Spring device and timepiece

Abstract

A spring device having an inside-end wheel that moves in conjunction with the inside end of a mainspring; an outside-end wheel that moves in conjunction with the outside end of the mainspring; a torque return unit that transfers part of the output torque of the mainspring from one to the other of the inside-end wheel and outside-end wheel; a duration time indicating unit that operates in conjunction with both the inside-end wheel and outside-end wheel and indicates the number of winds in the mainspring; and a torque transfer clutch unit that disengages torque transfer between the inside-end wheel and outside-end wheel by means of the torque return unit when the mainspring unwinds and the duration time indicating unit indicates a predetermined reference number of winds.

Dependencies are inferred from the claim text.