GB564231A - Improvements in electric welding - Google Patents

Abstract

564,231. Making chains &c. LINDE AIR PRODUCTS CO. May 22, 1943, No. 8158. Convention date, May 22, 1942. [Classes 83 (i), 83 (ii) and 83 (iv)] Uniting by fusion; casting.-Chain links, bars, rods and like ferrous articles are electrically welded by enclosing the parts at the joint in heat conducting separable moulds co-operating to form a work-receiving recess conforming to the work, placing unbonded granular fusible mineral welding material in the recess and between the parts of the joint, inserting a metal weld rod and passing an electric current through the rod, material and work to melt metal from the rod and at least a part of the mineral material so that the molten metal coalesces with the melted portion of the work. Chains may thus be welded without altering the overall dimensions thereof in contradistinction to a forged or resistance weld and may be made from corrosion resisting or high tensile steels. The mould may consist of a pair of rectangular copper blocks M, M<1>, formed on their front faces with grooves 14, 141 to receive one of the links L of the chain, the ends of the links of which are bevelled and in contact with each other so as to form a welding groove 60. Intersecting the grooves 14, 14<1> in the blocks at their upper edge and central of the blocks are recesses 16 with sloping rear and side walls to form a hopper through which the granular welding material G is introduced. Passages 30 for cooling fluid extend through the blocks parallel to the grooves and are provided with inlet and outlet conduits. 'The welding metal is provided by an electrode R inserted into the welding material with its lower end in operative relation to the extremities of the link and an electric current is then passed therethrough to the link. The fused welding material G by the circulation of cooling fluid through the blocks solidifies as a thin film on the walls of the recess 50 to form a heat insulating layer so that the molten metal will fill the space between the ends of the link to the contour of the recess. In another form, particularly for welding a stud link chain, the mould blocks, which are provided with a lap joint, are separated by apertured gaskets W from blocks B, B<1> to which they are bolted and which are secured to links 102, 104 provided with studs 106 mounted on a pivot 108 and connected by links 124, 128 to a crank 114, which is pivoted at 116. The arm 126 is connected to the piston P of a pivotally mounted cylinder A and a lost-motion connection between the links 124 and 102 is provided. The mould blocks are cooled by fluid circulated through passages 94, 88. The mould blocks have in addition to the matching grooves 74 to receive the ends of the link, matching grooves 82 to receive the stud S. The welding circuit is completed by studs 132 carried by the links 102, 104 and engaging the link L.