GB1364741A - Inking ribbon transport mechanism - Google Patents

Abstract

1364741 Feeding webs INTERNATIONAL BUSINESS MACHINES CORP 9 June 1972 [23 June 1971] 26927/72 Addition to 1309583 Heading B8R [Also in Division B6] A page-width ink ribbon 16 is fed in either direction between two take-up rolls (2, 4, Fig. 1) which are driven alternately by an inkribbon actuated reversal mechanism comprising a two-armed lever (46, Fig. 2) operating a switch (50). The rolls (2, 4) are rotatably and pivotally mounted on a fixed plate (6) and are rotatably and pivotally mounted in a pivoted plate (8). When plate (8) is pivoted about axis (10), the rolls (2, 4) are skewed with respect to each other so that transverse registration of the ink-ribbon can be achieved, as described in Specification 1,309,583 (see Division B6). When one or other of the drive motors (110, 112, Fig. 9) for rolls (2, 4) is energized with half-full voltage, it acts to tension the ribbon being wound on the other roll by the other motor energized with a fullvoltage. Transverse detecting.-The skewing operation of the rolls (2, 4) is controlled by a sensing finger 20, Fig. 4, and an arm 38 periodically moved to intersect the path of the ribbon 16 to sense the presence or absence of the ribbon, in a similar manner to that described in Specification 1,309,583. If the ribbon is under the arm, the movement of the ribbon causes the finger 20 to pivot which in turn allows the arm to drop. This sets either drive pawl 94 or 90 to engage one or other of the eeth 56 or 58 of a continuously rotating ratchet 54. This rotates a cam 32 through 180 degrees which moves a cam follower 34 attached to pivoted plate (8) so that the skew of the rolls is reversed. There are two pawls 90 and 94 so that one drives when one roll is winding and the other drives when the other roll is winding. When the ribbon has shifted from under the finger 20, the sensing arm again sets a drive pawl 90 or 94 and rotates the plate (8) back to the starting position by turning the cam 32 through 180 degrees. A cam 60 with diametrically opposed lobes 62, 64 raises the finger 20 via the sensing arm 38 to periodically move the finger 20 out of the path of the ribbon.