JUKI 6100 Technical Manual page 10

4.4
Ribbon
feed
mechanism
A
wide ribbon
which
can be vertically
shifted in three stages
is
used. Either a
single-strike
ribbon
or multi-strike
ribbon
is
used. In the multi-strike ribbon, the
same
part
is
hammered
a
few times while
in
the single-strike
ribbon
the
same
part
is
struck
only once.
The
drive gear
ratio,
which determines the
amount
of ribbon
movement,
is
auto-
matically
set
according to
the type of ribbon
cartridge
being
installed.
1,
Single-strike
ribbon
2.
Multi-strike
ribbon
The
lift
and
fall,
and winding of
the
ribbon are
done by
the
dc motor,
spring
clutches
and
clutch
magnet through the cams.
The
spring clutch
is
used
for
the
ribbon
lift
cam
and ribbon
down
cam.
When
the
ribbon
motor
runs to
put
the
clutch
magnet into operation, a spring clutch
works
to
cause the ribbon
lift
cam
to turn
1/3.
At
this
time, the
ribbon
lift
cam makes
the ribbon
move up and down,
and
the
pawl
of the ribbon
lift
cam
kicks the ratchet
arm
to feed the ribbon.
As
the
motor
runs in
the operate the
ribbon
down
cam,
making
the
ribbon go
down
to
the lowest position.
The
ribbon
down cam
is
activated
at
the
end of
a
print
operation to
allow easy visual
inspection of the
last
print
line.
4.5
Form
feed
mechanism
The
platen
is
driven
by
a
stepping
motor
through an intermediate gear to
accom-
plish
form
feed.
When
moving the platen in reverse,
the stepper
motor
will
move
the platen past the point
where
printing
is
to
be done, then the platen
will
be
moved
forward
to
the print line
and stopped. This
is
down
to help
compensate
for
backlash
between the gears
of the
form
feed
mechanism.
/7TT\
/m
/Ttv\
/m
/Tm
Fig.
4.5
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7
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