4-Thread Safety Stitch, Highly Elastic, Imitated - Silvercrest SON 90 A1 Instrucciones De Uso

4-thread safety stitch, highly elastic, imitated

Figure 75 shows you the stitch pattern for this stitch.
This stitch with 2 needles and 4 threads is ideal for medium to heavy,
stretchy fabrics such as double-knitted materials and swimwear.
It is suitable for combining two materials and neatening the edges at the
same time.
Adjust the thread tension selectors r t z u to the appropriate values
(see table) then sew a test seam on the material being used.
Textiles
blue
2.5
light material
medium-
3.0
weight
material
heavy
4.0
material
Should the upper looper yarn lie on the underside of the textile (Fig. 76):
• turn the thread tension selector for the upper looper thread z (red) to a
higher number, or ...
• turn the thread tension selector for the lower looper thread u (yellow)
to a lower number.
Should the lower looper yarn lie on the upperside of the textile (Fig. 77):
• turn the thread tension selector for the lower looper thread u (yellow) to a
higher number, or ...
• turn the thread tension selector for the upper looper thread z (red) to
a lower number.
Should the left needle yarn be too loose (Fig. 78):
• turn the thread tension selector for the left needle r (blue) to a higher
number.
Should the right needle yarn be too loose (Fig. 79):
• turn the thread tension selector for the right needle t (green) to a higher
number.
Tensioning the thread
green red yellow
2.0 2.5 2.0
2.0 3.0 2.0
2.5 4.0 2.5
Needle position
Seam width switch
Stitch length
Upper looper element
upper looper thread
Right needle thread
Left needle thread
Top
upper looper thread
Right needle thread
Left needle thread
Top
upper looper thread
Right needle thread
Left needle thread
Top
upper looper thread
Right needle thread
Left needle thread
Top
upper looper thread
Right needle thread
Left needle thread
Top
- 135 -
S
2 - 4
not necessary
Correct thread tension
lower looper thread
Underside
Incorrect thread tension
lower looper thread
Underside
lower looper thread
Underside
lower looper thread
Underside
lower looper thread
Underside
Fig. 75
Fig. 76
Fig. 77
Fig. 78
Fig. 79