Spring force applying actuators.

摘要

A spring force applying actuator has a fluid pressure responsive piston (208) between which and one end of the housing (204) there is a compressed heavy spring (211), fluid pressure can be applied via a port (210) in a sense to counteract the spring, the piston is slideable on a tubular tensional force output member (221) extending through said one end and within which there is a coupling mechanism for locking the piston thereto and the other end (220) of the output member extending rearward through the end (207) of the housing and providing accessibility to means for unlocking the coupling means for unloading the spring force from the output member.