Abstract: Apparatus for feeding sheets seriatim from a sheet supply stack. The apparatus comprises a sheet feed head assembly including a plenum, a vacuum source in flow communication with the plenum, and a mechanism, such as a feed belt, for example, associated with the plenum for urging a sheet acquired by vacuum in a sheet feeding direction away from the sheet supply stack. The sheet supply stack is supported, for example in a hopper on a support platform, so as to maintain the topmost sheet in such stack at a predetermined level in spaced relation with respect to the urging mechanism of the sheet feed head assembly. A first positive air supply directs a flow of air at the sheet supply stack to levitate the top several sheets in the supply stack to an elevation enabling the topmost sheet to be acquired by vacuum from the sheet feed head assembly plenum; and a second positive air supply directs a flow of air at an acquired sheet to assure separation of any additional sheets adhering to such topmost sheet.

Abstract: Sheet feed apparatus including a scuff feeder for reliably transporting sheets from the bottom of a stack of sheets without marking of the sheets. The sheet transport apparatus comprises a retard device, located in contact with the lead edge, in the direction of sheet feed, of a sheet stack for preventing double feeding of sheets from the sheet stack. A scuff feed belt is located to have a run extending in the direction of sheet feed substantially above the surface of the tray and below the retard device to form a sheet separation nip with the retard device. The run of the scuff feed belt presents an area of contact with the sheet stack to carry about 50% of the weight of the sheet stack. Additionally, the scuff feed belt of the scuff feeder and the retard device respectively have a plurality of grooves oriented in the direction of sheet feed.