| 摘要 |
<p>The board or bootplate may be made of light metal. The board is designed to be suitable for use in scaffolding construction in place of the usual heavy wooden plans. The lengthways bars in this are double-t-shaped (11). They are pressed or welded in position in the same way as a normal ladder stringer bar with its transverse connectors (12), the process being the same as that for fitting rungs on a ladder. All four ends may be fitted with rubber or plastic overlays serving as buffers (15). There may be diagonally aligned zig-zag reinforcing struts (16) with rivet connection. The rungs may also be riveted to these, where they intersect. Such boards may be of considerable length, while remaining readily transportable and easily manipulated.</p> |
