Patent ID: 7381476

Claim:
A structural element having a metal wall of generally tubular shape and polygonal cross-section, the element consisting of: at least two segments that are not in axial alignment; a plurality of wall portions, in angular dispositions relative to one another, that are joined together by fold lines in a single metal blank; each segment comprising at least one additional overlap and fixing tab for fixing its wall portions together; and at least one segment comprising at least one additional tab for fixing the segments together, said additional overlap and fixing tab of each segment and said additional tab for fixing the segments together being superposed on at least one of a wall portion and a second overlap tab of the element and fixed to said at least one of a wall portion and a second overlap tab of the element solely by at least one weld line or weld spot, the structural element as a whole being assembled together solely by said at least one weld line or weld spot of said at least one overlap and fixing tab of each segment and said at least one weld line or weld spot of at least one tab for fixing the segments together, said at least one overlap and fixing tab of each segment being in a superposed position bearing resiliently on at least one of the wall portion and the second overlap and fixing tab, and said at least one tab for fixing the segments together being in a superposed position bearing resiliently on at least one of the wall portion and the second overlap and fixing tab, whereby the structural element is stiffened, wherein the structural element is a closed hollow body, and wherein the structural element is a complex curved section member of polygonal section, or an annular piece of hollow polygonal section.