Abstract: A cutting head for hard rock mining applications is disclosed. The cutting head may have a base member. The base member may have a rotational axis and may include a center bore extending along the rotational axis. The cutting head may also have a drive bushing disposed within the center bore. The drive bushing may be configured to transmit torque from a driving device to the base member. The cutting may further have a plurality of annular tool supports. Each of the plurality of annular tool supports may be concentrically disposed about the rotational axis in a releasable manner. In addition, the cutting head may have a plurality of cutting bit carriers attached to each of the plurality of annular tool supports. Each of the plurality of cutting bit carriers may be configured to rotatably support a cutting bit.

Abstract: A method of controlling a shearer is disclosed. The shearer may be configured to travel along a longwall face to extract material with a first cutting drum and a second cutting drum. The method may include setting a first cutting profile including a plurality of desired positions (Di) to be approached by the first cutting drum in a first travel direction (E). Further, the method may include determining a plurality of actual advancing vectors (vi) indicating a change of a position of the shearer resulting from advancing the shearer towards the longwall face. The method may also include determining a plurality of shearer orientations (Oi) along the longwall face. In addition, the method may include generating a second cutting profile to be approached by at least one of the first cutting drum and the second cutting drum in a second travel direction (F) of the shearer.

Abstract: A milling device is disclosed. The milling device may have a shaft. The shaft may have a shaft axis (A). The milling device may also have a spindle drum rotatably mounted relative to the shaft axis (A) and rotatable about a spindle drum axis (B) coaxial to the shaft axis (A). Further, the milling device may have a plurality of tool spindles rotatably mounted in the spindle drum and rotatable about tool spindle axes (D). Each tool spindle axis (D) may be parallely arranged and spaced apart from the shaft axis (A) and may have a same distance to the shaft axis (A). The milling machine may also have a plurality of machining tools carried by the tool spindles. At least two of the plurality of machining tools may be positioned displaced from one another in a direction of the shaft axis (A).

Abstract: A drive connection is disclosed. The drive connection may be configured to be interconnected between a main driving unit and a main gear unit of a driving device configured to drive a chain of a conveyor of a longwall device. The drive connection may have a housing configured to be connected to the main driving unit and to the main gear unit. The drive connection may also have a drive shaft disposed within the housing and configured to transmit torque from the main driving unit to the main gear unit. In addition, the drive connection may have a chain tensioning apparatus disposed within the housing. The chain tensioning apparatus may have a worm drive interacting with the drive shaft. The chain tensioning apparatus may be configured to drive the drive shaft for tensioning the chain of the conveyor when the main driving unit is in a non-operative state.

Abstract: The present disclosure relates to a scraper for chain scraper conveyors, particularly twin chain scraper conveyors. The scraper may comprise a one-piece scraper bridge including two side scraper wings connected by a head web, a retaining bracket insertable from an underneath side of the scraper bridge into an insert recess, and a locking device. The retaining bracket may be insertable for detachably locking the scraper on a chain link of a scraper chain. The retaining bracket may engage with grooves on either side of the insert recess in an assembled state. The scraper may further include a locking device for securing the assembly state of the retaining bracket in the insert recess, wherein the retaining bracket may be displaceable in the associated insert recess parallel to the head web on one of the scraper wings into a locking position and having at least one retaining cam.

Abstract: A feed system, rack bar and drive sprocket for moving an underground winning machine having a travel drive with drive sprocket having symmetrically profiled teeth, and rack bars with a plurality of rack teeth being arranged between a supporting strip and a guide strip of the rack bar. The tooth flanks of the teeth are inclined in the direction of movement and diverge towards the tooth tip for the interaction with tooth surfaces of teeth of drive sprocket. In order to improve the interaction between the teeth and produce less wear, the two tooth flanks of each rack tooth are concavely arched and form a trough between guide strip and supporting strip transversely to the direction of movement, with the trough rising towards the tooth tip, and the two tooth surfaces of each drive sprocket tooth is convexly arched and forms a crown transversely to the direction of movement.

Abstract: A longwall installation unit is disclosed. The longwall installation unit may form a longwall installation assembly together with other longwall installation units of the same kind. The longwall installation assembly may extend along the longwall face in a longwall mine. The longwall mine may have a compressor device. The longwall installation unit may have a dilution gas nozzle configured to be fluidly connected to the compressor device.

Abstract: A coarse crusher for use at both face ends of a face conveyor in an underground mine is disclosed. The coarse crusher may have a pan module with a strand segment for guiding an endless conveying means. The strand segment may be delimited by a first pan outer longitudinal side and a second pan outer longitudinal side which lies opposite the first pan outer longitudinal side. The first pan outer longitudinal side and the second pan outer longitudinal side may have a plurality of first pan fastening apparatuses. The coarse crusher may further have a base-frame module fastened releasably via the corresponding first pan fastening apparatuses to one of the first pan outer longitudinal side and the second pan outer longitudinal side. The coarse crusher may also have a support-arm module fastened releasably to the base-frame module.

Abstract: A chain wheel for driving or diverting a conveyor of an apron conveyor including transport plates is disclosed. The transport plates may be releasably connectable via a chain connecting parts to the conveyor chain. The chain wheel may have a chain wheel body including a lateral face. The chain wheel may also have teeth arranged peripherally offset over the lateral face. In addition, the chain wheel may have bearing faces. The bearing faces may be arranged peripherally offset over the lateral face between two adjacently situated teeth. The bearing faces may also be configured to support the chain connecting parts.

Abstract: A mining apparatus includes two tool drums, which are arranged rotatably side by side in twin arrangement on a drum carrier and which are respectively provided with a plurality of tool carriers which support cutting tools arranged over the periphery of the tool drums and which can be rotatingly driven and the shaft axes of which run substantially transversely to the drum axle. The shaft axes of the tool carriers of the first tool drum span a first conical surface about the drum axis and the shaft axes of the tool carriers of the second tool drum span a second conical surface about the drum axis, where the conical surfaces are open to opposite sides and are preferably oriented such that they are mutually inclined in an O-arrangement.

Abstract: A hydraulic switching mechanism for the mobile hydraulics of, for example, hydraulic excavators, with a valve block, with electrohydraulically activatable valve units for controlling the movement of a working cylinder whose cylinder chambers can be selectively connected to a pump connection for hydraulic fluid, to a tank connection or to one another, and with pre-control valves for activating the valve units, wherein the hydraulic switching mechanism, by means of separate tank valve units and pump valve units, and also a suitable pre-control system, makes it possible to achieve a directional control valve function and a directly controlled and superimposed pre-controlled lowering braking function, a maximum pressure safeguarding of the cylinders and a proportional throttle valve function for the controlled displacement under negative load forces in the direction of movement and braking in an emergency; and mobile hydraulic machines having such a hydraulic switching mechanism and also to valve units therefor.

Abstract: An intrinsically safe connection unit with a network interface for intrinsically safe appliances in explosion-risk areas, having a housing, a voltage supply connection, plug connection for connecting an intrinsically safe appliance via a transmission cable, and a decoupling circuit. For allowing even a multiplicity of network subscribers to be connected in the explosion-risk area with less wiring complexity, a plurality of plug connections of the same type are provided as network interface, each being preceded by a separate decoupling circuit, and the voltage supply connection builds a central feed connection with separate supply cores for each plug connection each having at least two plug contacts for data communication and at least two plug contacts for supplying power to the connectable appliances via the transmission cable. The invention relates also to a Controller and a network interface for use therewith.

Abstract: A replaceable guide piece (10) for an extraction or coal plough (100) is provided. The replaceable guide piece (10) includes a generally U-shaped guide piece body (12) configured to be inserted into a guide claw (14) of the plough (100). A single recess (22) is formed in a central portion of a guide piece body (12) to extend at an angle (?) from an upper side of guide piece body (12) to a side surface of the same. A locking mechanism (24) is configured to engage with the single recess (22) to prevent movement of the guide piece (10) in the longitudinal direction after insertion of the guide piece (10) into the guide claw.

Abstract: A face conveyor includes a continuous conveyor formed by a conveyor chain with entrainment plates that are connected to chain links and which, when conveying, circulates in an outward run and a return run, each of which are guided in trough portions by trough elements, which are arranged in a row. Guides provided on each trough element include a first guide on a working face side and a second guide at a spacing from a goaf side. The first guide on the working face side is secured on the trough element between the outward run and the return run. The outward run and the return run extend in a laterally offset manner with respect to each other, and the trough portion guiding the entrainment plates in the outward run is open on the working face side.

Abstract: A chain wheel for driving or diverting a conveyor of an apron conveyor including transport plates is disclosed. The transport plates may be releasably connectable via a chain connecting parts to the conveyor chain. The chain wheel may have a chain wheel body including a lateral face. The chain wheel may also have teeth arranged peripherally offset over the lateral face. In addition, the chain wheel may have bearing faces. The bearing faces may be arranged peripherally offset over the lateral face between two adjacently situated teeth. The bearing faces may also be configured to support the chain connecting parts.

Abstract: A method and a longwall face extraction installation have a device for locating persons and/or mobile machines in mine caverns using RFID technology. Base stations are arranged in a distributed manner along the mine cavern to be monitored and have a transmitter and a receiver. At least one RFID transponder is associated with the person or machine to be located, which has stored identification data, can be activated using the base station and can be read in a contactless manner using the base station. In order to provide a method for locating persons and a longwall face extraction installation, in particular for coal mining, which make it possible to effectively use RFID technology, the transmitters of adjacently positioned base stations along a region of the mine cavern to be monitored successively emit their transmission wave in order to activate an RFID transponder.

Abstract: An extraction machine for an extraction installation is disclosed. The extraction installation may have a chain having a first chain strand section with a first end and a second chain strand section with a second end. The first and second chain ends may be connectable to the extraction machine for moving the extraction machine. The extraction machine may have a first chain mount configured to be connected to the first chain strand section. The extraction machine may also have a second chain mount configured to be connected to the second chain strand section. In addition, the extraction machine may have a first pre-tensioning device for building up a pre-tensioning force acting on the first chain mount such that a pulling force acts on the first chain strand section in the direction of the second chain mount.

Abstract: A replaceable guide piece (10) for an extraction or coal plough (100) is provided. The replaceable guide piece (10) includes a generally U-shaped guide piece body (12) configured to be inserted into a guide claw (14) of the plough (100). A single recess (22) is formed in a central portion of a guide piece body (12) to extend at an angle (?) from an upper side of guide piece body (12) to a side surface of the same. A locking mechanism (24) is configured to engage with the single recess (22) to prevent movement of the guide piece (10) in the longitudinal direction after insertion of the guide piece (10) into the guide claw.

Abstract: The invention relates to a multipart chain fixing device for securing at least one conveyor chain on a trough element of especially an underground scraper chain conveyor. The fixing device comprises a bridge part (60), which has a bridge bar (62) that at least partially overlaps the conveyor chain in a positive-locking manner and ends in two lateral side end portions (61). It also comprises two side parts (70), which are fastenable to the trough element pan and to which the side end portions 61 are releasably securable by positive-locking means. For providing a chain fixing device, inclusive of the associated trough element and the individual components, which offer increased safety in underground usage, combined with simple assembly, the side parts (70) are releasably fastenable in a positive-locking manner in cavities in the conveyor floor of the trough element.

Abstract: A shield canopy for a shield-type support for underground mining having a canopy plate and a supporting structure being welded on below the canopy plate and having a plurality of longitudinal spars which extend from a rear canopy region up to a front canopy region. At least two of the longitudinal spars having section struts which are provided with a top section flange and a web running perpendicularly to the top section flange, and the canopy plate and the section struts are angled upwards in the front canopy region.