Abstract: A damper cylinder is partially filled with highly compressed gas and with operating fluid. A damping piston and connected rod portion are reciprocally movable in the cylinder operating fluid. A partition wall is fixedly mounted in the inner periphery of the cylinder and is interposed between the piston and a highly compressed gas chamber in the cylinder. The partition wall has valves opening in turn during the in and out movements of the damping piston and rod; the valve which opens during the outward movement of the working piston and rod having a closing force approximately equal to the product of such compressed gas and the effective cross-section of such outward movement valve.