Elongated, upright supporting element

Claim 1

A COLLAPSIBLE AND EXPANDABLE STRUCTURAL ASSEMBLY COMPRISING A PLURALITY OF ELEMENTS JOINED TOGETHER AND AT LEAST TWO OF SAID ELEMENTS EACH CONSISTING OF A PLURALITY OF SIDE PANELS INTRECONNECTED BY LONGITUDINALLY EXTENDING FOLD LINES WITH SAID SIDE PANELS BEING COLLAPSIBLE AND EXPANDABLE ABOUT THE FOLD LINES AND THE EXPANDED SIDE PANEL DEFINING A HOLLOW TUBULAR BODY HAVING TWO OPEN ENDS AND TAPERING ALONG ITS ENTIRE LENGTH BETWEEN SAID OPEN ENDS SO THAT SAID BODY HAS AT ONE END A CROSS SECTION SMALLER THAN THAT AT THE OTHER OF ITS ENDS, A FLAP IN THE REGION OF SAID ONE END OF SAID BODY CONNECTED TO ONE OF THE SIDE PANELS BY A FOLD LINE AND SAID FLAP BEING SHAPED TO EXTEND ACROSS THE HOLLOW BODY INTO CONTACT WITH THE OTHER SIDE PANELS AT SAID REGION OF SAID ONE END OF SAID BODY WHEN SAID FLAP IS BENT INWARDLY SO AS TO LEND RIGIDITY TO SAID HOLLOW BODY, AND SAID ONE END OF ONE OF SAID TWO ELEMENTS BEING INSERTED AND TELESCOPICALLY WEDGED INTO THE OTHER OF SAID ENDS OF THE OTHER OF SAID ELEMENTS, SO THAT SAID TWO ELEMENTS OF SAID ASSEMBLY FORM A SUBSTANTIALLY RIGID PORTION THEREOF.