Tension Release Lever - Pfaff 3339 Instruction Manual

11.

Tension release lever

21
Requirement
With the bobbin thread released the thread check spring must be at the same height as
the slack thread control wire 4.
Fig. 11 - 26
Turn the V-belt wheel in the direction of rotation until screw 1 is accessible.
Loosen nut 2 and turn screw 1 in accordance with the requirement.
The thread tension should now have a small amount of play, i.e. when pressure is
applied to the tension release lever 3 the thread check spring must go down a little.
Tighten nut 2.
Turn the V-belt wheel a few more rotations in the direction of rotation. The thread
tension must now be fully effective and there must be some play between screw 1 and
lever 3.
Continue turning the V-belt wheel until the machine is in program end position and the
take up lever is at its t.d.c.
Adjustment
2
1
3
4
11 - 27