PURPOSE: To prevent a sheet from falling off from a gripper bar by absorbing impact by the gripper bar by a fixed tensioner wheel, an automatic tensioner wheel and a spring.

CONSTITUTION: A roller chain 5 is suspended around a sprocket 3 of a spindle 2 and a sprocket 4 of an input shaft 17 of an intermittent feeder. By making a fixed tensioner wheel 6 contact with the outside of a return side of this roller chain 5 and making an automatic tensioner wheel 7 given springiness by a spring 18 contact with the outside of an advance side of the roller chain 5, impact applied on a sheet is prevented. Consequently, it is possible to eliminate falling of the sheet from a biting claw of a gripper bar suspended sideway on an intermittent transfer chain 21 and deflection and looseness easy to grow in the central part of the sheet.