BEADWALL
WINDOW OR WALL INSULATION COMPRISED OF PANELS OF GLASS OR PLASTIC BETWEEN WHICH BEADS OF STYROFOAM ARE BLOWN IN OR SUCKED OUT BY MEANS OF A FAN OR COMPRESSED AIR, PERMITTING THE PANELS TO OPEN OR CLOSE BY THERMOSTATIC OR MANUAL REGULATION
Expired · April 28, 1975 · 73050807 ·