A shuttle valve has a valve body including a first valve seat defining a first fluid inlet, a second valve seat defining a second fluid inlet, and a center portion that is connected to the valve seats, the center portion defining a fluid outlet and a bore. A moveable member is moveable within the bore between a first position against the first valve seat and a second position against the second valve seat to control the flow of fluid from either of the first or second inlet to the outlet. The moveable member may be configured to have a unitary construction formed of a single component, by which a unitary shell defines a substantially hollow interior. The moveable member has a hollow interior and a weep hole for equalizing pressure between the hollow interior and exterior of the moveable member.

An example valve includes: (i) a valve body defining a first longitudinal bore therein and including a first inlet, a second inlet, and an outlet; (ii) a cage disposed in the first longitudinal bore coaxial with the valve body, where the cage defines a second longitudinal bore therein; (iii) a pin mounted and extending longitudinally within the second longitudinal bore at an end of the cage adjacent to the first inlet; and (iv) a spool shiftably mounted within the second longitudinal bore and configured to move axially therein to shift between a first position and a second position. The spool includes a blind hole formed at an end thereof facing the pin and coaxial therewith, such that as the spool shifts from the second position to the first position, a portion of the pin is received within the blind hole of the spool.

A shuttle valve has a valve body including a first valve seat defining a first fluid inlet, a second valve seat defining a second fluid inlet, and a center portion that is connected to the valve seats, the center portion defining a fluid outlet and a bore. A moveable member is moveable within the bore between a first position against the first valve seat and a second position against the second valve seat to control the flow of fluid from either of the first or second inlet to the outlet. The moveable member may be configured to have a unitary construction formed of a single component, by which a unitary shell defines a substantially hollow interior. The moveable member has a hollow interior and a weep hole for equalizing pressure between the hollow interior and exterior of the moveable member.

A valve, in particular proportional pressure regulating valve, having a spring-loaded valve piston (10) which is guided in longitudinally displaceable fashion, in a manner actuated by an energizable actuating magnet (14), within a valve housing (12) and which, in a manner dependent on the displacement position thereof, produces or shuts off again a fluid-conducting connection between a pump port (P) and a working port (A) and between said working port (A) and a tank port (T) in the valve housing, wherein those face sides of the valve piston (10) which are situated opposite one another are permanently acted on by the pressure of the tank port (T), and wherein the valve piston (10) has a regulation surface (44) which is active in terms of pressure and which is connectable in fluid-conducting fashion to the working port (A) for the generation of the regulation pressure (P.sub.R), and having a ring-shaped chamber (42) in the valve housing (10), into which ring-shaped chamber the working port (A) opens in a radial or axial direction, characterized in that, on the valve piston (10), at the location of the transition between the ring-shaped chamber (42) and the opening-in point of the working port (A), the regulation surface (44) which is active in terms of pressure is designed such that, in the deenergized state of the actuating magnet (14), a maximum regulation pressure (P.sub.R) can be generated by virtue of a respective settled state between the force of a compression spring (30) of the spring-loaded valve piston (10) and the regulation pressure (P.sub.R) prevailing at the regulation surface (44) of the valve piston (10) taking effect.

An electromagnetic pressure regulation valve including an electromagnetic actuator that positions a piston that is received axially movable in a controller housing, wherein the piston is configured to open and/or close connections of the pressure control valve for flow through, wherein the piston includes a pin at a face surface that is oriented away from the electromagnetic actuator, wherein a relative movement is facilitated between the pin and the piston, wherein a pin face that is oriented away from the piston in the controller housing is arranged opposite to a stop, wherein the pressure control valve includes a hydraulic end position damping for damping a movement of the pin in a direction towards the stop.

An air-to-hydraulic fluid pressure amplifier comprising an air cylinder having an internal reciprocating air piston; a first hydraulic cylinder having a first valve fitting and a first internal hydraulic ram that is slidably positioned within the first hydraulic cylinder; a second hydraulic cylinder having a second valve fitting and a second internal hydraulic ram that is slidably positioned within the second hydraulic cylinder; a first flow control valve and a second flow control valve; a first plunger-operated pilot valve and a second plunger-operated pilot valve. Each of the first and second plunger-operated pilot valves comprises an inlet port, an outlet port, a plunger, a barrel, and a compression spring.

The invention relates to a valve, in particular a proportional pressure regulating valve, comprising a valve piston (12) which is longitudinally movable in a valve housing (10) for alternately releasing and connecting a user connection (A) to a pressure supply port (P) or a tank connection (T), which can be actuated by means of an actuating magnet (14) and which produces a dither signal during operation, characterized in that the valve piston (12) reaches a floating position within the valve housing (10) by means of a hydraulic lift limitation for the receipt of the dither signal.

A servovalve comprising: a fluid transfer valve assembly comprising a supply port and a control port; a moveable valve spool arranged to regulate flow of fluid from the supply port to the control port in response to a control signal; and a drive member configured to axially move the valve spool relative to the fluid transfer assembly in response to the control signal to regulate the fluid flow.

An actuating system comprising a hydraulic actuator provided with a cylindrical cavity containing a piston configured to slide within the cylindrical cavity and a rod. The piston separates the cylindrical cavity into a first actuating chamber and a second actuating chamber. A first servo valve comprises a sheath including a first slider configured to slide within a cavity of the sheath on the basis of command signals from a command system. The cavity of the sheath comprises a first command chamber and a second command chamber on either side of the first slider. The first actuating chamber is fluidically connected to the first command chamber, and the second actuating chamber is fluidically connected to the second command chamber.

A work machine to cut timber including a control system, a felling head, a hydraulic motor configured to adjust the position of the felling head, and a spool valve operatively connected to the hydraulic motor, the spool valve being configured to move the felling head responsively through operation of the hydraulic motor. A machine controller coupled to the operator controller and the spool valve executes stored program instructions to generate a first control signal responsive to an operator control signal provided by the operator controller, generate a second control signal as a function of the generated first control signal, adjust a position of the spool of the spool valve in response to a concurrent receipt of the first control signal and the second control signal by the first proportional control valve and the second proportional control valve to move the felling head through operation of the hydraulic motor.