IBM Selectric - Page 42

To insure that the latch is parallel to the sleeve, it
should be
ad justed in the following manner:
a. loosen the two latch mounting screws and pull the
latch to the top of its adjustment.
b. Snug the screws IIlightly".
c. Turn the print or cycle shaft in a print direction.
(This will force the cycle clutch sleeve down on
the cycle clutch latch.) Using the Hooverometer,
check the latch he'ight unti I it is correct (#3 scribe
line) .
d. Tighten the cycle clutch 'latch mounting screws.
Keeping the sleeve surface in contact with the latch
surface will insure that the latch wi II remain parallel
to the sleeve while you are adjusting its height.
If the bracket were adjusted too low, the steps would be
at an angle to the I ine of motion of the cycle cl utch
latch. The latch would have difficulty in moving for-
ward to release the dutch sleeve, and a slow, hesitant
operation would result.
Withthebrackettoohigh, the force of stopping the cycle
shaft through the cycle clutch sleeve would tend to cam
the latch forwar.d. A repeat cycle operation could result.
When properly adjusted the top of the latch pivot pin is
1 .546" below the top of the print shaft. This distance
can be measuredwith.the use of the Hooverometer. With
the head of the Hooverometer set at the #3 scribe line,
the head should rest on top of the print shaft with the
handle touching the latch pivot pin (Fig. 88). Be sure
the Hooverometer handle is verti cal. It will be vertical
ifthe base of the handle is centered over the latch pivot
pin.
NOTE: Changing the height of the cycle clutch latch
necessitates a readjustment of the cycle clutch collar,
cycle clutch stop, and the cycle clutch latch restoring
mechanism.
CAUTION: The latch bracket must not become cocked
so that only a corner of the latch plate is stopping the
sleeve. Excessive wear could result. The cycle clutch
sleeve could also be tilted by the latch causing it to
bear against the cycle cl utch pulley hub creating' a
noisy operation.
3. Cycle Clutch Spring and Collar Adjustments
a. lateral position of the spring - loosen the collar
and position the spring left or right on its hubs so
that the right hand end of the spring will clear the
face of the cycle clutch pulley by .004" to .012"
(Fig. 89).
NOTE: This adjustment insures that a maximum
number
of coils of the spring clutch will grip the
driving hub during a cycle operation. Any slip-
page between the driving hub and the spring clutch
could decrease the type head velocity during a
print operation resulting in intermittent I ight impres-
sion. A lack of clearance between the right end
ofthespringclutchand the face of the cycle clutch
2-24
.004" to .012"
Collar Adjustment
Pulley
Cycle Clutch Spring
Sleeve End Play
FIGURE 89. lateral Position of the Cycle
Clutch Spring and Collar
pulley would create a bind causing the spring clutch
to place a heavy torque on the cycle clutch sleeve.
This excessive torque on the sleeve results in a slug-
gish keyboard because the cycle clutch latch link
spring has difficulty in pulling the latch off the
sleeve.
b. lateral position of the collar - position the collar
left or right so that the sleeve will have .010" to
.015" end play.
NOTE: This adjustment insures that there will be
no binds
between the right end of the sleeve and the
cycle clutch pulley. A bind will cause a sluggish
keyboard just as in the previous adjustment.
c. Radial position of the collar - (The position of the
collar directly controls the radial position of the
left hand end of the cycle clutch spring with respect
to the cycle shaft. It determines how much the
spring clutch will be expanded when the cycle
dutch sleeve is latched and the cycle shaft is
in its rest
position.) Adjust the collar so that when
a
zero tilt, negative-five rotate character is hand
cycled the cycle clutch spring will begin to slip
(expand) when the cycle shaft is 1/16" to 3/32"
from its rest position measured on the surface of
check ratchet (Fig. 90).
1/16" to 3/32"
Note: The Positive Cams Are
Almost Horizontal When The
Cycle Clutch Is Latched.
FIGURE 90. Radial Position of Cycle Clutch Collar