IBM 01 Maintenance Manual page 280

MODELS 4 and 5 CUSTOMER ENGINEERING
pulling on the aligning link. Match the clevis pin of the
aligning link with the hole in the back space bell crank.
If this link is too long, the back space may fail because the
escapement pawls are not fully aligned. If this link is too (
short, it may hold the escapement pawls so tightly that
some of them may be prevented from bottoming in the
escapement rack after a back space attempt.
THE BACK SPACE PAWL STOP.
Position the carriage to
rest on the 1 escapement pawl. Operate the back space
cam by hand and, when the rack has traveled approxi-
mately 1-1/2 units to the right, the stop should be locked
in place against the back space pawl ends (Figure 11).
The 1-1/2 units of travel will be indicated when the
8 pawl drops into the rack with 1/2 unit overtravel. Check
the escapement pawl block assembly to insure that the
pawls are square with the escapement rack (Figure 9) ..
Check also to see that the aligning lever bail is straight
and that the guide pin is not bent or loose.
ROTARY BACK SPACE
Adjustment of the rotary back space mechanism should
be carefully checked according to the following procedure.
No, bending or forming adjustments are required or
advised.
THE BACK SPACE PINION GEAR
must mesh properly with
the rack teeth (Figure 13). Adjustments may be made
by removing the ratchet wheel and loosening the screw
which holds the main bracket to the rear rail just over
Clutch Bellcrank
Clutch Pawl Release link
octwates
interlock during corr. return
Remove Ratchet Whee'
and loosen Locking- Nut
to raise or lower Gear Shaft
Figure 13. Rotary Back Space Mechanism
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