Abstract: A hydraulic, adjustable vibration damper for motor vehicles, with a damping piston fastened to a piston rod, which damping piston divides the work cylinder into two chamber halves filled with damping fluid, has a bypass located parallel to the valves of the damping piston. In the bypass there is at least one valve which reacts as a function of the pressure, and to control the bypass, there is a device to adjust a control body, which control body can be pressurized in the closing direction by a pressure medium. Between the pressure medium and the control body there can be an axially movable pressure intensifier which is sealed on its circumference, whereby corresponding to the pressure intensifier there can be an additional spring force which acts in the direction opposite to that of the pressure medium.

Abstract: An adjustable hydraulic vibration damper for motor vehicles includes a hydraulically and/or pneumatically adjustable control body of a damping valve which guarantees a continuous damping force adjustment, whereby when a control pressure falls below a minimum value, a high damping force is automatically generated. For this purpose, there is a control body for controlling passage of damping fluid through a flow channel, which control body has, on the side opposite the channel, a piston which works together with the control body, whereby a control pressure simultaneously presses against the neighboring end surfaces of the control body and of the control piston to provide a desired amount of damping force for control of the flow of damping fluid through the flow passage.