Such machinery can realize perfect and stable sewing quality by the low-tension sewing. The connecting bar thread-taking-up, oscillating shuttle thread-hooking and the synchronous feeding of the feed dogs and presser foot can product the lockstitches and bartacking seams. The bartacking patterns are beautiful. The lifting amount of the presser foot can reach 17mm, which facilitates the taking and putting of materials and the smooth sewing of thick materials. They are applicable for the bartacking sewing of medium thick materials. As required by users, 21-stitch, 28-stitch, 36-stitch, 42-stitch bartacking modes can be provided.
