PURPOSE: To reverse a sheet even when it is thick by mounting a sheet support comprising an upper support substantially tangentially to a flat sheet transfer cylinder, and releasing the sheet from the sheet support with the trailing edge thereof leading the leading edge thereof.

CONSTITUTION: A sheet 13 is deposited on a sheet support 26 from the free sheet leading edge 13' when it approaches an edge part of the sheet support 26 at a sheet transfer cylinder side. This depositing motion is assisted by the feeding motion of a belt 30 itself. On this occasion, a gripper 38 reaches a position facing to the rotating direction (y) of the sheet transfer cylinder 15. Then a gripping pawl 23 is passed through a position opposite to the sheet support edge part 28, and performs the turning motion, so that the gripper 38 is faced to the direction opposite to the rotating direction (y) of the sheet transfer cylinder. During this motion, the sheet 13 is reversed. On this motion, the trailing edge 13' of the sheet is free from the bending or twisting. The additional travelling stroke (a) is generated because the sheet is covered by a peripheral face of the sheet transfer cylinder 15, whereby the sheet is pressed on the sheet support 26.