Patent ID: 6032986
Filing Date: 2000-03-07
Classification: E05C,E21F,Y10S,Y10T

Abstract:
A door system for closing a doorway in a mine stopping, said door system comprising:a door hinged adjacent the doorway for swinging relative to the stopping between a closed position and an open position swung outwardly away from the stopping,a keeper mounted in fixed position relative to the doorway, andlatch means cooperable with the keeper for latching the door in its closed position, said latch means having a detent portion, said latch means being operable to move the detent portion between a latching position in which the detent portion engages the keeper for latching the door closed, and an unlatching position in which the detent portion is disengaged from the keeper for allowing the door to be opened,said latch means comprising a quadrilateral linkage constructed and configured so that it operates to move said detent portion along a path defined at least in part by an arc centered on a point spaced away from the door on a side of the door opposite from the detent portion whereby the detent portion of the latching means is adapted to remain in substantial engagement with the keeper to maintain the door closed in the event the keeper moves relative to the door, as in a mine convergence.