US Patent 7722138 Storage cabinet

A file cabinet includes a foldable sheet metal housing wrapper or individual side panels which define a back wall and the left and right side walls of the cabinet. A reinforcement box or insert is permanently affixed within the back of the cabinet which reinforcement box is spaced forwardly of the back wall to define a strengthening column which rigidifies the overall housing structure. Upper and lower cross rails are secured to the upper and lower corners of the side walls at the front of the cabinet to rigidify the front of the cabinet. The opposite ends of the cross rail have depending flanges which are fixedly secured to vertical tubular edge supports formed integrally in the side walls.