For the purpose of providing a valve arrangement for controlling pneumatic drives with protection against a sudden automatic change in the initial switching position without an input signal in the event of a fault in a resetting device of a pilot stage and, for this situation, effective fault identification by purely pneumatic means, said valve arrangement comprises a first and a second working connection (1; 2), which can be connected to a drive, and a first and a second electropneumatically pilot-controlled directional valve, in which valve arrangement one or both directional valves is or are arranged upstream of the working connections (1; 2) for the purpose of influencing and venting said working connections, wherein the pilot stages of both directional valves are of automatically resetting design and the second directional valve is designed for alternately assuming an inoperative position and a switching position and the pilot stage of the first directional valve has an external control connection (8; 8′) which can be influenced by means of the second directional valve in its switching position and can be vented by means of said second directional valve in its inoperative position, wherein the second directional valve has, as a resetting device for the main stage (14), an air spring (19) which can be influenced and can be vented externally by means of the first directional valve, and a change in state between influencing or venting of the air spring (19) after the first directional valve assumes a switching position takes place only depending on the change in the switching state of the first directional valve, and a change in state between influencing or venting at one working connection (1; 2) after previous influencing or venting which took place with the second directional valve assuming the switching position takes place only depending on the second directional valve assuming the inoperative position.

A redundant valve manifold system includes at least two automatic valves coupled to one another and at least two automatic isolation valves each corresponding to one of the at least two automatic valves. Each of at least two automatic isolation valves is operatively coupled to one of the at least two automatic valves and isolates the one of the at least two automatic valves when the one of the at least two automatic valves is removed from the system to deliver media to an outlet.

A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a second solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. The system includes a pressure-switching valve operatively coupled to the first and second solenoids. The system includes an actuator operatively coupled to the pressure outlet of the second solenoid.

A solenoid driven actuator system includes a first solenoid having at least one pressure input and a pressure outlet downstream from the at least one pressure input. A second solenoid has at least one pressure input and a pressure outlet downstream from the at least one pressure input. A transfer solenoid operatively coupled to the first and second solenoids. An actuator valve operatively coupled to a pressure outlet of the transfer solenoid.

A hydraulic system includes: a solenoid valve that includes a valve spool configured to slide within a housing, and moves the valve spool to a position corresponding to an operation command input to the solenoid valve; and a control device that outputs the operation command to the solenoid valve. When a predetermined condition is satisfied, the control device outputs a continuously or intermittently changing operation command to the solenoid valve to reciprocate the valve spool from a full open position or a full closed position.

Valve arrangement for influencing a fluid flow for a fluid consumer, having a first valve group with which a first actuator is associated, having a second valve group with which a second actuator is associated, the first valve group and second valve group being associated in a first functional position as a parallel circuit with a first fluid line in a first functional position and are associated with a second fluid line in a second functional position as a series circuit, the first valve group or second valve group being designed for actuating the respective other actuator in the first functional position and being designed for switching off the respective other actuator in the second functional position.

An actuator system for an aircraft includes an actuator, and a control valve system operatively connected to the actuator. The control valve system includes a first direct drive valve (DDV) mechanically connected to a second DDV. A backup valve system is operatively connected to the actuator. The backup valve system includes one of an electro-hydraulic servovalve (EHSV) and a DDV.

The invention relates to a hydraulic control system of a hoist drive of a lifting frame of an industrial truck, wherein the control system has a directional control valve device which is connected with a delivery line of a hydraulic pump, a reservoir line leading to a reservoir and a connecting line leading to the hoist drive, wherein the directional control valve device is configured to control the lifting operation and the lowering operation of the hoist drive. The control system has a pressure protection valve that is associated with the connecting line, wherein the pressure protection valve is configured to limit a peak pressure introduced into the lifting frame in the event of a fault scenario of the directional control valve device.

An actuator system can include a first actuator, a second actuator, a first actuator control device configured to control the first actuator, a second actuator control device configured to control the second actuator, a shared redundant actuator control device, and at least one transfer device operatively connected to the first, second, and shared redundant actuator control devices. The at least one transfer device can be configured to be operated to select between a first control mode where the first actuator control device is operatively connected to the first actuator to control the first actuator and the second actuator control device is operatively connected to the second actuator to control the second actuator, a second control mode where the shared redundant actuator control device is operatively connected to the first actuator to control the first actuator and the second actuator control device is operatively connected to the second actuator to control the second actuator, and a third control mode where the first actuator control device is operatively connected to the first actuator to control the first actuator and the shared redundant actuator control device is operatively connected to the second actuator to control the second actuator.

A redundant valve manifold system includes at least two automatic valves coupled to one another and at least two automatic isolation valves each corresponding to one of the at least two automatic valves. Each of at least two automatic isolation valves is operatively coupled to one of the at least two automatic valves and isolates the one of the at least two automatic valves when the one of the at least two automatic valves is removed from the system to deliver media to an outlet.