Patent ID: 7934301

Claim:
A method of manufacturing expanded metal forming a grid of openings and having a first repetition length in a first direction and a second repetition length in a second direction perpendicular to the first direction, such that the first and second repetition lengths have a predetermined ratio, which method comprises the steps of providing pre-expanded metal having a stretching direction coinciding with the first direction, and forming a grid having a ratio of first and second repetition lengths that is smaller than the predetermined ratio; and applying expansion force along the first direction, at a plurality of points at various positions with respect to the second direction, until the predetermined ratio of repetition lengths is obtained, wherein the expansion force is applied using a plurality of force transmitters co-operating with the plurality of points, and wherein the force transmitters are arranged on a tool comprising a hingeable grid, wherein said hingeable grid comprises two sets of parallel members connected with joints having pivots which extend out of the plane of said hingeable grid and into each opening of said pre-expanded metal, said pivots being suitably shaped to serve as force transmitters.