| 摘要 |
PROBLEM TO BE SOLVED: To provide a structure for stabilizing the slip torque of wheels of a timepiece. SOLUTION: A pair of elastic arm sections 2 and 3 having a fixed width B is formed in a center toothed wheel 1 so that both circumferential sections 1b and 1b are connected. Curvature sections 2a and 3a having an internal diameterϕd are formed at the center of the elastic arm sections 2 and 3 for elastically pinching a minute pinion. Near a connection section where the elastic arm section 2 is connected to the circumferential sections 1b and 1b, narrow- width sections 2b and 2c of width (b) are formed by arc cutout sections 2d and 2e, and narrow-width sections 3b and 3c are formed at a portion where the elastic arm section 3 is connected to the circumferential sections 1b and 1b so that the narrow width sections 3b and 3c oppose the narrow width sections 2b and 2c. The presence of the narrow-width sections 2b, 2c, 3b, and 3c allows the spring constant of the elastic arm sections 2 and 3 to decrease, and allows variation in strip torque to decrease. COPYRIGHT: (C)2003,JPO
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