Shaft 2 rotates about fixed axis A-A. Shaft 2 is driven from gear 7 which rotates about fixed axis B and meshes with gear 1. Gear 1 rotates about fixed axis D and is rigidly attached to worm wheel 8 which meshes with worm 9 having a large helix angle. Sleeve 10 with friction disk 6 can slide along shaft 2. The left ends of flat springs 11, carrying weights 3, are attached to sleeve 10. The right ends of the springs are attached to collar 12 which is rigidly clamped on shaft 2 by screw 13. The required maximum speed of shaft 2 is set by turning lever 5 about fixed axis C. Lever 5 carries braking shoe 4 against which disk 6 is pulled by springs 11 when the speed of shaft 2 exceeds the maximum value.
$3455$CF,G$