US 4,067,413 A · Collapsible ladders

Abstract

A collapsible ladder for use as an emergency escapeway is described which has two side members between which rungs extend. The side members are each composed of a plurality of sections, which are pivoted to each other at overlapping ends. In one embodiment, the rungs extend between alternate pairs of the sections, while the intermediate sections are provided with fender spars which fold parallel with the section, and swing into position to space the ladder away from a wall, when the ladder is unfolded. The sections are held in place relative each other on unfolding of the ladder by a pin on one section received in an arcuate slot partially surrounding the pivot of the next section. In a modified embodiment each section has at each end adjacent the pivot a stud and a recess, which engage complimentary recesses and studs on the adjacent sections.

Claims5

Dependent claims

A side member for a collapsible ladder, comprised of a plurality of sections having an aperture at each end for pivoting to a further similar section, wherein adjacent ones of said sections are mounted on a pivot pin extending through their respective apertures, and their faces upon which the respective projections and recesses are provided are disposed so as to face one another, so that the projections on each face will engage on the recesses in the other face and wherein the said faces of the sections are biased into abutment by a spring mounted on each pivot pin.

A collapsible ladder comprising:

a. a plurality of rungs, each extending between two side members, each side member being composed of a plurality of sections, each articulated to an adjacent section on at least one end region thereof,
b. the rungs extending between and being secured at each end to intermediate regions of alternate pairs of said sections,
c. gravity operable fender struts pivotally mounted on each side member at alternate points of articulation between adjacent side member sections,
d. a stud or projection formed on one face of each section adjacent at least one of the points of articulation,
e. a recess for reception of such a stud or projection formed on said face of each section adjacent at least the other of said points of articulation, the said faces of adjacent sections being disposed in face-to-face relationship in said end regions,
f. articulation between said sections at each said point of articulation being by way of a pivot pin passed through apertures in said sections, said pivot pin providing a seat for a spring which is also seated against the face of one of the sections opposite its said one face to bias the sections into contact, whereby said projections are pushed into said recesses when they become aligned, in response to said spring, to hold the latter substantially rigid.

3 more elements

Dependencies are inferred from the claim text.

Collapsible ladders

Life of this patent

Collapsible ladders

Life of this patent

Abstract

Claims5