Patent ID: 6115905
Filing Date: 2000-09-12
Classification: B21D,Y10T

Abstract:
A method for connecting laminated metal plates with each other, said metal plates having an essentially planar surface and a predetermined thickness, the method comprising the steps of:forming two cutting lines independent of each other in the laminated metal plates, and cutting the laminated metal plates to form first cut end faces and second cut end faces of the planar surface of the laminated metal plates along said cutting lines with a male mold die and a female mold die, said male mold die having a step larger in height than the thickness of the laminated metal plates;pressing the male mold die in a laminated direction toward the female mold die so as to form a projecting portion of the laminated metal plates with the first cut end faces between said two cutting lines in the laminated metal plates such that the first cut end faces of said projecting portion engage with the second cut end faces of the planar surface of the laminated metal plates; the step of pressing the male mold die then providing for forming the projecting portion to have a center portion protruding to a highest position from the planar surface of the metal plates, and forming the projecting portion to have a pair of slant surface portions slanted from the center portion towards said planar surface of the metal plates, and forming the projecting portion to have four slant forming portions which are a part of said cutting lines and define said pair of slant surface portions, wherein the slant surface portions are respectively aligned with lines which outwardly extend radially from said center portion so as to form an outwardly tapered skirt portion of said slant surface portions.