18
3.6.7 Top roller
3.6.7.1 Selection of the top roller diameter
The machine can be supplied with two types of top roller,
namely with the diameter of 25 mm and with the diameter of
35 mm. The suitability of the diameter used depends on the
type of sewing and on the concrete technological operation.
There are in general valid the following principles for the
selection of the wheel diameter:
ø
25 mm - for sewing small radii
ø
35 mm - for sewing straight sections or big radii
- for sewing with great passages to thicker materials
3.6.9.2 Forward, rearward and side setting
The top roller must be in a defined position in relation to the
needle:
a)view (see Fig. 1) - the value X depends on the diameter of
use top roller (
ø
25 - 6.5 mm;
ø
35 - 10.5 mm), it is measured
from the the needle bar up to the roller edge when turning
the handwheel to the 180
°
of the scale against the indicator
b)view (see Fig. 2) - the wheel edge must fit with the edge of
the needle operture at the spot of the needle punch.
These values are to be set as follows:
Caution! Danger of injury!
Switch off the main switch! Before starting the
setting operation, wait until the motor stops!
- Loosen the screw (1).
- By shifting the holder (2) with the top roller (3) in the groove
of the holder (4) set the required value X and tighten the
screw(1).
- Loosen the screw (5).
- By shifting the holder (2) in the holder (6) set the bottom
edge of the roller to the edge of the needle operture.
- Tighten the screw (5).
3.6.7.3 Setting the gear clearance
and in the mounting of the top roller
In the cone gear of the drive of the top roller foot, the minimum
clearance must be set. A too small clearance will increase the
friction resistance of the gear, the excessive clearance will
influence the inaccuracy of feeding. The top roller itself is
mounted on balls. With this type of mounting,it is also
necessary to set the minimal possible radial clearance.
The given clearances are set as follows:
Caution! Danger of injury!
Switch off the main switch! Before starting the
setting operation, wait until the motor stops!
Clearance in the wheel mounting
- Loosen three screws (5) /only slightly/.
- Using the screw (4) set the minimum clearance in the top
roller mounting (2) /it must easily rotate without any rubbing
and with a minimum clearance/.
- Tighten the screws (5), check the set up clearance, even-
tually, repeat the setting procedure.
Clearance in the conic gear
- Loosen the screw (1), in shifting the wheel, resp. the holder
(3) in the holder groove (6), set the minimum clearance,
the pinion (7) must be pushed up to the holder bottom (6).
- Tighten the screw (1), check the set up clearance.
Fig. 1
X
3
2
6
5
1
4
Fig. 2
4
3
1
2
7
5
6
