Abstract: A wear pad for a longwall mining shield base lift. The wear pad includes at least one spanner hole for rotating the wear pad with a lever, at least one threaded retaining hole, and a retaining bolt threaded through the retaining hole until it contacts a cylinder rod to which the wear pad is to be attached.

Abstract: A machine operating at an underground mine site is provided. The machine includes an engine, a frame, and a vision assembly. The vision assembly is configured to generate a vision feed of a portion of a roof of the mine site. The roof of the mine site has a plurality of bolts arranged in a predefined pattern. The vision assembly is configured to capture at least a portion of the predefined pattern of bolts based on a field of view of the vision assembly. A controller is communicably coupled to the vision assembly. The controller is configured to receive the vision feed of the portion of the roof of the mine site. The controller is configured to compare the vision feed with the predefined pattern of bolts. The controller is configured to determine a current position of the machine at the mine site based on the comparison.

Abstract: Methods and equipment have been developed that combine the use of continuous miners, flexible conveyor trains, and longwall mining techniques to provide flexible and efficient removal of resources from subterranean formations. Some mining operations use a powered roof support comprising: a canopy configured to directly contacts a roof of a mine; a base configured to rest on a floor of the mine, the base comprising a spill plate and a push cylinder with a maximum stroke greater than 11 feet; and a pair of hydraulic legs attaching the canopy to the base.

Abstract: A lift cylinder arrangement is disclosed for a hydraulic support frame for underground mining. The support frame has a lift cylinder for lifting the base shoes during advancing, which is supported on the one hand on a return rod and on the other hand, in a pivoting manner, with an end supporting head to a drawbar connected to the base shoes. In order to allow a simple, rapid and reliable connection between the supporting head and the drawbar, the supporting head is connected to the drawbar by a plug-type locking system comprising two plug-type locking elements, which include first locking notches on the drawbar, and arranged complementarily thereto second locking notches on the supporting head, whereby the plug-type locking elements engage in at least one of the locking notches with clearance.

Abstract: A grid layout system including a grid dispenser mounted on a boom of a continuous miner for movement with a cutting drum to cut a passageway in a rock face. A roll of grid material, such as integral biaxially oriented geogrid, is fed from the dispenser and maintained under tension as it is positioned against the ceiling of the passageway to be secured thereto as a supplemental support. The tensioning device takes up any slack in the grid material during the cutting operation to preclude engagement of the grid material with the cutting drum. The edges of the grid material are longitudinally folded over the middle section and temporarily held in this manner to provide the roll of the grid material within the dispenser with a width less than the cutting drum. A spreader bar opens the grid material to its full width as it is dispensed.

Abstract: A sliding stabilizer is a machine for supporting the roof in the working zone of a mine. A sliding stabilizer operates in tandem with a mining roof support machine. A sliding stabilizer is capable of supporting the mine roof independently of the roof support machine. A sliding stabilizer has a peak roof covering, a flexible sheet that extends toward the roof covering of a support machine, and a rotating retractable leg. The retractable leg rotates from the mineral seam to inside the roof covering of a support machine. The retractable leg propels the peak into the working zone of the shearer. A sliding stabilizer supports a previously insupportable roof.

Abstract: The present invention is directed to a movable load support used for supporting the roof in underground excavations. The load support includes a primary roof support carried on a base frame and an auxiliary roof support also carried on said base frame but laterally disposed from the primary roof support. The auxiliary roof support is longitudinally and laterally moveable with respect to the primary roof support to successively provide roof support to adjacent areas of the roof.

Abstract: A continuous mining linear advance system comprises a dual action drum cutter for removing coal from a face of the entry. The dual action drum cutter removes the coal from the face by shearing across the face in a direction transverse to the direction of advance and by cutting directly into the face in the direction of the advance. A conveyor system operatively associated with the dual action drum cutter carries away coal removed from the face of the entry in a continuous, non-interrupted manner. A number of self advancing roof supports positioned adjacent the dual action drum cutter support the roof in the immediate vicinity of the face. Roof bolting devices positioned behind the self advancing roof supports install roof bolts, and a pillar casting system positioned behind the roof bolting devices constructs a series of pillars which provide long term roof support.

Abstract: A mine tunnel support system of the type comprising spaced interconnected support sections is described. The support system is advanced along the tunnel in the forward direction in which mining is proceeding. Bolting machines may be carried on the support sections. A drill may be provided on one section and a bolt inserter provided on a section rearwardly thereof. As the system is advanced, the bolt inserter can insert a bolt into a hole previously formed by the drill. The operation of providing roof bolts is therefore split into a number of stages. A mechanism for erecting and/or pre-stressing permanent arch supports may be provided at the rear of the sections.

Abstract: A mine roof support employs a pair of floor skids carrying hydraulic props on which a roof-engaging structure is mounted. A goaf-shield is pivotably mounted to the roof-engaging structure and is connected with a lever system to the floor skids. A shifting and guide mechanism is disposed between the floor skids and takes the form of an hydraulic ram connected at the rear to a floor rail disposed beneath the ram. The ram is supported at the front end by a bridge member connecting the front ends of the skids together. An hydraulic lifting unit is mounted on the bridge member and when extended the unit bears on the floor rail to partially lift the skids as the shifting ram is operated. The lifting unit can be mounted to the bridge member in one of several alternative height positions.

Abstract: A mine roof support frame has a pair of spaced-apart floor skids on which hydraulic props support a roof engaging structure. A shifting mechanism with a ram in a trough-like housing and a guide beam is positioned between the skids and serves to displace the frame relative to a scraper-chain conveyor and vice versa. The guide beam is a flat plate with a width more or less the same as the space between the skids and rests directly on the floor. The piston rod of the ram is coupled to the guide beam near the conveyor, the ram cylinder is coupled to the housing and the housing is coupled to the skids at the stowage end. The ram housing has a guide rail on the underside which mates with a guide element on the top of the guide beam. Levers pivotably coupled to the floor sills in front of the ram housing are operated by piston and cylinder units to engage on the guide beam to lift the floor skids partially during advancement of the frame.

Abstract: A walking mining prop has a skid-lifting assembly in the region of the ram which braces the roof cap with respect to the skid formed by a bridge from which lifting cylinders are articulated and suspended. The pistons of these lifting cylinders are articulated to a pressure plate which at least partly surrounds the guide rods of a guide-rod assembly on which the skid is guided, a mechanism being provided to advance the skid relative to the guide-rod assembly.

Abstract: A roof support for the ceilings of excavated spaces underground and particularly for supporting caving edges for pillar recovery in coal mines is described. The roof support has a roof bar connected to a base frame by hydraulically extendable props and by a lemniscate mechanism. The props are articulated to the base frame and to the roof bar. A link of the lemniscate mechanism has a predetermined bending point. Since this link fails when overloaded before the remainder of the apparatus, it is the only element that need be replaced when the apparatus is overloaded. Thus, the device may be economically repaired.

Abstract: A mine tunnel support system of the type comprising spaced interconnected support sections is described. Each section includes at least one bearing member which, when the section is in the first, loaded state, bears against the roof of the tunnel. Drive means are provided for changing the location of each support section when in the non-loaded state. The support system is advanced along the tunnel in the forward direction in which mining is proceeding by bringing each section sequentially into the non-loaded state, commencing with that at the rear, moving the section with the drive means into proximity with the next forward section, and thereafter returning the section to the loaded state. Bolting machines may be carried on the support sections. A drill may be provided on one section and a bolt inserter provided on a section rearwardly thereof. As the system is advanced, the bolt inserter can insert a bolt into a hole previously formed by the drill.

Abstract: The mobile stope support apparatus comprises a number of individual units (10) which are interconnected by hydraulic cylinders (12). Each of the units (10) has a series of upright, double-acting legs (20). The legs (20) have independent bases of rounded shape and they are pivoted to an overhead canopy (22) which can be raised and lowered by appropriate actuation of the legs. Each unit also has a fore-and-aft hydraulic cylinder (34) which is connected to a common rail (37), the cylinder (34) being pivotable, by the action of a cylinder (36) in an upright plane to raise and lower the rail. By appropriate sequential operation of the various cylinders, the units can be advanced in turn to advance the whole apparatus. In addition, by appropriate operation of the cylinder (36), the front legs (20) can be lifted off the footwall to facilitate movement of the unit over a rough or uneven footwall.

Abstract: A mine roof support includes a ground engaging base section, a roof engageable canopy, and hydraulic props for raising and lowering the canopy relative to the base section. An advancing mechanism is provided for advancing the roof support towards the mine face, and a base lifting mechanism is provided for raising one end of the roof support prior to advancing the support towards the mine face. The base lifting mechanism includes a lifting ram mounted with respect to the base section for slidable movement between an upper operative position in which the ram can be extended to lift the one end of the roof support clear of the ground and a lower position in which the canopy can assume a position relative to the base section lower than would be possible with the lifting ram in its upper operative position.

Abstract: Mine roof support comprising a base including a pair of skids, a roof engaging canopy, jacks acting between the base and the canopy, an auxiliary jack connected to the base for lifting or lowering at least part of the base when the support advances and a lost motion arrangement connected between the base and the auxiliary jack for aiding movement of the base and the roof engaging canopy toward each other. The lost motion arrangement is connected to each of the skids by a pivotal connection which permits the front end of one skid to move vertically to a limited extent with respect to the front end of the adjacent skid.

Abstract: An electro-hydraulic control system has a valve unit allocated to a roof support (support shield, support trestle or the like) and equipped with electromagnetic valves. The unit is controlled by a control unit via a cable which includes two current supply leads serving as a common current supply for all the electromagnetic valves and at least one data bus through which an actuator connected with the valve unit is actuated from a microprocessor of the control unit. The actuator itself consists preferably of a shift register through which all the electromagnetic valves can be actuated.

Abstract: A flooring system as disclosed which includes a substructure placed on an earth surface, which supports a floor structure. The substructure is composed of a plurality of longitudinally-extending I-beams interconnected by longitudinally-extending styrofoam blocks. A floor structure is connected to the substructure, the floor structure including flooring pieces having a long side and a short side. The flooring pieces are connected to the substructure so that the long sides extend transversely to the length of the I-beams. In an alternative embodiment, the I-beams include a support and location leg for connecting the styrofoam blocks. According to a method of the invention, the substructure and floor structure are interlocked by the criss-cross pattern described.

Abstract: A method and apparatus for mechanized, stress control mining includes the process of continuously cutting and advancing a broad mine face to form a mine opening having a low aspect ratio and an envelope of ambient stresses in the earthen media that protects the roof and floor from failure. At the advancing face the roof is supported by the apparatus of the invention, a superlifting stress control machine. The stress control machine comprises a plurality of support column assemblies, each capable of lifting up to 10,000 tons. The support column assemblies are arrayed at the mine face, and are interconnected by telescoping hydraulic arms so that individual support columns may be unloaded and translated with respect to the operating, anchored support columns. Alternatively, the column assemblies may be mounted in groups on tracked vehicles for high mobility.

Abstract: A mine roof support has a roof engaging canopy 23, a floor engaging base 12, and a hydraulic jack 24 acting between the canopy and the base for urging the canopy and the base apart. The hydraulic jack 24 is provided with at least two different locations, movement of the jack means 24 from one location to another location bringing about an alteration in the distance between the canopy and the base. The invention makes it possible to provide a hydraulic jack having a first working position in which the hydraulic jack is arranged in the optimum position to support a mine roof, and a second stowing position for transportation purposes.

Abstract: The invention refers to a trestle (1) being displaceable on caterpillars (2) and having an approximately rectangular cross section and serving the purpose of supporting the roof in underground cavities, in particular serving the purpose of securing the excavating edge when recovering pillars (19) in coal mining, the trestle comprising a cap (4) being supported against a base frame (3) by hydraulically expandable props (5) extending approximately vertically relative to stratification. The trestle (1) has, related to the travelling direction of its floor chassis (2), at its both sides supporting plates being adjustable in outward direction and/or horizontal driveable caterpillar chassis being adjustable in outward direction. The supporting plates (22, 23) and/or the lateral caterpillar chassis (20, 21) are adjusted against the frame of the trestle by means of hydraulic or pneumatic pistons and cylinders and are adjustable in outward direction.

Abstract: The invention refers to a movable trestle of approximately rectangular horizontal projection and serving the purpose of supporting the roof in underground cavities in particular serving the purpose of securing the excavation edge when recovering pillars in coal mining, comprising a cap (2) supported against a base frame (1) by hydraulically extensible props extending approximately in vertical direction to stratification. The lower portion of the trestle is, preferably at all sides, covered by a stationary shielding means against the ingress of rubble into its interior and horizontal protective plates (3) overlapping one another in a scale-like manner and being guided on sliding plates (8) for relative shifting movement in height direction are provided within the area of the expandable portion of the trestle. The protective plates (3) are arranged on the rear side (12) of the trestle and on the both sides (10, 11) adjoining the rear side of the trestle.

Abstract: A mineral mining installation comprises a roof support unit and an advance mechanism. The roof support unit has a floor sill constituted by two floor girders. The advance mechanism comprises a hydraulic advance ram, the advance ram having a relatively-displaceable cylinder and a piston rod, and a device for selectively limiting the working stroke of the ram. The stroke-limiting device comprises a stop fixed to the cylinder of the advance ram, and an adjustable stop member which is mounted on the side wall of one of the floor girders.

Abstract: The invention refers to a movable supporting frame for supporting the roof in underground cavities, in particular for securing the excavating edge when recovering the pillars in coal mining, comprising a cap (5) supported against a base frame (1) by means of hydraulically extendable props (3) and a lemniscate drive means (4), the props (3) being pivotally connected with the base frame (1) and with the cap (5). The props (3) are essentially perpendicularly oriented relative to stratification and are linked to the base frame (1) and to the cap (5) in a universally pivotably manner, noting that preferably four props are arranged at the corners of a rectangle as seen in a plan view. The lemniscate drive means (4) is connected with the base frame (1) for swivelling movement in transverse direction relative to the plane defined by the lemniscate guides (8, 9) and is adjustably supported against any swivelling movement and is connected with the cap (5) for universal swivelling movement.

Abstract: A hydraulic control arrangement comprises a first hydraulic ram, a second hydraulic ram, and a hydraulic control circuit associated with the first and second hydraulic rams. Each of the hydraulic rams has a cylinder, a piston reciprocable within the cylinder, and a piston rod fixed to the piston. Each of the hydraulic rams has a cylindrical working chamber and an annular working chamber positioned on opposite sides of its piston. The piston rod of each hydraulic ram constitutes the cylinder of a respective metering ram, a respective metering piston being reciprocable within the cylinder of each metering ram to define a metering chamber therewithin. The hydraulic control circuit includes a line, which interconnects the two metering chambers, and a hydraulic valve positioned in a hydraulic fluid supply line leading to the cylindrical working chamber of the second hydraulic ram.

Abstract: Attachment means are provided for attaching a mine roof support to an abutment, (e.g. a flexible conveyor) the attachment means comprising a ram arrangement in the form of at least two rams 25, 26 operable to effect relative movement between the mine roof support and the abutment. The provision of two or more rams instead of the conventional single ram means that smaller bore rams may be used, for example a 60 mm bore as opposed to 41/4 inch bore and this makes it possible to cover or encase the rams in a protective shield without reducing the vertical space available to a miner underneath the mine roof support.

Abstract: A mine roof support unit includes a pair of generally parallel floor girders, and an advance mechanism positioned between the floor girders. The advance mechanism comprises a hydraulic advance ram and a guide rod system. The advance ram is pivotally connected between the guide rod system and a cross member which interconnects the floor girders. The guide rod system is attachable to a longwall conveyor positioned adjacent to a work face. The cross member is engageable with the floor girders in such a manner that the floor girders are relatively displaceable in a vertical direction. Each of the floor girders is provided with a respective hydraulic lifting ram, the arrangement being such that the lifting rams can be operated to lift one of the floor girders relative to the other floor girder.

Abstract: A so-called externally-situated advance mechanism is arranged between the floor sills of adjacent mine roof support units. The advance mechanism includes two laterally-spaced guide rods, and two advance rams positioned above the guide rods. The front ends of the guide rods are connected to a head-piece. A bridge is connected to the two guide rods at a distance behind this head-piece. The piston rods of the two advance rams act on this bridge. The cylinders of the rams are connected, at a distance therebehind, to brackets fixed to the floor sills. Said brackets form guides for the guide rods.

Abstract: A mine-roof support has a floor beam, an advancing ram and a relay bar. A bell-crank lever is pivotally-connected to the floor beam and the advancing ram is pivotally-connected to the bell-crank lever. One arm of the bell-crank lever has a member which may be in the form of a ball. The pivotal connections are such that, on extension of the ram, when the relay bar is connected to part of a conveyor, the bell-crank lever is initially urged downwardly from an inoperative position away from contact with the relay bar, into an operative position in contact with the relay bar, thereby to apply an upward thrust to the front end of the support and to maintain an upward thrust during further extension of the ram and consequential advancing movement of the mine-roof support towards the conveyor.

Abstract: A mine roof support system including a relief valve communicable with the props of each roof support through respective control valve means, and a main return pipe for receiving liquid discharged, by way of the relief valve, from the props when liquid at high pressure is no longer supplied thereto and the roof support is being advanced. A movable element of the relief valve comprises at least two relatively-movable and connected parts and is so co-operable with its seating as to ensure that when the support is so advancing a substantially constant predetermined back-pressure is maintained in the props sufficient to maintain the support in contact with the mine roof. If the pressure in the main return pipe exceeds the pressure then subsisting in the control valve means, one of the parts of said element is caused automatically to close onto the seating.

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 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: A fixing bridge for attachment to the goaf side of a channel section on a scraper-chain conveyor, is provided with connectors for the attachment of anchoring devices. A first connector is provided adjacent to one end of the fixing bridge, and a second connector is provided adjacent to the other end of the fixing bridge. The second connector is vertically off-set with respect to the first connector.

Abstract: A mine roof support unit has a roof bar supported on a floor sill by hydraulic props. The floor sill is constituted by a face-side floor sill part and a goaf-side floor sill part. The two floor sill parts are telescopically interconnected. Each of the floor sill parts supports a pair of hydraulic props. Hydraulic rams are provided for moving each of floor sill parts relative to the other floor sill part in the direction of roof support unit advance.

Abstract: This invention provides mine equipment for sensing the advance of mobile equipment, particularly on longwall face conveyors the equipment comprises two mine roof supports provided with sensor means for sensing relative movement between the associated roof supports and an elongate bar component secured to the conveyor and extending between the two supports in a direction rearwardly of the conveyor. The elongate component is magnetized so that a magnetic field is induced adjacent thereto, the induced magnetic field intensity varying longitudinally of the elongate component.

Abstract: A roof support unit for a longwall mineral mining installation has a roof shield supported above a floor sill. A first hydraulic ram is provided for advancing the roof support unit. The roof shield is provided with a forward extension which is advanceable by means of a second hydraulic advance ram. A hydraulic control arrangement, which includes the two hydraulic advance rams is provided for controlling the advance of the roof shield extension in dependence upon the working stroke of the first hydraulic advance ram. The control arrangement is such that the amount of hydraulic fluid supplied to one of the pressure chambers of the second hydraulic advance ram is dependent upon the amount of hydraulic fluid expelled from one of the pressure chambers of the first hydraulic advance ram during the working stroke of the first hydraulic advance ram.

Abstract: A longwall mineral mining installation has a conveyor and a plurality of roof support units positioned side-by-side on the goaf side of the conveyor. Each roof support unit has a roof shield having an advanceable shield extension. Each unit has a first hydraulic ram for extending its shield extension, and a second hydraulic ram for advancing the conveyor. The extension of each first ram is controlled in dependence upon the retraction of one of the second rams (either the second ram of the same unit or that of an adjacent unit). This control is effected by controlling the supply of pressurized hydraulic fluid to the first rams. In one embodiment this is carried out by a control valve which has a spring-loaded plunger which engages with a series of equispaced cams on the movable cylinder of the associated second ram. In another embodiment, the piston rods of the rams are provided with series of equispaced magnets.

Abstract: Coal in the roof of a seam being mined by the long wall method is recovered by supporting an elongated area of the seam roof using a plurality of cradle supports, the front cradles being moved forward stepwise parallel to the long wall to form a passage with cantilevered roof supporting arms of the rear cradles. When the rear cradle at one end of the passage is moved forward into engagement with the front cradles, the coal in the roof is left unsupported, is collapsed, and is removed via a conveyor and a loader in the passage.

Abstract: A mineral mining installation comprises a longwall conveyor, and a plurality of roof support units positioned side-by-side along the goaf side of the conveyor. The roof support units are positioned to define an access area between the conveyor and the roof support units. A plurality of hydraulic bracing rams act on the conveyor to brace the conveyor longitudinally. Each of the bracing rams is pivotally attached to a floor sill of a respective roof support unit. The hydraulic bracing rams are positioned at the goaf-side edge portion of the access area. The bracing forces are transmitted from the bracing rams to the conveyor via respective transverse arms attached to the bracing rams and to the conveyor.

Abstract: A mine roof support unit is constituted by two detachably connected parts. Each of the parts has a floor girder which supports a roof bar by means of a hydraulic prop. The roof support unit is intended for use at the lower end of an inclined longwall working which meets its access gallery at an angle other than 90.degree.. The detachability of the two parts enables one of these parts to be removed from the working as its face is advanced. The removed part can then be transported to the other end of the working. Each of the parts is provided with means for detachably connecting an advance mechanism.

Abstract: A roof support assembly is constituted by a plurality of roof support units and a plurality of advance mechanisms. The units are positioned side-by-side along a longwall face of a mineral mining working. Each advance mechanism comprises a pair of generally parallel hydraulic advance rams and a guide rod system constituted by a pair of resilient generally parallel guide rods. Each guide rod system is attached, at one end, to a conveyor extending along the longwall face. The other end of each guide rod of each advance mechanism is attached to a respective slide piece which is slidably guided on a respective guide rail which is attached to a respective floor girder of a roof support unit. The slide pieces are attached to the piston rods of the hydraulic advance rams. The cylinders of the hydraulic advance rams are attached to one of the adjacent floor girders, and the slide piece attached to the piston rod of hydraulic advance ram is attached to the guide rod system.

Abstract: A self-advancing mine roof support has a beam-like abutment adapted to be disposed generally adjacent and parallel to a work face. Three roof support elements are spaced apart along the abutment and are pivoted to the abutment. The abutment may be angled relative to the direction of advance by arranging the three support elements in staggered formation. A beam of the central support element is pivoted to the abutment. The two outer roof support elements are connected to the abutment by a linkage, e.g., guide arms, which allows the abutment to pivot about the beam of the central element without changing the distance between the three elements as measured at right angles to the direction of advance.

Abstract: A roof support unit has a pair of spaced floor girders and an advance mechanism comprising a hydraulic advance ram and a pair of relay rods connected, at one end, to a head-piece which is attached to a longwall conveyor. The other ends of the relay rods are attached to a guide element which is slidably guided by a pair of guide rails attached to the mutually-facing sides of the floor girders. The hydraulic advance ram is pivotally attached to the guide element and to the floor girders. Means are provided for aligning the ends of the floor girders remote from the head-piece when the hydraulic advance ram is pressurized.

Abstract: A longwall mineral mining installation has a longwall conveyor and a plurality of roof support units positioned side-by-side at the goaf side of the conveyor. The hydraulic appliances of the roof support units, such as their hydraulic props, hydraulic advance rams and hydraulic control valves, are supplied with pressurized hydraulic fluid from hydraulic supply lines which run along the goaf side of the conveyor. A plurality of flat, plate-like intermediate members are provided at the goaf side of the conveyor. These intermediate members are formed with internal ducts for feeding the hydraulic fluid from the supply lines to the hydraulic appliances of the roof support units.

Abstract: A mechanized longwall system for mines is provided which includes face roof supporting units disposed along the longwall and connected to a face support track by hydraulic advancing cylinders, each unit including a floor and roof element, a drift transport track mounted perpendicularly to one end of the face transport track, including two drift supporting units coupled with hydraulic linkages to the face supporting units, a guide system arranged on one of the floor elements of the drift supporting units and guiding a transfer unit in the longitudinal direction of the drift transport track, the arrangement being such that shifting of a drift supporting unit is accompanied by a simultaneous shifting of the face conveyor apparatus.

Abstract: The invention is concerned with a hydraulic shield-type support for supporting roofs in mines comprising a pair of base slides between which is located a channel-section guide beam supporting an hydraulic ram. At the rear end of the hydraulic ram a yoke is pivotally connected at a central part thereof to the rear end of the guide beam, the two outer portions of the yoke being pivotally connected to the rear end portions of the base slides. The front extendable end of the ram is connected to an elongate flat tongue which is longitudinally slidable in the guide beam underneath the hydraulic ram.

Abstract: A mobile self-propelled mine roof support system employing pairs of individually self-propelled roof support units movable along opposite ribs of a mine room to follow an advancing mine face. Each support unit comprises an elongated, wheel-mounted frame positioned along the adjacent rib. Pairs of vertical jacks are connected to opposite sides of the frame, being positioned loosely, and vertically movable, within oversize openings in brackets attached to the frame. A foot plate is universally pivotally attached to the lower ends of each pair of jacks and extends across the underside of the frame. A top-supporting canopy is universally pivotally attached across the upper ends of each pair of jacks and has an overhanging portion extending cantileverly into the room toward the opposite support unit. The jacks have external flanges engagable with the brackets.

Abstract: An improved advancing mechanism for a dual auger continuous miner of the type adapted to be advanced by a pair of anchoring jack assemblies, a pair of cables extending from the anchoring jack assemblies to a pair of winch mechanisms on the sides of the frame. The mechanism includes a mounting arm mounted on each side of the frame for movement about a vertical axis, a telescoping structure extending longitudinally between each mounting arm and the associated anchoring jack assembly and hydraulic piston and cylinder units for effecting the pivotal movement of each arm and the telescoping movement of each telescoping structure.

Abstract: A roof support unit for use in a mineral mining working has a roof shield supported on a floor sill by means of at least two hydraulic props. A goaf shield is pivotally linked to both the roof shield and the floor sill. At least one of the hydraulic props is inclined towards the face-side of the unit and engages the roof shield. At least one of the hydraulic props is inclined towards the goaf-side of the unit and engages the roof shield.