Ladder structure
First Claim
1. An improved ladder structure comprising at least one pair of elongate stiles with a plurality of rungs extending between and connected on either end with said stiles:
- said rungs provide two substantially flat and opposing faces, adjoined on either side by a pair of arcuate faces;
said elongate stiles are hollow, each traversed along its length by an opening, interrupted at pre-determined intervals by a plurality of entrances defined by semi-circular arcs along the edges of said opening, the radius of said semi-circular arcs being substantially equal with the radius of curvature of said arcuate faces of said rungs, whereupon said rungs can be inserted into said stiles through said entrances and upon rotation through a suitable angle, said arcuate faces of said rung will rest against the edges of said semi-circular arcs of said entrances;
each said rung having a pair of support elements, one said support element disposed on each end of said rung, rigidly secured to said rung with a first attachment means;
said support elements, rigidly secured to said rung, are attached to a respective said stile with a second attachment means.
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Accused Products
Abstract
An improved ladder structure comprising a pair of stiles, a plurality of rungs, and a plurality of brackets. Wherein, each bracket consisting of two parallel arms, with a securing hole formed on each parallel arm, and a connecting surface running between the parallel arms, with a rivet hole formed thereon. Each rung has a pair of insertion recesses formed on either end, each recess being diametrically opposed with the other. At a predetermined distance inwards form each insertion recess is formed an insertion slot. Both the insertion recesses and insertion slots pass through one of a pair of through-holes formed internally on opposing arcuate surfaces of a rung, extending from one end to the other. Whereby, on either end of a rung, a pair of opposing brackets are inserted into corresponding insertion slots and insertion recesses, and subsequently secured in place by insertion of dowel pins into the through-holes. Each stile has a C-shaped cross-section with an opening running along its length, interrupted by semi-circular arcs defining entrances for corresponding rungs. An end of a rung is positioned within a stile so as to abut the arcuate surfaces of the rung against the arcuate edges of the stile entrances and align the rivet holes of the pair of opposing brackets with a corresponding pair of side holes formed on either side of the opening. Whereupon, a pair of pull-mandrel rivets secure the brackets to the stile.
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Citations
4 Claims
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1. An improved ladder structure comprising at least one pair of elongate stiles with a plurality of rungs extending between and connected on either end with said stiles:
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said rungs provide two substantially flat and opposing faces, adjoined on either side by a pair of arcuate faces; said elongate stiles are hollow, each traversed along its length by an opening, interrupted at pre-determined intervals by a plurality of entrances defined by semi-circular arcs along the edges of said opening, the radius of said semi-circular arcs being substantially equal with the radius of curvature of said arcuate faces of said rungs, whereupon said rungs can be inserted into said stiles through said entrances and upon rotation through a suitable angle, said arcuate faces of said rung will rest against the edges of said semi-circular arcs of said entrances; each said rung having a pair of support elements, one said support element disposed on each end of said rung, rigidly secured to said rung with a first attachment means; said support elements, rigidly secured to said rung, are attached to a respective said stile with a second attachment means. - View Dependent Claims (2, 3, 4)
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Specification