Abstract: In connection with a device for catching a torn web of printed material with a roller actuated by a drive-mechanism, the roller is arranged within an area where the tearing of webs is likely to happen, preferably behind the last roller unit of a rotational roller printing machine, and with a free turnable rotor arrangement which is pressed against the roller and is arranged on a movable carrier in the machine trestle. The carrier can be actuated by an actuating device if the web tears. A simple and robust construction a well as economical operation can be assured in that the actuating device contains at least one pneumatic cylinder which is highly pressurized to move the rotor arrangement towards the roller and which presses the rotor arrangement against the roller at reduced pressure.