Abstract: A valve control arrangement for internal combustion engines with reciprocating pistons, comprises a housing having a housing opening, a valve piston axially displaceable in the housing opening, a valve closing spring, a valve plunger on which the valve piston acts against the valve closing spring, a cam piston axially displaceable in the housing opening, a valve control cam, a pressing spring which presses the cam piston against the valve control cam, a working chamber formed between the valve piston and the cam piston and arranged to be filled with pressure medium which transmits a lifting movement of the cam piston to the valve piston, the pressing spring which acts on the cam piston being arranged outside of the working chamber and supported at the side of the housing.

Abstract: In a vane type compressor, in which a plurality of radial vanes are supported on a compressor shaft and extended through a rotary piston, each vane is formed of two wall portions spaced from each other and two ring portions receiving bearings for supporting the vanes on the shaft. The wall portions and the ring portions of each vane are formed as a one-piece element which may be produced by stamping-out and bending a sheet metal. A supporting structure of kernels of aluminum disposed in a honeycomb manner is inserted between two wall portions of each vane.

Abstract: In a vane type compressor including a plurality of radial vanes extending from a compressor shaft through the slots in a rotary piston elastic flexible tubes are inserted in the slots and interconnected between the respective vanes and the rotary piston, which serve as sealing members on the vanes. Each flexible tube has an elongated bead engaged in a groove formed either in the vane or in the rotary piston.

Abstract: A sliding vane compressor for use in refrigeration systems includes a rotatable hollow shaft, a cylindrical compressor rotor which surrounds the shaft, end covers enclosing the compressor rotor and a pair of vanes disposed within the rotor to compress a working medium entering the rotor. The compressor rotor and end covers have end faces in a contact area therebetween. At at least one of end faces of either rotor or end cover, a number of spirally-shaped grooves are formed curved in the direction of rotation of the rotor shaft. These grooves extend from the periphery of the respective end face toward the center thereof but short of said center to produce a flow preventing leakage of the working medium between the low pressure region and the high pressure region in the compressor.

Abstract: A positive displacement machine has a housing bounding an elongated interior compartment, a flat displaceable part-circular element in said compartment subdividing the latter into a pressure chamber and a suction chamber and having a recess in a periphery thereof bounded by two edges which are spaced circumferentially of the periphery, and drive elements for imparting to the displaceable element a translatory displacement and for superposing on the translatory displacement an angular movement such that during displacement of the element between two opposite dead center positions, the pressure and suction chambers are temporarily placed in communication by the recess of the displaceable element so as to permit displacement of a fluid from one to the other chamber. The displaceable element has a periphery exceeding over more than 180.degree. of arc and a diameter corresponding to the width of the interior compartment of the housing in a direction transverse to the elongation of the compartment.

Abstract: A hydraulic steering arrangement for the wheels of a motor operated vehicle comprises a first manually controlled servo steering mechanism operatively connected to the wheels of the vehicle, a second automatically controlled steering mechanism also operatively connected to the wheels for steering the vehicle along a predetermined path and means for selectively connecting either of the steering mechanisms to a source of pressure fluid.