Patent GB-173859-A (GB)
Title: Improvements in and relating to electric welding apparatus
IPC: B23K9/073
Filed: 1920-10-07
Abstract: 173,859. British Thomson - Houston Co., Ltd., (General Electric Co.). Oct. 7, 1920. Drviiing by fusion.-In an - electric-arc welding-machine of the type in which the electrode is continuously fed at an automatically 'v regulated speed to maintain the are of constant length, the welding-head is carried by an arm, which is movable about horizontal and vertical axes on a support, which carries driving-gear for feeding the electrode. The welding- head 1 is secured to an arm 2 pivoted on a shaft 6 in a part 3, which is adjustable about a vertical axis in a support 4 forming part of a slide; this is vertically adjustable on a frame 10 by a rack and pinion through a hand-wheel 12 and is counterbalanced by a weight 100. The arm 2 is partly balanced by an adjustable weight 7. The frame 10 is adjusted by a screw 13 on a bracket 11' which is secured to the base 12' and also to a post 14 to prevent the tendency of the welding head to tip the machine over. The electrode wire is led from a reel 37 over rolls 38 on a curved guide 39 carried by a support 39' to a pair of feed-rolls 15, 16 on the welding-head. The feed-rolls are driven from a motor 28 on the slide 4 through spur gear 29, 30, worm gear 31, 32, change-speed gear 34', bevel-gear 35 27, 23, 24, 23, 22 and spur gear 20, 19, so that the drive is effective in any adjusted position and during adjustment. The feed may be started by a hand-wheel 62. The ,electrode tip may be oscillated across the seam during welding to produce wide welds. In the form shown in Fig. 3, the electrode passes through a hole in a lever 46 which is oscillated bv a cam 57 through a lever 58 and spring-controlled link 59. In a modification, Fig. 4, the oscillation is effected by a lever 46' in a plane at right-angles to that shown in Fig. 3 by a cam 57' through lever 58' and link 59', the lever 46' and base 61 having a series of holes to receive the pivot pin 56' to vary the amplitude of the oscillations. The welding-head has a number of heat-radiating plates 47. In order that the length of the arc may remain constant when welding irregular seams while maintaining the length of electrode projecting from the welding-head constant, the welding-head is provided with a tracker roller 48 engaging the seam so that it mav rise and fall in accordance with the irregularities in the seam. In case a series of similar articles is to be welded in succession, the roller 48 may engage a templet. The work 49 is traversed under the welding-head by rollers 52, 51 on shafts at right-angles, which are rotated by worm gear 53, 54, 55 and spur gear from a motor 54<1>. One terminal of the circuit is connected by a brush bearing to one of the feed-rolls and the other to the work-conveyer, the welding-head being insulated from the work conveyer by insulation between the head and arm and by making one of the gears 19, 20 of fibre. The automatic guiding by the tracker roller may be dispensed with, the welding-head being manually adjusted and clamped in any desired position. Specifications 139,919 and 145,330 are referred to.