22
5
1
4
3
2
7
8
9
A
B
1
6
5
2
4
5
3
2
1
A
3.8 Setting the presser foot lift
The maximum lift of the presser foot when lifting the foot with
knee lever or with electromagnet is to be A = 12.5 mm.
Caution! Danger of injury!
Switch off the main switch! Before starting the
setting operation, wait until the motor stops!
- Place a cube (1) having the height of A = 12.5 ± 0.7 mm
under the presser foot.
- Screw in thoroughly downwards the screw (2).
- Tighten slightly the screw (3) in such a way that the lever (4)
turns on the shaft (5) with a certain friction moment.
- Push with the screwdriver on the lever (4), until it attains the
wall inside the arm of the sewing machine. In this position,
tighten duly the screw (3).
- Check the axial clearance of the shaft (5) which should be
the least possible.
- Set the normal pressure force of the presser foot.
3.9 Bobbin winder
3.9.1 Description
The winder (bobbin winder) winds a reserve of the hook thread.
It is driven by a spring-mounted friction gear, which stops after
having filled the bobbin.
An ideal winding is attained with a sufficient pretension of the
thread obtained on the thread guide (4) and with 1 mm under
the diameter of the bobbin. The shaft is mounted in a swinging
way and the friction gear is put into engagement by means of a
pickup lever (1) and a cam. The winder is fixed on the machine
arm by two screws (3). The thread is passed through according
to the illustration, the thread is cut off after having stopped the
winding operation using the cutting device (5).
3.9.2
Setting the bobbin winder stop
The moment of interrupting the winding is determined by the
mutual position of the pickup lever (1) and the cam (5) on a
common shaft. The cam is locked in its functional position by
the screw (6). The mutual position is to be set on a not
incorporated winder in such a way that in the moment, when
the pickup lever leaves the space of the bobbin, the pressing
function of the cam on the winders shaft is interrupted and it
moves in the sense of the arrow. A fine setting is to be done on
an incorporated condition in the machine. Using the screw (2),
the position of the friction part of the pickup lever (1) is adapted.
In opening the lever, the stopping function is accelerated. Its
inverse function delays it. A test is to be done after having
inserted the bobbin, when passing the thread through the device
and when winding at the running of the machine.
3.9.3 Setting the friction gear
The friction gear is formed frontally by the disk (8) on the main
top shaft of the machine and by the disk (7) with a rubber ring
on the shaft of the winder.
Caution! Danger of injury!
Switch off the main switch! Before starting the
setting operation, wait until the motor stops!
- Proceed to the setting operation with a removed rear guard.
- The winder is in its stopped position.
- Loosen two screws (9) in the disk (8) through the hole in the
arm.
- By shifting axially the disk in the sense A, B, set the disks of
the winder (7) at the distance of 0.5 mm from the rubber ring.
- Tighten the screws (9) in the disk (8).
- Put the winder in its working position and proceed to a
winding test.
- Mount the rear guard.
