Hydraulic shock-absorber and vibration damper with an inner tube

A hydro-pneumatic shock-absorber and vibration damper comprising a cylinder, an annular damping piston disposed inside the cylinder so as to be axially movable therein and dividing off two working chambers in the cylinder which are filled with a hydraulic damping medium, at least one throttle connecting the working chambers to each other, a piston rod in the form of a hollow cylinder mechanically connected to the damping piston and guided outwardly from the cylinder in sealing-tight manner, a compensating chamber connected to a first one of the working chambers for receiving a volume of damping medium displaced by the piston rod, a pneumatic spring chamber separated in sealing-tight manner from the compensating chamber by a freely movable floating piston and filled with a compressible medium, an inner tube extending with slight peripheral clearance through the annular damping piston and into the hollow piston rod so as to be inside the cylinder and coaxial therewith, the floating piston being guided inside the inter tube, wherein the free end region of the inner tube facing the outwardly-guided end of the hollow piston rod is closed in a gas-tight manner whereby the pneumatic spring chamber is bounded by said free end region of the inner tube and by the floating piston, and wherein the hollow piston rod has a vent opening in the part extending axially outwards of the inner tube.