Adjusting The Thread Trimming Device - JUKI DU-1481 Series Instruction Manual

4-10. Adjusting the thread trimming device

WARNING :
To protect against possible personal injury due to abrupt start of the machine, be sure to start the
following work after turning the power off and ascertaining that the motor is at rest.
1. The structure of the thread trimming device of this sewing machine is as shown in the
figure given below.
Thread
guide
Counter knife
Moving
knife
Thread trimming
lever
ⓐ ⓑ
Counter
knife
Thread trimming
Return
cam crank, left
spring
Shaft sleeve
87.5 mm
Thread trimming
cam
Return spring
Thread trimming
cam crank, left
Moving
knife
Thread trimming
cam crank, right
❶
❷
Base of solenoid Thread trimming solenoid
connection link
Thread trimming cam
crank, right
2. Adjusting the counter knife and moving
knife
1) The standard mounting position of the counter
knife and moving knife is the position at which
the center line of cutting portion of moving knife
is aligned with the center line of eye of counter
knife as illustrated in the figure.
2) If portion ⓐ of counter knife is larger than the
standard, three threads will be trimmed instead
of two threads in failure. If this phenomenon
occurs, threads will not be brought to the nor-
mal position after thread trimming. If potion ⓑ
is larger than the standard, the knives cannot
trim the threads. It is therefore necessary to
adjust the knives to the correct position.
3. Adjusting the thread trimming cam crank
1) Align the thread trimming cam cranks, right and
left with the flat position of thread trimming cam
crank shaft in the arrangement as shown in the
figure.
2) Slowly turning thread trimming cam crank shaft
❶ , align stopper lever ❷ with the flat portion
on thread trimming cam crank shaft ❶ .
– 13 –
Thread release
cable
Return spring