| 摘要 |
PURPOSE:To manufacture a locking nut quickly and cheaply by eliminating diagonal V-shaped cutting process and replacing it with simple outer peripheral cutting. CONSTITUTION:A crownlike part 3 is formed on one face of a nut 1 by facing 2 of proper depth. Outer circumference of diagonal part is cut to circular form as a whole and to slant widening outward toward other face of the nut, and slanted faces 3a are formed. The thickness of the crownlike part 3 is nearly uniform at the tip. However, the thickness of diagonal part increases toward the base, and center of the opposite side becomes thinnest. Then, the crownlike part 3 is caulked inward by a die D provided with a concavity Da having semicircular sectional form, and inner circumference of the crownlike part 3 is made to hexagonal form similar to the nut 1. Thread 3b which is the same with the thread of the nut 1 is treaded on inner circumference of the tip of the crownlike part. Then, the crownlike part 3 is caulked inward deeper than preceding time by the same die D to reduce inner diameter of the threaded part 3b. |
