Method of fabrication of metal boxes e.g. for decorative panelling on outside of building - includes steps of fabrication of panel having protective covering, cutting edges of this panel and chamfering edges before folding

摘要

The box, e.g. of aluminium, is made by cutting away the corners of a flat square or rectangular panel and chamfering the edges of the cut-away portions so that they form a close-fitting joint when the edge portions (10.3) of the panel (10.1) are folded over at right angles to make the sides of the box. The folded edges of the box can also be subjected to an external pressure to round the corners of the box and produce a closer fit of the meeting edges prior to painting. ADVANTAGE - Improved appearance and longer life by increasing resistance to weathering.