– 17 –
Adjustment Procedure
Results of Improper Adjustment
1. Remove the throat plate.
2. Set the stitch dial to [0] on the scale.
3. Loosen the clamping screw
of the hook driving shaft set collar.
4. Slightly loosen the set screws
and
of the hook driving shaft
saddle.
To loosen the hook shaft base mounting screw
for the LU-2220N-
7, loosen the setscrew
and take out the thread trimmer air cylin-
der mounting plate
.
To move the hook shaft base of the LU-2220N-7 to the right or left,
remove three setscrews
(hexagon socket head cap screws) and
take out the thread trimmer air cylinder together with the thread
trimmer air cylinder mounting plate
. Since then, loosen the hook
shaft base mounting screws
and
, and move the hook shaft
base to the right or left.
5. In the state that the needle holder is not effective, adjust the gap to
0 to 0.05mm between the needle and the hook blade point.
6. Turn the eccentric pin
of the hook driving shaft saddle with a
screwdriver to move the hook driving shaft saddle in the opposite
direction of the operator ( ) until it will go no further.
7. Fix the hook driving shaft saddle, holding it in the state describing in
step 6, by fastening the set screws
and
in the hook driving
shaft saddle in the written order.
8. Turn the needle holder effectiveness adjusting screw
and adjust
the effectiveness value to 0.15 to 0.2mm until the gap between the
needle and the hook blade point is adjusted to 0.05 ~ 0.1mm.
9. At this time, confirm that the clearances
A
,
B
,
C
and
D
in the
hook driving shaft coupling are respectively adjusted to 2.5
±
0.3
mm.
If not, adjust the clearances properly.
10.Confirm that the needle-to-hook timing is correct. If the timing is
correct, fasten the clamping screw
of the hook driving shaft set
collar. if not, refer to [(4)-3 Timing between the Needle and the Hook].
When the gap between the needle and the hook blade point has
been adjusted for the LU-2220N-7 and timing for the needle and
the hook has been checked and adjusted, install the removed thread
trimmer air cylinder mounting plate on the hook shaft base.
After the installation, it is necessary to readjust the thread trimmer
system.
o If the clearance between the
needle and the blade point of the
hook is too large:
Stitch skipping or improper thread-
ing may result.
o If the clearance between the
needle and the blade point of the
hook is too small:
The needle may interfere with the
blade point of the hook. As a re-
sult, the blade point of the hook
may be damaged and thread
breakage may be caused.
