Rear jet air knife

A top sheet feeding apparatus for feeding sheets from a stack of sheets comprising a sheet stack support tray for supporting a stack of sheets, an air fluffer positioned adjacent the stack of sheets, an air knife device positioned adjacent the front of the stack of sheets for applying a positive pressure to the sheet stack in order to separate the uppermost sheet in the stack from the rest of the stack, and a feedhead device including a vacuum plenum chamber positioned over the front of the sheet stack having a negative pressure applied thereto during feeding, the vacuum plenum chamber having a sheet corrugation member located in the center of its bottom surface and perforated feed belt means associated with the vacuum plenum chamber to transport the sheets acquired by said vacuum plenum chamber in a forward direction out of the stack support tray, wherein the air knife device includes a first air nozzle and a pair of second air nozzles extending from the rear portion of the air knife device, the second air nozzles being located different than the first air nozzle relative the front of the sheet stack, and having a substantially constant cross-section.