GB1142922A - Longitudinal strip edge butt welding - Google Patents

Abstract

1,142,922. Welding. THOMSON CORP. 9 May, 1967, No. 21573/67. Heading B3B. Metal strips 16, 18 are butt welded by moving the strips at a relative acute angle, up to a welding head 28, providing a high frequency electric current, whereupon the edges of the strip are heated when spaced apart, whilst being held in slightly overlapped relationship, and then moved transversely, so that they wipe across each other and are welded. The apparatus 10 for carrying out the operation comprises a base 20, adjustable guide rolls 22, strip tensioning rolls 26, welding head 28, edge forging rolls 34, 36, compression rolls 46, 48, pinch rolls 50, 52, and where one of the strips is of zinc-coated steel, means for supplying carbon dioxide, or nitrogen to the welding area. Rolls 34, 36 are supported in fixtures 38, 40, and are held against the strips by a pneumatic cylinder 42. The strips may be galvanized cold rolled steel, stainless steel, or non-ferrous metal, and they may be of the same, or different materials. Guide roll stands 24 are insulated at 56, rolls 26 are made of polyurethane, and rolls 34, 36 are of bronze, brass, or ceramics. Rests 64 are provided for the strips and are adjustable about pivots 66 so as to vary the approach angle between the strips. Electrodes 80 are secured to arm 82 pivotable at 84, and engage the top faces of the strips. Rolls 46, 48 are disposed slightly rearwardly of rolls 34, 36 and are held in contact with the composite strip by springs 100, whose rating can be adjustable. In operation, strips 16, 18 are taken from reels insulated from each other, are guided by rolls 22, tensioned by rolls 26, heated to a plastic state by electrodes 80, squeezed by rolls 34, 36, followed by rolls 46, 48, and then the composite strip is removed by rolls 50, 52 to a wind-up reel.