US Patent 7562897 Collapsible transport cart

A collapsible transport cart includes a bottom wall with a planar top surface, and a plurality of apertures formed in opposed corners thereof. First and second axially opposed walls are attached to the bottom wall, and third and fourth walls are attached to opposed longitudinal edges thereof. A plurality of brackets is removably mated with top edges of the walls such that a rectangular cavity is defined within an interior perimeter thereof. A plurality of shelves and caster assemblies is adjustably mated to the bottom wall. A mechanism adjustably and removably supports the shelves within the cavity such that the shelves remain statically nested within the cavity when the walls are biased to a horizontal and open position.