AUTOMATIC THREAD CUTTING DEVICE OF SEWING MACHINE

PROBLEM TO BE SOLVED: To keep the feed performance of a sewing machine with feed teeth by constructing a device so that a slide plate is passed through under the normal path for needle and bobbin threads when moving forward, and the captures the needle and bobbin threads to guide them to the action locus of a movable blade and cut them when moving backward. SOLUTION: In an automatic thread cutting device of sewing machine, a fixed blade 10 is fixed to a thread cutting base plate 9 mounted on a base body 1, and a movable blade 2 and a slide plate 4 are incorporated to form a movable blade unit 40 via a spacer with the same width as the fixed blade 10. The movable blade unit 40 is supported by the thread cutting base plate 9 with the movable blade 2 and fixed blade 10 placed within the movable blade unit so that the movable blade unit can oscillate freely. With a thread cutting drive mechanism of a thread cutting mechanism 32. the slide plate 4 is passed through under the normal path for needle and bobbin threads 36 and 38 when the movable blade unit 40 moves forward, and the slide plate 4 captures the needle and bobbin threads 36 and 38 to guide them to the action locus of the movable blade 2 and cut the needle and bobbin threads 36 and 38 when moving backward.