Abstract: An apparatus for flicker protection when a servo motor driven sewing machine starts utilizing comparators. Setting the original voltage as the reference voltage and the dropped voltage as the monitor voltage, the comparator compares the voltages and, if the difference exceeded more than the predetermined value, signals for setting the maximum electric current to the servo motor are attenuated such that the voltage drop of the electric source will be reduced.

Abstract: In a sewing machine equipped with an apparatus to terminate stitching at a predetermined point, the machine normally does not terminate stitching exactly at the desired predetermined point because the elastic nature of the workpiece causes the workpiece to stretch. A last stitch is added beyond the point where stitching terminates by the "step sewing" apparatus of this invention. To perform step sewing, an operator inputs a stitch pitch for step sewing with a digital switch, then pushes a step sewing button. Based on the selected stitch pitch, a CPU reads selected stitch pitch data. The data is used by the CPU to control a stitch pitch setting mechanism. A stitching device then performs a single stitch at the selected stitch pitch. By selecting the proper stitch pitch, the last stitch can terminate at the desired termination point.

Abstract: In a seam forming method and device for a sewing machine for embroidery, wherein a contour of a figure to be embroidered is converted into positional co-ordinates and read, data is calculated for alternately setting needle location points on opposing portions of the contour in such a manner that embroidery seams is formed in the contour corresponding to the positional co-ordinates thus read, and the data are read out and a needle is vertically moved to form the embroidery seams, with a taboret being moved in directions X and Y, with a figure including at least one side having a circular arc-shaped contour out of two opposing sides, needle location points are set at regular intervals circumferentially on a circular arc-shaped side, and needle location points on a side opposed to the circular arc-shaped side are set at points of intersections of the side opposed to the circular arc-shaped side with radial lines from the center of the circular arc passing through the midpoint of the needle location points on the