Singer 471U User manual

SERVICE MANUAL
FOR
SINGER MODEL 471U
THE SINGER COMPANY
From the library of: Superior Sewing Machine & Supply LLC

CONTENTS
(C MECHANISMS 1) 1
|T| Needle bar mechanism 1
m Rotary hook mechanism I
ITj Needle zigzag mechanism 2
|T| Feed mechanism 3
m Clutch mechanism 4
B Cutter mechanism (1) 6
B Cutter
mechanism (II) 7
[Tj Upper thread cutter mechanism 8
B Lower thread cutter mechanism 9
[lo] Presser bar lifter mechanism 9
Tension releasing mechanism 10
fll]
Clutch and brake 29
fi2] Cutter safety device 29
[III Needle bar 31
ini Rotary hook shaft 32
[i^ Upperclamping foot and lower
thread cutter 33
[I^ Base needle plateand cutter
position control 34
Oil Upper clamping foot position control ... 35
M Rotary hook 35
[li] Lubrication 36
[2ol Needle sidewise movement
adjustment 36
(HI Needle zigzag reference
position adjustment 36
HH Scissors assembly position control 38
HD Scissors guide position control 38
[24] Covers 39
((ADJUSTMENtH) 40
Needle sidewise movement
adjustment 40
Needle bar and rotary
hook adjustment 40
Upper clamping foot lifter
adjustment 42
Cutter adjustment 44
Buttonhole width and reference
position adjustment 46
Upper thread cutter adjustment 48
Lower
thread cutter adjustment 50
Movable knife and fixed
knife adjustment 50
((DISASSEMBLY PROCEDURES)).
m
m
m
B
B
B
m
B
Covers
Lower thread cutter
Presser
Rotary hook
Upper thread cutter
Length feed
Clamping foot
Cutter safety device
[9] Clutch and brake
U
un
M
M
0
Feed
Needle bar
Cam relay
Upper shaft
Auxiliary
shaft
Needle zigzag
Needle breakage detection
Cutter
Lower shaft and rotary
(C ASSEMBLY PROCEDURES 1
B Lower shaft
U] Cutter
IT] Thread breakage detection
[Tj Needle zigzag
[Tj Auxiliary shaft
|T| Uppershaft
m Cam relay
(D Feed
rri upper clamping foot
flo] Upperthread cutter
14
m
15
15 m
16
16
m
17
17
m
18 m
18
19
m
19
m
m
20
m
21 M
0
21 mi
21
23
p]
23
24
26
27
(Hj
27
28
Qzl
28
OH
Belt shifter adjustment 52
Lubrication
adjustment 53
Tension pulley
adjustment 54
Bobbin winder
adjustment 54
Main tension and auxiliary
tension adjustment 55
Thread breakage detection
adjustment 56
Adjustment for changing the
stitch number 57
Cutter safety device adjustment 57
Adjustment of feed cam segment 59
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(MECHANISMS ))
[T] Needle bar mechanism
&
When the pulley O rotates in the direction of the arrow, this movement is transmitted to the thread take-up
crank O fixed on the end of the upper shaft O-
The needle bar crank O is fixed to the thread take-up crank O, andan up-down motion is transmitted tothe
needle bar clamp O through the needle bar crank rod 0.
The needle barO is fixed to the needle bar clamp 0 and is guided by the vertical bushing on the needle bar
support 0 so that is moves smoothly up and down.
[T] Rotary hook mechanism
0
0
00
0
1. When the pulley 0 rotatesinthedirection ofthearrow,this movement istransmitted tothetiming pulley U0
fixed on the upper shaft 0.
2. The timing belt0 is wrapped around the timing pulley U0 and assures sure transmission of the rotating
movement of the upper shaft to the timing pulley D 0.
3. Thetiming pulley D0 is fixed to thelowershaft0 and transmitstherotating movement tothelowershaftgear
0 fixed to the end of the lower shaft 0.
4. The rotary hook shaft gear0 mesheswith the lowershaft gear 0, and therotating movementistransmitted to
the rotary hook shaft 0.
5. The rotating hook assembly 0 is fixed on the rotary hook shaft 0 and rotates completely.
- 1 -
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|T| Needle zigzag mechanim
DilQvi
1. Whenthe pulley O rotates in thedirection ofthe arrow, the rotating movement istransmitted to the reduction
gear O fixed on the upper shaft Q-
2. Thereduction gear© meshes with thesubshaftgear reduces therotation oftheuppershaft© by half, and
transmits this motion to the sub shaft ©.
3. The needle zigzag cam © is fixed to theauxiliaryshaft ©, and the triangular portion of the needle zigzag cam
fits in the needle zigzagforked link ©.
4. The upper end of the needle zigzag forked link © is fitted on the needle zigzag link ©, and an oscillating
movement is transmitted to the needle zigzag lever R © linked with the lower end of the needle zigzag forked
link ©.
5. The needlezigzaglever F © isfixed on the needlezigzagleverR © and causes the needlebarframe slideblock
o fitted on the end of the needle zigzag lever F © to oscillate.
6. The needle bar support slide block © fits in the groove of the needle bar support © and causesit to oscillate
back and forth.
-2-
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Q] Feed mechanism
0
1. When the upper shaft O rotates in the direction of the arrow, the worm O fixed to the upper shaft O also
rotates.
2. The worm wheel O meshes withthe worm o ,and therotating movement istransmitted tothe worm wheel shaft
o
3. The change gear R0 attached to the end of the worm wheel shaft O meshes with the change gear O, which
causes the change gear shaft 0 to rotate.
4. The free wheel gear 0 fixed on the change gear shaft 0 meshes with the feed cam 0 causing it to rotate.
5. The roller 0 attached to the end of the feed adjusting lever 0 fits inthe heart-shaped groove ofthe feed cam and
causes the feed connecting rod 0 to move back and forth using the feed adjusting lever shaft 0 asa pivot point.
6. The end of the feed connecting rod 0 is linked to the feed drive shaft arm pivot point 0 and causes the length
drive shaft feed arm 0, clamping foot 0, and length feed plate 0 connected to the feed drive shaft arm pivot
point 0 to move back and forth.
ffiGear ratios
Change gear R
1 /30 rotation
1 rotation
Change gear L
1 reduction gear
1 rotation
2 rotations
1 /2 rotation
'J
Bychanging the gear ratio (change gear combination) of the upper shaft rotation with respect to one rotation
(one cycle) of the feed cam, the number of stitches can be varied between 58 and 347.
-3-
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U] Clutch mechanism
O
1 Starting
1. When the starting leverO islowered inthe direction of the arrow, it pressesagainst the lowerend of the clutch
lever causing it to pivot on the clutch lever shaft O ^nd move in the direction of the arrow.
2. When the clutch levere moves in the direction of the arrow, the stop leverclawO fixed on the stop lever0
rises to mesh with the clutch claw O fixed on the clutch lever 0
3. The belt shifter drive lever0 isfixed on the end of thestop lever 0, and the beltshifter roller 0 attached to the
lower end of this moves the top side of the belt shifter cam 0 attached to the belt shifter lever 0.
4. The belt shifter lower 0 linked to the belt shifterlever 0 moves in the direction of the arrowto shift the flat belt
to the low-speed pulley.
II Belt shifter
The belt shifter U 0 and the belt shifter lower 0
fixed to the clutch lever are linked to the movement
of the clutch lever and shift the flat belt between the
high-speed pulley and low-speed pulley so as to
transmit a stable rotation to the machine.
0-^ 1)1
/// // High-speed pulley
-4-
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III Stopping
1. When thestopcamcontact plate0 fixed tothestop lever comes incontact with thestopcam segment B ®, the
stop lever tongue O moves one step away from the clutch tongue O-
2. When thestopcamcontactplate0 fixed to thestop lever 0 comes incontactwiththestopcam segment A 0,
thestop lever tongue 0 moves away from the clutch tongue 0, and the clutch lever returnspring moves the
clutch lever 0 backinthedirection ofthearrow.Theclutchstopper0 entersthe groove onthestopcam0 and
stops the machine.
IV Emergency stopping
1. When the emergency stop arm 0 is pushed down,
the tongue of the emergency stop lever 0 meshes
with the clutch tongue 0, and the machinegoesto
slow-speed operation.
2, When the emergency stop arm 0 is released, the
tongue of the emergencystop lever0 movesaway
from the clutch tongue
0, and the machinestops.
-5-
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Ul Cutter mechanism (I)
0
0
1. When the sub shaft O moves in the direction of the arrow, the cutter eccentricrod O fitted to the cutter
eccentric wheel O fixed on the sub shaft oscillates.
2. The cutter drive lever O is linked to the end ofthecutter eccentric rodO andso oscillates inthe same way.
3. When thecuttercam segment 0 attachedto the feed cam pushed against thecutterpushbar 0, the clutch 0
riding on the clutch collar 0 moves to the clutch set collar 0.
4. When the cutter push bar 0 movesaway from the cutter cam segment 0, the clutch 0 falls in between the
clutch collar 0 and the clutch set collar 0.
5. When this happens, the cutter drive lever 0 entersthe dent in the clutch 0 and lifts it up.
6. Thelowerendoftheclutchis linked tothecutteroperationarm0 andcausesthecutteroperationlink0 linked
to the end of the cutter operation arm 0 to move up and down.
7. Thecutter holder0 islinkedtothecutter operationlink 0, and thecutteroperationshaft0 fixed tothecutter
holder 0 is moved up and down.
-6-
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|T] Cutter mechanism (II)
I Cutter drop prevention mechanism during thread breakage
I. Whenthe needlethread breaks, the thread breakage perceivingleverO automaticallycomesdown,and theend
ofthecutter clutch stopper O fixed to the thread breakage perceiving lever shaft O catches onthepinofthe
clutch O and stops the cutter from falling.
Stop cam tab A
Thread take-up lever link
Lever
II Cutter drop prevention mechanism during high-speed operation
1. When the clutch lever rises, the cutter stop connection rod 0 is pushed in the direction of the arrow, and the
movement is transmitted to the cutter stop lever O linked to its end.
2. The cutter stop levershaft O is fixed to the cutter stop leverO and transmits the movementto the stop lever
bracket O.
3. The clutch stop leverbracket O fixed to the stop leverbracket O ismoved inthe direction of the arrow. This
holds the pin of the clutch O and locks it securely in place, thus stopping the cutter from dropping.
-7-
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U] Upper thread cutter mechanism
Clamping
Cutting
thread
Scissors U
&
Clamping foot
1. Whenthe presser bar lifterconnectingrod O movesinthedirection ofthe arrow, presserlifter0 drops down in
the direction of the arrow pivoting on presser lifter lever shaft O.
2. The trimming clutch guideO isfixedon the end of the presser lifter ^nd the clutch cam0 isfixedon this and
drops down in the same way.
3. When the clutch cam 0 comesaway from the trimming clutch plate O, the upper thread trimming leverO is
moved in the direction of the arrow by the scissors operating spring O.
4. The upper thread trimming lever B O is fixed to the end of the upper thread trimming lever 0, and the
movement is transmitted to the scissors D 0 fixed on the upper thread trimming B O.
5. The scissors M 0 attached to the scissors D 0 come in contact with the clamping foot, and the scissors M0
close to cut the needle thread.
6. The scissors guide 0 fixed on the length feed arm advances in the direction of the arrow when the machine is
started, and the scissors M 0 open.
-8-
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U] Lower thread cutter mechanism
O0
1. When the lowerthread cutter leverO movesinthe direction ofthe arrow, the lowerthread cam leverO fixedon
the lower thread cutter lever O moves in the direction of the arrow.
2. The roller attached to the end of the lowerthread cam leverO fits inthecam grooveon the lowerthread cam
O and moves the lower thread cutter link 0 back and forth.
3. The thread cutter driving lever 0 is linked to the end of the lower thread cutter link 0 and this transmits a
circular movement to the thread cutter driving lever 0 using the stud screw 0 as pivot point.
4. The lowerthread retainer 0 and the lower movable knife 0 are fixedon the thread cutter driving lever 0, and
the lower movable knife 0 and lower fixed knife 0 come together to cut the thread.
Presser bar lifter mechanism
0
0
1. When the lowerthread trimming lever0 movesin the direction of the arrow, the presserbar lifterconnecting
rod 0 transmits the movement to the presser lifter
0.
2. The presserlifter0 is fixed tothe presserliftershaft0 and moves thepresserbar lifter0 fixed totheendofthe
presser lifter shaft 0up and down.
3. The presser bar lifter link0 islinkedto the presserbar lifter 0, and the bottom of this islinkedto the presser
bar clamp 0 and moves it up and down.
4. The presserbar 0 isfixedon the presserbar clamp 0 and causesthepresserfoot rollerunit0 connectedto its
bottom to move up and down.
5. The feedarm support 0 fixed to the length feedarm 0 catcheson the presserfoot roller unit0 and movesthe
clamping foot 0 up and down.
-9-
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ini Tension releasing mechanism
00
O
0
1. When the tension releasingcam segment F O attached to the feedcam pushesagainst the tension releasingpin
thetension releasing leverS0 fixed onthetension releasing lever O pivotsonthestud screw 0 and pushes
against the tension releasing pin 0.
2. The tension releasing pin 0 pushes against the tension releasing disc 0 and releases the auxiliary tension (f).
3. Whenthe clutch leverenters the stop cam, the tension releasing lever0 linkedto the clutch levermovesinthe
direction of the arrow.
The end of the tension releasing rod 0 is fixed to the tension releasing rod support 0 and transmits the
movement to the scissors push lever 0 through the stud screw 0.
The thread take-up leverarm 0 isfixed on theend of thescissorspushlevershaft 0, and thescissorspushlever
shaft causes the thread take-up lever link 0 fixed to the thread take-up leverarm 0 to operate.
A back-and-forth motion is transmitted to the main tension releasingplate 0 fixed on the top of the tension
releasing lever link 0, and at the sametimethe main tension ® is released, the tension disc split tongue 0
attached to the end of thread take-up lever link 0 releases the tension disc ©.
4.
6.
-10-
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DISASSEMBLY PROCEDURES |
[0 Covers
1. Remove the belt cover O-
2. Remove the screw o and the bearing cover
and remove the handle lever O and the handle
clutch spring 0 together.
3. Remove the three screwsO and the cam cover
0.
When one of these three screws is removed it will
allow the feed regulating cover 0 to be removed,
in this case, after removing the cam cover
0,
reattach the handle 0 and the handle clutch
spring 0.
4. Remove the eight screws0 and the top cover 0.
5. Remove the four screws0 and the faceplate 0.
6. Remove the three screws0 and the back panel
cover F 0.
7. Remove the six screws 0 and the back panel
cover R0.
8. Lay the machine down to the left.
9. Loosen the screw 0, and remove therotaryhook
cover 0 as a set.
10. Removethe screw0 and the washer 0, and then
remove the inside rotary hook cover 0.
0
-11 -
0
&
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Ul Lower thread cutter
©
1. Remove the stud screw O.
2. Lower the machine below the bed.
3. Loosen the screw O pull out the cam shaft O, and then remove the lower thread cutter cam O ^nd the
lower thread cutter link 0 as a set.
4. Loosenthe screw O, lowerthe lowerthread cutter lever O, and pull out the lowerthread cutter leverpin 0.
5. Loosen the bolt 0 and the set collar screw and while pulling out the lower thread cutterlever 0, remove the
lower thread cam lever the lower thread cam lever spring
0, and the set collar 0.
H] Presser
1. Remove the screw 0 and the needle 0
2. Remove the screw 0 and the cutter 0.
3. Remove the two screws 0 and the upper thread
cutter lever B 0.
4. Remove the presser adjusting screw 0.
5. Remove the two screws 0 and the presser guide
plate
0.
6. Loosen the screw 0.
7. Loosen the screw 0 on the presser roller unit 0.
8. Whilepullingout the presser bar 0 and the presser
spring 0 from the top of the arm, remove the
presser roller unit
0.
I 0 II
Y r 1
@^ ^
\—0
-—©
0-\ f
0—\\l 0
0—
1
1
j
-0
-0
0^
-12-
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10.
II.
Remove the presser bar lifter connecting rod
spring 0.
Remove the E stop ring0 and the washer 0 ,and
then remove the presser connecting rod 0.
Remove the two screws 0 and the wick base A
12. Remove the two screws0 and the wick base B 0.
13. Loosen the bolt 0, and while pulling out the
lifting lever 0, remove the lifting lever arm 0.
Ul Rotary hook
1. Lay the machine down on the left side.
2. Remove the two screws O and the rotary hook
position bracket A 0.
3. Remove the two screws O and the rotary hook
position bracket B O.
4. Loosen the two screws 0 and remove the rotary
hook 0.
0
01
-13-
0 O
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U] Upper thread cutter
1. Return the machine to its original position.
2. Remove the scissors operating spring O and the
scissors return spring
O.
3. Remove the two bolts O and the upper thread
cutter lever O-
[U Length feed
1. Remove the two screws and slide the lower feed
arm oforward and remove it.
Q] Clamping foot
1. Loosen the screw O*
2. Loosen the screw O, and while pulling out the
length feed arm shaft O, remove the setcollarO
and the length feed arm 0.
3. Remove the four screws 0 and the base needle
plate 0.
-14-
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H] Cutter safety device
1. Remove the stud screw O and the screw O, and
then remove cutter stop connecting rod O-
2. Loosen the two screws 0, and remove the cutter
stop lever assembly 0.
3. Remove the screw O and the main tension
releasing plate O-
4. Remove the stud screw O and the screw O, and
then remove the tension releaser
5. Remove the stud screw O and thethread take-up
lever 0.
6. Loosen the screw 0 and the thread tension 0.
Ul Clutch and brake
1. Loosen the screw O, and remove theclutchspring
0
2. Remove the brake spring 0.
3. Remove the stud screw 0 on the ball joint 0.
4. Loosen the two screws 0, pull out the clutch lever
shaft 0, and remove the clutch lever assembly 0.
5. Remove the screw 0 and the washer 0, and then
remove the emergency stop lever 0 and the
emergency stop lever spring
0.
6. Loosen the bolt 0, and remove the belt shift drive
lever
0.
7. Remove the stop lever0 and the stop leverspring
0 together.
- 15 -
0
0
00 O
0 0
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8. Loosen the nut and turn the thread cutter
connecting rod 0 and remove it.
9. Loosen the screw
0, and while pulling off the
scissors push lever assembly 0, remove the thread
take-up leverarm 0.
113 Feed
1. Loosen the screw O.
2. Remove the stud screw O, and remove the feed
reverse lever O and the feed connecting rod O
together. Becareful not to drop the rolleron the end
of the feed reverse lever.
3. Remove the brake wire o and the brake wire pull
spring 0 together.
4. Remove the screw O (left-hand thread) and the
washer O, and then remove the feed cam 0.
[IT] Needle bar
1. Loosen the needle bar clamp screw 0.
2. Remove the oil cap 0, and then loosen the screw
0 and remove the needle bar supporter guide 0.
3. Removethe oilcap 0, and then pullout the needle
bar 0 and remove the needle bar supporter 0.
4. Slant the needlebar supporter 0, and then pull out
the needle bar 0 and remove the needle bar
supporter 0.
5. Remove theslideblock0 and the needle barclmap
0
6. Remove the oil cap 0, and then loosen the two
screws 0 and removethe needle bar crank 0 with
the needle crank rod 0 attached to it.
7. Loosen the screws 0, and remove the thread take-
up leverstud 0 and the needle thread take-up 0.
-16-
0
0
--"m
f
0
0 0-®--
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[H] Cam relay
1. Remove the change gear L O the change gear
R O
2. Loosen the set collar O screw O and the collar0
screw 0.
3. Whilepulling out the worm wheelshaft 0, remove
the set collar 0 and the collar 0.
4. Loosen the two screws 0, remove the free wheel
gear 0, and pullout the change gearshaft 0.
[m Upper shaft
1. Remove the screw 0.
2. Loosen the screw 0, and pull off the thread take-
up crank 0.
3. Loosen the nut 0 (left-hand thread), turn the idler
pulleyarm 0, and loosenthe tensionof the timing
belt.
4. Loosen the two screws 0 on the worm 0.
5. Loosen the two screws 0 on the reductiongear 0.
6. Loosen the screws and while pulling out the
upper shaft 0, remove the worm 0 and the
reduction gear 0.
17-
0
0
0
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ini Auxiliary shaft
1. Remove the oil cap O.
2. Loosen the screw e ,and remove thecutterdriving
lever shaft O.
3. Loosen the two screws o on the cutter eccentric
wheel O-
4. Loosenthe two screws O on the subshaft gear O.
5. Loosenthetwo screws O on the needlezigzagcam
o
6. Loosen the two screwsO on the set collar 0.
7. While pulling out the sub shaft remove the
cutter eccentric wheel O with the cutter driving
lever 0 asaset,and then remove theauxiliaryshaft
gear O and the needle zigzagcam O-
mi Needle zigzag
1. Removethe oilcap 0> and the loosenthe screwO
on the needle zigzag lever R and the pull out the
needle zigzag F assembly O-
2. Remove the needle zigzag spring A O-
3. Remove the needle zigzag spring B 0.
4. Loosen the screw 0 on the reference arm shaft A
0 and thescrew0 onthe referencearm shaft B 0.
5. Loosen the screw o on the set collar 0, and then
slightly pull out the reference arm shaft A 0
toward the surface plate and remove the stop ring
6. Loosen the screws0 on the set collar 0, and then
slightly pull out the reference arm shaft B 0 and
remove the stop ring 0.
7. Remove the reference arm shaft A 0 and the
referencearm sahft B0 whileturning themtoward
the rear of the arm, and the remove the needle
zigzag 0.
-18-
o
0
0
0
0
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