Ribbon drive mechanism

A system for feeding a ribbon in typewriters and similar machines having a frame and a print point comprising:

• a supply spool fixed with respect to the frame carrying a supply of ribbon;
• a ribbon guide fixed with respect to the frame for guiding the ribbon from the supply spool towards the print point;
• a bracket vertically moveable relative to the frame;
• a take-up spool mounted on the bracket for vertical movement therewith and for receiving the ribbon from the supply spool;
• a ribbon guide mounted on the bracket for vertical movement therewith for guiding the ribbon from the fixed ribbon guide toward the take-up spool;
• means for raising the bracket for raising the ribbon to the print point;
• means for incrementally winding the ribbon on the take-up spool for feeding the ribbon relative to the print point including;
• a metering disc (78) mounted on the bracket (26) for vertical movement therewith for rotating the take-up spool (14),
• a feed pawl (82) mounted for movement with the bracket and engaging the metering disc,
• a shaft (104) mounted on the frame,
• a lifting arm (100) pivotably mounted directly on the shaft,
• a first pin (108) for coupling the feed pawl to the lifting arm and located a predetermined distance from the shaft, and
• a second pin (96) for coupling the bracket to the lifting arm for moving the lifting arm in response to the vertical movement of the bracket, the second pin located a distance from the shaft less than the predetermined distance of the first pin from the shaft causing the lifting arm to move the first pin a greater amount than the movement of the second pin for moving the feed pawl relative to the bracket to advance the metering disc for feeding the ribbon relative to the print point.