PURPOSE: To secure correct return to the original condition in such a way that is limiting block which faces an exit roller is pivotally fixed so as to be rocked by a control lever, the limiting block is positioned by an adjusting screw equipped with adjusting dial, so that opening of the limiting block can be made by one operation.

CONSTITUTION: In case where paper piece is jammed between an exit roller 5 and a limiting block 6, the limiting block 6 moves together with an adjusting plate 7 through a pin 9 against a spring 15 in the direction of being separated from the exit roller 5 around a shaft 8 acting as the center when a control lever 10 is operated once in the direction of an arrow. In consequence, the jammed paper piece can be easily taken out. When the operation of the control lever 10 is released, the mechanism can be returned to the original condition by impetus force of the spring 15. This turning rate can be determined by adjusting screw 12 which is regulated by an adjusting dial 13. Thus, opening of the limiting block can be made easily by one touch, so that returning to the original condition can be achieved correctly.