Ribbon drive for a thermal demand printer

A demand printer of the type used for printing on tickets, tags, pressure sensitive labels and other media, said printer having various components and comprising:

• a structure for supporting and housing said components;
• a power supply circuit for receiving power from an external source and conditioning said power for the operation of said printer;
• input means for receiving command signals related to the operation of said printer;
• control circuit means mounted on said structure and coupled to said input means and said power supply circuit for processing said command signals and generating corresponding control signals for controlling the operation of said printer;
• printhead means mounted on said structure and coupled to said control circuit means for receiving said control signals from said control circuit means and printing indicia onto said media;
• media delivery means operatively associated with said printhead means and coupled to said control circuit means for moving said media to said printhead means in response to said control signals;
• a spring wrap clutch assembly operatively associated with said media delivery means for use with a rotating shaft to maintain a constant tension on a ribbon,
• a coiled spring of said spring wrap clutch assembly having a leg extending away from one end of the coil;
• a collar of said spring wrap clutch assembly having a bore therein for receiving said coiled spring with said leg extending away from said collar, said rotating shaft extending through said coiled spring in said collar and said collar being attachable to said rotating shaft;
• and
• a plurality of ramped teeth positioned around said rotating shaft, each of said plurality of ramped teeth having a sloped surface, said leg of said coiled spring controllably engaging said ramped teeth.