GB836084A - Improvements in or relating to electric welding - Google Patents

Abstract

836,084. Welding by fusion. WESTING- HOUSE ELECTRIC CORPORATION. March 10, 1958 [March 19, 1957], No. 7588/58. Class 83 (4). A tube 23 is welded to a plate 21 by providing a shoulder 151 on the plate 21 around the tube, and welding with a non-consumable electrode moved around the axis of the tube. A mandrel 31, e.g. of copper, having resilient limbs 59 fits within the tube 23 with a locating shoulder 65 engaging the end of the tube. An insulating sleeve 81 of, e.g. synthetic resin, with a steel liner 85 is rotatably mounted on the upper end of the mandrel 31 and carries a socket 95 receiving a flexible shaft 47 connected to a motor 45. The sleeve 81 is integrally formed with a clamp 83 having an aperture 101 in which is held an adaptor 121, e.g. of brass. An electrode holder 141 is provided with a threaded projection 165 secured in an aperture 127 at one end of the adaptor 121. The holder 141 carries a collet 41 for holding the electrode 39 and a nozzle 43 to which shielding gas is passed through a passage 131 in the adaptor. The welding is automatically controlled. The electrode is rotated for more than a complete revolution and, at the end, the welding current is gradually decreased to prevent cratering. Before welding the electrode is correctly positioned by the use of gauges. A second pass can be made to fuse a filler ring 173 into the weld.