Hook Protection - DURKOPP ADLER 767 Service Instructions Manual

4.4

Hook protection

4.4.1 Using other needle size
18
1
2
The hook protection 1 avoids a contact between needle and hook tip.
Caution: Danger of injury !
Switch off main switch.
Check and adjust the position of the hook protection only when
the sewing machine is switched off.
Standard checking
In looping stroke position the needle must abut on the hook protection 1
without being displaced.
–
Move needle in looping stroke position by handwheel.
In looping stroke position the hook tip is at the level of the middle of
the needle.
–
Press needle against hook protection 1 manually.
The needle should not touch the hook tip.
Correction
–
Set the hook protection 1 by twisting the screw 2.
ATTENTION !
The position of the hook protection has to be checked and
corrected, if necessary, after the following adjustments:
–
Correction of the needle bar height
–
Correction of the looping stroke
–
Alteration of the needle size by 0.2 mm or more
By use of a needle of different size, please check the following points:
1. When the size difference is at least 0.2 mm.
–
Correct the hook position.
2. When the needle distance between the hollow groove and the
middle of the needle changes.
–
Check the distance between hook and needle.
2 1