Patent ID: 6691874
Filing Date: 2004-02-17
Classification: B65H

Abstract:
A sheet stacking device, comprised of:a sheet support bed comprised of a plurality of side-by-side rollers, each of said rollers being freely rotatable about a respective roller axis; a support bed drive assembly for moving said sheet support bed in a predetermined direction along a closed path, said path having an upper horizontal run and a lower horizontal run and being dimensioned such that a gap exists between a leading end and a trailing end of said sheet support bed, said gap moving along said path as said sheet support bed moves along said path; a roller control assembly operatively engaging said rollers for selectively controlling rotation of select ones of said rollers about the respective roller axis of said select ones of said rollers; and a controller for selectively and sequentially controlling the operation of said support bed drive assembly and said roller drive assembly, wherein said stacking device is operable to perform the following operational steps: a) causing said support bed drive assembly to move said sheet support bed to a sheet receiving position on said upper run of said path; b) causing said roller control assembly to allow said rollers to rotate freely to receive a sheet to be stacked on said support bed; c) causing said support bed drive assembly to move said sheet support bed at a predetermined speed along said path to move said sheet to a stacking position; d) when said sheet is at said stacking position, causing said roller control assembly to rotate select ones of said rollers in a predetermined direction at a predetermined speed while said support bed continues to move along said path, wherein said select ones of said rollers are operable to convey said sheet in a direction opposite the direction of said support bed at a speed wherein said sheet remains essentially stationary at said stacking position; and e) continuously driving said sheet support bed along said path and continuously rotating said select ones of said rollers wherein said sheet becomes unsupported as said trailing end of said sheet support bed passes under said sheet and said sheet drops through said gap to a stacking location below said upper horizontal run.