Abstract: An ink ribbon cassette includes a supply side ribbon spool, a take-up side ribbon spool, a cassette case containing therein the supply side and take-up side ribbon spools and pivotably supporting at least the take-up side ribbon spool through a lever member and having an opening through which an outside feed tooth may mesh with the take-up side ribbon spool. A support portion provided in the opening for contacting the peripheral surface of the take-up side ribbon spool prevents the take-up side ribbon spool from protruding outwardly, and a biasing device impart a rotational force to the lever member so that the take-up side ribbon spool is urged against the support portion.

Abstract: An ink ribbon cassette with two projecting arms between which an ink ribbon is held exposed for printing. The cassette has a positioning slit in one of the arms, extended perpendicular to the running direction of the ink ribbon, and two side fixing projections. The former fixes the cassette in the running direction of the ribbon while the latter fix the cassette in the vertical direction, thus securing improved mounting of the cassette and preventing undesirable movement of the cassette.

Abstract: An ink ribbon cassette includes a case, supply side core rotatably held by the case and having an uneven portion in a portion thereof, an ink ribbon wound on the core, a take-up side core rotatably held by the case to take up the ink ribbon, and a spring resiliently engaged with the uneven portion of the supply side core and resiliently pressing the outer periphery of the ink ribbon wound on the supply side core.