Safety construction work for closing off of an underground extraction working

摘要

The dike fill (6) is established across the upper development road (2) to close it off, and a lock chamber (7) is incorporated in it having two doors (8-11) to seal the chamber. Between the two doors is an inner space (14), to which a fill duct is connected, and the space is then filled, the doors acting as formwork. The doors are of double-wing, triangular type and, when closed, meet along the centre line of the inner space. A third pair of wing doors (12,13) are hung on the working side of the dike and, when closed, meet on the centre line of the inner space, but outside the dike. USE/ADVANTAGE - For underground mines etc.,with simple and safe sealing off.