| 主权项 |
1. A gas spring for forming equipment, comprising:
a casing including an axially extending side wall, an open end, a transversely extending closed end wall axially spaced from the open end, a pressure chamber established in part by the side and end walls to receive a gas under pressure; a piston rod received at least in part in the casing for reciprocation between extended and retracted positions and having an inner end communicating with the pressure chamber and an outer end extending generally axially outwardly of the open end of the casing when the piston rod is in its extended position; a piston rod housing received at least in part in the open end of the casing between the piston rod and the casing, slidably received in the casing and having an interior end communicating with the pressure chamber and an exterior end axially spaced from the interior end and adjacent the open end of the casing, and slidably receiving the piston rod; and an overtravel pressure relief feature including a vent path that is disposed between the pressure chamber and the outside of the gas spring and that includes a vent passage through the side wall of the casing and a seal that sealingly interrupts the vent path, and in an overtravel condition of the piston rod, the piston rod housing is displaced into the casing and opens the vent path to the exterior of the casing. |
