Adjustable grille

Claim 1

IN AND ADJUSTABLE GRILLE, THE COMBINATION OF, A FRAME, A SET OF PARALLEL VANES MOUNTED IN SAID FRAME FOR ANGULAR ADJUSTMENT ABOUT AXES EXTENDING LONGITUDINALLY OF THE VANES, A SET OF PARALLEL FINS SPACED APART LONGITUDINALLY OF SAID VANES AND MOUNTED IN SAID FRAME FOR ANGULAR ADJUSTMENT ABOUT LONGITUDINAL AXES PERPENDICULAR TO SAID VANE AXES, EACH OF SAID FINS HAVING A SERIES OF NOTCHES SPACED ALONG ONE EDGE AND EACH DEFINED BY SIDE WALLS SPACED APART LONGITUDINALLY OF THE FIN AND STRADDLING ONE EDGE PORTION OF ONE OF SAID VANES, AND EACH OF SAID VANES HAVING A PLURALITY OF EQUALLY SPACED CIRCULAR HOLES THEREIN INTERMEDIATE THE EDGES OF THE VANE AND LYING IN THE PLANES OF THE RESPECTIVE FINS ALONG THE AXES OF THE FINS, AND A LUG ON ONE SIDE WALL OF EACH NOTCH EXTENDING ALONG THE AXIS OF THE FIN AND PROJECTING INTO THE ALINED HOLE IN THE VANE DISPOSED IN THE NOTCH THEREBY TO RETAIN THE VANE AGAINST EDGEWISE DISPLACEMENT OUT OF THE NOTCH, SAID LUGS BEING OF SHORTER CROSS-SECTIONAL LENGTH THAN THE DIAMETER OF THE HOLES WHEREBY THE VANES ARE FREE TO ROCK RELATIVE TO THE LUGS, AND SAID SIDE WALLS DIVERGING BOTH OUTWARDLY FROM THE LUGS TOWARD THE OPEN END OF THE NOTCH AND INWARDLY FROM THE LUGS TOWARD THE CLOSED END OF THE NOTCH FROM A SPACING APPROXIMATELY THE SAME AS THE VANE THICKNESS TO A VANES WITHIN THE NOTCHES.