Setting The Looper-To-Needle Clearance - Pfaff Coverlock 4772 Service Manual

21. Setting the looper-to-needle clearance

Requirement:
The looper point must touch the scarf of the needle (D) while moving to the front (fig. 37).
When at the rear there should be a clearance of 0.05 - 0.1 mm.
Check:
G Turn the handwheel in the normal direction until the looper point is exactly in the scarf
of the needle (D) while moving to the left.
G The looper point must rest slightly in the scarf of the needle (D)
Setting:
G Turn the handwheel in the normal direction until the looper point of the two thread
chainstitch looper 16, while moving to the left, is exactly in the scarf of the needle (D).
G Slightly loosen the screw 19 on the looper lever (figure 38).
G Set the looper-to-needle clearance by pushing the looper lever.
G Tighten the screw 19 on the looper lever.
Test:
G As described under "Requirement".
G The lateral clearance of the two thread chainstitch looper to the needle must be checked or reset
as described in section 20 in the adjustment and repair instructions after having set the looper-
to-needle clearance.
Note:
The needle will be slightly depressed when it picks up the looper thread.
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