A mechanism for implementing a delay in a directional control valve in the movement of a valve spool within a valve body from a first position of the spool to a second position of the spool.

A safety valve control system may include a remotely operable control assembly, a first transducer, a valve assembly, and a compressor assembly in communication with the control assembly. The control assembly is operable to actuate the pump and valve assemblies to supply fluid to actuate the safety valve into open and closed positions, in response to one or more signals received from the first transducer. A method of operation may include maintaining the safety valve in an open or closed position while sensing a physical property with the control system; communicating a signal corresponding to the sensed physical property to the control system; and automatically closing or opening the safety valve in response to a comparison of the sensed physical property to a pre-set condition.

A brake valve is insertable into a working line of a hydrostatic travel drive. The brake valve has a main stage with a first port connected to a variable displacement pump of the drive system and a second port connected to a motor of the drive system. The main stage has a slide piston positionable in a valve bore. In a freewheeling position, a connection is maximally open with minimal throttling between the two ports. In pressure-reducing positions, a regulable, throttled connection is open from the second to the first port to brake the motor. In pressure-limiting positions, a regulable, throttled connection is open from the first to the second port to begin to throttle a pressure medium flow from the variable displacement pump to a pressure protection mechanism. The positions lie on a center line of the main stage along which the slide piston is movable.

Electrohydraulic pilot control means (1) for a hydraulic device which can be a proportional directional valve, an adjusting pump or an adjusting motor, which pilot control means contains two proportionally acting pressure control valves (3) and is provided with a control block (2) which accommodates the hydraulic valve parts (4) in holes and to which the associated proportional magnets are flange-connected, wherein the proportional magnets have a common electrical plug connection (5) and wherein the two proportional magnets (3) are joined to form an assembly by being encapsulated with plastic, the said assembly being fastened to the control block (2) and, in this case, being precisely oriented relative to the valve components (4), which are accommodated in the control block, by means of positioning aids which act perpendicular to the movement direction of armatures.