Ventilated ceiling construction

Claim 1

IN A VENTILATED CEILING CONSTRUCTION OF THE TYPE HAVING A PLENUM CHAMBER, INCLUDING A CEILING SUSPENDED BELOW THE MAIN CEILING, SAID SUSPENDED CEILING COMPRISING FURRING CHANNELS HUNG FROM THE MAIN CEILING, CHANNELS EXTENDING AT RIGHT ANGLES TO THE FURRING CHANNELS AND SECURED THERETO, SAID SUSPENDED CEILING COMPRISING RECTANGULAR PANELS, EACH HAVING A KERF IN AND EXTENDING THE LENGTH OF EACH EDGE THEREOF, THE CHANNELS HAVING OUT-TURNED FLANGES LODGED IN SAID KERFS AND MOUNTING THE PANELS; THE COMBINATION THEREWITH OF VENT SPLINES MOUNTED BETWEEN THE PANELS AND CARRIED THEREBY, EACH VENT SPLINE COMPRISING AN ELONGATED U-SHAPED MEMBER HAVING AN ELONGATED BODY PORTION WITH A PAIR OF SPACED PARALLEL DEPENDING LEGS, EACH OF THE LEGS HAVING A LONGITUDINAL GROOVE IN ITS INNER SURFACE EXTENDING THE LENGTH THEREOF AND DEFINING A SHOULDER PARALLEL TO AND NEAR THE TOP OF EACH LEG, A PAIR OF FINS EXTENDING LATERALLY OUTWARDLY FROM THE ELONGATED BODY PORTION OF THE VENT SPLINE ALONG THE LENGTH THEREOF LODGED IN THE CORRESPONDING KERFS OF THE ADJACENT PANELS AND CARRIED THEREBY, WITH THE ELONGATED BODY PORTION OF THE SPLINE INTERVENING BETWEEN THE ADJACENT EDGES OF THE PANELS, SAID ELONGATED BODY PORTION HAVING APERTURES THERETHROUGH FOR PASSAGE OF AIR BETWEEN THE PLENUM AND THE ADJACENT ROOM, AN ELONGATED U-SHAPED VENTING CONTROL CHANNEL LODGED BETWEEN THE LEGS OF THE VENT SPLINE WITH THE EDGES OF THE LEGS OF THE U-SHAPED MEMBER ENGAGING THE SHOULDERS LONGITUDINALLY OF THE BODY AND SLIDABLE THEREALONG, THE BODY PORTION OF SAID U-SHAPED MEMBER BETWEEN THE LEGS THEREOF HAVING APERTURES THERETHROUGH, WHICH BY MOVEMENT OF THE VENTING CONTROL CHANNEL MAY BE SET INTO ANY DESIRED POSITION RELATIVE TO THE APERTURES THROUGH THE BODY OF THE SPLINE AND FOR CONTROL OF AIR MOVEMENT THROUGH THE VENTILATING SPLINE.