Juki LBH-781, LBH-782, LBH-783, LBH-784 Instruction Manual

BE078130B0A

Before stitch

struction

operite

operating

Machine,

Book

it in

carefully

the

your

please

correct

JUKI

read

in

and

Lock

this

order

efficient

In

to

HIGH

BUTTON

CAUTION

1.

The

machine

from

the

opposite

MODEL

SPEED

SINGLE

HOLING

Instruction

IN

OPERATION

should

rotate

pulley.

Take

direction.

care

LBH-781-782-783-784

NEEDLE

SEWING

LOCKSTITCH

MACHINE

Book

counterclockwise

nottorotate

as

the

machine in

observed

2. Never start the machine before filling the machine base

with

lubricating

3.

Remove

machine before performing

4. Clean up trimmer

levelofthe

1.

MOTOR

the

bobbin

the

every

lubricating

oil.

case

sewing'

day

after

PULLEY

oil.

and

the

hook

sewing

the

trial and

needle

operation.

the

work.

AND

thread

bobbin

Also

check

V

from

thread

BELT

the

STRIAGHX

SPECIFICATIONS

LBH-781

Application

Sewing

speed

Buttonhole

length

Bar-tack

Needle Presser

Lubricating oil

width

lift

Buttonholing

6.4~19.0mni

(l/4"~3/4")

mrATn''\

LBH-782 LBH-783 LBH-784

for

Max.

6.4~25.4mm

(1/4"~1")

DPx5

12mm

JUKI

New

ordinary

3,600

cloth,

s.p.m.

6.4~31.7mm

,i®/4"-l-l/4")

-S.Omin

#11~#14

{15/32")

Defrix

(3/32"~3/l

Oil

No.

knit,

12.7~38.0m

(l/2"-I-l/2

1

etc.

6")

1. Motorsof300W, 4-pole are used for single-phase or three-phase

operation.

at

3,100

M-typeVbelts

2.

a 250W

s.p.m.orless.)

are

used.

motor

has to be used, operate the machine

(If

3. Refer to the following table for the motor pulleys, V belt length,

and

sewing speed.

Low

Sewing speed

3,600

s.p.m.

3,400

s.p.m.

3,100

s.p.m.

2,900

s.p.m.

(V

belt

Part No.: MTJ-VMOODDOO, V

Frequency

Motor

pulley Part No.

B7262-781-000 B7263-781-000

B725

B7257-781-000

B725

B7254-781-000

B7258-781-000 B7259-781-000

6-781-000

3-781-000

belt

length)

High speed

Vbelt

44

inch

43

inch

44

inch

42

inch

43

inch

42

inch

42

inch

41

inch

Vbelt

42

42 43 42

42 42

42

speed

inch

inch inch inch

inch inch

inch

i

* Howtoinstall

Place

motor

pulley 0

flat part © of the

setscrew o

Then

motor

into

motor

securely

i

pulley

the

motor

shaft so

shaft aligns with first

tighten

setscrews0and

that

*

How

to

install

V

belt

1. Mount high-speed V belt O oti accelerating pulley 0 and the large diameters of the motor pulley.

2. Mount low-speed V belt 0 on low-speed pulley 0 and the smalldiameters of the motor pulley.

3. By moving

when

4. Move

their

the

middle

motor

portions

pulley

from

side to side, adjust

are

and

pushed

forth

back

the

lightlybyhand.

tensionofV belts 0 and 0 so

to align V belts 0 and

that

they

0.

Motor

pulley

give an approx. 10 mm slack

2.

SETTING STAND

UP

THE

THREAD

3.

SETTING

MACHINE

UP

HEAD

THE

Assemble

lock

pass

4.

1. Removing screw0,remove spring 0 from

the

thread

nut

O to fix

the

power

cable tl*iOugh

ATTACHING

stand,

and

fix it in

the

thread stand. If ceiling wiring can be made,

spool

THE

rest

the

table

rod

0.

FLAT

•iiiiiiiiliii'iiiiii

hole.

Then

BELT

the

suspension screw.

tighten

Putting cushion 0 into hinge0,insert hinge O into

the

machine

the

machine

2. Pass belt 0 through belt shifter 0 so that the belt rotates in arrow o direction.

3. Reinstall screw 0 and spring

0.

4. Lift tripping lever 0 in the direction, pass the belt between latch B 0 and latch A

5. Passing

6.

Put

(NOTE) Some expansion or contraction In

belt

shifter 0 of

fixing pawl 0 in

the

belt. However,

the

speed

transmitter,

second

groove

belt

will restores its original length while In use.

attach

the

belt

from

the

bottomofratchet

the

belt caused by temperature or humidity may make It rather difficult to Install

onto

tension pulley 0 .

0

to

provide

head.

Then,

place

the

machine

base.

head

on

i

0.

the

belt

with

tension.

5.

INSTALLATION/REMOVAL

OF

BELT

Aligning guide pin 0

belt For

direction

COVER

coverinthe removalofthe

oppositetothe

arrow

belt

with

hole 0 in belt cover0,push

direction

cover,

arrow,

untilitsnaps.

bring

down

and

slideitup.

the

belt

coverinthe

the

6.

LUBRICATION

★

Before

1.

Fill

Defrix Oil No. I up to the level indicated by

2.

Supplement

the

3. When seen to

(Low

lubricating

Starting

the

oil

bottom

the

machine has been properly lubricated,

run

speed

the

machine;

reservoirofthe

the

oil

when

line of oil gauge

through

operation

oil.)

the

permits

machine

the

oil

0.

pipe from oil sight window

easier

base

with

"HIGH",

level has

lowered

observationofthe

JUKI

the

Drain dirty oil by loosening oil drain screw 0 , and fill

the

oil

reservoir

with

fresh

oil.

New

below

oil is

O.

*

Adjusting

Adjust

hook

by turning oil adjusting screws O for rough adjust

the

volumeoflubricating

lubrication

for

the

sewing

oil suppliedtothe

hook

sewing

ment, and 0 for fine adjustment; oil volume is reduced

when

*

1.

2.

turning

Other

Apply

points

Apply

point

use

the

screws

lubricating

oneortwo

onceaweekorevery

twoorthree

when

foralong

dropsoflubr'ijating oiltothe

the

machineisnewly

time.

clockwise.

points

other

drops of lubricating oil

week.

setupor

has

only

been

arrowed

to O

out

of

7.

★

Turn

HOW^TO

THE

off

NEEDLE

the

motor

INSTALL

power.

Use a

DPx5

needle.

1. Loosening needle setscrew hold needle O

with

2.

3.

10.

its recessed

insert

the

hole,

and

securely

tighten

ATTACHING

needle

part

the

fully

needle

facing

into

toward

the

needle

setscrew.

THE

the

operator,

clamping

BOBBIN

1.

Hold

and

place

bobbin

bin bobbin counterclockwise.

2.

Passing

through

O of

case,

and drawn

thread

ing

winder

^

Set

it

direction bobbin

pulled.

into

case

so

the

thread

the

pull

the

thread

out

outlet0,pass

under

tension

the

bobbin

rotates

in

is

the

when

thread

the

that

wound

bobbin

thread,

bobbin

the

bob

thread

outlet

can

from

spring.

so

that

arrow

the

INSTALLATION/REMOVAL

BOBBIN

9.

WINDING

Bobbin

winder

a

be

tension

bracket

-^1

Bobbin

-

winder

trip latch /

X J I

is

CASE

Adjusting

!

screw

11

/

Adjusting

THE

nut

1.

Lift

up

latch

lever O

gers

to

hook.

off

the

latch

lever is lifted

2.

For

installation

case,

push

the

hooksothat

by

the

snapinthe

BOBBIN

1.

Fitabobbin

winder

2.

Take

the

and

passitthrough

in

the

in

the

of

the

around

3.

Push

the

latch

in

and

the

4.

Loosening

perform

ing

in

screw

wound

5.

If

the

evenly,

the

bobbin

bracket

winding.

and

remove

A

bobbin

the

hook

latch

shaft.

thread

numerical

figure,

thread

the

bobbin.

bobbin

the

bobbin

the

adjustment

or

so

that

about bobbin

adjust

for

hold

bobbin

between

it

does

case

up.

of

bobbin

it is

shaft,

lever.

onto

from

order

and

wind

several

winder

arrow

willbewound.

adjusting

out

the

four-fifths

is

the

winder

proper

OF

two

from

not

while

the

bobbin

case

supported

and

the

bobbin

the

guides

shown

the

direction,

by

screw

adjusting

bobbin

wound

position

tension

and

case

fin

the

fall

the

into

then

spool

end

turns

trip

nut,

is

full.

un

of

even

11.

1. Pass

2.

The supplied

THREADING

r©/.

the

needle

with

threadinthe

canbedone

the

machine.

threading

THE

NEEDLE-THREAD

--

orderasshowninthe

easily

by

using

the

figures.

needle

threader

12.

•k

1.

2.

★

1.

REDUCTION

SEWING

EMERGENCY

Reductionofsewing

Turn

hand

stop

crankOdownwardstoposition

O,

and

the

machine

Emergency

Turn

the

willbeimmediately

stop

hand

stop

OF

SPEED

STOP

speed

crank

downwardstoposition

2.

the

machine

(NOTE) When

will

stop

the

hand

pushItdown.

immediately.

stop

crankdonot

AND

slowed

down.

return,

13.

When stop

broken,

mechanism.

(NOTE)

15.

MANUAL

you

wandtofeed fabric

or

to

rotate

Confirm turning

TYPES

(Whip

stitch)

mmwmmimmimMimm

(Purl

stitch)

resume

manual

sewing

FEED

from

HANDLE

manually

the

after

pointatwhich

feed handle O to operate

that

the

needle

does

the

manual

OF

feed

STITCHES

Pallarel side seam Bar tacking seam

not

handle.

giving an

stickinfabric

the

emergency

thread

cloth

was

feeding

before

14.

HOW

DESCENDIIMG

m

When

you

do ,

becauseofthread

keep

on

pressing

until

the

machine

descend.

This

machineiscapableofforming

stitches,

(Whip stitch)

The

thread

bottom.

(Purl When ittopass the

center

namely

whip

onlyontopoffabric,

stitch)

applying

bobbin

line.

whip

stitchisformed

higher

straight

thread

through whichispulled

stitch

tensiontothe

TO

HOLD

not

wanttocut

breakageorsome

down

knife

stops.

Then

and

purl

in

zigzag

and

the

fabric,

the

over

fabric

stop

the

two

different

stitch.

showing

bobbin

needle

threadtopermit

purl

stitchisformed

from

both

THE

KNIFE

after

sewing

other

reasons,

lever O lightly

knife

will

not

types

of

the

needle

threadonthe

by

sidestothe

Juki LBH-781, LBH-782, LBH-783, LBH-784 Instruction Manual

Specifications and Main Features

Frequently Asked Questions

User Manual