Patent ID: 8210374

Claim:
A rackable, collapsible, and stackable unit comprising: two pairs of adjacent and opposite upright corner posts being foldable inwardly and downwardly; two side bars, each side bar connecting the pair of opposite upright corner posts; a pair of upper end bars, each upper end bar connecting the pair of adjacent upright corner posts; a pair of lower end bars, each lower end bar connecting the pair of adjacent upright corner posts, positioned at a point lower than the pair of upper end bars on the corner posts; at least two first core holders located on the pair of upper end bars for retaining a core; a plurality of hinges, one connected at each joint between each corner post and the side bars whereby the unit can collapse inwardly, wherein said plurality of hinges comprises at least four double-pinned hinges, each one pivotally and diagonally connected between one of the corner posts and one of the side bars; and at least four hinged support braces, each one pivotally and diagonally connected between one of the corner posts and one of the side bars to hold the corner posts in an upright position when the unit is opened and which, in combination with the hinges, makes it possible to fold the corner posts inwardly and downwardly so as to lie substantially flat against the side bars.