JUKI AMS-221EN Series Engineer's Manual page 39

Adjustment Procedures
1. Counter knife position
Loosen the counter knife set screw
2. Moving knife position
Loosen the screw
(Caution) Confirm, without fail, that there is a clearance between
the moving knife
the clearance seems to be insufficient (0.5mm or less),
make a fine adjustment within the range of 18.5
to secure a proper clearance.
Adjustment Procedures
1. Turn off the power supply and look for any close contact between the
AT solenoid and the thrust collar
fixed with a concave of 0.5mm on the shaft end plane.)
2. Loosen the three set screws
.
3. Hold the tension releasing pin adjust collar
loosen the nut .
4. Turn the tension releasing pin adjust collar
between the thread tension disk
disc floating)
5. Hold the tension releasing pin adjust collar
Mount the thread tension cap
6. Turn on the power supply and set up the thread tension. Confirm that
the thread tension disk
(Caution) 1. When the tension releasing pin adjusting collar
rotated, the thread section should not be engaged with
the incomplete thread section of the thread tension
releasing pin
tension releasing pin
collar .)
* If the amount of disc floating cannot be adjusted properly under the condition that the
thrusting distance is 4 mm or less, loosen the set screw
(front) in the right-left direction.
Refer to "3.-(21) AT unit connection/disconnection".
2. According to S type, it may be difficult to adjust the amount of disc floating to 1.6
even when the thread release adjusting collar
In such a case, try to turn the thread release adjusting collar
disc floating to 1.1
attracted and loosen the setscrew
C until the link's oblong hole center crosses at right angles with the plunger shaft center
visually. There is no problem in performance and the machine can be used when the disc
clearance of S type stays at 1 to 1.7mm only if adjustments have been made by moving the
abovementioned AT solenoid
to adjust the position.
to adjust the position.
and the needle thread clamp
. (The thrust collar
and remove the thread tension cap
. (Adjustment of thread tension
by means of the set screw
are closed.
. (The thrusting distance of the thread
should be 4 mm or less from the tension releasing pin adjusting
±
0.1mm. After that, turn the AT solenoid
. If
±
0.5mm
shall be
not to let it rotate, and
and adjust the gap
and tighten the nut .
.
is
is rotated because of variation in parts.
of the AT solenoid. Move the AT solenoid
described at left.
– 35 –
Results of Improper Adjustment
o If the clearance is less than
1.0mm, thread may be cut by the
counter knife blade when the
thread is pulled with the moving
knife . In this case, upper and
lower threads are cut into short
pieces.
o If the clearance is more than
1.0mm, the residual thread length
after thread cutting operation be-
comes longer beneath the work.
o If there is interference between
the needle thread clamp
the moving knife , this can be a
cause of breakage in the needle
thread clamp .
Results of Improper Adjustment
o If the amount of disc floating is too
less, the residual thread length
can be changed or shortened
when the thread is thick.
o If the amount of disc floating is too
much, the thread tension discs
cannot close completely and nor-
mal thread tension may fail to be
chosen. This can be a cause of
imperfect sewing.
o If the thread section of the tension
releasing pin adjusting collar
is engaged with the incomplete
thread section of the thread ten-
sion releasing pin
tension releasing pin
damaged.
and adjust the AT link unit
to adjust the amount of
ON to make the plunger
and
, the thread
may be
±
0.1mm
in Direction