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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 o

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.

대표청구항 ▼

1. A segment suitable for use in a portable tower, the segment comprising: a body having a first panel with an outwardly facing surface and an inwardly facing surface, a second panel with an outwardly facing surface and an inwardly facing surface, a first side wall, a second side wall, a top end and

1. A segment suitable for use in a portable tower, the segment comprising: a body having a first panel with an outwardly facing surface and an inwardly facing surface, a second panel with an outwardly facing surface and an inwardly facing surface, a first side wall, a second side wall, a top end and a bottom end, with the first and second panels extending between the side walls, the first and second panels spaced from each other and confronting one another, and the first and second panels connected to each other by plurality webs;the first panel having a first set of transverse slots, the first set of slots extending from the top end to the bottom end; andthe second panel having a first raised portion on the outwardly facing surface of said second panel, the first raised portion being positioned directly rearward of said first set of transverse slots. 2. The segment of claim 1, and further including a first web extending between the inwardly facing surfaces of said first and second panels and positioned between the first set of transverse slots of said first panel and said first raised portion of said second panels. 3. The segments of claim 1, wherein: the first panel has a second set of transverse slots, the second set of transverse slots extending from the top end to the bottom end and spaced laterally from said first set of transverse slots;the second panel has a second raised portion on the outwardly facing surface of said second panel, the second raised portion being positioned directly rearward of said second set of transverse slots; andeach of said first and second sets of spaced apart transverse slots being located adjacent said first and second side walls, respectively, of the body. 4. The segment of claim 3, and further including a second web extending between the inwardly facing surfaces of said first and second panels and positioned between the second set of transverse slots and said second raised portion. 5. The segment of claim 4, and further including: a third web extending between the inwardly facing surfaces of said first and second panels and positioned adjacent said first web and spaced from said first web with said first web on one side of said first set of transverse slots and said third web positioned on the remaining side of said first set of transverse slots, said first and third webs cooperating to maintain a fixed distance between the first and second panels; anda fourth web extending between the inward facing surfaces of said first and second panels and positioned adjacent said second web and spaced from said second web with said second web on one side of said second set of transverse slots and said fourth web positioned on the remaining side of said second set of transverse slots, said second and fourth webs cooperating to maintain a fixed distance between the first and second panels. 6. The segment of claim 4, wherein: said first web extends from the top end to the bottom end of the body and is spaced from said first side wall to define a first elongated aperture between said first web and said first side wall, said first aperture extending from the top end to the bottom end of said body,said second web extends from the top end to the bottom end of the body and is spaced from said second side wall to define a second elongated aperture between said second web and said second side wall, said second aperture extending from the top end to the bottom end of said body;the segment further including: a first pair of pivot support blocks, a said pivot support block extending upward from each of said first and second apertures at the top end of the body;a second pair of pivot support blocks, a said pivot support block extending downwardly from each of said first and second apertures at the bottom end of the body; andwherein each said pivot support block has a bearing aperture therein.