Patent ID: 6024682
Filing Date: 2000-02-15
Classification: B65H

Abstract:
An improved sheet folder for folding flimsy printed sheets, with an automatic feedback controlled fold position correction system, comprising input sheet feed rollers, a fold chute with a chute entrance, reversible sheet feeding rollers in said fold chute, fold rollers, a folded sheets output path, and a sensor system for the folded sheets in said folded sheets output path, wherein a sheet to be folded is partially fed into said fold chute by said input sheet feed rollers and a downstream portion of said sheet is engaged in said chute by said reversible sheet feeding rollers and fed further into said chute by said reversible sheet feeding rollers by a selected distance corresponding to a desired fold position for said sheet, and then said reversible sheet feeding rollers are stopped at a selected stopping position relative to said sheet and reversed to feed said desired fold position of said sheet into said fold rollers for folding said sheet with both said reversible sheet feeding rollers and said input sheet feed rollers, and wherein said fold rollers then feeds said folded sheet into said folded sheets output path, wherein said sensor in said folded sheets output path senses the length of folded sheets in said folded sheets output path to provide a control signal for controlling said selected stopping position of said reversible sheet feeding rollers to provide said fold position correction system, wherein said reversible sheet feeding rollers comprise at least two separately transversely spaced and separately servo driven rollers, and wherein said sensor system is a plural sensor array extending transversely across said folded sheets output path to provide skewed fold correction control signals for differently controlling said selected stopping position of said separately transversely spaced reversible sheet feeding rollers.