Carrier Return Mechanism (New Style) - IBM Selectric Manual

·005" To .015"
/
--...
"-
I
~
\
I
Latch Held Even
Margin Rack
\
\2j
With The Keeper
Held To The
Corner
\
Left
'-....
.../
FIGURE 140. Clutch Unlatching Adjustment
NOTE: Should the clutch fail to properly latch (on
machines equipped with the Old Style margin rack) after
the clutch unlatching adjustment has been completed,
check the margin rack eccentric adjustment which is
located in the Margin Control section. The eccentric
may
be
holding the rack too far to the left restricting
the margin rack motion thereby reducing the amount of
bite that the latch may take on the keeper.
10. Torque Limiter - The torque limiter should transmit 1 to
2
pounds pull on the carrier as the carrier is unlatching
the clutch at the left margin.
If a spring scale is available, the adjustment may be
checked by holding against the carrier with the push end
of the scale and allowing the carrier to slowly unlatch
the clutch at the left margin.
If
no scale is avai lable, the torque may
be
estimated by
holding the carrier whi Ie the clutch is engaged. The
torque I imiter should sl ip readi Iy yet rettJrn the carrier
positivelywithout any hesitation when the carrier is re-
leased.
The adjustm€:1t is made by adjusting the eccentric stud
in the torque limiter hub. If sufficient adjustment is not
avai lable at the eccentric, the torque I imiter spring may
be shifted on the torque limiter hub by positioning the
torque limiter spring clamp.
NOTE: The carrier return clutch arbor should have an
end play of .004" to .006" between the torque limiter
hub and the C-clip on the operational shaft. Adjust the
play by positioning the torque limiter hub laterally on
the shaft. The end play can be adjusted easily if the
torqu-e limiterspring ismoved to the right, off the torque
limiter hub.
49
CARRIER RETURN MECHANISM (NEW STYLE)
Be sure that the print escapement and operational control ad-
justments are correct before attempting the carrier return ad-
justments.
I.
Carrier Return Latch Height - With the carrier return/in-
dex cam at rest, adjust the carrier return latch height
by the adjusting screw on the backplate so that the latch
will passunderthecam follower by .001" to .010" when
it isoperated tothe rear. (For Model
721,
see Fig.
141.
For Model
723
or
725,
see Fig.
142.)
Adjusting Screw
. 00 1" To. 0 1 0 "
i
FIGURE 141. Carrier Return Latch
Height Adjus tment (721)
Adjusting Screw
.001" To .010"
~
-,
FIGURE 142. Carrier Return Latch
Height (723 And 725)