| 摘要 |
<p>PURPOSE:To provide a double ladder with safety frame for preventing a fall. CONSTITUTION:Both a lower ladder 1 and an upper ladder are perfectly provided with safety frames 3, 4, and the lower safety frame 3 is formed into a frame structure capable of passing in the upper safety frame 4, whereby safety performance and the expanding contracting performance as double ladder are ensured. Both the safety frames 3, 4 are constituted in the combination of several pieces of frame stiffness 15, 19 attachably and detachably supported by step beams 11, 13 and a lateral pair of connecting rods 17, 21 pivotally fixed continuously thereto, whereby the safety frames 3, 4 can be folded, and a partially released state in which the frame stiffness 15, 19 are hooked by the connecting rods 17, 21 can be performed. The connecting rod 17 of the lower safety frame 3 is formed into a channel form of dovetail groove to which the connecting rod 21 of the upper safety frame 3 is inserted, whereby the lower safety frame 3 and the upper safety frame 4 can be integrally folded.</p> |
