130524
4. Bobbin case checking device
(1) Adjusting the sensor
(2) Position of the bobbin case checking arm
5. Detection of stitch skipping and detection of no bobbin-thread
1
Standard adjustment
0.2mm
Standard adjustment
Top end
Standard adjustment
2
No bobbin-
thread
detection
sensor
2
1
Stitch
skipping
detection
sensor
4
3
Adjustment procedures
1. As a guide, a clearance of 0.2 mm
should be provided between the
sensor slit plate and the sensor.
It should be noted that the sensor
should not come in contact with
the sensor slit plate.
Adjustment procedures
1. Discharge air.
2. Remove the bobbin case from the
hook. The slit in the top end of the
cylinder should be pushed against
the bobbin case shaft when the
cylinder is retracted the most.
3. Turn the power ON.
4. Load the bobbin case in the hook.
The sensor should be turned ON
with the top end of the cylinder
pushed against the bobbin case.
5. Remove the bobbin case from the
hook. The sensor should be turned
OFF when the cylinder is retracted
the most.
Adjustment procedures
1. Turn ON the power to the sew-
ing machine to activate the sen-
sors.
2. Loosen screws 1 and 2 shown
in the fi gure until they can be
moved.
3. Adjust screws 1 and 2 so
that the stitch skipping detec-
tion sensor light illuminates the
center of refl ective seal 3 and
so that the no bobbin-thread
detection sensor light does not
illuminate the needle but illu-
minates the center of refl ective
seal 4 .
– 12 –
Results of improper adjustment
Faulty detection can occur.
Sensor failure is caused.
Results of improper adjustment
Faulty detection can occur.
Results of improper adjustment
Faulty detection can oc-
cur.