jackscrew meaning in English

【机械工程】螺旋起重器。

13a , ; rectangular connectors for frequencies below 3 mhz ; part 7 : detail specification for a range of connectors with polarized guides or jackscrews and size 16 round contacts ; removable crimp contact types with closed crimp barrels , rear insertion front release , with assessed quality
频率低于3mhz的矩形连接器.第7部分:一系列矩形连接器的详细规范:具有评定标明极性式插孔,螺纹尺寸为16