Improved ribbon feed and lift mechanism for a typewriter

摘要

in a daisy wheel (17) or rotary print wheel typewriter, a single motor (47) (stepper motor) is employed to accomplish both ribbon lift and feed for typewriter ribbon (16) and correction ribbon (30) loaded in a cartridge assembly (15). A single motor drive moves a cartridge assembly support about an axis (41) to present either the typewriter ribbon or the correction ribbon to the print point at the print line. In the first portion of the arc that the cartridge assembly moves up for normal typing with the typewriter ribbon, only the feed ratched (65) for the typewriter ribbon is engaged into drive pawl (81). Alternatively, when the rotation is greater, to present a correction ribbon at the print line, the added elevation of the cartridge assembly causes the correction ribbon ratchet (66) with drive pawl (82) together with disengagement of the ratchet (65) from pawl (81) through camming effect due to ratchet (66), pawl (82) and link (85). When the cartridge assembly is brought back down about axis (41), the only pawl engaged ratchet is driven thus driving the corresponding ribbon by one feed increment.