Cold butt welding machine - esp. for joining thin thin aluminium strip used as a tubular sheath in data transmission cables

摘要

Machine for the cold pressure butt welding of wire or strip by upsetting, using two pairs of clamping jaws to hold the two workpieces being joined. The jaws are provided with matching recesses to hold the workpieces and notches into which the upset metal can flow. A guide locates the jaws while they move together during welding. For clamping metal strip coated with plastic on one or both sides, the jaws are mounted on guide bars which provide the machine with rigidity and also permit a clamping pressure of up to 70 KN to be applied by separate hydraulic cylinders to each pair of jaws. Another hydraulic cylinder provides the welding pressure via wedges on the jaws. Used for cold butt welding two Al strips with cross-section 50 x 0.2 mm, coated on both sides with 50 mu m of plastic. The very long strip obtd. is bent to form a very long tube with overlapping edges round a cable core. Polythene is then extruded round the coated Al tube, the finished cable being used for data transmission.