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AssigneeShenkar College of Engineering and Design
InventorsAmotz Weinberg, Yair Eilam
Estimating the term…
The present invention relates to the joining of fabrics made of advanced fibers for making preforms for composite materials. More particularly, the invention provides a sewing mechanism which is useful for joining fabrics with a brittle thread. The invention provides a sewing mechanism having a needle for stitching a brittle fiber thread through at least one layer of a fibrous fabric, the mechanisms for supplying the sewing thread to the needle on each edge thereof while the needle penetrates the layer or layers of fibrous fabric, thread supply being controlled to equalize the supply on both sides of the needle to prevent axial movement of the thread relative to the needle while the needle moves downwards. The mechanism further supporting a revolving spool of a second thread and arranged to insert the second thread through a loop formed by the sewing thread at the remote side of the layer of fibrous fabric.
A sewing mechanism supplying sewing thread under controlled tension to the sewing needle from both sides of the said needle in a manner that prevents axial movement of the said thread relative to the said needle while the said needle is moving from one side of the fabric to the other side of the fabric, said needle having an open eye proximate to the needle point for receipt and release of said thread.
A sewing machine having a first vertical axis needle for stitching a brittle fiber thread through at least one layer of an advanced fiber fabric said first needle having an open eye proximate to the needle point for receipt and release of said brittle fiber thread, said machine having mechanisms for supplying said fiber thread to said needle on each edge thereof while said first needle penetrates said layer of advanced fiber fabric, thread supply being controlled to equalize the supply on both sides of said first needle to prevent axial movement relative to said needle of said fiber thread during downward movement of said first needle, said machine being further equipped with a third mechanisms disposed above said fabric, said third mechanism including a second needle disposed at an angle of 60°-120° to said first needle and being axially driven to pierce said fabric and to insert a loop of a second thread through said loop formed by said brittle fiber thread at the lower side of said layer of advanced fiber fabric, and to retract to a position above the upper surface of said fabric before said fabric is moved to the following stitching station.
Dependencies are inferred from the claim text.