图中这种梯子既可以作为人字梯凳使用,又可以作为伸缩梯用。它由两扇铝制的梯架构成。在梯架连接端部的两侧都各有一个连接臂,这根臂可以绕一根转轴旋转,同时也可以沿铝制梯架立柱上的导槽滑动。当把这两扇梯架撑开呈人字形时,它就成了梯凳。当高度不够时,只要把两扇梯架合拢,并使其中一扇沿 In the picture, the ladder can be used as a ladder ladder or as an extension ladder. It consists of two aluminum ladders. There is a connecting arm on each side of the connecting end of the ladder frame. The arm can rotate around a rotation axis, and can slide along the guide groove on the aluminum ladder frame. When the two ladders were stretched into a herringbone, it became a step stool. When the height is not enough, just close the two ladders and make one of them