Patent ID: 7431134

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 the compensating medium ( 16 M) is selected such that its critical temperature (T K ) is between a first temperature (T 1 ) and a second temperature (T 2 ), with the first temperature (T 1 ) being substantially the same as the lower limit temperature (T lower ) of a range of operating temperatures of the gas spring ( 50 ), and the second temperature (T 2 ) exceeding the upper limit temperature (T upper ) of the range of operating temperatures of the gas spring ( 50 ) by approximately 100° C., and in that the surface (A 2 ) of the compensating piston arrangement ( 10 ) on which the compensating medium ( 16 M) acts, the surface (A 1 ) of the compensating piston arrangement ( 10 ) on which the working medium ( 1 M) acts, the volume of the working chamber ( 1 a ) at a design temperature of the gas spring ( 50 ), the volume of the compensating chamber ( 16 ) at the design temperature of the gas spring ( 50 ) and the restoring force of the restoring medium ( 15 M) acting on the compensating piston arrangement ( 10 ) at the design temperature of the gas spring ( 50 ) are dimensioned and matched to one another such that, at an operating temperature (T B ) of the gas spring ( 50 ) which does not exceed the critical temperature (T K ) of the compensating medium ( 16 M), the point indicating the state of the compensating medium ( 16 M) lies on or above the vapor pressure curve.