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: In a sheet feeder device of the vacuum belt type, the vacuum belt moves in a pivotal manner between a generally horizontal sheet acquiring position, in which the lower face of the belt confronts the top surface of the top sheet, lying generally flat atop the underlying stack sheet; and a tilted position, in which the belt lifts the leading end of the acquired top sheet away from the underlying sheet, flexes it to insure its separation from the underlying sheet and delivers it endwise to a sheet receiving unit.