Collapsible support structures

In a collapsible self-sustaining support structure having a substantial measure of rigidity derived from sheetlike panel portions hingedly interconnected along common abutting edges to define fold axes for limited swinging movement towards and away from one another, said structure including a central panel portion flanked by hingedly interconnected side panel portions arranged to be supported in substantially fully extended upstanding side-by-side forwardly facing relation, said central panel portion having a uniform generally quadrilateral perimetral configuration with its uppermost edge having an extent greater than the extent of its lowermost edge, said central panel portion and said side panel portions flanking same each presenting hingedly interconnected ledge panel portions along their respective lowermost edges in side-by-side relation, the configuration of the lowermost edges of said central and side panel portions being such that said hingedly interconnected ledge panel portions are foldable in unison into a generally horizontal disposition only when said aforementioned central and side panel portions are in substantially fully extended side-by-side relation, a second central panel portion having a uniform generally quadrilateral perimetral configuration adapted to swing from a position next adjacent said first mentioned panel portion rearwardly therefrom to support same in upstanding relation and gusset panel portions hingedly interconnected between each of said flanking side panel portions and said second mentioned central panel portion and of an extent whereby with said first mentioned central and side panel portions arranged in substantially fully extended upstanding side-by-side forwardly facing relation the folding in unison of said hingedly interconnected ledge panel portions into a generally horizontal disposition secures said panels against further relative displacement.