Brother DB2-8773, DB2-8774, DB2-87740 Service Manual
SERVICE
FOR
082-8773
082-8774
082-87740
MANUAL
SINGLE NEEDLE
BOTTOM FEED
ADJUSTABLE
LOCK
STITCH
TOP AND
MACHINE
I
NAMES
I
SPECIFICATIONS
I
MECHANICAL
OF
MAIN
rn
Upper shaft and needle bar mechanism 0 0 0
[2}
Lower shaft and rotary
IJJ
Upper feed mechanism . 0 0
1!1
~
Feed
Feed
mechanism
adjusting mechanism and quick reverse mechanism 0 0 0 0 0 0 0 0 0 8
[§]Upper feed mechanism and shirring mechanism (subclass -006) 0 0 0 0 9
[l]Threadtrimmer
liD
Tension release
~Thread
1m
Automatic
lllJ
Lubrication
CONTENTS
PARTS
I·
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
DESCRIPTIONS
wiper
(subclasses
presser bar
me~han
I·.........................................
0.
0 0 0 0
0.
0 0 0 0 0 0 0 0 0 0 0 0 0 0 5
..
00000
...
0
••
0
••
ism
hook
oooooooooooo
lifter
mechanism . o o
0. 0 0.
0 0
•• 0 0. 0 0. 0. 0.
0 • 0 0 0 • 0 0 • 0 0
0 • 0 • 0 • 0 0
••
0 0 • 0 0 • 0 • 0 • 0 0 • 0 0 0 0 0 0 • 0 0 • 0 0 0 0 0 7
••• o •• o .o.o.o.ooooooooooooooooo
••
0 0 0 • 0 0 0 0 0 0 • 0 • 0 0 • 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0
-400, -900) 0 0 • 0 0 0
••
0 0 o o 0 0 0 0 0 • 0 0 • 0 o
0 0 0 0 0
0. 0 0.
0.
0 0
0.
0 0 0 0 0 0 0 • 0 0 0 0 0
mechanism (subclass -900) 0
. 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0 0 0 0 • 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
••
0 0 5
0 0 0 0 0
0.
0 6
0.
0 0
0.
0 0 0 0 0 0 0 0 0 14
5
10
13
13
15
I
DISASSEMBLY
[I]Machinecovers
lZJ
Presser
[ID
Upper feed mechanism . 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 • 0 • 0 0 • 0 0
1!1
Rotary
f.SlThreadtrimmer
[§]
Feed
mechanism 0 • 0 0 0 0 0 0 0 0 0 0 • 0 0
[1]
Needle bar mechanism .
I
ASSEMBLY
[]
lZJ
[ID
1!1
~
rnJ
[1]
I.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Needle bar mechanism 0 • 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0
Feed
mechanism 0 0 0 0 • 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Thread
Rotary
Presser
Upper feed mechanism 0 0
Machine covers 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
'ADJUSTMENT ,
,.
. . . . . . . . . . . . . . . . . . . . . . . .
·o···ooooooooo··o•oooooo•o•o•ooo·ooooooooooooooo
foot
mechanism 0 • 0 • 0 0 • 0 0 • 0 • 0
hook
trimmer
hook
foot
mechanism 0 • 0 0 0 0 0 0 0 • 0 • 0 0 • 0 0 0 • 0 • 0 0 • 0 0 • 0 0 0 • 0 0 0 0 0 0 0 0 0
...
ooooooooooooooooooooooooooooo•ooooooooooooooo
0.
0 0 0 0 0 0 0 0
. 0 0 0 0 • 0 0 • 0 0 0 0
mechanism . 0 0 0 0 • 0 0 0 0 0 0 • 0 0 • 0 0 0 • 0 0 • 0 0 • 0 0 0 0 0 0 0 0 0 • 0 0 0 •
mechanism 0 0 • 0 0 • 0 0
0.
0 0 0 0
..
. . . . . . . . . . . . . . .
••
0 • 0 • 0 • 0 0 • 0 0 • 0 0 0 0 0 0 • 0 0 0 • 0 0
••••
0 0 • 0 0 0 • 0
0. 0 0.
·0
0 0 0 0 0 0 • 0 0 • 0 • 0 • 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0 0 0
••
0 0 • 0 0 • 0 0 0 • 0 0 • 0 0 • 0 0 0 0 0 0 • 0 0
0.
0.
••
0.
0. 0 0.
0 0
0 0 • 0 • 0 0 • 0 0 • 0 0
........................................................
..
. .
.. . ..
••
0 0 0 0 0 0 0 0 0 0 0 0
••••
0 0 0 0 0 0 0 0 0 0 0 0 0 0 • 0
0. 0 •• 0 •••••
••
0 0 • 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 • •
0. 0 0.
0 0 0 0 0 0
0 0 0 0 0 0 0 0 0 0 0 0
0.
••
0 • 0 0
0.
0 0 0 0 0 0 0
••
0 • 0 • 0 0 0 0
. . . . . 17
17
18
18
19
19
20
21
22
22
~
23
25
27
••
0 0 0
28
29
30
31
[I] Adjusting
[l]
Adjusting
[ID
Adjusting
1!1
Zeroing feed regulator and adjusting reverse lever
~Adjusting
rnJ
Adjusting
I1J
Adjusting presser
the
the
the
the
the
timing
timing
fofward
timing
timing
foot
between needle and rotary
between needle and feed
and backward stitch lengths 0 0 0 0 0 0
of
upper
of
the
0 0 0 • 0 0 • 0 0 0 0 • 0 0 0 0 0 0 0 • 0 0 0 0 0 • 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 37
feed horizontal movement 0 0 0
upper
feed vertical movement 0 0 0 0 0 0 0 0 0 36
hook
0. 0 0.
0.
0 0 0 o o 0 o o o o o 0
0 0 0 0 0
0. 0 0.
0. 0 0.
0. 0 0.
0 0 0
0 0 0 0
0 0
0.
0.
0 0 0 0 34
0.
0 0 0 0
31
32
33
35
liD
Adjusting
liD
Adjusting tension release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
IDl
Adjusting
lll1
Adjusting synchronizer {082-8774) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
1121
Adjusting
1131
Adjusting
1m
Checking feed mechanism
ll51
Adjusting sensor position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
Ill
Adjusting
sensor (877
I
REPLACEMENTS
li1
Replacing Solenoids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
l1l
Replacing tension release
~
Replacing
~Replacing
[SJ
Replacing Synchronizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
thread
thread
thread
potentio-meter
the
40) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
I.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
bobbin
photo-cell and
trimmer
tension . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
wiper
indication
tension spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
(87740) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
weight
of
the
wire
reflector
(87740) . . . . . . . . . . . . . . . . . . . . . . . .
distance
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
between
{87740) . . . . . . . . . . . . . . . . . . . . . . .
needle
hole
and
39
41
44
50
50
51
53
I OPTIONAL
li1
l2l
EQUIPMENT!................................................
Thread
Presser
wiper
foot
I TROUBLESHOOTING
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
lifting
GUIDE
solenoid set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
I.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
54
55
59
INAMESOF
MAI
N PARTS I
[082-8773
0 Needle
@ Presser
-003]
bar
regulating
[082-8774]
@ Thread retainer
screw 0 Tension
nut
[082-8773-006]
@Machine
@ Reverse lever
[082-87740]
pulley
0 Needle bar @ Pre-tension
Co
ntr
ol panel {87740)
brother
@Presser
~
EXE~A·
regulating
~-m
r 3
~
1om
o@
screw 0
~nrg
o~ ul!l)il~
Tens
ion nu t
~~
oooo
~
Fo4l
fo
4 0 l
~~ ~·lruM
W"~l"'
-1-
SPICII>=
1 H +
+0.5
I
H -
@Machine
@ Reverse lever
A
B
c 0
IDDDD
r3Jrill§~
'r\~:
tc
~
~~~
pulley
COftRECTlON
I +
I:::
~
STTTQtES
I
+!-!..
Base
[DB2-B774]
[DB2-B7740]
Motor
Thread w iper
Power swi
Quick rever
Compensation
tch
se
-
2-
se
w
.
1ng
Thread t
Automatic
rimmer
presser bar I i
fter
SPECIFICATIONS
I
..,
BROTHER
INDUSTRIES,
LTD.
082-8773-poq
MADE
IN
JAPAN
""
w hen
more,
mm
3
Use
m m when a pucker type gauge (assembly A)
or pucker-control gauge (assembly
on model 082-8772-006.
The
the
upper feed
or
500
or
spm.
When
more,
the
lower
use
a sewing speed
a maximum feed amount
specifications
BROTHER
of
082-8774
INDUSTRIES,
082-8774-···
MADE
IN
JAPAN
==------.!
Thread
trimmer
Thread
wiper
Quick back
Automatic
Control
presser
bar
lifter
Ply sensor
panel
-30 -40
0 0 0
~
0
/ /
E20, E40,
amount
feed
with
LTD.
L--..J
I
0
0 0
Option
E100
.J
is
6 mm
amount
less
of
less
C)
is
than
than
1s
used
or
automatic thread trimmer are shown below.
.J
-90
0
0
(option)
ODD
Medium material
AssemblyS
Maximum Stitch length
Maximum upper feed
Presser
foot
height
4
6
Use
Sewing speed
Presser
Knee
Feed
dog
height
Needle
Shirring device
DBx
Gauge
amount
bar
lifter
lifter
1
-----------
I
---------·
Maximum upper feed
Presser
foot
height
Use
Sewing speed 4,500spm
amount
Feed
dog
height
Presser
bar
lifter
Knee
lifter
Automatic
Needle DBX 1
Gauge Assembly$ Assembly B
bar
presser
lifter
Medium material Gathering
-003
6mm
-003
6mm
4,500
Smm
6mm
13mm
O.Bmm
#11
O.Bmm
6mm
13mm
6mm
#11
-006
Gathering
spm
Bmm
Assembly B
Included
-006
Bmm
When the upper feed amount
or
When
more,
When
more, or When
mm
use
or
the
a sewing
the
upper feed
more,
lower
feed
speed
amount
the
lower feed
use
a sewing speed
amount
Jess
3500spm.
Use
a maximum feed amount
than 6 mm
(assembly
(assembly
when a pucker
A)
or
pucker-control
C)
is
used
on model 082-8772-D
is
6 mm or more,
is
4 mm
than
3500
is
6 mm
amount
less
of
6 mm or
type
gauge
gauge
spm.
is
than
less
26.
or
4
Use
a maximum feed amount
or
pucker type gauge
(assembly
Sewing speed
Maximum Stitch length Smm
Maximum upper feed
Presser
foot
height
Feed
Needle
Thread
Thread
Automatic
C)
is
DB2-B7740
Use
Presser
Knee
Automatic
bar
dog
height
DBx
trimmer
wiper
Quick back
pr~sser
of
less
than 6 mm when a
(~ssembly
used
on model DB2-B772-•
amount
bar
lifter
lifter
presser
lifter
1 #11
bar
lifter
A)
or
pucker-control gauge
-423
Medium material Gathering
~I
-923
I
4,500spm
6mm
Minimum 10 mm
O.Bmm
0
13mm
Bmm
06.
-426
0
0
0
~I
I
Bmm
-926
0
-3-
Optional
equipment
I
Con
trol panel
E -20
E -
40
E -100
Ply sensor
E-RD
11-40
Piece counter
c
@
brother
c
EJ
P.
COUNTER
u
Th
e con
trol
Perspective
panels are optional.
Use
one
that
suits y
our
operation.
SENSORfi
-4-
MECHANICAL DESCRIPTIONS
III Upper shaft and needle bar mechanism
1)
Turning
to
2)
The thread take-up lever assembly
crank@.
3)
The needle bar
4) The needle bar
the
rotate.
machine pulley 0 rotates the upper
€)
is
driven via
f)
I attached
is
guided by
to
the
needle bar
the
needle bar bushings
clamp@
shaft@ I which
the
needle bar crank e attached
I moves
(upper)@
in
turn
causes
up
and
down.
and (lower) @.
the
thread
to
the
take-up
thread
crank @
take-up
l1l
Lower shaft and rotary hook mechanism
1)
Rotation
shaft@
2)
The
shaft e
3)
The rotary
of
to
motion
to
the
machine
the
vertical shaft bevel gear (upper)@ attached on
is
relayed
the lower
hook@
pulley 0 is
from
the
shaft via
is
driven in full revolutions by
the
transferred
vertical shaft bevel gear (lower) @ attached on
lower
shaft bevel gear
from
the
the
f)
lower
upper
shaft bevel
the
.
shaft@.
top
gear@
of
the
vertical shaft e.
attached on
the
bottom
of
the
the
upper
vertica l
-5-
[1]
Upper feed mechanism
1)
When
the
machine pulley 0 rotates
upper
shaft@
2)
The feed regul
rock arm
3) The
shaft
feed arm assembly
4)
The
backward.
The
5)
The eccentric wheel
feed
6)
The
lift
7)
The upper feed
up and
The
8)
The
a
upper
@,swinging
upper
upper
feed crank IDgui
lifting
upper feed
ing rock cran
down.
spring ®
combined movement
moves
ato
horizontally
feed rock shaft
the
upper feed rock arm a
r shaft assembly ® moves the horizontal feed connector @ attached
.
f)
the
upper feed rock arm (upper)
m.
feed arm assembly
des
assem
bly ® moves
rock
shaft
(f) and
the
lifting
k@.
lifting
of
the
rock arm ® moves
rock
crank@
presser bar
of
4) and
in
attached
ID
moves
the
upper
upper feed
moves
til
mo
ves
7)
operates
the
direction
to
the horizontal feed connec
the
upper
feed
bracket®.
the
upper feed
lifting
the
the
upper
the
pin
the
up
and down.
@,the
rock
upper
fnto
upper
of
the
arrow,
upper
feed brac
lifting
arm®.
feed connecting lever ®, swinging the upper feed
feed crank
depress
the
feed dog
the
eccentric wheel
tor
@ rotates
feed rock arm (lower)
ket
® and the feed dog ®
rock lever assembly
(9,
attached
upper feed crank
to
the
®.
@attached
to
the
the
upp
@,and
forward
@,swinging
upper feed
(9.
to
upper
er
feed rock
the
the
bracket
the
feed
upper
and
upper
@,
- 6-
lAJ
Feed
mechanism
@
@---
----
---------
@
~
1)
When the machine pulley 0 rotates in the direction
attached
2)
The
arm
3)
The
4)
The
backward.
5)
The
6)
The
7)
The
8)
The
9)
The
to
the
upper shaft@
level feed connecting dog 0 moves the level feed arm link assembly @,swinging the feed rock shaft
moves
the
level feed connecting dog 0 up and down.
<9.
feed rock shaft arm @
feed rock shaft & moves
eccentric wheel
vertical feed connecting rod
feed
lifting
feed
lifting
combined movement
rock shaft crank 0
rock shaft@
moves
CID
moves the vertical feed connecting rod
of
the feed rock shaft & .
the
horizontal feed bracket arm
4D
swings the feed
moves
4)
and
moves
the feed
the feed
8)
operates
lifting
of
the
ED,
4D
lifting
lifting
crank~,
the
feed dog @ attached
rock shaft crank 0 attached
rock shaft@.
moving
arrow, the level feed eccentric wheel @
moving the feed bracket
up and down.
the
feed bracket@) up and down.
to
the feed bracket
to
@)
forward and
it.
@).
-7-
~
Feed adjusting mechanism and quick reverse mechanism
The
upper
feed regulating plate assembly
1)
When
moving
2)
The angle
changes, changing
3)
For
Rotating
The
1)
When
moving
2)
The feed regulato r @ moves
feed
movement
3)
For
Rotating
The quick reverse mechanism
1)
When
linked
2)
The feed
®to shift
the
3)
When
the
the
upper
the
upper
of
the
the
movement
the
upper
length
control assembly
the
length
the
feed
regulator
of
the
movement
the
length
the
reverse lever ®
with
the
regulator
back
feed are reversed.
the
reverse lever ®
feed
to
the
feed
regulating
feed
regulator
feed
regulator
the
range
after
the
feed regula
control assembly @ rotates,
regulator@
@.
Then
the
feed rock shaft arm
after
the
control assembly@ changes
reverse lever shaft
lever
the
feed
regulator
normal feed.
plate
assembly@.
shaft assembly e attached
of
the
movement
horizontal feed
ting
plate assembly 0 changes
.
the
level
the
fulcrum
feed rock
is
depressed,
ID
@moves
is
the
sha
pressed back,
assembly 0 rotates,
of
the horizo
connector@,
the
feed regulator screw
regulator
of
the
connecting rod assembly
arm
lin
k assembly
®.
shaft
arm
®,
see
page 7
the
feed amount.
the
feed regul
moves.
feed
regulator
ft
assembly e and
the
upper
ator
lever (upper) {!)and
feed reverse spring ® changes
ntal feed
see
page 6
the
lever
the
feed
the
upper feed regulator
to
the
upper
connector@.
"[21
upper feed amount.
ID
move
"~
Feed
@,the
regulator
feed
Upper feed mechanism
fJ
moves
@,
s,
changing
mechanism
feed
the
feed
@.
regulator
forward
changing
11
•
regulator
regulator
Then
the
the
cam
@ rotates,
assembly @
II.
and backwa rd,
the
angle
of
the
range
lever (lower) ®
upper
upper
of
lever (lower)
feed and
feed and
the
the
-8-
(§]
Upper feed
mechanism
and
shirring
mechanism
(subclass
-006)
Upper feed amount
1)
When
moving the shirring lever
2)
The shirring lever 9 moves the upper feed regulator arm @),moving the upper feed regulator assembly @
and
Shirring
1)
When
shirring lever 9 moves
regulator
Rotating the upper feed regulating plate assembly (right)@) changes
2)
When
regulator
the
upper feed regulating plate assembly (left) 0 rotates, the upper feed regulator
e linked
the
feed regulator shaft assembly
Rotating the upper feed regulating plate assembly (left) 0 changes
the
shirring
assembly@, and
the
shirring
arm@)
wire
@ attached
the
upper feed regulator
the
wire
to
@
the previous positions.
with
the
upper feed regulator shaft@.
e.
to
the shirring lever 9
shaft@,
feed regulator shaft assembly
is
released,
the
spring
([.i)
is
pulled in
the upper feed regulator arm
6.
moves
the
the
upper feed amount.
the
direction
the
shirring amount.
shirring lever 9 and
cam
of
the arrow,
@,the
the
@ rotates,
upper feed
upper feed
the
-9-
111
Thread trimmer
1.
Thread
The
thread
knife
0,
@)
1 the movable knife holder e I the knife holder
presser
trimmer
clutch@ , and the thread trimmer solenoid@.
2.
Thread
trimmer
(1)
During operation
trimmer
trimmer
the
fixed knife
@ , the forked shaft
cam
lever assembly
trimmer
without
consists
@,the
operation (The five figures
the
of
lower
f),
the
rotary
the
movable
thread finger
@),
the
thread
thread
trimmer
hook
assembly.)
below
and on
the
next page show
the
thread
The
thread trimmer
trimmer
trimmer clutch@ I
The
from shifting.
(2)
When
activates, and
assembly
trimmer
solenoid @.
thread trimmer lever springiD
When
the
the
treadle
f),
secured by
clutch
cam
Because
the
movable knife holder e
thread trimming signal
is
heeled back and the thread trimming signal
presses
the
the
«D.
lever spring @
the
thread trimmer
presses
is
thread trimmer
thread trimmer
presses
received
cam
the thread trimmer
cam
does
not
the
thread trimmer lever 0
lever stud
cam
lever stud
lever assembly
function.
is
6).
The
roller bearing
6),
is
pushed above
cam
lever assembly
f)
does
not
to
prevent the movable knife holder 9
received,
the
thread
of
the thread trimmer
the
f)
against
engage
circumference
with
trimmer
of
the
thread
the
thread
solenoid @
cam
lever
the
thread
-10-
(3)
Movable knife holder action
By
the rotation
the roller bearing
The
motion
trimmer lever
The
movable
the fixed knife
(4)
Thread trimming complete stop
of
the lower shaft, the thread trimmer clutch @
is
transmitted
is
then relayed
4!1
connected
knifeO
@.
attached
to
the forked shaft@ via the thread trimmer
to
the
thread trimmer rod
to
the forked shaft@.
to
the movable knife hold
pushes
49
and the movable knife holder 0 via
ere
moves
the roller bearing up.
cam
lever assembly
in the direction
of
the arrow and overlaps
The
f).
motion
the
thread
of
When the thread trimming signal
trimmer
thread trimmer
original position.
The
original positions (in the direction
(S)
If
the movable knife 0
the thread trimmer clutch
the needle.
cam
lever spring
cam
thread trimmer lever spring
Thread trimming safety device
tiD
pushes
lever assembly
4D
does
not
@ automatically carry
is
not
received, the thread trimmer solenoid @ retracts and
the thread trimmer
f)
moves away from the thread trimmer clutch @ and returns
returns
of
completely retract,
the
thread trimmer rod
the arrow).
the
cam
lever assembly
49
the
pin
of
the thread trimmer
movable knife 0
f).
Then
the roller bearing
and
the movable knife holder 0
cam
lever assembly
to
a position where
it
does
the
not
thread
of
the
to
to
their
f)
and
strike
its
-11-
3.
Needle and bobbin threads trimming
(1)
When the needle
position, the rotary hook
formed by the needle.
rises
1.8
mm above its lowest
point
catches
the loop
------
(2)
When the thread trimming signal
thread trimmer
The
needle thread
and fed around the shuttle body.
clutch drives the movable knife.
is
caught by the rotary hook
is
received, the
-----
(3)
The
movable knife
and the loop spreading
(the upper shaft
shown in the figure above.
If
the
timing
thread trimming errors.
has
of
the movement
tip
enters the triangular loop formed by the rotary hook point under the needle plate,
occurs.
turned approximately
At
is
this
point
the thread take-up
330°),
and the needle thread
too
early, loop spreading
Bobbin thread
is
is
raised
slightly above its lowest position
is
spread by
not
performed properly which results in
the
movable knife
Movable
knife
as
As
seen
with
the fixed knife removed
(4)
The
needle and bobbin threads caught by the movable knife in step
movable knife and the lower thread finger
approaches the
When the movable knife
tension
to
top
prevent
of
its stroke.
is
excessive
spreading the needle thread, the tension release relieves
tension and
to
be
cut by the fixed knife tip.
to
enable the needle thread
-12-
(3)
are gradually spread by
At
this time, the thread take-up
to
be
extended smoothly.
the
needle thread
the
liD
Tension release
1)
The
thread trimmer solenoid 0 operates when the thread trimming signal
2)
The
solenoid lever
releasing
3)
The
releasing
4)
The
5)
The
6)
The
7) When the thread trimming signal
the tension releasing wire
(The
NOTE:
m:J
Thread
lever@.
tension releasing wire 0 relays the motion
plate@.
thread tension releasing plate@
tension releasing stud@
tension disc
tension releasing spring
When the
tension releasing
When the
releasing
wiper
@,
attached
presses
presser@)
presses
0 return
4D>
forces the tension releasing lever@ all
presser
presser
plate@
foot
is
plate@.
foot
is
to
its original position.
(subclasses -400, -900)
0
to
the
end
of
the
thread trimmer solenoid
of
the tension releasing lever
presses
up the tension release pin
up
the
is
not
to
raised by the knee lifter,
The
lowered, the presser
the tension releasing stud
tension
received,
their
subsequent action
discs@).
the
solenoid lever@, the tension releasing
original positions.
lifter
1)
2)
3)
4)
is
received.
0,
pushes
@to
the thread tension
@.
fj
and
the
tension
the
way back.)
the
knee
lifter
lifting
is
the
same
as
steps
lever spring 0 returns the thread tension
When the thread wiping signal
thread trimming
solenoid
The
crank assembly
thread wiper rod
The
thread
thread.
When the thread wiper signal
the thread
wiper solenoid
0 lifts the thread wiper rod@.
thread
thread
wiper
is
wiper
@,
@.
wiper
crank assembly @, wipes
wiper
0
disc
presser@).
lever
G)
4 through 7 above.
completed, the thread wiper
rod @ drives the thread wiper
attached
0,
attached
spring @ returns the thread
to
its original position.
the
lever@
presses
to
the
is
received after
the end
to
the
end
is
not
received,
tension
and
thread
of
the
of
the
the
-13-
I1W
Automatic
presser
bar lifter
mechanism
(subclass
t
-900)
1)
2)
3)
4)
The
presser
when
The
presser
lifting
The
knee
lifter
The
presser bar
the
knee switch
link
9.
lifter
lever & I
foot
lifting
foot
lifter
complying bar
the
knee
0)
and the presser
solenoid 0 moves the
is
pressed.
regulating rod @
@)
moves up the presser bar clamp
lifter
connector@) and
foot
pushes
4fl
attached
1
link
the
up
knee
to
joint
@ and the presser
the
knee
lifter
lifter
lifting
the
presser bar clamp
foot
complying bar
4ID
via
the
knee
lever
€>.
(@I
are lifted.
lifter
regulating rod @
@)
via the presser
lifter
bar
€)
the
1
foot
knee
-14-
lD1
Lubrication
1.
Upper shaft lubrication
mechanism
1)
Oil fed by the pump body 0 flows
lubricate the upper shaft bushings (left) @ and (right)
body lubricates the feed regulator.
2)
Because
is
3)
The
oil clogging and over-lubrication.
4)
The
5)
The
pump body 0 via the
the oil regulating valve ~ is
lubricated through the thread take-up crank and the needle bar crank.
thread take-up lever
oil cap@ attached
oil which
is
collected in the portion
is
lubricated through the
at
the
upper shaft's right edge prevents oil from being
felt
and the wick.
into
the upper shaft through the upper shaft bushing (middle) @
9.
The
oil sprayed inside the vertical portion
attached
of
at
the
the
felt
body
left
edge
attached
with
of
the upper shaft, the thread take-up body
to
the needle bar crank.
the needle mechanism
-15-
shed
outside
is
transported
The
the
of
felt
prevents
machine.
to
to
the
the
2.
Lower shaft lubrication
0
Arm channel
Lower shaft
1)
The
oil fed
2)
Some
hook.
The
oil
3)
The
oil absorbed by the wick lubricates the feed rock shaft@ and the feed
4)
The
feed rock
3.
Pump mechanism
By
means
attached
the pump through the center hole.
the lubrication tubes through the ports
body.
The
oil collected in the portion
the needle mechanism
the pump
by
the pump 0 lubricates the lower shaft and the lower shaft bushing (left)@.
of
the oil
shed
oil sprayed inside the vertical portion
of
the rotation
at
the vertical shaft bottom, oil
plunger.
at
the
lower shaft bushing (left) @ flows through the lower shaft
from the lower shaft bushing (left)@ returns
shaft@ and the feed
of
is
drawn
lifting
the pump propeller 0
The
of
the body @
to
the pump body by
to
the oil pan.
of
the body lubricates the lower shaft bushing (right)
rock shaft e through the arm channel.
is
drawn
oil
of
the pump
is
fed
with
to
to
lifting
to
lubricate
rock shaft
e.
the
rotary
8,
the
-16-
DISASSEMBLY
[]]
Machine covers
1)
Remove
2)
Remove
3)
Remove
4)
Remove
5)
Remove
6)
Remove
7)
Remove
For a sewing machine
Before removing
Remove
the
screw 0 and
the
three screws@), then remove
the
four
screws@,
the
six screws@),
the
screw@ and
the
two
screws
the
screw(;) and
with
the
the
three screws ~ and
the
needle@.
then
then
remove
the
thread take-up cover@.
49
and
the
the
upper tension regulator assembly
automatic thread
rear cover
4ID,
the
the
remove
the
oil stopper
face plate e and
the
upper cover
rear cover
plate®.
4ID
and
fl
the
and
the
the
rear cover packing {I).
49.
trimmer:
remove stop ring E® ,washer@ and
solenoid bracket
fD.
face plate packing@.
upper cover packing@.
-17-
the
connecting pin
W.
111
Presser
1)
Remove
2)
Remove
3)
Loosen
upper feed crank).
4)
Remove
5)
Remove
6)
Loosen
7)
Remove
the regulating
the presser spring 9 and the adjusting screw
the
the
the screw @ and
the
the presser bar 0 from the arm top.
foot
screw @, and
screw
mechanism
nut
0 and
rem~:>Ve
the
pin 6 and the spring @ .
the
presser
ID
.
Remove
the
presser
the
upper feed bracket assembly
bar bracket thread guide
the presser bar clamp@ by lowering
regulating
@).
dial@.
4ID
.
@)
(presser foot, upper feed dog and
the
presser bar 0 .
llJ
Upper feed
1)
Loosen
2)
Remove
3)
Loosen
remove
4)
Loosen
5)
Loosen
upper feed rock
mechanism
the
screw 0 and remove connecting stud (lower)@.
the
two
screws@),
the screw
the
upper feed arm assembly@ and the washer@).
the
four
the
screw (D.
@).
screws
shaft~
then remove
By
inserting
4ID
.
By
inserting the screwdriver
and
the
upper feed rock arm (upper)
the
the
screwdriver
upper feed connecting lever 9 and the crank assembly@.
into
into
0
the notch
the notch
~.
of
the
upper feed rock arm (lower) & ,
of
the feed rock shaft
0,
0
remove
the
-18-
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