Process for producing a curved rigidity member

摘要

A flat, flexible lightweight panel(12) with outer layers(14,16) on both sides is cut to the shape and size of the required roof stiffening panel(10). Local impressions are made in the panel at the points at which curved areas are to be created and the shortening of the impressed facing layer causes the panel to bend about these points. Stiffening panels(10) are cut from larger flat sheet with a punching tool. Local impressions are formed by making grooves or channels(22). A combination tool, e.g. a flat bed punching tool, which forms the grooves and cuts out the panel in a single operation may be used.