Class 272/274: Synchronisation Of Needle Feed And Underfeed - Duerkopp Adler 271 Service Manual

2.4 Class 272/274: synchronisation of needle feed and underfeed

1 2
1
12
3
Regulation and inspection
The needle feed and underfeed are factory-set to be equal.
–
Set stitch length to maximum.
–
Check synchronisation by turning the handwheel.
Caution: danger of injury
Turn off the main switch.
The needle feed and underfeed may only be adjusted with the sewing
machine switched off.
Adjustment
–
Remove bobbin-winder cover.
–
Check that groove 4 of shaft 1 and slit 2 of block 3 are in line.
If not, turn shaft 1 until they are.
–
Undo locking screw 8.
–
Turn eccentric bolt 6.
Groove 5 and slit 7 must be in the position shown in the illustration.
The synchronisation of needle feed and underfeed is set.
–
Retighten locking screw 8.
With feed-critical material, in order to reduce any displacement of the
fabric layers which may occur, the needle feed can be set up to some
15% greater than the underfeed by turning eccentric bolt 6.
Turning it by 180° produces the maximum adjustment.
The distance between the needle bar and pressure bar remains at
9 mm during this adjustment.
6
If the eccentric bolt is adjusted by less than this, the distance between
8
the needle bar and pressure bar must be re-adjusted.
IMPORTANT
When the needle feed is increased the needle must not touch the
sides of the needle hole in the feed dog.
4
5 6 7 8