Mine shield support with roofbar - roofbar forepoled off telescopic powered beam with joint on waste shield

摘要

Mine shield support composed of floor bar (1), vertically pivotal waste shield (2), a hinge mounted supporting prop (4) and a forepoling bar (3) with individual movement. In effect the roof is supported exclusively by the bar (3) which is a one piece structure presenting identical supporting surface in each forepoled setting and hinged to a telescopic beam (7) which is carried in a box joint (6) and controlled by a hydraulic ram (8). The box is pivoted on the waste shield and reaches forward towards the face and is positioned parallel or slightly inclined with respect to the floor bar at all support levels with the assistance of a roofbar guide or other means.