Air perimeter seal for opening

Abstract

A seal disposed about the periphery of an opening such as a warehouse door includes an inflatable head bag and a pair of facing inflatable side bags. The head and side bags are each comprised of a plurality of serially coupled, elongated, aligned pleated sections which are separated by apertured baffles for regulating air flow between adjacent pleated sections. A source of air under pressure such as a blower directs air into an upper head bag which, in turn, directs the air flow into the facing side bags via respective duct arrangements coupling the head bag to the side bags. Under pressure, the head and side bags expand toward the center of the opening to enclose in a sealed manner an object such as a loading vehicle positioned within the opening. Disposed within and along the width of each of the side bags are a plurality of spaced horizontal ropes or straps which are coupled at a first end thereof via an alignment tube to the nose edge of the end, or distal, pleated bag section, and at a second end thereof to vertically movable weights which bias the side bags to the retracted or open positon when air under pressure is no longer provided to the side bags. A plurality of spaced vertical retraction straps in the head bag are wrapped around a spring-biased roller tube positioned in an upper portion of a support frame and extending across the opening for rolling the head bag up in a retracted position when air under pressure is no longer delivered to the perimeter seal.