| 摘要 |
<p>A ribbon reverse mechanism for a high-speed line printer having a towel ribbon (12) driven between a pair of spring-loaded spools (14) by gear means (26) coupled to a band drive motor (18) includes an input shaft (30) coupled to the drive motor (18) and having mounted thereon a pair of spaced-apart worms (28) for driving respective gears (32). The gears (32) are each coupled to a wrap-spring clutch, housed within a clutch stop collar (34) having a plurality of teeth (46) engageable with a floating disk (42), to an output shaft (36) coupled to the spools (14). Each of the floating disks (42) are alternately engaged to its respective clutch stop collar (34), thereby permitting the wrap-spring clutch to be wound up, through energization of a coil (48). As one spool (14) becomes full, a ribbon direction sensor outputs a signal indicative thereof to a machine co-processor (40) in order that the active engagement coil (48) may be de-energized, while the inactive engagement coil (48) may be energized for reversing the direction of ribbon travel.</p> |
