SINGER 1375A3 User Manual
Page 11
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them has different functions. The thread tension disc No.4 must be opened to let the
thread pass smoothly in sewing. Especially in sewing die first stitch, stitches skipping
is easy to happen because the thread can not pass due to the j&iction drag. The diread
tension disc should be closed as soon as possible to prevent the end of the thread from
being pulled out of the needle when the button clamp begins to lift at the end of cycle.
The thread tension disc No.2 has the function just contrary. It holds the thread in
sewing. And it will not hold the thread and control the amount of thread that is pulled
through the disc at the end of a sewing cycle to provide sufficient thread for the first
stitch of the following cycle.
The thread tension disc (1) helps the thread tension disc (2) to ensure the capability
of making the seam tight. Although thread tension disc (2) can make thread tight, it is
easy to break thread. The thread tension disc (2) should be as loose as possible. The
thread tension disc (1) will close in sewing to prevent reel thread from being pulled out.
As soon as the thread loop draw-up and the continuous lift of the needle bar pushes the
disc (1) open to release the thread from its spool to compensate the thread which has
been consumed in the sewing material after the formation of the loop and needle bar
lifting to the highest position.
There is a small thread tension disc (6) below the faceplate with only a slight
tension. It reduces the chances of splitting of thread around needlepoint, and keeps the
stability of the formation of thread loop and thread triangle.
To adjust the height of upper thread (5): When the needle bar is at its lowest
position, the thread should be straight, but not too tight. The loop should be stable and
prevent stitch skipping from being twisted when the needle bar moves upward. If
thread twist is so strong that the loop runs away jfrequently. Adjust carefully to reach
the above requirement, as shown in Fig. 14.
n
best little bigger
too small
loop twisted
@a 14 Fig.14