| 摘要 |
PROBLEM TO BE SOLVED: To provide vertical rotary shuttle of a sewing machine capable of obtaining a perfect stitch without the twist return of thread and preventing the double pull-up of upper thread by a core point part concerning the performance of a sewing method for parallel sewing by oppositely arranging the two vertical rotary shuttles. SOLUTION: An extending part 209a is arranged in the core point part 209 of a rotating hook 202. Thus, the upper thread 303 is caught from an opposite side when viewing from the side of a rotating hook bobbin case holder 207 by holding the vertical reciprocative movement locus of the needle 102 of the sewing machine between the both sides. A sewing operation is performed in a state where both the two vertical rotary shuttles are in substantially the same state. When shortage in the amount of feeding of the upper thread 303, which is caused with the delay of the thread passage timing of the upper thread 303 by the arrangement of the extending part 209a, is addressed by the increase of a thread pull amount, the upper thread is loosened, so as to generate the double pull-up of the upper thread 303 by the core point part 209. The vertical rotary shuttle includes an upper thread press member (an upper thread press board 245a) for pressurizing the loop of the upper thread 303, which comes to be a thread cast-off space 244 between the core point part 209 and a rotating hook section 242, from the outer peripheral side of the rotating hook 202. Thus, the double pull-up of the upper thread 303 is prevented. COPYRIGHT: (C)2006,JPO&NCIPI
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