GB827044A - Improvements in or relating to welding guns - Google Patents

Abstract

827,044. Welding by fusion. REVERE COPPER & BRASS Inc. Nov. 28, 1957 [Aug. 15, 1957], No. 37188/57. Class 83 (4). [Also in Group XI] An arc welding gun is adapted to make an internal weld between a tube 7 and one side of an apertured plate 5 while positioned on the other side of the plate. The gun consists of a handle 25 with a trigger switch 29 attached to a cylindrical casing 23 which in use is pressed against the plate 5. Rotatably mounted on anti-friction bearings 33 within the casing 23 is a housing 35 carrying an insulating block 45 and having a portion 81 of reduced diameter carrying a collar 83 adapted to fit within an aperture in the plate 5 to locate the gun. A non-consumable electrode 17 is clamped by a rod 73 having a threaded end in a tube 51 mounted in and adjustable longitudinally of the block 45. A conductive sleeve 57 on the tube 51 rotatably holds a conductive block 89 and a pipe 117 is brazed in a groove in the sleeve. Cooling water is passed through the pipe 117 which also serves to conduct welding current from a cable 127. Shielding gas is supplied from a pipe 95 through passages and annular grooves to a space between the rod 73 and the tube 51 and escapes through holes 107 in the tube 51 and an aperture 87 surrounding the electrode. The electrode 17 and block 45 are rotated by a worm-wheel 37 secured on the housing 35 and driven by a worm and flexible shaft drive, the gas and water pipes and the block 89 remaining stationary. The welding is automatically controlled in response to the trigger switch 29 by the control system described in Specification 824,586. The sheet 5 is formed with annular projections 11 prepared as shown in Fig. 11 for the welding operation.