Freely mounted on shaft 1 is gear 4 to which drum 3 is rigidly attached. Flat spiral spring 2 is fastened at one end to the inside wall of drum 3 and at the other to shaft 1. The spring is wound by turning shaft 1 clockwise about fixed axis A. Spring 2 is held in the wound position by ratchet wheel 5, keyed on shaft 1, and pawl 6 which turns about fixed axis B. As it unwinds, spring 2 rotates drum 3 and gear 4 clockwise.
$2665$RG,3L$