GB1460901A - Orbital welding apparatus - Google Patents

Abstract

1460901 Welding by fusion CLARKE CHAPMAN Ltd 19 April 1974 [10 May 1973] 22268/73 Heading B3R A MIG, MAG or, as shown, TIG orbital welder, for tube/tube or tube/plate welding, comprises first and second members relatively rotatable about a common axis, the first member presenting a cylindrical drive surface coaxial with said common axis and the second member being rotatable and carrying one or more V- grooved rollers and an electrode or filler wire guide, each roller co-operating with said drive surface to define a wire driving nip and the wire guide having an entrance positioned to sweep past said drive surface. The fed wire may be heated by electrical resistance. As shown, for tube/tube welding, the first and second members comprise diametrically split worm-wheels 18, 26 rotatably mounted in a diametrically split (e.g. hinged) housing 10 and meshing independently drivable worms 16, 14. The cylindrical drive surface, 20, is formed on the worm-wheel 18. The worm-wheel 26 carries, via blocks 32, 50 main and auxiliary wire guide tubes 30, 60, the tube 30 extending towards a TIG torch 70 also carried by the worm-wheel 26. Rollers 36, 38, 40 and links 52, 42, 44, 46 form a chain which is supported by the blocks 32, 50 and is adjustably tensioned, by a device 54, to urge the rollers inwardly towards the drive surface 20. To effect feeding of wire 82, from a spool (not shown), the worm-wheel 18 is rotated slower than or in an opposite direction to the worm-sheel 26. If wire feed speed control is not required, the drive surface 20 may be formed directly on the stationary housing 10, the worm-wheel 18 being dispensed with. In Fig. 3 (not shown) the cylindrical drive surface is an internal surface of the first member worm-wheel, and two or more rollers carried by the second member worm-wheel are included in a chain which is adjustably compressed to urge the rollers outwardly towards the drive surface. The wire may be stored on a spool carried by the second member worm-wheel or within the latter in which case the wire is retained by its own tendency to spring outwardly and, if necessary, by an inwardly directed flange of said wormwheel.