GB271501A - Improvements in or relating to automatic welding machines - Google Patents

Abstract

271,501. British Thomson-Houston Co., Ltd., (Assignees of Chapman, V. J.). May 22, 1926, [Convention date]. Uniting by fusion.-In fusion welding by an electric arc or gas torch in which the work and source of heat are moved relatively to one another and in which the source of heat is oscillated across the joint, the source of heat is moved relatively slowly across the centre of the line of the joint and relatively rapidly at points distant from the centre line e.g. as shown at 44, Fig. 5, in order to increase the penetration of the work and prevent the formation of a weld concave at the centre and piled up at the edges. A metallic electrode 1 is fed through guide tubes 9, 10, terminal block 11 and contact nozzle 12 on a head 4 carried by a standard 5 which is mounted on a carriage 6 traversed with relation to the seam 3 to be welded. The electrode is fed by rolls rotated by change speed gearing from a motor 7. The welding head is adjustable laterally of the seam by a hand wheel 13 and the pressure of the rolls is adjusted by a hand wheel 14. The tube 10 is pivoted at 15 and is connected by a link 20 and adjustable clamps 18, 19 to a rod 21 to which a shaft 23 is secured by an adjustable clamp 22. The shaft is mounted in an elongated bearing tube 24 carried by the head and has a slotted upper end in which is pinned an arm 25 provided with a strip of insulating material 30 carrying a cam follower 32. This follower, which has an oil cup 33, co-operates with and lubricates a cam 34 on the shaft of one of the feed rolls, so as to oscillate the electrode across the joint, the follower being held in contact with the cam by an adjustable spring 36. To vary the amplitude of the oscillations, the set-screws securing the clamps 18, 19, 22 are released and the clamps adjusted with respect to the shaft 23 and tube 10.