Abstract: Method of automatically producing a defined face opening, in underground coal mining, during longwall mining operations having a face conveyor, a disk shearer loader and a hydraulic shield support. Via at least one inclination sensor on the top canopy of the shield support frame, the inclination of the top canopy relative to the horizontal, in the direction of mining or extraction of the disk shearer loader, is determined to provide angles of the course of an overlying stratum at the shield support frame. A stepping path length of each shield support frame is detected, and therefrom a cutting depth of the disk shearer loader during an extraction run is determined. A cutting height of the disk shearer loader is detected by means of sensors disposed thereon, and a cutting height of the disk shearer loader is adjusted in alignment with the angle of the course of the overlying stratum to produce the defined face opening.

Abstract: A method for automated production of a defined face opening in longwall mining operations in underground coal mining, comprising a face conveyor, disk shearer as extraction machine, and hydraulic shield support frame. At least one radar sensor is provided on a main body of the disk shearer. A distance between an upper edge of the main body and an underside of a top canopy of the shield support frame below which the main body travels during extraction work is measured, and is input into a computer as an actual value for a passage height of the disk shearer below the shield support frame. This actual value is compared with a target value and, if a deviation is determined, control commands are generated for adapting a cutting height of at least one of two cutting disks of the disk shearer.

Abstract: A method of setting an automatic level control of a plow in longwall mining operations. By means of a boom control mechanism, a control angle for setting motion of the plow, which is guided on a face conveyor, in an exploitation direction as a climbing, plunging or neutral motion is set. For each plow stroke, a cutting depth and the control angle, derived as a differential angle between inclinations of the face conveyor and of a top canopy of a shield support frame are determined. In a calculating unit, a face height change per plow stroke is calculated therefrom and a face height, as a projected height, is associated with each face position of the face conveyor. When a shield support frame that trails behind the plow in terms of a time delay reaches a respective face position, an actual height of the face is calculated and compared with the store projected height.

Abstract: Longwall equipment for mechanical extraction, especially in underground coal mining, including a face conveyor disposed along a longwall face, a disc shearer loader that includes a machine body that rests, and is guided, upon the face conveyor and includes two shearing discs pivotably disposed thereon, with the machine body extending over the face conveyor and forming a portal that prescribes a maximum loading cross-section of the face conveyor, a lifting mechanism mounted on the machine body for guiding it on the face conveyor in a vertically adjustable manner and for variably adjusting the portal cross-section, a drive element height-adjustably disposed on the machine body and engaging an abutment fixedly disposed on the face conveyor, and shield support units that include top canopies that project toward the disc shearer loader.

Abstract: A method for controlling a longwall mining operation, including a face conveyor, at least one extraction machine, and a hydraulic shield support, in underground coal mining. Using inclination sensors disposed on at least three of the four main components of each shield support frame, such as floor skid, gob shield, support connection rods, and gob-side region of the top canopy, the inclination of the shield components relative to horizontal is ascertained in the direction of step. In a computer, the ascertained inclination data is compared with base data stored in the computer that defines the geometrical orientation of the components and their movement during stepping. From the comparison, a respective height of the shield support frame, at the forward end of the top canopy, is calculated as a measure for the face opening.

Abstract: A method for controlling the extraction capacity of longwall operations in underground coal mining, including ascertaining the respective demand of the longwall operations, for air-technology and climate-technology resources, as influencing variables for a projected delivery quantity on the basis of data applicable to equipment of the longwall operations and to mineral deposit parameters, and storing the ascertained influencing variables in a computer as target data. Actual data for a raw coal delivery quantity, for air flowing through, for the supplied cooling capacity, and for the exhaust gas during running operation is detected and conveyed to the computer. if an increased demand for resources is recognized, coverage is initiated via a changeover of excess resources available at other longwall operations or if a reduced demand for resources is recognized, excess resources are rerouted to other longwall operations experiencing corresponding demand deficiencies.

Abstract: An electrical circuit comprising a power supply, a load and an incendive arc prevention means comprising a monitoring means and an isolation means, in which the monitoring means monitors the electrical circuit by means of a reactor means, in which if a short circuit with the potential to cause an incendive arc occurs in the electrical circuit the reaction of the reactor means is detected by the monitoring means and the isolation means fully or partially isolates the power supply from said short circuit, such that an incendive arc cannot occur, in which if an event with a current and/or voltage pattern which is characteristic of a propagating non-incendive arc occurs in the electrical circuit between the power supply and the load, the reaction of the reactor means is detected by the monitoring means, and the isolation means fully or partially isolates the power supply from said event, such that an incendive arc cannot occur.

Abstract: A method for automatically producing a defined face opening in a longwall mining operation in underground coal mining, using a face conveyor, at least one plow, as an extraction machine, guided on the face conveyor, and respective hydraulic shield support frames having, as main components, a floor skid arrangement, a gob shield, a top canopy and support connection rods. Inclination sensors are disposed on at least three of the floor skid arrangements, the gob shield, the support connection rods and a gob-side region of the top canopy. From the sensors, an inclination relative to a horizontal is ascertained.

Abstract: A method for controlling longwall mining operations, having a face conveyor, at least one extraction machine, and a hydraulic shield support, in underground coal mining. At least one sensor is disposed on the shield support frames for acquiring solid-borne noise data generated by the engagement of the extraction machine in coal and/or country rock. A cut of the extraction machine into the country rock is determined in a downstream computer on the basis of recorded vibration data that corresponds to the generated solid-borne noise.

Abstract: A method for automatically producing a defined face opening in a longwall mining operation, in underground coal mining, having a face conveyor, at least one extraction machine and hydraulic shield support frames. Inclination sensors are disposed on at least three of the four main components of each shield support frame, such as floor skid, gob shield, support connection rods and gob-side area of the top canopy. From ascertained inclination data, by comparison with base data defining a geometrical orientation of the components and a movement thereof during stepping, a respective shield height of the shield support frames perpendicular to a bed thereof is calculated. From further sensors on the extraction machine, a cutting height thereof is acquired as a face opening.

Abstract: A method for maintaining, in a controlled manner, a top canopy/coal-face distance expedient for rock mechanics, in longwall mining operations in underground coal mining, using a face conveyor, at least one extraction machine, and a hydraulic shield support frame. Inclination sensors are disposed on at least three of the four main components of the shield support frame, including floor skid, gob shield, support connection rods and gob-side area of the top canopy. An inclination of the top canopy and floor skid are ascertained via the sensors. From the ascertained inclination data, in a computer, the effects on a top canopy/coal face distance are determined when changes in an angle of inclination of the top canopy occur. An automatic adjustment of decisive cycle parameters of the shield support frame are carried out, wherein the work cycle comprises retraction, advancement and setting processes.

Abstract: A method of controlling conveyance of the debris, extracted by working machines in underground mining operations, via conveyors and bunker units. The lowest available conveying capacity of the conveyors and buffer capacity of the bunker units are determined based on continuously detected actual data and are compared in a computer-aided control unit to at least one of current actual extraction output, anticipated target extraction output, and scheduled output extrapolated from past actual data. Upon detection of deviations, the control unit automatically effects a balancing of capacities between the conveyors and bunker units connected at an output side of each individual different working machine, taking into consideration their maximum conveying capacity and buffer capacity respectively, and/or controls the extraction output of the working machines taking into consideration respectively available conveying capacity of downstream conveyors and buffer capacity of the bunker units.

Abstract: An electrical circuit comprising a power supply, a load and an incendive arc prevention means comprising a monitoring means and an isolation means, in which the monitoring means monitors the electrical circuit by means of a reactor means, in which if a short circuit with the potential to cause an incendive arc occurs in the electrical circuit the reaction of the reactor means is detected by the monitoring means and the isolation means fully or partially isolates the power supply from said short circuit, such that an incendive arc cannot occur, in which if an event with a current and/or voltage pattern which is characteristic of a propagating non-incendive arc occurs in the electrical circuit between the power supply and the load, the reaction of the reactor means is detected by the monitoring means, and the isolation means fully or partially isolates the power supply from said event, such that an incendive arc cannot occur.

Abstract: A roadway support (1) is introduced in parallel to the face advancement of a gallery(1) by means of a selective cut heading machine (2) by providing lagging mats (18, 19) in the form of rolled mats (20, 21) downstream of the cutting tool (3) of the selective cut heading machine (2) in two transverse planes (14, 15) that are arranged behind one another in the longitudinal heading direction in circumferential offset relationship. The lagging mats (18, 19) are then unrolled simultaneously to the face advancement in the longitudinal heading direction so as to overlap laterally and are instantly aligned upon the rock. Once the lagging mats (18, 19) have been entirely unrolled, the working steps are successively repeated in accordance with the length of the face advancement with new lagging mats (18, 19) that adjoin the lagging mats (18, 19) previously laid. The roadway support (7) is introduced at a distance to the cutting tool (3) while fixing the lagging mats (18, 19).

Abstract: A device for intrinsically safe, redundant current-voltage supply for electric loads in an explosion-proof area. The device includes at least two supply circuits for making available the current/voltage supply and a protective device for intrinsically safe current and voltage limitation of the power supplied by the supply circuits to the load in the explosion-proof area. The supply circuits are connected in parallel to one another and the protective device has at least one resistive current limiting device for intrinsic safety in parallel-active supply circuits.

Abstract: The present invention relates to a device for intrinsically safe, redundant current-voltage supply for electric loads in an explosion-proof area. In a device according to the invention there are at least two supply circuits for making available the current/voltage supply and a protective device for intrinsically safe current and voltage limitation of the power supplied by the supply circuits to the load in the explosion-proof area. According to the invention, the device is characterized in that the supply circuits are connected in parallel to one another and that the protective device has at least one resistive current limiting device for intrinsic safety in parallel-active supply circuits.

Abstract: Low voltage logic circuitry is used to permit an entire subsystem of an industrial controller to be placed within a hazardous environment to receive a high speed serial link and undertake the control of multiple control points without expensive and awkward long cable runs and electrically isolating circuits for each cable run. Energy and bandwidth limiting on the high speed link allows power levels commensurate with high data rates yet intrinsic safety of the media allowing it to freely pass in and out of the hazardous area. A mixture of intrinsically safe and non-intrinsically safe equipment on the same logical rack is allowed through a bus isolator providing isolated data communication in backplane fashion between modules while wholly isolating power transmission along the backplane.