| 摘要 |
<p>Contacts are made coated with precious metal on a limited local zone. Hexagonal bar of an electrically conducting material is coated on one of its six faces with precious metal. The bar is then rolled, drawn, or rolled and drawn into profiled wire; the wire is soldered along a fixed length to a support and cut, followed by rivetting or stamping to obtain a hemispherical contact. The faces of the hexagon which will be welded to the support are pref. made concave so that at the start of welding the wire only rests by two edges on the support. An electrode with a V-shaped profile is pref. used to weld the hexagonal wire onto the support when the precious metal coating is next to the surfaces in contact with the electrode, i.e. so the electrode does not touch the precious metal. Used for e.g. gold coated contacts, where only one of the six flats is coated to use the min. amt. of Au, and also to permit oblique contact, e.g. with the periphery of a tubular contact.</p> |
