| 摘要 |
A cylindrically enlarged end of an otherwise hexagonal steel nut has a shallow cylindrical depression in its radial seating face. Shallower recesses extend radially outward from the depression which partly receives a nylon ring in the relaxed condition of the latter. The portion of the ring which projects from the depression is frustoconical and its volume is not greater than the joint capacity of the shallower recesses. When used on a bolt for fastening a work piece receiving the bolt in an oversized opening, the ring material quickly seals any gaps between the bolt, the workpiece and the nut. Any excess ring material flows into the recesses and none is extruded into the narrowing gap between the seating face of the nut and the workpiece. The important conical shape of the ring is maintained during manufacture of the fastener by injection molding the ring, inserting it in the nut and exposing the latter to induction heating whereby only the surface of the ring is fused and bonded to the metal. |
