GB1274992A - Apparatus and method for fillet welding - Google Patents

Abstract

1,274,992. Welding by fusion. NIPPON KOKAN K.K. 19 March, 1970, No. 13445/70. Heading B3R. T-joints between re-inforcing plates B 1 and a baseplate A, e.g. in shipbuilding structures, are each effected by simultaneous deposition of fillet welds at both plate/baseplate corners. The apparatus comprises twin welding heads 19 supported by a saddle-shaped carriage 8 movable, in operation, parallel to the plates B 1 along a beam 3 of a gantry which, to position the heads in relation to the T-joint to be welded, is movable, by a motor 5, via wheels 4, on rails 7 transversely of the plates B 1 . The carriage 8 is driven along the beam 3 by drive means 9 through racks and pinions 11, 10. The gantry may be clamped at 40 to the rails. The welding heads 19 are pivotally carried by a pin 20 on a clevis 15 carried by a shaft 13. The latter is vertically adjustably movable in a housing 16 fast with the carriage 8 by a motor 18 acting on the shaft 13 through a rack-and-pinion or worm-and-nut. The heads 19 are urged by gravity to swing towards each other at their lower ends and may be swung away from each other by fluid pressure in cylinders 21 acting on pistons 22 carrying rollers 23 engageable with the plates B 1 . Each welding head carries successively in its welding line a fillet corner engageable guide roller 24, a flux-spraying nozzle 25, leading and trailing electrodes 26, 27 and a flux-retrieval pipe 28. Filler wires 29 from spools 31 are fed by devices 32. Excessive flux retrieved at 28 is recirculated to the spraying nozzles 25 through impurity-separating tanks 30. An operator stand and reels 35, 36 are provided on the carriage 8, and welding power cables 39 are carried by gantry trolleys 38. The plates B 1 are temporarily tack-welded to the baseplate A before being conveyed to the welding station. On completion of a welding pass, the heads are raised for the carriage 8 return, the rollers 23 engaging higher on the welded plate B 1 .