Margin Control Mechanism - IBM Selectric Maintenance Manual

11.
Tab Interlock Contact-
a. Form (in circled area) the actuating wire (left or
right) so that it contacts the actuating arm near
the right angle bend (Fig. 174).
b. With the tab interposer released and the Tab/Sp/BS
cam on its high point, position the mounting brack-
et (front to rear) so that the actuating arm overlaps
(.040" minimum) the actuating wire (Fig. 174).
This insures that the actuating wire does not get a-
bove the actuating arm.
Actuating Arm
(Tab Torque Bar)
Overlaps
.040" Min.
Contact
Actuating Arm Contacts
Actuating Wire In The
Area Circled
Actuating Wire
(Form In This Area)
Mtg. Bracket
(Front to Rear Adj.)
FIGURE 174. Interlock Contact (Early)
c. As the tab torque bar restores, position the mounting
bracket (up or down) so that the contact actuating
wire travels .031" to .062" after the contact trans-
fers (Fig.
175).
This is done to insure that mach-
ine vibration does not cause the contact to transfer.
Actuating Arm
==~'OOl.031"
Actuating to
Wire .062"
Rest Position
Mtg. Bracket
FIGURE 175. Interlock Contact
NOTE: During initiation of a tab operation, the
switch must transfer (up position) before the Tab/
Sp/BS cam reaches its high point. Torque bar bounce
must not retransfer the contact whi Ie the tab lever
is latched out.
MARGIN CONTROL MECHANISM
1. Margin Rack Overbank Guide - With the carrier resting
at the left hand margin, adjust the overbank guide (Fig.
176)
left or right on the margin rack to obtai!)
.00
I" to
.005" clearance between the margin stop and the margin
stop latch on the carrier when the margin rack is in its
rest pos.ition (Fig.
176).
When observing this clearance
remove the floating action of the margin stop latch by
pulling the stop latch to the right with a spring hook.
FIGURE 176. Margin Rack Overbank Guide
The adjustment insures that the left margin stop will set
accurately when the stop is slid to the right against the
margin stop latch on the carrier.
NOTE: Machines equipped with an old style margin
rack use an eccentric plate mounted on the right end of
the margin. rack to control the rest position of the rack.
Use the same procedure indicated above to obtain the
.001"
to
.005"
clearance between the margin stop and
the stop latch on the carri er.
2. Margin Rack
2-51
a. Early
1. With all parts at rest, loosen the fluted screw
in the margin release lever and rotate the mar-
gin rack (within the release lever) to a level
position (Fig. 177). Then tighten the fluted
screw.
FIGURE 177. Margin Rack (Early)