IBM Selectric - Page 57

The upright lug of the tab latch may be formed with the
3" screwdriver by using it as a lever through the hole in
the escapement bracket (Fig. 164). If excessive forming
is
required, recheck and refine the adjustment of 'the tab
lever pawl.
FIG URE 164. Pawl Clearance Adjus tment
4 . Tab Lever Linkage
a. For the best leverage, the tab keylever I ink should
be adjusted for a rest position clearance of 1/8" to
5/32" between the powerframe and the long arm of
the tab bellcrank (Fig. 165).
b. Forminimum lost motion adjust the tab bellcrank so
that a rest position clearance of .001" to .006" exists
between the tab torque bar and the I ug of the tab
lever trigger (Fig. 165).
NOTE: After completing the adjustments, be sure
that the tab lever wi II latch easi Iy at any position
of the carrier. If the tab lever does not latch be-
fore the keylever has been completely depressed, a
refinement of all previous adjustments is necessary
to reduce lost motion in the system.
CAUTION: Be sure that the tab lever overthrow
stop does not interfere with the latching of the tab
lever. It should be loosened and moved to the rear
if necessary.
56
Tab Lever Trigger /_- -. Torque Bar
___ I~i)
- ',_ 1
1
//.
001
" To
~~.00611
1/8" To 5/32"
5.
6.
Tab Bellcrank
FIGURE 165. Tab Linkage Adjustment
Tab Lever Overthrow Stop - Adjust the 'stop forward or
back so that .005" to .015" clearance exists between
the lug of the tab lever trigger and the overthrow stop
when the tab lever is latched to the rear (Fig. 166).
Adjustment of the overthrow stop prevents a hard de-
pression of the keylever from throwing the tab lever to
the rear into the unset tab stops.
.005" To
Tab
Lever Latched
FIGURE 166. Tab Lever Overthrow Adjustment
Tab Rack - Setatabstopandbackspaceonetime. Slowly
depress the tab keylever whi Ie holding the carrier to pre-
vent it from moving to the right. A clearance of .005"
to .020" should exist between the tip of the tab lever
pawl and the tab stop as the tips are in line with each
other{Fi g. 167). Adjust the tab rack bushing at the right
end of the tab rack to obtain this condition. The lock-
ing plate, which holds the bushing in position, must be
loosened before the adjustment can be made.