| 摘要 |
902,993. Making posts; sheet-metal joints; bending cutters. EXPANDED METAL CO. Ltd. March 21, 1961 [April 12, 1960], No. 10303/61. Classes 83 (2) and 83 (4). [Also in Group X] A method of joining together two sheet-metal members comprises placing a flat portion of one member back-to-back with a flat portion of the other member, cutting through the two contiguous flat portions at two places to form two spaced pairs of tabs, each pair consisting of two identical overlapping tabs, one of which is integral with one member and the other of which is integral with the other member, bending both pairs of tabs out of the planes of the flat portions in opposite directions towards the same side of the flat portions through 180 degrees, pressing the bent tabs and the flat portions together and forming a concave depression in them which extends across the bent edge of each tab. In an embodiment the central web sections 18 and 19 of a partitioning stud 15 are joined together at a number of places 22 by the method of the invention. Apparatus for carrying out the method comprises a punch and die assembly 44, Fig. 2. The web sections to be joined are supported on a die block 46 which co-operates with a U-shaped bending cutter 48 having cutting edges about the truncated conical surfaces 51, 52 of the limbs 49, 50. The bending cutter cuts two spaced double-thickness D-shaped tabs 56 and 57, Fig. 4, from the overlapping web sections and curls them inwardly toward one another on the under-side of the web as they are being cut. At the end of the curling operation a lower die 47 is raised to engage the tabs and co-operates with the bending cutter to compress the tabs against the webs and to impart a concave depression in the joint, Fig. 9, which prohibits the tabs from being lifted or bent outwardly when subjected to structural forces. |
