GB1378394A - Disposable resistance welding cap electrodes - Google Patents

Abstract

1378394 Welding by pressure P R MALLORY & CO Inc 7 Dec 1971 [18 Dec 1970] 56832/71 Heading B3R A composite disposable resistance welding cap electrode comprises a holder member shaped to fit on to or into an adaptor and made of 5005, 6061 or 6063 (Aluminium Association), alloy, zinc, zinc base alloy, iron or iron base alloy and having an insert tip inserted in a bore in the holder, the tip being made of an electrically and thermally conductive material having a greater strength at operating temperatures than the holder member. In an embodiment, cooling fluid, e.g. water, alcohol, air or nitrogen is passed through a hollow member 30, Fig. 1, into the channel formed between the member 30 and the bore 11 of the holder 10, an enlarged portion 14 of the holder forming a heat sink for the insert tip 20. The tip may or may not contain a coolant channel 21 in the insert portion 24 thereof which portion may be a square, rectangular, elliptical, multi-sided or circular cross-section and may be pressure fitted in the bore, brazed or fitted by tapering, knurls or splines. The working part of the tip may be part-spherical or may be flat and offset from the axis of the tip. Electrode adaptors 350, Fig. 3, which carry cap electrodes 310 according to the invention are carried in adaptors on arms 301, 302 of a welding machine, the adaptors being connected to cooling systems. The insert tip and holder may be machined from rod, die-east, extruded or sintered and the insert may be of copper, copper alloyed with one or more of chromium, zirconium, beryllium and cadmium, tungsten or molybdenum or alloys thereof, tungsten or molybdenum infiltrated with copper or silver, or alloys of silver, gold or platinum.