| 摘要 |
Laterally retractable steps, with instant opening and closure, characterised principally by half-steps, each one formed by several rungs (4) pivoting on two lateral uprights (1) and (2) and on a central upright (3), which is parallel and equidistant to the latter, by means of hinges (7) and (9). On being folded up, these rungs engage between the uprights, whereas in the use position their upper faces come into one and the same horizontal plane in order to support the foot. Generally numbering two, the rungs are formed by the assembly of three parts (5), (6) and (8), and the opening or closure manoeuvre is effected with the aid of a lever (15). These steps are of a novel type and will permit practical access to an upper level when a fixed stairway cannot be installed, both in existing constructions and in new structures. <IMAGE> |
