Abstract: A compression spring comprises a casing with a piston that is mounted on a piston rod being disposed for displacement therein. Two sectional casing chambers are provided in the casing, which are filled with pressure fluid and at least one of which is defined by the piston. A controllable first valve interconnects the sectional casing chambers in an open position and blocks the compression spring in a shut-off position. By way of an additional automatic valve between the sectional casing chambers, the compression spring, even when blocked, can be adjusted in the piston-rod push-out direction by a force being applied that is comparable to the push-out force that works in the push-out direction by the pressure of the pressure fluid. This provides for greater flexibility in use of the compression spring.