JUKI LU-2810 Series, Engineer'S Manual

Page: 37 / 84

– 25 –
Adjustment procedures Results of Improper adjustment
The safety clutch functions when an excessive load is applied to the
lower shaft or the like during sewing. When the safety clutch func-
tions, the hook will not rotate even if turning the handwheel, and the
lower shaft sprocket wheel
4
only will run idle since the power is
not transmitted to the lower shaft.
o
Resetting procedure
1. Checking the moving part of the sewing machine, and look for
and remove the cause which the safety clutch has functioned.
2. Pressing push button
1
located on the top surface of the ma-
chine bed, strongly turn the handwheel in the reverse direction
of rotation.
3. Resetting procedure completes when the handwheel cannot be
turned with “click”.
o
Adjusting the working torque of the safety clutch
1. Tilt the machine head.
2. Loosen setscrew
2
located at the periphery of lower shaft
sprocket wheel
4
and turn release pressure adjusting pin
3
to
adjust the release torque. After the adjustment, tighten set -
screw
2
to fix release pressure adjusting pin
3
.
* Standard of release pressure
When the direction of the slot in release pressure adjusting pin
3
is located near the places below, the relevant release pres-
sure is obtained.
o
24.5 N • m : Top of tooth of 1st sprocket
o
9.8 N • m : Center of bottom between 2nd and 3rd sprockets
o
5.9 N • m : Top of tooth of 3rd sprocket
Adjustment procedures Results of Improper adjustment
1. Loosen setscrews of the face plate to remove the face plate.
2. Turn the handwheel so that the counterweight
1
faces toward
you.
3. Place the balancer
2
in the position shown in the figure.
At this time, make a clearance so that the balancer
2
do not
interfere with machine frame, top feed changing base
3
and
connecting link
4
.
4. Evenly and securely tighten two setscrews
5
of balancer.
o
Vibration becomes big.
海外講習会用121122 LU-2810(-7)̲EM