Gas spring and method of filling the same

Claim 2

A gas spring comprising, an elongated hollow cylinder having a closed end and an open end, a piston disposed within said cylinder, an elongated rod coaxial with said cylinder with a portion projecting into the cylinder through said open end and connected to said piston, at least one protuberance formed on the inner wall of said cylinder and spaced from said open end, an annular sealing member made of a flexible material and encircling said rod, said member normally being disposed between said protuberance and said open end, a first annular surface formed on said member and engaging said rod around its complete circumference thereby to form a seal between the member and the rod, and a second annular surface formed on said member and normally engaging the inner wall of said cylinder around the entire circumference thereof thereby to form a seal between the member and said wall, said member being operable when said open end communicates with a source of gas under pressure to move axially into engagement with said protuberance and forming openings between said second surface and said inner wall adjacent said protuberance whereby gas may flow through said openings and into the interior of said cylinder, the gas within said cylinder being operable when said source is removed from said open end to move said member toward the open end and out of engagement with said protuberance whereby said member seals the interior of said cylinder from said open end.

Claim 3

A gas spring as defined in claim 1 in which a plurality of protuberances are formed on said inner wall and are equally spaced around the wall and in which openings are formed adjacent each of said protuberances when the latter are engaged by said sealing member.

Claim 4

A gas spring as defined in claim 2 in which said protuberances are indentations in said cylinder.

Claim 5

A gas spring as defined in claim 1 in which said sealing member includes an integral generally cylindrical flange projecting axially from the periphery of said member and away from said open end and in which said second surface is formed on said flange.

Claim 6

A gas spring comprising, an elongated hollow cylinder having a closed end and an open end, a piston disposed within said cylinder, an elongated rod coaxial with said cylinder with a portion projecting into the cylinder through said open end and connected to said piston, a plurality of protuberances formed on the inner wall of said cylinder and spaced from said open end, said protuberances being equally spaced around said inner wall, a sealing ring made of a flexible material and encircling said rod, said ring normally being disposed between said protuberances and said open end, inner and outer generally cylindrical flanges of flexible material formed integrally with said ring and projecting axially away from said open end, a first annular surface formed on said inner flange and engaging said rod around its complete circumference thereby to form a seal between said ring and the rod, and a second annular surface formed on said outer flange and normally engaging the inner wall of said cylinder around the entire circumference thereof thereby to form a seal between said ring and said wall, a rigid annulus disposed in said cylinder between said ring and said open end and supporting said ring, said ring and said annulus being operable when said open end communicates with a source of gas under pressure to move axially and engage said outer flange with said protuberances thereby to form openings between said second surface and said inner wall adjacent said protuberances whereby gas may flow through said openings and into the interior of said cylinder, the gas within said cylinder being operable when said source is removed from said open end to move said ring and said annulus toward the open end and disengage said outer flanges from said protuberances whereby said ring seals the interior of said cylinder from said open end.

Claim 7

A gas spring comprising, an elongated hollow cylinder having a closed end and an open end, a piston disposed within said cylinder, an elongated rod coaxial with said cylinder with a portion projecting into the cylinder through said open end and connected to said piston, a plurality of protuberances formed on the inner wall of said cylinder and spaced from said open end, said protuberances being equally spaced around said inner wall, a sealing ring made of a flexible material and encircling said rod, said ring normally being disposed between said protuberances and said open end, inner and outer generally cylindrical flanges of flexible material formed integrally with said ring and projecting axially away from said open end, a first annular surface formed on said inner flange and engaging said rod around its complete circumference thereby to form a seal between said ring and the rod, and a second annular surface formed on said outer flange and normally engaging the inner wall of said cylinder around the entire circumference thereof thereby to form a seal between said ring and said wall, a rigid annulus disposed in said cylinder between said ring and said open end and supporting said ring, said ring and said annulus being operable when said open end communicates with a source of gas under pressure to move axially and engage said outer flange with said protuberances thereby to form openings between said second surface and said inner wall adjacent said protuberances whereby gas may flow through said openings and into the interior of said cylinder, the gas within said cylinder being operable when said source is removed from said open end to move said ring and said annulus toward the open end and disengage said outer flanges from said protuberances whereby said ring seals the interior of said cylinder from said open end.