Abstract: A pump system, particularly suitable for pumping wet mixes and slurries, achieves an output of pumped material substantially free from pulsations or fluctuations by control movement of power pistons (12A,12B) within power cylinders (10A, 10B). The power pistons (12A,12B) are connected by piston rods (14A,14B) to pumping pistons (16A,16B) which suck material to be pumped in through valves (20A,20B) and out through valves (22A,22B) into a delivery pipe (26). A closed loop (32) connects annular chambers (13A,13B) of the power cylinders (10A,10B), and a continuously operating pump (P2) feeds the closed loop (32). The power pistons (12A,12B) on their suction strokes move faster than on the delivery strokes, whereby one or other or both pistons (12A,12B) are always moving forwards.

Abstract: A hydraulically actuated multi-cylinder reciprocating piston pump includes two double acting cylinder and piston type hydraulic actuators each connected to a working fluid piston and hydraulically interconnected by a control circuit to provide alternate delivery and suction strokes to the respective working fluid pistons. The piston rod chambers of the hydraulic power actuators are interconnected to transfer operating fluid therebetween to drive the actuating pistons on their return strokes. Each cylinder actuator is provided with a sleeve type pilot valve interposed in a hydraulic circuit including a main spool type control or distributing valve for operating the cylinder actuators in timed relation to each other. The hydraulic circuit includes a main high pressure source of actuator operating fluid and a lower pressure source of pilot actuator and leakage make up fluid for the actuator piston transfer circuit.

Abstract: A quadraplex pumping unit for use as a mud pump, an intensifier, or as a pump for abrasive fluids or the like includes four rams and four ram operating pistons. A control valve arrangement provides for pressure equalization and energy transfer from a cylinder which has just extended in a working stroke to a companion cylinder which has just returned to its retracted to rest position, to conserve energy and reduce the thermal burden on the hydraulic system. The valve arrangement further provides for prepressurization, after pressure equalization, prior to an extending stroke.

Abstract: A concrete pump comprises a pair of separate pump assemblies each having a cylinder, a piston subdividing same into a piston-side front compartment and a rod-side rear compartment, and a piston rod connected to the respective piston and extending out of the respective cylinder through the respective rod-side rear compartment. The pump also has a liquid supply having a high-pressure side and a low-pressure side for supplying liquid under high pressure at the high-pressure side and for taking in liquid at the low-pressure side.

Abstract: A pump (10) is disclosed for use in pumping a fluid (14) from a borehole (12) to the surface. The pump includes a first and second pumping string (20, 22) extending into the borehole and a return string (26) extending from the borehole. First and second pistons (82, 94) are slidably mounted at the ends of the first and second puming strings within the borehole, respectively for reciprocation between extended and retracted positions. First and second pumping cylinders (56, 64) are secured in fixed relation to the first and second pumping strings (20, 22) so that the first and second pistons (82, 94) are slidable therein. The pistons and pumping cylinders define first and second pumping chambers (92, 104). Each of the first and second pistons includes a gear rack (88, 100) having teeth meshing with the teeth on a stroke return gear (106).

Abstract: An apparatus is provided for making waves in bodies of water used for swimming having a multicompartmented chamber with at least one set of separate paired compartments open in a nonintercommunicating lower portion for separate reception of water therewithin from a body of water, and closed in an intercommunicating upper portion in a manner to provide a fluid-tight upper portion confining therewithin a volume of fluid that is common to each pair of compartments; and at least one pair of pistons, each disposed in separate paired compartments in the chamber, each piston being mounted across its compartment for reciprocation in alternating power and suction strokes and arranged for fluid-pressure-induced interreaction with the other piston in balanced strokes; each piston having an upper face with a pressure-receiving surface responding to fluid pressure in the upper portion of its compartment, and a lower face with a pressure-receiving surface responding to water pressure in the lower portion of its compartment

Abstract: An apparatus is provided for making waves in bodies of water used for swimming, having a plurality of hollow open-bottom pistons mounted for reciprocation in alternating power and suction strokes in which the movement of each piston engaged in a power stroke is opposed to the movement of an adjacent piston engaged in a suction stroke; each piston confining a gas cushion between the top and any water within the lower portion of the piston that is under a superatmospheric pressure during a power stroke of the piston, and under a subatmospheric pressure during a suction stroke of the piston; whereby on the suction stroke each piston draws water into its interior via its passage and port from the body of water, and on the power stroke each piston pushes water from its interior via its passage and port back into the body of water, the resulting alternating pulses of water flow generating waves in the body of water.

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 positive displacement pump or motor having a plurality of cylinders in a rotatable cylinder block, the axes of the cylinders being parallel to the axis of rotation of the block, and stationary inlet and discharge ports which overlap openings in the cylinders so that port areas are constantly open to permit constant flow into the cylinders and constant flow out of the cylinders.

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