Abstract: A shearer cutting unit with double-speed rollers includes a motor driving unit, a motor driving unit, a gear transmission unit and a roller output unit. The motor driving unit includes a left cutting motor and a right cutting motor which are both arranged in a cutting unit case and connected with the roller output unit in a transmission way through the gear transmission unit. The roller output unit comprises a middle output shaft (3-1), a far-end output shaft, a middle support frame, a middle roller, a far-end support frame and a far-end roller. A cutting roller is separated into two coaxially-rotating parts, and the two rollers can rotate in different speeds.

Abstract: The invention relates to an earth working machine and to a method for wear-optimized operation of such an earth working machine. Provision is made in this context that machine parameters with which the earth working machine is operated are adapted, in consideration of material properties of the substrate to be worked, in such a way that favorable wear behavior exists for the earth working tools being used.

Abstract: A drive assembly for a mining machine. The drive assembly includes one-and-only-one sprocket and a housing coupled to the mining machine. The housing includes a shoe and at least partially receives the sprocket. The drive assembly also includes a motor and a drive shaft that couples the sprocket and the motor. The drive shaft rotates the sprocket and defines a longitudinal axis. The housing rotates relative to the mining machine about the longitudinal axis and in a face-to-gob direction.

Abstract: A longwall shearer or other machine with a gear case for transmitting rotational power from a drive to a driven member. The gear case comprises a drive, a driven member, at least one axle including at least one aperture formed therein to circulate cooling fluid through the axle, and a gear mounted to rotate on the axle and positioned to transmit power from the drive to the driven member.

Abstract: A pin-and-collet assembly, a longwall shearer comprising a ranging arm attached to a lifting bracket with such assembly, a method for the secure fastening of one piece to another, such as securely fastening the ranging arm to the lifting bracket of a longwall shearer using such assembly as a bushing, and a method for longwall mining of ore, such as trona, using such longwall shearer. This assembly is easy to install, does not have to be tightened during longwall operation of an ore panel, and is also demountable when it is time to stop the longwall mining operation and time to remove/replace the ranging arm for maintenance and/or when the end of the ore panel is reached.

Abstract: A drive assembly for a mining machine. The drive assembly includes one-and-only-one sprocket and a housing coupled to the mining machine. The housing includes a shoe and at least partially receives the sprocket. The drive assembly also includes a motor and a drive shaft that couples the sprocket and the motor. The drive shaft rotates the sprocket and defines a longitudinal axis. The housing rotates relative to the mining machine about the longitudinal axis and in a face-to-gob direction.

Abstract: A mining machine including a frame, a motor, a drive shaft having a first end and a distal end, a driven component coupled to the drive shaft at the distal end, and a connector assembly between the motor and the drive shaft. The connector assembly including a connection mechanism operable to drivingly connect the motor and the drive shaft, and an adjustment mechanism operable to adjust the connection mechanism between a connected condition, in which the connection mechanism drivingly connects the motor and the drive shaft, and a disconnected condition, in which the driving connection between the motor and the drive shaft is disengaged, the adjustment mechanism including an actuator pivotable about an axis between a connected position corresponding to the connected condition of the adjustment mechanism and a disconnected position corresponding to the disconnected condition of the adjustment mechanism, the actuator being axially fixed relative to the frame.

Abstract: A cutter head for a longwall shearer includes a drum, a vane, and a plurality of cutting bits. The drum includes a first end and a second end and defines an axis of rotation extending therebetween. The vane is connected to the drum and extends in a helical manner along at least a portion of the axis. The vane defines an edge surface extending along an outer perimeter of the vane. The cutting bits are secured to the vane edge surface. Each cutting bit includes a block and a bit coupled to the block. The block is secured to the edge surface and extends beyond the outer perimeter of the vane.

Abstract: A shearer mining machine generally includes a first chassis module, a second chassis module, one or more cleats, and means for securing each cleat on the first and second chassis modules. The first chassis module has a first mating surface and a first opening spaced from the first mating surface. The first opening is defined by a first wedge-shaped module wall positioned adjacent the first mating surface. The second chassis module has a second mating surface and a second opening spaced from the second mating surface. Each cleat includes a first projection, a second projection, and a bridge portion extending between the first projection and the second projection. The first projection is received by the first opening and includes a wedge-shaped cleat wall for engagement with the first wedge-shaped module wall. The means for securing apply a clamp force normal to the wedge-shaped cleat wall.

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 longwall shearer is positioned adjacent a face conveyor for transporting material that is cut from a mining face. The longwall shearer includes a chassis, an arm pivotably coupled to the chassis, a cutting drum for engaging the mining face, and a lump breaker for engaging material on the face conveyor. The chassis includes a first end and a second end, and the chassis is movable in at least a first direction that is generally parallel to the mining face. The cutting drum is rotatably supported on the arm. The lump breaker is pivotably coupled to the chassis about an axis, and the lump breaker includes at least one tooth for breaking apart the cut material.

Abstract: The present invention uses an Oscillating Disc Cutter (ODC) in a controlled manner to cut rock for assay purposes. The ODC (1) is mounted in an elongate guide frame typically in the form of an open box channel (2). The ODC is located on a carriage (3), the carriage itself mounted on guide rails (4) within the channel (2). The apparatus includes drive means operable to drive the carriage (3) in a rectilinear manner along the rails (4) such that the rails (4) define a cutting path. The ODC cuts a groove of controlled width and depth in a rock face, yielding rock chips that can be used for accurate assay of the face.

Abstract: A dust scrubber for a mining shearer machine is adapted to be mounted behind the rear surface of the shearer arm, on the opposite side of the arm to the mine surface being cut, so as to extract airborne particulates. The scrubber may be mounted to the shearer via a compensation mechanism such as a double hinge and link arrangement which maintains relatively static position and/or orientation of the scrubber despite the pivoting of the shearer arm in operation.

Abstract: A longwall shearer mining machine that is mounted on a rail generally includes a first chassis portion with a first cutting arm mounted thereto and a second chassis portion with a second cutting arm mounted thereto. Each of the first and the second chassis portions is slidably coupled to the rail. The first and second chassis portions are coupled at a pivot joint. The pivot joint allows each of the first and the second chassis portions to adjust its respective orientation with respect to a horizontal ground plane when the articulated shearer travels over a hump or a valley, thereby maintaining sufficient headroom.

Abstract: A longwall shearer mining machine that is mounted on a rail generally includes a first chassis portion with a first cutting arm mounted thereto and a second chassis portion with a second cutting arm mounted thereto. Each of the first and the second chassis portions is slidably coupled to the rail. The first and second chassis portions are coupled at a pivot joint. The pivot joint allows each of the first and the second chassis portions to adjust its respective orientation with respect to a horizontal ground plane when the articulated shearer travels over a hump or a valley, thereby maintaining sufficient headroom.

Abstract: A cooling system for the gear case in the ranging arm of a longwall shearer, the ranging arm including a plurality of single gears mounted in a row within an elongated housing. The cooling system includes a coolant injection system in each of the single gears, each coolant injection system including a longitudinal opening in the gear axle, and a coolant injection tube mounted inside the longitudinal opening. The coolant injection tube has a diameter smaller than the diameter of the longitudinal opening. A coolant supply line is connected to and in communication with the coolant injection tube, and a coolant outlet is connected to and in communication with the longitudinal opening adjacent the one end of the longitudinal opening, so that coolant leaving the end of the coolant injection tube travels back along the coolant injection tube and then out of the gear axle thereby removing heat from the single gear.

Abstract: A pin-and-collet assembly, a longwall shearer comprising a ranging arm attached to a lifting bracket with such assembly, a method for the secure fastening of one piece to another, such as securely fastening the ranging arm to the lifting bracket of a longwall shearer using such assembly as a bushing, and a method for longwall mining of ore, such as trona, using such longwall shearer. This assembly is easy to install, does not have to be tightened during longwall operation of an ore panel, and is also demountable when it is time to stop the longwall mining operation and time to remove/replace the ranging arm for maintenance and/or when the end of the ore panel is reached.

Abstract: Methods and systems for turning a cutting drum of a mining machine at a maintenance speed. One mining machine includes a cutting drum with a plurality of bits mounted on the drum and a cutting drum turning mechanism. The cutting drum turning mechanism includes a power source, a cutter motor, a switch, and a variable frequency drive. The state has a first and a second state. The first state electrically couples the power source and the cutter motor to operate the cutting drum at a cutting, and the second state electrically couples the variable frequency drive and the cutter motor to operate the cutting drum at a maintenance speed less than the cutting speed.

Abstract: A rack bar haulage system including a plurality of rack bars, each having spaced apart gear teeth extending between cheek sections at opposite sides of the rack bar. The haulage system also includes a clog including two spaced apart sidewalls, and openings through the sidewalls. One cheek section has a clog wall receiving cavity adapted to receive one of the clog sidewalls, the clog wall receiving cavity being defined by spaced apart cheek section flanges. The cheek section flanges each have an opening there through, and the cheek section flange openings are aligned with the clog sidewall openings. A pin is insertable through the sidewall openings and the openings in the cheek section flanges, and the spaced apart cheek sections are positioned so that the envelope formed by the gear teeth is at the same level on the rack bar as the pin for retaining the rack bar in the clog.

Abstract: A mining machine includes a cutting mechanism with an arm, and a substantial weight of more than a thousand pounds attached to the arm. The mining machine also includes a first disc cutter adapted to engage the material to be mined and mounted on a first disc cutter assembly for eccentrically driving the first disc cutter, the first disc cutter assembly being mounted within the substantial weight. The mining machine also includes at least a second disc cutter spaced apart from the first disc cutter assembly and adapted to engage the material to be mined, and mounted on a second disc cutter assembly for eccentrically driving the second disc cutter, the second disc cutter assembly being mounted within the substantial weight.

Abstract: A guide shoe for a shearer loader, in particular for a shearer-loader drive assembly, comprising at least one base wall, comprising a guide projection, on the base-wall side, for engaging under a rack drive of a rack drive arrangement, and comprising a guide surface for engaging behind the rack drive. To achieve shorter downtime periods in the case of repairs to the shearer-loader drive assembly due to wear, and in order to reduce their susceptibility to wear, the guide projection and the guide surface are realized on wear inserts that are movably and, preferably, replaceably fastened, or fastenable, to the guide shoe. Movement of the wear inserts could be limited by pivot limiting strips or inhibited by clamping strips.

Abstract: A rack bar haulage system forms part of a drive system for moving the mining machine along a conveyor including a plurality of conveyor pans. The pans are arranged end to end, and the rack bar haulage system includes a plurality of rack bars, each rack bar end including a pillar portion extending downwardly. One rack bar is adapted to be mounted adjacent an end of a line pan, and another rack bar is adapted to be mounted adjacent the adjacent end of the adjacent line pan. The haulage system also includes a chain-link, the chain-link surrounding and engaging the two adjacent pillar portions on the ends of the one rack bar and the adjacent other rack bar. The chain-link is adapted to extend over the adjacent ends of the line pans. The haulage system also includes a clog for receiving the rack bar, the clog including an extension that engages the chain-link and traps the chain link between the extension and the rack bar.

Abstract: A chain link assembly, a cable chain assembly and a mining system. The cable handler individual links may include an enclosed section for the fiber optic cable separate from other services for the machine. A flexible material or other structure may assemble the fiber optic cable in the cable handler in a manner in which it “snakes” about the centerline to provide ample slack in the fiber optic cable to, for example, prevent over tension.

Abstract: An underground boring machine includes a vehicle frame, a boom, and a boring cutter head. The boom includes a first end coupled to the vehicle frame and a second end. The boring cutter head includes a rotary joint, a first arm, and a second arm angularly spaced apart from the first arm. The rotary joint defines an axis of rotation and supports the boring cutter head for rotation with respect to the second end of the boom. The first arm includes a first end coupled to the rotary joint, a second end, and at least one disc cutter coupled to the first arm and oriented to engage the wall. The first arm extends from the first end toward the second end in a plane that is perpendicular to the axis of rotation. The second arm includes a first end coupled to the rotary joint, a second end, and at least one disc cutter coupled to the second arm and oriented to engage the wall. The second arm extends from the first end toward the second end in a plane that is perpendicular to the axis of rotation.

Abstract: A longwall shearer or other machine with a gear case for transmitting rotational power from a drive to a driven member. The gear case comprises a drive, a driven member, at least one axle including at least one aperture formed therein to circulate cooling fluid through the axle, and a gear mounted to rotate on the axle and positioned to transmit power from the drive to the driven member.

Abstract: A cooling system for the gear case in the ranging arm of a longwall shearer, the ranging arm including a plurality of single gears mounted in a row within an elongated housing. The cooling system includes a coolant injection system in each of the single gears, each coolant injection system including a longitudinal opening in the gear axle, and a coolant injection tube mounted inside the longitudinal opening. The coolant injection tube has a diameter smaller than the diameter of the longitudinal opening. A coolant supply line is connected to and in communication with the coolant injection tube, and a coolant outlet is connected to and in communication with the longitudinal opening adjacent the one end of the longitudinal opening, so that coolant leaving the end of the coolant injection tube travels back along the coolant injection tube and then out of the gear axle thereby removing heat from the single gear.

Abstract: A shearer loader for underground mining, the shear loader comprising a shearer loader body, at least one cutting drum fastened to a supporting arm joined to the loader body, a first drive motor for moving the shearer loader and a second drive motor for moving the cutting drums, a cooling water circuit for cooling the first and second drive motors, the cooling water circuit including an inlet and a return line, a spray system including at least one spray water circuit, the spray system including a feed line fluidly connecting a common water connection to the cutting drums, the spray system further including a valve in the feed line for switching the spray water circuits on and off, a control valve connected between the feed line of the spray water circuit and the return line of the cooling water circuit, the control valve allowing selective flow from the cooling water circuit to be directed to the cutting drums.

Abstract: A shearer-loader drive subassembly having a rotatably mounted drive sprocket, a transmission gear connected to the sprocket in a rotationally fixed manner, at least one releasable guide shoe provided for guiding the shearer loader on a rack arrangement, and a housing base plate, on which a bearing tube is supported and fastened in a rotationally fixed manner. The guide shoe is fastened by a pin which passes through the inner bore of the bearing tube and forms the pivot bearing for the guide shoe. A bearing sleeve rotatably supported on the bearing tube by a bearing may be arranged between the drive sprocket and the bearing tube, onto which bearing sleeve the drive sprocket may be pushed in a releasable manner.

Abstract: A coal plough for underground mining has a plough body that is guided along a plough guide. The plough body has at least one foot piece which receives a sliding skid. The sliding skid has at least one contact surface formed on its underside, which surface slides on a rail of the plough guide when the sliding skid is in its operating position. The sliding skid has first and second wear inlays on an underside which is arranged in the area of the highest load. The sliding skid can withstand high mechanical loads for a longer period of use.

Abstract: A method for extracting mineral deposits. First, a predetermined surface is contour mined in a mineral seam, such as a mountain, to provide an elongate active mining area and a highwall. Next, a sealable intake and return canopy is placed at substantially opposing ends of the mineral seam. A continuous miner then successively cuts a mineral seam in the elongate active mining area. Roof supports are advanced after each respective successive cut to support a roof of the elongate active mining area. After formation of an air seal and introduction of a conveyor in the elongate active mining area, either longwall or shortwall mining techniques may be used to cut a face of the mineral seam via a miner. Material cut from the face of the mineral seam is then discharged onto the conveyor. The intake and return canopies are then configured to allow ventilation of the active mining area by the introduction of air along the face of the mineral seam while the miner advances along the mineral seam.

Abstract: A mining machine is employed in a mechanized method for removing mineral from a reef in a rock face. The mining machine comprises a first cutting disc rotatably mounted on one side, a second cutting disc rotatably mounted on the machine, at a position off-set from the first disc and a cutting drum The first disc is adapted to remove a portion of the rock face as the machine is traversed along the face; and said drum is mounted upon an arm which is vertically repositionable to allow the cutting drum to remove rock from the roof and floor of the trench formed by the action of the cutting discs.

Abstract: This invention relates to a mining machine, and a mechanised method for removing mineral from a reef in a rock face. The mining machine comprising a first cutting disc (9a) rotatably mounted on one side, a second cutting disc (9b) rotatably mounted on the machine, at a position off-set from the first disc (9a), and a cutting drum (12). The first disc is adapted to remove a portion of the rock face as the machine is traversed along the face; and said drum (12) is mounted upon an arm (11) which is vertically repositionable to allow the cutting drum (12) to remove rock from the roof and floor of the trench formed by the action of the cutting discs (9a, 9b).

Abstract: The subject of the invention is the drive mechanism especially of the combined cutter loader in which the indirect toothed wheel (4) is placed between the toothed wheel (3) and the drive wheel mechanism (5) and is mounted on axis (8), which is mounted in hubs (8) and (9), in which eccentric bushes (11) and (12) are found, whereas hub (9) and the eccentric bush (11) placed in it are mounted in housing of holder (1), and hub (10) and the eccentric bush (12) mounted in the housing (2) of holder (1).

Abstract: Apparatus for measuring the degrees of roll of the body of a longwall shearing machine and providing signals proportional to the roll angle which are used to control drum cutting positions for controlling roof and floor horizons of a coal tunnel.

Abstract: A power train for driving a functional mechanism of a mining machine includes a sealing mechanism extendable across the space between drive and driven units in the power train and surrounding a drive shaft extending between the two units. The sealing mechanism includes a tubular seal carrier with one end portion which is sealable against an annular seal face on one of the units and an opposite end portion which is sealable against a sealing ring surface on the other of the units for sealed protection of a drive shaft connected between the units. A clamp is connectable between the one end of the carrier and the one unit to pull the carrier into sealing engagement with such unit while maintaining sealing contact with the other unit. When the clamp is released, the carrier is free to be moved into a retracted position freeing the space between the units to be used in removing either of the units from the power train.

Abstract: A method of steering a double-ended ranging drum mining machine includes the steps of positioning two previous cut roof followers spaced apart longitudinally of the machine, measuring machine tilt using a second means, estimating coal thickness using third means and generating algorithms therefrom whereby height differences between points on the current and previous cut roof can be calculated to control and steer the leading and trailing drums the algorithms being generated in such a manner that cumulative errors along or towards the face are minimized or eliminated.

Abstract: A drum cutter-loader mining machine equipped with an auxiliary debris crushing drum. The machine includes a cutter drum support arm and an auxiliary drum jib which are independently pivotable about a common pivot axis. The device further includes means for driving the auxiliary drum through a gearing communication between the auxiliary drum and the motor used for driving the cutting drum.

Abstract: In order to overcome problems associated with drum cutter-loader mining machines having a cutting drum mounted at one or both ends of the machine on pivotable support arms and further having cutting drum drive motors positioned outside of the machine body, there is provided a unique support arm system for adjusting the height of the cutting drums and their associated drive motors which neither reduces the debris pass-through cross-section of the machine bridge nor impairs the height adjustability of the cutting drums. The support arm system for each cutting drum and drive motor includes a first support arm section pivotally mounted at one end thereof to an end of the machine body and a second support arm section pivotally mounted to an opposite end of the first arm section. The second support arm section carries at least the cutting drum drive motor at one end thereof and the drive motor of each support arm is positionable inside the coal seam winning track.

Abstract: An improved drum-cutter mining machine design which transmits force exerted upon a drive wheel during translation of the mining machine along a rack structure to the machine. A protective housing encloses gears and a drive wheel in a manner such that feed forces exerted upon a drive wheel are transmitted through the housing to the mining machine.

Abstract: A power supply system for a drum-cutter mining machine utilized in longwall mining operations. Three-phase electrical power is supplied to a rectifier circuit positioned remote from the mining machine to rectify the three-phase electrical power. Rectified electrical power is supplied to the mining machine through cables, whereat the electrical power is inverted by inverters. Power transistors are coupled between the inverters and the respective motors of the mining machine. Positioning the rectifier remote from the mining machine allows the body of the mining machine to be of reduced dimensions.

Abstract: A drum-cutter mining machine for longwall mining operations which is adaptable for use upon longwall conveyor systems having rack structures positioned on either, or both, sides thereof. Drive motors are removably supported in a capstan housing of the mining machine, and positioned such that rotating shafts thereof extend toward either or both sides of the mining machine. Drive wheels coupled to the rotating shafts through reduction gears engage with the rack structures to allow translation of the machine therealong. When the mining machine is to be utilized on a longwall conveyor system having an alternate rack structure position, the drive motors may be removed, reoriented, reinserted into the capstan housing, and the drive wheels may be repositioned to allow operation of the mining machine.

Abstract: In a drum cutter-loader underground mining machine, wherein the drum is rotatably carried by an arm arranged adjacent to the coal face side of the machine. The arm is pivotally adjusted by a number of pressure cylinders and carried on an axis arranged between a machine body and a housing of a drive motor for the drum. The cylinders are carried by the machine body on a common axis with their piston rods connected to the housing on a common axis, the pivot axes of the arm, cylinders and the piston rod connections being parallelly arranged.

Abstract: The invention relates to ranging drum shearers having cutting drums driven by electric motors mounted on the respective ranging arms. A coal sizer is pivotably mounted on a shroud of the motor and is maintained at a constant disposition regardless of the position of the ranging arm. The coal sizer is maintained at a constant disposition through a control arm pivotally mounted to the pivot axis of the ranging arm and having a keyway containing a key on the axis of the coal sizer. The key and keyway provide for longitudinal movement of the coal sizer relative to the shearer body whereby on the pivotal movement of the ranging arm, the control arm remains stationary and the distance between the key and the axis of the shroud is maintained by the longitudinal adjustment of the coal sizer in the keyway.

Abstract: A drum cutter mining machine translatable along a longwall conveyor includes an auxiliary cutting drum for breaking up pieces of mineral carried by the longwall conveyor system. The auxiliary cutting drum is supported by a jib and an arm extension affixed in a fixed relationship with a support arm. The auxiliary cutting drum is positioned by the same actuator which pivotally positions the drum-cutter cutting drum at a desired cutting height at the mine roof and other times at the floor. Positioning of the cutting drum at the desired cutting height automatically positioned the auxiliary cutting drum.

Abstract: A shearer loader for underground mining operations including a duplex-input transmission coupled to the haulage box drive motor of the shearer loader. A first input of the duplex-input transmission is coupled to the haulage box office motor, and a second input of the duplex-input transmission is coupled to a drum-cutter drive motor of the shearer loader. During those times in which increased feed rates are required of the shearer loader, feed forces required for the increased feed rate is supplied by both the haulage box drive motor, and the drum-cutter drive motor.

Abstract: A double ended ranging drum shearer is provided with a shearer body and a pair of drums disposed at front and rear end portions of the shearer body to be movable up- and down-wardly. The shearer is further equipped with detectors for respectively detecting the travelling position of the shearer body, detecting the inclination of the shearer body at the travelled position, and detecting the heights of drums at the travelled position. These detectors are operatively connected to a controlling device which is connected to a drum height adjusting device. The controlling device operates and stores the drum heights necessary for keeping constant the working height of a mining face in a pit in accordance with output signals generated from the abovementioned detectors, and the drum height adjusting device is operated in response to an output transmitted from the controlling device representing the thus operated and stored data.

Abstract: A collet chuck including a chuck body, a collet which is fitted into the chuck body thereof, a fastening nut for chucking a cutting tool which is screwed into the main body of the chuck when the fastening nut is attachably connected to the collet and the collet is adapted to be reduced in diameter and wherein an external flange is provided around the collet, a pair of internal flanges are provided on the fastening nut, and fitting of these flanges into one another permits the collet and the fastening nut to be detachably connected to one another while a pair of notched portions opposite each are formed on the inward flanges of the fastening nut so that mounting and detaching can be easily performed.

Abstract: According to the applicant's invention a load detector is used, in which a load sensor and a vibration sensor are combined using an AND gate. A load signal from the load detector is used for the feedback control of the cutter drum height and double ranging drum cutter running speed, so that a person who is not skilled can operate the double ranging drum cutter while preventing overload acting on the cutter drum.

Abstract: A drift advancing or a partial-cut mining machine (1) comprises a cutting arm (11) being swivellable in a height direction around an axis (10). The front end of the cutting arm (11) is equipped with guides (26) transversely extending relative to the longitudinal axis (38) of the cutting arm (11) and having shiftably supported thereon a carrier (27) for the cutting heads (28, 29). The cutting heads (28, 29) are rotatably supported on the carrier (27) for rotation around vertical axes (46). The distance (a) between the axes of rotation (46) is, as measured in a transverse direction relative to the longitudinal axis (38) of the cutting arm, at most equal to half the width (b) of the drift face.

Abstract: A sectorial sprinkling device for coal mining includes, in the central portion of a cutting drum of a cutting machine, a plurality of concentric piping systems which are connected to water delivery means. An interior piping system is permanently connected to the picks of the shearing disc of the drum, but the other two piping systems open via radial ducts into sectorial chambers whose angular extent corresponds to that of the active sectors of the lateral face of the cutting drum, depending on whether the cutting drum is in the high or low cutting position.