| 摘要 |
<p>1,242,004. Electric contacts. WESTINGHOUSE ELECTRIC CORP. 4 Nov., 1968 [13 Nov., 1967], No. 52085/68. Heading H1N. [Also in Divisions B3, C6-C7 and H3-H5] An electrical contact assembly comprising a contact button 39 on an arm 37 is produced by (1) melting the arm at the button securing region, (2) depositing metallic powder upon said region by plasma-jet torch to form the button, and (3) hardening the assembly by subjecting it to one or more cold working, e.g. pressing or coining, treatments. Hardening may also be effected by age or precipitation hardening. In a mass-producing arrangement shown, arm-forming strip 53 from a delivery reel 55 is transported, by drive rolls 57, through a straightener 65, and edge guides 67, under twin torches 21 operating under an exhaust hood 61, and through surface cleaning rolls 69, to a coining and shearing machine 71. One or both torches are operative respectively for welding contact material along the strip centre for producing staggered pairs of assemblies (Fig. 9, not shown) or along the opposite strip edges for producing transversely aligned pairs of assemblies. The arm 37 is of copper or copper chromium. The contact metallic powder may comprise one of the following (percentages by weight, where given):- 35-80% Ag, 20-65% W, 35% Ag, Cu, P (88, 10, 2%), 65% W. 35% Ag, Cu (90, 10%), 65% W, Ag, Si, 65% Ag, 35% Mo, 65% Ag, 35% SiC, Ag, WC, Ag, Ti, 90À25% Ag, 5% Cu, 4À5% CdO, Ag, TiC, Ag, Ag, Ni, Ag, Co. In a multi-layer assembly a layer of fine Ag powder is welded on to an initial layer of Ag, W. The Specification also includes examples of plasma and work arc power, arc gap, rate of plasma gas and powder feed, strip travel and arc oscillation, strip and button thickness, thickness reduction, cold working pressure, and resultant hardness; analyses of actual contact materials; and assembly tests for temperature rise, overload, short-circuiting and endurance.</p> |
