This machine adopts double straight needles, vertical automatic refueling shuttle hook line, slide rod take-up line, forming two-line double-line lock type line trace. The upper and lower axles are driven by synchronous toothed belt. The needle rod swing and feeding mode, knob type dial pitch and lever type backward feeding mechanism are adopted. The sewing spring in the shuttle core ensures the same sewing effect between the bottom line and the surface line.
