Radial expansion/retraction truss structures

Abstract

A loop-assembly is disclosed which is comprised of at least three scissors-pairs, at least two of the pairs comprising: two essentially identical rigid angulated strut elements, each having a central and two terminal pivot points which do not lie in a straight line, each strut being pivotally joined to the other of its pair by their central pivot points, each pair being pivotally joined by two terminal pivot points to two terminal pivot points of another pair such that both scissors pairs lie essentially in the same plane, or each pair being pivotally joined by two terminal pivot points to two terminal pivot points of another pair in that the terminal points of a scissors-pair are each pivotally joined to a hub element, and these hub elements are in turn joined to the terminal pivot points of another scissors-pair, whereby a closed loop-assembly is thus formed of scissors pairs, and this loop-assembly can fold and unfold, and a line that intersects and is perpendicular to the axes of any two terminal pivot points is non-parallel with at least two other similarly formed lines in the assembly, the angles formed between said lines remaining constant as the loop assembly is folded and unfolded.

Dependencies are inferred from the claim text.