| 摘要 |
<p>A collapsible ladder is disclosed wherein adjacent side pieces of the ladder are straps (21, 22) pivotally secured to each other and lockable in an extended position in inwardly spring-urged bolts (51) the release of which bolts can only be achieved by dexterous manipulation of spring means (49) which urge the bolts into locking engagement. The locking engagement occurs automatically when the two adjacent straps are aligned in a coextensive position. The advance in the art is in a structural simplicity combined with making it virtually impossible to inadvertantly release the locked connection between adjacent links of the ladder even if the ladder is subjected to extreme forces or impact.</p> |
