GB570991A - Improvements relating to apparatus for electric resistance welding - Google Patents

Abstract

570,991. Welding bellows &c. tubes to couplings &c. EVERY, C. E. (Chicago Metal Hose Corporation). July 19, 1943, No. 11744. [Classes 83 (ii) and 83 (iv)] In electric resistance, seam welding circular workpieces, such as stainless steel, corrugated tubing or bellows, to other tubes or to coupling members or end fittings by a pair of rotatable electrodes, one of the electrodes is arranged within the workpiece and the other is of annular form and is adapted to encircle the workpiece. In welding workpieces of different thicknesses, the contact areas of the electrodes are proportional to the thicknesses of the respective parts. The inner electrode 23 is mounted between removable flanges 52, 53 on a body 50 screwed into a shaft 22 which is rotated by bevel gear 33, 32 from a shaft driven through a pedal-operated clutch by a belt 27 from an electric motor 25. The electrode roller 18 which has a removable rim 37 and an axle 36 of large diameter is carried in a forked member 17 vertically adjustable by a rack and pinion. The shaft 22 has a centred passage for cooling water which passes through radial ducts 56, 57 so that it is sprayed on to both sides of the inner electrode and against the interior surface of the work. The upper electrode and the outer surface of the work are cooled by liquid from spray nozzles 61, 62. The work 15 which passes through the bracket 13, is supported on the electrode 23 and on a vertically adjustable platform 16. The electrode body 50 is supported by a fixed shaft 65 which is adjustable in a support block 66. The electrode roller 18, which is of greater diameter than electrode 23, engages the work through a V-grooved ring electrode 40 of large diameter, which encircles' the workpieces and the contact width and contact arc of which are greater than that of the electrode 23 to suit the different thickness of the tube 15 with respect to the coupling 41 to which it is welded so as to obtain maximum current intensity without damage to the thinner part. In a modification, Fig. 4, the upper electrode may consist of an annulus 37b, secured to a body 80 which is rotated in ball bearings 82 by gearing 84, 85. Current may be conducted to the electrode through a mercury bath 86.