Patent ID: 7428953

Claim:
A gas spring with end position damping, comprising: a cylinder defining an interior space filled with a fluid under pressure and having an inner wall extending between an outer end and a closed inner end; a rod sealingly extending from within the cylinder through the outer end of the cylinder, first and second pistons fastened to the rod so that the second piston is axially spaced from the first piston towards the inner end of the cylinder, the first and second pistons being axially displaceable with the rod along a path, the first and second pistons forming a piston assembly dividing the interior space into first and second cylinder chambers, each of the first and second pistons comprising: axially spaced first and second walls defining an annular groove therebetween, the second wall having a plurality of continuously throughflow openings, and a sealing ring received in the annular groove so as to bear against the inner wall of the cylinder and be axially movable within the annular groove, the sealing ring and the rod defining a passage therebetween in flow communication with the plurality of continuously open throughflow openings in the second wall, wherein the second wall of the first piston faces the first cylinder chamber and the second wall of the second piston faces the second cylinder chamber, whereby the first and second pistons are arranged in diametrically opposed positions on the piston rod; and at least one axial recess extending in the inner wall of the cylinder over the path of the pistons, the at least one axial recess being configured with a middle cylindrical region and opposite frustoconical end regions, the end regions narrowing towards respective opposite outer and closed inner ends of the cylinder.