Press driven tool actuator module

摘要

For a hydraulically actuated device a hydraulic power cylinder (30) with an actuator (14) slidably received for reciprocation within the cylinder (30) and a piston (68) slidably received for reciprocation within a sleeve (54) of the actuator (14) and defining a gas chamber(66) on one side of the piston (68) and a hydraulic fluid chamber (48) on the other side of the piston (68) so that the maximum pressure in the hydraulic fluid chamber (48) is limited as a function of the force of compressed gas in the gas chamber (66) acting on the piston (68). In this way, the maximum system pressure is a function of and substantially corresponds to the pressure of the compressed gas within the gas chamber (66) and acting on the piston (68). Desirably, the pressure of the compressed gas in the gas chamber (66) can be readily changed to change the maximum hydraulic fluid pressure. <IMAGE>