Patent ID: 7708679

Claim:
A folding device for folding a foldable blank having an internal surface and an external surface, the folding device comprising: a conveyor configured to convey the blank through the folding device in a conveying direction; an internal tool positioned and configured to guide the internal surface of the blank; an external tool positioned and configured to guide the external surface of the blank and positioned opposite the internal tool; the internal tool being configured to oppose and to cooperate with the external tool to form a longitudinal fold in and along the blank in the conveying direction as the blank is conveyed past the external tool, and the external tool being positioned and configured to fold the blank when the blank is conveyed past the external tool; and a supporting guide contacting the external face of the foldable blank, comprising a longitudinal surface having a helical shape in the conveying direction and being configured to cooperate with the internal tool for sandwiching the fold.