Abstract: A distributed coal cutting device for a Longwall face of a coal mine includes coal cutting units, where each coal cutting unit includes one coal cutting machine and two hydraulic supports, the two hydraulic supports are arranged side by side, the arrangement direction of the two hydraulic supports is parallel to the coal wall of the Longwall face, and the coal cutting machine is connected with one of the hydraulic supports. According to the device, multiple coal cutting machines are used for simultaneously carrying out coal cutting operation, and single-point coal cutting is changed into multiple-point simultaneous coal cutting, so that the coal cutting production capacity and the production efficiency are greatly improved. The multiple coal cutting machines can derive multiple control modes, so that the production flexibility and adaptability are improved.

Abstract: A roof support includes a base, a canopy for engaging a mine surface, a shield coupled to the canopy, and a link coupled between the base and the shield. The canopy is supported relative to the base and includes an end configured to be spaced apart from a mine face by a distance. The link is movable between a first position and a second position, and movement of the link between the first position and the second position causing the distance to change.

Abstract: An active temporary roof support apparatus for attachment to a mining machine includes at least one set of support members, each set including at least a first support member and a second support member for supporting the roof of an underground tunnel. A drive assembly is arranged to drive the set of support members, such that the first and second support members are sequentially moved for engaging the roof so that the roof is supported by at least one support member during an excavation operation of the mining machine. A mining machine and a corresponding method is also provided.

Abstract: A shield support assembly for underground mining includes a shield canopy and at least one floor runner as supporting surface elements. The shield canopy and at least one runner are connected in an articulated manner and can be pressed against rock at least one hydraulic cylinder which is supported in bearing pans on the shield canopy and floor runner. Each surface supporting element includes a welded construction of welded-together components. In order to be able to support higher forces without increasing the overall weight, at least one of the supporting surface elements includes at least one hollow metal box profile filled with a solid as a component of the welded construction.

Abstract: A roof support having a stabilizing-guiding system for two spaced articulated quadrilateral linkages joined by a spacer element. The stabilizing-guiding system includes two coordinating links respectively, pivotably connected at one of the ends thereof to the canopy and the bottom sprag and at their other ends the links are connected together by a connecting element. The connecting element is supported in a guideway fixed to the spacer element. Hydraulic legs are connected to the bottom sprag rearwardly of a plane bounding a walkway space for the crew on the bottom sprag.

Abstract: A yield valve comprises a valve body, a first inlet port, an outlet port, a valve seat, and a valve member movable between a first position in which it cooperates with the valve seat to prevent fluid communication between the inlet port and the outlet port and a second position in which the outlet port is brought into fluid communication with the inlet port. One side of the valve member is subjected to the pressure of fluid at the inlet port to urge the valve member towards its second position. Spring means acts on the other side of the valve member to urge the valve member towards its first position. The valve also has a valve chamber isolated from the inlet port and from the outlet port and a second inlet port for supplying a fluid under pressure to the chamber.

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 mine roof support comprises a canopy, a base section, hydraulic props for raising and lowering the canopy relative to the base section, a hydraulic valve for supplying hydraulic fluid under pressure to the props via a check valve, and a yield valve connected across the check valve. The yield valve has a valve member movable between a first position in which it co-operates with a valve seat to prevent the release of fluid from the props via the yield valve and a second position in which fluid can be released from the props via the yield valve. One side of the valve member is subjected to fluid pressure downstream of the check valve to urge the valve member towards its second position and the other side of the valve member is acted upon by a spring device to urge the valve member towards its first 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: A mine roof support comprises a ground engageable base section, a canopy, a shield section pivotally connected at one end to one end of the canopy and at the other end to one or more members connected to the base section, and hydraulic props for raising and lowering the canopy relative to the base section. An opening is provided in the canopy and a door is mounted with respect to the canopy for pivotable movement between a first position in which it closes or substantially closes the opening in the canopy and a second position in which it is inclined downwards away from said one end and towards the other end of the canopy for guiding material which in use falls through the opening towards a conveyor located adjacent to a mine face being worked.

Abstract: A roof support employs an hydraulic piston and cylinder unit as an adjustment device between the goaf shield and the roof-engaging structure. The cylinder unit is mounted to the shield with the aid of a bearing body defining a cup receiving a spherical end of the cylinder. The body also has recesses accessible via offset openings in which journals projecting from the cylinder are located. Locking pieces detachably fitted to the shield block the openings to retain the journals therein yet permit easy assembly and dismantling of the unit.

Abstract: To increase the height of operation of a shield type roof support an attachment is fitted to the floor sill or to each of a pair of spaced-apart floor skids. The attachment has side walls with bores for receiving pivot pins used to link the attachment to the floor sill or skid and to guide levers connected to the goaf shield. A transverse body extends between the side walls and defines a socket for forming part of a ball-and-socket joint connecting the attachment to a hydraulic prop. The side walls of the attachment have under surfaces which rest on a support surface of the skid or sill near the working face.

Abstract: A self-advancing mine roof support comprising a floor engaging base 11, a roof engaging canopy 12, hydraulic jacks 19a, 19b to urge the base and canopy apart, and a linkage system located towards the rear of the support. The linkage system comprises an inclined shield member 22 pivotally connected to the canopy 12, and at least two links 23, 24 interconnecting the shield and the base. The jacks 19a, 19b, are located substantially halfway along the length of the base and extend substantially vertically from the base. There is a hydraulic jack 18 operable between the roof engaging canopy 12 and the linkage system to effectively counterbalance the projection on the canopy 12 which extends forwardly of the jacks 19a, 19b.

Abstract: A roof cap assembly of a roof support mechanism includes a main cap having extension bearing portions at its front end, a forward cap which is pivotally attached at its rear end to the extension bearing portions of the main cap, and two supporting cylinders connected between the main cap and the forward cap at spaced apart locations across their widths and so as not to extend therebelow. The supporting cylinders include a housing containing twin pistons and an adjustable pressure transmitter is provided for each supporting cylinder and is constructed to increase the pressure in the pressure chambers therein when the pressure of the pressure medium supplied thereto exceeds a minimum set value.

Abstract: A foot element of an adjustable roof support mechanism includes side walls that have aligned guide grooves in their facing surfaces and a spherical bearing surface in a floor portion therebetween. The guide grooves include inclined entry portions and enlarged terminal portions. A cooperable, extendable strut element includes a tubular body having a spherical lower end and two cams extending away from opposite sides near its lower end. The cams are shaped so as to fit within the guide grooves of the foot element. When attaching the strut element to the foot element the cams thereof are moved along the entry portions of the aligned guide grooves and into the terminal portions thereof. Thereafter, the strut is rotated into a use position. When in its use position, the cams cannot be removed from the terminal portions of the guide grooves, thus preventing unintentional separation of the strut element and the foot element.

Abstract: A mine roof support has gap seals in the form of L-shaped plates on its roof cap and goaf shield. The side walls of the plates overlap at the junctures between the roof cap and goaf shield and are connected with pivot connections each of which is composed of a pin inserted into apertures in the side walls of the plates. The pin has a peripheral groove at its inner end region which receives an arcuate yoke plate serving as a support. The yoke plate is itself detachably secured in place with a releasable rod permitting the pivot connection to be easily dismantled.

Abstract: A shield support, suitable for use in mines, comprising a floor-engaging structure which includes two sledge or like elements disposed side-by-side and spaced apart one from the other, a roof-engageable canopy, a shield mounted for pivotal movement with respect to the canopy and extendable and contractible prop means, carried by said elements, which are operable to adjust the height of the canopy. A pivotal guide linkage for supporting the shield from said elements includes links which are so connected to those elements and to the shield that the elements are rigidly coupled together only through the intermediary of those links and the shield.

Abstract: In a roof-shield support system employed in mines, at least two levelling rams each acting between a shield frame unit and an associated gap-seal plate, the latter being arranged so as to be slidable relative to the associated shield frame unit. Each levelling ram comprises a cylinder, piston and piston rod, is arranged so that the piston rod has a longitudinal bore which is open at the piston end of the piston rod, and an elongated rod which is sealed relative to the piston rod being disposed within said bore. The bore is in use in communication with a hydraulic fluid system of the ram and after levelling has occurred by actuation of the ram the pressurized hydraulic fluid admitted into the bore applies a force to the associated gap-seal plate so as to ensure its continuing tight engagement with the adjacent shield frame unit.

Abstract: A mine roof support has a roof engaging structure 13 and a floor engaging base 14, spaced apart by extensible hydraulic jack means 15 and 16. The roof engaging structure and the base are interconnected by a pivotal linkage device 23, 24 arranged so that, throughout its range of working movement, a pivot point of the linkage performs substantially greater movement in the vertical direction than in the horizontal direction. This reduces the effect of problems arising from the linkage device projecting substantially into the goaf area of a mine working or into the walkway area of the support. In a preferred embodiment the linkage device comprises a parallelogram type linkage.

Abstract: A mine roof support comprises a base formed of two base members, a beam disposed therebetween, jacks for lifting the base members or the beam one relative to the other and a jack for advancing the base member or the beam one relative to the other. A roofing bar structure is supported from the base members by extendible props and an elevated platform is disposed between the base and the roofing bar structure. The support is advanced by lifting, advancing and lowering the beam relative to the base members and then lifting, advancing and lowering the base members relative to the beam.

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 support for the roof in longwall mining operations includes a gob canopy at the rear of a roof canopy. The gob canopy can move about a vertical pivot and a horizontal pivot by operation of a hydraulic actuator. To stabilize the support, the gob canopy moves into or out of contact with the roof at the rear of the roof canopy. The actuators can move the gob canopy to the left or right side of the roof canopy about a vertical pivot so that a skeg member on the upper surface of the gob canopy drags along the mine roof for steering the roof support when it is advanced toward the mine face. Gaps between the gob canopies of side-by-side roof supports function in the manner of grizzly bars to permit recovery of small pieces of gob roof rock.

Abstract: Apparatus for controlling the cutting horizon of a mineral winning plough comprises means for pivoting the guide along which the plough moves. The guide is fixed to the face side of the conveyor, and said means acts on the goaf side of the conveyor. Said means comprises a plurality of control devices, each of which has an upstanding plate fixed to the goaf side of the conveyor, an abutment member pivotally connected to the base of the upstanding plate, and an actuator arranged between the abutment member and the upstanding plate. The actuators are effective to pivot the conveyor relative to the abutment members. Each actuator comprises a hydraulic ram and a toggle linkage which magnifies the working stroke of the ram.

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: The roof support according to the invention is between the roof-bar (2) and the sill piece (1) with at least one system of levers (3,4) connected by articulation with each other and connected by articulation with the roof-bar (2) and the sill piece (1) so that they have the form of a lying letter V directed with its vertex towards the fall. Between the levers (3,4) it is provided with the hydraulic cylinder (5) spragging the levers (3,4) and thus the lining. That admits to achieve a high multiplication of the cylinder travel in relation to the change of the lining height, and a multiplication of forces. In shield roof supports of a lemniscate type the lever system can consist of the fall shield (6) and the outside arm (7) of the lemniscate arrangement.

Abstract: A roof support for a mine gallery which extends at a relatively large angle to the horizontal comprises an upper, a middle and a lower roof support unit arranged adjacent each other and having each a pair of elongated transversely spaced skids rigidly connected by bridges to each other and engaging the sole of the inclined mine gallery. An abutment beam likewise engaging the sole is arranged inclined to the elongation of the skids adjacent to the face of the gallery to be mined and connected to the skids of the middle roof support unit by a pair of flat sole plates rigid with the beam and tiltable about horizontal axes with respect to the skids, whereas the upper and the lower roof support unit are connected to the beam by flat elongated sole engaging end members connected to the beam pivotable about vertical pivot axes. In this way ample space is provided beneath the roof of the mine gallery between the beam and the roof support units to permit mining of coal seams of small height.

Abstract: A portal building frame formed of asymmetrical metal sections comprises a roof frame member supported on columns by means of knee connectors which telescopically engage with the roof frame member at each end thereof and with the columns. The connectors are secured to the roof frame member and the columns by bolts through both the webs of the metal sections and through flanges thereof, the bolts through the webs being longitudinally spaced by a distance corresponding to the lateral dimension of the webs. The knee connectors are each fabricated with reinforcing plates on the flanges of the metal sections at the joint between the sections forming the connector, and a stiffening plate is welded between mitred ends of the sections to the webs, flanges and reinforcing plates to form the one-piece connector.

Abstract: A mine roof support has a roof-engaging frame structure supported by hydraulic props on a floor frame and pivotably linked to a goaf shield. The roof frame and goaf shield have L-shaped seal plates at their sides. The seal plates are subjected to a lateral-outwardly-biasing spring force by means of springs and push rods accommodated in guide bores in both the roof frame and goaf shield. To adjust the distance between the plates, there are piston and cylinder units and coupling rods likewise accommodated in guide bores in both the roof frame and goaf shield. The seal plates of the roof frame overlap with those of the goaf shield. The plates are reduced in thickness at their overlapping regions and are pivotably interconnected thereat to correspond to the pivotal connection between the roof frame and the goaf shield. To facilitate assembly in situ, detachable push-in pins are located in bores in the coupling rods and push rods and in lower transverse walls of both the roof frame and goaf-shield.

Abstract: A mine roof support has a base and a roof shield pivoted to the base and carrying at its upper end a pivoted cap which is urged upwardly against the mine roof by a hydraulic pit prop reacting between the cap and the base. The lower end of the roof shield is connected to the base by two links each having a pivot cooperating with a pivot on the roof shield, and a pivot cooperating with a pivot on the base. In addition, the base and/or the lower end of the roof shield has an auxiliary for each link and each link has an auxiliary pivot which can be connected with one of the auxiliary pivots of the base or lower end.

Abstract: A shield timbering frame for timbering mines adjacent a mining face, comprises a horizontal floor-engaging skid and a breaking shield extending obliquely over the skid which is connected to the skid by a pair of longitudinally spaced, lemniscate guide rods. A roof cap member has an inner end which is pivoted to the upper end of the breaking shield and it is also braced by a piston and cylinder combination which is articulated to the breaking shield intermediate the length thereof and to the roof cap intermediate its length. At least one hydraulic ram is mounted on the skid and is engaged with the roof cap between the connection of the roof cap to the breaking shield and the connection to the additional support. The hydraulic ram is madeup of at least three telescopically interengageable extensible and retractable parts and includes pressure valve means to provide a substantially equal support pressure on the roof cap in various positional orientations of the roof cap.

Abstract: A shield type support for use in underground mining comprises a floor construction with one or more pressure operated extensible and retractable rams mounted on the floor and connected at their upper end to a roof-member. The roof-member is articulated at one end to a breaking shield which has an opposite end which is supported by lemniscate guide rods. The lemniscate guide rods are carried on a support which is mounted for adjustable movement on a column supported on the floor. In addition, this support also advantageously carries an additional adjusting element in the form of a telescopically retractable and extensible ram connected between the support and the roof structure at a spaced location from the other rams.

Abstract: In a mine roof support in which a roof shield, pressed by hydraulically operated, collapsable and extensible props, arranged between the roof shield and a sole plate, against the roof of a mine gallery, is connected at its rear end to a rear shield, which in turn is connected by links to the rear end of the sole plate and in which a hydraulically operated cylinder-and-piston unit is interconnected between the roof shield and the rear shield for controlling the included angle between these shields, an arrangement for stopping further feeding of pressure fluid into the props when the inclined angle between the shield reaches a predetermined minimum or maximum angle.

Abstract: A coupling gear for connecting two side-by-side, longitudinally extending shiftable skids of a divided footwall skid of a lemniscate shield timbering frame for actuation by a fluid pressure operated piston and cylinder combination which is adapted to be connected thereto, comprises, a double crank joint which includes first and second outer crank pins extending transversely between the skids with bracket means adapted to be positioned on the respective skids for rotatably supporting the outer crank pins on the respective skids and, wherein, the crank pins have outer ends rotatably supported in the bracket means and opposite inner ends and including first and second longitudinally extending, substantially parallel crank arms, one of which has a first end connected to the inner end of the first outer crank pin and the other of which has a first end freely rotatable on the second outer crank pin and with a central crank pin having a first end freely rotatable in the first crank pin arm opposite end and an opposi

Abstract: A canopy and shield structure for supporting a shield adjacent a working face in a seam-like mine deposit, comprises a floor skid which is connected through an extensible and contractable prop at the working face end to the working face end of a canopy adapted to be positioned in parallel relation to the roof strata. The working space is covered at the waste removal end by a shield which includes a lower two-arm lever portion which is pivotally mounted on the skid and an upper portion which is pivotally connected to the longer arm of the two-arm lever adjacent the upper end thereof and is also pivotally connected to the canopy. The two-arm lever is driven by a hydraulic drive motor and a parallel linkage is connected between the upper shield part and the canopy in order to provide a guidance of the canopy in a direction substantially perpendicular to the strata.