Drive mechanism for timepiece hands - has one drive shaft for both hands, with hour hand attached via flexible spring element and supported on friction wheel

摘要

The drive mechanism for the hands of a timepiece uses only one drive shaft for both the hour and minute hands. The hour hand may be driven by the rotation of the drive shaft via a spring element fitted at one end to the drive shaft and at the other to the inner end of the hour hand. A friction wheel is pref. fitted to the other end of the hour hand and cooperates with a toothed annular track around the inner surface of the watch glass. Pref. the diameter of the driction wheel is such that, for each full rotation of the drive shaft, the hour hand rotates once about its own axis, causing it to move sideways by 1/12th of a full rotation of the hour hand about the clock face.