Abstract: A chuck drive system, especially for a rotating clamping device of a machine tool, includes a rotating chuck cylinder, a stationary frame positioned adjacent the chuck cylinder, and a piston which subdivides the cylinder into two pressure chambers and is formed with a piston rod having one end rotatably supported in the stationary frame. Fluid under pressure is supplied to the pressure chambers, whereby check valves are positioned in the passageways to the pressure chambers to maintain the fluid pressure in the pressure chambers. In order to monitor the fluid pressure in the pressure chambers, a pressure monitoring unit is provided which includes pressure sensors that are respectively assigned to the pressure chambers for determining the fluid pressure in the pressure chambers separately and independently from one another.

Abstract: For coupling and decoupling gripper rail parts in a transfer press, clamping means with a clamping bolt movable in its axial direction and rotatable about the same are arranged in the end parts. The clamping bolt engages with a clamping anchor behind a clamping surface in the end part to be coupled. Centering means for the mutual alignment of the gripper rail parts and of coupling device for the lines taken along at the gripper rail parts are movable along with the clamping bolt. The closing of the coupling devices in the line leading to the clamping means takes place sequentially. The movements of the clamping bolts after the closing of the coupling devices can take place at the same time.