Abstract: A hydraulic control device consists of a housing, a control slide valve displaceable in a bore of the housing, and a control ring. Axial displacement of the control slide valve makes it possible to connect together or to disconnect various connecting lines depending upon the position of the valve. Located in an annular chamber, formed between a section of the housing bore and the control slide valve is a control ring arranged coaxially with the valve and guided displaceably thereupon. Valve seats are spaced axially from each other both in the housing bore and on the control slide valve. The control ring comprises inner mating surfaces and outer mating surfaces cooperating with the valve seats. Provided between the two valve seats in the control slide valve is a flow channel running therein which is closed at one end depending upon the position of the control ring.

Abstract: An apparatus for pressing tubular parts, more particularly for pressing or forcing pipe-unions onto pipes, sleeves or hoses. The apparatus includes a plurality of spring loaded, radially adjustable jaws and an annular piston in operative communication with the jaws. The piston can move hydraulically towards the jaws and can be returned hydraulically to its neutral position. The effective area of the piston, by means of which it is returned to its neutral position, amounts to only a fraction of the piston-area which advances the piston. The end of the piston remote from the jaws engages in an annular hydraulic cylinder, the entire cross-section of the piston which is largest at this end, forming the effective piston-area which advances the piston.