Rotation is transmitted from shaft 1 through worm 2 and worm wheel 3 to shaft 13. This winds up a flat spiral power spring enclosed in casing 12. One end of the spring is secured to shaft 13 and the other to casing 12. The energy stored in the spiral spring is transmitted through gear 4, rigidly attached to casing 12, and gears 5, 6 and 7 to driven shaft 8. The speed of shaft 8 is controlled by spring-type centrifugal governor 9 which is driven through worm wheel 10 and worm 11.
$2969$CxG,FD$