| 摘要 |
1481324 Making electrical contacts E I DU PONT DE NEMOURS & CO 6 Aug 1974 [9 Aug 1973] 34626/74 Heading B3A A method of attaching a metal element, W to form, e.g. an electrical contact C, to a metal member or strip S comprises, engaging an end portion of the element W with the member S, welding the member to the element thereby heating the element and removing heat from the element to establish a difference in temper along a boundary (B), Fig. 6 (not shown), adjacent the weld region and pulling the element to break it away from the member along the boundary leaving the end portion still attached. The strip S is fed intermittently over a welding electrode 17 and the element W, which is preferably a hard gold wire, is fed to an electrode 19 having opposing jaws. The electrode jaws are closed on the wire by a clamp 21 and an air cylinder 21 is activated to pivot the electrode 19 downwardly about trunnions 23. The strip is urged against the electrode 17 as the end of the wire is flattened and welded to the strip. The temper boundary (B) is established by the weld heat and by the removal of heat from the wire by the jaws. The clamp 21 is released, the jaws withdrawn approximately to the boundary (B) and the clamp reactivated. The electrode 19 is then withdrawn and the wire breaks along the temper boundary to form the contact C, which may be finally shaped by a coining member 25 and anvil 26. The method may also be used in the manufacture of gold plated electrical sockets. |
