Setting The Ellipsoidal Movement - Pfaff Coverlock 4872 Service Manual

19. Setting the ellipsoidal movement

Requirement:
When the needle bar is at its lowest position, the two thread chainstitch looper must be at its right point of
reversal, when moving to the right (fig. 33).
Note:
This adjustment must only be carried out if a compelling reason exists.
Check:
G Turn the handwheel in the normal direction until the two thread chainstitch looper is at its right point of
reversal when moving to the right.
G Carry out a visual check.
Setting:
G Insert a new needle in the needle holder "R1".
G Turn the handwheel in the normal direction until the needle is positioned as in fig. 34.
G Slightly loosen the screws 15 on the drive eccentric (fig. 35).
G Move the drive eccentric until the markings 16 and 17 are exactly opposite one another.
G Tighten the screws 15.
Test:
G As described under "Requirement".
Note:
Should the loops of the two thread chainstitch needle not be correctly formed, the drive eccentric must be
moved and set as in fig. 36.
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