Device for in-line perforation of continuous webs of material

In a perforating unit of a printing machine, a device for in-line perforation of a continuous web of material in a gap between a pair of cylinders, the web being printed on at least one side thereof, both of the cylinders being held in side walls of the perforating unit and being driven, and one of the cylinders carrying elements for perforating the web of material, comprising a draw roller disposed downstream of the perforating-cylinder pair as seen in the direction of travel of the web of material for drawing the web of material through the perforating, and for holding the web of material taut and for deflecting the web away from the perforating unit, and a drive motor exclusively associated with the perforating unit and connected with said draw roller and the perforating-cylinder pair for simultaneously driving said draw roller and the perforating-cylinder pair, and an angle of rotation sensor disposed at said perforating-cylinder pair for setting a phase lead or phase lag of said perforating cylinder via said drive motor.