rotary
问题描述：
rotary
答
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.
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