| 摘要 |
1,218,059. Welding by pressure. AMF Inc. 15 Oct., 1968 [2 Nov., 1967], No. 48716/68. Heading B3R. In a method of welding a first metal part 10 of low thermal mass, i.e. wire, rod, strip, tube of relatively small cross-sectional metal area, to a second part 11, which may or may not be of low thermal mass, in which current passes from and to contacts 18, 19 to and from a weld point 23, a thermally and electrically conductive member 13, e.g. a roller or roller electrode, is maintained in contact with a substantial portion and preferably a quarter of the periphery of the first part 10 and with a portion of the first part farther from the facing surface of the second part 11 than a portion of the member 13, whereby part of the current flows along the member and the member acts as a heat sink for the portion of the first part through which the current flows. The roller 13, which may be cooled, is provided with a peripheral groove 12 whose side walls 26, 27 carry a portion of the current by virtue of their proximity to the current path in the second part 11. The contact 19 may supply current directly to the first part 10. The second part may be a strip or sheet (as shown), or may be a tube or rod. The first part may be welded along an edge of the second part (Fig. 5, not shown). In another embodiment (Fig. 7, not shown) a cylinder constituting the second part is provided with a helical first part applied by a roller having a plain periphery from one side only of which is a radially extending lip (60). In another embodiment (Figs. 8 and 9, not shown), a folded ribbon is welded along the fold, to a sheet. In yet another embodiment (Figs. 10-12, not shown), a tube or cylinder is provided with a helical fin. In yet another embodiment (Figs. 13 and 14, not shown), a filler strip (93) constituting the first part is applied to a butt seam between a second part (90) and a third part (91). The roller may be made of hard copper. The current may be high frequency or pulsed if a non-continuous weld is to be formed. |
