| 摘要 |
A ribbon tensioning device for use in a single pass typewriter and/or printer ribbon cartridge having a supply spool and a takeup spool between which the ribbon is transferred incrementally by a capstan drive assembly, includes first and second arms joined at first ends and mounted for pivotal movement thereat in the cartridge adjacent the ribbon spools. The arms are biased in opposing relation with the free ends of the arms engaging the peripheries of respective spools, each arm exerting a pressure against a corresponding spool to maintain the tension on the ribbon extending therebetween substantially constant throughout the transfer thereof between spools. A high friction material is applied to the arm of the device which engages the supply spool and a low friction roller is mounted on the arm of the device which engages the takeup spool. As the diameters of the spools increase and decrease, respectively, during transfer of the ribbon, the tensioning device pivots correspondingly to maintain the force provided by the arms substantially constant and as such to maintain the ribbon tension substantially uniform.
|
