Abstract: An arrangement for detecting a load bearing failure includes a primary load-carrying system for bearing axially translatably a coaxial load, said primary load-carrying system having a rotor portion and an axially displaceable stator portion. A plurality of bearing balls is interposed between the rotor and axially displaceable stator portions. A detector, which may include any of a laser measuring, an ultrasonic measuring, or a linear variable transformer or electrical contact detects wear or actual or impending failure of the primary load-carrying system. A secondary load-carrying system may be provided for bearing the coaxial load upon the event of a failure of the primary load-carrying system. The primary load-carrying system is a recirculating ball screw arrangement wherein the plurality of bearing balls is disposed in part in respective helical grooves of the rotor and axially displaceable stator portions. Wear or escape of the bearing balls is detected.

Abstract: A drive arrangement for a hemming press uses a ballscrew drive arrangement with a longitudinal axis. A first gimbal connected to the externally threaded screw shaft connects the externally threaded screw shaft to a stationary member. The platen is movable with respect to the stationary member. A second gimbal connected to the internally threaded nut connects the internally threaded nut to the platen. The gimbals accommodate transaxial displacement of the screw drive arrangement. A motor applies torque to the ballscrew drive arrangement. Transaxial loading of the screw drive arrangement is accommodated by the first and/or second gimbals. Severe forces resulting from crashes are accommodated by force limiting arrangements and resilient devices.

Abstract: A drive arrangement for a hemming press uses a ballscrew drive arrangement with a longitudinal axis. A first gimbal connected to the externally threaded screw shaft connects the externally threaded screw shaft to a stationary member. The platen is movable with respect to the stationary member. A second gimbal connected to the internally threaded nut connects the internally threaded nut to the platen. The gimbals accommodate transaxial displacement of the screw drive arrangement. A motor applies torque to the ballscrew drive arrangement. Transaxial loading of the screw drive arrangement is accommodated by the first and/or second gimbals. Severe forces resulting from crashes are accommodated by force limiting arrangements and resilient devices.