当要增加下面空间时，将内框抬起然后向后退，后面有支架上的止动杆件起止退作用。

When the lower space needs to be increased, the internal frame is lifted upwards and then moved backwards, and a check bar arranged on the supporting frame plays the action of stopping the retreat.

youdao

当要增加下面空间时，将内框抬起然后向后退，后面有支架上的止动杆件起止退作用。

When the lower space needs to be increased, the internal frame is lifted upwards and then moved backwards, and a check bar arranged on the supporting frame plays the action of stopping the retreat.

youdao