Brother Industries BROTHER LK3-B220 User manual
INSTRUCTION
MANUAL
FOR
BROTHER
LK3-B220,
221
High Speed Bar Tack Machine
BROTHER
INDUSTRIES,
LTD.
NAGOYA,
JAPAN.
From the library of: Superior Sewing Machine & Supply LLC
CONTENTS
1. FEATURES ..
..
..
..
.....................
...
...............................
...
.
...
..
....................................................
2.
SPECIFICATIONS ............
..
......
...
..........................................................................................
~
3. OPERATION ............................................
...
...............................
....
........................................ 3
1.
Name
of
major
component ......................................................................
..
.
..
...............
..
... 3
2.
Selling up .............
..
....
..
.......
..
...........
..
....
..
...............
..
........
..
...........
..
..
..
......
..
...
..
...
..
...
..
.
..
... 11
3.
Oiling...............
..
.......................................................
..
...............
..
..
..
.................................. 7
4.
Safety
operation
............................................................................
..
.......................
..
......... 7
5.
Needle
and
thread
............................................................................................................. 8
6.
Winding bobbin ............
..
.......
..
........................................................
..
...
..
.............
..
........... 9
7.
Threading
bobbin
ca
se
....................................................................................................... 9
8.
Upper
threading
.................................................................................................................
10
9.
Thread
tension.............................................................................................
..
....................
11
10.
Adjusting
tack
width
··········
·
·····
··
·················
·
····
·
····
~
···
..:.:
························
··
····
··
·····
·
··············
12
11.
Adjusting
tack
length ........................................................................................................ 12
12.
Adjusting pressure of
work
clamp ..................................................................................... 12
13.
Cleaning shuttle .................................................................................................................
12
14
. Removing needle plate.......................................................................................................
12
15.
Installing needle plate........................................................................................................
12
16
. Replacing needle hole
plate
...............................................................................................
1:3
4.
ADJUSTMENT
........................................
..
............................................................................ 13
11.
Adjusting needle
bar
..
........................................................................................................ 13
2.
Adjusting feed mechanism .................................
..
...............................
....
....
..
..................... 14
3.
Adjusting
thr
e
ad
trimming mechanism.......................................
..
......................................
16
4.
Adjusting
thr
e
ad
nipper ............................
....
....
..
.............
..
..
........
..
.......
..
........................... IS
5.
Adjusting clutch and
brak
e......
..
........................................................................................
19
6.
Adjusting
wor
k clamp lifter ...................................................
..
.
..
....
..........
..
......................
21
7.
Adjusting
work
clamp on B221·1 and -2
............................................................................
22
8.
Needle cooler mechanism
(O
pti
on)
........
..
......
..
....
..
............
..
...............................................
23
5.
PARTS
LIST
for
LKJ-8220
...............................................................................................
24
From the library of: Superior Sewing Machine & Supply LLC
LK3-B220, 8221
High
Speed
Bar
Tacking Machine
The
~e
ma
c h
i
n
e
~
are h
ig
h
~
p ee
d
bar lacking mac
hi
nes c
ap
able to sew at
m
a~
imum
hi
~
!
h
~
p
eed
of
2.
000
~!
it
c
he
s
per minut
e.
The model
Ll\
:~
ll
22
0 b
~
u
itable
to do tacking jobs on overco
ats
. gent's pants. jeans.
m
·
e ra
l l
~
and
knilled
und
en
\
e
a
r
~
.
and the model LI\::.J-:
22
1
i~
suitable to do
tac
k
in
g
jo
b
~
on eyelet buttonhole e
nd
s,
belt
loops on
,l.(e
nl
\
<llld
la
d
ie
s
pa
n
t
~.
and jean: and Iabeii
in
.!.(
on \ arious clothe
s.
FEATURES
1.
This
is designed with cylindrical bed, link motion
thr
e
ad
tak
e-
up. and
shuttle
hook.
2.
On
thread
trimming mechanism,
BROTHER'
s own unique idea is adopted to be ensured perfect
thread
trimming
perf
ormances and
thread
tails
ar
e unified with this
thread
trimming mechanism. Also,
the
replacement of the
thread
trimming
knives
are
very easy.
3.
All
the mechanisms
are
designed to be
durable
even
at
max
imum high speed of
2,000
stitches per minute,
thus it is ensured the less noise and less vibration. Especially, the clutch mechanism is designed with speed
reduction method with
two
belts, and it ensures smooth
operation
when the machine
starts
and stops.
Thi
s
feature brings the noiseless ope
ration
and prevent the
thr
ead-off out of the needle.
Also, on the needle
bar
mechanism, it adopted with needle
bar
clamp
to ensun• noiseless operaticni
and
perfect
stitch
formations.
4.
All
the mechanisms
are
covered entirely
and
it is so-called
totally
enclosed type, thus it prevents
thread
jamming
and
oi
l stain.
5. It ensures wide
space
underne
ath
the work
clamp
with unique
de
signed
work
cla
mp
lifting me
ch
anism.
6. One of the
greatest
advantage
is
BROTHER's
own designed hook timing adjusting mechanism,
which is eliminated to adjust the space between
needle and hook point with wa
sher
dependent on
the
thickness
of needle.
This
adjustment is made
only by adjusting ring
to
get
proper
cle
aranc
e.
7.
The
belts
are
vertically put,
th
en it enables easy
setting
and dismantling
and
it
can
be
used
with
endless belts.
8. Bed
base
plays role of oil reservoir, thus it en·
sures no oil-leakage.
- 1 -
From the library of: Superior Sewing Machine & Supply LLC
-
SPECI
Fl
CATIONS
MODEL LK3-B220 LK3-B220 LK3-B220 I LK3-B220 LK3-B220 LK3-B220 LK3-B220 LK3-B220 LK3-B220
Sub-class I -1
-2
-3
--l
-5
-6 -7
-8 -9
Overcoats.
gent's
and
Knitted
gen
t'
s
Knitted
Denim
or
Denim
or
Overcoats,
Overcoats,
Application
Overalls, ladies'
Underwears
ladi
es
Unde
rwears
Corduroy
Co
rduroy
Overalls, Overalls,
Jeans,
etc.
pants
pan
ts
Jeans
Jeans
Jeans, etc.
Jeans,
etc.
;\
o.
of
stitch
I
42
28 28
21
21
42
28
42
28
Tack
length
I 6-
16
111m
:3.5
-
10111m
3.5-
8111111
3-
7111111
3-
7mm
7.5-
20
mm
6-
16111111
7.5-20
mm
6-16111m
I
Tack
\\'idth I 1-
3ml11
I 1-
3mm
1-
3111111
I 1-
3mm
1 -
3mm
1-
3mm
l -
3mm
1-
3mm
1-3ml11
:\Iax
i
mu111
sewing speed I 2
.0
00 spm 2,000
spm
2,000
spm
2,000
spm
I
2,0
00
spm
1,900
spm
1,900
spm
2,000
spm
2,000spm
:1\
ee
dle
bar
str
oke I
-!1.2
mm
41.2
mm
41.2111111
-!1.2
mm
41.2
mm
4L
2mm
4L2mm
41.2
mm
41.2
mm
Height of \\'o
rk
clamp
II
lOmm
10mm 10mm
10mm
lO
mm
lO
mm
10mm
lOmm
10mm
;\e
edle
movem
ent I N
MODEL LK3-B221 I LK3-B
22
1 LK3-B221 LK3-
B221
LK3-B221 LK3-B
22
1 LK
3-
B
22
1 LK3-B221
Sub-class I
-1
I -2
-3
--l
-5 -6
-7
-8
Application
IEyelet button-! Eyel
et
button-
Belt loop Labelling Labelling Labelling Labelli
ng
Belt loop
hole end hole end I
;\o.
of
stitch
28
I
21
21
-!2
32
28
21
28
Tack
length
3-
7mm
I 3-
7mm
5-
12
mm
20
-
50mm
14
-
35mm
18
-
45
mm
16
-
40111111
7.5-20mm
Ta
ck wi
dth
1-
3mm
I 1- 3
mm
0-
1.5111111
Omm
Omm
Omm
Omm
0-
1.
5mm
1\I
axim
um
sewing
sp
eed
II
2.
000
spm
2
.0
00
spm
2,00
0spm
2.
000spl11
2,
000
sp
m
2,
000sp
m 2
,000
sp111
2,000spm
l\
eed
bar
s
tr
oke
I
41.
2
ml11
I
-!1.2
mm
41.2
mm
41.2
111111
4L2mm
4L2mm
4
1.2111111
41.2111111
Height of wo
rk
clamp
lOmm
I
lOmm
lOmm
10111111
lOmm lOmm
10m111
lOmm
~
ee
dle
movement I
From the library of: Superior Sewing Machine & Supply LLC
OPERATION
1.
Name
of
major
components
(A) Model
LK3-B220
Thread take-up
Sub tension
assembly
Arm
cover
Belt
cover
lever----ffff1~~====~~==~~==~~==~.(
Cam
cover
Face
plate
Nipper
operating--
lever
111ain
tension
ISSembly
Presser
arm
Needle
bar
ITack
width
regulator
Emergency
stop
Bed base
motion
lever
(B) Model
LK3-B221-1
&
-2
(D) Model
LK3-B221-4
-
-7
F
UDTHER3
Bed
Work
clamp
lifter
(C)
Model
LK3-B221-3
&
-8
-3-
From the library of: Superior Sewing Machine & Supply LLC
2.
Setting
up
the
machine
*Location and measurement
of
table
top
for
LK3-B220
&
LK3-B221
*Location and measurement
of
table
top
for
LK3-B221-3
&
-8
A Holo for
ng
ht troodle
U H
ofo
for
lo
ft
troodle
C
Ho
lo
lor
motor
mounung bolt
D
Ha
lo for machine
bod boso
bo
lt
t:
Holo for
ho
nd rest
----------1200----------..j
*Putting
the
chains l
Work
clamp
lifter
l
Adjust
length
o
left
J'
oh•;"
Trea
~
Je_
'
.§
Clutch
actuatmg
, lever Clutch actuating
r-.~'""'-
"'
.__,.
· ·
rod
Left
treadle
Adjust
length
of
chain
Right
treadle
(Clutch
actuatin
g rod is included in accessories.)
*Putting
belts
Belt for h1gh
speed o
pe
r
at
1o
n
(l
on
ge
r belt)
- ·l -
wmder
From the library of: Superior Sewing Machine & Supply LLC
*Length
of
belts
In
·asc that you may usc
\\'
ith non-
BROTHER
mad
e table
and
stand, the
standard
length of
the
belts
ar
c
as follow
s:
-c
Longer belt
50 liz
Short
er be
lt
1,119mm
1,007
llllll
-c
Longer
belt
60H
z Sho
rter
belt
1,080
mm
992mm
In
case
that
you
ma
y use with non-
BROTHER
made
table and ·stand, please
determine
the
length of
belt
s
temporarily
sett
ing between mo
tor
pull
ey
and idle pulley, on condition
that
the
belt
is
not
stretched
,
and
cut
the
belts
being
30
- 40 mm s
hort
er
and
put
the both ends together
as
descr
ibed hereunder.
(NOTE)
Be careful to
get
prop
er tension
of
the belts. In
ca
se
of loose
tension
, it
cannot
run
at
prop
er
speed
and
tight
tension, it
caus
es
too heavy
torqu
e.
*MOTOR
Single
phase
250W
Three
phase
250W
*Joining
belts
~~§:
/Heated~
Belt Belt
4 pole
4 pole
*MOTOR
PULLEY
2,000 spm
50
Hz
130mm
60Hz
llOmm
Sharp
knife
~
t=-=-I;
- -
6--
Remove
1,900 spm 1,700 s
pm
1,500
spm
1,300
spm
120
trim
108mm
96mm
84mm
102mm
92mm
82mm
72mm
Base
for
belt
joining
The
belts
contained
with
this
machin
e
head
are
made
of
polyule
thane
rubb
er
of
Smm¢,
which
do
es
not
cause
any
slippage on
machine's
running,
and
with
the
he
at
adhesion it
ensur
es
durability
without
any
anxiety
of
breakage
on
the
joining points
during
the
operation:
Please
take
the
following
steps
to
adhere
the
belts.
(1) Cut
the
belts 30-
40
mm
shorter
than
the
length
that
it
se
ts te
mpor
arily be
tw
een the pull
ey
s
of
motor
and
machine
head
.
(2)
Melt
the
both
ends
of
the
belts w
ith
heat
such
as
li
g
ht
er flame, h
ea
ted
iron
plat
e
and
th
e
li
ke.
(3)
Put
together
both ends on
ba
se
for
belt
joining
th
en
pr
essing each end
and
le
av
e it
about
3
minut
es
without
remov
ing
the
contact
using
base
for
belt
joining contained in access
or
ies.
(4)
Remove
the
surplu
s with s
harp
knif
e as per
illustration
.
- 5 -
From the library of: Superior Sewing Machine & Supply LLC
*Setting
spool stand
*Checking
speed reduction
Photo 1
Photo 2
Photo 3
o
Without
running
th
e motor,
wh
en clutch
is
ra
ised, the
belt guide is pos
it
ioned at slow speed
pulley
and
idle
pulley as per Photo
1.
o
With
turn
ing
th
e pulle
y,
when clutch
tr
ipp
ing
cam
lever
is disengaged out of s
top
ca
m, the belt g
uide
lever is
positioned
at
slow speed pulley and
idlt>
pulley
as
per
Photo
2.
o
At
a few sti
tch
es bef
or
e
th
e machine stops, when
clutch
tr
ipping
cam
lever is
at
th
e stop cam,
th
e
belt
guide
le
ver
is positioned
at
slow speed pulley a
nd
idle pulley
as
per
Photo
1.
o
At
the stop position, the belt guide lever is positioned
at
idle pu
ll
ey and bobbin winder pulley as per
Photo
3.
6
From the library of: Superior Sewing Machine & Supply LLC
3.
Oiling
Supply one or two drops of quality sewing machine oil inlo oil holes with
arrow
indicated before using
the machin
e.
10
drops
1
10drops
(L-
!14
I
5
drop
s
I
'
I
' I
4.
Safety
operation
Ri
ght
treadle
Left
treadl
e
- 7 -
o When the switch is "ON",
motor
s
tarts
to run and the
id
l pu
ll
ey
s
tart
s to run.
l Release the right tr a
dl
e when
the
ma
chine is in op
era
tion.
(Machine
st
ops automatically)
r;
When the left trea
dl
e is d
e-
pressed, it works the th
rea
d
trimming and thread nipper
mechanisms
an
d
li
fts work clamp.
From the library of: Superior Sewing Machine & Supply LLC
oEven
it
the left treadle
is
accidentally
depressed while the machine
is
in
opera·
tion. \\'ork clamp
stays
clown
.
5.
Needle
and
thread
*Selection
of
needle and thread
Needle size
Thread
size Application
# 9 #
100
-
#80
Tricot, fine knitted under
wear
#11 #
80-
#60
II II
#
14
#
60-
#50
Men's and Ladies' wears
#
16
#
50-
#40
Work clothes. overalls, overcoats
#
18
#
40
-
#30
II
II II
#
19
#
30
-
#20
II II II
#21 #
:W
- # 8
Thick
overcoats,
Jean
s
*Installing
the
needle
Loosen
this
s
crew
.,...;w~......:~
II
Insert
needle all
the
way
up
into
need4e
hole
in
the
needle bar,
with
its
long
_
___,.,,,
groove
facing
toward
you
and fasten needle
tightiY--t
J--->...\.,
,.......
.
-J
with
the
screw.
To
stop the machine during the opera-
tion. depress the emergency stop lever
before completing sewing cycle.
position)
o When the work
clamp
is raised up, the
machine will not
start
even if the right
treadle
is
accidentally depressed.
Left-twisted
thread
~
The
twist
is
strengthened
in case
of
left-wisted
thread.
• Use a left-twisted
thr
ead for
upper thread.
From the library of: Superior Sewing Machine & Supply LLC
*List
of
needle
to
be recommended
L
K3
-B2
20
-1 LQ x s #
16
LK3-B
22
0-2 LQ x s #
16
LK3-B
22
0-3 LQ x s
#11
LK3-B
22
0-4 LQ x s #
16
LK3-B220-5 LQ x s
#11
LK3-B220-6
DP
X
17
;!:!:
21
LK3-B220-7
DP
17
#21
LK3-B220-8 LQ x 5 #
16
LK3-B220-9 LQ x 5 #
16
6.
Winding
bobbin
1)
Put bobbin onto bobbin winder spindle.
2)
Wind a few turns of thread on bobbin.
3)
Press bobbin presser as for as it goes.
(Thread correctely wound on bobbin.}
LK3-
B221
-l DB X1
#1
4
LK3-
B221
-2 DBx 1 #
14
LK3-
B221
<3 LQ x s #
16
LK3-
B221
·4 DB x 1
#11
LK3-B221
-5
DB x 1
#11
LK3-B221-6 DB x l
#11
LK3-B221-7 DB x 1
#11
LK3-B221-8 LQ x 5 #
16
(
If
thread
is
unevenly wound on bobbin.......)
~l:e
Raise the position of
tension discs. Lower the position of
tension discs.
*The
position of tension d
is
cs can be adjusted by positioning up
or
down the tension colla
r.
7. Threading
the
bobbin case
.....
Tension
spr
i
ng-~"'--10:
1.
Put
bobbin in bobb
in
~
-
!'
ass the thread
Slot
case. through slot and
under the tensi
on
spring
- 9 -
3. Pull the th
rea
d out 4. Lead the thread
of delivery eye under through ho
le
in po·
the tension spring. sition f
in
ger and
leave about
:k
m
of the thread out.
From the library of: Superior Sewing Machine & Supply LLC
8.
Upper
threading
S.
II
old
latch.
ins
ert
bobbin
case
onto
pin
at
the
centre
of
shuttle,
and
release
latch
when
bobbin
case
properly
placed
.
Le
ave
about
4 em of
the
thread
hanging
on.
-
10
-
From the library of: Superior Sewing Machine & Supply LLC
9.
Thread
tensions
*Lower
thread tension
\ Adjust the lower
thread
tension so
that
you will feel a s
li
ght resistance
in
pulling the
thread
from the bobbin
ca
se.
(15
-
30
gram
s for
#50
cotton thread)
Me
as
ur
e the tension
by
the tension
ga
uge as per the illustration.
After adjusting the lower
thr
ead tension, adjust the upper thread tension by
means of the main tension.
*Upper
thread tension
*Main tension
This
adjustment is affected the sewing condition, therefore, adjust the tension to be following
li
st
dependent on sub-class,
thread
and
materials
.
Tension
LK3-B220-1
-
-5,
-8
-
-9,
8221-1 -
-3,
-8
..........
70
- 80 gr.
LK3-
B220-6
- -7...............
...........................
150
-
200
gr.
LK3-B221-4
- -7.............
..
.
..........................
50-
60
gr.
Thread
Dacron
#50
Cotton
#50
Dacron
#80
When the thread is trimmed
after
the
main
tension is re
le
ased
at
the final stitch, enough length
of
the upper
thread
should be left put of the needle eye.
*Sub
tension
Sub tension plays a role to prevent the upper
thr
ead from loosening when the
thr
ead is trimmed.
Adjust the sub tension
so
that
the upper
thr
e
ad
will be fairly taut between the needle and
th
e
material
when the machine stops.
(40
-
50
gr
. for
B220-6
-
-7;
5-
25
gr. for all
oth
er sub-classes)
*Thread
take
up spring stroke and
its
tension
Stroke Thread
>-.,.
'\~~r.~·
Th
is adjus
tm
ent is also affected much on the sewing condition.
Thread--{]
..
guide ; :
:)
~Ten©n
~
T .
eusron
gauge
S
tro
ke
LK
3-
B220
-1-
-5
,
-8
-
-9
}
LK
3
-B221
-1-
-3,
-8
························3 mm
LK
3-
B220
-6- -7........
..
.......
..
............... 6- 8 mm
LK
3-
B22
1-4- -7
..
.............................12.5- 1
3.
5 mm
-
11
-
Tension
15- 20
gr
.
2
20
-
30
0 gr.
15-
22
0 gr.
From the library of: Superior Sewing Machine & Supply LLC
10.
Adjusting
tack
width
g
Adjust by loosening adjusting screw and
moving hinge
bluci<
in
vertical direction.
11.
Adjusting
tack
length
Adjust by loosening thumb screw and mov
in
g
it
along with the slot of the
tack
length
regulator.
1
2.
Adjusting
pressure
of
work
clamp
13.
Cleaning
shuttle
1.
Remove shuttle
race
with
Adjust the work
clamp
so
that
it
exerts
no more pressure
than nece
f.
sary
to prevent the
material
from slipping.
2. Remove shuttle. *After cleaning, put a
drop
of
bobbin case. oil ins
id
e of shuttle race.
14.
Removing
needle
plate
15.
Installing
needle
plate
R move four flat he
ad
s
cr
ews and
th
en nee
dl
e
Match
markin
g in assembling.
plate.
- 12 -
From the library of: Superior Sewing Machine & Supply LLC
Thread
presser
__
Upper
thread
knife
Lower
thread
knife
~
Set
screw
Thread
Presser
1
6.
Replacing needle
hole
plate
Upper
thread
knife
Lower
thread
knife
*The
needle hole plate can be removed by loosening two
set screws and pushing it upward.
The
needle hole must
be
very smooth.
* Replace the needle hole plate
if
the needle hole IS con-
siderably damaged.
*When
putting a new needle hole plate
in
replacement,
make sure the groove on its underside is
in
line with the
groove
in
the needle plate.
*Needle
hole plates
ar
e available
in
standard size (1.6mm
in
needle hole diameter); and special size
(2.2mm
in
needle hole diamete
r)
for thick
mat
erials, and another special size (4.0mm
in
needle hole
diameter) for ultra heavy materials.
ADJUSTMENTS
1.
Adjusting
needle bar
The
proper needle
bar
rise and needle
bar
heig
ht
ar
e necess
ar
y for the nee
dl
e in its upward travel from
the lowest point to form the correct loop of the upper thread a
nd
for the shuttle point to prope
rl
y hook
the loop.
(1) Needle bar rise
When the needle bar comes up from downmost to below-
mentioned measurement, the shuttle point must be in line
\\"
ith the centre axis of the needle. Adjustment can be
made by loosen
in
g two shut
tl
e driver set screws and
turning the shuttle driver as required and fasten the s
il
ver
screw matching with the
gr
oo
ve
of low
er
shaft a
nd
then
black screw.
- 13 -
From the library of: Superior Sewing Machine & Supply LLC
Shuttle driver
(2)
Needle bar height
Shuttle Needle
p~~
ll
r-1
'l1T2
~·
Make
sure
Lhal
the shullle driver is
in
close
contact
with lhe
rear
side
of shuttle point.
LK3-
B220
-l - ·5, -H- -9 } .........
LK3-
B221
-l - -3, -8 2.8
111111
±
0.2
111111
LK3
-
B220
·6- -7............
..........
2.5
mm _ O.lmm
LK3-
B221
-4- -7
.....................
2.5
mm 0.2
m111
(NOTE) LK3-
B220
-6 & -7 for Denim. only one screw is sel.
When
the
shuttle point is
in
line with the
centre
axis
of the needle, the
correct
distance between the lop of the needle eye and the shuttle point
is
as
follows.
If
adjustment
is
required, loosen the needle
bar
connecting stud
scr
ew
and
raise
or
lower the needle bar.
LK3-
8220-1 - -
5.
-8-
-9
) .
J ..
.......
2.0
111111
± 0.
3mm
LK:~-
B221-l -
-3,
-H
LK3-B220-6-
-7
.....................
1.2mm ± 0.2mm
LK3-B221 -4- -7 ......
..........
...
..
2.0mm ± 0.
3mm
(3)
Clearance
between
the
needle and
the
shuttle point
Needle1C
- o.
os....
.
~Shuttle
pomt
2.
Adjusting
feed
mechanism
Thl'
corr
ect
clearan
ce be·
tween the centre of needle
bein
).!
met with
shuttle
po
int is
0.0
:
~
-
0.0Hmm
.
To
adjust the
clearance,
loosen the s
huttle
hook
s
et
s
cr
ew
an
d
rot
ate
the
adjusting screw
and
fasten
the s
et
s
cr
ew tightly
after
completion.
Bar
tacks
will be made as the power is
tran
s
mitt
ed to t
ack
len
gt
h
an
d tack width mechanisms
th
rough
the
outer
and inner
groove
s of the feed ca
m.
The
tack
design
stays
within the re
ctan
gul
ar
opening in the work clamp and even when the swing ts
expanded by feed adjustment, its centre must always be at the
sa
me point.
(1)
Needle and feed cam
Feeding begins as soon as the needle rises out of the material and ends before needle comes down into
the material.
If
adjustm
ent
is required, loosen the wo
rm
wheel shaft nut and the
hexag
onal bolt and
turn
the feed
cam
by degrees.
Turnin
g the feed
cam
in its
rotat
ing direction, it advances the feed Liming
an
d vice v
er
sa.
(NOTE) LK3-B220-6 & -7 for Denim. the Liming of feed cam should he advanced a h
it
earli
er
.
- u -
From the library of: Superior Sewing Machine & Supply LLC
(2)
Adjusting
tack
width
motion
(Except
LK3-B221-4
- -
7)
Adjusti
nM
tack width and lack length motions require very delicate and precise cautions.
Make
ad-
justments
fi
rs
tl
y
on
the tack width motion and then tack length motion with
great
care. Once the
correct
adjustment was made, no further adjustment
is
necessary
unl
ess absolutely required.
First of a
ll
, adjust to gel the correct position between work
cl
amp
and feed plate
by
loosening
clamp
frame s
el
bolt.
(3)
Adjusting
tack
length
motion
I) Let the first needle come down
into the needle hole.
2) Loosen the adjusting screw and
raise the hinge block until the
hinge
bl
o
ck
is
in
le
v
el
with the
tack
width regulator lever shaft,
and tighten the adjusting
scre
w
3) Loosen the feed bracket, fastening
screw.
mo
ve the press
er
arm
and
sel the
po
sition of bracket so
that
the needle hole
wi
ll
come
exa
ctly at the centre of work
clamp
,
then tighten the
fa
stening s
cr
e
w.
4)
Loosen the
tack
width lever fa:tening s
cr
ew and lower the
hinge
bl
ock all the way down, then
ti
ghten the fastening s
cre
w.
Again, move the presser arm and set the pres
se
r
ar
m so
tha
t
the needle hole will come exactly at the
centr
e of work clamp,
then tighten the fastening screw.
1)
Raise the clutch and
turn
the
dr
iv
ing pulley by hand until
tpe
nee
dl
e comes down into the needle hole
wi
th tack length
regulator
in
the marked
po
sition of the rim of the feed cam.
2)
Loosen the feed
brack
et fastening screw, when the tack length
regu
la
tor
rod brings to its fullest ext nt in the elongated hole
of the ta
ck
length regulator lever, set the po
si
tion of
bracket
not so as to move the
work
clamp.
:i)
Loosen ba
ll
stud and s
et
the po ition of press
er
a
rm
so
that
the ce
ntr
e of
work
clamp will come to the needle hole, then
tighten the ball stud.
- 1
5-
From the library of: Superior Sewing Machine & Supply LLC
(4)
Adjusting
motions
on
LK3-B221-4
-
-7
I)
Adju~ting
lack length motion
(i) At the
~top,
mo
ve
pre~~er
plate for guide
ba
~
e
back and forth
~o
that
the needle hole plate may
be positioned
at
the
centre
of feed plate window.
(ii)
Make
the tack length
at
maximum and
make
~ur
e
that
the above position is kept during one
cycle.
In
case of adjustment. readjust the position of feed plate window.
2)
Adjusting dial of labelling
The
dial plays a role to determine the position of label.
When you set the material by work
damp,
put the label
unci
·r
·
neath the dial to its
exte
nt to fix the
po
sition, then you can get
the pre-determined,
constant
measurement on the materials.
This
adjustment
is
made
by
moving the dial back and forth.
3.
Adjusting
thread
trimming
mechaism
Fastening
screw
Labels'~
The
upper thread knife, lower thread knife and thread presser
are
mounted to the pinion
~tud
brack
et
and
are
oparated by the power
transmitted
from the knife
cam
.
1)
As the needle rises out of the needle hole
after
the first stitch, the
thread
presser catches the upper
thread
to prevent the thread from slipping out.
2)
The
thread presser releases the
thread
just before the fifth stitch is formed.
3)
As soon as the upper
thread
is
pulled up by the
thread
take
-up lever, the lower thread knife
catches
the lower threarl. At this moment, the tip of the upper
thread
knife is just
in
front of the needle hole.
4)
The
upper thread knife enters the upper thread loop while the
shuttle
point comes to its downmosl
po~ition
after
catching the loop in the process of forming the final stitch.
5)
The
machine stops. When the left treadle is depressed, the connecting rod adjuster disengag
es
fr
om
the tip of the knife
bar
and
the connecting rod spring pulls the knives to trim both thread
s.
*
In
adjusting the knives, firstly remove the needle plate and
make
sure the knives
ar
e installed
correctly.
Th
e
n.
mak
e adjustments
in
the following steps.
(1)
Thread
trimming
lever
roller and
lower
thread knife
At
the
thr
ead trimming lever roller is just above
the recess portion of the kni
fe
cam,
that
is the
second stitch, and
at
the stop po
si
tion of
thr
ea
d
trimming knives, the point of low
er
t
hread
knife
is positioned at the red
mark
of the nee
dl
e plat
e.
-
16
-
Thi
s adju
st
ment is made by loosening the
rack
a
nd
mo
vi
ng it back and
fo
rth.
From the library of: Superior Sewing Machine & Supply LLC
(2) Timing
of
knife cam
Lo
oHen
the
fa
stening screw for knife
cam
(A)
and adjust
the
timing so that the needle may not touch the thread trimming
knives and the upper thread loop
may
not touch the knives.
Adjust the thread trimming
cam
(B)
by loosening fastening
screw
so
that
the upper thread knife may hook the upper
thread
loop
during hook point
tr
av
elling
downward
with upper thread loop
at
the final stitch.
(3)
Lower
thread knife and thread trimming lever
(4)
Adjusting thread
trimming
stopper
screw
~hole
~pper
thread knife
At the stop position,·
loosen two screws
and
adjust the thread trim-
ming adjusting screw
so
that
the point of
lower
thread
knife will be po·
sitioned
at
the red
mark
on the needle plate.
When work
clamp
is lifted up, adjust by stopper
screw
so
that
thread
trimming lever roller
may
be
apart
about
0.
3mm
from the bottom of knife
cam
.
At
this moment, the needle hole is positioned
at
the
rear
of upper thread knife.
- 17 -
From the library of: Superior Sewing Machine & Supply LLC
(5)
Tension
of
connecting rod spring
If
the connecting rod spring has too weak tension, the knives
often fail to trim the threads and
in
.some
extreme
cases, collide
with the needle causing to
break
. If.
on
the other hand, the spring
has too strong tension
extra
power will be needed to
drive
the
knives. thus the machine does not work smoothly.
To
adjust the
spring
tension, loosen the spring hook set screw and move the
spring hook left
or
right.
4.
Adjusting
the
thread
nipper
As the needle begins to rise for the final stitch, the upper thread knife enters the upper thread loop.
And the main tension
is
released
to
allow sufficient length of the thread for the knife.
When the left treadle
is
depressed, it
works
the thread nipper mechanism and
at
the first stitch, the
needle
bar
thread nipper
is
lightly tightened to prevent the thread from slipping and being jammed.
Before the needle comes down for the second stitch, the thread nipper
is
released and the main tension
is
tightened. Make adjustments, if necessary, in the following manner.
(1)
At the stop position, adjust the roller position
so that its
centre
will be matched with the red
marking.
(2)
Adjusting timing
of
the
thread nipper
Adjusting
screw
----Ill
-.....~at-----Thread
nipper
adjusting
lever
pawl
Timing
line
n;pp"
•haft
f
\l!..--f"
--
7>--+~
0 Guide
shaft
nipper
shaft
lever
-
18
-
At the position of the
roller being over the re·
cess posit ion of the
cam,
the end of guide
shaft
must be positioned
at
the
upper line of the cam.
In case of adjustment,
loosen the fastening
screw
and
rotate
the
thread
nipper shaft.
From the library of: Superior Sewing Machine & Supply LLC
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