IBM Selectric Reference Manual

LAST COLUMN,CONTACT
1. Last Column Contacts (Fig. 256, Early)
a. Form the NjC support so that the OjP (at rest)
produces a slight rise of the NjC contact.
b. Form the NjO support so that the NjO contact
clears the Ojp by .020" to .030".
c. Position (carri er in next to last space) the contact
actuator on the bellringer bail so that it just touch-
es the OjP ~ When positioning the actuator, all
back lash must be he I d out of the actuator to line
lock bracket linkage.
Bell Ringer Bail
OjP
NjO Contact
Just Touches
FIGURE 256. Last Column Contact Adjustment (Early)
NOTE: To place the carrier in the next to last
space, proceed as follows:
1. Space to the right unti I the right hand margin
setting locks the keyboard.
2. Backspace two spaces.
d. As the carri er moves from the next to last space,
check for the following conditions (Fig. 257).
1. The contact transfer must be complete (and
Slight
Rise
Must
Make
without bounce) within 'one space.
Bell Ringer Bail
Contact Actuator
Must Break
FIGURE 257. Last Column Contact Adjustment (Early)
2-85
2.
2. N/C contact must break.
3. Ojp must lift the N/O contact sufficiently to
insure reliable make.
Last Column Contact (Fig. 258)
a. With the carrier in the next to last space, the con-
tact actuator arm shall be adjusted to give a .010"
to .020" clearance between the switch wire and
the actuator arm with the switch at its re-transfer
point.
b. The actuator arm sha II be adjusted to give a .060"
to .094" left to right clearance between the actua-
tor arm and the formed angle on the switch wire.
c. The contact backup spring sha II be so adjusted that
the actuator arm wi II contact the backup spring
.250" to .312" before it contacts the switch wire.
3. Region Switch (MTjST) - This switch should be adjusted
so that it makes as the bell rings (Fig. 253). The make
of this switch should be 10 to 13 spaces prior to the last
column contact md:ing.
Ojp
Contact
4.
FIGURE 258. Last Column Contact (Late)
Last Col umn
Contact (Late) (Fig. 258.2) - With car-
rier in the last column, the actuator screw shall be ad-
justed to obtain the following:
A. Transfer the switch and have a .010" minimum
overthrow when escaping from the last column and
it wi II re-transfer with a backspace operation.
B. Provide a .005" minimum clearance between the
actuator screw and the switch plunger, with car-
rier in last column.

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