GB1268185A - Method of spot welding and an electrode for use in the method - Google Patents

Abstract

1,268,185. Welding by pressure. BURNLEY ENG., PRODUCTS Ltd. 14 April, 1969 [23 April, 1968], No. 19059/68. Heading B3R. In resistance spot welding two members which do not conform sufficiently for satisfactory welding between conventional rigid electrodes, an electrode in pliable condition is employed. A metal honeycomb seal 10 Fig. 1 is applied to a metallic ring 11, an electrode 22 is applied to the ring 11 remote from the honeycomb seal and an electrode 14 is applied to the seal, the electrode 14 comprising a metallic holder 15 containing a number of copper strands 16. The strands 16 deform under pressure and flatten high spots on the seal without damage thereto and welds are made between the faces of the cells of the seal and the ring 11. A similar deformable electrode may also be applied to a backing ring having an irregular face remote from the honeycomb seal. In a modification a braided strip or sheet of electrically conductive metal or a braided copper tape may be employed to engage the honeycomb seal and is pressed by a relatively non-deformable electrode. In a further embodiment the deformable electrode comprises a braided copper sheet 33 Fig. 7 or thin copper sheet mounted on a hollow fluid impermeable backing 74, e.g. of leather or thermoplastics, containing a pressure medium e.g. air, water or oil. The ends of the sheet are secured to a metal holder 37 through which current is supplied and pressure applied. The deformable electrode of Fig. 7 may be used possibly with a similar electrode to weld a metallic honeycomb core between two metallic sheets to form an acoustic panel having e.g. a double curvature. Spot welds are produced by the apparatus of the invention at closely spaced positions. If a honeycomb seal has its cells at an angle to the surface it engages, that surface may be knurled or grooved to prevent slipping under electrode pressure.