Principle of sewing machine without bottom thread

hello, what is the principle of sewing machine without bottom thread? The principle of sewing machine without bottom thread is coil sewing system. Coil sewing system is the core of the working principle of sewing machine without bottom thread. Although the automatic sewing of sewing machine without bottom thread is very simple, it needs the cooperation of gears, pulleys and motors to ensure the work, and its design principle is still very fine. And its sewing method is quite different from manual sewing. Different from the traditional manual sewing, the sewing machine passes through the clothes when working, and the eye of the needle is not at the tail of the needle but behind the tip. The needle is fixed on the needle bar, and the gear and cam move up and down to pull the needle bar to work. And it pulls out a small coil, and the fixing device under the clothes will wrap another thread with this coil, thus achieving the effect of series connection. In this way, it can be sewn continuously, which is very labor-saving.