Duerkopp Adler 743-121 Operating instructions

Contents Page:
Part 3: Service Instructions for the 743-121
1. General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Setting the Machine Head
2.1 Arm Shaft Crank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2 Needle Evasion Movement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.3 Symmetry of Looper Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2.4 Hook at Needle Center . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.5 Needle Bar Height . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.6 Needle Guard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.7 Thread Take-up Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
2.8 Rocker Bolt and Left Lower Shaft Bearing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2.9 Hook Drive Housing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3. Setting the Sewing Unit
3.1 Thread Trimmer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.2 Check Spring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4. Folding Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.1 Folding Table Retraction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.2 Angle Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5. Transport Carriage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.1 Run-off Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.2 Guide Roller for the Configuration Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6. Contact Cylinder for the Configuration Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.1 Locking Movement for the Configuration Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7. Setting the Configuration Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
1

2

1. General
ATTENTION !
The tasks described in the service instructions must only be conducted
by specialized personnel or persons with appropriate training !
Caution Risk of Injury !
Bei Reparatur-, UmFor repair, conversion and maintenance work the
main switch must be turned off and the sewing unit disconnected from
the pneumatic air supply.
Adjustment work and function testing on a machine under power must
only be conducted with strict adherence to the safety measures and
extreme caution.
The machine head is equipped with adjustment aids which make it
possible to adjust the machine quickly and easily.
With the adjustment pin 1(in the accessories package) and an
adjustment ring 3 attached to the pulley on the arm shaft the sewing
unit can be arrested in 4 adjustment positions.
Dependent on the selected position, 2 to 5 grooves are visible on the
adjustment pin 1 (2 = housing wall).
The positions A, B, Cand Dstamped into the handwheel for ease of
location. The marking on the covering hood serves as an indicator.
A = 2 grooves visible
B = 3 grooves visible
C = 4 grooves visible
D = 5 grooves visible
3

2. Setting the Machine Head
2.1 Arm shaft crank
The tracing groove of the arm shaft crank and the slot Aof the
adjustment ring must be in-line.
Caution Risk of Injury !
Turn main switch off before adjusting.
–Push the second adjustment pin 1 into the tracing hole and allow
the arm shaft crank tracing groove to lock on.
A pen or a 5 mm drill bit can also be used instead of the second
adjustment pin.
–Check to see if in this position the adjustment pin 2 can be inserted
into position A(2 grooves visible).
If not, the arm shaft crank must be adjusted on the arm shaft.
Setting the arm shaft
–Remove the front cover.
–Loosen the arm shaft crank locking screws and adjust the crank
appropriately.
–Tighten the locking screws.
12
4

2.2 Needle Evasion Movement
With needle evasion movement (ellipse width) is meant the movement
which the hook makes in order to pass behind the needle when
moving from right to left and infront of the needle when moving from
left to right.
With this sewing unit the ellipse width should be 1.9 mm.
( Needle thickness Nm 90 )
Caution Risk of Injury !
Turn the main switch off before measuring and adjusting.
Measuring the ellipse width
–Attach the measuring dail 1 with the parts kit 2
(Order no. 935 008021).
–Set the lowest and highest points by turning the handwheel. The
difference should be 1.9 mm.
Setting the ellipse width
–Displace the lower shaft 3 along its axis
To the right: Ellipse width decreases
To the left: Ellipse width increases
–Then set the set collars 4 and 5 at the center bearing tight again.
Check the lower shaft for ease of movement !
1
2
3
4
5
5

2.3 Symmetry of Looper Motion
Looper motion symmetry is set with the gauges 1 and 2
(Order no. 0933 080192).
Caution Risk of Injury !
Turn the main switch off before adjusting.
–Arrest the sewing unit in position A(2 grooves visible).
–Attach angle 1 and pointer 2 (see illustration).
–Loosen the set screws on the lower pulley.
–Check to see if the pointer moves up by turning the lower shaft in
the direction of rotation.
If not, the lower shaft must be turned accordingly.
–Tighten the set screws on the lower pulley.
–Align the pointer to the measuring edge of the angle 2.
–Pull out the adjustment pin and move the sewing unit to position D
(5 grooves visible) by turning the handwheel and arrest there.
The pointer 2 should have made a pendulum movement up and
back to the slit again.
If not, loosen the set screws on the lower pulley.
Reduce the distance between the pointer and the slit by half
through turning the handwheel.
Adjust the angle 1 (measuring edge to pointer).
Repeat the adjustment as often as necessary until the pointer 2
lies exactly on the measuring edge in positions Aand D.
–Withdraw the adjustment pin and move the machine to position A
by turning the handwheel and arrest there.
The pointer 2 should have made a pendulum movement down and
back again to the measuring edge.
This pendulum movement results automatically from the pendulum
movement first set.
1
2
6

2.4 Hook at the Needle Center
In position Cthe hook point should lie at the needle center.
The distance between the hook point and the needle is 0.05...0.1 mm.
Caution Risk of Injury !
Turn off the main switch before adjusting.
–Arrest the sewing unit in position C(4 grooves visible).
–Set the position of the hook with the stop screws 1 and 2.
–Set the distance to the needle by sliding the hook in the axial
direction.
Screw 3 fastens the hook.
1
2
3
7

2.5 Needle Bar Height
The height of the needle bar is correctly set when the hook eye lies at
the center of the needle and the upper edge of the needle eye lies at
the center of the hook eye.
Caution Risk of Injury !
Turn off main switch before adjusting.
–Unscrew front cover.
–Set needle bar height.
–Tighten the needle bar set screw 1.
1
8

2.6 Needle Guard
The needle guard 1 is to prevent a diversion of the needle into the path
of the hook.
Caution Risk of Injury !
Turn main switch off before adjusting.
Preparation
–Remove thread trimmer (see Section 3.1).
The needle guard mounting screws 2 and 3 are more accessable.
1. Setting height
–Slide the needle guard 1 in the piston.
The undersides of the piston and the needle guard should be flush.
2. Setting position
–Align the needle piston to the hook drive housing.
When the hook point moves from right to left and reaches the
needle, the needle should touch the needle guard.
The needle should not be pushed aside by the needle guard when
lowering.
2
3
1
9

2.7 Thread Take-up Disk
The thread take-up disk is to touch and pull back the bobbin thread
when the hook begins its return movement from left to right.
Caution Risk of Injury !
Turn main switch off before adjusting.
–Arrest sewing unit in position B(3 grooves visible).
–Check the distance between the thread take-up disk catch edge
and the support plate. The distance should be 1 mm. The distance
can be checked with the feeler gauge 1
( no. 0933 080200).
–If the distance is incorrect, the thread take-up disk is to be set
accordingly.
Setting the thread take-up disk
ATTENTION !
The thread take-up disk also acts as a set collar for the shaft.
–Completely loosen clamping screw 6.
Loosen clamping screw 8 so far that the thread take-up disk can be
turned by hand.
–If axial play is available, unscrew the gearing cover and set the
thread take-up disk 7 and gear 9 tight.
Hold the dimension 1mm with gauge 1 ! Tighten screws 6 and 8.
Check the thread take-up disk for ease of movement.
–By moving the brackets 4 and 5 set the middle web of the flap 2
centered to the thread take-up disk.
–Press the brackets 4 and 5 apart and screw fast.
The flap 2 must close without play and the spring 3 must lock in
softly.
1
2
3
4
5
6
7
8
9
10
10