Printing ribbon mechanism

Claim 1

IN A PRINTING MACHINE HAVING A GROUP OF TYPE ELEMENTS ARRANGED IN SIDE BY SIDE RELATION, MEANS FOR GUIDING A RECORD MEDIUM PAST SAID TYPE ELEMENTS, A MACHINE FRAME PART AND CYLICALLY OPERABLE MEANS FOR EFFECTING A PRINTING IMPRESSION BETWEEN SAID RECORD MEDIUM AND SAID TYPE ELEMENTS; THE COMBINATION COMPRISING A RIBBON HOUSING, MEANS FOR REMOVABLY MOUNTING SAID HOUSING ON SAID MACHINE FRAME PART, A RIBBON SPOOL FOR SUPPORTING A PRINTING RIBBON, MEANS ROTATABLY SUPPORTING SAID SPOOL IN SAID HOUSING, AN ANNULAR FLANGE EXTENDING INWARDLY FROM ONE SIDE WALL OF SAID HOUSING AND COAXIALLY OF SAID SPOOL, SAID FLANGE HAVING AN OPENING THEREIN, A TENSION SPRING WRAPPED AROUND SAID FLANGE, MEANS ADJACENT SAID OPENING FOR ATTACHING ONE END OF SAID SPRING TO SAID SPOOL, MEANS ADJACENT SAID OPENING FOR ATTACHING THE OTHER END OF SAID SPRING TO SAID HOUSING, SAID SPRING NORMALLY MAINTAINING A PORTION OF SAID RIBBON ON SAID SPOOL, AND MEANS FOR FIRST WITHDRAWING SAID RIBBON FROM SAID SPOOL WHEREBY TO LOCATE SAID PORTION INTERMEDIATE SAID TYPE ELEMENTS AND SAID RECORD MEDIUM AND FOR THEREAFTER ENABLING SAID SPRING TO ROTATE SAID SPOOL WHEREBY TO WITHDRAW SAID RIBBON INTO SAID HOUSING.