Abstract: A drilling device for drilling a borehole and comprising a drilling tool, a drill pipe extending into the borehole for conducting a flow of liquid thereinto for generating an oscillating percussion force applied to the drilling tool, a longitudinally movable impulse tube located below a lower end of the drill tube, a throttle located between a lower mouth of the drill tube and an upper mouth of the impulse tube for controlling a ration of flow portion of the liquid outside and inside the impulse tube in accordance with longitudinal position thereof, and a spring-loaded thrust valve for controlling the flow of liquid inside the tube.

Abstract: A pumping system for water in a pit comprises a feeding unit to be installed above the ground and a suction ram assembly to be immerged into water partially filling the pit. The suction ram assembly has a ram valve (4a, 4b) and a foot valve (12, 13) which are connected to the feeding unit through the concentric arrangement of a feeding hose (1) and a riser pipe (2). The ram valve comprises two annular coaxial sleeve parts (4a, 4b) each having a valve seat (7, 8), and annularly surrounds the riser pipe (2). An electrolytical gas cushion vessel (17) having an electrode (18) is attached to the riser pipe (2) which forms an associated electrode. The vessel (17) also contains a float (21) which is connected to the ram valve (4a, 4b) over cables (22). The unit of the riser pipe (2), the ram valve (4a, 4b), the foot valve (12, 13) and the vessel (17) is plugged into a funnel-shaped sleeve (15) which is fixed to the feeding hose (1).

Abstract: A liquid feed device for conducting a pressurized medium from a stationary housing to a rotatable component is so constructed that the applied force of a sealing surface of a sliding shoe of the housing on the running surface of the movable structural component is regulated so that on the one hand an effective seal between the sealing surface and the running surface independent of the operating conditions of the system is guaranteed and on the other hand the frictional forces operating are kept as small as possible.

Abstract: A controllable two-way valve for pressure and/or flow control uses a cup-shaped piston, the bottom of which forms a large effective surface area exposed to a control flow through a slit which cooperates with an edge of the slider also serving to define the main flow cross section between an inlet and an outlet. A stationary compensating piston within this slider vents the interior of the slider and a control valve set connected to a spring chamber through which the control flow passes regulates the pressure applied to the slider in the spring compartment.

Abstract: A hydrostatic clutch of the type in which an input shaft has a casing in which a positive displacement gear pump is received and an output shaft is connected to the gear pump. According to the invention the gear pump includes a gear pump body provided with intake and pressure passages, the body being limitedly rotatable in the casing so that upon reversal of the rotation of the input shaft, the passages of the body will switch over as to communication with openings of the casing and thereby reverse the pump.

Abstract: The apparatus serves to pass an arbitrary pressure medium from a stationary housing (1) to a rotating shaft (4) provided with supply bores (3) in such a manner that there is little leakage or noise and the apparatus is ventable. Sliding pads (8) rest on a lateral contact face (12) of an indexing ring (13) rotating with the shaft (4) and axially displaceable thereon. The sliding pads (8) are supported in an axially displaceable manner on hollow pistons (7) secured to the housing (1). The indexing ring (13) has pins (19) for guiding and coupling it, which are supported in axial bores (21), provided with springs (22), of a shaft ring (16) secured on the shaft (4). The indexing ring (13) has axial check valves (23), each having a valve plug (25) whose end face (29) is located in the plane of the contact face (12) of the indexing ring (13) for the sliding pads (8).

Abstract: A decanter centrifuge has a drum driven by a main driving motor via belts and a worm gear located in the drum so that it can rotate. The worm gear is driven by a hydraulic motor with a differential rate of rotation which rotates with the drum, thus providing a slip drive unit. A hydrostatic coupling is connected between the main drive motor and the belt drive of the drum. A pressure line of the pump of the hydrostatic coupling is connected hydraulically with the feed line of the hydraulic motor of the worm gear through a flow-control valve. With this arrangement, only a single pump, that is, the pump of the hydrostatic coupling is required to accelerate the drum and regulate the rate of rotation of the drum on the one hand, and simultaneously to feed the slip drive unit, on the other.

Abstract: A cylinder block (1) has radial bores (3) of rectangular cross section with a piston comprising a hollow roller (5) and a piston cap (4). The rollers (5) are supported on an outer cam (2). The piston caps (4) are periodically exposed to the pressure (p) of a medium which is delivered to them via channels (11, 13) in side sealing plates (6,7) and via the hollow spaces (10) of the rollers (5). The piston caps (4) are provided with sealing strips (17, 18) resting on bore walls (8, 9) and with support ribs (19, 20). Each roller (5), with the two associated bore walls (8, 9), forms gaps each of which, together with the one sealing strip (17, 18) and bore wall (8, 9) define an intermediate chamber (p.sub.c, p.sub.o). From the intermediate chambers (p.sub.c, p.sub.o) channels (25, 26) lead in the piston cap (4) to the support faces ( 23, 24) of the support ribs (19, 20).

Abstract: To control the flow of fluid from a positive displacement pump to a consumer line, a rotating shutter periodically opens return flow nozzles which permit the pressure-free return of the pumped fluid to a fluid reservoir. In order to provide hydraulic balancing of the forces on the shutter, the return flow nozzles are disposed symmetrically with respect to the axis of the rotating shutter. Pressure peaks which occur when the return flow nozzles are closed cause undesirable noise generation and these pressure peaks are reduced by the disposition of separate check valves associated with each of the symmetric flow conduits. The use of separate check valves reduces the length of the fluid column which must be accelerated upon nozzle closure. To reduce the opening stroke of the check valve, the edge of the valve seat meanders thereby extending its effective length. Axial play of the rotating shutter is controlled by the disposition of a spring loaded glide block.

Abstract: A multi-way rotary valve for fluid media having a distributor block and rotatable distributor disc, separated therefrom by a gap of variable size and provided with a pintle for rotation is provided with a bleeder throttle having a spring biased ball check valve so that the disc is rotatable when the turning torque is higher than the torque produced by the spring.

Abstract: An input shaft is provided with a cylinder and an output shaft is provided with a rotary wing piston in the cylinder. The rotary wing piston has two arms and together with two diametrically opposite cylinder cams forms two pairs of pressure chambers. Depending on the direction of torque, a pressure medium is supplied to one of the pairs of pressure chambers by means of two three way valves provided on the cylinder wall. The slits between the frontal surfaces of the cams and the opposing surfaces of the rotary wing piston throttle the outflow of the pressure medium out of the chamber pair. As a result of the automatically adjusting equilibrium between the applied torque and the compressive force in the pressure chamber pair, the pressure of the pressure medium supplied by a pump is a measurement for the magnitude of the transferred torque and can be read on a manometer.

Abstract: A hydraulic push drive for pusher centrifuges, having a rotating body with a cylindrical bore. The rotating body is provided with a piston rod and piston body therein. A rotary control valve is disposed in the rotating body. The rotary control valve is driven by a hydraulic motor and controls the application of pressure. A valve is slideably mounted in a coaxial bore in the piston rod in order to control the stroke center of the piston by pulse duration modulation of a controlled leakage flow.

Abstract: The flow of fluid from a constant output positive displacement pump entering an outlet line directed to a consumer may be varied by periodically interrupting this flow and directing the flow instead into a zero pressure pump reservoir. This interruption is accomplished by a rotary shutter which periodically and alternately opens and closes the line to the reservoir. The line from the pump flows into two nozzles opening into opposite sides of the rotary shutter and directed toward one another. The rotary shutter comprises a shaft with two raised ribs thereon positioned to simultaneously open or close both of the nozzles, thus hydrostatically balancing the shaft. The edges of the raised ribs have cutting angles thereon for milling the opening of the nozzles during operation to produce an optimum gap between the rotary shutter and the nozzles. Only when the nozzles are closed is the flow directed into the outlet line to the consumer.

Abstract: A fluid pressure unit with a cylinder block is provided with radial bores of rectangular cross section. Pistons are disposed in the bores, each of the pistons being provided with a piston cap which is subjected periodically to pressure of a medium and with a roller resting against the piston cap. A cam is provided around the cylinder block, upon which the respective rollers rest. Each roller defines a variable throttle space with a first side wall of a respective one of the radial bores, which wall is vertical with respect to the rotational direction. The piston cap forms a sealing point with at least a second of two side walls.