Abstract: A compensating valve arrangement is connected between a throttling direction control valve or proportioning valve which controls fluid flow from a pressure source to a load. The compensating valve is provided with a pressure reducing valve, check valves and throttling points between the pressure supply and the control piston of the compensating valve to compensate for surges, prevent sudden driving of the load and prevent leakage.

Abstract: A control-circuit throttle valve assembly coupled to and regulating a hoisting unit correcting element or final control element of a tractor via a mechanical coupling including a throttle housing, a flow restrictor throttling body shiftably mounted in the throttle housing, the throttling body having a guiding edge portion, a control conduit with a circular cross-section communicating with the throttle housing, the control conduit including a pass-through area, and a run-off conduit communicating with the throttle housing, the guiding edge portion at least partially closing off communication between the control circuit and the throttle housing through the pass-through area upon shifting of the throttling body within the throttle housing such that the pass-through area is throttled as a linear function during operation of the hoisting unit.

Abstract: A control circuit throttling valve provided as a controlled dimension receiver in a hydraulic circuit for the control of a final control element, particularly for the control of a lifting unit of a tractor. The valve performs a receiver function under control of a mechanical coupling coupled to a moving part of the final control element which changes the valve throttling section and is adjustable and includes a casing having a control connection and a discharge connection and a movable throttling body provided in the casing in relation to the control connection and the discharge connection such that upon linear or rotational movement of the body it is possible to independently derive an adjusting function and a receiving function.

Abstract: Disclosed is a support unit for the cab of a utilitarian vehicle having a separate cab and chassis. The support unit includes a hydraulic piston and cylinder, including a compression spring, connected between the cab and the chassis. Fixed to the hydraulic support cylinder unit is a directional control valve which selectively directs and drains pressurized hydraulic fluid to or from the hydraulic support cylinder unit. The directional control valve is journalled to a lever pivoted to the cab. Also journalled to the lever are an elastically centered rod and an absorber element having an inelastically adjustable length. Dynamic fluctuations of the distance between the chassis and cab are opposed by the hydraulic support cylinder unit as actuated by the directional control valve. Static fluctuations in the distance between the chassis and the cab are accommodated by the hydraulic support cylinder unit together with the absorber element.

Abstract: A hydraulic internal gear machine includes a positive displacement unit for working liquid constituted by a rotary outer gear and an inner gear surrounding the outer gear and being in mesh therewith at one point to define a plurality of increasing liquid displacement chambers. The chambers are laterally bounded by a rotary disc which cooperates with a stationary control plate. The disc and the control plates are formed respectively with flow control openings for admitting pressure liquid into a half of the chambers and for discharging the liquid from the other half of the number of chambers. To compensate for the tilting moment acting on the rotary disc, the interface between the rotary disc and the control chamber is provided with arcuate recessed sections communicating with the openings in the rotary disc to apply pressurized liquid in the displacement chambers against both sides of the rotary disc.

Abstract: The invention provides a device for regulating the tractive force in the lower linkage system of a tractor lifting gear which serves, for example, to hold a plough. The lower linkages on which the tractive resistance, acting on the plough, is exerted transmit the tractive force to a bending bar, the bending of which is recorded as a measurement of the tractive force. In accordance with the invention the bending bar is rigidly coupled to a bearing frame which is rigidly mounted on the tractor and which absorbs the force acting on the lower linkages while the bending bar is subjected to bending strain. This means that the lower linkages do not exert a force directly on the bending bar, and the bending bar can therefore be supported free from play.

Abstract: In a hydrostatic gear machine of the type having an internally toothed outer gear and an externally toothed inner gear wherein the gears have different numbers of teeth, the gears being meshed with the outer gear surrounding gear, particularly advantageous relationships between the numbers of teeth and the shapes of the tooth flanks are provided to permit economic manufacture of the machine for use as a motor or pump.

Abstract: An apparatus for controlling a single action piston and cylinder having means biasing the piston toward a retracted position within the cylinder and having a non-return valve openable toward the cylinder connecting the cylinder with a fluid pressure source comprises a control valve and a proportional valve. The control valve has an inlet in fluid communication with a supply tank, an outlet in fluid communication with a supply tank, a control port in fluid communication with the fluid pressure source, and a control element movable between open and closed positions for controlling flow of fluid pressure from the inlet to the outlet. The control element is spring biased toward the open position and forced toward the closed position by pressure entering through the control port. The proportional valve regulates the pressure entering through the control port.

Abstract: The pressure fluid regulating valve has a central blind bore provided with axially spaced inlet and outlet openings, a sliding spool movable in the blind bore and defining two piston-like areas at its ends and an intermediate recessed portion having inclined walls and a central flange of a trapezoidal contour; a central bore in the spool interconnects via a throttling passage the end faces of the piston-like areas and communicates also with the recessed portion; the recessed area in the rest position of the spool interconnects the inlet and outlet openings and the inclination of respective sloping walls of the recessed portion and of the flange is selected so as to ensure a substantially uniform flow through the passage in any axial position of the spool.

Abstract: The hydraulic axial piston engine has a rotary shaft and a stationary control plate symmetrically connected to a two-piece housing supporting for rotation the shaft. Two stationary lifting cams are arranged opposite each other at the end walls of the housing around the shaft; two rotary cylinder blocks are supported for joint rotation on the shaft and each adjoins a face of the control plate; the end walls of the cylinder blocks facing the cams are provided with a plurality of uniformly distributed and axially directed blind bores for accommodating working pistons. The end walls in each blind bore has a through passage for working fluid and the control plate in the range of the passages has a plurality of uniformly distributed control openings connected alternately to two annular distributing channels formed in the plate, one of the channels being connected to an intake port and the other channel to a discharge port for the working fluid.

Abstract: The hydraulic control- and/or measuring device has a housing and a socket-shaped control slider movable in a cylindrical bore in the housing between an open position in which it passes a pressure fluid from an inlet opening to an outlet opening; a stationary jet intercepting member projects into the blind bore of the slider and has a deflection disk located outside the range of the inlet opening to intercept fluid energy at the beginning of the opening phase.

Abstract: A radial piston pump has a housing bounding a suction chamber therein and provided with a plurality of pressure ports spaced from one another in circumferential direction of this housing, and with at least one suction port. A plurality of valve units spaced from one another in the circumferential direction of this housing are provided, each of which includes a pressure valve element located in a respective one of the pressure ports and a sleeve member mounted in the same pressure port radially outwardly of the pressure valve element so as to form, together with the latter, a pressure chamber inwardly of and communicating with the pressure port. A plurality of circumferentially extending channels are formed in this housing and intersect the respective pressure chambers.

Abstract: An electrode-position control for arc furnaces includes a hydraulic cylinder-and-piston unit 1 having a cylinder chamber 43 and a piston 1 connectable with an electrode 4 to be moved; a control valve 8; a first pressure conduit 14, 15 which connects the control valve 8 with a source of pressure fluid, and a working conduit 17, 18 which connects the valve 8 with the chamber 43; a pre-selectable two-way valve 5, 6 in each of the conduits 14, 15; 17, 18 a second pressure conduit 34, 33, 17, 42 connecting the chamber 43 directly with the source; and a pre-selectable two-way valve 7 arranged in the second pressure conduit 34, 33, 17, 42 in parallel to the control valve 8, the valve 7 being closed when the valves 5, 6 are open, and vice versa.

Abstract: A radial piston pump comprises a housing bounding a suction chamber therein and at least one valve piston unit mounted in the housing. The valve piston unit includes a pressure valve defining a pressure chamber, a movable piston having an axial passage operatively communicating the suction chamber with the pressure chamber, and a suction valve located in the axial passage of the piston. The suction valve is operative for opening and closing the axial passage of the piston so as to establish and interrupt the above communication, respectively. The piston performs a suction stroke and a working stroke, and a valve member of the suction valve is open during the suction stroke of the piston. The valve member has such a mass that it is opened by an accelerative force produced during the above suction stroke of the piston. The piston is moved by an eccentric mounted on a rotatable shaft, which eccentric has a circumferential groove operatively communicating the suction chamber with the axial passage of the piston.

Abstract: A gerotor machine has a housing and a displacement unit in the housing. The displacement unit includes an inner gear wheel rotatable about an axis, and an outer gear wheel which has an axis circularly displaceable about the axis of rotation of the inner gear wheel. The gear wheels bound a plurality of displacement chambers therebetween. A plurality of recesses are formed between the teeth of one of the gear wheels, and each of the recesses has two circumferentially spaced control edges at one axial end of the one gear. The housing is provided with a plurality of control openings which are located relative to the axis of the one gear at a radial distance corresponding to that of the recesses. The control edges of the recesses of the one gear cooperate with the control openings of the housing and are operative for communicating the control openings with the chambers of the displacement unit.

Abstract: The radial pump preferably for use in connection with a hydraulic clamping device includes a plurality of pumping elements enclosed in a housing and cooperating with a corresponding pluraity of discharge valves. A multiway control valve controls the delivery of pressure fluid to a load port in such a manner that during the actuation of the load the outlet of all discharge valves are united to deliver the entire flow of pressure fluid into the load port, whereas when the load is maintained under a constant pressure, only one pumping element delivers discharged fluid via a single discharge valve into the load port and the remaining pumping elements deliver their output into the reservoir.

Abstract: A hydraulic control arrangement with a feedback device for positioning an implement comprises a positioner including a fluid operated cylinder and piston unit, the piston of which is connected by a plurality of linkage elements to the implement. A first pump delivers through a pressure line fluid under pressure into the cylinder. A two-port three-position valve is interposed in the pressure line movable from a neutral position in which the fluid fed by the first pump is directed to a reservoir, to two operating positions to opposite sides of the neutral position, and in which one of the operating positions fluid fed by the first pump passes into the cylinder and in the other of the operating positions fluid from the cylinder can flow to the reservoir. A pair of pilot chambers are arranged at opposite ends of the valve for moving the latter from the neutral to either of the working positions. A second pump provides fluid under pressure for operating the valve.

Abstract: A multi-position flow control valve comprises a control piston movable in a boring in two opposite directions. At each end of the boring a pressure chamber is provided accommodating a pressure spring supported on a spring collar that at its end facing the boring has a conical recess. Each recess accommodates a conical projection of a supporting rod that is slidably guided in a blind end bore provided in the control piston. A spring is arranged in the blind end to urge the supporting rod into engagement with the recess in the spring collar. If a pressure fluid is introduced into one pressure chamber, it displaces the piston and compresses the biasing spring in the other pressure chamber whereby the spring biased supporting rods remain in engagement with the recesses in the spring collars.

Abstract: A flow meter comprises a housing defining a fluid inlet passage and a fluid outlet passage; a piston defining a jacket surface and a base surface is arranged in the housing for reciprocating movement between the two passages; a biasing spring urges the piston into a zero flow position in which the piston interrupts the communication between the two passages; the base surface of the piston faces the inlet passage so that the fluid flow displaces the piston into a flow position; flow distributing means in the form of a partition arranged in the outlet passage has a plurality of slots shaped for adjusting the flow rate between the two passages according to the variation of the spring bias of the moving piston; and an electrical position detector coupled to the piston to generate an electrical signal proportional to the displacement of the piston.

Abstract: A rotary fluid displacing apparatus operable as pump or motor comprises a housing in which a fluid displacing unit is arranged comprising an annular stator having a plurality of radially inwardly extending teeth and a rotor within the stator and having radially outwardly extending teeth numbering one tooth less than those of the stator, meshing with the teeth of the latter, and forming between the stator and the rotor spaces increasing and decreasing during rotation of the rotor. Flow of fluid into and out of these spaces is controlled by a stationary control plate and a rotary control disc, both of which are formed with a central opening through which a universal-joint shaft extends which, at one end is tiltably connected to a machine shaft mounted in the housing for rotation about a fixed axis.