| 摘要 |
PURPOSE:To eliminate the need for a thread cutting work operation again by a worker even when a movable blade is stopped before cutting thread by detecting the angle of rotation of an upper shaft when a driving means by a signal from a detecting means is stopped, and operating the driving means again based on the signal. CONSTITUTION:While the movable blade 11 is being turned i.e., the thread 18 is dipped up and is engaged with a fixed blade 12, the thread 18 is stretched between the movable blade 11 and a holding member 17, and at this time, the movable blade 11 is stopped based on the thickness or the tensile force of the thread 18, and a motor 7 is stopped with the detecting means. When the stoppage of the motor 7 is detected, the angle of rotation of the upper shaft 6 of a sewing machine is detected with an encoder 14, and it is compared with the range of the angle of rotation of the upper shaft 6 of the sewing machine stored in a control circuit 13, and it is detected whether or not the movable blade 11 is stopped due to the thickness or the tensile force of the thread. At this time, when the angle of rotation of the upper shaft 6 of the sewing machine is outside the range stored in the control circuit 13, an error is displayed on a display 16, then, the emergency stoppage of the sewing machine 3 is performed. Also, when the angle of rotation of the upper shaft 6 of the sewing machine is within the range stored in the control circuit 13, the motor is operated again, and the thread cutting operation is restarted.
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