Print wheel cartridge

A printwheel cartridge for use in a printer having a carriage including printwheel release means thereon, said cartridge comprising:

• a printwheel having a hub, and a pair of substantially parallel flat portions on said hub, said printwheel being housed within said cartridge for protection during handling and for being rotationally oriented for usage,
• a pair of opposed abutment means each having a driving face for acting on said hub, one abutment means drives said printwheel in one direction insertion and the other abutment means drives said printwheel in a direction opposite to said one direction during removal of said cartridge from said carriage, the distance between the driving faces of said abutment means being slightly greater than the diameter of said hub for allowing free rotation of said printwheel within said cartridge during operation of said printer, and
• spring retaining means having a pair of arms biased radially toward said printwheel hub for engaging said flat portions to prevent rotation of said printwheel, said arms extending substantially parallel to said one direction for allowing said cartridge to slide relative to said printwheel in order that the driving faces of said abutment means may engage said hub, and each of said spring arms includes detent means for receiving said printwheel release means for moving said arms away from said hub to free said printwheel for rotation within said cartridge.