A sheet feeder for feeding printed sheets to a conveying device, with a gripper drum that has at least one gripper for removing the printed sheets one at a time from a stack; a pocket is permanently mounted essentially in the peripheral area of the gripper drum wherein the printed sheets are aligned against a stop with the fold forward and set down on the conveying device with reversal of direction; and with a decelerating device for slowing the speed of the printed sheets downstream towards the stop. The decelerating device has at least one secondary stop, which rotates in the same direction as the gripper drum, has a slower speed than the gripper drum for slowing down the printed sheets, and on which the printed sheets are slowed down upstream of the stop.