JUKI LK-1941, Engineer'S Manual

Page: 35 / 126

−
30
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藺 Thread spreading failure or
thread trimming failure will be
caused.
藺
If the adjustment value is larger
than the specified one, length of
the remaining needle thread
may be excessively shortened.
藺
If the clearance is smaller than
the specified value, length of the
remaining thread under the cloth
is shortened.
藺 If the clearance is larger than the
specified value, thread does not
come in contact with the hot wire
plate and the thread trimming
failure will be caused.
藺 If there is the electric continuity,
heating of the hot wire plate is
insufficient and the thread
trimming failure will be caused.
藺 Thread spreading failure or
thread trimming failure will be
caused.
◎
Adjusting the moving knife
①
Remove the machine arm, fit the cam installing link to the thread
trimmer cam, turn the hand pulley in the normal rotating
direction, rotate the main shaft, and make the moving knife
travel to its extreme front.
②
Loosen setscrew 笊 , and move the thread trimmer lever
(small) in the direction of the arrow mark to adjust the knife.
◎
Adjusting the hot wire plate
①
Loosen setscrew
笆
and move the hot wire base to adjust the
plate.
②
After adjusting the clearance, check with the tester or the like
that there is no electric continuity between the hot wire plate
and the needle hole guide, and between the hot wire plate and
the throat plate.
③
Adjust the tightening torque of setscrews 笆 to 98 to 147 N
•
cm
(10 to 15 kgf
•
cm).
④
Confirm that the hot wire plate comes in close contact with the
insulation sheet. If not, loosen setscrews
3
, and adjust by
moving the hot wire plate. (When loosening setscrews
3
,
perform the work of
①
again.)
◎
Replacing the hot wire plate
①
Remove setscrews
3
, and remove the hot wire plate.
②
Replace the insulation sheet.
③
Replace the hot wire plate, and tighten setscrews
3
.
④
Adjust the tightening torque of setscrews
3
to 48 to 98 N
•
cm(5 to10 kgf
•
cm).
⑤
Perform the adjustment of the hot wire plate. (Refer to the
aforementioned “
◎
Adjusting the hot wire plate”.)
* When it is used for a long period of time, the insulation
sheet is deteriorated. Replace the insulation sheet together
when replacing the hot wire plate.
The operating timing of the moving knife is as described below
when performing the hook adjustment, adjusting the position of
the thread trimmer cam, and standard adjustment of the
aforementioned 6) and 8).
①
The top end of the moving knife is positioned nearly to the
center of needle when rotating the main shaft with the hand
pulley in the normal rotating direction and the top end of the
thread drawing section of the thread drawing spring of the
lubrication hook (extreme periphery of the hook) is 5 ± 1 mm
from the center of needle.
②
When the top end of the moving knife is not positioned as shown
in the fugure on the left, perform again hook adjustment,
adjusting the position of the thread trimmer cam and the position
of the moving knife.
Adjustment Procedures Results of Improper Adjustment