| 摘要 |
PURPOSE:To enhance holding force by increasing the diameter of the press- fitting part of a shaft and a gear in the train wheel of a timepiece. CONSTITUTION:A shaft 10 made of metal, wherein a flange-shaped large- diameter part 15 is formed, and a gear part 20 made of synthetic resin, wherein a through hole 23 into which the shaft 10 is inserted and a coupling recess part 24 into which the large-diameter 15 is press-fitted are formed on the same shaft, are provided. When the large-diameter press-fitting part 15 of the shaft 10 is press-fitted into the coupling recess part 24 of the gear part 20, the mutual compressing force between the outer surface of the large-diameter press-fitting part 15 and the inner surface of the coupling recess part 24 is increased, and the holding force of the shaft 10 and the gear part 20 is enhanced. |
