PURPOSE: To facilitate corner cutting by providing rotary rollers, an air nozzle and roll pressing devices in the position of narrow conveyor position so as to separate and stretch the wound end of a roll and also to hold it stably, and then performing required cutting by a corner cutter.

CONSTITUTION: Roll pressing devices II, II' are integrally slid along the travel centerline of a conveyor line to move a following roll R onto a narrow conveyor. The travel of the conveyor is then stopped, and the roll pressing devices are elevated. At the same time, rotary rollers 6, 7 are rotated to transfer the roll on the thin conveyor onto the rotary rollers. The rotary rollers are driven/ rotated, and air is jetted from an air nozzle 26. With this jet flow, the wound end of the roll is separated, and this wound end is stretched on an anvil 25. The roll is further rewound by the rotary rollers and pushed out by the required length. The driving of the rotary rollers is then stopped, and a cutter 24 is brought into contact with the sheet end to perform corner cutting.