IBM 01 Maintenance Manual page 252

REFERENCE MANUAL
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MODEL Cl
drive shaft so the left spool is in the feeding position
and the right spool is free to rotate.
To insure positive operation with various ribbon
spools the sensing finger may also be forced to the
left by the rotation of the empty ribbon spool. The
resulting counterclockwise rotation of the sensing
finger cam insures that the wire link will unlatch the
reverse lever.
As the right spool empties, its sensing finger en-
gages a notch in the right-hand ribbon spool allow-
ing the sensing-finger shaft to rotate and position a
pawl between teeth of the drive-shaft primary-cam
(Figure 38). As the drive shaft rotates the secondary
cam, pinned to the drive shaft, climbs the high points
of the now stationary primary cam. This pulls the
drive shaft to the right and engages the right gears
in feeding position. This movement of the shaft is
also transferred to the reverse-lever, latching it un-
der the reverse-lever latch, so as to maintain this
condition.
~.H.
Figure 38.
Ribbon Reverse, Right Spool Empty
Rapid rewind of the ribbon takes place as follows:
Depressing the ribbon rewind keybutton raises the
button link (Figure 39). A formed lug on the rear
of the button link raises the button latch and causes
the rewind lever, part of the same assembly, to pivot
clockwise about its mounting. As the left end of the
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