Ceiling illuminating system

Claim 1

AN ILLUMINATING, SOUND-ABSORBENT CEILING COMPRISING A MULTIPLICITY OF ELONGATED GRID MEMBERS ADAPTED TO BE SUSPENDED HORIZONTALLY FROM OVERHEAD STRUCTURE, EACH GRID MEMBER BEING PROVIDED WITH AN ELONGATED UPPER SURFACE, ACOUSTICAL SHEET MEANS HAVING A LIGHT REFLECTIVE LOWER SURFACE DISPOSED OVER AND SUPPORTED AT LEAST IN PART BY SAID GRID MEMBER UPPER SURFACES, AT LEAST SOME OF SAID GRID MEMBERS BEING SPACED APART FROM AND PARALLEL WITH ADJACENT GRID MEMBERS FORMING A PLURALITY OF GRID MEMBER PAIRS, A PLURALITY OF ELONGATED LIGHT TUBE MEANS, MEANS SUPPORTING EACH LIGHT TUBE MEANS BETWEEN A SAID PAIR OF GRID MEMBERS AND PARALLEL THEREWITH BELOW SAID LOWER SURFACE OF SAID ACOUSTICAL SHEET MEANS, EACH GRID MEMBER DISPOSED ALONG THE SIDE OF A LIGHT TUBE MEANS HAVING A GENERALLY CONTINUOUS SURFACE PARALLEL WITH THE CORRESPONDING LIGHT TUBE MEANS AND EXTENDING DOWNWARDLY TO A LOWER HORIZONTAL EDGE BELOW SAID LIGHT TUBE MEANS, A PLURALITY OF LIGHT-SHIELDING MEANS, ONE DISPOSED BELOW, ALONG THE LENGTH OF EACH LIGHT TUBE MEANS, EACH LIGHTSHIELDING MEANS BEING SUBSTANTIALLY NARROWER THAN THE SPACE BETWEEN THE GRID MEMBERS OF THE CORRESPONDING PAIR BUT WIDER THAN THE CORRESPONDING LIGHT TUBE MEANS, HAVING EACH LONGITUDINAL UPPER EDGE SPACED ASIDE FROM THE CORRESPONDING SIDE OF SAID LIGHT TUBE MEANS, EACH LIGHT TUBE MEANS, ITS LIGHT-SHIELDING MEANS, AND THE CORRESPONDING PAIR OF GRID MEMBERS BEING RELATIVELY POSITIONED SO THAT A LINE OF SIGHT THROUGH EACH LIGHT-SHIELDING MEANS LONGITUDINAL UPPER EDGE AND THE LOWER INNER EDGE OF THE CORRESPONDING GRID MEMBER INTERSECTS THE HORIZONTAL AT AN ANGLE NO LESS THAN THAT OF A LINE OF SIGHT BETWEEN THAT SHIELDING MEANS EDGE AND THE UPPER LIMB OF THE CORRESPONDING LIGHT TUBE MEANS.