ELNA Supermatic Service Manual page 29

The Thread Release has two stops, the adjustable Guard Ring
Stop and a Stop tab and notch in the frame of the Thread
Release.
The Shuttle Beak attached to the upper and lower guard
rings has two Stop points (shown in RED), one on either side
of the needle.
The Thread Release stops engage with the Shuttle Beak
stops, which prevents the Guard Rings from turning with the
rotating Shuttle Hook.
The Thread Release stops are at different heights, which
alternately engage the Shuttle Beak stops as the Thread
Release pivots up‐and‐down.
The Thread Release begins to rise as the shuttle hook passes
under the Shuttle Beak and approaches the needle,
disengaging the Guard Ring Stop with Shuttle Beak.
The Shuttle Hook is then able to catch the upper thread loop
and pass it under the Guard Ring Stop as it wraps the loop
around the shuttle.
The Stop notch holds back the Shuttle Beak, while the Guard
Ring Stop is situated higher than the Shuttle Beak.
As the Shuttle Hook completes about half a turn, the Thread
Release begins to lower.
As the Shuttle Hook completes about three quarters of a turn, the thread Take‐up Lever pulls the upper thread
loop off the shuttle hook.
The Thread Release descends to engage the Guard Ring Stop with the Shuttle Beak, and drop the notch Stop
below the Shuttle Beak.
The upper thread loop can now pass between the Stop and the Shuttle Beak to exit the shuttle.
Each stitch requires one down and up cycle of the
Needle and Take‐up Lever.
However the Shuttle Hook must make two complete
revolutions and the Thread Release makes two up
and down cycles to complete a stitch.
The first revolution of the Shuttle Hook is to wrap the
upper thread loop around lower bobbin thread.
The second revolution of the Shuttle Hook is to allow
the Take‐up Lever to pull the threads tight to
complete the stitch.
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