ELEKTRONISCH GESTEUERTE NAEHMASCHINE

摘要

The sewing machine has a device for forming a stitch (DV) comprising an upper drive shaft turned by a motor (M) of the machine and generating one synchronisation pulse per revolution. A static memory (ROM) stores a certain amount of pattern control data comprising the control data for forming a buttonhole. The static memory is addressed sequentially to extract the data controlling the pattern per revolution of the upper drive shaft. The data will drive the device forming the stitches (DV). A counter adds the synchronisation pulses generated by the device forming the stitches (DV), that is to say the number of stitches to be formed during which a stitch pattern is produced. A memory (L1, L2) stores the number of synchronisation pulses added by the counter (C). Comparison means (COMP1, COMP2) compare the counts of the synchronisation pulses by the counter (C) and the number of stitches stored in memory (L1, L2) in order to cyclically form a buttonhole with a defined number of stitches and a pattern selector (PS) operating selectively in order to address the control data for the buttonhole (I1, I2) stored in the static memory (ROM). <IMAGE>