Automatically continuously variable fold position sheet folding system with automatic length and skew correction

Abstract From the Canadian patent

An improved sheet folder for flimsy printed sheets with an automatic fold position correction system. The folder may have an input sheet feeder a fold chute with a chute entrance, reversible sheet feeding rollers in the fold chute adjacent to the chute entrance fold rollers, a folded sheets output path and a sensor system for sensing the length of folded sheets in the folded sheets output path. A sheet to be folded is may be partially fed into the fold chute engaged by the reversible rollers, and fed thereby further into the chute by a selected distance corresponding to a desired folding position along the sheet. Then the reversible rollers are stopped at a selected sheet stopping position …