GB1036805A - Improvements in or relating to apparatus for welding circular joints - Google Patents

Abstract

1,036,805. Welding by fusion. ESAB Ltd. Dec. 17, 1964, [Dec. 21, 1963], No. 51431/64 Heading B3R. In. gas-shielded metal arc welding apparatus for welding circular joints, e.g. tubes to tube plates, comprising a head unit to which shielding gas and welding current are supplied through flexible connections and a torch unit rotatably attached to the head unit, the head unit comprises a motor for rotating the torch unit and an electrode wire feed mechanism, and the torch unit comprises a substantially straight tubular body 14, Figs. 1 and 2 (not shown), coaxial with its axis of rotation relative to the head unit, a concentric electrode wire guide tube 19, the space between the body 14 and the tube 19 forming a shielding gas passage, a holding device 25 attached externally of the body 14 and a centring member 24 journalled in the holding device 25 and adapted to engage the work concentrically of the joint to be welded. The guide tube 19 is rotatable within and is supplied with current by a spring collet 11 in the head unit and terminates in a contact member 23 having an inclined surface deflecting the wire inwardly towards the centring member 24. Air motors in handles 3, 33 respectively rotate the torch unit and drive wire feed rollers. A gas nozzle 22 having an asymmetrically shaped end is held in spring fingers 21 terminating the body 14. The holding device 25 is pivoted to a clamp 26 and is connected by pivoted links to a clamp 30. By adjustment of the clamps 26, 30 on the body 14, the distance of the contact member 23 from the work and the radius of rotation can be determined. The body 14 and guide tube 19 may be interchanged with others of differing lengths.