| 摘要 |
<p>A portable riser having a plurality of steps which have a travel position in superimposed relation with structure for rolling the riser along the floor, hinge means interconnecting the steps whereby they may be folded out of superimposed relation, a pair of sliders pivotally associated with each step and which are hinged to sliders of an adjacent step by said hinge means whereby lifting of one step causes erection of the riser to an erected position, and latch means automatically operable to prevent movement of the steps beyond erected position and to lock the riser in erected position for use.</p> |
