| 摘要 |
<p>The collapsible ladder (1) e.g. for ships comprises rungs fitted at intervals to strip side elements for stowage in a very small space for use as an escape ladder in the event of fire. The coil or strip elements (2, 3) are made of metal thread or strip and the rungs (4) are also of metal. These are all of inverted U-sectioned with diverging shanks and can be stacked one on top of another to leave a hollow space between each pair of rungs for storage of the intervening side strip sections. The metal thread may be held in holes in the rungs, formed by two interfacing pleats pressed out opposite ways. Aluminium or steel plate, less than 1 mm thick, may be used for the rungs.</p> |
