JUKI MF-7200D/U45, Instruction Manual, Page: 57 / 260

– 15 –
7. Initial position of the lower thread
trimmer mechanism
When looper thread trmmer
4
s located at ts left-
most poston, the top end of the looper thread trm-
mer has to be spaced 22 ± 1 mm from the center of
needle bar.
8. Adjusting the stopper
Check the leftmost pont wth the pneumatc devce
turned on. Adjustment should be carred out wth the
ar pressure set at 0.5 MPa.
Adjust the poston of stopper
!8
so that a clearance
of 0.3 to 1 mm s provded between looper
@1
and
clamp sprng
!7
when the counter knfe s located at
ts leftmost poston (forward end).
!8
When the needle s postoned at ts upper dead
pont, a clearance of 0 to 0.1 mm has to be provded
between the under surface of looper thread trmmer
4
and the top surface of looper
@1
.
9. Adjusting the height of the lower knife
4
@1
0 - 0.1 mm
A
22±1 mm
4
0.3 - 1 mm
@1
!7
Perform the work with the needle bar at the
highest position when actuating the thread
trimmer mechanism by hand.
Center of needle
bar
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ENGLISH
10. Adjusting the longitudinal position of
the blade point of lower knife
1) Brng the needle bar to ts hghest poston.
2) Adjust so that the blade pont of lower knfe
4
s n the center of the thckness of looper
@1
when the clearance between the rght-hand
edge of looper
@1
and the blade pont of lower
knfe
4
s 9 mm.
3) Loosen nut
@2
, move lower knfe holder
5
to
and fro, and adjust the poston of the blade
pont of lower knfe
4
.
4) After the adjustment, tghten nut
@2
.
Perform the work with the needle bar at the
highest position when actuating the thread
trimmer mechanism by hand.
4
9 mm
5
@2
@1
The safety swtch s nstalled so that the sewng
machne does not start unless the lower thread
trmmer devce returns to ts home poston.
1) Loosen setscrews
@5
.
2) Adjust swtch plate
@6
so that LED of thread
trmmer sensor
@7
lghts up n the state that the
thread trmmer devce s fully returned to ts
home poston.
3) Tghten setscrews
@5
.
Perform the work with the needle bar at the
highest position when actuating the thread
trimmer mechanism by hand.
11. Adjusting the thread trimmer sensor
3
3
@7
@6
@5
@8
@9
Speed of the lower thread trmmer devce can be
changed wth speed controllers
@8
and
@9
of ar
cylnder
3
.
1) When you desre to change the protrudng
speed of lower knfe, loosen the nut of speed
controller
@8
, and turn the adjustment screw.
When you desre to change the returnng speed
of lower knfe, loosen the nut of speed control-
ler
@9
, and turn the adjustment screw.
2) After the adjustment, tghten the nuts of speed
controllers
@8
and
@9
.
･ When the protruding speed of lower knife is
slow, thread trimming failure will be caused.
･ When the returning speed of lower knife is
fast, lower thread clamp failure or uneven
needle thread remaining length will be
caused.
12. Adjusting the speed of lower thread
trimmer (UT45)
Blade point of lower knife is
in the center of thickness of
looper.