Sewing machine stitch width control - has a variable pivoting point for lever acting while machine operates or is at rest

摘要

The mechanism to alter the width of stitches on a sewing machine, partic. a buttonhole stitching machine, has a double-armed lever with an adjustable pivoting point between the pin of a swing fork and the swing angled lever. A sliding block and slotted link are used to provide the variable pivoting point for the double-armed lever. A single-arm lever rotates on the slide to act with an adjustable operating cam. The design allows the side swing movement of the needle to be altered continuously while the machine is operating or while it is at rest.