Abstract: In a signature delivery device in which signatures of paper sheets folded by a folding machine of a rotary printing press are conveyed by an endless conveyor belt to a horizontal type stacker in a partially overlapped state and at the stacker the signatures are inverted and then sequentially inserted beneath a stack of previously stacked signatures, there are provided a first roller in contact with a lower surface of the endless conveyor belt and rotated at a peripheral speed substantially the same as a running speed of the endless belt, a second roller mounted on a shaft in parallel with the first roller for clamping the conveyor belt and the signatures conveyed thereby between the first and second rollers, and drive gears for rotating the second roller at a peripheral speed lower than that of the first roller so as to slightly lay an upper sheet of each double fold signature with respect to the lower sheet.