Air flow control means for air screen structures

Claim 1

IN AN AIR SCREEN STRUCTURE WHEREIN AIR MOVING MEANS ESTABLISHES A RECYCLING FLOW OF AIR THROUGH AIR DELIVERY MEANS AND AIR RETURN MEANS BOTH IN COMMUNICATION WITH A DOOR AREA AND POSITIONED ON OPPOSITE TOP AND BOTTOM SURFACE AREAS THEREOF TO ESTABLISH A DOWNWARD FLOW OF AIR, THE PROVISION OF DIRECTIONAL AIR FLOW CONTROL MEANS DEFINING SAID AIR DELIVERY MEANS, AND AIR MASS FLOW CONTROL MEANS DEFINING SAID RETURN MEANS, SAID AIR MASS FLOW CONTROL MEANS BEING IN THE FORM OF A GRATING WHICH INCLUDES A SERIES OF SPACED INVERTED MEMBERS HAVING DOWNWARDLY DIVERGENT SIDE PORTIONS DEPENDING FROM ASSOCIATION WITH TRANSVERSE GRATING MEMBERS, ONE OF SAID SIDE PORTIONS OF EACH INVERTED MEMBER BEING OF LESS LENGTH IN A DOWNWARDLY DIRECTION THAN THE OITHER, AND A MOVABLE SERIES OF SPACED BAFFLES EACH OF WHICH ARE INCLINED TO ASSUME THE INCLINATION OF A SHORTER SIDE PORTION OF AN INVERTED MEMBER AND CONSTITUTE A DOWNWARD EXTENSION OF THE SAME UPON MOVEMENT INTO ASSOCIATION THEREWITH, SAID BAFFLES COOPERATING WITH EACH OF THE OTHER OF SAID SIDE PORTIONS TO DEFINE THEREBETWEEN A GROOVE-LIKE AIR TRAPPING AREA AND RESTRICTED THROATS TO CONTROL THE MASS OF AIR FLOWING DOWNWARDLY THROUGH SAID GRATING.