Multiple ram adjustable mine roof support unit - has telescope spikes on floor and roof members and sloping shield member

摘要

The mine roof support arrangement with a roof member (14) and a floor member (3) interconnected by a sloping shield (7), has a swinging arm system (6) between the base of the shield (7) and the floor member. Parallel to the shield (7) is a main actuator cylinder (16) and an upper auxiliary cylinder (19) and a lower auxiliary cylinder (10). This arrangement allows the roof member to be advanced or retracted with respect to the floor member, as well as controlling the angle of the sloping shield (7). A pressure operated set of spikes (20) in both the floor and roof members can be employed to give a positive grip during the operating sequence.