| 摘要 |
<p>The ladder is of the type with rungs hinged to the stringers, and fixable in the operative position by one or more bolts locking onto a stringer. The stringers (19, 21) are connected by hinge units (15, 16) at their top ends (13, 14) to the stringers (20 22) of a second, similar ladder section (12) for conversion into a step-ladder (10). The hinge units can comprise two flat interconnected hinge strips, with combined thickness not exceeding the width of the stringers. At the bottom ends (29, 30) the ladder sections (11, 12) may be connected by a draw chain or similar unit (31) which is detachable from one section.</p> |
