Patent ID: 6640605
Filing Date: 2003-11-04
Classification: B21D

Abstract:
A method for bending two opposing sections of sheet metal of thickness T about an interposed bending line to form a 3-dimensional folded structure, said method comprising the steps of:forming a plurality of elongated slots of length a and width b within said metal along said bending line, said elongated slots having at least one edge of major length that is generally parallel to said bending line, said slots being separated by a distance c along said bending line, said slots being formed by a cutting device of width k; and bending said two opposing sections of metal sheet about said bending line, said plurality of slots encouraging said bending to occur along said bending line, whereina is not less than c but not greater than 30 times c, b is not less than k but not greater than 2 times T, c is not less than T/2 but not greater 3 times T, and wherein said bending line is selected from a group comprising the following:a straight line, a line curved in one direction, a line curved in two directions and having at least one S-shaped line segment, an irregular curved line, and a combination of straight and curved lines.