US 4,243,121 A · Web ladder release mechanism

Abstract

There is provided the combination of a frame and a collapsible ladder. The frame defines two spaced-apart horizontal passages in which catch elements are mounted. Resilient means urge the catch elements toward each other, and manual thumbscrew means are provided to pull the catch elements away from each other. A collapsible ladder has attachment means at the top by which it can be anchored, and the ladder also includes a containment means constituted by the bottom rung and two upstanding side members which register with all of the remaining rungs. The upstanding side members have openings at the top into which the catch members extend when in their innermost positions. Manual release is possible by which the side members become disengaged from the frame, thus allowing the web ladder to fall into a position of use.

Claims7

Dependent claims

In combination:

frame means adapted for attachment adjacent an opening in a building,
the frame means defining two spaced-apart, substantially horizontal passages,
a catch element mounted for reciprocation within each passage,
resilient means urging each catch element in one direction with respect to its passage,
manual means for urging each catch element against its respective resilient means,
and a collapsible ladder having attachment means by which a top end of the ladder may be anchored, the ladder also having containment means with reception means for receiving said catch elements when the latter are shifted in said one direction, whereby the containment means are retained with respect to the frame means, the containment means when so retained being adapted to maintain the ladder in collapsed condition.

3 more elements

Dependencies are inferred from the claim text.

Web ladder release mechanism

Life of this patent

Web ladder release mechanism

Life of this patent

Abstract

Claims7