Sewing machine stitching mechanism relaxes the pressure on the fabric by the presser foot, when the upper thread is clamped between the needle and thread lever on the first seam stitch, for an extended duration with a thicker fabric

摘要

A sewing machine mechanism to draw the free end (83) of the upper thread (62) through the upper surface of the fabric workpiece (74,75) to the under surface on the first stitch of a stitched seam, has a needle (11) to carry the thread from its bobbin. The looper (12) forms the upper thread loop under the fabric, while the upper thread is clamped between the needle and the upper thread lever (64). At a sewing machine, the mechanism to draw the free end (83) of the upper thread (62) through the upper surface of the fabric workpiece (74,75) to the under surface on the first stitch of a stitched seam, has a needle (11) to carry the thread from its bobbin. The looper (12) forms the upper thread loop under the fabric, while the upper thread is clamped between the needle and the upper thread lever (64). While the upper thread is clamped, the presser foot (25) is at least partially relaxed for a duration which is extended on an increasing fabric thickness (s).