US 12,454,831 B2
Folding stair with tread overhang
Matthew Yeatman Herzl, Marshall, AR (US)
Filed by Matthew Yeatman Herzl, Marshall, AR (US)
Filed on Apr. 18, 2023, as Appl. No. 18/302,619.
Claims priority of provisional application 63/332,908, filed on Apr. 20, 2022.
Prior Publication US 2023/0392383 A1, Dec. 7, 2023
Int. Cl. E04F 11/06 (2006.01); E04F 11/022 (2006.01); E04F 11/025 (2006.01); E04F 11/032 (2006.01)
CPC E04F 11/064 (2013.01) [E04F 11/0223 (2013.01); E04F 11/025 (2013.01); E04F 11/032 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A folding stair, comprising:
(a) a structure,
(b) a sequence of steps, together forming a traversal path,
each with a substantially flat tread,
each with a thickness,
each with a width,
each with a depth,
each except the top step with a rise,
each except the top step with a run,
(c) wherein for each step with a rise in said sequence, the step's width exceeds said rise,
(d) wherein for each step with a run in said sequence, said step exhibits tread overhang,
(e) for each step in said sequence, an axis rotably mounting said step to said structure, which guides the step's rotation between a deployed state, in which the steps of said sequence together form said traversal path, and a stowed state,
(f) wherein each said axis is substantially to one side of its step,
(g) wherein each said axis is to the same side of its step,
(h) wherein for each step with a rise in said sequence, the orientation of said axis facilitates the angle of rotation between said deployed state and said stowed state to exceed the arccosine of the ratio whose denominator is the step's rise and whose numerator is the step above's thickness,
whereby, said stair exhibits both foldability and tread overhang.