Patent ID: 6378848
Filing Date: 2002-04-30
Classification: B60M,F16F,H02G

Abstract:
A gas spring apparatus comprising:an outer tube including an end wall formed having a hole; a cylinder held in the outer tube and having a cylindrical peripheral wall, a proximal end portion fixed to the outer tube, and a closed distal end face opposite the proximal end portion; a rod inserted into the outer tube through the hole in the end wall of the outer tube and having a distal end portion projecting inside the cylinder and a proximal end portion projecting outside the outer tube; a sealing portion provided on the inner periphery of the hole in the outer tube into which the rod is inserted; a piston provided on the distal end portion of the rod and dividing the interior of the cylinder between a first liquid chamber situated on a side of the sealing portion and a low-pressure gas chamber situated on a side remote from the sealing portion, wherein the low-pressure gas chamber is defined by the cylindrical peripheral wall, the distal end face of the cylinder and the piston, and the low-pressure gas chamber is charged with an inert gas whose pressure is higher than an atmospheric pressure; a metal bellows capable of extension and contraction in an axial direction of the outer tube and dividing the interior of the outer tube between a second liquid chamber and a high pressure gas chamber in which a gas is charged at a higher pressure than in the low-pressure gas chamber; and a liquid communicating portion internally connecting the first liquid chamber in the cylinder and the second liquid chamber in the outer tube.