GB1319239A - Automatic arc-welding torches - Google Patents

Abstract

1319239 Welding by fusion FOSTER WHEELER JOHN BROWN BOILERS Ltd 11 Sept 1970 [22 Sept 1969] 46635/69 Heading B3R A TIG welding apparatus for butt-welding tubes (16), (18) end-to-end comprises a split annular support 12 attachable to one of the tubes and a split annular table 14 supported by, and rotatable with respect to, the support 12, the table carrying a TIG head 32 and filler wire supply means comprising a supply reel 58, feed rollers 60 and a guide tube 56. The table is rotated by a motor 30 and the feed rollers are driven, when desired, by a drive derived from the table rotation. The table drive comprises a table mounted motor and reduction gear-box 30 having a drive pinion (26) meshing an annular rack 24 carried by the support. For manual adjustment of the table the pinion 26 may be disengaged. The feed roller drive is by gearing 74 providing two speeds and neutral (for slow, fast and no wire feed) and comprises an input pinion 70 meshing the rack 24 and driving a shaft 72 to which is co-rotatably but slidably connected an axially movable shaft 76. Gears 78, 80 free on the shaft 72, 76 mesh pinions 88, 90 fast with a feed roller shaft 61 geared to a further feed roller shaft 62. A clutch member 82, shown in a central neutral position, is movable into engagement with either of the gears 78, 80 by a stepping motor 94 acting on the shaft 76 via a cam 98. The head 32 and filler wire guide tube 56 are oscillatable, being mounted on a hinged platform 40 having a slot 46 engaged by a crank-pin 48 driven by an electric quarterturn stepping motor 52. Example V-preparation weld steps comprise a first, root, run (normally made without filler wire, i.e. with the gearing in neutral), a second run with the gearing set for slow filler speed, and a third run with the gearing set for fast filler speed. Increased feed rate may be obtained by using a larger diameter filler wire. The head 52 may be oscillated for the final one or more runs.