IBM Selectric Manual

18. Lockout Bail Link -Adjust the link so that the bail is
centered under the lug of the cycle clutch pawl with the
switch in the OFF position (Fig. 19). Be sure that the
lockout bai I bellcrank has equal over-center motion.
19. Lockout Bai I Bracket - With the switch in the OFF posi-
tion' adjustthe bracketatthe leftend of the lockout bail
vertically to provide .005" to .010" clearance between
the bai I and the lug on the cycle clutch latch pawl
(Fig. 19).
20. Keyboard Lock Bellcrank Link - Adjust the link so that
the bellcrank is fully bottomed in the selector compen-
sator without choking off the action of the lockout bai I
(Fig. 19).
21 . Operational Lockout Shaft Link - With the switch in the
OFF position and the operational lockout shaft I ink fully
forward, adjust the clevis to match the keyboard lockout
bail position (Fig. 19).
The link is restricted in its forward movement when the
tai I of the I ink contacts the top of the shaft. This pre-
vents the link from toggling past center as the switch is
turned OFF.
CAUTION: Be sure the flat of the shaft is forward when
making the adjustment. Be sure the switch lever operotes
easily after making the adjustment. Be sure that the
operational keys are positively locked and unlocked in
the two switch positions. Be sure the keyboard lockout
bail is not restricted by the adjustment.
SHIFT MECHANISM
1. Shift Cam Back-Up Roller - Adjust the back-up roller
eccentric leftor right so that .001" to .004" of the cam
bearing extends beyond the cam (Fig. 20). The eccentric
should be kept in the bottom hal f of its orbit.
Adjust Back-Up
Roller Eccentric
FIGURE 20. Shift Cam Back- Up Roller Adjustment
7
2.
If the bearing did not extend beyond the cam, the shift
clutcharborcouldrubagair,stthe cam and create a noise
as we II as a drag on the cam when the cam was stationary
Two problems could be created by having too much of the
bearing extending beyond the cam. A gap would exist
between the cam and the shift clutch arbor. This could
allow a coil of the shift clutch spring to wedge into the
gap and lock the machine. If the back-up roller were
excessively far to the left, the cam would be forced to
the left at the rear causing it to cock and bind at the
pivot.
The set screw for the back-up roller eccentric is acces-
si ble through a hole in the cam with the cam in the lower
case position. The shift clutch mechanism including the
arbor should be removed in order to best observe the ad-
justment. Be sure that. 002" to .004" end play exists in
the operational shaft when the arbor is replaced.
CAUTION: Anychange in the position of the back-up
rollerdirectly affects the typehead homing and the shift
arm motion adjustments. Be sure to recheck these adjust-
ments.
Shift Clutch Spring Retaining Plate - Adjustthe retaining
plate attached to the shi ft cam (Fig. 21) to satisfy the
following condition. With the machine turned OFF and
the shift cam detented, the shift clutch ratchet should
rotate 1/16" to 3/32" when the shift release arm releases
the ratchet. The rotation can be observed relative to the
shi ft interlock (Fig. 23). The distance from the center
of one ratchet tooth to the next is 3/32" .
The adjustment ofthe retaining plate determines how much
the clutch spring wi II be expanded when the shift mech-
anism is at rest. Expanding the spring too much may
cause failure of the cam to reach the detented position,
because the spring would be expanded too soon. Insuf-
ficient expansion would allow the clutch spring to drag
when at rest creating a load on the motor and on the shift
release mechanism.
Clutch Spring
Retaining Plate
FIGURE 21. Shift Clutch Spring Retaining Plate

IBM Selectric Specifications

General

Type	Electric typewriter
Introduced	1961
Keyboard Layout	QWERTY
Carriage Return	Electric
Manufacturer	IBM
Printing Technology	Typeball (golf ball)
Power Source	AC Power
Power Supply	120V AC