Self-winding electric power generation watch with additional...
Self-winding watch
Self-winding watch
Spiral spring for time measuring device
Spring winding gearing including a safety mechanism against raci
Spring, mainspring, hairspring, and driving mechanism and...
Spring, power spring, hair spring, driving mechanism...
Spring-barrel arrangement for a timepiece
Spring-barrel arrangement for a timepiece
Spring-barrel supplying constant torque
Stabilising of an electronic circuit for regulating a mechanical