Timepiece with additional stop watch facility - has hollow minutes shaft and second minutes hand for stopwatch function

摘要

The hollow minutes shaft has a second coaxial shaft for the second minutes hand sliding coaxially within it, and projecting from it at either side. Each of the two shafts carries a coupling disc, via which the two shafts can be coupled to rotate together, the coupling disc for the inner shaft being larger than that for the hollow shaft. The two coupling discs are pref. coupled together by actuating operating means employing two lever arms, one of which engages the end of the inner shaft and the other engaging the outer edge of the coupling disc secured to the latter.