| 摘要 |
<p>The securing rungs, or treads, to vertical hollow section supports, includes, in the case of round rungs, riveting over the end (2) against the outside face, after the end has been fitted between the two hollow parts (3). At the same time, screwe or rivets (8) are inserted through tongues (7) projecting from the inside face of the support member (4). A square section rung can be similarly secured. In the case of a wider tread (9), the tread surface can be shaped to fit around one hollow part (4) with an end extended to form a tongue (12) which can be secured by a screw or rivet. Many designs of tread are secured using these basic principals.</p> |
