DURKOPP ADLER 969 Classic, Service Instructions Manual

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Position of the hook and needle
Service Instructions 969 - 06.0 - 03/2019 51
10 Position of the hook and needle
10.1 Tensioning the hook drive toothed belt
A special measurement tool is required to achieve the proper setting.
Follow the information below when setting the belt tension:
• if the tension is too high, the service life of the toothed belt and ball
bearings is reduced
• if the tension is too low, the toothed belt may slip off the pulleys
Proper setting
When you press down on the toothed belt approximately in the center
between the pulleys with a force of
10 N in the direction of the arrow,
the belt should deflect about 3 mm .
Cover
• Belt cover ( 
p. 17
)
• Tilt the machine head ( 
p. 14
)
Fig. 36: Tensioning the hook drive toothed belt
To tension the hook drive toothed belt:
1. Loosen the screw (3).
2. Turn the eccentric pin (1) with the tensioning pulley and tension the
toothed belt (2).
3. Tighten the screw (3).
CAUTION
Risk of injury from sharp and moving parts!
Puncture and crushing possible.
Switch off the machine before you check and set
the position of the hook and needle.
(1) - Eccentric pin
(2) - Toothed belt
(3) - Screw
①
②
③