| 摘要 |
<p>A rod is cut into short pieces forming blanks which will be pressed into balls. The press tools consist of two endless roller chains (1) driven along oval paths. Each chain carries a row of tool holders (4); and each holder (4) contains a spring-loaded die half (5)moved by a roller (8). The rollers (8) travel along an oval cam (2), one cam (2) being located in the middle of each chain (1), so that dies (5) can be squeezed together to convert the rod blanks into balls. Balls for ball bearings can be made at speeds of 2000-25,000/ minute.</p> |
