TW343168B - A pneumatic actuator device - Google Patents

Abstract

A pneumatic actuator device mainly comprising an actuator body (10), pressurized fluid feed means injecting gas to the actuator body under pressure, a first piston (18) movable in first axial chamber (12) situated at the rear end of the actuator body, a second piston (20) movable in a second axial chamber (14) situated in front of said the first; the device further comprising a separation wall (28) between the two axial chambers through which there slides a rod (24) inter-connecting the pistons (18,20) and an advance member connected to the pistons and situated at the front of the actuator body (10); pressurized fluid feed means including a slide valve (7) controlled by control means and moving between two positions; the separation wall (28) having a transverse bore (72) in which the slide of the valve (70) is received, a first duct (74,76) which connects the transverse bore (72) to a pressurized fluid feed, a second duct (82) which connects the transverse bore (72) to the rear portion of the second axial chamber, and a third duct (84) which connects the transverse bore (72) to the front portion of the first axial chamber (12); the first and second ducts (74,76;82) being in communication with each other and being isolated from the third duct (84) when the slide of the valve is in a first position, while the first and third ducts (74,76;84) being in communication with each other and isolated from the second duct (82) when the slide is in a second position.