PURPOSE: To attempt to lengthen the life of a lateral perforating blade by reducing impact at the time of processing lateral perforation by such an arrangement wherein the lateral perforating blade is tilted from the axis of a lateral perforating cylinder by slanting the axis of the lateral perforating cylinder from the axis of a blade pad cylinder.

CONSTITUTION: A plate-like lateral perforating blade 34 is caused to tilt from the axial center of a lateral perforation cylinder 24 by slanting the axial center of the lateral perforation cylinder 24 for the axial center of a blade receiving cylinder 21. Then, the lateral perforation cylinder 24 is caused to rotate, and the tilt angle of the lateral perforating blade 34 is to be controlled so that the longitudinal direction of a tip of the blade 34 becomes perpendicular to the feed direction of a sheet of paper to be fed toward the blade receiving cylinder 21, when one end of the tip located at the front side of the rotating direction of the perforating blade 34 is brought to contact with the outer circumference of the blade receiving cylinder 21. As the printed sheet of paper 3 is fed into an attachment 20, the sheet 3 is caused to wrap around the outer circumference of the blade receiving cylinder 21 and it rotates together with the cylinder 21, during which the lateral perforation is processed by the lateral perforating blade 34.