Ink ribbon cassette and loading mechanism therefor

Claim 1

An ink ribbon cassette, comprising: a cassette body having a rear face, opposing side faces, a top face, a bottom face, a pair of guide arms each extending in generally parallel configuration to an extreme of said guide arms; an ink ribbon contained in said cassette body, said cassette body and said guide arms guiding said ink ribbon therein with a portion of said ink ribbon extending between said extremes of said guide arms to expose said portion to the exterior of said cassette body for printing; a ribbon feeding member comprising a rotation shaft extending between the top face and the bottom face of said cassette body, the ribbon feeding member being rotated by power transmitted from the exterior thereof and having at its periphery an engaging portion which engages said ink ribbon; a take-up spool for taking up said ink ribbon; a swing member on end of which is rotatably supported on a rotation shaft within said cassette body and the other end of which is free and rotatably supports said take-up spool; biasing means for imparting a rotation force to said swing member so that said take-up spool is urged against said ribbon feeding member; a pair of inclined surfaces formed in said bottom face of said cassette body, inclined with respect to said bottom face, and terminating in a positioning slit extending in a direction essentially perpendicular to the direction of said ink ribbon portion extending between said extremes of said guide arms and essentially parallel to said guide arms; a fixing projection formed on each opposing side of said cassette body; and a positioning projection formed on said rear face of said cassette body opposite one of said guide arms; wherein said positioning projection is provided opposite one guide arm associated with said positioning slit, and wherein said positioning slit, said rotation shaft of the ribbon feeding member, and said positioning projection are arranged substantially in a straight line.