IBM Selectric Maintenance Manual page 61

4. Interposer Adjusting Screws - Adjust the interposer ad-
justing screws so that a front to rear clearance of .015"
to .020" exists between all the operational latches and
their respective cam followers, with the exception of
the spacebar latch. The spacebar latch should have a
clearance of .025" to .035" (Fig. 116).
NOTE: Machines which have the carrier return latch-
spring loaded to the rear (under the cam follower) should
be adjusted as follows:
a. Hold the carrier return latc.h to the front against its
interposer (the interposer should be latched at rest).
b. Adjust the interposer adjusting screw for .035" to
.045" between the lotch and cam follower.
c. Release the interposer and proceed with the next
adjustment.
Cam Follower
I.£Itch
Make Adjustment Here
Interposer
FIGURE 116. Interposer Adjusting Screw
NOTE: The operational interposer springs should be
placed in the center hole at the rear of the interposer
(Fig. 116).
The adjustment directly affects the timing between the
cam release and the positioning of the operational
latches under the cam follower. Excessive clearance can
a II ow the cam follower to move down at the rear before
the latch has moved fully under the follower.
The adjustment may be checked after operating the cams
enough to move the cam followers down slightly at the
rear. With the machine on its back the latches can be
pushed against the cam followers to estimate the clear-
ance.
CAUTION: If the cam followers are operated too far
when this adjustment is being checked, the interposer
restoring bail will force the interposers forward slightly
and an erroneous adjustment will result. The keylever
pawl to interposer clearance should be rechecked after
this adjustment.
5. Cam Check Ring - Adjust the cam check ring eccentric
(Fig. 117A) so that a clearance of .003" to .008" exists
between the tip of the cam pawl and the teeth of the cam
ratchet with the cam latched in the rest position (Fig.
117B). Keep the high part of the eccentric radially out-
ward. The check ring mounting screws must be loosened
before the adjustment can be made.
Adjust Eccentric
A. LEFT SIDE OF CAM
B. RIGHT SIDE OF CAM
FIGURE 117. Cam Check Ring Adjustment
The adjustment insures that the pawl will clear the rat-
chet and that the check ring will latch' positively at the
completion of each cam operation.
6. Clutch Release Arm Stop Pad (Fig. 118) - Form the stop
pads so that with the clutch release arm at rest (against
its stop pad) the clutch release arm has a 5/8 to 3/4l:-ite
on the latching surface of the clutch wheel. This should
be observed from the rear of the machine.
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Make certain that the interposers are latched forward
and are not in contact with the clutch release arm when
observing this adjustment.
5/8 to 3/4 Bite
Stop Pad
FIGURE 118. Stop Pad Adjustment