METHOD OF MAKING SHEETS WITH TRAPEZOIDAL CORRUGATIONS Russian patent published in 1995 - IPC

FIELD: metal pressure forming. SUBSTANCE: method of shaping corrugated sheets comprises steps of successive from pass-to-pass bending up of portions of strip blank with use of grooved rolls, beginning from a mean part of the blank, with formation of trapezoidal corrugations; bending up portions of the blank in one pass by angle 15-30 degrees, and, when inner faces of corrugations, adjacent with mean corrugations, are inclined by a predetermined final angle of bending, releasing the mean corrugations out of contact with the rolls until bending outer faces of the adjacent corrugations by the final angle value; and simultaneously once more passing the mean corrugations through the grooved roll pass. EFFECT: lowered cost of rolled stock production with the same high quality of it. 1 cl, 1 dwg