Patent GB-1347527-A (GB)
Title: Apparatus for conducting gas and electrical current
IPC: H01B9/00
Filed: 1971-04-19
Abstract: 1347527 Welding and cutting by fusion COORDINATED INDUSTRIES Inc 19 April 1971 [11 Feb 1970] 20997/71 Headings B3R and B3V [Also in Division H2] A readily disconnectible shielding gas (e.g. argon or helium) and current transmission connection device between a flexible cable/hose 1 and a connectible member, e.g. for use in cutting or, as shown, consumable electrode arc welding, comprises a recessed member 22 secured to the cable/hose and a co-operating spigot 52 connected to the connectible member, a spherically ended screw 42 in the member 22 being provided for engagement with a circumferential groove 54 of the spigot 52 to prevent disconnecting relative axial movement of the recessed member and spigot whilst allowing relative rotation thereof. As shown, the connectible member is the curved barrel 3 of a consumable electrode arc welding gun, the connection device also transmitting electrode wire. The member 22 and the barrel 3 are of electrically conducting metal such as aluminium, brass, copper. The recess of the member 22 and the spigot 52 are preferably frusto-conical. The cable/hose comprises an inner sheath 13 preferably of non- magnetic and electrically non-conductive material, e.g. natural or synthetic rubber or plastics, an intermediate welding current carrying sheath 14 of strands, e.g. of copper, and an outer sheath 16 of non-magnetic, electrically non-conductive material, e.g. natural or synthetic rubber or plastics. As shown, a further sheath 17 is loosely slipped over the sheath 16 and encloses current and wire feed control conductors 8, 9. A removable, wire passage, tube 18, of flexible non-magnetic, non-conductive synthetic material, such as nylon, or of non-magnetic stainless steel, is enclosed by the cable/hose, an annular space between the tube 18 and the sheath 13 providing a gas passage. The cable/hose is secured to the member 22 by being clamped between a spigot 25 of the member and a sleeve nut 29 threaded thereon, the outer sheath 16 being cut back so that the sleeve nut can make electrical connection with the sheath 14, and the spigot 25 and a sleeve nut 29 being provided with cable/hose gripping projections such as screw threads. Internal ribs 40a of the recessed member 22 support the tube 18. An electrically insulating handle 45, e.g. of hard synthetic plastics, is clamped on to the cable/hose end by screws 46, and carries a trigger 47 by which a switch 48 connected to the conductors 8, 9 is actuated. The barrel 3 and cable/hose are held in a selected one of several relative rotational positions by a disengageable detent 49 which is provided on the handle and is engageable in one of exterior grooves on the barrel. The latter comprises a circular or, preferably, elliptical cross-section body 51 which is extended to form the spigot 52. The body 51 has external longitudinal ribs (56) engaging a surrounding, heat resistant, electrically insulating, e.g. silicone rubber, sheath 61, the resulting longitudinal channels between the body and sheath providing air cooling passages, and has internal longitudinal ribs (63) engaging a wire passage tube 65, e.g. of stainless steel, the resulting longitudinal channels between the tube body providing shielding gas passages and the ribs (63) providing heat transfer surfaces over which the shielding gas coolingly flows. At the exit end, the tube 65 has gas admitting slots 67 providing resiliently outwardly biased fingers 68, and the ribs (63) are cut back inside the barrel to provide a recess 71. A contact tube 72, e.g. of copper, is pushed into the recess 71 and held by the fingers 68. A gas nozzle 85, e.g. of copper, is held by a spring retaining ring 84 on a heat resistant, electrically insulating, e.g. thermoset phenolic resin, bushing 80 threaded on to the exit end of the body 51. Shielding gas enters the nozzle 85 through holes 78 in the contact tube. The end of the cable/hose remote from the gun has a second recessed member 22 secured thereto, the arrangement being such that to equalize wear the cable may be turned end-to-end. A shielding gas supply hose 5 is connected to a pipe 87 secured to the member 22 and communicating with the inner bore 40 thereof. A welding current supply wire 6 is connected to the member 22 via a bracket 86. A lined electrode wire feed member 88 is inserted into the member 22 and retained by a screw 90. An apertured washer 92, preferably of felt, and, if desired, an apertured washer 93, e.g. of rubber, are disposed between the members 22, 88 to wipe dirt and dust from the electrode wire and to prevent gas leakage. Reference has been directed by the Comptroller to Specification 1,015,256.