Adjustment Procedure
Results of Improper Adjustment
(Important) No lubrication is needed for the thread take-up
lever. (Maintenance-free mechanism)
When adjusting the thread take-up lever mechanism, the following
items shall be observed:
Replacement of the thread take-up lever
1. Remove the needle bar ❶ and the needle bar connector ❷.
2. Draw out the needle bar upper bushing ❸.
(Caution) Be careful not to hurt the needle bar upper bushing ❸
Needle bar upper bushing
❸
Remarks
Part No. 40172399
Position: 0.5mm hollow above
the
3. Loosen two needle bar crank setscrews ❺ of the main shaft
counterbalance ❹.
4. Loosen two thread take-up lever crank shaft setscrews ❼.
(The thread take-up lever support shaft ❻ is processed at.)
5. Loosen the thrust collar setscrew ❾ of the thread take-up lever
crank.
6. Pull out the crank shaft set toward you, except the thrust collar.
7. Remove the thread take-up lever (coupling) ❽.
Thread take-up level
❽
Part No.
Thread take-up lever stroke
Standard specication 40174341 110mm
Specication for heavy-
weight materials
40055604 108mm
8. Reassembly can be carried out in the reverse order for disas-
sembly. At that time, however, the items specied below shall be
strictly observed.
9. Insert the thread take-up lever unit to the position where it
comes in contact with the main shaft counterbalance ❹. Install
the crank shaft set in the order of the thread take-up lever
crank, the thrust collar, and the arm.
10. Fix the needle bar crank setscrew ❺.
(Cautions) The rst screw in the revolving direction shall be
made to coincide with the at section of the shaft.
11. Remove thrust rattles from the thread take-up lever crank shaft
❻ and x it being pinched by the thrust collar and the E ring.
(Make thrust adjustments so that there are no thrust rattles and
the thread take-up lever crank can slide smoothly.)
12. Drive the needle bar upper bushing ❸ to install the parts of
needle bar ❶ and needle bar connector ❷.
13. Turn the hand wheel by hand several turns in forward direction
and x the thread take-up lever crank shaft ❻ by means of the
thread take-up lever crank shaft setscrew ❼, keeping adequate
needle bar centering.
(Cautions)1. Improper centering of the needle bar ❶ causes
the thread take-up lever mechanism to be loaded
inadequately, thus greatly affecting the durability.
2. Coincidence is absolutely needed between the at
section of the thread take-up lever crank shaft ❻
and the screw.
3. After conrming that there is no thrust backlash,
assemble the take-up lever thrust collar.
◦ If this section is hurt, this will be a
cause of seizure.
◦ If there is thrust backlash, this will
be a cause of breakage of the
thread take-up lever.
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