Wall or ceiling element of metal sheet has embossing on sidewalls which produce length shortening or length extension of free edge of sidewalls to create concave or convex curvature of plane surface of ceiling element

摘要

The rectangular wall or ceiling element of metal sheet has sidewalls (2) bent up on opposite-lying edges. The side walls has embossed elements (3) which produce a length shortening or length extension of the free edge (4) of the sidewalls so as to create a concave or convex curvature of the plane surface (1) of the ceiling element. To reduce the original length dimension of the free edge of the sidewall, protrusions are formed by embossing, and to lengthen the free edge the sidewalls have sections of reduced thickness produced by squeezing to create material displacement.