IBM Selectric - Page 12

Ifthe bracket were adjusted too low, the steps would be
at an angle to the line of motion of the cycle clutch
latch. The latch would have difficulty in moving for-
ward to release the clutch sleeve, and a slow, hesitant
operation would result.
With the bracket too high, the force of stopping the cycle
shaft through the cycle cl utch sleeve would tend to cam
the latch forward. 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 measured with 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. 28). Be sure
the Hooverometer handle is vertical. It will be vertical
if the base of the handle is centered over the latch pivot
pin.
113 Scribe Line
Hooverometer Handle --"""""
Latch Pivot Pin
FIGURE 28. Cycle Clutch Latch Bracket Adjustment
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 tk
sleeve. Excessive wear could result. The cycle clutch
sleeve could also be tilted by the latch causing it to
bear against the cycle clutch pulley hub creating a
noisy operation.
3. Cycle Clutch Spring and Collar Adjustments
a. Lateral position of the spring - Loosen the .col iar
and position the spring left or right on its hubs so
that the right hand end of the spring wi II clear the
face of the cycle clutch pulley by .004" to .01211
(Fig. 29).
10
NOTE: This adjustment insures that a maximum
number of coi Is of the spring cl utch wi II gri p the
driving hub during a cycle operation. Any slip-
page between the driving hub and the spring clutch
could decrease the typehead velocity during a
print operation resulting in intermittent light impres-
sion. A lack of clearance between the ri ght end
of the spring cl utch and the face of the cycle clutch
pulley would create a bind causing the spring clutch
TO place a heavy iUI~ut: 011 the cyclE clutch :;!cc'.'e.
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.
Sleeve
Collar Adjustment
Pulley
Cycle Clutch Spring
SI eeve End Play
FIGURE 29. Lateral Position of the Cycle
Clutch Spring and Collar
b. Lateral position of the collar - position the collar
ieft or right so that the sleeve will have .010" to
.015" end play.
I'H)lE: This adjustment insures that there will be
no bi nds
between the ri ght end of the sleeve and the
cycle clutch pulley. A bind will cause a sluggish
kt /board just as in the previous ad justment.
c. Radial position of the collar - (The position of the
collar directly controls the radial position of the
left hand end of the cycle cl utch spring with respect
to the cycle shaft. It determines how much the
spring clutch will be expanded when the cycle
clutch 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 posit,ion measured on the surface of
check ratchet (Fig. 30).
This adjustment is difficult to observe at the check
ratchet. A 1/16" to 3/32" rotation of the cycle
shaft wi II cause the print shaft gear to turn approxi-
matey one tooth. The adjustment can easily be
read at the print shaft gear by the following method.
1. Hand cycle a zero tilt, negative-five char-
acter until the cycle clutch begins to slip.
2. Pencil mark the print shaft bearing in line with
a tooth on the gear.