| 摘要 |
PURPOSE: To prevent the breakage of a shoulder tapper having a flexible part and to improve the durability by providing a spiral part around the shaft of a flexible material. CONSTITUTION: A shoulder tapper has a grasping part 2 and an operating part 3 at both the ends of a flexible part 1. The part 1 is made of nylon 6 and has a spiral part 1b around a shaft 1a. The vertex of the part 1b is rounded. The part 2 is made of synthetic rubber and gradually thickened toward the end. The part 3 is also made of the rubber and has a rod part 3a thickened toward the end side and a spherical tapping part 3b. The part 1 is molded in a predetermined shape by inserting the nylon 6 into a mold, and then dipped in hot water of 90 deg.C for about 2 hours to be manufactured. Since the part 1 is spirally designed, when the one end side is fixed and belt, a force is dispersed to the entirety. Accordingly, the force is not concentrated to the part of the part 1 to be broken, and excellent durability is provided. |
