Patent ID: 9670726
Date: 2017-06-06
CPC Classifications: E06C

Claim:
1. A multi-purpose ladder comprising: two ladder sections, and two articulated joints joining to the ladder sections; wherein each of the two ladder sections further comprises: two rectangular tubular inner rails attached to a plurality of inner rungs, and each of the inner rails having a side with two corners; two U-shaped outer rails, each with a plurality of outer rungs having a trapezoidal cross-sectional area viewed perpendicular to a longitudinal axis of said outer rungs, corresponding to the two inner rails and each of the outer rungs comprising an upper outer slant pedal side and a lower outer slant pedal side; wherein each of the inner rungs comprises an upper rung member, an intermediate rung member having a square cross sectional area viewed perpendicular to a longitudinal axis of said inner rung, and a lower rung member; the intermediate rung member has two ends, each end attached to a respective inner rail, and two opposite sides joining the upper rung member and the lower rung member respectively; the upper rung member and the lower rung member each have a slant pedal section, a first support section, and a second support section; each slant pedal section has a respective first lateral side and a respective second lateral side opposite to each other; each first support section joins the intermediate rung member and a respective one of said slant pedal sections at a first included angle which is forty-five degrees measured at an intersection with the intermediate rung member; each second support section is disposed beside the respective first support section and joins the intermediate rung member and the respective slant pedal section at a second included angle which is forty-five degrees measured at a second intersection with the intermediate rung member.