Worm wheel 1 rotates about fixed axis B and meshes with worm 2 which is keyed to hollow shaft 8 and rotates about fixed axis A. Driven shaft 9 rotates about axis A and is driven, at normal load, by means of flanges 3 and 4, keyed to hollow shaft 8, and balls 5 which are held in cage 10 and engage grooves in flange 4, Cage 10 is keyed to driven shaft 9. Balls 5 are held in the grooves by pressure member 6 and spring 7. In case of overload, the balls are forced out of the grooves, compressing spring 7, and shaft 9 stops until the torque load drops below the permissible value.
$3449$CF,C$