Fluid pressure actuator and actuator system

摘要

A fluid pressure-operated actuator comprises a cylinder body containing a piston slidable therein, the piston defining respective chambers at opposite sides thereof. A rod projects from one side of the piston and extends through an end wall of the cylinder and a plunger is slidable on the rod and also extends through the end wall. The arrangement is such that the application of fluid pressure simultaneously to the chambers results in movement of the piston lengthwise of the rod, the piston movement including a first part during which the plunger applies force to the rod in addition to that arising on the piston, and a second part during which the force from the plunger is absent.