Carrier Return (Late Style) - IBM Selectric I/O Manual Of Instruction

in the right hand operational latch bracket at the rear of the
powerframe. The carri er return latch arm strc:ldd les the carri er
return lever (Fig. 145) whi ch is tightly fastened to the same
pivot pin by a bristo screw. The bristo screw tightens against
a flat spot on the pivot pin. An adjusting screw threaded
through the top of the latch arm contacts the top of the hori-
zonta

lug on the carrier return lever (Fig. 145). A spring
between these two pi eces loads them together. When the car-
rier return latch is pulled down by the cam follower, the latch
arm forces down on the carrier return lever c1:lusing the pivot
pin to rotate.
/
\
""
Camer Return
Lever
Carrier Return
Clutch Arm
Carrier Return Latch
Actuating Arm
Carrier Return_--t""""I'T'IIo
Latch Arm
Carrier Return
Latch
FIGURE 145. Carrier Return (15 Inch)
Riveted to the right hand end of the pivot pin and rotating
with it is an arm called the carrier return laf'ch actuating arm.
This arm performs the same function on the I()ng carriage ma-
chines as it does on the short carriage. It rotates the eSCClpe-
ment torque bar (removing the escapement and backspace
pawls from their racks) plus operates the carrier return clutch
latch down to its latched position.
The carrier return lever has a pin that projects to the left into
a forkedarm located on the right hand end of the carrier re-
turn clutch arm pivot pin (Fig. 145). This provides a solid
driving connection between the two pivot pins. Whenever
the carrier return latch is pulled down, the carrier return
clutch arm pivot pin rotates causing the clutch arm to produce
a pull on the heavy spring attached to the carrier return ac-
tuating arm. From this point on the operation is the same on
long carriage machines as on the short carriage.
CARRIER RETURN - LATE STYLE
The carrier return operation remains the same. Parts have been
re-designed to provide easier accessibility for adjustments, and
·will hold these adjustments longer.
The transfer of motion has changed in the operational latch
mechan ism (Fig. 145.
1).
When the carrier return operationa I
latch is pulled down by the cam follower, the latch arm
presses the carrier return lever down. A stud on the
car~ier
return lever fits in a slot of the intermediate latch actuating
arm, andas the lever moves down it rotates the armand pivots
the carrier return clutch latch shaft and clutch latch. As the
carrier return clutch latch moves downward, it rotates the
latch actuating arm which contacts the es~apement torque bar
causing the escapement pawl to be removed from its rack.
Further motion causes the clutch latch and latch actuating
arm to be latched in the operated position.
CR Latch Actuating Arm
Clutch Latch
Shaft
• FIGURE 145.1 Carrier Return (Late)
Carri er Return
Clutch Arm
The carrier return lever also rotates the left-hand operational
pivot pin and the carrier return clutch arm forcing the carrier
return shoe into the spring clutch. The shoe is held in th is
position by the carrier return clutch latch.
The carrier return mechanism remains latched in the active
position' until the carrier reaches the left margin. At that
time, the clutch is unlatched and the escapement pawl is al-
lowed to restore back into the rack.
Carri er-Return Contacts
The carrier return operati on requires two kinds of contacts.
One, the feedback contact is usually called C6. This con-
tact is actuated by the carrier return indexing cam follower
the same as the C5 contact. The second contact is a car-
ri er return interlock contact.
The carrier return interlock contact is mounted to the right
side of the power frame in the upper corner (Fig. 146).
58.1