US Patent 7237765 Speed limiting system for lifting devices

Speed limiter system to detect over speed and generate a signal to cut the power and if necessary operate brakes. It consist of the limiter itself, with a tension pulley. The limiter consists of weights connected by a mechanism that moves asymmetrically and by centrifugal force when an over speed occurs to operate the lever of an electrical contact, with the possibility of remote resetting using the necessary means. On the other hand, the tension pulley provides sufficient tension to both sections of the cable via an adjustable compression spring or by means of weights suspended on an articulated arm, both transmitting sufficient tension to the tension pulley axle.