| 摘要 |
<p>The spiral staircase with a hollow metal core (1) is arranged between a support (2, 7, 16) at a lower floor and a summit plate (3) at an upper floor in a house or a building for offices. The core carries the steps (4) separated by sleeves (5, 5"). The metal core is subdivided into two sections of which one (11, 15, 15", 20) has an excess length allowing to cut it on site to adapt it to the required height of the staircase, and of which the other (10, 18) is terminated and may be telescopically mounted on the first one. At least two holes are drilled through the telescopic sections. A high strength rod (14, 14") is pressed into these holes so as to make these two sections solid with each other on site. </p> |
