Abstract: In the case of a control system for a hydraulic element (14) which, under the pressure of hydraulic fluid in a locking pressure space (16) on one side of the hydraulic element (14) enters into an unlocking pressure space (13) on the other side of the hydraulic element (14), wherein the two pressure spaces (13, 16) are connected via a respective line (19) and (20) to the same main line (3, 4), a pressure-regulating valve (18) is to be connected into the line (19) to the unlocking pressure space (13), preventing the fluid from flowing back out of the unlocking pressure space (13). Furthermore, a pressure-compensating valve (21) is to be connected into the line (20) to the locking pressure space (16).

Abstract: A lockable working cylinder comprising a housing and a piston that can be displaced in a primary pressure chamber of the housing. A piston rod tube leads from the piston out of the pressure chamber and a spindle rotates in the piston or piston rod tube, the spindle being allocated to a unit that halts the rotational displacement. The spindle or a rotational sleeve that is placed over the spindle has a radial pressure chamber, in which a locking bolt engages, said bolt being introduced radially.