Abstract: A mining system comprises a laterally deflectable segmented conveyor extending longitudinally along a longitudinal face from which material is to be cut, a mining machine displaceable longitudinally along the conveyor and engageable with the face to cut material therefrom and deposit in the conveyor, and a longitudinal succession of support frames each having a respective actuator connected to a respective segment of the conveyor and each also having a respective a respective retractile roof-engaging flap. The process of this invention comprises bracing the frames and conveyor in a safety zone immediately adjacent the mining machine against the roof with their flaps retracted. The machine is advanced in the safety zone while cutting the face in the safety zone, and the flaps of the frames in a zone immediately downstream of the safety zone are sequentially retracted and the flaps of the frames in a zone upstream of the safety zone are sequentially advanced.

Abstract: A method in underground coal mining for separating the upper coal of the seam from the roof during the advancement of the upper sliding cap of a support frame, wherein the front edge of the cap is forced in a plane of the cap between the upper coal to be separated and the rock from which the coal is to be separated. During the advancement of the sliding cap, the sliding cap is alternatingly moved backwardly and forwardly, so that the from edge of the sliding cap separates the upper coal during its forward movement. Alternatively or additionally, when the front edge of the sliding cap contacts the upper coal, alternatingly higher and lower pressure can be admitted to the sliding cap in order to obtain a shaking effect. In this combined method, the sliding cap is advanced, the shaking procedure is carried out as the front edge contacts the upper coal, and the sliding cap is subsequently moved backwardly. The cycle is then repeated several times.

Abstract: A mine roof support for an underground mine gallery comprises a sole plate adapted to rest on the floor of the mine gallery. The sole plate is connected by links to the region of the lower end of a rear shield, and the upper end of the latter is connected by pivot means to a roof shield, between opposite ends of the latter, in such a manner that a portion of the roof shield between the front end thereof and the pivoted means is considerably longer than the portion of the roof shield between the pivot means and the rear end of the roof shield. At least one extensible and collapsible prop extends between the sole plate and the portion of the roof shield which is located forwardly of the pivot means and at least one additional prop extends between the sole plate and the rear shield, so that the roof shield may be pressed against the roof of the mine gallery and be shifted relative to the mine face.

Abstract: A mine roof support for underground excavations includes a support adapted to engage the floor of the underground excavation, and a movable roof shield which engages the roof of the underground excavation. A movable rear shield is mounted on the support and is pivotally connected with the roof shield for relative movement thereto about a pivot axis. A pit prop arrangement is provided intermediate the shields and the support for moving the shields relative to each other about the pivot axis between a plurality of inclined positions in which the rear shield is inclined at different angles of inclination relative to the roof shield. A pair of abutment members are respectively provided on the shields for limiting relative movement of the latter beyond a predetermined one of the inclined positions in which the shields are inclined at a predetermined angle of inclination relative to each other.

Abstract: An underground excavating system includes a conveyor device which is operative for conveying material away from a mine face, and an excavation roof support device which is operative for supporting the roof of the excavation. A hydraulic cylinder-piston unit is operatively connected to both of the devices and is operative for advancing one of the devices towards the mine face while the other of the devices remains stationary, and vice versa. A guiding arrangement is connected intermediate the control unit and the conveyor device and is operative for guiding the advancing device during its advance towards the mine face. The guiding arrangement includes a pair of elongated support members which are spaced apart of each other and which have one end region located closer to the mine face and another end region located further from the mine face. The guide arrangement further includes a pair of guide sleeve members one at each of the aforementioned end regions.