JP2642097B

An adjustable-length gas spring has two compressed-gas-filled cylinders concentrically surrounding one another, with a piston and piston rod disposed in the inner cylinder thereof. A valve for effecting communication between housing chambers divided by the piston is provided at one end of the cylinders. This valve has a valve body, which is sealed with respect to the cylinders by means of outer ring seals. In order to avoid the danger that the gas spring may become useless from damage to one of the outer ring seals, it is provided that the valve body embodied as an injection-molded plastic part tapers-optionally in gradations-towards its axial ends, without radial protrusions, beginning at a region between the two outer grooves, that the outer groove associated with the inner cylinder is axially defined with respect to the adjoining housing chamber by the cap which is directly connected to the valve body and that the outer groove associated with the inner wall of the outer cylinder is defined axially with respect to the outside of the gas spring by a separate ring that is firmly joined to the valve body.