Vertical rise sheet feeder

摘要

A vertical rise sheet feeder is provided comprising means responsive to the weight of a stack of sheets for positioning and maintaining the stack at a feed level for the feeding of a single sheet at a time from the top of the stack. The sheet feeder includes a fixed platform and a vertically movable platform for supporting the stack. The movable platform is powered by a stabilizer means and its movement is regulated by linkage means interconnected by a torsion bar. The torsion bar controls operation of the linkage means in unison and provides a degree of freedom to the movable platform for maintaining the top of the stack in an aligned position such that a feed roller means exerts uniform and equal forces on the sheets to provide for accurate and positive feeding of the sheets from the stack. The feeder also includes a sheet locating and guiding means for maintaining the stack of sheets centered on the movable platform and for guiding the sheets as they are fed from the stack.