| 摘要 |
765,651. Drills. ASPLUND, J. A., [trading as MASKIN-, FIRMA R. L. CARLSTEDT]. June 14, 1954], [June 15, 1953], No. 17376/54. Addition to 760,353. Class 83(3). A drill comprises a tube 12 carrying an insert 14 having a cutting edge 18 and two integral guiding abutments 20, 22 at right angles to one another. The tube is cut away at 26 to facilitate the removal of cuttings. The abutments are tapered circumferentially to provide an oil-pocket at their leading edges. |
