Abstract: A drive unit for a mining machine such as a mining plow or conveyor drives a sprocket wheel of the chain thereof by an electric motor through a drive train having a turbocoupling and a transmission driven by the motor. A free-shifting clutch is provided in the case of overload to disconnect the load from the motor, the clutch reengaging upon standstill of the two clutch halves. Alternatively the turbine output of the fluid coupling is branched and is applied through one friction clutch directly to the input shaft of the transmission or through a second friction clutch to a parallel shaft connected by gearing to the transmission input shaft.

Abstract: A mining machine for excavating coal along a coal front of a seam in which a chain displaces excavating tools along an excavating stretch at a leading side across the coal face and a conveying stretch is provided rearwardly thereof, the stretch terminating in direction reversal stations with wheels at opposite ends of the stretches. A linear drive for at least one of the wheels can extend in a gallery alongside the mined cut. According to the invention, the excavating conveyer bottom is at an angular of 70.degree. to 130.degree. to the bottom of the conveying trough and the shafts of the wheels are inclined to the vertical forwardly and upwardly to include angles of 10.degree. to 45.degree..

Abstract: A mining machine especially for seam mining as in the mining of coal has a sensor for incipient sag of the plow pass of the continuously driven endless chain and a computer to which the sensor is connected and which controls the conveyor drive at the upstream end of the plow pass and the downstream end of a conveyor pass to reduce the speed of this drive until the plow pass is retensioned and any sag is accumulated at the conveyor pass. This arrangement eliminates problems with dislocation of the mining plow or of the conveyor flights as they are guided by guide devices onto the plow trough at the upstream end of the plow pass.

Abstract: A mining apparatus of the type in which a mining machine excavates a mining face, especially a coal face in a subterranean mining application, and has a plurality of emitters of electromagnetic waves of different character diverging toward receivers on the individual walking props. The walking props are provided with a control unit which, in response to leading and trailing zones of the respective magnetic beams and/or an overlap region of the two beams, causes the advance of the walking prop as the mining machine travels past it to follow the excavation of the mining face.

Abstract: A peripherally flexible arch for propping rock structure for mining tracks, tunnels or the like is comprised of a plurality of partially overlapped elongated segments, each of which has an end portion extended toward the rock structure, a bottom portion opposite to the end portion, and a lateral flange offset from the end portion laterally and in the direction toward the bottom portion. Clamping devices are arranged at the ends of the overlapping regions of the segments to clamp the segments to each other. The end portion of each lower segment is inserted into a groove formed between the end portion and the flange portion of each upper segment at the side of this segment facing away from the rock structure. Each clamping device has a hook engaged in a groove formed between the end portion and the flange of the upper segment at the side of this segment facing toward the rock structure.

Abstract: A method of and an arrangement for loosening, loading and transporting of stratified minerals includes a single continuously rotating and forceably guided pulling organ, a plurality of loosening elements integrated in the pulling organ in its working run extending in a longitudinal direction of a longwall, and a plurality of transporting elements also integrated in the same single pulling organ at its transporting run located behind the working run at a back filling side, wherein the loosening elements perform loosening and loading functions, whereas the transporting elements perform the transporting functions in an opposite longitudinal direction of the longwall.

Abstract: An arrangement for supplying consumers, particularly mobile consumers, with pressure fluids such as pressure air or pressure liquid, particularly in underground excavations, has a composite rail track for guiding a pressure fluid, a plurality of nipples arranged at a predetermined distance from one another in the longitudinal direction of the rail track, and at least one fluid withdrawing unit which cooperates with the nipples to open the latter and has a length selected with respect to the distance between two neighboring nipples so that one nipple is always located in the effective region of the withdrawing unit to be opened by the latter.

Abstract: A rock anchoring arrangement for use in tunnel and mine constructions comprises an elongated anchoring rod insertable in a bore formed in a rock formation, and a supporting plate arranged in contact with the rock formation at the open end of the bore. The anchoring rod includes a leading end portion fixable at the bottom of the bore, a trailing end portion fixable at the open end of the bore, and a smooth intermediate portion of a cross-sectional area smaller than those of the trailing end portion and the leading end portion. The anchoring rod is fixable by an adhesive within the bore at the leading end portion and at the trailing end portion whereas the intermediate portion is surrounded by an adhesive-repellent material to prevent the sticking thereof to the adhesive.

Abstract: An hydraulic prop utilized for barricades in blasting operations that affords simplified mounting and dismantling and will have minimal functional inefficiency if deformed by the impact of rocks; and it can be made out of unworked pipe of minimal standards. Two specific guide regions disposed on the piston are spaced large enough from each other that comparatively wide tolerances can be achieved between the piston and the cylinder.

Abstract: A wall element for an underground gallery has a W-shaped member which is symmetrical relative to its y-axis and has an axis of gravity coinciding with its x-axis and lying at approximately the center of its side, wherein the thickness of its lateral flange portions, base portions and connecting web portions are selected so that, in relation to used weight per meter, the W-shaped member has a maximum possible moment of resistance relative to the x-axis and a maximum possible bending load capacity in the plastic deformation range, and the W-shaped member has such a profile and such thicknesses of these portions that it has at least approximately equal bending load capacities in the plastic deformation region in two opposite directions along the y-axis.

Abstract: An arrangement for erecting a columnar supporting element of a hardenable flowable material, for a roof of an underground excavation, has a hollow casing for filling with a hardenable flowable material and is composed of two telescopable casing portions each composed of two open-end semi-circular sections, an element for holding the upper casing portion in contact with the roof of an underground excavation and arranged adjacent to the casing, and elements for connecting the semi-circular sections of at least the lower prop casing portions with one another so as to be pivotable about a longitudinal pivot axis which is parallel to the longitudinal axis of the prop casing, and locking the same with one another.