IBM Selectric Maintenance Manual page 31

2. Armature Stops (Fig.
35) -
Position the armature stops,
with the armatures manually attracted, to obtain
.003"
to
.007"
between the armatures and yokes.
The adjustment insures that the armature will not touch
magnet core. If an armature does touch a core it may be
held by residual magnetism.
Yoke
~
locking Screws "
Armoture Stop
Armature
Backstop
~~"~~='iI
FIGURE
35.
Armature Stops
CAUTION: When locking screws are loosened to make
the U.C. armature stop adjustment, be careful not todis-
turb the armature backstop adjustment.
3. UC Magnet Assembly - Position so that its mounting
screws are centered in the elongated holes with the hinge
plates parallel with the assembly mounting plate.
4. LC Magnet Assembly - Position as follows:
a. Front to Rear - LC armature (energized) clears the
UC armature (at rest) by .010" (Fig. 36).
This clearance insures unlatching of the upper case
armature.
Armature Energized
FIGURE 36. LC Magnet Assembly (Front to Rear)
2-9
b. Up or Down - UC armature (energized) clears the
LC armature (at rest) by .003" to .006" (Fig. 37)."
When the upper case armature is picked the lower
case armature must be able to snap forward and
latch the upper case armature. If the clearance is
excessive the upper case armature may move far e-
nough to allow a shift to take place. When this hap-
pens the printer wi
II
be in lower case whi Ie the mag-
net assembly is latched in upper case.
Armature Energized
U.C. Magnet
Armature at Rest
.003"
to
.006"
FIGURE
37.
LC Magnet Assembly (Up or Down)
5. Magnet Assembly Mounting Bracket (Fig. 38) - Position
the magnet assembl y mounting bracket (UC armature ener-
gized) so that the release arm clears the shift ratchet
lug by .005" to .015".
Shift Release Arm
\U.C. Armature
(Energized)
Mtg. Bracket
FIGURE 38. Magnet Assembly Mounting Bracket