Abstract: A dual-action pump includes a cylinder, a piston and a controller. The cylinder includes first and second inlet-outlet ports, each of the first and second inlet-outlet ports is configured to alternately intake a fluid to the cylinder and output the fluid from the cylinder. The piston is configured to be moved within the cylinder in a periodic cycle that alternately reverses a direction of movement of the piston, so as to pump the fluid through the first and second inlet-outlet ports. The controller is configured to control the movement of the piston within the cylinder, including setting to the piston: (a) a first speed, during a first predefined interval that precedes reversing the direction of movement, (b) a second speed, larger than the first speed, during a second predefined interval that follows reversing the direction, and (c) a baseline speed, smaller than the first speed, outside the first and second intervals.

Abstract: An actuating device mechanically controls a membrane pump device. The device includes a base body having a mounting face for a membrane pump device and through which a control fluid line passes that extends from a control fluid port to a control fluid opening that opens at the mounting face. A control fluid valve arranged in the control fluid line influences a cross-section of the control fluid line and has an adjustment device that has a fluid actuator arranged on the mounting face. A working fluid valve influences a cross-section of a working fluid line that passes through the base body. The control fluid valve and the working fluid valve are electrically connected to a control device that electrically controls the control fluid valve and the working fluid valve. Moreover, a membrane pump is provided that has an actuating device and a membrane pump device.

Abstract: A diaphragm pump having a body including a suction connection and a discharge connection, a suction valve and a discharge valve; a control chamber in which the diaphragm is disposed, and a working chamber located on the side of the diaphragm opposite the control chamber; a control pipe suitable for linking the control chamber to a control connection of the body, the control pipe configured to alternately apply a vacuum and a pressure on the diaphragm; the body includes a housing oriented transversely relative to the control pipe, the housing being open towards the outside at one end, and closed at the other end by a bottom including a suction opening and a discharge opening, the diaphragm being positioned close to the bottom, and held by a cap engaged in the housing, the cap having a recess forming the control chamber, linked to a passage communicating with the control pipe.

Abstract: A pump system comprises an electric motor, a pump, a converter and a controller. The electric motor has a rotational output shaft that is rotatable in a first rotational direction and an opposite second rotational direction. The pump has a linearly displaceable input shaft that is movable in a first linear direction and an opposite second linear direction. The converter couples the output shaft to the input shaft such that rotation of the output shaft in the first rotational direction translates the input shaft in the first linear direction, and rotation of the output shaft in the second rotational direction translates the input shaft in the second linear direction. The controller repeatedly reverses rotation of the output shaft to produce reciprocating motion of the input shaft.

Abstract: An irrigation system including a reservoir with an inlet adapted to guide liquid into the reservoir, the inlet defining a closure for closing the inlet, an insertion member defining an insertion end sized for insertion into a body cavity of a human being, the insertion member defining at least one opening, and a liquid tube fluidly connecting the reservoir with the insertion member, at least one of the reservoir and the insertion member being permanently fastened to the liquid tube and further including an electrical pump adapted to pump liquid from the reservoir and out through the at least one opening of the insertion member, the electrical pump adapted to be separable from the system.

Abstract: Some injectors of the invention may include a fluid drive responsive to pressure of a working fluid (e.g., liquid, pneumatic, or both) to impart a sequence of forces to drive a delivery device (e.g., a syringe) to deliver a medical fluid (e.g., a contrast agent, a radiopharmaceutical, a drug, or a combination thereof). Some injectors may include a multimedia tube configured to pass a working fluid (e.g., air) and a light signal (e.g., infrared). Some injectors may include a peristaltic drive responsive to pressure of a working fluid.

Abstract: The present invention relates to pump systems and engine systems having graphene drums. In embodiments of the invention, the graphene drum can be utilized in the main chambers and/or valves of the pumps and engines.

Abstract: An improved fire pump for a firefighting vehicle is provided. The fire pump is capable of being positioned at least partially under a rear portion of the cab of a firefighting vehicle. The pump includes a shaft, an impeller supported by the shaft, and a pump housing which encloses the impeller and supports the shaft for rotation about an axis. The housing includes a fluid inlet configured to direct a fluid into the housing along a path generally parallel to the axis. The housing also includes two fluid outlets each at a periphery of the impeller and configured to direct the fluid from the housing along respective paths generally perpendicular to the axis.

Abstract: In a mixing pump device (1), during an suctioning step a stepping motor (12) rotates in a first direction, so that during this time, a plurality of fluids can be drawn in prescribed proportions into a pump chamber (2), by sequentially opening and closing active valves (5a, 5b) situated in inflow passages (3a, 3b) while active valves (6a, 6b) situated in outflow passages (4a, 4b) are in a closed state. During the discharging step the stepping motor (12) rotates in a second direction, so that during this time, a mixed fluid can be discharged from the pump chamber (2) simply by sequentially opening the active valves (6a, 6b) situated in the outflow passages (4a, 4b), while the active valves (5a, 5b) situated in the inflow passages (3a, 3b) are in a closed state. It is possible thereby to achieve a mixing pump device capable of mixing a plurality of fluids in prescribed proportions, without detecting the operating stage of the pump.

Abstract: An air pump is capable of inflating an inflatable object, and includes a housing unit, a motor and a fan. The motor and the fan are disposed within the housing unit. The housing unit is formed with a pair of first and second intake port units and an exhaust port unit. The fan includes a middle plate connected fixedly to a driving shaft of the motor, and a pair of first and second fan blade units extending respectively from two opposite side surfaces of the middle plate. Air is sucked into the housing unit by the first and second fan blade units through the first and second intake port units, respectively, and is subsequently forced out of the housing unit by the first and second fan blade units through the exhaust port unit.

Abstract: A structure for reducing a refrigerant flow loss in a compressor includes a refrigerant flow resistance reducing unit to reduce a refrigerant channel resistance at a lower surface of a rotor facing a compression mechanism unit. When the high temperature and high pressure refrigerant gas discharged from the compression mechanism unit flows to the discharge pipe through the refrigerant passage including the gap between the rotor and the stator of the electric mechanism unit, the flow resistance of the refrigerant gas is reduced. Therefore, since the refrigerant can flow smoothly, a flow loss of the refrigerant can be reduced and, as a noise generation is reduced, a reliability can be heightened.

Abstract: A method is provided for controlling a torque output of an hydrostatic motor in fluid communication with a variable displacement pump. At least one of the motor and pump has variable displacement capabilities. The method includes monitoring at least one motor condition of the hydrostatic motor and determining a displacement signal corresponding to the monitored motor condition. The variable displacement capabilities are controlled based on the displacement signal to reduce a torque ripple in the torque output of the hydrostatic motor.

Abstract: A two-cylinder thick-matter pump for continuous delivery of thick matter is characterized in that a reversing valve (5) has a diverter housing (8, 8′) with at least four openings (a-b), the diverter (6, 6′) disposed in the diverter housing (8, 8′) is swiveled with its outlet opening in front of the cylinder openings and has an inlet opening (RE) which is firmly connected with the suction pipe (3), the cavity (H) in the diverter housing (8, 8′) being constantly under delivery pressure, and at least one shut-off element (10) being provided for closing the suction pipe (3) and/or the first and/or second openings (a , b) of the diverter housing (8, 8′).

Abstract: The silencer 22 having an enclosed tank 23 includes an inlet port 24 positioned at one side of the tank 23, a discharge port 25 positioned at another side of the tank 23, and a partition plate 26 separating an inner space of the tank 23 into an inlet side chamber and an outlet side chamber. The partition plate 26 is formed with an orifice 27 communicating the separated chambers with each other. The partition plate 26 is also provided with a drain hole 28 communicating with both the chambers. The tank 23 is located at a position lower than the vacuum pump 12. A drain discharge line 33 may communicate with a lower portion of a casing of the vacuum pump 12. Furthermore, the tank may have a cooling water jacket 31 for cooling a wall of the tank 23.

Abstract: A compression mechanism is provided, in a casing, and operatively coupled via a drive shaft 17 to an electric motor 21 accommodated in a motor chamber 15 within the casing, so that power can be transmitted. An in-shaft bore 17A is formed in the drive shaft and a first bifurcated hole 17B is formed for communicating the in-shaft bore 17A to the motor chamber 15. The in-shaft bore 17A is communicated to the suction chamber 31 via a second collecting hole 13F, the collecting chamber 13D and a suction communication hole 13G formed in a cylinder block 13. Thereby, part of the refrigerant sucked in the casing is introduced to the compression mechanism through a gap between a stator 19 and a rotor 20, and the remainder of the refrigerant is introduced to the compression mechanism without being used for cooling the electric motor 21.

Abstract: A system and method for controlling operation of a sludge material handling system is disclosed. The sludge material handling system includes a positive displacement piston/cylinder pump, a sludge material feed system which delivers sludge material to the pump, and a sludge material disposal system which receives and disposes of sludge material from the pump. A first parameter is sensed, the first parameter bearing a known relationship to an actual volume of sludge material delivered during a pumping cycle. An output value is determined from the first parameter. A control signal is provided as a function of the output value.

Abstract: A double piston pump mechanism includes two pistons operated out-of-phase by respective fluid-actuated cylinders. The pistons suck-in fluid through suction valves and discharge pressurized fluid through pressure valves. The actuation of the cylinders is regulated by two change-over valves which are mechanically connected to respective cylinders. Each change-over valve is actuated when its respective cylinder reaches a fully extended position or a fully retracted position. The change-over valves are connected to a control mechanism which operates to reverse the direction of actuating fluid supplied to the cylinders, the suction valves, and the pressure valves only in response to actuation of both of the change-over valves.

Abstract: A compressor is provided with a housing having a boss portion forming a central bore through which a drive shaft is passed, and a clutch has a rotor rotatably supported by the boss portion through a ball bearing. An armature thereof has a frictional surface facing, with a small gap therebetween, a frictional surface of the rotor, and a holder plate is connected to a surface of the armature opposite that frictional surface by rivets. The holder plate has a tubular portion connected to a hub via an annular cushion rubber, and the hub is in spline engagement with the drive shaft of the compressor. An oil sleeve is oil-tightly fitted to the boss portion and axially passed through a central opening of a cover located on the surface of the armature, opposite the frictional surface thereof. The oil sleeve has at its free end an annular flange shaped oil cut portion radially faced with the cover.

Abstract: A valve for use with a first working fluid conduit and a second working fluid conduit, the valve includes a valve body with a valve bore formed therein. A piston is slidably disposed within the valve body. There is a first opening and a second opening formed within and defined by the valve body. The first opening is in communication with the first working fluid conduit and the second opening is in communication with the second working fluid conduit. Displacement of the piston in a first direction to a first position results in restriction of working fluid passage through the second working fluid conduit. Displacement of the piston in a second direction, opposed to the first direction, to a second position results in restriction of working fluid passage through the first working fluid conduit. There is a spring which biases the piston into the second position.

Abstract: Blending and pumping systems for accurately delivering desired amounts of processing fluids, particularly for use in semiconductor processing and semiconductor processors. Thee blending systems include one or more supply tanks from which a processing fluid is accurately pumped using the novel metering pump and associated pumping and blending methods. The blending systems preferably include a recycle line which includes a control valve which is controlled to recycle process fluid during an initial startup period. The outflow from the pump is preferably totally recycled during this startup period by blocking flow of process fluid to the blending container. The metering pump includes a pump housing having a pumping chamber which is partially defined by a displacement member, such as a flexible bellows structure. The pumping chamber is isolated from inlet and outlet via inlet and outlet valves, respectively.

Abstract: Provided are a pair of pumps, each of which comprises a bellows having an intake inlet and a discharge outlet, a reciprocating drive means for contraction and expansion movements of the bellows, and a couple of electro-magnetic on-off valves disposed respectively in the intake inlet side and discharge outlet side of the bellows, so that, during the contracting motion of the bellows, the electro-magnetic on-off valve in the intake inlet side becomes closed while the electro-magnetic on-off valve in the discharge outlet side becomes open, and during the expanding motion of the bellows, the electro-magnetic on-off valve in the intake inlet side becomes open while the electro-magnetic on-off valve in the discharge outlet side becomes closed. The paired pumps perform the discharge motions alternately. The discharge outlets of the pumps at their ends are fluidly connected via a directional valve with a discharging gun.

Abstract: An automobile cleaning system comprises a source of cleaning fluid and control apparatus connected to the source and responsive to a control input for pressurized output of the cleaning fluid. The system has also a source of pressurized medium, such as positively or negatively (vacuum) pressurized air. A portable unit for issuance of the pressurized cleaning fluid has a first channel with an input port connected to the control apparatus for receipt of the pressurized cleaning fluid and an output port for fluid issuance and has a second channel with an input port connected to the pressurized air source and an output port at a surface of the portable unit for closure upon blockage by a user of the system. A conduit is provided to conduct indication of second channel blockage to the control apparatus as the control input thereto.

Abstract: Inside the hermetic shell of a scroll compressor, a normally closed solenoid valve seats against the back side of a stationary scroll plate to close a discharge opening through the plate. A coil circuit that actuates the valve has an electrical resistance that increases with temperature. The temperature dependent resistance allows the coil circuit to also function as a discharge temperature sensor. Should the discharge gas over-heat, the compressor motor and the valve are de-energized in response to the resistance exceeding a predetermined limit. The closed valve prevents backflow from rapidly reversing the rotational direction of the compressor, which can be extremely noisy and damaging to the compressor. Both the valve and the compressor motor are energized at the same time, regardless of the compressor's direction of rotation.

Abstract: A driver for use in an infusion pumping cassette having an elongated valve actuator which operates a valve controlling the flow of fluid through the cassette, a bracket having a first arm pivotally secured to one end of the valve actuator and a second arm, a cam driveably engaging the second arm, a motor which drives the cam and a positioner which monitors the rotational position of the cam.

Abstract: A high pressure metering pump has a duty cycle consisting of an aspiration portion where liquid is aspirated into a pumping chamber, a compression portion where the aspirated liquid is compressed to feed pressure, a feed portion where a part of the compressed liquid is expelled out of the pumping chamber, and a decompression portion where the liquid remaining in the pumping chamber is expanded to aspiration pressure. A measurement and control apparatus for the pump comprises a controller for adjusting and keeping constant the mean flow rate of the pumped liquid on the aspiration side or on the high pressure side of the pump. The apparatus further comprises a detector for detecting the transition point between the compression and feed portions and/or between the decompression and aspiration portions. The detector derives a control signal for the pump speed and for the optimal opening instant of an externally actuated input valve of the pump from the phase relationships of said transitions.

Abstract: A suck-back pump for preventing any additional amount of liquid from dropping out of the tip of a delivery pipe, after a predetermined amount of liquid has been delivered from the delivery pipe. The suck-back pump includes inlet and outlet ports for liquid, first and second chamber respectively connected with the inlet and outlet ports, a communicating passage for connecting the first and second chambers with each other, a shut-off valve movable to close the communicating passage, and a suction element movable to change the volume of the second chamber. The actuation of the suction element is retarded so that it is actuated after the shut-off valve has been actuated.

Abstract: A positive displacement pump utilizes at least three driven displacer valves and a plurality of driving membranes and at least one pumping membrane to withdraw minute quantities of corrosive fluid from a drum and discharge same from a spray nozzle. The pump is submerged within the fluid to be pumped and is driven by a remotely positioned pneumatic pulse generator comprising pneumatic logic circuitry. The driven displacer valves operate in a particular sequence to draw fluid into the pump body, advance same from pumping chamber to pumping chamber within the pump body, and then discharge same at a constant rate of discrete pulses through an outlet port. The pulse generator and logic circuitry provide the control pulses for operating the displacer valves at the proper times in the operational cycle. The delivery characteristics of the instant pump far exceed the performance capabilities of conventional pumps utilized for similar purposes.

Abstract: A pressure controller includes a set point switch mechanism by which a selectable pressure to be maintained in a pressure vessel can be set. The actual pressure in the pressure vessel is detected and converted into a corresponding electrical signal by a suitable pressure transducer. Electrical signals from the set point switch mechanism and the transducer are utilized by a computer to generate control signals for controlling a volume adjustment mechanism which adjusts the effective volume of the pressure vessel and adjusts the quantity of pressurizing fluid disposed in the vessel. The volume adjustment mechanism includes a piston disposed in a cavity which is connectable with the chamber of the pressure vessel. The volume adjustment mechanism also includes a stepper motor which can be moved in precise increments to adjust the position of the piston in the cavity.

Abstract: An automatic operating system for a pump driven by an internal combustion engine is disclosed in which the engine is kept in operation at a low and economical speed automatically disconnecting the pump from the engine when delivery pressure from the pump is not required and connecting the pump automatically when delivery pressure from the pump is required. Such automatic control is effected by a valve block in which a safety valve is incorporated, the movement of the valve body of which is utilized to control the connection and disconnection of the pump, the movement of the valve body being dependent on the pressure in the discharge line of the pump.

Abstract: When a valve-controlled pump is to produce either vacuum or pressure at a pump outlet 9 as a function of its direction of rotation it is necessary that a 3/2-way valve be switched as a function of the direction of rotation of the motor of the pump. In accordance with the invention this is effected by a direction detection device on the motor (1) which is coupled with the motor for the control of the 3/2-way valve. The direction detection device is formed in the manner that the motor housing of the motor (1) is mounted for rotation and is provided at its end with a structural part (11) having a control kidney (10) which is movable over a control surface (7). Since the motor housing must take up the counter moment when the motor is rotating, the control kidney (10) shifts upon the starting of the motor (1) into one of its two end positions depending on the direction of rotation of the motor (1), thereby causing the pump outlet (9) to be connected alternatively to pressure or vacuum.

Abstract: Concrete is transmitted from a hopper forming a part of a mobile concrete pumping apparatus to the deposit site through a flow line having a Y-pipe inlet. The pumping apparatus includes two piston-cylinder concrete pumps mounted in side-by-side relationship adjacent the hopper, which has an auger to rapidly charge a pump with concrete through one of two discharge pipes. Each pump is pivotally mounted, to locate the cylinder aligned with the discharge pipe or with one inlet of the Y-pipe inlet. Each pump has a valve plate pivoting with the cylinder to alternately close the hopper opening and the inlet line. Hydraulic cylinder units are coupled to the valve plates to pivot the pumps. A floating valve plate has coupling pipes attached to the hopper and a hydraulic cylinder urges the same into sliding sealing engagement with the rotating valve plate.

Abstract: A piezoelectric driven variable volume having a chamber pump with a flexible tube and a non-compressible fluid therein. Solenoid operated valves are associated with the inlet and outlet of the flexible tube. A control circuit sequences the valves and the piezoelectric drive to pump small volumes of liquid through the flexible tube by a diaphragm-type action.

Abstract: A power-assisted valve is provided which is particularly effective for systems handling viscous materials, such as certain metering systems. The check valve operates effectively even with highly-filled viscous resins used in such systems. The valve includes a valve seat and a valve ball which can be urged toward the valve seat to a closed position by a fluid-powered cylinder and piston. The piston rod is separate from the valve ball so that the ball can rotate relative to the valve seat.

Abstract: A multiple pumping chamber pump in which the pressures in at least two of said chambers are equal for at least a portion of their pumping cycles, maintains a constant flow of pumped material by utilizing control means that selectively and continually replaces one material pumping chamber with another after the pressures in both of said chambers have equalized and after the outputs of said chambers have been connected to a common output conduit, by gradually and simultaneously causing a decrease in the pumping rate of material from one of said compression chambers and, to the same extent, a corresponding increase in the pumping rate of material from another of said chambers until the material pumping rate from one of said chambers is reduced from its normal pumping rate to zero and the pumping rate from the other of said chambers has been increased to the said normal pumping rate from the said chamber that had its flow rate reduced to zero.

Abstract: A suction control valve adapted to be connected to the suction side of a compressor and comprising a valve housing, in which a valve seat is formed, which co-operates with a valve body which, in its opened position, brings the suction side of the compressor into open communication with the atmosphere. Said valve body is attached to a valve stem which, in its longitudinal direction, is slidably guided in the valve housing for the displacement of the valve body from the closed position to the open position and vice versa. A continuous bore in the valve stem is at one end in open communication with the suction side of the compressor, and opens at the other end into a diaphragm chamber, which is located on the side of a diaphragm facing away from the valve body, which diaphragm is fixed to the valve stem, while the diaphragm chamber is connected to a conduit, which accommodates a stop valve.

Abstract: A reversible fluid pump is driven by a reversible electric motor under the control of a three position toggle switch wired for off, forward and reverse. One port of the pump is connected to a four position valve, one position of which is off. A hose to a drain receptacle or to an oil supply connects to the other port of the pump and hoses from engine crankcases connect to the three active ports of the valve. A two position valve adapts the pump for single engine use. The handle for selectively positioning each of the valves extends perpendicularly to the valve stem and when in off position aligns with the toggle. Safety latches of alternate constructions, with or without thumb screw tightening means, are each pivoted to the handle to engage the toggle and retain both the valve and toggle in off position when the system is not in use.

Abstract: This invention provides a container delivery system for vending apparatus for vending containers. The delivery system comprises a container store and dispenser, an arm moveable in to and out of the path of travel of a cup dispensed by the container dispenser for receiving the dispensed container to support it temporarily at an angle to its path of travel and an ingredient dispenser mounted to one side of the container dispenser for dispensing a charge of material into the angled container and a guide to guide the container after it has been released by the arm to a discharge part formed in the body of the vending apparatus.

Abstract: A constant-volume increment pipetting arrangement for use particularly in connection with analysis of minute specimen volumes of biological fluids. The arrangement, which is designed to have a very low inertia factor, comprises a pumping unit having a pair of two-port valves with a duct running between a port from each valve, wherein at least a portion of the duct wall is movable to provide a variable volume pipetting chamber. The second port of one valve serves as the intake port for the fluid to be pipetted and the remaining port of the other valve serves as the delivery port. Three reciprocating drive elements are provided, connected one each to the valves and to the movable portion of the duct wall. Associated with the drive elements is a sequential control means, wherein the control means portion for the drive element connected to the moving portion of the duct wall constitutes an electromagnet arrangement energizable by a periodic supply.

Abstract: A concrete pumping unit comprising a pair of parallel piston pumps, alternately placed in communication with a concrete supply conduit and with a concrete delivery pipe, through a single baffle blade valve and respectively driven by coaxial fluid pressure piston cylinders is disclosed. The cylinders are interlocked with each other by a pipe which places in communication the chambers of said fluid pressure cylinders, opposite to the chambers in which the pressurized fluid is supplied and discharged through orifices near the ends of said cylinders. A hydraulic circuit is provided for placing a fluid supply pump, in communication with the fluid pressure piston cylinder performing the suction phase, while the orifice of the other fluid pressure piston cylinder is placed in communication through another circuit including, a four-way changeover electro-valve and an actuator distributor device with a discharge reservoir.

Abstract: A double acting metering pump is disclosed for use in apparatus to prepare matrices containing frangible particulate material. The double acting pump provides a metered output of matrix containing frangible particulate material which is mixed with a parent matrix from an extruding apparatus in a downstream static mixer. The pump includes pneumatically actuated valves that control the flow of matrix to each of two alternately discharged pumping chambers. The pump is facilely disassembled for cleaning and is surrounded by a heating jacket to maintain an essentially uniform temperature in the matrix during pumping.

Abstract: This invention provides a faucet assembly which includes a fluid passageway with valve means adapted to close and open the passageway, and a shaft which operates the valve means by rotating. Resilient biasing means are provided to the form of a spring-biased finger to induce the shaft to rotate in the direction closing the valve means whenever the shaft is less than a given angle away from the fully closed position. This given angle corresponds to a condition in which the passageway is at least partly opened.

Abstract: A reciprocating infusion pump is presented having a pair of syringes activated by individual actuating cylinders. The actuating cylinders are interconnected with a hydraulic fluid, and the cylinders and alternately pneumatically actuated whereby the cylinders alternately act as drive and follower cylinders whereby one syringe delivers fluid to a patient while the other is refilled from a reservoir. A directional adapter set is affirmatively actuated in synchronism with the actuating cylinders to control the direction of fluid flow from the reservoir to the syringes and from the syringes to the patient.

Abstract: A pumping apparatus for wet concrete and the like comprising a pair of piston pumps having parallel axes, interlocked to one another and operating in phase opposition, the orifices of which are alternatively put in communication one with the conduit feeding the wet concrete and the other with the delivery conduit and vice versa by means of a reciprocally movable baffle blade valve having two operative limit positions, characterized by the fact that the pump pistons are each actuated by a single-acting jack, being provided means to at first move the baffle valve into either of its operative positions by means of a hydraulic control device, and then to actuate the jack which is about to begin its intake stroke only when the baffle blade valve has reached one of the limit positions, and to reverse the position of said baffle valve into its second limit position before the beginning of the compression stroke of the pump actuated by said jack and vice versa, and means for interlocking the movements of the jacks, a

Abstract: Apparatus for fluid flow control in a parenteral administration system, utilizing a syringe pump operated by a motor to repetitively fill and empty a syringe cartridge over a plurality of operational cycles of successive fill stroke and pump stroke periods. The apparatus repetitively and sequentially opens and closes a pair of intake and output I.V. tubes communicating with a syringe, the tubes alternating opened and closed states, one tube always being open while the other is closed, by means of a pair of L-shaped pivotal tube pinchers, one pincher controlling each I.V. tube, each pincher being normally spring biased to the tube clamping shut-off state. The tube pinchers are alternately pivoted to a non-clamping, tube-open position by a spring biased, intermittent motion, reciprocating slide bar under the control of a reversible, rotating cam, the cam being driven by the same motor as that used to drive the piston of the syringe through its fill and pump strokes.

Abstract: Apparatus is disclosed for actuating hydraulic motor control valves in a predetermined timed relationship relative to a pump inlet valve, wherein the pump is connected to and driven by the hydraulic motor, to improve the metering capabilities of the motor-pump combination.

Abstract: A pneumatically controlled liquid transfer system for delivering a liquid from a source to a delivery location, said liquid source being provided with a pneumatic cylinder for driving the liquid from said source, a pneumatically operated pinch valve of the make-before-break type and flexible conduit paths leading through the valve to the delivery location. The make-before-break pinch valve comprises a valve shell having two pistons movable laterally therein. The shell has a window. One piston has a yoke, each arm thereof having a passageway, one aligned with the other. A stop extends between the arms of the yoke. One of the flexible conduits is arranged through the window between the first piston and the yoke and the other flexible conduit is arranged also through the window but within the aligned passageways and between the piston and post. The second piston is spring biased to bear against the second conduit to place same in a normally closed condition. The first conduit is normally open.