An example valve includes: a housing having a first longitudinal cavity therein; a sleeve disposed, at least partially, in the first longitudinal cavity, where the sleeve has a second longitudinal cavity therein, and includes a first seat formed as a protrusion from an interior peripheral surface of the sleeve; a poppet mounted within the second longitudinal cavity and configured to move axially therein; and a bushing mounted, at least partially, in the second longitudinal cavity, such that the bushing is floating and is allowed to move axially in the second longitudinal cavity, where the bushing is hollow and defines a first port at a distal end of the bushing and defines a second seat at a proximal end of the bushing, and where the sleeve defines a second port and a third port disposed on an exterior peripheral surface of the sleeve.

A fluid delivery device includes a tube coupled to an axial manipulator. The axial manipulator includes an elongate member arranged to move axially in a housing. The tube is in fluid communication with a fluid diverter which is arranged to move axially in the housing upon axial movement of the elongate member. Seals are provided to prevent fluid from leaking out of the housing. A fluid port is in fluid communication with the tube via the fluid diverter, such that fluid can flow in and out of the tube via the fluid port and the fluid diverter.

Apparatus to bias spool valves using supply pressure are disclosed. An example apparatus includes a sleeve of a spool valve, and a spool within the sleeve to control a flow of fluid at a supply pressure through the spool valve as the spool is moved relative to the sleeve in response to a variable input force. A biasing force is to bias the spool opposite the variable input force. The biasing force is to be generated from a biasing pressure of the fluid within a chamber adjacent a biasing end of the spool. The biasing pressure is to be based on the fluid at the supply pressure provided directly to the chamber from a supply of the fluid independent of the flow of the fluid through the spool valve.

A valve has a valve housing which is connected to an electronics unit. The electronics unit has an electronics unit housing which has an aperture in order to establish electrical contacting with an actuator of the valve. A portion of the actuator may protrude into the aperture. Here, play is provided between the aperture and the portion of the actuator.

A proportional valve is provided having a pilot control valve that can be controlled by means of a control signal and having a booster valve that can be actuated by means of the pilot control valve. The proportional valve has a compressed-air connection for connecting a compressed-air supply, a working connection, and an air-removal connection. The booster valve has three valve elements, which are arranged one after the other and can each be moved in an axial direction against a spring force.

A main spool (24) has a throttle passage (30) that, when the main spool (24) moves to an axial other side against a first return spring (27) in a main spool insertion hole (13), communicates a pilot pressure chamber (25) with a first tank port (15) and limits a flow amount of hydraulic oil to be discharged to the first tank port (15) from the pilot pressure chamber (25). When the main spool (24) moves to the axial other side along the main spool insertion hole (13), the throttle passage (30) communicates the pilot pressure chamber (25) with the first tank port (15) before a state where a first pump port (17) is communicated with an output port (16) and a state where the output port (16) is blocked from the first tank port (15).

A hydraulic suspension system includes a suspension cylinder, a pump, and a control valve therebetween. The control valve includes a spool reciprocally movable between a pump flow position and a tank flow position in which a control port of the control valve is in communication with a pump and a tank, respectively. A piloted logic element in fluid communication with and interposed between the control valve and the suspension cylinder is selectively movable between a through-flow position in which fluid can flow in either direction between a chamber of the suspension cylinder and the control port of the control valve and a blocked position in which fluid is prevented from flowing in or out of the chamber of the suspension cylinder. The logic element is biased to the blocking position, moving to the through-flow position when subjected to a crack pressure delivered from the control port of the control valve.

A fluid delivery device includes a tube coupled to an axial manipulator. The axial manipulator includes an elongate member arranged to move axially in a housing. The tube is in fluid communication with a fluid diverter which is arranged to move axially in the housing upon axial movement of the elongate member. Seals are provided to prevent fluid from leaking out of the housing. A fluid port is in fluid communication with the tube via the fluid diverter, such that fluid can flow in and out of the tube via the fluid port and the fluid diverter.

In an electromagnetic proportional control valve system, left and right position control apparatuses 20 and 30 are disposed on the both ends of a main spool in a three position proportional control valve 10 and perform stroke control for the main spool. The left and right position control apparatus respectively comprise position feedback springs 25 and 35, pilot control valves 21 and 31, and proportional solenoids 27 and 37. The pilot spool is moved, for operative control, in response to a compression force of a position feedback spring and an electromagnetic force of the proportional solenoid. In addition, the output pressure is applied to both ends of the pilot spool so that control is performed to generate output pressure with a negative characteristic against the electromagnetic force of the proportional solenoids.

The present application relates to a switching valve, a switching hydraulic system, and a crane, in which the switching valve having an oil inlet and an oil outlet comprises at least two pairs of valve oil ports, a pair of cartridge valves provided between each pair of valve oil ports, and the oil inlet and the oil outlet are controlled such that the oil inlet and the oil outlet are capable of shifting between communications with the at least two pairs of valve oil ports. The switching valve switches on and off communication between the oil inlet and the oil outlet and the at least two pairs of valve oil ports by controlling opening or closing of the cartridge valves.