DURKOPP ADLER class 743-221, 743-221 Service Manual
Contents Page:
Part 4: Service manual, class 743-221
1. General
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Adjusting the upper part of the machine
2.1 Gauges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Description and adjustment of integral adjusting disc . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Arm-shaft crank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Upper-thread tensioner release . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.5 Thread take-up spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.6 Needle-bar height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.7 Shuttle settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.7.1 Loop lift and distance between shuttle beak and needle . . . . . . . . . . . . . . . . . . . . . . 11
2.7.2 Shuttle-drive housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.8 Bobbin-housing holder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.9 Light barrier of residual-thread monitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
2.10 Bobbin winder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.11 Position sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.12 Replacing the right-hand arm-shaft bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
2.13 Lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.13.1 Shuttle lubrication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
3. Adjusting the sewing machine
3.1 Thread clipper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
3.1.1 Fitting and removing the blades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
3.1.2 Replacing the piston . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
3.2 Folding table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
3.2.1 Retraction of folding table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3.2.2 Angle adjustment, switch point b03 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
3.3 Transport carriage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3.3.1 Overrun protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
3.4 Shaping module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.4.1 Shaping-module guide roller . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
3.4.2 Shaping-module pressure cylinder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
3.4.3 Shaping-module closing movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.4.4 Adjusting the shaping module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4. Maintenance unit
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
5. Maintenance
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
6. Summary of adj u stments
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
1. General
This service manual describes the adjustment of the
743-221
model
sewing machi n e i n an expedient sequen c e.
IMPORTANT !
Various adjustments are mutually interdependent.
The adjustme nt pro c es s m ust therefore be ca r ri ed ou t i n th e order
given.
IMPORTANT !
The activities described in this Service manual may only be carried out
by specialists or by persons with appropriate training.
Danger of breakage
Before the sewi n g mac h i ne is re- started followi ng di sm an tl i n g t he
necessary adjustments must be carried out as specified in this service
manual.
Avoidance of damage to the material clamps:
The sewing machine must never be operated without material. This
also applies to ad j us t me nt wo r k an d f un c ti o n-t es t i ng .
Adjustment work on stitch-forming components
For all adjustments of stit c h-forming components a flawles s n ew
needle must be fi t te d.
Caution: danger of injury
Before all repair, conversion and maintenance work:
–
turn off the main switch
–
isolate the s ew i ng ma c hi n e f rom the pneumatic s up pl y.
Exception:
Adjustment work which is carried out with testing, adjustment or
sewing programs of the control device.
Adjustment work and function-testing with the sewing machine
running
–
When carryin g o ut ad jus t me nt wo r k an d f un c ti o n-t es t ing wi t h t he
machine runni ng , c o mp l y wi t h a l l safety measures a nd ta k e t he
utmost care.
Pedal
–
In the sewing pr o gr a ms the sewing mac hi n e c a n b e s t art ed by
inadvertently depressing the pedal.
IMPORTANT !
All colour-m ar k e d components are f ac t ory - se t. These settings sh ou l d
only be altere d b y s pe c i ali s t s .
3
2. Adjusting the upper part of the machine
2.1 Gauges
With the adjustment gauges listed below the sewing machine can be
precisely adjusted and tested.
item adjustment order no. use
gauge
1
adjusting pin 9301 022608 lock sewing machine in positions A -
F
2
gauge 0935 107077 ali g n t r an s po rt c a r ri ag e, c he c k ref er e nc e po i nt , g ui d e
roller and needle centre
3
feeler gauge 0933 080200 che c k an d a dj u s t g ui d e ro l l er
4
gauge 0935 107071 align needle-bar height and shuttle-drive housing
5
sleeve 0935 107090 ali g n r e s idu al - t hr e ad mo ni t or
12
345
4
2.2 Descripti on and adjustment of integral adjusting disc
The sewing ma chi n e c a n b e l o c k ed i n a ll ad j us t me nt po s i ti o ns w i th
locking pin 3 and the integral adjusting disc 4 on the cogged-belt
pulley of the arm shaft.
The adjusting disc has 6 notches which are marked on the
handwheel 1 by th e l e tt er s A, B, C, D, E and F. In conjunction with
marking 2 the letters indicate the position of the notches in which the
machine can be l o ck ed with pin 3.
Notch A (loop-lift position) is deeper than the other notches.
The following adjustments can be carried out in the various positions:
A
adjusting di sc w i th r es p ect to the groove in the arm-shaft c r a nk,
belt wheel, l oo p l i f t, di s t an c e o f s h ut tl e be ak f r om ne ed l e
B
- no function -
C
2nd needle position (raised thread-lever position)
D
- no function -
E
needle-bar hei g ht
F
- no function -
1
2
3
A
C
E
D
B
3 4
F
5
2.3 Arm-shaft crank
Regulation and inspection
The groove 4 and notch A of the adjusting disc on the cogged-belt
pulley must coincide on the
X - Y
line.
–
Lock the arm sh af t with a locking pi n or a 5 m m Ø p in i n th e
arm-shaft gr oo v e 4 (th r ou gh ho l e 3 ) .
–
It must be possible to pass the locking pin through the hole 2 in
position A into the integral adjusting disc.
IMPORTANT !
Adjustments carried out with the adjusting disc will only be correct if
the disc itself has been adjusted as described below.
If the arm shaft is moved, all subsequent settings must be checked
and adjusted if necessary.
Caution: danger of injury
Turn off the main switc h.
The position o f the arm shaft ma y on l y be ad j us t ed wi t h t he sewing
machine swi tched off.
Adjustment
–
Remove bobbin-winder cover 1.
–
Undo the first screw of the cogged-belt pulley 6 from above with
the Allen key 5 through the hole.
–
Lock cogged-belt pulley in position A with the locking pin.
–
Undo second s cr ew of c og ge d- b el t pu l l ey 6 .
–
Insert a 5 mm-th i c k pi n into the rig hole 3 a nd al l o w it to engage in
the arm-shaft groove 4 by tur ni n g t he ha nd wh ee l .
–
Retighten the screws on the cogged-belt pulley 6.
The cogged-be l t p ul l e y mu st n ot be ax ially shifted.
1
2
3
4
X
Y
5 6
6
2.4 Upper-thread tensi oner release
Regulation and inspection
The cylinder 2 must open the tension discs 1 by about 1 mm.
When closed, the tension discs 1 must keep the upper thread securely
under tension.
–
Tur n the
"program"
switch to 64.
–
Press "STOP" button.
The program is activated.
–
Turn
"program"
switch to 24.
Switch on solenoid valve s24 by pressing the "Σ" button.
The upper-thread tensioner opens.
–
Check distance between tension discs 1.
Caution: danger of injury
Turn off the main switc h.
The upper-thread tensioner release may only be adjusted with the
motor-protection sw i tch tu rne d o ff.
Adjustment
–
Slightly un do screw 3.
–
Move cylinder 2.
With the upper -t hr e ad te ns i o ne r open there should be a distance
of 1 mm between the tension discs 1.
The distance c a n b e c h ec ke d with a gauge (s ee s ect i on 2.1 no. 3).
–
Retighten sc r e w 3 .
1
2
3
7
2.5 Thread take-up spring
Regulation and inspection
The thread take-up spring 1 must keep the upper thread under tension
at least until the tip of the needle has penetrated the material.
Caution: danger of injury
Turn off the main switc h.
The thread take-up spring may only be adjusted with the sewing
machine swi tched off.
Adjusting the spring travel
–
Undo screw 4.
–
Rotate bush 3.
The spring 1 m us t pre-tension the up pe r th r ea d a t l e as t un ti l t he ti p
of the needle penetrates the ma te r i al.
–
Retighten screw 4.
Adjusting the spring tension
–
Undo screw 5.
–
Adjust the te ns i o n b y r ot at i ng te ns i o n b ol t 2.
Depending on the material and thread the tension of the thread
take-up spring must be between 20 and 30 cN (1 cN = 1 g).
The tension is me as u r ed at th read guide 6.
The thread is dr a wn pa r al le l to th e arm shaft.
–
Retighten screw 5.
3
4
5
1
2
20...30 cN
6
8
2.6 Needle-bar hei ght
Regulation and inspection
Adjustment and inspection are carried out with gauge 1.
Caution: danger of injury
Turn off the main switc h.
The needle-bar h ei g ht ma y on l y be adjusted wit h t he s ew i ng ma c hi n e
switched off.
Adjustment
–
Remove shaping module 2.
–
Remove casing 4.
–
Undo light ba r r ier 5 an d t hr e ad c l ipp er 3 an d l a y th em on th e o i l
reservoir.
–
Undo screws 6 on th e s li d e p l at e a nd remove the sli d e p l at e.
IMPORTANT !
The centring screws 7 must not be rotated.
These are used to align the slide plate to the needle.
There are 2 shims between the sl i de pl a te an d t hr e ad c l ipper.
1
2
3
4
5
6 7 7 6 6
6 6 6 6
9
–
Place gauge 1 on th e b as e pl a te .
–
Unscrew safety shutter and head cover.
–
Undo clamping s cr e w 9 .
–
Lock the sewing machine in position E.
–
Lower the needl e ba r 8 o nt o t he ga ug e 1 .
The pin of gauge 1 must fully penetrate the needle bar.
–
Tighten needle-bar attachment screw 10.
The needle-at t a chm ent screw 10 must be aligned in pa ral l e l to th e
arm shaft and po i nt to th e r e ar ( t ow ar d s th e h an dw he el ) .
–
Replace all th e p art s wh i ch h av e be en rem ov e d.
IMPORTANT !
When fitting the thread clipper place both shims between the
thread clipper and slide plate.
10
8
1
9
10
2.7 Shuttle settings
2.7.1 Loop lift and distance between shuttle beak and needle
Regulation and inspection
The loop lift i s t he tr a v el o f t he ne ed l e b ar from bottom dead c en tr e to
the point at which the shuttle beak is at the centre of the needle.
The loop lift is 1.8 mm.
–
Lock the machine in position A.
The shuttle b ea k 1 must be at the ce nt r e o f t he ne ed l e.
The distance b et w e en th e s h ut tl e be ak 1 an d t he ne ed l e m us t be
0.1 mm.
Caution: danger of injury
Turn off the main switc h.
The loop lift and the distance between the shuttle beak and needle
may only be ad jus t ed wi t h the sewing mac hi n e s w i tc h ed off.
Adjustment
–
Remove shaping module and slide plate (see section 2.6).
Fit new needl e.
–
Undo first a tt ac h me nt s c rew 3 of shuttle 4.
–
Lock sewing machine in position A.
–
Undo second a tt ac h me nt screw 3 of shuttle 4.
–
Place shut tle beak 1 at centre of ne ed l e.
The distance b et w e en th e s h ut tl e be ak 1 an d t he fu r row of the
needle must be 0. 1 m m.
In this position there is a distance of about 0.4 mm between the
shuttle 4 and t he bu s h 2 .
If the distanc e of 0. 4 m m i s n ot ac h i ev e d, th e s h ut tl e -dr i ve housing
should be adjusted accordingly (see section 7.2).
–
Retighten 2 at ta c hm en t s cr e ws 3 of th e s h ut tl e 4.
–
Replace all the parts which have been removed.
0,1 mm
1
2
3
4
11
2.7.2 Shuttle-drive housing
Regulation and inspection
The shuttle-drive housing 4 is factory-aligned.
It may only be altered in exceptional circumstances.
With the shut tl e -dr i ve housing corr ectly aligned t he re m us t be a
distance of 0 .4 mm be tween the shuttl e a nd the adjusting ri n g
(see section 2. 7. 1) .
The distance b et w e en th e s l id e- p l at e s u rf a ce a nd the thread-dra wi n g
plate 3 is 3.8 mm.
Caution: danger of injury
Turn off the main switc h.
The shuttle-drive housing 4 may only be adjusted with the sewing
machine swi tched off.
Adjustment
–
Remove the sha pi n g m od ul e an d s l ide plate (see se c ti o n 2 .6 ) .
–
Unscrew locking screw 5.
Beneath the locking screw there is a stop screw.
–
Adjust stop screw.
The distance be tween the slide - pla t e sur f ac e an d t he
thread-drawin g p l at e 3 is 3. 8 m m
The distance is checked with gauge 1.
–
Retighten locking screw 5.
–
Undo screws 2 of the shuttle-drive housing.
–
Move shuttle -dr i ve housing 4.
There must be a distance of 0.4 mm between the shuttle and the
adjusting ring (see section 2.7.1).
–
Retighten screws 2 of the shuttle-drive housing.
–
Check the distance of the shuttle beak to the needle and adjust if
necessary (see section 2.7.1).
3,8 mm
1
2
3
4 5
12
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