PURPOSE: To automatically correct sewing errors, when a difference in level on cloth to be sewn is detected near the needle location of a sewing machine by correcting the number of stitch counted by a counter to a prescribed number preliminarily set for the position of the difference in level.
CONSTITUTION: In an industrial sewing machine for manufacturing cloth-made athletic shoes, if a cloth to be sewn is so thick that the presser foot at the lower end of a holding bar 34 is positioned upward, a stepped part sensor 60 is installed in which an optical path is open from a light emitting element to a light receiving element. In addition, the cloth is divided into plural sewing areas, and sewing is performed while counting the number of stitch in accordance with a sewing data in which the number of stitch and sewing conditions are set for each section with different sewing conditions in each area. In this case, the stepped part sensor 60 discriminates the presence or absence of a difference in level on the cloth; in the case of the presence, the sewing of an area O is assumed to be complete, the sewing data is renewed with those for the sewing of an area 1, the count of the number of stitch is also initialized, and the sewing is commenced for the next sewing area 1.
ASAI SHIN
AKAHA KOICHI
OTSUKA YOSHIYUKI
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