Patent ID: 7628255

Claim:
A gas spring ( 50 ), comprising a working cylinder ( 1 ) which, together with a compensating piston arrangement ( 10 ), delimits a working chamber ( 1 a ) filled with a working medium ( 1 M), and a working rod ( 6 ) which projects displaceably through an opening in the working cylinder ( 1 ) into the working chamber ( 1 a ), in which the compensating piston arrangement ( 10 ) is acted upon by the pressure of the working medium ( 1 M) and the pressure of a compensating medium ( 16 M), which is provided in a compensating chamber ( 16 ) and expands if the temperature rises such that the volume of the working chamber ( 1 a ) increases, and by a restoring medium ( 15 M), which is provided in a restoring chamber ( 15 ) such that the volume of the working chamber ( 1 ) decreases, characterized in that it further comprises a compensating cylinder ( 12 ) which surrounds the working cylinder ( 1 ) at a spacing therefrom, extends beyond the working cylinder ( 1 ) by means of its end ( 1 c ) remote from that end ( 1 b ) of the gas spring ( 50 ) at which the working rod comes out and is closed at this remote end, with the compensating chamber ( 16 ) formed substantially by the annular chamber between the working cylinder ( 1 ) and the compensating cylinder ( 12 ), and in that the compensating piston arrangement comprises a single compensating piston ( 10 ) which is displaceably received in the compensating cylinder ( 12 ) and takes the shape of a cup, with a cup base ( 10 a ) and a cylindrical portion ( 10 b ), which projects away from the cup base ( 10 a ) in the direction of the end ( 1 b ) at which the working rod comes out, and which engages with the working cylinder ( 1 ), and with the compensating piston ( 10 ) separating the working chamber ( 1 a ), the compensating chamber ( 16 ) and the restoring chamber ( 15 ) from one another.