APPARATUS FOR TIGHTENING SCREWS OR NUTS BY MEANS OF AN A.C.MOTOR

摘要

Apparatus for tightening screws or nuts, driven by means of an asynchronous motor (2) at a medium frequency, provided with a switching device (7) on the lowest frequency of the network. The device (7) is provided with a regulator (8) which disconnects the device as soon as a torque detector (5) provides a signal indicating that a desired screwing torque has been obtained.