Collapsible self-supporting structures and panels and hub therefor

Claim 1

An assembly of pivotally connected rod elements capable of being manipulated from a bundled, collapsed condition to an expanded, self-locking erected condition forming a self-supporting structure, said assembly comprising, in combination: a plurality of pairs of crossed rod elements pivotally joined in scissored fashion substantially midway between their ends, one rod element of each pair being pivotally joined at its opposite ends to two other rod elements of adjacent pairs of rod elements and the other rod element of said each pair being pivotally joined at its opposite ends to the remaining two rod elements of said adjacent pairs of rod elements, whereby the pivotally connected ends of said pairs of rod elements lie at the corners of first and second similar polygons situated in spaced, parallel planes such that as the pairs of rod elements are scissored, the assembly is moved between a collapsed condition in which the first and second polygons are of contracted size and their planes are maximally spaced and an erected condition in which the first and second polygons are of expanded size and their planes are spaced relatively close; and further rod means pivotally joined together and to corners of said polygons for self-locking said assembly in said erected condition, said further rod means comprising a first set of rod elements pivotally joined together at the plan view geometric center of said first polygon and extending therefrom to pivotally connect to corners of said first polygon, said rod elements of said first set being of lengths such that they lie essentially in a common plane containing said corners of said first polygon when said first polygon has expanded to a maximum size, said further rod means also including a second set of rod elements pivotally joined to corners of said second polygon and to intermediate portions of corresponding rod elements of said first set so that said rod elements of the second set cannot be essentially in a common plane containing the corners of said second polygon even when the assembly is in erected condition; said rod elements of said second set being of lengths between their corner-connected ends and their pivotal connections to the corresponding rod elements of said first set such that as said polygons are expanded, the rod elements of said first and secoond sets thereof interact to place all of the rod elements of said assembly under cumulative self-locking stress in said erected condition of the assembly.