Self contained gas spring interchangeable with coil spring

A self contained gas spring interchangeable with a coil spring comprising

• a cylindrical body having a substantially constant diameter external cylindrical surface,
• said cylindrical body having open ends and an inner surface,
• a one-piece piston having an end and an integral side wall having another surface,
• said piston being inserted in said cylindrical body and having one closed end projecting through one of the openings of the cylindrical body,
• a plug positioned in the other end of the cylindrical body to close the opening of the cylindrical body,
• an axial charging valve positioned in the plug for charging the interior of the gas spring,
• said piston having a hollow inner end with an inner surface having a lower portion of the inner surface thereof tapering outwardly and axially toward said plug,
• the plug having a central portion projecting axially toward said piston and having a generally complementary surface such that side wall of the the piston can move downwardly about the central portion of the plug thereby substantially reducing the height of the gas spring,
• said plug having an axially outwardly extending opening,
• said one-way charging valve supported in said plug entirely within the confines of said opening in said plug,
• said gas spring being capable of being inserted in a cylindrical opening of a base member such that it is interchangeable with a coil spring in said opening,
• said gas spring including a threaded recess in the outer end of said piston for receiving a threaded tool to facilitate lifting of the gas spring out of the opening into which it has been placed,
• said gas spring including circumferentially spaced grooves in the end of said cylindrical body adjacent said one end of said piston extending axially toward said plug and radially outwardly for passage of oil and debris and for engagement of the tool,
• said piston having an integral outwardly extending radial flange on the external surface thereof,
• said cylindrical body having an integral inwardly extending first flange on the inner surface thereof adapted to interengage the flange on said piston to limit the outward movement of said piston relative to said cylindrical body,
• a second flange on said piston and a bearing between said second flange and said first flange on said piston,
• a second flange on said cylindrical body and a seal interposed between said second flange and said first flange on said cylindrical body.