Ribbon cartridge

A reel-over-reel ribbon cartridge comprising

• a housing having a base
• a reel shaft mounted on said base with its axis perpendicular thereto
• a ribbon supply reel rotatably mounted on said reel shaft with one side thereof adjacent said base for providing a supply of fresh ribbon wound thereon
• a ribbon takeup reel rotatably mounted on said reel shaft on the opposite side of said supply reel for providing a takeup of used ribbon
• ribbon guide means for guiding said ribbon from said supply reel to said takeup reel, said ribbon guide means including four shafts mounted on said base, a first shaft receiving said ribbon from said supply reel having its axis tilted away from said supply reel, said remaining shafts being mounted on said base with their axes perpendicular thereto, and
• ribbon driving means positioned adjacent to said takeup reel including
• a drive shaft rotatably mounted on said base with its axis perpendicular thereto and spaced from said reels and having a drive pulley mounted thereon in the plane of said takeup reel
• a pair of idler shafts mounted on said base with their axes perpendicular thereto and on opposite sides of said drive pulley and said takeup reel, said idler shafts having rotatable idler pulleys mounted thereon in the plane of said takeup reel, and
• a normally stretched tensioned elastic endless belt trained around said drive and idler pulleys and engaging an arcuate portion of the outer surfaces of the ribbon of said takeup reel for moving said ribbon from said supply reel to said takeup reel in response to rotation of said drive shaft, said belt engaging an increasing arcuate portion of the outer surface of said ribbon and moving said ribbon at a substantially constant rate as its diameter on said takeup reel increases during use of said cartridge.