overtravel

This control effect can be got by designing the size of pokedwheel,using the self locking character of worm wheel and worm pole and connecting the pawl mechanism with overtravel ...

通过有效设计拨轮尺寸，利用蜗轮蜗锁特，将棘轮机构与行程开关联为一，达到动输球控制目。