MAINSPRING FOR TIMEPIECE, POWER DEVICE FOR TIMEPIECE, MOVEMENT FOR TIMEPIECE, TIMEPIECE, AND MANUFACTURING METHOD FOR MAINSPRING FOR TIMEPIECE

摘要

PROBLEM TO BE SOLVED: To provide a mainspring for a timepiece which is hard to be subjected to fatigue destruction, and a power device for a timepiece, a movement for a timepiece, a timepiece and a manufacturing method for a mainspring for a timepiece.;SOLUTION: A mainspring for a timepiece being accommodated in a barrel, having an inner end fixed to a barrel arbor which the barrel comprises, and having an outer end engaging with an inner wall of the barrel comprises a spiral portion wound in a Bernoulli curve from the inner end in a free state in which a load is not applied thereto.;SELECTED DRAWING: Figure 12;COPYRIGHT: (C)2018,JPO&INPIT