| 摘要 |
713,625. Sheet-metal joints. WILLIAMS, I. A. Dec. 31, 1952, No. 33103/52. Class 83 (4) Shearing.-In uniting metal and other sheets by interengaging formations a punch 12a co-operates with bevelled discs 14 resiliently held on a shaft 15 by spring washers 22 to slit sheets 10, 11, and form recesses on the under side of the sheet 11. The end of the punch then co-operates with an anvil 13 having a tapered projection 13d which indents and widens the slit portion, without reduction of its original thickness, to lock the sheets together. The discs 14 are loosely mounted on the shaft 15 and abut on to shoulders 18 on the anvil 13. Spaces 17 allow clearance of waste and a groove 19 in the shoulders 18 protects the cutting edge of each disc. In an embodiment the discs may be replaced by rectangular flat plates 34 (Fig. 9). The penetration of the slit portion may be effected by a penetrating member 48 co-operating with a flat topped anvil 49 (Fig. 11). Specification 708,236 and U.S.A. Specifications 2,288,308 and 2,254,558 are referred to. |
