16
3.7 Feeding mechanism of the top roller
3.7.1 Description
The starting movement for the drive of the top roller feeder is
the bottom feeding shaft. From this shaft, the movement is
transmitted by the indented belt (1) onto the top feeding shaft
(2). A component part of the transmission by indented belt is
the pulley (3), the tensioning roller (4), the roller (5) and the
pulley (6). Starting from the shaft (2), the movement is further
transmitted through the friction wheels (7 and 8) of drive con-
version unit onto the articulated shaft (9). From this articulated
shaft, the movement is transmitted by a cone transmission,
situated in the holder (10), onto the feeder wheel (11). The
drive conversion unit serves for compensating the differences
in feeding by the driven top roller and by the lower feed wheeler.
By turning the screw (12), the change of the gear speed ratio is
attained. After having set in accordance with the par. 3.6.6, the
screw (12) in the holder (13) is to be locked by the nut (14).
The pressure of the friction wheels (7 and 8) is ensured by the
compression spring in the shaft (2). To avoid a complete
pushing out from the arm, the shaft is locked by a stirrup ring
(17). The shaft of the friction wheel (8) is mounted in the screw
(12) on needle bearings. The articulated shaft (9) contains two
joints (15) and a telescopic part (16). Both these elements
secure the lifting and the tilting of the top roller.
3.7.2 Feeding clutch
3.7.2.1
Description
The feeding clutch serves for changing the oscillating motion
to the rotary motion of the lower feed shaft. It is formed by the
clutch cover (1) which is locked in the bedplate using the pin
(2), by the clutch star (4) driven by the draw bar (3) from the
feeding mechanism and by the carrier disk (5) which is firmly
connected with the shaft (6). The draw bar (3) imparts the
clutch its oscillating motion.The clutch is being engaged by
means of the wedge (7) on the connecting rod (8) through the
eccentric (9) which is situated on the bottom shaft (10). In the
position, when the wedge is disengaged, the star (4) is pulled
out from its friction engagement with the lining of the carrier
disk (5) by means of an elastic washer (11). The disk lining (5)
is then pushed by the flat profiled spring (12) against the clutch
cover (1). In this position, the shaft (6) does not perform any
movement. In the position, when the wedge is engaged, the
star (4) is pushed against the lining of the disk (5) and, at the
same time, the connection with the clutch cover (1) is
disengaged and the oscillating motion from the connecting
rod (3) is transmitted to the rotating motion of the shaft (6).
During a short moment, when engaging and disengaging with
the carrier disk (5), both the cover (1) and the star (4) are
engaged, namely in the extreme dead centre of the connecting
rod (3). The clutch change over is to be set in tightening or
loosening the nut (13).
3.7.2.2 Setting of the feeding pitch
The lever (1) transmitting the feeding motion by means of the
connecting rod (3) onto the feeding clutch must be set in such
a way, so that, in the bottom dead centre of the needle, the axis
of the star part (2) is in the axis of the screw (4).
Caution! Danger of injury!
Switch off the main switch! Before starting the
setting operation, wait until the motor stops!
Lever (1) displacement
- Loosen the screw (6).
- Set the maximum stitch length.
- Set the angle 180
°
on the handwheel.
- Unscrew the screw (5) and put the needle shank in its hole.
- Turn the lever (1), until the needle fits into the hole in the
star part (2).
- Side set the lever (1) to the measure A= 0.5 to 1 mm.
- Tighten the screw (6).
- Screw in the screw (5) and seal it with the Loctite cement.
6
2
5
1
4
3
15
9
16
15
10
11
17
8
13
12
14
7
2
5
4
2
5
3
6
1
A
3
9
1
13
7
4
12
5
11
6
10
8
2