Abstract: The trimmer includes: a pusher 2 that pushes the bound material 1; a pusher moving device that moves the pusher; a positioning part 111 that positions the bound material pushed by the pusher; an allowable position memory that memorizes an allowable position range relevant to the pusher; an allowable reaction force memory that memorizes an allowable reaction force range relevant to the pusher; and a determiner that determines whether a length of the bound material is normal or abnormal. The determiner determines that: the length L of the bound material is normal; or the length L of the bound material is abnormal.

Abstract: The trimmer includes: a pusher 2 that pushes the bound material 1; a pusher moving device that moves the pusher; a positioning part 111 that positions the bound material pushed by the pusher; an allowable position memory that memorizes an allowable position range relevant to the pusher; an allowable reaction force memory that memorizes an allowable reaction force range relevant to the pusher; and a determiner that determines whether a length of the bound material is normal or abnormal. The determiner determines that: the length L of the bound material is normal; or the length L of the bound material is abnormal.

Abstract: A buckle (3, 4) is provided with a position adjustable stopper (5, 6) for stopping a sheet (P) by coming into collision with the leading edge of the sheet (P) so as to position the sheet in a fold position. In the inlet of the buckle, there are provided a pair of rotary drive folding rollers (20a, 20b; 20c, 20d) for taking the sheet in the buckle, and a pair of rotary drive folding rollers (20b, 20c; 20d, 20e) for folding a portion of the sheet deflecting from the buckle. A sheet detector (16, 17) is arranged in the buckle at a predetermined spacing from the stopper. A control section (29) outputting a signal for deceleration to a driving source of the roller upon reception of a sheet detection signal from the sheet detector and stopping output of the signal for deceleration after elapse of a predetermined time.