Atlanta 4500A, Техническое руководство и перечень запасных частей

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Technical Manual & Parts Lists
72
h. Looper Thread take-up Bars
Looper thread take-up bars help to avoid material puckering; adjust the looper take-up so that
the bottom of one bar is aligned with the lower side the other two with a little earlier timing, that
way the looper thread
will not be drawn too
much and a favorable
thread tension can be
obtained. The looper
thread take up timing
can be adjusted by
loosening the gear
pulley.
i. Function of the thread take-up tension discs
The take-up thread tension disc functions especially for preventing the stitches from skipping
during reverse stitching and production of chain-off threads.
It is very important to pull in the slack of the needle thread especially when the feed direction
is reversed. If a slackened needle thread remains on the cloth, it may be cut by the returning
needle or it may form an idle loop which results in stitch skipping. Another function of the take-
up thread tension disc is to take in the slack of the needle thread while the needle goes down in
order to prevent the chain-off threads from skipping. The needle thread is entirely free from the
resistance of the cloth when the chain-off threads are formed. Therefore, when the needle point
comes down to pass through a triangular loop formed on the back of the looper, the triangular
loop will be deformed or broken to skip a stitch of the interloping needle thread is slackened.
j. Relation thread take-up tension plate / take-up thread tension disc.
In order for these two thread components to properly function, it is necessary to maintain the
tension. The standard ratio is 3 g: 1 g (drawing force required for the cotton thread No.60).