Patent ID: 6739098
Filing Date: 2004-05-25
Classification: E04B,E04C

Abstract:
A retractable structure comprising a plurality of linkages,each of said linkages comprising a plurality of link-pairs, each of said link-pairs comprising two panel-links, each of said panel-links having a polygonal profile and at least three pivots, one central pivot and at least two end pivots, wherein each panel-link is joined to the other panel-link of its link-pair by their central pivots, and each link-pair is joined to one or more neighboring link-pairs by two end pivots, each link-pair lying in a different plane than its neighboring pair, whereby in its extended position the polygonal profiles of the panel-links overlap so that a continuous triangle-shaped surface is formed, whereby each end pivot of every panel-link lies in one of two common planes with an angle formed between said planes, and that a tongs-linkage thus formed may be freely extended and retracted, so that for any position of the linkage, each end pivot continues to lie in one of two planes which form an angle between them, said angle being unchanged for any position.