IBM Selectric Reference Manual

4.
5.
Tab Rack Brake - Adj ust the tab rack brake so that the
tab
rack will not flip past the rest position when re-
leased from either a set or clear position. The tab rack
must return fully to the rest position when the keybutton
is released slowly. The brake is located just inside the
powerframe at the left end of the tab rack. The brake
shou Id be formed, if necessary, to spri ng load the tab
rack toward the RH si de of the machine.
CAUTION: The index detent lever wi II rest against
the tab rack with the platen removed. Be sure the
lever is clear of the tab rack when the brake adjustment
is checked.
Gang Clear Finger (Ref. Fig. 228A)
a. Adjust the gang clear finger front to rear to obtain
.00111 to .020
11
clearance (Fig. 228B) between its
ti p and the nearest tab stop when a II the tab stops
are set.
FIGURE 228A Gang Clear Finger
FIGURE 228B. Gang Clear
b. Form the end of the gang clear finger to obtain a
minimum
of .00111 clearance (Fig. 228B) between
the gang clear finger and the tab rack tube. Check
for interference between the top of the gang clear
finger and the underside of the tab set spring.
c. Check for a minimum of .00111 clearance (Fig. 228B)
between lugs on the rear of the escapement
and backspace pawls and any set tab stop when the
tab rack is rotated to the clear position and the
pawls removed from the rack, as in a carrier return
operation. If this clearance is not present, re-
check tab rack position and pawl clearance ad-
justments.
2-76
1.
2 .
NOTE: It will not always be possible to clear a
sing
Ie tab stop when two or more adjacent tab stops
are set. The gang clear finger can be moved right
or left slightly to insure positive clearing of de-
sired stop. The tab stop directly to 'the left may al-
so be cleared or partially cleared.
TABULATOR MECHANISM (LATE STYLE)
Interlock Switch (Fig. 229)
a. With the torque bar in the rest position, form the
horizonta Ilug on the left end of the tab torque bar
so that .010
11
- .015
11
exists between the tab switch
trigger and its latching surface.
b. Tab interlock swi tch bracket. Adjust by its mount-
ing screws for two conditions.
1. Up and down so that the torque bar is vertical
in the rest position. Be sure that torque bar
linkage does not interfere when making this
adjustment.
2. Front to rear so that .00111 - .00211 clearance
exists between the tab switch trigger and the
rear edge of the tab torque bar extension.
c. Adj ust the switch by it s mounting screws for .002"
to .008
11
clearance between the switch plunger
and trigger.
Horizonta I
--
T orqu e Bar ':":4~b§tb~n==~~I:=
FIGURE 229. Tab Interlock Switch
Escapement Bracket (Fig. 143) - Observe the .001" -
.002 II clearance between the escapement bracket and
the tab torque bar. If this adjustment is incorrect, all
escapement adjustments should be made before proceed-
ing with the tab adjustments.
NOTE: This adjustment should be checked with the
overthrow stop and retaining plate removed from the
printer. Leave the overthrow stop and retaining plate
off for the following adjustments.

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