rotary hook
大钩；
旋转式梭仔；
旋转钩
The ideal lower tension can now be achieved as a result of improvements in thethread take -up ,rotary hook and feed mechanisms.
通过对挑线杆旋梭送料机构的合理改良,可在降低张力的条件下获得理想满意的缝纫效果.
手机提问的朋友在客户端右上角评价点【满意】即可.