| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a spiral spring for a time piece, capable of minimizing fluctuation of output torque accompanying release (unwinding) and easy to manufacture, and a mechanical time piece equipped with this spiral spring. <P>SOLUTION: A spiral spring 1 for a time piece of a mechanical time piece includes a spiral spring body 30 comprised of a slender plate-like body 31 made of an elastic material. The spiral spring body 30 having an outer peripheral side end 32 engaged with a barrel and an inner peripheral side end 33 engaged with a core is bent along a bending line B extending in a longitudinal direction J at least in a part of a longitudinal direction region Qi such that a bending angle θ increases toward the inner peripheral side end 33. The longitudinal direction region Qi includes a part close to the inner peripheral side end 33 engaged with the core of the spiral spring body 30. The maximum value of the bending angle θ is equal to or less than 25 degrees. <P>COPYRIGHT: (C)2012,JPO&INPIT |
