Dry Hook; Cautions When A Dry Hook Is Used; Replacement Of The Dry Hook - JUKI DDL-8000A Engineer's Manual

9. Dry hook

WARNING :
Be sure to turn the power OFF before the following work in order to prevent personal injury due to
unintentional starting of the sewing machine.
Adjustment Procedure

(1) Cautions when a dry hook is used

For the dry hook (RP hook), lubrication is given to the hook race
with the use of a specific material.
In the case of continuous high-speed operation, it must be noted
that wear on the race is accelerated.
Lubricant shall not be applied to the race.
If any abrasion is perceived, change the old part with a new one.
(Caution) The RP hook (dry hook) tends to collect thread chips
and cloth dust, and this can be a case of malfunction
and defective stitches. For this reason, it should be
cleaned periodically.
Dry hook (RP hook)
Part No.
22890206 Standard type
22890305 Surface treatment type
22890404 Type with a needle guard
Bobbin case part No. for dry hook : 22896252

(2) Replacement of the dry hook

If a dry hook is installed according to the specifications of DDL-
8000A, the hook section can be treated as a device conforming to
the dry specifications and sewing can be carried out without lubrica-
tion.
* According to "3.-(6) Lubrication", set up the hook so that a very
small amount of oil is fed.
1. Take out the lubrication hook.
2. Remove the hook shaft filter asm ❶ that is mounted on the hook
shaft tip.
3. Install a lower shaft stop plug screw and O ring which is avail-
able separately.
Part No.
11079506
RO036080200
4. Adjust the amount of hook oil so that lubrication is maintained to
a degree wet with a small amount of hook oil.
(Cautions) 1. Do not drain oil from the oil tank.
2. Be careful not to allow the oil tank to be vacant.
This oil is used also to lubricate the lower shaft front metal.
Remarks
❶
Remarks
Lowe shaft stop plug screw
O Ring
– 133 –
Results of Improper Adjustment
○ Hook rattling occurs and there are
problems like heat generation and
defective stitches.
○ Contamination like black ink is
caused and this becomes a cause
of thread to be stained.
○ This is a cause of metal section
seizure.