GB712259A - Improvements in electric welding apparatus - Google Patents

Abstract

712,259. Uniting by fusion. AIR REDUCTION CO., Inc. Nov. 23, 1951 [Feb. 5, 1951], No. 27543/51. Class 83 (4) In a gas shielded metal arc welding apparatus comprising a gun with an electrode wire guide within a shielding gas assembly and a flexible casing for conducting electrode wire to the gun, wire engaging non-galling electrically non- conducting liners are provided in the casing and the guide. In an embodiment a portable gun has a copper nozzle 4, Fig. 1, at one end of an insulating barrel 1. A contact tube 14 within the nozzle 4 is screwed to a toothed member 20 for ensuring correct gas flow which is soldered to a metal barrel member 19. The member 19 is connected by a stud 8 to the welding current supply through a trigger switch 12. An insulating sleeve 7 is provided within the member 19 and the electrode wire 21 is fed through this to the contact tube 14. The wire 21 is fed from a remote roller feed 27, Fig. 3, through an insulating sleeve 30 in a shielding gas supply fitting 32 into a nylon liner 38 surrounded by a flexible metal tube 35. The tube 35 is soldered into a fitting 36 and the liner 38 is held fixed therein, the fitting 36 being clamped to the fitting 32 by a nut 34. A flexible hose 45 is fastened to the fitting 36 around the tube 35 and shielding gas is fed into the space 46 between the tube 35 and the hose 45 from an inlet 28 and through holes 36<SP>1</SP> in the fitting 36. The other end of the tube 35 is soldered to a fitting 37 screwed into the gun. The liner 38 passes through the fitting 37 with clearance into the gun and is not secured at this end so that its expansion may be allowed. Slots 48 in the fitting 37 allow the shielding gas to pass around the liner 38 into the gun to flow about the member 19, through the toothed member 20 and out of the nozzle 4. The insulating members 7, 30 may be of nylon or other described plastics. Chemically clean electrode wires of aluminium or magnesium may be used in the apparatus. Specifications 687,666 and 712,238 are referred to.