Adler 743-221 Service Manual

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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 adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

1.General

This service manual describes the adjustment of the 743-221 model sewing machine in an expedient sequence.

IMPORTANT !

Various adjustments are mutually interdependent.

The adjustment process must therefore be carried out in the 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 sewing machine is re-started following dismantling the 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 adjustment work and function-testing.

Adjustment work on stitch-forming components

For all adjustments of stitch-forming components a flawless new needle must be fitted.

Caution: danger of injury

Before all repair, conversion and maintenance work:

–turn off the main switch

–isolate the sewing machine from the pneumatic supply.

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 carrying out adjustment work and function-testing with the machine running, comply with all safety measures and take the utmost care.

Pedal

–In the sewing programs the sewing machine can be started by inadvertently depressing the pedal.

IMPORTANT !

All colour-marked components are factory-set. These settings should only be altered by specialists.

3

2.Adjusting the upper part of the machine

2.1	Gauges
	1	2	3	4	5

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	align transport carriage, check reference point, guide
			roller and needle centre
3	feeler gauge	0933 080200	check and adjust guide roller
4	gauge	0935 107071	align needle-bar height and shuttle-drive housing
5	sleeve	0935 107090	align residual-thread monitor

4

2.2Description and adjustment of integral adjusting disc

	3	4
1
		A
		B
		E
		C
2		F
		D
3

The sewing machine can be locked in all adjustment positions with 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 the letters 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 locked 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:

Aadjusting disc with respect to the groove in the arm-shaft crank, belt wheel, loop lift, distance of shuttle beak from needle

B- no function -

C2nd needle position (raised thread-lever position)

D- no function -

Eneedle-bar height

F- no function -

5

2.3Arm-shaft crank

1
2
3	Y

4

X

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 shaft with a locking pin or a 5 mm Ø pin in the arm-shaft groove 4 (through hole 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 switch.

The position of the arm shaft may only be adjusted with the sewing machine switched 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 screw of cogged-belt pulley 6.

–Insert a 5 mm-thick pin into the rig hole 3 and allow it to engage in the arm-shaft groove 4 by turning the handwheel.

–Retighten the screws on the cogged-belt pulley 6. The cogged-belt pulley must not be axially shifted.

5 6

6

2.4Upper-thread tensioner release

1

2

3

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.

–Turn 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 switch.

The upper-thread tensioner release may only be adjusted with the motor-protection switch turned off.

Adjustment

–Slightly undo screw 3.

–Move cylinder 2.

With the upper-thread tensioner open there should be a distance of 1 mm between the tension discs 1.

The distance can be checked with a gauge (see section 2.1 no. 3).

–Retighten screw 3.

7

2.5Thread take-up spring

3

1

2

4

5

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 switch.

The thread take-up spring may only be adjusted with the sewing machine switched off.

Adjusting the spring travel

							–	Undo screw 4.
							–	Rotate bush 3.
								The spring 1 must pre-tension the upper thread at least until the tip
								of the needle penetrates the material.
							–	Retighten screw 4.
							Adjusting the spring tension
							–	Undo screw 5.
	20...30 cN
							–	Adjust the tension by rotating tension bolt 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).
	6							The tension is measured at thread guide 6.
								The thread is drawn parallel to the arm shaft.
							–	Retighten screw 5.

8

2.6Needle-bar height

1

2

3

4

5

Regulation and inspection

Adjustment and inspection are carried out with gauge 1.

Caution: danger of injury

Turn off the main switch.

The needle-bar height may only be adjusted with the sewing machine switched off.

Adjustment

–Remove shaping module 2.

–Remove casing 4.

–Undo light barrier 5 and thread clipper 3 and lay them on the oil reservoir.

–Undo screws 6 on the slide plate and remove the slide plate.

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 slide plate and thread clipper.

6	7	7		6	6

6

6

6

6

9

8

1

9

–Place gauge 1 on the base plate.

–Unscrew safety shutter and head cover.

–Undo clamping screw 9.

–Lock the sewing machine in position E.

–Lower the needle bar 8 onto the gauge 1.

The pin of gauge 1 must fully penetrate the needle bar.

–Tighten needle-bar attachment screw 10.

10	The needle-attachment screw 10 must be aligned in parallel to the
	arm shaft and point to the rear (towards the handwheel).
–	Replace all the parts which have been removed.
	IMPORTANT !
	When fitting the thread clipper place both shims between the
	thread clipper and slide plate.

10

2.7Shuttle settings

2.7.1Loop lift and distance between shuttle beak and needle

0,1 mm

2

3

1

4

Regulation and inspection

The loop lift is the travel of the needle bar from bottom dead centre 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 beak 1 must be at the centre of the needle.

The distance between the shuttle beak 1 and the needle must be 0.1 mm.

Caution: danger of injury

Turn off the main switch.

The loop lift and the distance between the shuttle beak and needle may only be adjusted with the sewing machine switched off.

Adjustment

–Remove shaping module and slide plate (see section 2.6). Fit new needle.

–Undo first attachment screw 3 of shuttle 4.

–Lock sewing machine in position A.

–Undo second attachment screw 3 of shuttle 4.

–Place shuttle beak 1 at centre of needle.

The distance between the shuttle beak 1 and the furrow of the needle must be 0.1 mm.

In this position there is a distance of about 0.4 mm between the shuttle 4 and the bush 2.

If the distance of 0.4 mm is not achieved, the shuttle-drive housing should be adjusted accordingly (see section 7.2).

–Retighten 2 attachment screws 3 of the shuttle 4.

–Replace all the parts which have been removed.

11

2.7.2Shuttle-drive housing

1

2

3

3,8 mm

Regulation and inspection

The shuttle-drive housing 4 is factory-aligned.

It may only be altered in exceptional circumstances.

With the shuttle-drive housing correctly aligned there must be a distance of 0.4 mm between the shuttle and the adjusting ring (see section 2.7.1).

The distance between the slide-plate surface and the thread-drawing plate 3 is 3.8 mm.

Caution: danger of injury

Turn off the main switch.

The shuttle-drive housing 4 may only be adjusted with the sewing machine switched off.

Adjustment

–Remove the shaping module and slide plate (see section 2.6).

–Unscrew locking screw 5.

Beneath the locking screw there is a stop screw.

–Adjust stop screw.

The distance between the slide-plate surface and the thread-drawing plate 3 is 3.8 mm

The distance is checked with gauge 1.

–Retighten locking screw 5.

–Undo screws 2 of the shuttle-drive housing.

–Move shuttle-drive housing 4.

There must be a distance of 0.4 mm between the shuttle and the adjusting ring (see section 2.7.1).

4

5

– 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).

12