Abstract: A safety valve assembly includes a pair of parallel-connected directional control valves controlled by solenoid-operated preliminary control valves; each directional control valve has a working piston and a valve member movable in a separate bore; the bores are interconnected by crossing passages and each passage is branched into a preliminary control channel communicating via a valve seat of the preliminary control valve with the working piston to admit sufficient amount of pressure medium against the working piston to switch the same over when the preliminary control valves are simultaneously operated.

Abstract: A safety valve assembly for pressurized medium-operated devices has a housing with a supply inlet, a consumer outlet, and a return outlet, two valves operating in parallel with one another, and each having a working piston and a valve member guided in chambers of the housing and operative for establishing and interrupting the communication between the inlet and outlets via two cross-passages wherein a pressure sensing element is provided having two opposite sides each communicating with a respective one of the cross-passages and displaceable in the event of malfunctions from its inoperative to its operative position so as to act in the latter position upon an actuating member arranged to turn off a consumer in response to the displacement of the pressure sensing element to its operative position.

Abstract: A safety valve assembly for pressurized medium-operated devices has two valves operating in parallel with one another and each having a working piston and a valve member. The assembly has a housing provided with a supply inlet, a consumer outlet and a discharge outlet. The valve members of the valves are guided in chambers provided in the housing and communicating with one another by passages which crosswise connect the chambers. The valve members in the chambers establish or interrupt communication between the inlet and outlets. When a malfunction occurs, at least one valve member blocks the cross passages so that the consumer outlet does not communicate with the inlet but, instead, is vented through the discharge outlet so that no residual pressure develops in the consumer outlet.

Abstract: The coupling and brake of a press receive pressurized fluid through a safety valve. The safety valve comprises two switching valves, so that if one of the switching valves fails and cannot close the other one can be closed. The safety valve is provided with a pressure-responsive switch which generates a shut-off signal commanding that the press be shut off, in response to a variety of malfunction situations, e.g., when the switching valves are closed but nevertheless a pressure build-up is occurring, or when the switching valves are open but the pressure being furnished to the coupling and brake does not reach or suddenly drops below the threshold levels to which the coupling and brake can respond.