Patent ID: 7182687

Claim:
A mine ventilation structure incorporated at the intersection of first and second intersecting passages in a mine, the passages constituting first and second airways for flow of air for mine ventilation, the intersection having a floor and a roof and the airways each having a floor, ribs at the sides and a roof with an upstream and a downstream mouth at the intersection, said structure comprising a tunnel-forming overcast at the intersection comprising a pair of side walls each walling off at least a portion of a respective mouth of the first airway and a deck spanning the side walls and connected thereto, the space between the side walls and below the deck constituting a tunnel for flow of air from the upstream to the downstream mouth of the second airway, the roof above the deck and the roof of the first airway adjacent the ends of the deck being formed to provide an above-the-deck passage establishing communication for flow of air through the first airway over the deck from one side of the overcast to the other, and an air deflector in the first airway adjacent the overcast, the air deflector comprising an inclined wall, a lower edge of the inclined wall being spaced from the overcast in the first airway, the inclined wall sloping up from its lower edge toward the above-the-deck passage.