Patent ID: 7044312

Claim:
A multi-purpose tubular frame structure, comprising: a shelf rack having: an adjustable shelf; a horizontal tube that supports the shelf, and having a cleat block at respective extremities thereof, each said cleat block having a trapezoidal configuration, and outwardly projecting coupling flanges on lateral sides thereof, each coupling flange having essentially an L-shape in cross-section defined by a first leg and a second leg; and a plurality of corner posts, each having a series of differing height retaining holes therein, the retaining holes providing for the engagement of a respective cleat block, each retaining hole being a semi-trapezoidal opening with the sides at a lower half being gradually angled inward, and the first legs of the coupling flanges of each cleat block are disposed to correspond to a shape and dimension to the semi-trapezoidal opening, to allow the flanges to be insertable within the selected semi-trapezoidal openings, and the second legs of the coupling flanges of each cleat block define a coupling surface that is slightly larger than the semi-trapezoidal opening, which is engagable with respective interior lateral sides of the semi-trapezoidal openings when the flanges are inserted therein.