GB362651A - Method of welding circumferential seams and apparatus therefor - Google Patents

Abstract

362,651. Uniting by fusion. AIR REDUCTION CO., Inc., 60, East 42nd Street, New York, U.S.A. Nov. 25, 1930, No. 35453. Convention date, Dec. 16, 1929. [Class 83 (iv).] In welding circumferential seams between aligned sections of pipes the adjacent edges are secured together and one of the sections is rotated by power to cause the seam to travel through a region of high temperature such as that produced by an oxyacetylene flame. The pipe sections are fed from a storage rack S, which may be part of a pipemaking plant, and pass down runways 12 to a table T where two sections are placed in alignment and tack-welded at a number of points spread around the seam. A stop 14, Fig. 3, facilitates the delivery of the pipe sections one by one to rollers 25 mounted in recesses provided in channel beams which are supported on further beams 19. Additional rollers 27 are provided to facilitate axial movement of the pipes into abutting relation, these rollers being mounted in U-shaped members 31 which are guided in plates 35 and are moved vertically by means of hydraulic cylinders 37, Fig. 3. During the tack-welding operation, the rollers 27 are lowered out of contact with the pipe sections, which can then be easily rotated on the rollers 25. The rollers 27 are then raised and the joined sections are moved along a conveyer 39 to the welding machine W, which is supported on a base 38 which preferably also carries a number of roller supports 20. A cylinder 44 carried in standards 40 carries at each end a chuck 46 for gripping one of the pipe sections. The cylinder is provided with a gear 48 driven by a pinion 50 on a shaft 52 driven by worm gearing 62 from a main shaft 64, Fig. 8. The latter carries a low-speed loose clutch member 68 which is driven by worm gearing 71 from an electric motor 28 and a high-speed clutch member 66 driven from the spindle 72 of a separate motor 26. A splined clutch sleeve 90 is operated from a handle 98 through levers 96, 92 to engage either drive with the shaft 64, the clutches being of the multiple disc type so that the slipping which takes place during the engagement of the low speed gives a braking effect and produces a gradual reduction in the speed of the work. When the high speed is in operation, the flame effects a preheating of the entire seam without causing fusion, the actual weld being produced when the low speed is in use. The high-speed motor may be provided with a starting rheostat and the low-speed motor with a drum controller 108 for regulation of its speed. In some cases the preheating motor may be dispensed with and the required speed changes obtained from a single motor. The roller system which conveys the work to and from the welding machine comprises transporting rollers 112 on transverse axes and supporting rollers 114 which support the work during welding. The rollers 114 are accurately aligned to support the work concentrically in the chucks and are carried in adjustable cradles 115. The transporting rollers 112 are guided in side members 120 and are mounted in slides connected to cross-heads 122 which are moved vertically by gearing consisting of a hand-wheel 138, longitudinal shaft 132, worm gearing 126, and screw 124, so that the rollers 112 may be raised while a pipe section is moved into the chucks and then lowered to place the work on the rollers 114. In modifications the rollers 112 may be actuated hydraulically or by hand-operated ratchet mechanism. The welding unit 32 comprises a lower slide 34 movable longitudinally by means of a handwheel 152 and an upper transverse slide 154 carrying a standard 155 and screw-operated from a handwheel 161. The standard carries a swinging arm 165 provided with a torch holding bracket 160 which is of the type described in Specification 155,461, [Class 75 (i), Burners &c.], and incorporates longitudinal and vertical adjustments of the torch 170 which is preferably of the type described in Specification 162,431, [Class 83 (iv), Metals, Working]. The torch may be water-cooled and may be fed with wire through a tube 174, the adjustable feed mechanism being operated by a motor 180. After completion of the welding the rotation of the welded sections may be continued to straighten the pipe. The machine may be arranged to produce continuous lengths of pipe, the unclamped sections being supported on sets of rolls 114 during the welding operation. Specification 303,896, [Class 83 (iv), Metals, Working], is also referred to.