Stitch Forming Parts - Pfaff expression 2014 Service Manual

Stitch forming parts (Hook)
Foreword:
The sewing hook adjustment consists basically of the three following adjustments:
Needle rise
Needle bar height
Hook-to-needle clearance
Needle rise:
The needle rise is the movement by which the needle must rise from its lowest position until a thread loop
has formed on the side of the needle on which the scarf is located.
When the machine moves further, the looper point must enter the thread loop, widen it and guide it
around the bobbin.
Needle bar height:
The needle bar height must be set in such a way that the sewing hook point can easily enter the thread
loop above the needle eye at straight stitch and zigzag stitch settings.
Hook-to-needle clearance:
The distance of the sewing hook point from the needle must be as small as possible, so that the sewing
hook point does not miss the thread loop.
The sequence of sewing hook adjustments is as follows:
1. Hook-to-needle clearance
2. Bevel gear setting
3. Needle rise
4. Needle bar height
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