JUKI MB-372 User manual

I.L^.
MODEL
MB-372
HIGH SPEED
SINGLE THREAD CHAINSTITCH
BUTTON-SEWING MACHINE
Instruction Book
TOKYO JUKI INDUSTRIAL CO..LTD.
From the library of: Superior Sewing Machine & Supply LLC

CONTENTS
Page
1. GENERAL DESCRIPTION 1
2. SPECIFICATIONS 2
3. NAMES OF PARTS 3
4. CAUTIONS BEFORE OPERATION 4
5.
LUBRICATION 4
6.
MOTOR PULLEY AND BELT 5
7.
NEEDLES 6
8. INSERTING THE NEEDLE 6
9. THREADING THE MACHINE 7
10. THE THREAD TENSION 8
11. FUNCTIONS OF THE THREAD PULL-OFF LEVER 8
12. THE THREAD NIPPER 9
13. ADJUSTING THE NEEDLE BAR 10
14. TO PRODUCE OPTIMAL STITCHING CONDITION 12
15. POSITION OF THE NEEDLE GUARD 14
16. TIMING THE NIPPER RELEASING PLUNGER OF
TENSION DISC NO. 2 14
17. CHANGING THE POSITION OF THE BUTTON TRAY ••• 15
18. STITCH SELECTING -15
19. HEIGHT OF BUTTON CLAMP 17
20. ADJUSTING THE BUTTON CLAMP PRESSURE 17
21. ADJUSTING THE BUTTON CLAMP STOP LEVER 18
22. ADJUSTING FOR 2-HOLES AND 4-HOLES 18
23. CHANGING THE BUTTON HOLDING CLAMP AND
ADJUSTING ITS HEIGHT 19
24. CAUSES OF MALFUNCTIONS AND REPAIRING 21
25. ATTACHMENTS TO MB-372 BUTTON ATTACHING
MACHINE 21
( i ) How to install the snap fastener attachment 22
(ii) How to install the wrapped-around button clamp attachment 23
(iii) How to insall the shank button clamp attachment 25
{iv) How to install the metal shank button clamp attachment ••• 27
From the library of: Superior Sewing Machine & Supply LLC

1. GENERAL DESCRIPTION
JUKI Model MB-372 is a single thread, chain stitch, button sewing
machine. It is widely used to attach flat two hole or four hole buttons
as well as snap fasteners, shank buttons and metal shank buttons. This
is an ideal machine to attach these buttons on all knit goods, men's
shirts, work uniforms, ladies' suits and men's suits.
This machine is equipped with 8 stitches, 16 stitches and 32 stitches
and these stitches are interchangeable without changing the stop motion
From the library of: Superior Sewing Machine & Supply LLC

cams. A speed slowing device, an exclusive JUKI attachment, is
incorporated into this machine and consequently loosening of screws or
malalignment of stitches which sometimes characterize amachine with
a stop motion mechanism is completely eliminated and assures a safe
and stable stitching condition.
2. SPECIFICATIONS
Model
Sewing type
Sewing fabric
Sewing speed
Button-sewiniar
Needle bar stroke
Needle
Stitch number
Feed length
Button size
Presser bar life
Button clamp lift
Thread nipper
Stop motion
Lubrication
Power required
Lubricating oil
2.hole button
4-hola button
MB-372
Single thread chainstitch button-sewing
Knit goods, shirts & working wear etc.
Max. 1500s.p.m.
1 Lengthwise feed 0 2-hole button
2Lengthwise/crosswise feed ••• 4-hole button
3 By attachment Snap, Shank, Metal
shank or Wrapped round
48.6 m/m (1-7/8")
TQx7 (175x7) or TQxl) (175x1) #14-#18
8, 16, 32, Gam: not to be changed
6, 12, 24, Cam: to be changed
Crosswise feed •••2.5~6.5 m/m (3/32~l/4")
Lengthwise feed ••-0^2.5^6.5m/m (0~3/32~l/4")
Dim: 10-27 m/m (3/8-1-1/32")
Std. 12 m/m (15/32")
Automatic or foot operated
2-way cam type
Automatic (with speed-slowing device) type
Hand oil type
200 W
New Defrix Oil No. 1 & New Defrix grease
Snap
Shank button
W
Metal sbankbutton
Wrapped round button
From the library of: Superior Sewing Machine & Supply LLC

3. NAMES OF PARTS
m
® Needle bar (§) Nipper block (|i) Needle bar lever ® Thread pull-oft^
lever (D L shaped thread guide ® Tension disc No. 2 0 Tension
disc No. 1 (D Nipper bar 0 Thread guide No. 1 @ Nipper bar
actuating lever @ Machine arm @ Button clamp lifting link
Needle bar lever connecting rod (Q) Lengthwise feed graduated plate
(!|) Stop motion disc spring (g) Rubber washer ® Stop motion disc
applying pressure lever @ Needle driving pulley @ Stop motion disc
@> Ball joint eccentric @ Loopershaft tube (§) Crosswise feed graduated
plate @ Loop positioning finger cam, rear @ Loop positioning finger
cam, front @ Looper @ Button clamp leverjaw @ Feed plate
@ Needle plate @) Needle @) Button clamp lifting rod (0) L shaped
button clamp lifting rod @ Tension disc No. 3 @ Thread guide No. 3
@ Needle bar bearing block & thread guide @ Nipper releasing plunger
knurled thumb nut (g) Button clamp pressure adjusting spring nut
— 3 —
From the library of: Superior Sewing Machine & Supply LLC