Abstract: A portable folding ladder comprising a plurality of U-shaped modules having a rung and two vertical portions, the modules movable connected to each other, and when opened becoming progressible narrower as they approach the top of the ladder, when folded the narrower modules fitting inside of the next wider modules and locking means to lock the modules in a rigid manner which when the ladder is extended and open.

Abstract: This invention relates to a detachable top to be used with foldup ladders of the type described in co-pending applications Ser. Nos. 06/341,830; 06/492,487; and 06/537,276. Also, this top can be used with the slidable ladder described in U.S. Pat. No. 4,429,766. This ladder can be converted into many structures such as a workbench, table or step ladder. The top comprises a rectangular main portion and a narrower extending section. The main portion fits over and around the rails of the ladder (after conversion to a workbench) and the narrower extending section fits inside the rails but on substantially the same plane as the main portion.

Abstract: A portable folding ladder comprising a plurality of U-shaped modules having a rung and two vertical portions, the modules movable connected to each other, and when opened becoming progressible narrower as they approach the top of the ladder, when folded the narrower modules fitting inside of the next wider modules and locking means to lock the modules in a rigid manner when the ladder is extended and open.

Abstract: A portable and convertible ladder comprising a series of u-shaped modules each movably connected to the other by hinge means, said modules having progressively decreasing widths as they approach the top of the ladder when in an open mode, said modules having a base or rung portion and upright sections, each module having locking means movably positioned in their lower portion, and adapted to form a substantially rigid ladder when in an open mode, each module except for the uppermost module having hinge means at substantially the upper portion of said upright sections, said locking means having a locking member positioned in said lower portion adapted to fit and mate with complimentary male or female member positioned in an adjacent portion of said upright sections, at least a section of the wider of said modules overlapping at their upper vertical portions with the bottom portions of the next adjacent narrower modules, and said locking means and said module hinge means provided in said overlapping portions.

Abstract: A sliding section ladder, comprising sections of varying widths made up of u-shaped modules, comprising a base and upright sections, each module being smaller in width than the one immediately before it, the outer sides of the smaller module backing into the inside of the immediately larger module, whereby the base and upright sections of the u-configuration of the smaller module are adjacent to the u-shaped base and upright sections of the larger module when said ladder is in a closed position.