Patent ID: 7191690

Claim:
A method for cutting a ribbon, comprising: providing a cutting unit including, a pair of cylinders disposed opposite one another with a gap formed there-between for receiving a ribbon on a travel path, the pair of cylinders including a first cutting cylinder having a periphery with a cutting knife disposed helically about the periphery and a second cylinder, one drive rotating the first cutting cylinder at a speed proportional to the speed of the ribbon for cutting the ribbon and providing a signature cut from the ribbon with a smooth, straight edge, a subframe having a pivot point, the subframe being pivotable about the pivot point, the subframe supporting the cylinders, and the subframe controlling a position of the cylinders in regard to the ribbon and therefore controlling a cutting length of the ribbon, and a further drive connected to the subframe for pivoting the subframe about the pivot point; changing the length of the ribbon by controlling the further drive to change the angular orientation of the pair of cylinders relative to the ribbon; and contemporaneously with the step of controlling the further drive, controlling the one drive to change a rotational speed of the pair of cylinders such that a component of travel of a point of contact between the pair of cylinders in a direction of travel of the ribbon matches a speed of the ribbon for cutting the ribbon such that a signature cut from the ribbon has a smooth, straight edge extending substantially perpendicular to the traveling direction of the ribbon on said travel path.