Needle Throwing; Material Feed (Longitudinal); Lateral Feed; Reverse Stitching - ELNA E9020 Service Manual

Needle throwing

The needle throwing motion is controlled by transmitting an angle of rotation of the needle throwing STM shaft to the needle bar frame by way of link. The time to
compensate the origin of STM is when the needle throws to the left stitch base line as long as the power to the machine is ON.
When the STM is turned beyond the right stitch base line, the needle bar disengaging mechanism actuates.
[Performance of the needle throwing STM]

Material feed (longitudinal)

An angle of rotation of the longitudinal feed STM is transmitted to the cloth feed mechanism as an inclination of the feed adjuster shaft by way of a gear so as to cause
the feed mechanism to feed the material according to the feed amount programed for each kind of stitching pattern.
The feed mechanism is controlled also when the sewing machine is turned by hand.
[Performance of the longitudinal fedd STM]

Lateral feed

The machine performs lateral feed of the material by directly transmitting an angle of rotation of the lateral feed STM (commonly works to control thread trimming) to the
feed dog by way of a link.
[Performance of the lateral feed STM]

Reverse stitching

1) Regular patterns (excluding lateral feed straight stitch patterns, zigzag patterns and embroidery patterns)
Turn ON the reverse stitching switch, and the sewing machine rotates at low speed. The longitudinal feed STM moves the feed adjuster to the reverse stitching
position to move the feed backward. Turn OFF the switch, and the machine stops with its needle down.
The feed amount employed in reverse feed stitching for straight stitching is sama as normal feed stitching.
For a pattern other than straight stitch patterns, the reverse feed amount is fixed at -0.5 mm.
2) Lateral feed patterns (lateral feed straight stitch patterns and lateral feed zigzag patterns)
Turn ON the reverse stitching switch, and the sewing machine rotates at low speed. At this time, the longitudinal feed STM moves to the position at which the feed
mount is set to 0 mm. Now, the lateral feed STM actuates to feed the material in the reverse direction.
Main shaft is is
disengaged.
Left stitch base line (origin)
-5 mm
Thread tension release 1
Thread tension
release 2
Knife is disengaged.
Origin
Right stitch
base line
Needle throw
Longitudinal feed
Origin
+5 mm
Right-hand side
of feed dog
Lateral feed
Left-hand side of feed dog
6