Cassette tray assembly for feeding sheets of different basis weight

Abstract

A sheet stacking and lifting cassette tray assembly for reliably and effectively feeding sheets of different basis weight for use in a reproduction machine. The sheet stacking and lifting cassette tray assembly includes a cassette frame including a frame floor, and frame side walls; a plurality of sheet stacking and lifting subassemblies mounted within, and to, the frame side walls for applying selectable values of sheet lifting normal forces against a sheet feedhead. Each sheet stacking and lifting subassembly of the plurality of sheet stacking and lifting subassemblies includes a pivotable stacking and supporting plate, and a set of springs having a spring rate for providing a normal force having a particular value for lifting a stack of sheets. The sheet stacking and lifting cassette tray assembly also includes a selecting device for engaging a first number of the plurality of sheet stacking and lifting subassemblies so as to prevent the first number of the plurality of sheet stacking and lifting subassemblies from applying a normal force for lifting, thus varying a number of the sheet stacking and lifting subassemblies applying a normal force to a stack of sheets of a given basis weight, and thereby enabling reliable and effective feeding of sheets from such stack without sheet feeding miscues.