Abstract: A cutter bit assembly comprises a holder and a cutter bit. The holder is formed with a pocket into which the cutter bit can be inserted. The cutter bit is retained within the pocket by means of an arcuate wedge inserted into a tapered gap formed between respective curved support faces formed on the cutter bit and the holder.

Abstract: In a tunnel driving apparatus, and particularly such apparatus where a work face is supported by fluid, a cutting appliance is employed which is composed of a swinging arm carrying a cutter head. The arm can range over the face to detach material therefrom with the cutter head. Means for driving the cutter head is accommodated entirely within the arm itself and a conduit or the like extends through the arm and serves optionally to remove debris by suction or to convey pressure fluid to the face to assist the cutter head.

Abstract: A mine roof support unit has a roof shield for supporting the roof of a mine working, and a goaf shield for screening off the goaf space of the working. The mine roof support unit is provided with dust suppression means constituted by a flat-section spray nozzle arranged along the front edge of the roof shield, or along the top edge of the goaf shield. The spray nozzle is directed upwardly away from the roof support unit and towards the goaf space.

Abstract: A hydraulic ram for use as an advance ram in mining operations has a plurality of permanent magnets embedded in its piston rod. At least one sensor is associated with a guide bush fixed to the piston rod end of the cylinder of the ram. The or each sensor is accommodated within a respective pocket formed in the guide bush. The pocket(s) can be closed off by a detachable closure member.

Abstract: A plough for winning material (such as coal) from a face has a plough body which supports a carrier for roof-level cutters. Means are provided for adjusting the vertical position of the carrier with respect to the plough body. The adjustment means comprises a worm mounted on the plough body, and a toothed rack associated with the carrier. The worm meshes with the toothed rack. The worm is driven through a reduction gear which is located on the goaf side of the carrier.

Abstract: A hydraulic coupling device is connected to a multi-line hose comprising a plurality of hydraulic lines housed within a flexible sheath. The coupling device comprises a cylindrical nut, a plurality of plug pins housed within the nut, and means for holding the plug pins within the nut. The plug pins are each connectible to a respective line of the hose. The holding means comprises a holding disc, a retaining disc, and a sleeve. The sleeve is connected to the sheath of the multi-line hose. Each of the plug pins is provided with a pair of longitudinally-spaced collars which define therebetween a peripheral groove. The retaining disc is provided with a respective aperture for each of the plug pins. Each of the apertures has a diameter which is slightly greater than the diameter of one of the collars of the associated plug pin. The holding disc is provided with a plurality of radial slots. The peripheral groove of each plug pin engages within a respective radial slot of the holding disc.

Abstract: A compact hydraulic control device for use with mining apparatus is composed of a housing block containing tappet-operated valves. A multi-part cam shaft serves selectively to operate the valves by displacing the tappets by manual control effected by external levers. To automatically restore the cam shaft back into a neutral position as a "dead-man's handle" restoring system use is made of a pair of piston and cylinder assemblies mounted as detachable cartridges in parallel locations within bores in the housing block and having push rods which act on a cam of the cam shaft under the action of hydraulic or pneumatic pressure medium.

Abstract: A connecting device usable with hydraulic or pneumatic multi-line hoses in mineral mining has a block containing bores interconnecting bore-outlets formed on end faces of the lock extending perpendicularly to one another. The bore outlets are disposed on common pitch circles on the end faces at equal spacings. Detachable fittings mate with the end faces. One of these fittings holds plug-pins in identical sockets formed by the bore-outlets. The other of the fittings is coupled with a multi-line hose with similar plug-pins which locate in sockets formed by the fitting in correspondence with the associated bore outlets. Provision is made for one of the plug-pins of each group to serve as alignment means for the other components and the plug-pin of the one fitting and corresponding socket of the other fitting can be re-orientated around the pitch circles of the end faces at will.

Abstract: A mine roof support has a main roof-engaging structure 2 carried by hydraulic props 6 in known manner and an auxiliary roof-engaging structure at the front end of the main roof engaging structure. The auxiliary roof-engaging structure can be swung up and down and is itself of multi-part construction with one component 7 directly linked to the main structure and another selectively extendible forward component 8 mounted to the one component. One hydraulic piston and cylinder unit 9 is provided for swinging the auxiliary structure and for setting the structure against the roof and another such unit 10 is provided for selectively extending and retracting the forward component thereof. A hydraulic control arrangement 16-18 associated with the units ensures that when the forward component is being advanced the roof setting pressure acting on the auxiliary structure is automatically reduced.

Abstract: A hydraulic connecting device is disclosed, the device being for interconnecting a multi-line hose and a coupling device. The hose has a plurality of flexible hydraulic conduits bunched together within a protective sheath. The coupling device has a plurality of plug pins held within a casing by a retaining disc. The casing is attached to the protective sheath by the connecting device. The connecting device is constituted by a clamping sleeve, which is connected to the protective sheath, and a connecting sleeve, which is connected to the casing. The two sleeves are telescoped together at end portions thereof and are joined together by means of a rotary connection which resists tensile forces. The rotary connection is constituted by a releasable securing element.

Abstract: A mobile mine roof support assembly has three mine roof support units coupled together by a common transverse beam. Roller devices are mounted beneath the floor sills of the support units. The roller devices are spring biased away from their floor sills so that they can lift the floor sills away from the floor of a working when the assembly is to be moved. At least one roller device of each support unit is a steerable roller device so that the assembly can be steered round bends. Each steerable roller device is pivotally mounted on its floor sill about a vertical axis, and is provided with an associated steering device. The steerable roller devices are preferably coupled together by means of a common steering device.

Abstract: A telescopic prop for use in mine workings extends and retracts over three stages. The prop has an outer main base member 1 with respective first, second and third concentric inner members 2, 3, 4 disposed one within another. The first inner member has a piston 6 in which is arranged a non-return valve 23 which normally shuts off communication between a working chamber 20 associated with the first and base members and the working chambers 22, 27, 29 pertaining to the other members. A plunger 24 is provided to open the non-return valve when the first inner member is nearly fully retracted inside the base member so that after retraction of this stage the other stages can be retracted. The second or intermediate member also employs a piston 9 which is connected via a rod 13 with an auxiliary piston 15 disposed in a working chamber associated with the uppermost third member.

Abstract: A mine roof support has a goaf shield with a lemniscate guide system linking the shield to floor-engaging skids. A walking-mechanism is disposed in a channel between the floor skids. In order to prevent rubble or goaf material from penetrating into the channel the guides of the lemniscate system have connections which are spaced one above the other and to which one or several screen plates can be removably and replaceably attached with the aid of push-in locking-bars. The screen plates also advantageously serve to keep the floor skids apart by a minimum distance to prevent jamming of the walking mechanism.

Abstract: Apparatus for cleaning bar-mounted remnants of carbon blocks includes a machining station defining a working position. A breaking device is provided for loosening incrustations adhering to the remnants at the working position. The individual remnants are moved into the working position by a lifting table. The breaking device is constituted by two blades which are displaceable transversely of the direction of movement of the lifting table. An overhead conveyor is provided for moving the remnants into the machining station.

Abstract: A rack assembly for a mine winning machine drive arrangement is described. The rack assembly is associated with a longwall conveyor along which a mine winning machine is movable by the drive arrangement. The rack assembly is constituted by a plurality of rack sections and a plurality of support members for connecting the rack sections to the longwall conveyor. Each of the rack sections has a respective downwardly-extending coupling pin at each end thereof, each of the coupling pins extending through an elongate slot in a respective support member with a predetermined amount of play. Each of the coupling pins is provided with a retaining member for preventing that coupling pin from moving out of the associated slot. The rack assembly is such that the rack sections of each adjacent pair of rack sections are relatively pivotable in vertical and horizontal directions, and are relatively movable to a predetermined extent in the longitudinal direction of the rack assembly.

Abstract: A guide assembly for a curved section of a scraper-chain conveyor comprises a housing and two pulley wheels which are rotatably mounted within the housing. The pulley wheels constitute means for guiding the scrapers of a scraper assembly around the curved section. Each of the pulley wheels has an inner wheel part and a two-part scraper-engaging rim detachably connected to its inner wheel part.

Abstract: Apparatus for controlling the position of a mineral mining machine, such as a plough, guided for movement along a guide comprises inclined piston and cylinder units connected via ball-and-socket joints between connectors at the ends of elongate beams guided on roof supports and brackets on a conveyor forming or supporting the guide. The cylinder of each unit has a ball at its upper end received in a socket on one of the brackets. This upper ball has a stepped profile with a shoulder and an end region of different radii of curvature.The piston and interior of the cylinder are also stepped with innermost regions of reduced diameter. These measures reduce the overall length of the unit.

Abstract: A mineral winning machine in the form of a coal plough has adjustable floor cutters. To set the floor cutters at different heights use is made of arcuate levers as carriers for the floor cutters which are slidably guided as known per se. Eccentric stop members engage on the upper ends of the levers and are rotatable to bring different faces into engagement with the levers. Locking means holds each stop member in its rotational setting and the locking means can be released for re-setting by axial displacement of the stop member against a spring force.

Abstract: A scraper-chain conveyor has a scraper-chain assembly composed of a pair of outboard chains with scapers therebetween. The assembly passes along upper and lower runs and the lower run is enclosed. Each scraper has an upstanding front face and a lower foot face perpendicular thereto. The foot face slides along a floor of the conveyor and a scraping edge between the front and lower faces transfers material in the upper run. To prevent fine material building up in the lower run, the scraper has a further scraping edge formed between the front face and an upper face generally parallel to the lower face. This further scraping edge slides along the base of the lower run.

Abstract: A sprocket wheel has a plurality of equi-spaced circumferential teeth, and a plurality of pockets positioned between the teeth. A central circumferential groove in the sprocket wheel divides each of the teeth into two parts. Each of the pockets is shaped to engage with a link of a drive chain, each of the pockets being formed partially by flanks provided on each of the two parts of each of the pair of adjacent teeth defining that pocket. The flanks constitute chain link bearing faces, and each of the flanks has at least three separate bearing surfaces.