IBM Selectric Reference Manual

5. Carrier Return Shoe - Adjust the carrier return actua-
ting arm bracket left or right so that the carrier return
shoe overlaps the last 3 coi Is on the right hand end of
the clutch spring. Covering the last 3 coi Is insures
that all the coils of the spring will be used in the clutch
operation (Fig. 208).
Shoe Overlaps
Last Three Coi Is
Carrier Return
Actuating Arm Bracket
CClrri er Return
Pinion
Clutch Spring
FIGURE
208. Carrier Return Shoe
6. Carrier Return Clutch Arm - Adjust the clutch arm on
the carrier return clutch arm hub so 'that the formed lug
which mounts the actuating arm stud will be horizontal
when the! machine is at rEist (Fig. 20'9).
Carri er Return
CI utch Arm Hub
Actuating Aml Stud
Clutch ActuatIng Ann
Adjust Clearance For
. 01 5
11
to . 020 II
Clutch
Spring
FIGURE
209. Carrier Return Actuating Arm Adjustment
7. Shoe Clearance - The nylon shoe on the clutch actua-
ting arm should clear the carrier return clutch spring
by .015" to .020" when the machine is at rest (Fig.
209). Adjust the nut on the actuating arm stud to ob-
tain the proper clearance.
NOTE: In no case shQuld the shoe to clutch spring
clearance be less than .015".
8. Overbank Adjustment
a. EarlyStyle -'With the carrier held fully to the left
against the margin stop, a clearance of .003" to
008" should exist between the working surfaces of
the escapement pawl and the escapement rack tooth
(Fig. 210). Adjust the left hand margin rack bush-
FIGURE 210. Escapement Pawl Check
Loosen Margin Rack Eccentric
FIGURE 211. Overbank Adjustment (Early)
The
overbank adjustment insures that the escape-
ment pawl wi II enter the correct escapement rack
tooth when the carrier return clutch is unlatched at
the left margin. The adjustment may b~ observed
from the top with the platen and deflector removed
and the left margin stop positioned toward the
middle of the rack. The overbank may also be Cld-
justed by adjusting the margin rack bushing to clear
the nylon washer on the margin rack by .025" to
.030 II with the carrier resting at the left margin.
The right hand margin rack eccentric should be
loose when making this adjustment (Fig. 212) so
that the I eft marg i n stop wi II be agai nst the stop
latch on the carrier. The .025
11
to .030" compen-
sates for the .022" floating action in the escape-
ment pawl. (The correct adjustment for the marqin
rack eccentric is covered under the Margin Control
section .)
NOTE: Any change in overbank on machines
equipped with this old style margin rack assembly
will directly affect the clutch unlatching adjust-
mente
Carrier Stop Latch
ing
to obtain this condition (Fig. 211). FIGURE 212. Margin Rack Overbank Guide Adjustment (Late)
2-71

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