Rotating double acting air cylinders the jaws manufacturing come as common means of actuating power chucks for to and fro movement mechanism on turning machines. These pneumatic rotary cylinders are available with a construction like chuck mounted on spindle nose of turning centre/lathe; cylinder mounted on spindle rear side; and piston with longitudinal movement and force transferred into radial jaw movement and force in the chuck by diagonal wedge hook and lever action. The rotary cylinders work in a way with the jaws for upward movement for clamping a component on the outer diameter and the piston performs a stroke until the jaws rest on the work piece and the full clamping pressure is built up. Clamping pressure is upheld in the cylinder during the whole clamping cycle and pressure is diverted to the rear of the piston for moving the drawbar between the chuck and piston in an opposite direction at the time of opening the jaws. The sequence of the clamping rings operation is reversed when clamping from inside is in the outward direction.
