초록 ▼

Ladder structures are disclosed comprising a pair of side rails and a plurality of tubular extruded aluminum rung members extending therebetween. The opposite ends of each rung are interconnected with the corresponding side rail by means of an expandable fastener extending through an opening in the

Ladder structures are disclosed comprising a pair of side rails and a plurality of tubular extruded aluminum rung members extending therebetween. The opposite ends of each rung are interconnected with the corresponding side rail by means of an expandable fastener extending through an opening in the rails and into the rung end. The openings in the rails and rung are non-circular and the corresponding portions of the fastener are non-circular, whereby rotation of the fastener and rung relative to the side rail is precluded.

대표청구항 ▼

A ladder comprising, spaced apart rail members and a plurality of rungs extending therebetween, said rail members having corresponding inner and outer surfaces, each rung having opposite ends facing the inner surface of a corresponding one of said rail members, each of said opposite ends having a no

A ladder comprising, spaced apart rail members and a plurality of rungs extending therebetween, said rail members having corresponding inner and outer surfaces, each rung having opposite ends facing the inner surface of a corresponding one of said rail members, each of said opposite ends having a non-circular opening extending axially inwardly of said rung, each of said rail members having a non-circular opening therethrough axially aligned with the opening in the corresponding end of said rung, and expandable fastener means interconnecting each of said opposite ends of said rung with the corresponding rail member, said fastener means including first and second non-circular portions respectively in said rung opening and said rail member opening and of complementary non-circular configuration and dimension with respect to the corresponding opening so as to interengage therewith to prevent rotation of said fastener means and rung relative to said corresponding rail member, said first portion including radially displacable legs in said rung opening, and said fastener means further including means engaging the outer surface of the corresponding rail member to position said first and second portions axially of said openings and a member displacable relative to said legs to radially spread and wedge said legs of said first portion against the inner surface of said rung opening.