GB923866A - Improvements relating to machines for making welded tubes - Google Patents

Abstract

923,866. Making welded tubes; coiling helically-Jointed tubes. HOESCH A.G. June 29, 1960 [July 9, 1959], No. 22791/60. Classes 83 (2) and 83 (4). In a machine for making welded tubes from metal strip having means for bending the strip into tubular form and for feeding it thence to a tube seam welding device at a constant speed, there is provided a second driving means by which the strip can be fed forward at an increased speed to form a supply loop in advance of the bending device, a welding device for welding the end of a new strip and the end of the preceding strip and two supports, each for a coil to be operated on, which can be brought into an operative position alternately and are movable both in the direction of movement of the strip and transversely thereto. A steel strip 10 is fed tangentially into a sleeve 11, which forms it into a helically wound tube welded by a device near the outlet end of the sleeve, by constant speed rollers 14, 15 in a devide 13 and the strip is withdrawn from a coil 18 on a support 19 on a carriage 47. The strip passes from the coil through two normally open clamps 20,21 and through driving rolls 22,23 and along the dotted line path 25 through straightener 26 to the driving means 13. An edgetrimmer may be provided. When the coil nears its end, the rolls 22, 23 are speeded up to form a loop 27 supported by a roller on a lever 29 moved hydraulically into the full line portion of Fig. 1. The rollers 22, 23 are stopped with the end of the strip at 31 and the coil 18 is withdrawn and then moved transversely out of position and new coil 34 on a support 33 also on the carriage 47 is moved into position. The support 33 is moved forwards, the ends are clamped and welded and the strip fed to the sleeve 11 decreases the size of the loop. A looper pit may be provided. In a modification the sleeve 11, Fig. 3, driving means 13 and straightener 26 are arranged beneath the coils, clamps, welder and feed means 24 and the loop 40 is formed against a roller track 44, 45. The apparatus may be swung about a vertical apparatus to alter the angle of entry of the strip into the sleeve 11 and the upper part of the apparatus may be mounted to the left of the sleeve 11 in Fig. 3. A rotating mandrel may replace the sleeve 11.