a drive chamber. The drive chamber is charged with the pressure of the crankcase. A pressure connection connects the pump chamber to the pressure controller of the membrane carburetor. A bypass channel connects the pressure connection to the fuel supply connection and a valve is interposed between the pressure connection and the bypass channel.

Abstract: A method and apparatus for controlling the discharge time of a fluid activated diaphragm pump. The control system regulates the discharge time, by measuring the discharge time and comparing the measured time with a predetermined desired discharge time. The control system includes, inter alia, a programmable logic controller, an upper and lower proximity switch, a target, a rod to hold the target, a pilot controlled pressure regulator, a set of digitally controlled solenoids which control a pilot valve, a solenoid, and a pressure switch. The rod is secured to the diaphragm of the diaphragm pump, and the proximity switches respond to the movement of the rod to detect the movement, or stroke, of the diaphragm. The pressure supplied to the diaphragm pump is automatically, and continuously, adjusted to maintain a desired discharge time.

Abstract: A liquid chromatographic method and apparatus is disclosed which employs an improved pump not requiring driven pistons or sliding seals. The pump comprises at least one length of tubing forming a chamber disposed between first and second check valves, controllable heating means to periodically heat liquid in said chamber effective to pump relatively low volumes of liquid from the chamber at relatively high pressures, means for measuring the pressure developed by the pump, and control means to increase and decrease the amount of heat imparted to the liquid to maintain the pump operation at a controlled pressure setpoint.

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

Abstract: In a hydraulically controlled diaphragm pump for high pressures, the diaphragm situated between the hydraulic control chamber and the working chamber is composite and comprises two thin metal diaphragms having between them an intermediate diaphragm that is thick, is made of synthetic material, has high crushing strength, and is in the form of an elastically deformable vault whose concave side faces towards the working chamber.

Abstract: An improved condiment dispensing system for delivering a measured quantity of condiment at a constant flow rate. The device comprises a pump which is fluidly connected to a condiment source and a dispensing apparatus. The dispensing apparatus includes a valve assembly which is connected to both a pressurized fluid source and to the pump whereby actuation of a valve assembly contained on the surface of the dispensing apparatus causes a measured quantity of condiment to be dispensed from an outlet nozzle contained thereon.

Abstract: A double diaphragm pump having an air chamber housing centrally located between two water chamber housings. The air chamber housing includes a center section and two outwardly facing concave discs. Each water chamber housing includes a water chamber shell mating with one of the discs with a flexible diaphragm therebetween. Also included integrally formed with the water chamber housing are check valve chambers and inlet and outlet passages. The passages of one water chamber mutually converge with the passages of the other water chamber to receive T-couplings for providing both inlet to and outlet from the pump. O-rings are held in interference fit between the T-couplings and the mutually converging portions of the inlet and outlet passages. Shoulders on the T-couplings and portions keep the O-rings in place. Spacing inserts are employed in each passage to locate either a valve seat or a ball check valve and to close off access openings through the wall of the chamber.

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

Abstract: In a high volumetric efficiency compression machine that can be used as a compressor, pump, or actuator, a compression chamber is formed by a movable body and the inner wall of a casing. A discharge valve is formed in the casing, and communicates with the compression chamber. Two intake valves are formed in the casing, communicate with the compression chamber and are arranged symmetrically with respect to the axial direction of the discharge valve. A rod transmits reciprocation to the movable body.

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

Abstract: A double diaphragm pump having an air chamber housing centrally located between two water chamber housings. The air chamber housing includes a center section and two outwardly facing concave discs. Each water chamber housing inlcudes a water chamber shell mating with one of the discs with a flexible diaphragm therebetween. Also included integrally formed with the water chamber housing are check valve chambers and inlet and outlet passages. The passages of one water chamber mutually converge with the passages of the other water chamber to receive T-couplings for providing both inlet to and outlet from the pump. O-rings are held in interference fit between the T-couplings and the mutually converging portions of the inlet and outlet passages. Shoulders on the T-couplings and portions keep the O-rings in place. Spacing inserts are employed in each passage to locate either a valve seat or a ball check valve and to close off access openings through the wall of the chamber.

Abstract: A fluid dispensing system is provided which has first diaphragm pump means, a filter connected to receive the discharge of the first pump, and second diaphragm pump means connected to the receive the discharge of said filter. Hydraulic fluids pumped by cylinder/piston/stepper assemblies independently actuate each of the diaphragm pumps, providing accurate, controllable and repeatable dispense of the subject fluid. In addition, pressure sensing means are provided to indicate the pressure of the actuating hydraulic fluids, and computer controller means may be utilized to monitor, adjust and control the rates and intervals of filtering and dispense of the system in response to said pressure sensing means or otherwise.

Abstract: An improved condiment dispensing system for delivering a measured quantity of condiment at a constant flow rate. The device comprises a pump which is fluidly connected to a condiment source and a dispensing apparatus. The dispensing apparatus includes a valve assembly which is connected to both a pressurized fluid source and to the pump whereby actuation of a valve assembly contained on the surface of the dispensing apparatus causes a measured quantity of condiment to be dispensed from an outlet nozzle contained thereon.

Abstract: The present invention relates to a spin coating apparatus for feeding a clean liquid at a fixed rate. In any of the feeding apparatus in the prior art, no constituent other than a filter has the function of eliminating foreign matter, and the operation of feeding a liquid under precise control is not attained. This results in the problem of the mixing of the foreign matter (and air bubbles) in the feed liquid, and the problem of nonuniformity in a feed speed as well as a feed amount. As expedients for solving these problems, the present invention provides the functions of automatically sensing and excluding factors for the appearances of the foreign matters, and devices for automatically and precisely controlling feed control elements such as a pump, thereby feeding the clean liquid in a constant amount and at a constant speed.

Abstract: The piston membrane pump has a feed chamber for the fluid to be pumped and a piston working chamber, a membrane hermetically separating the feed chamber and the piston working chamber and a piston oscillating back and forth in the piston working chamber. The piston working chamber is completely filled with a hydraulic medium from a supply container in operation so that the membrane oscillates with the piston. A refill valve which connects the piston working chamber with the supply container cooperates with a spring-loaded sliding control element and a moving force-transmitting element displaceable against it so as to open the valve. So that the pump can operate at higher pressures and temperatures a metal membrane is used, the force-transmitting element is a resilient platelike piece acting against the spring-loaded sliding control element and the membrane has no contact surfaces in the feed chamber on its feed chamber side.

Abstract: This invention relates to an improved gas-driven pump for pumping products, such as beverage syrups. A piston is mounted to a piston shaft for reciprocal movement within a housing. Cavities corresponding to the piston are alternately vented and pressurized to intake the product into a first chamber and to drive the piston to pump the product. A valve stem is included within the housing and is adapted such that the piston performing intake and exhaust strokes moves the valve stem between intake and exhaust positions. A valve body is disposed about the valve stem which is also movable between two positions for alternately venting and pressurizing a second chamber. The valve stem which is operable to move the valve body is biased toward the intake or exhaust position by an overcenter spring disposed within the second chamber.

Abstract: In a diaphragm pump with mechanically driven diaphragm and a device for diaphragm rutpure signaling, wherein the diaphragm 2 is clamped at the edge between a pump body 3 and pump cover 4 and is centrally firmly connected with a support plate 5 serving to drive the diaphragm, the design is such that the diaphragm is formed as a multi-layer sandwich diaphragm 2, whose individual layers or diaphragm plies are clamped jointly in the edge region between pump body 3 and pump cover 4. The sandwich diaphragm 2 consists of a working diaphragm 18 with at least one diaphragm ply and a protective diaphragm 20 also with at least one diaphragm ply. The latter is formed so that, with the working diaphragm 18 intact, it is clearly stressed by the delivery pressure less than the working diaphragm 18. Lastly the device for diaphragm rupture signaling has at least one channel 22, 25 disposed between the diaphragms 18, 20 and brought to the outside, for signaling a rupture of the working diaphragm 18.

Abstract: A fluid pumping apparatus and system including a double acting diaphragm pumping device in which each pumping component has a pair of spaced apart diaphragms defining a containment chamber and all exposed surfaces in the pumping chamber and the containment chamber are made of an inert plastic material, a fluid sensor extending into each containment chamber for sensing the presence of unwanted fluids therein, and a pump control system for activating the pumping apparatus and responding to an output signal generated by either sensor to deactivate the pumping apparatus in the event of leakage of fluid into either containment chamber.

Abstract: The pump has several cylinders which are arranged in a row narrowly adjacent to one another and which accommodate the stroke working spaces of plungers or pistons. The stroke work of the pistons is hydraulically transmitted to diaphragms which close off pump working spaces inside of diaphragm working spaces in the direction of the cylinders. Because of the arrangement of the diaphragm working spaces or of the pump working spaces on different sides of the cylinder block, diaphragms or diaphragm working spaces may be arranged which have cross-sections that are large in comparison to the distance of the cylinders from one another.

Abstract: A blood pump is disclosed that is useful as ventricle assist or replacement device comprising a housing having a blood chamber and inlet and outlet ports for the ingress and egress of blood to and from the chamber. A deflectable diaphragm comprises a wall of the blood chamber which upon deflection collapses the blood chamber to urge blood from the chamber out the outlet port. A pusher plate is disposed in association with the diaphragm. The pusher plate includes a collapsible guide mechanism which guides the plate from a first fill position to a second eject position. The guide mechanism can comprise a telescopic guide or straight-line linkage which is collapsible to a first fill position to occupy a substantially lesser space in the housing than when extended to second eject position. The guide mechanism avoids the necessity of a projection from the housing to accommodate a stroke of a guide mechanism. The guide mechanism can be independent of or combined with the drive means.

Abstract: A positive displacement pump comprises a mass such as a liquid filled pressure chamber or an annular ring which is rotated at high speed about a first axis so that centrifugal force acting on the liquid or ring creates zones of differential pressure within the interior of the pressure chamber or along the wall of the ring. At least one pumping unit having a pressure-responsive member is oscillated or rotated between the zones of differential pressure while the center of gravity of the pressure chamber or ring is maintained at a fixed distance from the first axis. In the course of moving into one zone having one pressure, the pressure-responsive member of the pumping unit is effective to intake a fluid such as air into the pumping unit. Air is discharged from the pumping unit by the pressure-responsive member in the course of moving from such one zone into another zone having a different pressure.

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

Abstract: An apparatus for controlling the hydraulic circuit of a piston diaphragm pump, having at least a pump diaphragm alternatingly subjected to the presure or the suction stroke of a piston operatingly connected to driving means, the apparatus comprising control means changing the amount of hydraulic medium displaced by the piston in dependence of a power demand or the like. A displacement sensor is associated with one side of the diaphragm facing the hydraulic medium, the sensor measuring the stroke travel of the diaphragm and generating a corresponding stroke travel signal which is transmitted to control means, the control means including storage means storing predetermined stroke values and/or stroke value ranges for predetermined hydraulic power values of the pump.

Abstract: Apparatus for driving a medical appliance has a single compressor for generating both the positive and negative pressures. The switching valves are connected to the outlet and inlet terminals of the compressor. The outlet and inlet terminals of the compressor are also connected to the positive pressure accumulator and the negative pressure accumulator, respectively. The apparatus has the pressure sensors to sense the pressures in the positive and negative pressure accumulators. When the pressure in the accumulator reaches a set pressure, at least one of the switching valves is closed. The apparatus further has the relief valves connected to the outlet and inlet terminals of the compressor. These relief valves open when the pressures of the compressor become excessive.

Abstract: In accordance with the present invention, a diaphragm pump having a housing, a first chamber within said housing, a second chamber within said housing and a pair of diaphragm elements mounted in said housing between said first chamber and said second chamber, is provided with a failure sensing system for the diaphragm. The failure sensing system including a failure sensing device which is between the two parts of the diaphragm and an indicator circuit which includes the conductive liquid which is being pumped and an alarm. The two parts of the diaphragm element are clamped together proximate their peripheral edge such that a circumferentila fluid tight compression seal region is provided. The sensing device includes an electrically conductive lead which extends from the exterior of the housing, through the circumferential fluid tight seal region into the region peripherally inward of the seal region.

Abstract: Pumps for nonlubricating fluid can use membranes for the separation of different fluids. Suitable membranes can be used for pressures up to several thousand atmospheres in the fluids. Such membranes are, however, subjected to difficult problems like stresses in the material of the membrane, compression of the material of the membrane and the like. These problems prevented long life of the membranes or it restricted the membranes to such short strokes that the deliveries of the pumps were small at a given size and weight. The present invention improves the life time and the delivery capacities of membranes by creating most suitable configurations of the membranes and of the adjacent parts. Pumps or compressors for relative big delivery quantities, and also for high pressures up to several thousand atmospheres in cases of pumps, are thereby obtained.

Abstract: The groove (13) for detecting the presence of a fluid between the membranes (1, 2) and indicating that one or other of them has broken, is profiled so as to be bullet-shaped, thereby preventing the membranes from being extruded into the groove under the effect of pumping pressure.

Abstract: A hydraulically activated diaphragm pump. A pressure source is coupled to a pump diaphragm during a pump discharge stroke. During this discharge stroke, an air activated return assist cylinder is vented to atmosphere. On the return stroke the pump housing above the diaphragm is vented and the air cylinder activated. A single 4-way solenoid actuated valve controlled by an adjustable timer accomplishes this cylic pumping action. The timer is adjustable to set the number of pump cycles per minute and also adjusts the discharge stroke period of each cycle. A pressure regulator adjusts the pressure of air routed through the solenoid actuated valve to provide relatively high pressure air to the diaphragm on the discharge and low pressure air to the air cylinder on the return stroke.

Abstract: Briefly, the present invention comprises a combined mechanical shifting mechanism and pneumatic pilot valve construction to contrl the cycling of a double diaphragm pump. The mechanical cycling or shifting mechanism is positioned between pressure chambers of the diaphragm pump in the pump housing and extends axially into one or the other pressure chamber. The shifting mechanism moves axially in response to engagement by one of the pump diaphragms. Upon engagement by a diaphragm, the mechanical shift opens fluid pressure passageways to a pneumatic pilot valve which controls fluid flow to the respective pressure chambers associated with the diaphragm pump. A positive pilot signal is thus supplied through the entire stroke or cycle of the diaphragm pump. The mechanical shifting mechanism is not connected directly to a diaphragm or to the connecting rod which connects the diaphragms.

Abstract: A pneumatically operated fuel injection pump has a work chamber which is partitioned by a membrane into a pulse chamber and a return chamber. The pulse chamber is charged with crankcase pressure from a two-stroke engine while a counterforce is built up in the return chamber which varies with rotational speed. A counterforce is developed by means of a precise pressure control in the return chamber which makes possible a highly precise injection adapted to rotational speed. For this purpose, the return chamber is connected with an adjusting volume via a throttled flow path. In addition, a leaf spring is mounted in the return chamber and is utilized as a return spring for the membrane.

Abstract: A coating material supply device capable of accurately supplying even a highly viscous coating material such as a two-component coating material by a constant amount to a coating machine with no trouble, as well as with no requirement of individually disposing flowmeters, e.g., for respective colors in the case of multicolor coating under color-change.

Abstract: A pneumatic pumping device incorporating a movable valve such as a bellows, are diaphragm, driven by air back pressure in a cylinder so that a liquid is drawn in and discharged by reciprocating movement of the movable valve, and in which surfaces contacting the liquid on the internal and external parts of the pumping device are formed of either a single substance or a compound of a fluororesin such as PTFE, PFA, CTFE in order to feed strong acid liquid or strong alkaline liquid without corrosion on components of the pumping device.

Abstract: An improved double acting diaphragm pump utilizes at least one supplemental diaphragm and associated pressure chamber arranged coaxially with the connecting shaft of the main diaphragms. The supplemental chambers are connected via parallel pressure lines or conduits to the pressure source for the main diaphragms and associated pressure chambers.

Abstract: Apparatus for controlling the flow of a foam uses a bellow enclosed in a housing. The bellows is filled with foam under pressure from a foam generator and expands a preselected amount at which point the flow of foam into the bellows is interrupted. Simultaneously with the interrupting of the flow of foam into the bellows, air under pressure is routed into the housing which causes the bellows to collapse forcing the foam out of the bellows. The apparatus is particularly useful in the froth flotation (benefication) of minerals.

Abstract: A single-acting, gas-operated, pump method and apparatus including a pump body having a main chamber divided by a reciprocating piston assembly into a gas driving chamber and a liquid pumping chamber, a spring for biasing the piston assembly into one of its two end positions, a reciprocating control valve controlling the flow of driving gas to and from the gas driving chamber, a snap-acting spring mechanically coupling the control valve to the reciprocating movement of the piston assembly, and a counteracting spring for biasing the control valve toward one of its two positions.

Abstract: A marine propulsion system (200) having an outboard two cycle internal combustion engine (212) has a modified oil-fuel mixer (2, 602) preventing excess oil in the mixture as fuel runs out. The modified mixer includes an auxiliary chamber (602) having a fuel inlet (604) receiving fuel from the working chamber (22) of the mixer below a given level, a vapor inlet (606) receiving fuel vapor or air from the working chamber above the given level, and a vapor outlet (608) exhausting the vapor. When the fuel tank (5) runs dry, air is drawn through a transfer passage (38) in the mixer to one side of the moveable diaphragm (24), and fuel pump (11) suction is applied to both sides of the diaphragm to halt movement thereof and stop further pumping of oil from the oil tank (7) to the engine. The invention also enchances accuracy of the oil-fuel mixture ration during normal operation.

Abstract: Liquid-transfer equipment and method for dispensing liquid reagents for chemical assays, which equipment and method provide time-controlled metering of the quantity of liquid dispensed even though the liquid supply reservoir is not pressurized.

Abstract: A pressure chamber of a diaphragm pump having an outer chamber improved so that it is free from stress concentration. The inner wall surface of the pressure chamber is recessed in a mero-spherical shape. In order to support this chamber wall from its rear side, an outer ring rib is provided along the outermost periphery of the outer surface of the chamber, and an inner ring rib is circumferentially disposed at the inner side of the outer ring rib. Further, radial ribs are provided so as to connect together the outer and inner ring ribs in the radial direction.

Abstract: The invention relates to a fuel injection arrangement wherein the pump piston of the fuel pump is driven by the pressure in the crankcase of the engine. The fuel injection arrangement includes an opening for tapping the crankcase pressure for actuating a diaphragm in the fuel pump. This opening is controlled by a moving part of the engine such as a crank web or the piston. The moving part closes the opening at least for a portion of the time during which injection occurs thereby delaying the onset of injection to permit a complete combustion during the previous combustion cycle.

Abstract: The invention is directed to a fuel injection arrangement for two-stroke engines for portable tools such as motor-driven saws. In known fuel-injecting arrangements, the injection pump is driven by the pressure of the crankcase. The crankcase pressure increases up to a maximum value which remains constant starting with a predetermined rotational speed up to and including the maximum rotational speed. When the peak pressure of the crankcase is constant, the stroke of the pump piston of the injection pump is also constant and so is the quantity of fuel which is pumped. However, at higher speeds where the speed is increasing because of throttling in the air intake channel, the air charge of the cylinder reduces and an overrich mixture is formed. The fuel injection arrangement of the invention provides for an automatic reduction in the quantity of fuel injected at high and at the highest speeds.

Abstract: A pneumatic drive circuit for a pneumatically-driven artificial ventricle having a gas chamber and a blood chamber separated by a flexible diaphragm. The drive circuit comprises a source of pressurized gas at a preselected pressure. Valves operatively associated with the gas chamber of the ventricle admit gas to the gas chamber during systole and exhaust gas from the gas chamber during diastole. The drive circuit includes pneumatic logic circuitry for actuating the valves. The logic circuitry includes circuitry for causing the valves to admit gas to the gas chamber during systole at a pressure which increases gradually from zero pressure to a pressure less than the preselected pressure, and then increases rapidly to the preselected pressure.

Abstract: A gas system using a liquid to provide an oil-free, virtually noiseless positive/negative pressure to a pressure vessel. A high-pressure gas-storage reservoir, a compression tank and a pump liquid supply reservoir are interconnected by a series of valves. To provide a high positive pressure to a gas, a low pressure gas is admitted to the compression tank and then liquid is pumped from the storage reservoir into the tank, which has a flexible membrane separating the gas and the liquid. The liquid compresses the gas which is then vented out of the compression tank to the gas storage reservoir and the pump liquid is drained back into the liquid supply reservoir. A low pressure may be applied to the compression tank by first filling the tank with liquid and closing all inlet valves. Then a drain valve is opened to the liquid supply reservoir causing evacuation of the tank.