a collector for stacking sheets of paper , plastics , and cardboard has a feeding device and a tray downstream of the feeding device in the feeding direction . the tray is arranged in a lowered position relative to the feeding device . a stop is provided downstream of the tray . at least one transport roll transports sheets individually from the feeding device onto the tray to form a stack . an adjusting element is arranged in an area where the feeding device and the tray adjoin , wherein the adjusting element is adjustable between a lowered rest position and a position of use lifted relative to the rest position . in the position of use , the adjusting element lifts a trail end of a first sheet that has reached the tray such that a following second sheet is moved into a position underneath the trail end of the first sheet .