Abstract: A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.

Abstract: A hydrodynamic machine for producing a braking torque, the hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and a hydraulic system including an open loop and closed loop control unit, a working medium accumulator, a line system, a pump operable to produce a volume flow circulation of a working medium through the line system and the toroidal working chamber, a heat exchanger, and a pressure control valve operable to control or adjust the baking performance or the braking torque.

Abstract: A hydrodynamic machine for producing a braking torque, the hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and a hydraulic system including an open loop and closed loop control unit, a working medium accumulator, a line system, a pump operable to produce a volume flow circulation of a working medium through the line system and the toroidal working chamber, a heat exchanger, and a pressure control valve operable to control or adjust the baking performance or the braking torque.

Abstract: A hydrodynamic machine comprising: a toroidal working chamber including a first bladed wheel and a second bladed wheel arranged concentrically with the first bladed wheel; and an electrohydraulic system including an open loop unit and a and closed loop control unit, a working medium accumulator, a pump operable to pump a working medium from the working medium accumulator into the toroidal working chamber, a heat exchanger, a valve operable to switch between a first position, the first position being a non-braking position, and a second position, the second position being a braking position, and a line system operable to allow the pump to pump the working medium in both the first position and the second position into the working chamber.

Abstract: A height adjustment device of a vehicle seat comprises a control valve means for governing the degree of filling of a compressed air actuator. Following an alteration in the weight to be carried by the compressed air actuator there is a relative switching over movement between a component bearing a control cam slide and a component bearing an actuating member entailing the switch over of the control valve means. The relative switching over movement is a linear movement, the two components bearing the slide and the actuating member being guided for relative sliding linear motion in the direction of the switch over movement. Furthermore a vehicle seat having such a height adjustment device is provided.

Abstract: A height adjustment device of a vehicle seat comprises a control valve means for governing the degree of filling of a compressed air actuator. Following an alteration in the weight to be carried by the compressed air actuator there is a relative switching over movement between a component bearing a control cam slide and a component bearing an actuating member entailing the switch over of the control valve means. The relative switching over movement is a linear movement, the two components bearing the slide and the actuating member being guided for relative sliding linear motion in the direction of the switch over movement. Furthermore a vehicle seat having such a height adjustment device is provided.

Abstract: A drive unit includes a hydrodynamic retarder having a rotor paddle wheel, a stator paddle wheel, and a housing surrounding the rotor and stator wheels. The unit includes a coolant cycle system for an internal combustion engine, the coolant for this coolant cycle also being a working medium of the retarder. The drive unit further includes a working medium container for the coolant. A first pipe connects a hydrodynamic center of the retarder to a valve. A second, leakage pipe is disposed between a working medium outlet of the retarder and the valve. A third pipe is disposed between the valve and the working medium container. The valve is designed such that in a first position, a conducting connection is established between the working medium container and the leakage pipe to provide for a pumping operation of the retarder. When the valve is in a second position, a conducting connection is established between the working medium container and the first pipe for a braking operation of the retarder.

Abstract: A drive unit includes a hydrodynamic retarder having a rotor paddle wheel, a stator paddle wheel, and a housing surrounding the rotor and stator wheels. The unit has a coolant cycle system, through which a coolant flows, the coolant also being a working medium of the retarder. The drive unit further includes a working medium container for the coolant and a pipe having a valve. The pipe is disposed between the retarder and the working medium container. The unit also has a coolant feed line to the retarder.

Abstract: A directional control valve for compressed air with an inlet port, at least one consumer port and at least one vent port includes a housing accommodating a control piston for controlling the connection between the inlet port, the consumer port and the vent port, and a one-way restrictor arrangement. The one-way restrictor arrangement is fitted directly within the housing between the vent port and the consumer port, transversely to the longitudinal axis of the control piston. In this manner, a flow of compressed air to the consumer is prevented upon occurrence of a dynamic pressure.

Abstract: A directional control valve includes a housing with a pressure inlet port, two working ports and a vent port with one working port directly connected to the vent port and the other working port communicating with the vent port via a control piston. The control piston includes a sliding valve in the area of one working port and a seat valve in the area of the other working port. A throttle bush rotatably arranged in the housing and a throttle screw rotatable relative to the throttle bush cooperate with the control valve to modify and throttle separately and independently from each other the cross sectional ventilating areas for the working ports.

Abstract: A safety valve assembly for regulating the flow of a fluid under pressure to a fluid operated system e.g. a double acting cylinder element includes a housing with an inlet port, outlet ports and working ports and accommodating a pair of parallel valve spindles which are controllable by respective pilot valves so as to be shiftable between two valve positions. Each valve spindle is provided with a working piston, valve piston and a control piston which cooperates with a respective valve seat as defined by the housing. The control pistons of the valve spindles are successively disposed in a passageway extending between one of the working ports and one of the outlet ports.

Abstract: A two hand safety control mechanism for a consumer actuated by pressure medium includes a safety valve blocking the supply of pressure medium during a faulty switching and venting the consumer. For maintaining a working position of the consumer, a plurality of control valves are provided which are dynamically self-regulating. By actuating a further control valve, the automatic retention can be cancelled in order to allow the consumer to return in its idle position.

Abstract: The invention relates to a pressure regulating valve for pneumatic and hydraulic pressure media wherein a higher primary pressure is regulated to a desired lower secondary pressure. The valve comprises a primary connection, a secondary connection and a relief connection, there being a switch valve between the primary connection and the secondary connection, a relief valve between the secondary connection and the relief connection, and a control connection for controlling the operation of the valve in response to an external controlled quantity. The controlled quantity may be the secondary pressure output of the valve, or may be another pressure or a mechanical displacement of a larger system.

Abstract: A pressure regulating valve for pneumatic or hydraulic pressure fluids, by means of which a higher primary pressure is regulated to a lower secondary pressure, comprises a housing provided with a primary fluid connection, a secondary fluid connection and a fluid relief connection, a first valve for controlling flow of fluid between the primary fluid connection and the secondary fluid connection and a second valve for controlling flow of fluid between the secondary fluid connection and the fluid relief connection, in which both valves are constructed as seat valves.

Abstract: An impulse valve has a housing provided with a working chamber and a main piston movable in the working chamber; two preliminary control valves are electromagnetically operated for a short period to switch over the main piston into a selected switching position which is retained even if the preliminary control valve is deenergized. To reduce volume of the valve and to reduce manufacturing cost, a flexible diaphragm is arranged between the preliminary control valves and the main control valve and cooperates with two opposite valve seats in such a manner as to establish connection between an inlet port to the working chamber and alternatively to pressure-relieve the working chamber.

Abstract: A sealing arrangement, particularly for sealing a valve piston relative to a valve housing, has a plurality of sealing rings arranged to be located between a valve piston and a valve housing, and axially spaced from each other, and a plurality of supporting rings located axially adjacent to each other and arranged to support and hold the sealing rings, wherein the supporting rings are connected with the sealing rings in interengaging manner so as to form together with the latter an integral unit which can be mounted and dismounted as a whole.

Abstract: A safety valve assembly includes a pair of parallel-connected directional control valves controlled by solenoid-operated preliminary control valves; each directional control valve has a working piston and a valve member movable in a separate bore; the bores are interconnected by crossing passages and each passage is branched into a preliminary control channel communicating via a valve seat of the preliminary control valve with the working piston to admit sufficient amount of pressure medium against the working piston to switch the same over when the preliminary control valves are simultaneously operated.

Abstract: A safety valve assembly for pressurized medium-operated devices has a housing with a supply inlet, a consumer outlet, and a return outlet, two valves operating in parallel with one another, and each having a working piston and a valve member guided in chambers of the housing and operative for establishing and interrupting the communication between the inlet and outlets via two cross-passages wherein a pressure sensing element is provided having two opposite sides each communicating with a respective one of the cross-passages and displaceable in the event of malfunctions from its inoperative to its operative position so as to act in the latter position upon an actuating member arranged to turn off a consumer in response to the displacement of the pressure sensing element to its operative position.

Abstract: A safety valve assembly for pressurized medium-operated devices has two valves operating in parallel with one another and each having a working piston and a valve member. The assembly has a housing provided with a supply inlet, a consumer outlet and a discharge outlet. The valve members of the valves are guided in chambers provided in the housing and communicating with one another by passages which crosswise connect the chambers. The valve members in the chambers establish or interrupt communication between the inlet and outlets. When a malfunction occurs, at least one valve member blocks the cross passages so that the consumer outlet does not communicate with the inlet but, instead, is vented through the discharge outlet so that no residual pressure develops in the consumer outlet.

Abstract: The direction control valve comprises a housing having a stepped central boring for accommodating a sliding control piston having a section of larger diameter and a section of smaller diameter. The housing defines two load ports each communicating with an assigned boring section through an annular gap. One load port is directly connectable through its annular gap with a pressure releasing or venting port and the other load port is connectable to the same venting port through a central passage in the piston.