IBM Selectric - Page 50

3.
NOTE: It is very important' for each selector latch to
receive the same amount of motion from the latch bai I,
when operated, in order to produce the proper amount of.
motion to the tilt arm link for a desired selection. If
one of the stop lugs is adjusted too low, its respective
latch will reset early under the latch bail producing an
excessive amount of latch clearance for that latch. This
means
that this latch when operated will not receive as
much motion from the latch bail as the other latch will
when it is operated. This condition which is undesirable
causes the band width of the system to increase.
Tilt Arm Motion - Adjust the tilt link up or down on the
tilt arm (Fig. 109) to control the ti It ring motion so that
the tilhing will coarse align the same for a 3-tilt charac-
ter as it does for a zero-tilt character.
In orderto check this adjustment, it is necessary to roughly
home the tilt ring first. To rough home, half-cycle a
zero-tilt character and adjust the right hand tilt pulley
(Fig. 109) so that the tilt detent will enter sl ightly on
therearsideoftheV-shaped detent notch in the tilt ring
when the tilt ring play is removed in the restoring direc-
tion (Fi g. 11 0). As the ti It detent is allowed to seat itsel f,
the rear of the tilt ring should rise slightly. Thisisa
preliminaryadjustment and will require refinement after
the proper tilt arm motion is obtained. .
/
I
-----
/'" ""
/ Rear Tooth .. ,\~
\
\
cycled 3-tilt character will coarse align the same as a
half-cycled O-tilt character. That is, both selections
wi II provide the same rising action to the rear of the tilt
ring as the detent is allowed to seat in the detent notch.
If the O-tilt and 3-tilt coarse align the same, the l-tilt
and 2-tilt selections will also coarse align the same be-
cause of the leverage designed into the system.
NOTE: The right hand tilt pulley lock nut may be left
loose while making the tilt arm motion adjustment, be-
cause a sl ight readjustment of the pulley may be neces-
sary during the ti It arm motion adjustment.
On late level machines the tilt arm I ink has a horizontal
elongated mounting hole where it fastens about the
shouldered screw on the ti It arm and the tilt arm is lightly
spring loaded away from the side frame by a hairpin
spring. The tilt pulley spring is far stronger than the
hairpin spring thus holding the tilt arm against the right
hand end of the elongated mounting hole in the link.
Although this modification has no definite effect on a
ti It operation, its function is to remove any slack that
may appear in the tilt tape. An example is when an
operator changes the typehead she may accidentally tilt
the head causing the tape to slacken.
Tilt
UPPER CASE
Home Position ...
,
LOWER CASE
Home Position
.
-
Ti I t Magnets
1 -t
Tl T2
1 1
Ti It Detent
I
\
\
,
J
/
/
/
Rotate -- -5 -4 -3 -2 ~I· 0 +1
+2 +3 f4 +5
\
Detent Enters Slightly To The ~ear '\
-
",,-'"
FIGURE 110. Rough Homing
Once the print shaft has been prel iminadly timed and the
tilt ring rough homed, all of the following adjustments
that require half-cycling should be done under power so
as to include all the streSses on the system.
When the tilt arm motion is adjusted p~~perly, a half-
2-32
L-Clockwise
r Counterclockwise
2A } Rotate
.
Magnets
2 R 2A
1 R2
R·1
-5 R-5
T = Contact Transferred
E
= Magnet Energized
NOTE: If possible CE should note what
characters are I/O home and which are
latch home
FIGURE
111.