US Patent 10030379 Extendable/retractable support column

An extendable and retractable column which is formed from at least three linked sections or chains. The linked sections include a plurality of individual segments linked end to end. As the linked segments are extended, each of the individual segments of the linked chains engage individual segments of adjacent linked sections to form a column. As the linked sections are retracted, each of the individual segments of the linked sections disengage from the individual segment of the adjacent linked sections and the individual linked sections may be rolled up into a multi-sided form for compact storage.