Topic summary
Clockwork motor
Extracted from the Wikipedia article Clockwork.
A clockwork mechanism is often powered by a clockwork motor, consisting of a mainspring, a spiral torsion spring of metal ribbon. Energy is stored in the mainspring manually by winding it up, turning a key attached to a ratchet which twists the mainspring tighter. Then the force of the mainspring turns the clockwork gears, until the stored energy is used up. The adjectives wind-up and spring-powered refer to mainspring-powered clockwork devices, which include clocks and watches, kitchen timers, music boxes, and wind-up toys.