Prefabricated metal stairway

Claim 1

A prefabricated permanent metal exterior stairway for a twostory building comprising: a generally rectangular ground-bearing base having longitudinal members and transverse members, said base being adapted to uniformly distribute a vertical load about the perimeter thereof; a landing structure at one end of said base including vertically extending newel posts mounted at each corner of said base and paired, transversely aligned, vertically extending newel posts, one of each pair mounted on each longitudinal base member, horizontal channels connecting said newel posts intermediate their ends to define an open frame which is parallel to said base and vertically spaced intermediate the first and second floor levels, and a deck mounted on said frame to constitute a landing; a first run of steps extending from the transverse member at the end of the base opposite said landing structure, to said landing; a second run of steps, extending from said landing to the second floor level; newel posts, linked to the transverse base member at which said first run originates, said posts supporting the terminus of said second run and one of said posts being common to the ground level of said first run and the top of said second run; said stairway thus posting all of its loads to said base and having a triangulation rigidity including that attributable to the internal trussing provided by the co-planar presence of the edges of the two runs of stairs and a common newel post.