rod end of the cylinder housing 50 and from the head end of the cylinder housing 50 into the reservoir 34 in a neutral position u201c b u201d a flow of pressurized fluid is prevented in every direction and the pressurized fluid conducted by the pump 36 is returned to the reservoir 34 in an extension position u201c c u201d pressurized fluid is conducted from the pump 36 to the head housing 50 and out of the piston rod end of the cylinder housing 50 into the reservoir 34 obviously other embodiments of the valve 40 are possible for example even valves separated from each other whose operation attains the same results as the valve 40 the interrupter valve 54 is configured as a two way two position valve and can be brought into a switch position u201c d u201d with a pressurized fluid opening 70 and a switch position u201c e u201d with a check valve 72 a spring 52 is provided on the interrupter valve 54 that always forces the interrupter valve 54 into its position u201c d u201d with free pressurized fluid flow the actuating device 42 is configured as a lever which can also be configured differently with other embodiments for example with cams tilting arms or the like the actuating device 42 is located in the path of movement of the switching device 44 and can be repositioned by this during the repositioning of the piston rod 48 when the actuating device 42 is grasped by the switching device 44 the interrupter valve 54 moves out of its position u201c d u201d into its position u201c e.