Patent GB-657360-A (GB)
Title: Improvements in or relating to hollow electrodes for arc welding or oxy-arc cutting
IPC: B23K35/02
Filed: 1949-02-04
Abstract: 657,360. Uniting and dividing by fusion. WELDING SUPPLIES Ltd. Feb. 4, 1949, No. 3200. Convention date, July 3, 1948. [A Specification was laid open to inspection under Sect. 91 of the Acts on Aug. 8, 1949.] [Class 83 (iv)] An electrode for arc welding or oxy-arc cutting comprises at least four core wires 1-4, Figs. 1 and 2, disposed so as to form a central channel 5 and having a common exterior coating of flux 6. The core wires 1-4 are held together at one end by ligatures 8 and at the other by a metallic sleeve 7 which also conducts gas and electric current to the channel from an electrode holder (not shown). Intermediate ligatures 8 may be provided. When assembling the electrode the core wires are arranged around an auxiliary wire of cross-section corresponding to that of the channel 5 and then gripped by the sleeve 7 and ligatures 8. The coating 6 is then applied by dipping and extends beyond the lower edge of the sleeve 7 to provide a gas-tight joint. Finally, the coating is dried and the auxiliary wire removed. The Specification as open to inspection under Sect. 91 discloses an electrode comprising a metal core 2 (Fig. 1, Cancelled), provided with a longitudinal groove 3 which is covered by a metal strip 4 to form a gas conduit 1, the electrode then being coated with a flux 7 and having a sleeve 5 as hitherto described. In a modification the core wire is of circular cross-section and a U-shaped metal strip is welded to the wire to form the conduit. In an electrode intended for under-water use the core wire has a longitudinal groove and is covered by an electrically insulating sleeve 6 (Fig. 4, Cancelled), e.g. impregnated paper, which is coated with flux 14 and then with an exterior insulating lacquer coating 15. In a further modification the gas conduit 16 (Fig. 6, Cancelled), is formed partly by a groove 17 in the core 18 and partly by the flux coating 19. The sleeve 20 has, in its lower portion an internal diameter greater than the core diameter so forming an annular chamber 23 which avoids a restriction in the inlet of the gas conduit 16. The upper end of the core has two diametrical slots 22 at right angles to each other which serve to conduct gas from the inlet 21 to the annular chamber 23. In another modification the core 24 (Fig. 10 Cancelled), is circular in cross-section and the gas conduit 25 is confined within the flux coating 26. The lower portion of the sleeve 27 is flared to form an inlet chamber 29 for the gas conduit 25 and a slanting bore 28 in the core connects the gas inlet with the chamber 29. In a further modification the electrode has two gas conduits diametrically opposite to one another each being formed by a longitudinal groove in the core and a corresponding groove in the flux coating. The lower part of the connecting sleeve is flared and the upper part of the core is provided with a slot. In another embodiment the core 37 (Fig. 15 Cancelled), which is of circular cross-section has a part limited by a plane cut-away surface 371 and a U-shaped metal strip 38 is welded to the plane surface. The sleeve 39 embraces the upper part of the core 37 and the strip 38. In a further embodiment the gas conduit is formed by a tube which fits into a longitudinal recess in the core and is embedded within the flux coating. The upper end of the tube extends above the upper end of the core and is connected to the source of gas. The tube may consist of metal strip bent into shape, or glass or organic material such as paper or artificial resin. The core may be of rectangular crosssection and the tube placed at one side of the core or the tube may be placed between two rectangular cores. This subject-matter does not appear in the Specification as accepted.