Needle Bar Height And Needle Penetration Points; Setting The Needle Bar Height - Pfaff Coverlock 4872 Service Manual

Needle bar height and needle penetration points

1. Setting the needle bar height

Requirement:
The vertical clearance between the overedge needle "R1" and the top edge of the needle plate must be
12 mm when the needle bar 1 is at its upper dead center (fig. 1).
Check:
G Turn the handwheel in the normal direction until the needle bar 1 is at its upper dead center (u.d.c.).
G Insert a new needle Nm 90 into "R1". The needle must be inserted into the needle holder 2 as far as it
will go.
G Check the needle bar height using the adjustment gauge (measurement A).
Setting:
G Remove the face cover.
G Turn the handwheel in the normal direction until the needle bar 1 is at its upper dead center (u.d.c.).
G Slightly loosen the screw 3 of the needle bar connection (fig. 2).
G Move the needle bar 1 upwards without turning it until the needle touches the adjustment gauge (mea-
surement A).
G Tighten the screw 3.
Test:
G Check the clearance.
The needle holder must be parallel to the machine housing.
G The sides of the needles "L0", "L1" and "L2" must not touch the sides of the needle plate (fig. 3).
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