The key was to use a pulley system that would magnify the applied force.

关键是要使用滑轮系统，以扩大其作用力。

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The pulley over which this rope ran was fastened underneath the lantern in a little iron box, the key to which was kept by the lamp-lighter, and the rope itself was protected by a metal case.

绕绳子的转盘关在灯下面的一只小铁盒里，钥匙由点灯工人保管，绳子在一定的高度内有一根金属管子保护着。

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The key component-tightening pulley of the hand-held binding machine is working under the action of the multi-intersection changing forces.

手持式捆扎机中的张紧轮是在多种交变力的综合作用下进行捆扎工作的关键零件。

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