Patent GB-681889-A (GB)
Title: Improvements in or relating to electric welding devices by means of a consumable electrode wire
IPC: B23K9/29
Filed: 1951-04-17
Abstract: 681,889. Uniting by fusion. UNIONMELT SOC. ANON. April 17, 1951 [April 18,1950; March 29, 1951], No. 8971/51. Class 83 (iv). An electric welding device comprising a bare electrode wire which is fed towards the part to be welded through a flexible hose and a welding head is characterized in that the flexible hose constitutes a conductor bringing the welding current to the head. The electrode wire 1 which may be fed by rollers (not shown) is guided inside a flexible hose 4 situated between the feed rollers and a welding head 3. The flexible hose comprises an electric conductor 5 of copper or other metal, having an external insulating coating 6 made of rubber and cloth and an inner coating comprising a flexible metal hose 7 within which is slidably located a sheath 8 of spring bronze wire, the turns of which are joined together, the said metal hose 7 being firmly retained within the conductor 5. One end of the conductor 5 is secured in a socket 9 on a lug 10 (Fig. 4) and the other end to a part 11, inside the head 3, which has a reduced front portion 12 through which the sheath 8 slides freely and a ring 13 welded on the end of the sheath 8 abuts the portion 12 and prevents backward motion of the sheath 8. Forward motion of the sheath is prevented by the ring 13 abutting a shoulder 15 provided with a support 16 of a welding nozzle 17. The welding circuit is insulated from the nozzle 17 and the head 3 by insulating washers 18 and 19 and an insulating tube 34 which covers the part 11. The head 3 contains a chamber 20 for a welding powder which is delivered to the weld by a conduit 21 controlled by a manuallyoperated stopper 22. The powder is supplied to the chamber 20 by compressed air through a flexible hose 25, the compressed air escaping through a metal gauze 27 in the top of the chamber. In its open position the stopper 22 partly closes an aperture 30 through which the powder is supplied, thus regulating the supply and preventing agglomeration of powder from entering the chamber. The feed of the electrode wire 1 is controlled by an electric switch 32 connected to a two-wire cable, 33. In an embodiment the stopper 36 (Fig. 6) is provided, over its entire width, with an aperture 37 so that when in the opening position the upper portion 38 of the stopper prevents the powder from being ejected through the gauze 27. The web 39 which connects the upper and lower portions of the stopper and the hub 40 assist in breaking up powder clots brought by the compressed air. In another embodiment the welding powder is contained in a hopper 41 (Fig. 8) placed above the chamber 20. In a further embodiment the head 44 (Fig. 9) is formed from a bent metal tube carrying a nozzle 45 at one end, the other end being screwed into a socket 46 welded on the end of the flexible electrical conductor 47 which is externally and internally coated as hitherto. At the end of the conductor where the electrode wire is introduced a small tube 56 is inserted inside the sheath 52. The tube 56 has a flaring 57 bearing against a shoulder 58 in a socket lug 72 into which is screwed a hollow plug 59. An insulating handle 60 covers the front end of the flexible cable and the rear portion of the head 44. The welding powder is delivered from a funnel 63 secured to the head by a strap 62. A stopper 65 controlled by a handle 66 controls the flow of powder. Welding powder may be delivered continuously to the funnel by compressed air from a delivery tube inserted in the hole shown closed by a stopper 68. An inert gas may be delivered to the weld through the annular cavity surrounding the electrode wire.