Patent ID: 8444122
Filing Date: 2013-05-21
Classification: F16F

Abstract:
1. A gas spring, comprising: a casing having an open end and an inner surface defining in part a gas chamber; a piston rod received at least partially in the casing for reciprocation along an axis between extended and retracted positions, the piston rod having a first portion with a closed end and extending out of the casing at least in the extended position and a separate second portion formed separately from the first portion and connected to the first portion for movement in unison therewith along the axis, and at least the second portion defining a hollow space continuously communicating with the gas chamber; a rod guide carried by the second portion of the piston rod, received in the gas chamber and slidably engaging the inner surface of the casing to guide the reciprocation of the piston rod at least in part; a first stop carried by and within the casing adjacent the open end of the casing; a second stop carried by the piston rod between and spaced from both the closed end of the piston rod and the rod guide, separate from the rod guide and engaging the first stop when the piston rod is in its extended position; a bearing received between the first portion of the piston rod and the casing and carried by the casing adjacent the open end of the casing to guide reciprocation of the piston rod at least in part; the first stop is spaced from and does not engage the bearing and the second stop is spaced from and does not engage the rod guide carried by the second portion of the piston rod; a seal between the piston rod and the casing to prevent gas leakage from the gas chamber; and at least one passage through the rod guide and continuously communicating with the gas chamber to prevent the rod guide from restricting gas flow in the gas chamber during movement of the piston rod between the extended and retracted positions of the piston rod.