GB1309583A - Inking ribbon transport mechanism - Google Patents

Abstract

1309583 Ink-ribbon mechanism INTERNATIONAL BUSINESS MACHINES CORP 19 June 1970 [24 June 1969] 29788/70 Heading B6F A page-width ink ribbon 3 is fed in either direction between two take-up rollers 4, 5 which are driven alternately by an ink ribbon actuated reversal mechanism 9. The ends of the rollers 4, 5 opposite the reversal mechanism ends are rotationally mounted to the ends of a twoarmed lever 88. This enables the axes of the rollers 4, 5 to be set at a skew with respect to each other so that transverse registration of the ink-ribbon can be achieved. Mis-register of the ribbon is detected with a lever 64 pivoted to a double linkage mechanism (73, Fig. 6a). The mechanism (73) cyclically moves the sensing lever 64 into the plane of the ribbon. If the lever 64 contacts the ribbon 3, it is tilted over in a direction dependent on the feed direction of the ribbon, thus enabling the linkage mechanism to take a first of two possible positions (Figs. 6c to 6f). If, however, the ribbon has moved transversely away from the vicinity of the sensing lever 64 so that it contacts a stationary guide surface, then the lever 64 remains in an upright position defining the second position of the linkage mechanism (73). If, after a detecting cycle, the position of the mechanism (73) is the same as the previous cycle, the position of lever 88 supporting the rollers 4, 5, is not changed. If, however,-there is a change in the position of the mechanism (73), this results in a pivoting of lever 88 thereby reversing the skew of the rollers 4, 5. Pivoting of the lever 88 is achieved with an eccentric (89, Fig. 4) in one embodiment, and a crank (121, Fig. 7a) in a second embodiment. The reversal mechanism 9 includes a pair of dog clutches 29, 30 which are alternately engaged to drive one or other of the take-up rollers 4, 5 when reversal elements 12a, 12b carried by the ink ribbon 3 contact and move the ends of a two-armed reversal lever 13. When a dog clutch is disengaged, a leaf-spring (61, Fig. 2) fixed to the clutch disc acts against the inner surface of the stationary part of the dog clutch, and therefore brakes the take-up roller, which is acting as a supply roller for the ink ribbon being wound on to the other take-up roller.