Load bearing panel with stiffening web - is made with array of punched, cold-formed domed projections

摘要

A load bearing panel is made from a top sheet and a stiffening web which is made by giving a flat sheet several projections to make it more rigid. The flat sheet is deformed by cold die forming using circular or nearly circular dies and circular, domed punches so as to form domed projections in the sheet. The arrangement of dies and punches is such that no straight line can be drawn across the region of the circular dies without intersecting at least two of them.