Delineated ceiling grid in suspended ceiling

Claim 1

A suspension ceiling comprising, in combination: a rectangular grid structure and a plurality of rectangular ceiling panels, said grid structure including a plurality of spaced-apart substantially parallel first runners and a plurality of spaced-apart substantially parallel second runners extending substantially perpendicular to said first runners, said first and second runners cooperating to form grid openings for receiving said rectangular ceiling panels; said runners being connected together by joints located at each corner of each rectangular opening, said joints providing a through runner extending through said joint and a pair of opposed runners terminating adjacent to the associated through runner, each opposed runner providing connecting means connecting the end thereof to said through runner, said connecting means being structured to prevent any substantial movement of the ends of said opposed runners toward each other beyond their normal connected position, said runners having an inverted generally T-shaped structure with a stiffening spine longitudinally disposed thereon, web means depending from said spine and first and second outwardly extending flanges connected to the lower portions of said web means by first and second connector portions, respectively, said first and second flanges lying generally in a common plane perpendicular to said web means and said first and second connector portions being displaced out of plane of said flanges in a direction toward said web means to establish a longitudinal recess along each T-shaped structure exposed to view from below the ceiling grid, a junction line between each flange and the respective connector portions, each said ceiling panel having a length and width dimension substantially equal to the dimensions between opposite junction lines within a given rectangular grid opening whereby if a ceiling panel is not properly centered in the grid opening so that the horizontal bottom surface of said ceiling panel rests on the flanges but instead one edge of the panel rests on a connector portion, the vertical spacing between the panel bottom surface and the respective flanges is observable from below the ceiling, said connector portions also operating to maintain a panel in its proper centered position; said connecting means by preventing longitudinal movement of adjacent ends of said opposed runners at said joints preventing said opposed runners from causing the adjacent flanges of said through runners to be displaced toward each other by any material amount, the flanges and a portion of said connector portions of said through runners providing notches at about 45° at said joints, and the ends of said flanges and at least a portion of said connecting portion at the ends of said opposed runners being shaped to mate with associated notches and provide a miter joint along both said flanges and said longitudinal recess, said notches terminating at an inner end spaced along said connector portions from said flanges whereby a portion of said connector portions extends past said notches to provide stiffness to said through runners through said joints, said portions of said connector portions extending past said notches being sufficiently small so that they do not materially detract from the appearance of said miter joints.