Control means for buttonhole zigzag sewing machine

Claim 1

In a zigzag sewing machine including means to oscillate the needle at right angle to the work feeding direction, first control means to vary the overstitch width, second control means to vary the stitching direction, third control means to vary needle stitching position, and manual control means of the sewing of buttonholes comprising: 1. cam means driven by the main drive shaft of the sewing machine, 2. cooperating follower means operably connecting said cam means to said means to oscillate the needle, 3. first, second and third control cam means integral with one another and manipulative by said manual control means, 4. cooperating first, second and third cam follower means operably connecting said control cam means with said first, second and third control means respectively, said control cam means having respectively a series of successive cam tracks designed to have said corresponding control means to be moved to and maintained at working positions such as to effect the sewing of first buttonhole side stitches in a first direction, of first buttonhole barring stitches and second buttonhole side stitches in an opposite direction, and of second buttonhole barring stitches, said manual control means being operably connected to said control cam means to have said control cam means actuated together so as to engage with cooperating follower means at corresponding tracks of said control cam means.