A mine door of the present invention is adapted for installation in a mine passageway
and includes a leaf adapted for swinging between a closed position and an open
position. The leaf may be mounted in a frame, and a stopping wall may surround
the frame. When closed, the leaf is subject to a differential in air pressure involving
higher pressure on one of the faces of the leaf than on the other of the faces
of the leaf. The leaf, the frame, or the stopping has an opening therein for passage
of air therethrough from adjacent the one of the faces of the leaf to adjacent
the other of the faces to more nearly equalize the pressure on the faces and thereby
facilitate opening the leaf.