GB915209A - Improvements in or relating to welding electrode arrangements - Google Patents

Abstract

915,209. Welding by pressure. GENERAL ELECTRIC CO. Ltd. May 26, 1961 [May 30, 1960], No. 19036/60. Class 83 (4). A welding electrode arrangement for tubes, rings, caps and like annular workpieces 40, Fig. 1, comprises a mandrel 1 carrying or forming a first electrode arranged to extend within the workpiece, and a second electrode 8 which is of annular form, arranged to encircle the workpiece, and have an internal work-engaging face to co-operate with the first electrode, the electrodes being rotatable one relative to the other so that during a welding operation different circumferential parts of the workpiece pass between co-operating portions of the electrodes. As described, the workpiece consists of a cap 40 which is to be welded into the end of a tube 38, the tube being clamped by a ring 31 of rubber which is disposed in a cylinder 32 and compressed on to the tube by a sleeve 33 connected to a handle 34. The sleeve 33 and cylinders 32 are connected by gears 36, a rod 27 and gears 28 to a member 25 carrying the electrode 1 and rotatable in a bush 26 by a motor 23. The second electrode 8 is secured to a bush 6 rotatably mounted in bearings 7 in a housing 5 of a welding head 2 secured to a column 3 movable vertically by hydraulic or pneumatic means to bring the internal surface of the electrode 8 into engagement with the workpiece ; the electrode is adjustable axially of the workpiece by means of a slide 21. Current is supplied to the electrode 8 from a contact 16 spring-urged into engagement with the bush 6 which is insulated from the head by insulating members 13. During welding, the motor 23 rotates the electrode 1 and the workpiece 38, the electrode 8 being pressed against the workpiece so as to rotate by frictional engagement therewith. Cooling water may be supplied to the contact 26 and electrode 8. In an alternative embodiment, the head 2, Fig. 3, for the electrode 8 is adjustable transversely of the axis of the workpiece by a slide 43 and eccentric 41, and a gauge 46 indicates the contact pressure between the electrode and the workpiece by measuring the deflection of a beam 45 on which the column 3 bears.