The working principle is similar to that of the ordinary hydraulic cylinder, with a manual jack, Jack is also the simplest oil cylinder.

工作原理与普通的液压油缸基本相似，拿一个手动千斤顶来说，千斤顶其实也就是个最简单的油缸了。

youdao

Traditional method for overhaul of the top of miter gate is through manual operation by hydraulic hoisting jack which has the shortcomings of low efficiency and great risk.

摘要船闸人字门顶门检修的传统方法是采用液压千斤顶手动作业，工作效率低，时间长，技术风险大。

youdao

On the manual warning button has the fire prevention telephone jack.

手动报警按钮上带有消防电话插孔。

youdao