PURPOSE: To correct the rise of a stitch portion of copy sheets by providing a pair of rollers or slide projections on a pin feed means.

CONSTITUTION: Respective pairs of rollers 26, 27 disposed at the upstream side of pin wheels 21 of left and right housings 23 are rotatably attached to the widthwise positions coinciding with a space between left and right stitch portions 5, 5 of a continuous copy sheet 1 to engage or press the front and back of said sheet 1 passing between the housing 23 and a lid member 24. When said sheet 1 passes by a pin feed means 19, the stitch portions 5, 5 at both sides of copy sheet are pressed by pairs of left and right rollers 26, 27 so that the rise of the stitch portions is corrected to give the same thickness to the whole surface of sheet 1 including the flat portion except for the stitch portions 5.