| 摘要 |
PROBLEM TO BE SOLVED: To surely perform a thread cutting operation even at a part where the exit of a lower thread coming out from a bobbin case corresponds to the left side or lower part of a sewing needle even in when stitches by the entanglement of an upper thread and the lower thread become hitch stitches. SOLUTION: A thread cutting mechanism 12 including a stationary knife 18 and a movable knife 19 capable of turning is arranged under a needle plate 8; a looper 9 is provided right on the lower side of the thread cutting mechanism 12 and is connected to the front end part of a lower shaft. When sewing is started, by the rotation of the lower shaft, the looper 9 is rotationally driven clockwise when it is viewed from the front. When the sewing needle is slightly elevated from the bottom position, the upper thread extending from the eye hole of the sewing needle is hooked to a point portion integrally formed on the outer shuttle of the looper 9 and an upper thread loop 16a is enlarged. When cutting the thread, the apical portion of the movable knife 19 enters the upper thread loop 16a from a direction perpendicular to the loop surface of the upper thread loop 16a to be enlarged. COPYRIGHT: (C)2009,JPO&INPIT
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