Harmonic-Drive Ribbon Stuffer for Impact Printers

This paper describes a harmonic-motion ribbon-stuffing device for impact printers, which maintains a consistent placement pattern for large-capacity (120 yards) endless-loop fabric ribbons. The ribbon is uniformly placed into a cavity by eccentric drive rolls that ensure alternate ribbon switching due to the geometric relationship of drive rolls and strippers. The ribbon is positively placed in a manner much like a fixed-displacement drive, thus differing significantly from the principle used by existing ribbon packers, which achieve ribbon placement by balancing the difference in net driving force against the buckling resistance of the ribbon.