Pneumatic chuck assembly

摘要

A rotary chuck having a chuck body supporting a plurality of clamping jaws for movement between open and closed positions and defining a cylindrical piston chamber containing an axially movable double acting piston coupled to a jaw actuator. A plurality of springs contained within the piston chamber apply biasing force to the piston in one axial direction to urge the jaws toward closed positions. An incrementally adjustable pneumatic control system is operable to apply pressure to the piston in opposition to the springs to reduce the resultant clamping force applied by the jaws in closed position. The control system is also operable to act in consort with the springs to increase the resultant clamping force applied by the jaws in closed position.