IBM Selectric - Page 75

5. Cam Check Ring - Adjust the cam check ring eccentric
(Fig. 162A) so that a clea"rance 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. 162B). Keep the high part of the eccentric rad-
ia lIy outward. The check ring mounting screws must be
loosened
before the adjustment can be made.
Adjust Eccentric
A. LEFT SIDE OF CAM
Cam Pawl
B. RIGHT SIDE OF CAM
FIGURE
162. Cam Check Ring Adjustment
The
adjustment insures that the pawl will clear the rat-
chet and that the check ring wi II latch positively at
the completion of each cam operation.
Stop Pad
FIGURE
163. Clutch Release Arm Stop Pad
7. Clutch Release Arm (Fig. 164) - The lug at the bottom
of each clutch release arm should be formed so thot it
clears the interposer lug by .025" to .035" on Carrier
Return, Index and .035
11
to .045
11
on Tab, Backspoce,
and Spacebar. On 767 printer BS adjust clearance for
.040" ,to .050
11
•
NOTE: The interposers and cams must be latched when
the adjustment is observed.
Insufficient clearance wi II cause the cams to be re'-
leased too
early in the rearward travel of the interpo-
serSi consequently the operational latch involved will
not have sufficient bite on the cam follower lever as it
is operated down at the rear. The operationa I latch
may slip from beneath the cam follower and result in
an incomplete operation. Excessive clearance could
allow the interposer to reach the limit of its travel be-"
fore the cam is released.
6.
Clutch Release Arm Stop Pad (Fig. 163) - 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 3/4
bite on the latching surface of the clutch wheel. This
should
be observed from the rear of the machine.
:== Form Lug
~'"
.035
11
to .045" Tab,
B.S. Space
.025" to .035" C.R.,
Index .040
11
to .050"
Make certai n that the interposers are latched forward
and are not in contact with the clutch release arms
when observing this
adjustment.
NOTE: On long carriage machines the operational
clutch wtchet must be posi ti oned la'tera lIy on the oper-
ati ona I shaft so that each clutch re lease arm wi II take
an equal lateral bite on its respective clutch wheel.
This insures that neither clutch release arm can slip
sic!:-""ays off its respective clutch wheel causing an un-
wanted cam operation. This condition is most serious
on
the carrier return/index cam as it will cause an in-
dex operation to occur each time the cam is released.
2-57
(767 B.S.)
FIGURE 164. Clutch Release Arms
NOTE: The clearance may be judged with the use of
the push end of the large spring hook. The end of the
spring hook is approximately .035
11
thick.
8. Interposer Restoring Bail - Form the lug at each side of
the restoring bai I so that the interposers wi" be restored
forward
.010" to .030" past the latching point (Fig.
165) when either cam is operated. Be sure to check
the interposers at each si de and form the I ug on the
side being checked.