Thread tensioners and limiter. Duerkopp Adler 1140, 1140-5

2

6

8

4

6

8

4

9

5

2

10 8 7

C

A

9

B

4

F

3

7

1

3

7

1

3.4.3 Setting the tensioning mechanism of the main tensioner

The nut (1) must be screwed off in such a way that the metal sheet lever (2) bears on the plate (3) and, at the same time, the lever (4) is not limited by the prop (5) in its rotation. The lever

(4) must be fixed against the shaft (6) in such a way that, when the presser foot is in its lowest position, the nut (1) bears on the metal sheet lever (2) with its minimum clearance.

Caution ! Danger of injury!

Switch off the main switch! Before starting the setting operation, wait until the motor stops!

- Unscrew thoroughly the nut (7) and loosen the screw (8).

- Put in one line the axis of the shaft (6), the axis (9) and the axis of the spherical surface of the nut (1).

- Unscrew the nut (1), until the metal sheet lever (2) strikes against the plate (3). However, the lever (4) must rotate freely in the sense of the arrows in both senses.

- Screw in the nut (7) almost to the stop.

- Remove the sewn material and lower the presser foot.

- Turn the lever (4) in the sense of the arrow up to the stop.

- Return the lever (4) a bit back and tighten the screw (8).

1

2

5

11

1

6

3.4.4 Setting the adapting spring

The mechanism of the adapting spring is to be set up in such a way that, when uscrewing the nut (1) up to the stop to the washer (2), the conical spring (3) remains under the tension which is set by shifting the adjusting ring (4) locked by the screw (1O).

The angular setting thereof is to be done in such a way that the angle „A“ = 45

°

. The axial setting is to be done in such a way that the plate (5) and the plate (6) are at the mutual distance equal to the measure „C“= 3 mm.

The washer (7) is to be oriented in such a way that the distance

„B“ = 1 to 1.5 mm. The bushing (8) is to be oriented in such a way that the adapting spring (9) is tensed up by 90

°

from the free state.

Caution! Danger of injury!

Switch off the main switch! Before starting the setting operation, wait until the motor stops!

- Unscrew the nut (1) up to the stop towards the washer (2).

- Loosen the screw (10), push heavily the ring (4) against the washer (2) and tighten the screw (10).

- Mount the mechanism of the adapting spring into the machine in such a way, so that the pieces (5 and 6) are at the distance „C“ = 3 mm, set the angle „A“ = 45

°

and tighten the screw (11).

- Turn the washer with the nose (7) in such a way that the distance „B“ = 3 mm is attained.

- Put the screwdriver into the slit in the bushing (8) and turn it in counterclockwise direction, until the spring (9) touches slightly the nose of the washer (7). Turn then still the bushing

(8) by 1/4 revolution.

- Tighten the nut (1). In this way, the whole mechanism immobilizes.

8

3

1

2

9

8

7

10

6

3

2 1 11

5

3

4

12

11

13

9

3.4.5 Setting the thread limiter

The thread limiter is to be set in such a way that, when sewing and passing the thread through the most distant point of the hook, the spring (2) shifts by about 1/4 to 3/4 length of its total length. This means that the thicker will be the sewn material and the longer will be the stitch length, the more will be the limiter shifted in the sense of the arrow and inversely.

Under standard sewing conditions, the thread limiter is set in its tested positions depending on the sewing category in accordance with the chapter 11.

Caution! Danger of injury!

Switch off the main switch! Before starting the setting operation, wait until the motor stops!

- Tighten the screw (3).

- Set the thread limiter (1) in such a way that the screw (3) is situated above some letter according to the chapter 11.

- Tighten the screw (3).

3.5 Feeding mechanism of the bootom feed and of needle feed

3.5.1 Description

The bottom feed is formed by two independent mechanisms necessary for attaining an elliptical way of the feeder. The feeding mechanism for the horizontal component of the feeder movement is formed by the lever mechanism (1) – the mechanism of the stitch length. This is driven from the main upper shaft through the eccentric with the connecting rod

(2). The feeding movement is then transmitted by means of the draw bar (3)on the oscillating shaft (4) and, through the lever (10), on the feeder carrier (9). The stitch length (the size of the horizontal component of the feeder movement) is to be set using the button (5) through the leverage (6) onto the lever mechanism (1).

The feeding mechanism for the vertical component of the feeder movement is formed by the lifting eccentric (7) on the bottom shaft. The movement is transmitted by the connecting rod (8) onto the feeder carrier (9).

A source of the needle feed motion is also the mechanism (1).

The swinging motion is transmitted by the shaft (11) to the connecting rod (12) and to the needle bar holder (13).