Patent GB-133130-A (GB)
IPC: B21C37/12
Abstract: 133,130. Withers, J. S., (Naylor-Robertson Co.). Sept. 25, 1918. Pipes and tubes.- Pipes and tubes of any required length are made by helically winding a strip on a mandral which is rotated and at the same time moved axially until a section of tube has been completed thereon, and is then contracted and partly withdrawn from the finished section to allow a further section to be wound in continuation of, and in a similar manner to, that already formed. By welding succeeding strips end to end the process can be continued indefinitely to form a continuous tube of any length. The edges of the strip are folded together to form a helical seam 105, Fig. 21. The strip material 100 passes between pairs of rollers 99, 103, 106, 107 which form an upstanding flange at one edge and a groove or bead at the other. The rollers are mounted in a frame carried on a support such that the angle at which the strip is presented to the mandrel can be adjusted. The strip then passes round the mandrel 31 which is rotated and moved axially so that the strip is wound helically. As the strip is being wound, the upstanding flange at its edge enters the bead or groove in the edge of the adjacent convolution, the groove being closed to grip the flange, and the two bent down and flattened against the outer surface of the tube by adjustable rollers 148, 153, 156, 160 disposed around the mandrel. Rollers 140 are also provided to keep the flange upstanding during passage round the mandrel prior to being engaged by the bead. Rotation of the mandrel draws the strip material into the machine, and co-operation of the rollers with the helical seam gives the forward movement to the mandrel during the winding operation. The mandrel 31 is slotted at 70 and is supported by shoes 80 and links 79 on a shaft 30 which is rotated and can move axially. The disposition of the links causes the mandrel to expand when rotated in one direction and contract when rotated in the opposite direction. The expansion of that portion of the mandrel on which the tube is wound is limited by stops 83, but the expansion of the free end of the mandrel which is not entirely withdrawn from the completed portion of tube is not so limited. This construction keeps the bore of the tube uniform, but also allows the expanded mandrel to grip the tube frictionally. The shaft 30 carries a gear wheel 34 engaging with an elongated driving pinion 35 so that meshing is maintained during the endlong movements of the mandrel and shaft. A motor 25 drives a shaft 41 through chain or belt gear 40 and spur wheels 38, 42. The pinion 35 is driven from the shaft 41 in the direction to wind a section of tube through gear wheels 43, 44 and a clutch 50. When a section of tube has been completed, the mandrel is rotated in the opposite direction through chain or belt gear 47 and a clutch 51, the clutch 50 being thrown out of, and the clutch 51 into, engagement by means of a lever 64 operated by hand or by adjustable tappets. At the same time the mandrel is retracted by a pinion 57 engaging a rack 32 and driven through bevel gear 53, 55 and a unidirectional clutch 58 of pawl and ratchet-wheel type The rack 32 is connected to the end of the shaft 30 by a joint 33 allowing rotation of the shaft, and carries the tappets 65, 66 for automatically controlling the clutches 50, 51.