Abstract: An operation control device is provided for a chuck by which the rotary drive for the chuck is disengaged when the clamping motion leading to clamping of the workpiece in the chuck has not been provided or is not sufficient. The clamp jaws of the chuck are adjustable by a drive member guided axially in the chuch body which is connected to a clamping piston. The operation control device comprises a control piston which is acted on by a compressed medium against the force of a restoring spring and is locked by the drive member against the sliding caused by the compressed medium in a locked position disconnected from the rotary drive if the drive member is positioned in the end safety region of its axial displacement.

Abstract: The clamp jaws radially adjustable by a drive member each comprise a jaw base guided in the chuck body and a mounted jaw member replacably attached with it as well as at least one connecting pin which is mounted pivotable about the pin axis in the jaw base. According to rotary position the attachment between the jaw base and the mounted jaw member is released or locked. At least one control rod guided longitudinally slidable in the jaw base is coupled with the connecting pins by gear teeth so that the motion of the control rods relative to the jaw base converts to a rotation of the connecting pin and vice versa. The feed of the control rods in the jaw base runs parallel to the feed of the jaw base in the chuck body. For the control rod a controlling member is provided by which the control rod is held fixed from motion relative to the chuck body. The jaw base is slidable for rotation of the connecting pins by its drive member with the control rods held fixed in position.

Abstract: A power chuck has a chuck body rotatable about an axis, forming at least one cylinder, and having a front face. A plurality of jaws are displaceable radially on the front face between radially inner and outer end positions by an operating member axially displaceable on the body between a pair of axially offset end positions. Mechanism between the jaws and the member displaces the jaws toward the radial inner positions on displacement of the member in a first axial direction and displaces the jaws toward the radial outer positions on displacement of the member in a second axial direction opposite the first direction on the body. A drive piston the one cylinder of the body is fixed on and axially jointly displaceable with the member and forms in the one cylinder at least one compartment pressurizable to urge the drive piston and the operating member in one of the axial directions.