– 11 –
2) Adjustment of the right and left feed dog positions, height, and
gradient
o Right and left feed dog positions
1. In order to make the right and left clearances be uniformly balanced
between the hole of the throat plate
and the feed dog
, loosen the
feed base arm setscrew
to move the feed base arm
in the axial
direction. After adjustments, tighten the setscrew
.
2. If the above-mentioned adjustments are insufficient, loosen the set-
screw
of the feed dog
and adjust the feed dog
and the feed
bar until they become parallel to each other. Since then, tighten the
setscrew
and adjust the horizontal positioning (adjustments of 1.
above) of the feed dog
again.
(Caution) When the gauge is replaced, make right/left adjustments
of the feed dog
.
o Feed dog height
1. Minimize the feed amount by rotating the feed adjusting dial.
2. Turn the hand wheel so that the feed dog
is positioned to secure its
maximum protrusion from the throat plate
.
3. Loosen the setscrew
and rotate the vertical feed link shaft
to
adjust the feed dog
to 1
±
0.1mm from the upper face of the throat
plate
. After adjustments, tighten the setscrew
.
(Caution) 1. After adjustments, the needle location may be changed
in relation to the hole of the feed dog
.
o Feed dog gradient
1. Remove the cap
of the bed side face and loosen the feed bar shaft
setscrew
. Turn the roulette section
to adjust the gradient.
Standard adjustment
o LH-4128, LH-4128-7, LH-4168-7
Position where the engraved marking dot
C
of the feed base arm
coincides with the engraved marking dot
B
of the feed base arm shaft
. (Engraved marking dot
A
is applicable to the LH-3500.)
o LH-4188-7
Engraved marker line horizontal
When the feed dog is positioned too
high:
o The feed dog
will come in
contact with the throat plate
.
o The stitch length will be larger
than the value indicated by the
scale on the stitch dial.
o It can be a cause of thread
trimming deficiency.
When the feed dog is positioned too
low:
o The pitches of stitches become
smaller than the graduations of
the feed adjusting dial.
o The moving knife will come in
contact with the feed dog
at
the time of thread trimming.
This can be a cause of trimmer
malfunction.
Adjustment Procedure
Results of Improper Adjustment
Содержание LH-4128-7
Страница 11: ... 7 MEMO ...
Страница 30: ... 26 1 2 3 4 4 Oil in the feed box Standard Adjustment 5 Replacement of the hook shaft oil wick ...
Страница 34: ... 30 2 Center link section Standard Adjustment ...
Страница 46: ... 42 3 Adjusting the thread presser spring A Standard Adjustment ...
Страница 50: ... 46 6 Adjustment of thread tension release Standard Adjustment Clearance 0 ...
Страница 65: ... 61 MEMO ...
Страница 68: ... 64 10 Installation removal of the needle bar rocking base B A ...
Страница 86: ... 82 MEMO ...
Страница 88: ...MEMO ...
