GB954006A - Welding metal portions of finite length by high frequency heating - Google Patents

Abstract

954,006. Making hollow-ware; welding by pressure. AMERICAN MACHINE & FOUNDRY CO. Feb. 28, 1963 [March 6, 1962], No. 8129/63. Headings B3A and B3R. In welding throughout their effective lengths the opposed adjacent edges of a pair of metal portions of finite length, the portions are advanced with other conductive elements preceding and succeeding same in alignment and in contact therewith the edges are pressed into welding relation at a weld point, a first contact means is provided to engage the assembly at or adjacent the line of the desired weld seam and at a region in advance of the weld point, a second contact means is provided to engage the assembly at or adjacent the line of the desired seam and at the region of the weld point and current of at least 50 kc. per sec. is supplied to the contact means to provide parallel flows of current along the edges between the contact means, the preceding conductive element or elements in passing the weld point serving to provide paths for the current before the metal portions reach the weld point and the succeeding conductive element or elements serving to maintain current paths after the edges have passed the first contact means. A succession of short gapped tubes 10, Fig. 1, are advanced with each pressing against the next by caterpillar belt means 13, 14, the gaps are held aligned by a guide 15 and rollers 17, 18 driven at a lower speed than the means 13, 14 bring the edges together. Current of a frequency of 50-500 kc. per sec. is supplied from a source 19 to contact means 20 in advance of the weld point w and to contact means 21 at the weld point, the contact members each comprising one or a pair of spring like contacts. A conductor 22 extends along the seam line between the contacts to concentrate the current flow. In a modification an individual workpiece 30, Fig. 2, to be welded has ring like detachable slotted elements 32, 33 at its front and rear ends, the elements having flanged ends embraced by the workpiece. If the workpiece is of magnetic metal the elements may be of non-magnetic metal e.g. copper or phosphor bronze. Edges of portions may be preheated by furnace or internal and/or external induction means and the portions may be fluid tank bodies, wheel rims or hoops or strip lengths may be welded. Specifications 851,528, 851,530, 869,336, 869,337 and 869,938 are referred to.