| 摘要 |
PURPOSE: To improve the water absorbability of a gear made of synthetic resin and prevent dimensional change caused by humidity so as to provide a wrist watch gear made of synthetic resin, stable in dimensional accuracy. CONSTITUTION: An intermediate gear 8 and a third gear 10 are injection-molded out of polyacetal resin pellet containing potassium titanate whiskers mixed with silicone oil with heat resistance of 250 deg.C or higher by several percent. |
