Abstract: In a printing machine or the like wherein sheets are delivered seriatim into a receiving tray whereat the sheets come to rest by gravity onto a stack in the tray, a device for facilitating stacking the sheets into the tray at high speed. Each sheet is directed from the machine in a path outwardly over the tray. Guide surfaces act against a lead end of the sheet to prevent upward escape of the sheets from the path. A deflecting mechanism diverts each sheet downwardly into the tray to clear the path for a succeeding sheet. A stop plate is provided beneath the deflecting mechanism for acting against a trail end of each sheet to control and guide the sheet into alignment onto the stack in the tray.