Forming a cover from a sleeve and base

摘要

An apparatus for forming a cover comprising a base (4, Figure 1) welded to a sleeve 8 forming a side wall comprises at least one receiving jig 26 for receiving the sleeve and a working jig 30 carrying a hot wire electrical resistive element which cooperates with the receiving jig to form a continuous weld between the sleeve and base. The sleeve is placed on the receiving jig and a ram 35 moves the working jig into a welding position to form the seam. Two receiving jigs 26 may be provided, each moveable between a loading position and a working position aligned with the working jig. Biassing means may be provided to keep the welding wire under tension to accommodate longitudinal expansion and contraction.