Abstract: A force-balanced lifting valve for the control of a fluid, comprises a housing having paths for the fluid, an axially movable component in the form of a valve body provided on a shaft mounted so as to be axially movable in the housing, for the opening and closing a valve opening, and a sealing structure for sealing the axially movable component with respect to the housing. The valve body has associated therewith a force-balancing compensation area, which can be acted upon by pressure fluid by way of a subsidiary channel. The sealing structure comprises an elastic, axially effective sealing ring which sealingly engages the valve housing and the axially movable valve component, such that a radial portion of the ring rests axially and sealingly against at least one abutment shoulder on the axially movable valve component.

Abstract: A switching mechanism for preparing fluidic output signals of the kind comprising a first transformer acted upon by fluidic input signals which is connected in circuit in front of an electrical system which makes the converted signals available in the form of a control signal after expiration of a period presettable on said system, or of an event value. According to the invention, the electrical system comprises a combined switchable clock mechanism which is formed by a time function element (which is known per se) of the transistor or quartz type, and by a counter element (also known per se). The clock mechanism has post-connected to it a monostable multivibrator which has again connected to it a value means comprising a storage which may be activated by the transient control signal of the sweep stage for conversion of the electrical control signal of the clock mechanism into a fluidic output signal.

Abstract: A device of this nature incorporates at least one control piston displaceable within a casing, the casing having at least one venting nozzle authorizing the insertion of the piston into one of its possible operating positions, which nozzle may be shut off by means of an electromagnetically operated closing device for preparation of the outward displacement of the piston out of this operating position. To accomplish that such devices may manage with a substantially reduced electrical battery power for their electromagnetic closing device, a permanent magnet is provided which co-operates with a ferromagnetic member of the closing device, in such manner that the closing device continues to be held in its closing position while the control piston is being reversed, although the supply of electrical power to the closing device had already been turned off.