Shaft 1 rotates about fixed axis A-A. Rigidly attached to shaft 1 by means of collar 6 is crosspiece 5 in which pins 4 are fastened. Weights 2 with friction pads a turn about axes B of pins 4. Housing 3 is rigidly attached to the base. When shaft 1 starts to rotate at a speed higher than the permissible value, weights 2 are spread by centrifugal force, overcoming the resistance of spring 7, pads a are pressed against the inside surface of housing 3 and produce the braking effect that slows down shaft 1.
$3413$SmF,G$