Patent ID: 8020224

Claim:
A mattress foundation comprising: a substantially rectangular frame comprised of interconnected and intersecting frame members; a wire grid; a plurality of similarly formed springs which are interconnected in an array or matrix and located between the frame and the grid; four internal corner structures, one located at each corner of the frame between the frame and the grid, said internal corner structures comprising: a generally planar base member dimensioned to fit within the width dimension of a top surface of the foundation frame members with three generally linear sides and an arcuate transition between two of the linear sides and containing two flanges located along the arcuate transition that extend down over the foundation frame member and a tongue, which is a planar member that extends horizontally from the three generally linear sides and contains two staple arches that sit parallel to each other; a body structure located on top of the base member which has an exterior profile that includes a rounded corner and three generally linear sides with a lattice pattern made up of a plurality of square shaped openings extending both vertically and horizontally across the structure; a grid support deck located on top of the body structure that has a generally planar surface with three linear sides and an arcuate transition between two of the linear sides and containing an edge guard located at the center of the arcuate transition, two engagement clips located at opposite ends of the arcuate transition, and two notches used to receive the two staple arches upon nesting of two corner structures.