– 18 –
When needle thread is excessively long
at the time of using the thick thread, the
end of needle thread held with the nee
-
dle thread clamp is rolled in the seams,
and slip of position of material may oc
-
cur or needle breakage may be caused.
5. OPERATION OF THE SEWING MACHINE
5-1. Sewing
[In case of the mechanical valve pedal]
1) Set a workpiece under the feeding frame
and depress pedal
A
of the pedal switch.
Then the feeding frame comes down.
When the foot is detached, the feeding
frame returns to its home position.
The lowering speed of the feeding frame
changes according to the depressing
amount.
This is used when positioning the parts.
2) When positioning the workpiece and
depressing pedal
B
, the feeding frame
comes down to the bottom and holds the
workpiece.
3) Depress pedal
C
when the feeding frame
comes down to the bottom and sewing starts.
5-2. Needle thread clamp device
By actuating the needle thread clamp device, trouble of sewing at the high-speed start (needle thread
slip-off, stitch skipping or needle thread stain) is prevented, and can reduce gathering (bird's nest) of
needle thread on the wrong side of cloth while keeping stable sewing. When mounting the IP-420,
changeover of motion ON/OFF is performed with
key.
When the needle thread clamp device is OFF, the machine automatically operates at slow-start.
When memory switch No. 35 is "1" (prohibited), the thread clamp does not work. In addi
-
tion,
key is ineffective.
(1) When with thread clamp (motion), use the sewing machine after adjusting the needle thread length
at the start of sewing to 45 to 55 mm. When the needle thread length is too long, the needle thread
end held with the needle thread clamp may be rolled in the seams.
45 to 55mm
1) In case of with the needle thread clamp, the stand-
ard of the length of needle thread is 45 to 55 mm.
• To prevent the thread from slipping off from the
needle eyelet at the beginning of sewing or to
prevent stitch skipping from the first stitch
→
Adjust the length of needle thread longer
within the range.
• To prevent stitch skipping within the second to
tenth stitches from the beginning of sewing
→
Adjust the length of needle thread shorter
within the range.
1)
3)
1. Thread at the start of sewing may be rolled in case of some patterns. When thread is rolled in
even after performing adjustment of use the sewing machine with thread clamp OFF.
2.
Thread clamp failure may occur in the state that thread waste is jammed in the thread clamp
device. Remove the thread waste referring to
"III-1-6. Needle thread clamp device" p.119
.
A
B
C
1)
2)
3)
