Three-shell construction for combination ventilating and illuminating units

Claim 1

A THREE-SHELL COMBINATION VENTILATING AND ILLUMINATING FIXTURE COMPRISING A SELF-CONTAINED TWO-SHELL VENTILATING TROFFER ADAPTED TO RECEIVE A SINGLE THIRD SHELL ILLUMINATING UNIT THEREIN IN NESTING RELATION THEREWITH, SAID FIXTURE COMPRISING: A TROUGH-SHAPED FIRST SHELL HAVING OPEN ENDS; A TROUGH-SHAPED SECOND SHELL HAVING OPEN ENDS AND DISPOSED IN NESTING RELATION WITHIN SAID FIRST SHELL TO DEFINE AIR PASSAGES THEREBETWEEN, EACH OF SAID FIRST AND SECOND SHELLS HAVING A SUBSTANTIALLY RECTANGULAR TOP WALL, A PAIR OF INCLINED TRAPEZOIDAL WALL PORTIONS EXTENDING DOWNWARDLY AND OUTWARDLY FROM A FIRST PAIR OF RESPECTIVE OPPOSITE SIDE EDGES OF EACH OF SAID RECTANGULAR TOP WALLS, AND A PAIR OF VERTICAL WALL PORTIONS EACH EXTENDING DOWNWARDLY FROM THE LOWER EXTREMITY OF EACH OF A RESPECTIVE SAID INCLINED TRAPEZOIDAL WALL PORTION OF EACH OF SAID FIRST AND SECOND SHELS AND TERMINATING IN A PLANE COMMON WITH THE SURFACE OF A CEILING TO FORM AN AIR OUTLET BETWEEN SAID FIRST AND SECOND SHELLS; A PAIR OF GENERALLY VERTICALLY DISPOSED SHEET-LIKE YOKESHAPED SPACING MEMBERS DEFINING END WALL OF SAID AIR PASSAGES BETWEEN SAID FIRST AND SECOND SHELLS, EACH SAID SPACING MEMBERS LOCATED ADJCENT A SECOND PAIR OF RESPECTIVE OPPOSITE SIDE EDGES OF EACH OF SAID RECTANGULAR TOP WALLS OF SAID NESTING FIRST AND SAID SECOND SHELLS AND CONSTITUTING END PLATES OF SAID VENTILATING TROFFER TO CLOSE THE OPEN ENDS OF SAID FIRST AND SECOND SHELLS AND TO SEAL OFF THE AIR PASSAGE DEFINED BETWEEN THE ENDS OF SAID FIRST AND SECOND NESTED SHELLS; MEANS CONNECTING SAID SPACING MEMBER TO EACH OF SAID NESTING FIRST AND SECOND SHELLS; COMPRISING Z-SHAPED SPACING MEMBERS BETWEEN SAID VERTICAL WALL PORTIONS OF SAID FIRST AND SECOND SHELLS TO PROVIDE AN AIR CHANNEL BETWEEN SAID VERTICAL WALL PORTIONS OF SAID FIRST AND SECOND SHELLS COMMUNICATING WITH SAID AIR PASSAGE BETWEEN SAID FIRST AND SECOND SHELLS.