BALANCE WITH HAIRSPRING, MOVEMENT, AND TIMEPIECE

摘要

PROBLEM TO BE SOLVED: To provide a balance with a hairspring for timepieces capable of changing an inertia moment of a balance wheel without getting lopsided.SOLUTION: A balance 1 with a hairspring including a balance staff 4, and a balance wheel disposed around the balance staff 4, includes: a first rim 6 constituting the balance wheel and having a guide 14, the distance from the balance staff of which is changed according to the circumferential direction around the balance staff; an elastic part 30 that is disposed slidably along the guide part, and is elastically deformable in the radial direction, with the balance staff 4 used as a center; and a second rim 18 having a plurality of weight parts 28 disposed in the circumferential direction.