| 摘要 |
<p>The device, according to the present invention comprises string boards (2) with staircase steps (1) arranged thereon. A railing formed by vertical posts (12) and a handrail (13) is attached to the string boards (2). Both ends of the string boards (2) are strongly anchored. A coupling (7) having a hole (6) and a through groove (5) is fixedly attached to each end of the steps (1). The head of one bolt (3) is placed in rotating manner in the hole (6) while the head of the other bolt (3) is placed in rotatable and slidable manner in the through groove (5). One bolt (3) is fastened in the string board (2), while the other bolt (3) is fastened in a sliding part (14) that slides longitudinally on the string board (2) flank. At the same time the posts (12) are attached to both the handrail (13) and the string boards (2) in such a manner to be able to perform longitudinal swing, whereby the extreme posts (12) bottom ends are extended.</p> |
