GB809129A - Apparatus for fusion butt welding the adjacent longitudinal edges of tube lengths - Google Patents

Abstract

809,129. Making tubes; welding by fusion; angular bending. LINDE'S EISMASCHINEN A.G. FUR. Oct. 25, 1955 [Nov. 25, 1954; May 18, 1955], No. 30505/55. Classes 83 (2) and 83 (4). In a machine for fusion welding the longitudinal edges of pre-bent tubes lengths comprising a feed-bed constituted by a plurality of coaxial and at least partially annular supporting elements, a plurality of feed rollers for moving each length and pressure rollers for contacting each length and welding means for welding the longitudinal edges, the pressure rollers are provided with mountings arranged circumferentially on the elements and directed inwards and each pressure-roller mounting is constructed to permit free rotational movement of its roller about an axis during movement of each length whilst maintaining the direction of the axis normal to the direction of motion of the portion of the length contacted by the roller so that the roller contacts the length with only rolling friction. In an embodiment a pre-bent tube 1, Figs. 1 and 2, is fed by driven rubber-coated rollers 6 towards the welding-point 3 through support elements 2 each having a series of pressure rollers 10 to elastically close the open slit in the tube. Each pressure roller comprises a ball supported by smaller balls in a partspherical recess in the end of a plunger spring pressed towards the tube. A support bar mounts idler rollers 7 and is carried by a member 8 projecting through the slit in the tube. A coded copper saddle may be carried by the member 8 to engage the seam. The pressure rollers may have castor mountings. In a further embodiment tube lengths which have been welded internally in an apparatus similar to that of the first embodiment are fed by rollers 6a, 6b, Fig. 4, through annular or nearly annular elements 2 similar to those of the first embodiment to a weld head arranged over the point 3. The axes of the rollers 6a are swingable independently of those of rollers 6b and the speeds of the rollers are relatively adjustable to allow the rotation of a tube length until its seam is in the correct position. Two abutting tube lengths may be welded if the axes of the rollers 6a, 6b are arranged parallel to the tube axes. The pressure rollers may be gas or fluid pressed. To weld the internal seam of a tube the welding head is fixed to a support-bar within the tube which latter travels with its seam downwards and a cooled copper saddle is pressed against the outside of the seam.