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18. Taking up the teeth clearance of the worm gearing (Fig. 19)
Caution! Danger of injury!
Switch off the main switch! Before starting the setting operation, wait
until the motor stops!
For taking up the teeth clearance of the worm gearing there serves the conic worm
(3). If we want to tak up this clearance, we must remove first the upper guard (1)
after having unscrewed four fastening screws (6). After having loosened the screws
(7) on the adjusting ring (8) and after having loosened four screws (2) on the
worm (3), we can adjust the teeth clearance between the worm and the worm
wheel. When shifting the conic worm towards the mechanism of the take-up lever
we increase the teeth clearance, in the direction towards the handwheel, we reduce
it. This clearance can be well checked on the perimeter of the cam. Secure the
position of the worm with the screws (2). Approach the carrier ring (8) up to the
stop towards the worm and secure it with the screws (7).
19. Setting of the needlebar holder sliding (Fig.19)
Caution! Danger of injury!
Switch off the main switch! Before starting the setting operation, wait until the motor stops!
The needlebar holder may only be slid when the needle is above the material being fed. This condition is to be attained in matching the movement
of the needlebar holder with the cam and the worm. This setting is to be done with any profiled cam mounted. Remove the top guard (1), loosen four
screws (2) of the worm wheel (3). (The carrier ring (8) secures the axial position of the worm and, at the same time, the teeth clearance as well).
In turning the worm on the upper shaft (4) we shall find its optimum position in such a way, so that the holder slides only at the moment, when the
needle is above the sewn material. Tighten the screws of the worm and mount the top guard.
20. Replacement of the profiled cam (Fig. 18)
Caution! Danger of injury!
Switch off the main switch! Before starting the setting operation, wait until the motor stops!
On the machine, there has been mounted in the manufacturing factory a cam for stitching with plain stitch. When replacing the cam using a cam for
stitching another pattern, proceed as follows : Unscrew the nut with the washer and remove the cam (on the back side of the arm). Mount the new
cam on the shaft with an arresting pin and mind the roller fitting into the cam groove. Secure the cam with a nut and a washer.
Caution!
With any cam replacement, be sure in checking the needle to avoid its striking into the presserfoot or throat plate. In the event of such collision, set
the position of the needle (the position of the needlebar holder) with regard to the needle hole in the throat plate according to the par. 16 or set the
width of the pattern according to the par. 6.7, part A.
21. Setting of the needle bar and of the hook shaft position (Fig. 20, 21)
Caution! Danger of injury!
Switch off the main switch! Before starting the setting operation, wait until the motor stops!
After a larger repair of the machine it is suitable to check up the mutual position of the needle bar in its central position and that of the hook shaft.
The axis of the hook shaft is shifted to the left from the axis of the needle bar. Proceed to the respective setting after having loosened two screws (3),
which secure the clamping joint between the bedplate and the hook gearbox. In its correct position, the hook gearbox is pushed to the riser of the
bed plate and the axis of the hook shaft is parallel with the plane of the bedplate. Secure the box position in tightening both screws (3).
Notice!
In case of dismounting the hook gearbox it is necessary to respect, when remounting it, the parallelism of the axis of the hook shaft with the plane
of the bed plate. This parallelism is measured e.g. by means of two shafts, which we place on the top surface of the bedplate and on the machined
surface of the gearbox. We check up this parallelism in measuring the value (B).
6
Fig. 20
7
5
8
1
3
2
7
4
2
Fig. 19
3
Fig. 21
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