Ribbon Feed Mechanism
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
Fig. 1 shows the ribbon feed of a typewriter in which the ribbon 1 is loaded in a cartridge 3 having a lower supply roll 5 and an upper take- up roll 7. Ribbon 1 is pulled out of cartridge 3 by nip rolls 9 and 11, roll 9 being driven while roll 11 is movable away from roll 9 to inhibit feed. Ribbon 1 is guided by pins 13 and 15 on arm 17 of cartridge 3 across printhead 19, shown in Fig. 1 in the printing position proximate to a standard platen 21. Ribbon 1 is directed away from platen 21 by idler roller 23 and is held in tension by tension arm 25, having a roller 27 over which ribbon 1 passes. Arm 25 is biased counterclockwise by spring 28 (Fig. 2). Tension arm 25 maintains a range of ribbon tension force, typically 20 to 40 grams, to contribute to stabilization of the forces acting against printhead 19 during printing.