Abstract: Stitches have once been formed in a sewing machine in four steps to produce a buttonhole, the number of the stitches to be used in each of the steps are stored in a memory, and the stitches in each step are formed with the number of stored stitches for following buttonhole such that all sizes of the buttonholes are made of the same size. The sewing machine is provided with a central circuit which includes a pattern selecting device which selects a cam from a plurality of pattern cams in correspondence to stitching of the designated step in producing the buttonholes. An electronic control device provided in the sewing machine stores the number of stitches formed in accordance with each of the steps with the memory designation, and a stitching mode check device designates a subsequent step in each of the steps. An indicating device provided in the central circuit indicates this designation, and the buttonhole is repeatedly formed.

Abstract: An electronically controlled sewing machine to produce stitches and to change the relative position between the needle and the fabric to be sewn. The sewing machine comprises a first memory (ROM1) storing pattern data including the data for producing straight stitches, pattern selecting means selectively operated to select a set of pattern data of such data stored in the first memory and a second memory (ROM2) storing automatic setting information each specific to the selected pattern and controlling commonly the stitches of the selected pattern. An operator control means adjusts the control of the automatic setting information with respect to the stitches of the selected pattern and a calculating means receives the output of at least one of the second memory (ROM2) and the operator controlled means (VR1, VR2) to calculate the stitch coordinate to each of the stitches of the selected pattern.