| 摘要 |
<p>705,626. Drilling ; punching. INTERNATIONAL RESISTANCE CO. March 3, 1952 [March 8, 1951], No. 5484/52. Classes 83 (3) and 83 (4). [Also in Group XXXVI] A tool for cutting discs from a sheet of laminated metals has an eccentric cutting edge so that in drilling an island is made in the sheet which may be completely cut out, or finally severed from the sheet by a punching operation. Drills and cutters.-The drilling tool comprises a cylindrical steel shank 44, Figs. 6, 7, tipped with a hard metal carbide insert 46. The cutting edge 47 slopes outwardly at a small angle, approximately 2 degrees ; the outside edge 50 also slopes outwardly at approximately 2 degrees, and the inside edge 51 slopes at approximately 60 degrees. The tip is machined to provide adequate top rake, side relief and bottom clearance. Punches.-The punching operation is performed with a female die 32, Fig. 5, with centering lips 34, and a punch 40, which punches the discs 22 into a tubular container 31 located by guide ribs 38. In a modification, Fig. 12, the die 132 is provided with an end button 58 having a flat surface 59 which, with a central bore 36, defines a circular cutting edge 134, slightly larger than the bore diameter of the disc 22, the punch 140 having a slightly smaller-diameter cutting edge 61. To minimize strain other than in the cutting plane, the end face 62 of punch 140 is recessed.</p> |
