Abstract: A proportional pressure control valve includes a valve housing (38) with at least three fluid connections (1, 2, 3). The valve can be connected to a hydraulic drive system with a pre-determinable consumer pressure. The valve can perform reliable valve switching functions even for low-viscous fluid media, and can reduce its susceptibility to disturbance variables. A valve piston (56) actively connected to a pilot seat (5) by an energy accumulator (62) can be controlled by a control device (40). The consumer pressure on a fluid connection (1) acts on the valve piston (56) such that, according to the consumer pressure and the actuating force of the control device (40), a fluid can flow between the two other fluid connections (2 and 3) in both directions inside the valve housing (38).

Abstract: A modular valve system includes at least one valve housing (40) having standard rate quantities on its opposite ends (38, 42), both on the inner peripheral side and on the outer peripheral side and inside the housing (52). Modular valve components, such as a valve piston (46), at least one energy accumulator (26), a pilot-controlled element, and at least one fluidic connection are mounted in the housing. The housing provides for fixing the valve embodied in the form of a screw-in cartridge for connection to other components.

Abstract: The invention relates to a piloted valve, particularly a piloted proportional throttle valve, having a valve piston (29) displaceably guided in the longitudinal direction in a valve housing (13) having a fluid inlet (2) and outlet (1), the front side (27) whereof can be pressurized against a main valve seat (25) by fluid pressure acting on the back side thereof, having a pilot valve device comprising an actuating member (7) displaceable in the longitudinal direction by means of an electrically actuatable magnet system (4), working together with a pilot valve seat (37) in a bore (17) of the valve piston (29) connecting the back side thereof to the fluid outlet (1) on the front side of the piston, in order to reduce the fluid pressure on the back side of the piston (29) for an opening motion when the pilot valve seat (33) is released, a flow baffle device (39) being disposed between the back side of the piston and the fluid inlet (2) of the housing (13) for building up the fluid pressure pressurizing the piston

Abstract: A valve, in particular, a proportional seat valve or gate valve, includes a valve housing (10) and at least three fluid connections (1, 2, 3) extending through the valve housing. A main piston (18) extends in the valve housing (10). A pilot piston (24) for executing a pilot control (26) may be controlled by a current-carrying magnetic device (28). During an open pilot control (26), fluid from one (2) of the connectors (1, 2), controlled by the main piston (18), reaches the connector (3), controlled by the pilot piston (24), by a cross-sectional narrowing (38) in the main piston (19). The pilot control (26) and, as a result of the corresponding pressure drop, the main piston (18) achieves a control position, controlling both fluid connections (1, 2) with regard to fluid amount.

Abstract: The invention relates to a valve, in particular, a proportional pressure relief valve, comprising an electrically controlled solenoid system (10) for the control of an operating part (12,12a) which cooperates with a valve element (26), running longitudinally inside a valve housing (24) which releases a fluid transport connection path, between a fluid inlet (32) and a fluid outlet (34), in the open position thereof, and which blocks the through path in the closed position thereof, whereby an energy store, preferably in the form of a compression spring (58) is arranged between the operating piece (12,12a) and valve element (26) in a free gap between the two, which tends to hold the valve element (26) in the direction of the closed position thereof and the operating piece (12a) is embodied as a type of guide piston (70) which has a longitudinal guide for the valve element (26).

Abstract: The invention relates to a valve, especially a proportional pressure control valve, comprising a valve housing (38) provided with at least three fluid connections (1, 2, 3). The valve can be connected to a hydraulic drive system with a pre-determinable minable consumer pressure. The aim of the invention is to create a valve that can perform reliable valve switching functions even for low-viscous fluid media, and to reduce the susceptibility to disturbance variables. To this end, a valve piston (56), which is actively connected to a pilot seat (58) by means of an energy accumulator (62), can be controlled by means of a control device (40), and the consumer pressure on a fluid connection (1) acts at least on the valve piston (56) in such a way that, according to the consumer pressure and the actuating force of the control device (40), a fluid can flow between the two other fluid connections (2 and 3) in both directions inside the valve housing (38).

Abstract: The invention relates to a valve, particularly a proportional pressure control valve for controlling fluid flows, comprising a valve housing (10), which has at least three fluid-conducting connections that, in particular, are provided in the form of a pump connection (P), a use connection (A) and of a tank (T) connection. In order to connect, as desired, the pump connection (T) to the use connection (A) and the use connection (A) to the tank connection (T), a control piston (18) can be guided in a longitudinally displaceable manner inside the valve housing (10), and this control piston is provided for establishing a fluid-conducting connection between at least one of the connections (P) and a pilot chamber (20) of a pilot valve (22) having a connecting channel (24).

Abstract: The invention relates to a valve, in particular, a proportional seat valve or gate valve, comprising a valve housing (10) and at least three fluid connections (1, 2, 3), extending through the valve housing a main piston (18), running in the valve housing (10) and a pilot piston (24), for executing a pilot control (26), which may be controlled by means of a current-carrying magnetic device (28), whereby during an open pilot control (26), fluid from one (2) of the both connectors (1, 2), controlled by the main piston (18), reaches the connector (3), controlled by the pilot piston (24), by means of a cross-sectional narrowing (38) in the main piston (19) and the pilot control (26) and hence, as a result of the corresponding pressure drop, the main piston (18) achieves a control position, controlling both fluid connections (1, 2) with regard to fluid amount.

Abstract: A pressure regulating valve, in particular a proportional pressure regulating valve, includes a valve body (1) with at least a pump connection (P), a use connection (A) and a tank connection (T). A piston (19), capable of being displaced by a controllable actuating device (29), is guided in the valve body (1). At the periphery of the piston, a recess (45) is formed and defines a peripheral annular gap (47) delimited by the control edges (49, 51) of the piston (19). In the piston (19), a passage (55) provides fluid communication between the front surface of the piston (19), subjected to the use connection (A) pressure, and the rear surface (35) of the piston (19), adjacent to a pressure chamber (37) located behind. The passage (55) of the piston (19) has, in the region proximate to the piston front surface, a restriction zone (57).

Abstract: A control device for a working device (12) connected to a hydraulic circuit (10), especially for a load fork (16) which can be raised and lowered with a working cylinder (14) in a fork-lift truck. A valve control unit moves into an adjustment position when the load fork (16) is lowered even when carrying a load (18). A predefinable maximum volume flow is maintained in the hydraulic circuit (10). By providing the valve control unit with a pressure regulator (26) limiting a pilot control pressure for the control valve (28), once a predefinable regulating pressure differential is reached in the hydraulic circuit, the control valve moves into a regulating position to maintain the maximum volume flow. The known flow control valve is replaced in the main flow by a pressure regulator (26) disposed in the pilot control circuit (40), and only needs to be dimensioned for low volume flows.

Abstract: The invention relates to a proportional pressure control valve comprising a valve housing (10) with at least three ports that conduct fluid, in particular in the form of a pump port (P), a utilisation port (A) and a tank port (T), a regulating piston (18) being configured to be displaced longitudinally in the valve housing (10) for the selective connection of the pump port (P) to the utilisation port (A), or of the utilisation port (A) to the tank port (T). Said piston is provided with a connection channel (24) for establishing a fluidic connection between the pump port (P) and a servo chamber (20) of a servo valve (22), the latter (22) being controlled by a magnetic system (28), in particular a proportional magnetic system. When the servo valve (22) is open, the fluidic path (58) that is partially guided through the valve housing (10) between the connection channel (24) and the tank port (T) is released, the latter having a simultaneous fluidic connection to the utilisation port (A).

Abstract: The invention relates to a pressure regulating valve, in particular a proportional pressure regulating valve. Said valve comprises a valve body (1) including at least a pump connection (P), a use connection (A) and a tank connection (T). A piston (19) capable of being displaced by a controllable actuating device (29), is guided in the valve body (1). At the periphery of said piston is formed a recess (45) which defines a peripheral annular gap (47) delimited by the ramps (49, 51) of the piston (19). In the piston (19) is provided a passage (55) for fluid communication between the front surface of the piston (19), subjected to the use connection (A) pressure, and the rear surface (35) of the piston (19), adjacent to a pressure chamber (37) located behind.

Abstract: A control device for hydraulically operated hoisting mechanisms used to raise and lower loads includes an electrically controllable throttle valve connected to a return line of the hoisting mechanism, and a pressure scale with at least one blocking position and one control position. The pressure scale operates in conjunction with an unblocking mechanism. When in its normal position, the pressure scale blocks the return line. The pressure scale assumes its control position in lowering of a load as a result of triggering of the unblocking mechanism. In the event of failure of the throttle valve, the pressure scale may be moved to its blocking position by the unblocking mechanism. In the event of failure of the pressure scale, the throttle valve assumes its blocking position. The load retention function is performed by two series-connected closed hydraulic actuators which can be electrically controlled individually.

Abstract: A valve, especially a pressure control valve, includes a housing (10) with a pump connection (P), an appliance connection (A) and a tank connection (T). A piston (16) controlled by a magnet armature (26) is guided inside the housing (10) of the valve. The vavle is provided with a hydraulic damping device (34) having a damping chamber (36) in fluid communication with appliance connection (A) through a throttle (38). The pump connection (P) or the tank connection (T) is selectively joined to the appliance connection (A) via a connecting line (40) according to the position of the piston (16). This valve improves upon known control valves so that the control valve remains stable in terms of behavior, especially with regard to permanent oscilliations.

Abstract: The invention relates to a control device for a working device (12) connected to a hydraulic circuit (10), especially for a load fork (16) which can be raised and lowered with a working cylinder (14) in a fork-lift truck, comprising a valve control unit which moves into an adjustment position when the load fork (16) is lowered even when carrying a load (18), a predefinable maximum volume flow being maintained in the hydraulic circuit (10). By providing the valve control unit with a pressure regulator (26) limiting a pilot control pressure for the control valve (28), once a predefinable regulating pressure differential is reached in the hydraulic circuit, said control valve moves into a regulating position in order to maintain the maximum volume flow and the known flow control valve is replaced in the main flow by a pressure regulator (26) disposed in the pilot control circuit (40) and which only needs to be dimensioned for low volume flows.

Abstract: A control device for hydraulically operated hoisting mechanisms used to raise and lower loads includes an electrically controllable throttle valve connected to a return line of the hoisting mechanism, and a pressure scale with at least one blocking position and one control position. The pressure scale operates in conjunction with an unblocking mechanism. When in its normal position, the pressure scale blocks the return line. The pressure scale assumes its control position in lowering of a load as a result of triggering of the unblocking mechanism. In the event of failure of the throttle valve, the pressure scale may be moved to its blocking position by the unblocking mechanism. In the event of failure of the pressure scale, the throttle valve assumes its blocking position. The load retention function is performed by two series-connected closed hydraulic actuators which can be electrically controlled individually.

Abstract: The invention relates to a pressure control valve (1) comprising a control piston (3) which is able to slide in a valve hole (4). Under the effect of an energy accumulator (5) said piston in one direction of displacement connects a pump connection (23) with a consumer connection (24) and in the other direction of displacement connects the consumer connection (24) with a tank connection (21) such that the pump connection (23) is closed off. The aim of the invention is to provide a pressure control valve which functions reliably and in a stable manner even in case of elevated control dynamics. To this end, independently of the direction of displacement of the control piston (3) a minimum volume flow present between the piston and the valve hole (4) dampens the displacement of the control piston (3).