Stitch pattern forming control in a sewing machine

摘要

In a sewing machine including a static memory for storing digital information related to the positional coordinates for each stitch of a predetermined stitch pattern, a dynamic memory such as a shift register is provided for temporarily storing the digital information derived from the static memory. Output signals of the dynamic memory are applied to a needle positioning mechanism and a work feed mechanism through driving means. In a preferred form, input means are provided for modifying the digital information temporarily stored in the dynamic memory, thereby modifying the stitch pattern.