GB517714A - Improvements in welding machines - Google Patents

Abstract

517,714. Collectors. BARTON CONDUITS, Ltd., HOLT, W., and PRICHARDS, A. May 5, 1939, No. 13002/38. [Class 38 (i)] [Also in Group XXII]. A machine for welding tubes, includes a pair of rotatable disc electrodes arranged on opposite sides of the seam and having indirect electrical contact therewith contact discs or rings rotatable with the electrodes and dipping into a container for conducting liquid such as mercury, the contacts being formed with one or more annular grooves co-operating with shaped parts of the container to define a narrow gap therebetween. The electrodes 16, which are spaced apart by an insulating disc 30 of smaller diameter so as to provide an air gap, have arranged on the outer sides thereof copper contact rings 31 which may be nickelplated and are provided with flanges 32 and with cylindrical portions 33 engaging the central holes in the electrodes. The electrodes and rings may be secured together by insulated bolts 34 or each electrode may be secured by studs to the flanges and to each other by separate studs or bolts. The electrodes and rings are located by nuts 36 on a spindle 17, which may be of insulating material or of metal insulated from the contact rings, and which may be stationary or rotatable with the electrodes. The rings may have phosphor bronze bushings 35 or ball or other bearings. The blocks 18 to which the spindle 17 is fixed have brackets 45 provided with insulation 46 on which are supported mercury pots 44 in which dip the contact rings 31. The pots are connected by flexible conductors to the terminals of a transformer and are provided with half-round or V-shaped ribs 50 in their base engaging similar grooves in the contact rings. The pots have gauges or sight glasses and drain taps.