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Apparatus for use as a stairway, stepladder and the like has a pair of upper stringers and a pair of lower stringers, all connected at one end to a top structure; and a series of treads, each of which is pivoted to the upper and lower stringers. The axes of articulation associated with the upper str

Apparatus for use as a stairway, stepladder and the like has a pair of upper stringers and a pair of lower stringers, all connected at one end to a top structure; and a series of treads, each of which is pivoted to the upper and lower stringers. The axes of articulation associated with the upper stringers are offset vertically from those associated with the lower stringers so that the stringers may be swung about their points of connection with the top structure, without the treads deviating from the horizontal into a horizontal position of the stringers, in which the upper stringers rest on the lower stringers. Support elements are articulated to the top structure, and an automatic latching apparatus is provided to interconnect the support members with the stringers.

대표청구항 ▼

Apparatus for use as stairs, steps and the like, comprising; lower and upper pairs of parallel rectilinear stringers, each stringer of the lower pair being disposed below and parallel to the respective stringer of the upper pair; a pair of horizontal, parallel arms whereto first ends of the stringer

Apparatus for use as stairs, steps and the like, comprising; lower and upper pairs of parallel rectilinear stringers, each stringer of the lower pair being disposed below and parallel to the respective stringer of the upper pair; a pair of horizontal, parallel arms whereto first ends of the stringers are articulated about respective arms pivot axes extending between the arms, one of said axes supporting the lower stringers and being spaced downwardly from another one of the arm pivot axes, said other one supporting the upper stringers; a plurality of treads mounted on and between the stringers, each tread having lower tread pivot means connecting it to the lower stringers at and about a lower tread pivot axis, and each tread having upper tread pivot means connecting it to the upper stringers at and about an upper tread pivot axis, the tread pivot axes being spaced apart longitudinally of the stringers by distances approximately equal to the widths of the treads and being spaced apart vertically by a distance approximately equal to said predetermined vertical distance between the arm pivot axes; and two elongate support elements articulated between the horizontal arms, each such element having a post perpendicular thereto and having post pivot means pivoted to one of the horizontal arms so that the support elements can be turned from a support position below the horizontal arms to a rest position above the horizontal arms; whereby the stringers and the support elements can be turned relative to the horizontal arms, while the treads are and remain horizontal.