GB1468533A - Explosively welded electric conductor - Google Patents

Abstract

1468533 Making electrical connectors; welding by pressure GEORG FISCHER AG 27 March 1974 [6 April 1973 4 March 1974] 13539/74 Headings B3A and B3R In making an electric conductor a plurality of conductive metal sheets are arranged in a stack, at least one explosive charge is placed at each end of the stack, spacers are inserted between the sheets in the region between the charges at the ends of the stack and the charges are detonated to weld the sheets at each end of the stack. A conductor for use with a rigid conductor, e.g. a busbar or tubular cable, to compensate for the thermal expansion of the rigid member is produced by stacking aluminium or copper sheets 14 Fig. 2 with shorter intermediate spacer strips 16 of steel or plastics material and of unequal length. The ends of the sheets 14 are separated by spacers which together form a comb of steel or plastics material and the assembly is introduced into a two part tool 41, 51 wherein a fold is produced and maintained. Resilient inserts e.g. of rubber or plastics material are provided in the region of the positions 20 and explosive charges 44 are located at the ends of the sheet, 14, and with bodies of metal or plastics material pressed against the sides of the stack where welding is to occur the charges are detonated to produce a conductor 22 as shown in Fig. 3. The explosive charges may be arranged on only one side of the sheets when separating layers of oil, rubber or plastics material are placed between the tools and the sheets and the fold may be formed after welding when the tool 41, 51 may not be required. After welding the spacers 16 are removed the welded ends are squeezed in a press which may have fine transverse grooves to assist current transmission and undesirable parts may be removed and/or fastening holes may be produced. In a modification a three layer conductor is similarly produced with the unwelded parts of the strips spaced apart for cooling purposes. In a further modification a stack of aluminium sheets 48 Fig. 6 is formed with transposed plastics material spacers 49 between the parts of the sheets which are not to be welded and with spacers 52 of spring steel between the ends of the sheets which are to be welded. The stack is clamped between steel tools 41, 51 with interposed plastics layers 46 and explosive charges 44 are arranged at the ends of the stack. Before detonation the spacers 52 are removed and spacing bridges of plaster of paris are provided instead. After detonation of the charges and removal of the tools 41, 51 the welded sheets are cut into a number of strip like conductors by a plurality of circular or band sands in one pass, the welded ends are pressed with grooved tools and holes are punched into the ends. The spacers 49 are finally removed.