Zeroing The Differential Feed (Front Feed Dog) On The Pfaff 939 U - Pfaff 939 U Instruction Manual

12 Zeroing the differential feed (front feed dog)
.05.21
Requirement
With the stitch length set at "0" and the adjustment wheels set at "0", when the balance
wheel is turned, there should be no feeding motion of the differential feed dog.
3
Fig. 12 - 22
● Set the stitch length at "0".
● Set both adjustment wheels 1 at "0".
● Fit the open-ended spanner (width 27) to the torsion-spring collar 2 and use it to hold
regulating shaft 3.
● Loosen screw 4.
● While constantly turning the balance wheel, adjust the spanner on the torsion-spring
collar 2 in accordance with the requirement.
● In this position, move adjustment crank 5 and crank 6 against the cast iron frame and
tighten screw 4.
● Carry out a control in accordance with the requirement.
1
2
on the PFAFF 939 U
5 4
Adjustment
7
112-039
6
12 - 23