GB411514A - New or improved method of, and apparatus or appliances for, electrically welding, steel or iron tubes - Google Patents

Abstract

411,514. Welding tubes. JACKSON, J. P., 83, Stanmore Road, Edgbaston, Birming- ham. Dec. 7, 1932, Nos. 34632/32 and 33872 /33. [Classes 83 (ii) and 83 (iv).] The longitudinal seams of steel or iron tubes are electrically welded by feeding an open seamed tube blank through a series of electrodes so as toheatnarrowzoneson opposite sides of the seam by current travelling only lengthwise of the edges, and subsequently pressing the edges together by rolls located beyond the electrodes. A strip b is fed through forming rolls a and then through three pairs of electrode rolls c<1>, c<2>, c<2>, the rolls c<1> and c<3> being respectively connected to phases c<4>, c<5> of a three wire two phase alternating current transformer and the rolls c<2> to the common return c<6> so that the current traverses the tube longitudinally. Each electrode may have a copper head c<7> insulated from a steel body c<8> and secured to a copper spindle dipping in a mercury bath connected to the transformer. The electrodes of each pair are angularly and laterally adjustable with respect to each other and each pair is longitudinally adjustable. The last pair of electrode rolls may be mechanically driven. The seam is aligned and also kept open during heating by a number of discs e mounted in brackets in a housing arranged over the electrodes and engaging the seam at points intermediate the pairs of electrodes. Each disc consists of two halves el, e<2> insulated from each other and from the spindle e<3> on which they are secured by a collar e' and nut e<8>. The spindle is mounted in bearings f<3> which are adjustable so that the discs may be adjusted transversely with respect to the tube. Welding is effected by pressure rolls d which are angularly and laterally adjustable relatively to each other and are longitudinally adjustable with respect to the electrodes.