GB708624A - Improvements in or relating to resistance welding electrodes - Google Patents

Abstract

708,624. Making spot welding electrodes. WELDING CONTROLS, Ltd., and TOWNSEND, P. W. Aug. 3, 1951 [Aug. 10, 1950], No. 19927/50. Classes 83 (2) and 83 (4) Jointing; jointing by forging; soldered and brazed joints.-In a resistance welding fluid cooled electrode comprising a tubular body and a separately made tip closing the bore of the body, the tip has a projection which is secured in the bore by a cold pressure weld or a higher pressure force fit. In an embodiment a copper alloy tip 2, Fig. 1, having a recessed shank 2a is placed within a copper tube 1 and a swaging tool is applied internally and/or externally of the tube 1 to effect a cold pressure weld between the shank 2a and the tube 1. When the tool is applied internally it engages the recess 3 in the shank. In a modification an annular groove 4, Fig. 2, is formed in the tube 1 and during cold welding metal from the shank 2a flows into the groove 4. The groove may be on the shank. External knurling may be provided on the tube 1 and tip 2. In a further embodiment a ring of soft solder &c. 7, Fig. 5, is placed between the tip 2 and tube 1. The tip 2 and tube 1 are pressed together so that the washer 7 forms a seal to which controlled and localized heating is applied before cold welding of the shank 2a and tube 1 is commenced. In a modification the washer has a circular section and is applied between bevelled surfaces on the tube 1 and tip 2. In a further embodiment the tip 2 may be tapered at 8, Fig. 7, to fit a taper 9 on the tube 1. Axial pressure is set up between the tapered surfaces to cold weld them. The applied pressure may not result in cold welding but merely in a very tight fit which is satisfactory. According to the Provisional Specification where a soft solder washer is employed a lower pressure may be used for joining the tip and tube and a soldered or brazed joint may replace the cold weld or force fit.