Abstract: A roll-wave sheet separator is provided which comprises a sheet support for supporting a stack of sheets and a sheet separator mounted adjacent to the stack which comprise a rotatable shaft having a helical peripheral thread coaxial with the shaft, and a follower rotatable around the shaft which follows the helical thread to move along the shaft axis. The follower supports at least one circular element which is preferably freely rotatable. The apparatus further includes a motor for rotating the shaft in one direction to drive the follower and its supported circular elements against the surface of the outermost sheet in the stack so that rotation of the circular element against the uppermost sheet in the stack will shingle that sheet from the stack. A brake is provided for abruptly stopping the rotation of the shaft whereby the follower and its supported element will then move back along the shaft out of engagement with the sheet surface.

Abstract: Apparatus for flipping document sheets such as paper or the like from one side to the other such that the document sheets may be stacked in a hopper in sequenced order after printing or copying on one side or used for printing or copying on both sides. The apparatus includes at least one rotatable cylindrical member having tapered slots disposed therein 180 degrees apart for receiving the leading edge of the sheet to be flipped, and a clamping member which permits the slots to remain open during the sheet insertion, clamp the sheet during rotation of the cylindrical member, and again permits the slots to open at the release point such that the flipped sheet may be released. The location and angle of the slots in the cylindrical member are such the initial force for rotating the cylindrical member is imparted thereto by the entry of document sheet into the slot.