IBM Selectric - Section 4. Service Index; BACKSPACE

6.
7.
Red Shift Armature Backstop (Fig. 277 & 278) - With
the armature de-energized, position the red shift arm-
ature backstop to obtain .002" to .005" clearance be~
tween the stud and the follower latch slot.
Red Shift Armature
c====_(D_e_~_l=r=g'=1 z~e=d::;) ;;:::==;~
Armature Backstop
Backstop
Adj.
Screw
FIGURE 277. Red.Shift Armature Backstop
Cam Follower Latch
.002
11
to .005"
~~~- Follower Latch
Stud
FIGURE
278. Cam Follower !Latch
Ribbon Mode Contacts (Fig. 279) -
a. Form the O/P so that it lifts the N/C contact by
.005
11
to .008
11
•
Red Shiftr
Armature
Magnet Mtg.
Brocket
N/O Contact
Contact
Mtg.
Bracket
FIGURE 279. Ribbon Transmit Contact Assembly
b. Form the N/O contact so that it clears the O/p by
.020 II to .030 ".
c. Position the contact mounting bracket on the mag-
net mounting bracket so that red shift armature (at
rest) clears the O/P pad by .00211 to .005 II.
Excessive wipe on the N/O contact" may cause failure
of the red magnet armature to latch. When the N/O
poi ni '11akes the pulse to the magnet· is removed. This is
just
before the armature latches. Therefore, we are de-
pending on red armature overthrow to latch the mech-
anism on red ribbon.
2-91
1.
COVERS AND MOUNTS
Top Cover Hinge - The hinge should be adjusted so that
the contour of the top cover matches the contour of the
center cover (Fig. ·280) .
Hinge Make The Adjustment At These Points
2.
3.
JI~I,rl_l;;iic~;)~};{!~j:;~~~1
Adjust At 4 Points
Top Cover
Hinge ---\---- ...... ......,~
FIGURE 280. Top Cover Hinge
Center Cover Latch (Fig. 281) - Position so that the
top cover is latched securely in the closed position.
FIGURE 281. Center Cover Latch
Hinge Spring (Fig. 282) - Position so that the top cover
will be detented and held in the open position.
Make Adjustment Here
~- ---
~
/
/'
/
(~~
----
FIGURE 282.
---
/
/
Hinge Spring