GB462895A - Improved apparatus for arc welding - Google Patents

Abstract

462,895. Uniting by fusion. BABCOCK & WILCOX, Ltd. June 15, 1935, No. 33123/36. Convention date, June 16, 1934. Divided out of 458,269. [Class 83 (iv)] In an arc-welding machine, a coated rod having a core with spaced projections presenting bared spots at least flush with the surface of the coating is fed through the welding head by rollers carried thereby, one at least of which is driven, and the spots are engaged by separate resilient electric contact means carried by the head. The welding head P is fixed to a support 16 vertically adjustable in a beam N, which carries a rack 3 and may be traversed by a motor 6 through reduction gear when welding longitudinal seams. A backing-up strip 33 for engaging the seam when welding longitudinal, transverse or circumferential seams is supported by a jack 32 in a member 31 connected at opposite sides by cables 29, 39 to the opposite ends of the beam so that it may be moved with the beam when welding longitudinal seams. In welding circumferential seams, the work O, such as a tank or penstock, is mounted on pairs of rollers 18, 19 rotated by a motor 26 through reduction gear 27. The support 16 carries a circular bracket 42, Fig. 2, having a journal pin 46 on which the welding head frame 48 is mounted. The bracket has a toothed sector 43, Fig. 6, engaging a worm 51 on a shaft 53 carried in bearings on the frame 48, so that angular adjustment of the head in a transverse plane may be effected by a hand wheel 65 through bevel gear 63, 58. Mounted on the frame 48 in bearings 69, 70, Fig. 3, is a shaft 71, which may be rotated by a hand wheel 83 through bevel gear 79, 74, so as by means of a pinion 72 and rack 73<a> to adjust longitudinally a member 87 carrying the weld rod feed means to position it with respect to the groove of a circumferential seam. This member 87 has guiding members 88 engaging guide surfaces 85, 86 on a member 84 on the side of the frame 48. On the member 87 is mounted a reversible electrode feed motor 114 which through reduction gear in casing 113, shaft 115 and further gear rotates either of two pairs of rolls X, Y, Figs. 9 and 10, arranged in planes at right-angles to each other and respectively used when welding longitudinal or transverse and circumferential seams. The shaft 115 is connected by bevel gear 118, 120 with a shaft 119, Fig. 9, mounted on ball - bearings within a hollow pintle 93 to which the roller, head and gearing therefor is secured. The rolls X are connected by spur gear 131, 131<1>, Fig. 11, the former of which is geared to a pinion 122 on the shaft 119. The pinion 122 also engages a pinion 132, Fig. 10, which meshes with a gear 134 on a shaft 135 driving one of the rolls Y through bevel gear 138, 139. The rolls Y are geared together. The feed rolls are all provided with rubber inserts. In order to effect angular adjustment of the electrode in a longitudinal plane, a toothed sector 103 is keyed to the pintle 93 and engages a worm 107 mounted in bearings on the member 87 and operated by a hand wheel 111. The rolls are fixed on their shafts by nuts so that one set may be removed when the other is in use. The coated electrode has bared projections 300, Fig. 13, at least flush with the surface of the coating and arranged parallel with the axes of the rolls. The current is supplied by contact shoes carried at the ends of arms 304 pivoted on a casing 301 and drawn together by springs 307. The casing is suspended from the head by a swivel joint 302 so that it may be turned round with the rod to suit longitudinal or transverse seams. Specification 458,269 is referred to.