Patent ID: 7735348

Claim:
A method for bending a planar sheet for shaping into an open seam tube in a bending press comprising: a press frame; a sheet, clamped in place in the press frame, the sheet further comprising a boundary edge having a bevel configured for welding to a correspondingly configured opposing second edge to form a longitudinal tube seam; an upper tool, shaped to correspond to a bending contour to be achieved and rigidly arranged in the press frame; a lower tool, which may be displaced vertically, opposed to the upper tool between which the boundary edge is bent into a desired boundary contour in one work step, wherein at a beginning of a bending operation, a bottom face of the boundary edge, which comes into contact with a working surface of the lower tool, comes into planar contact; the planar contact being maintained during the entire bending operation by means of a combined motion of the lower tool comprising vertical displacement and simultaneous pivoting about a rotational axis.