Roof support unit for mines - has waste shield of roof cap connected to base plate by pantograph linkage

摘要

The roof support unit for mines inlcudes a base plate (10) with a number of props. The props support a roof cap which has a shield (14) suspended on its rear and for screening the face against waste. The shield is joined by a linkage to the base plate. The linkage consists of a number or rods (16, 17, 18) which are pivotably joined together to form a pantograph. The stationary pivot point of the pantograph is positioned on the base plate (10) and its first movable point is positioned on he axis of a pivot joint between te shield (14) and the roof cap. The second movable point (24) of the pantograph type assembly is guided along a vertical sliding guide track, fixed relative to the lower pivot (20).