Abstract: A full flow tubing stationary valve pump apparatus includes an cuter annulus barrel, an inner working barrel positioned in radially inwardly spaced relation from the outer annular barrel to define a vertical flow annulus therebetween, an elongated inner plunger disposed within and vertically movable by upstrokes and downstrokes relative to the inner working barrel, a lower intake valve assembly disposed within and supported by the outer annulus barrel below the inner plunger, and an upper discharge valve assembly disposed within and supported by the outer annular barrel below the inner plunger and above the lower intake valve assembly.

Abstract: A variable delivery liquid pump system includes a housing defining an inlet, an outlet and a plunger bore. A rotating shaft includes a cam that defines a fixed displacement distance with each rotation of the shaft. A plunger is slidably positioned in the plunger bore. A supply of liquid at a supply pressure is attached to the inlet by a supply passage. An output control mechanism includes an electronically-controlled flow restriction valve positioned in the supply passage. The plunger retracts less than the fixed displacement distance of the cam during each rotation of the shaft when the flow restriction valve is at least partially closed. The variable delivery pump is particularly suited for use in a hydraulically-actuated fuel injection system.

Abstract: A peristaltic pump delivering a medicant through a plastic tube with an appropriate wall thickness to withstand external rubbing contact with the rotating rotor of the pump, in which downstream of the rotor a tubing length is used in the plastic tube having a thinner wall thickness so that when a downstream occulsion is detected, the pressure build-up transmitted upstream to the tubing length more readily causes it to undergo an expansion radially because of its thinner wall to actuate an on-off switch of the peristaltic pump.

Abstract: A variable displacement axial piston pump (11) including a housing (19 and a back plate (25), with a cylinder barrel (29) rotating therein, and defining a plurality of cylinders (31), and a piston (33) reciprocably disposed in each one. There is a tiltable swashplate (37) whereby the displacement of the pump can be varied. In one embodiment, an open center shuttle assembly (71) is disposed in the swashplate (37), and interconnects the high and low pressure paths of the pump to provide a wide neutral band. When the pump is displaced intentionally, the resulting pressure in the high pressure path biases the shuttle to a closed position, permitting normal operation of the pump. In a second embodiment, the shuttle assembly (71) is disposed in the back plate (25), and is accompanied by a load holding valve assembly (105), which insures that, when the vehicle is on an incline, the fluid pumped by the propel motors won't flow through the shuttle assembly (71).