| 摘要 |
1,163,077. Files; making files; punching. OATEY CO. 11 April, 1968 [30 Jan., 1968], No. 17698/68. Headings B3A, B3L and B3W. A rasp file is formed by punching cutting edges 3 and square openings 5 in alternate pairs of diagonal rows 6 which are longitudinally aligned and intermediate pairs of diagonal rows 7 which are staggered with respect to the rows 6 so that the cutting edges 3 overlap during a cutting stroke. The file may be flat or curved transversely. The file may be used on plastics, wood and metal. The cutting edges 3 and openings 5 are formed by a punch and die (10), (11), (Fig. 4, not shown), the cutting edge being formed by a radiused edge (14) on the die. The file may be formed by a pair of punch and dies operating successively on different rows and the file being indexed therebetween. |
