| 摘要 |
PROBLEM TO BE SOLVED: To surely cut a thread by setting a driving amount of an X-Y driving means in such a manner that a cutting objective thread may approach the moving track of a blade part when the blade part of a movable blade and a fixed blade are engaged, based on the size of a needle eye which is selected by a selecting means and final sewing data before the thread cutting or the like. SOLUTION: A DIP switch 52 to select the radius of a needle eye is connected to a CPU 30 through an I/F 50, and by the setting of an on/off state of two switches of the DIP switch 52, the radius R of a needle eye and a spectrum (b) for an optimal thread cutting point from a needle eye center O are selected. At the time of a sewing, an idle feeding amount (c) is obtained by using the radius R and the spectrum (b) selected by the CPU 30. Then, right before a thread cutting, by an idle feeding by the idle feeding amount (c), a cutting objective thread is neared to the optimal thread cutting point (b), i.e., on the moving track of the blade part of a movable blade or its vicinity, and when a fixed blade and the blade part are engaged, the cutting objective thread is located at the approx. center of the blade part, and a thread cutting without an unfavorable cut is made possible.
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