Abstract: Tunnel driving apparatus incorporates a cutter shield with a plurality of drive members or cutters arranged side-by-side in a cylindrical array. The drive members are supported and guided for individual longitudinal displacement on a cylindrical continuous cowl or casing forming at least part of a support frame. Rams which serve to shift the drive members and the frame are coupled therebetween and extend through sealed openings in an end wall of a recess formed on the exterior of the cowl and open towards the drive members.To facilitate the creation of a concrete lining for the tunnel behind the cutter shield, a rear shield is formed by reduced rearwardly extending tails of the drive members. A further cylindrical casing locates within the rear shield and supports a pair of annular rings. One of these rings combines with a sheathing extending inside the further casing and the rear shield to form a concrete reception space.

Abstract: A hydraulic control system, particularly for controlling the operation of roof support props of a mine working, employs control devices operated manually to feed pressure fluid to the working chambers of the props to effect extension or retraction thereof. A two-state valve device is operated when the props are extended to ensure that the correct setting pressure is established. This valve device has a control piston which is actuated to cause the device to establish independent connection between the main fluid pressure line and the associated working chambers of the props charged with fluid by the initial operation of the control devices. The connection established by the valve device is maintained even if the control devices break connection between the chambers and the pressure line. When the correct setting pressure is reached, a further control piston of the valve device is actuated to break the connection established by the valve device ready for the next operative cycle.

Abstract: A hydraulic control system serves to control the operation of hydraulic rams used to position and displace an annular member which delimits a concrete reception space disposed at the rear of a tunnel-driving apparatus. The system acts to compensate for irregular loading on the annular member to ensure the latter is drawn up behind a forward drive shield without twisting or tilting. The rams are divided into groups each connectible to its own pump unit and the system connects the chambers of the rams which reduce in volume as the member is drawn up to the pump units in a manner such that the latter act as brake motors to restrain the member against the concrete pressure differential on its rear side.

Abstract: The specification discloses a method of, and apparatus for, winning mineral material from the pillars left by the bord-and-pillar mining process. An arcuate longwall face, which may be convex or concave, is formed along a row of pillars. The mineral material in the pillars is won by mechanical winning means such as a plough, the pillars in each row being won in a non-uniform manner. Some of the mineral material won from the longwall face may be used to fill the stalls left between the pillars behind the longwall face.

Abstract: A guide for mineral winning machines is composed of assemblies secured to the mineral face side of a conveyor. The assemblies have angle plates secured to the side walls of the conveyor pans and structures, integral or otherwise, which provide spacers at least partly defining elongate upper and lower passages for accomodating a drive chain. Covers are detachably and pivotably mounted to the structures to close off the upper passage. The covers are provided with substantial flat upper surfaces which serves to support and guide a machine. An upper guide rail formed by ribs at the edges of the upper surfaces and a lower guide rail formed by webs or web plates on the structures serve to locate with guide means of a plough supported on the inclined walls of the angle plates and driven by the drive chain. Where the flat support surfaces are not needed, or otherwise in case of need, the covers can be removed or replaced by covers of different design.

Abstract: A mineral mining installation is provided for use in a steeply-inclined longwall working. The installation comprises a ladder-shaped support frame, and a plurality of roof support units. The support frame extends along the entire length of the longwall working, and has a pair of generally parallel longitudinal beams interconnected by a plurality of transverse beams. The roof support units are positioned between the longitudinal beams, and are supported on the transverse beam. Each of the longitudinal beams comprises a plurality of beam sections pivotably connected together end-to-end. The support frame comprises a plurality of detachably connected sub-frames, each of which comprises a respective transverse beam and a respective beam section of each of the longitudinal beams.

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 mineral mining installation comprises a longwall conveyor, a plough movable to and fro along a guide fixed to the face side of the longwall conveyor, and a drive station at one end of the longwall conveyor. The drive station includes a drive frame supporting drive means for driving the longwall conveyor. A support beam is provided at the goaf side of the drive station. The support beam extends substantially parallel to the drive frame. A floor plate extends beneath the drive frame. The goaf-side end portion of the floor plate is supported on the support beam by means of a lifting device, whereby the goaf-side end portion of the floor plate can be moved up and down relative to the support beam by the lifting device.

Abstract: A rotatable cutting drum of a mineral mining machine is supported by a pivotable arm and is operably associated with a blade or the like which is positionable to assist in loading mineral detached by the drum. The blade is carried on a ring-like support which is itself mounted for pivoting about the axis of the drum to position the blade. Apparatus serves to couple the blade and its support selectively to the drum when it is desired to re-position the blade so that the latter moves around the axis of rotation of the drum with the drum itself. The apparatus is composed of piston and cylinder units provided in the blade support. The piston rods of these units extend outwardly from either side of the blade support and carry first and second abutment or friction rings. These respective friction rings either couple the blade support to the arm supporting the drum or to the drum.

Abstract: A hydraulic coupling device is provided for connection to a multi-line hose constituted by a plurality of hydraulic conduits bunched together. The coupling device comprises a casing, a plurality of plug pins housed within the casing, and a retaining disc for holding the plug pins. The plug pins are each connectible to a respective conduit of the multi-line hose. Each of the plug pins has a circumferential groove, and the plug pins are held against axial movement in radial slots in the retaining disc. Each of the radial slots has a first portion whose width is greater than the maximum external diameter of the associated plug pin, and a second portion whose width is less than that of the maximum external diameter of the associated plug pin, but which is greater than the diameter of the circumferential groove in that plug pin.

Abstract: A hydraulic coupling device is provided for connection to a multi-line hose constituted by a plurality of hydraulic conduits bunched together. The coupling device comprises a casing, a plurality of plug pins housed within the casing, and a holder for holding the plug pins. The plug pins are each connectible to a respective conduit of the multi-line hose. The holder is constituted by at least two retaining discs, and each plug pin is provided with two circumferential grooves. The retaining discs are each provided with a respective aperture through which one of the plug pins passes. Portions of the retaining discs adjacent to the apertures can be tightly engaged within the grooves in the plug pins, by being radially displaced and/or rotated relative to one another. In this way, the plug pins are axially fixed relative to the retaining discs.

Abstract: A device for limiting the stroke of a hydraulic ram of mining apparatus employs a segmental stop which partly surrounds the piston rod of the ram. The stop locates between the cylinder of the ram and a head piece at the end of the piston rod. The cylinder of the ram makes contact with the stop during retraction of the ram thereby limiting the stroke of the ram. The stop is connected to the head piece via replaceable or adjustable pins. These pins permit the distance between the head piece and the stop element to be altered at will. The connection pins also enable the stop to be arranged to partly surround the piston rod periphery over different regions thereof.

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 hydraulic coupling device for connection to a multi-line hose including a plurality of hydraulic conduits bunched together comprises a casing, a plurality of plug pins housed within the casing, and a holder for holding the plug pins. The plug pins are each connectible to a respective conduit of the multi-line hose. Each of the plug pins has a circumferential groove, and the thickness of the holder is greater than the width of the circumferential grooves in the plug pins. The plug pins are held in radial slots in the holder, the radial slots being so shaped as to retain the plug pins against axial movement with respect to the holder.

Abstract: A control unit/hydraulic control mechanism for controlling the hydraulic working appliances of a mine roof support unit has a control unit mounted on one side of a distributor plate, and a valve block mounted on the other side of the distributor plate. The distributor plate and the valve block constitute the hydraulic control mechanism, the valve block being constituted by a stack of pilot-operated hydraulic control valves. The control unit has a protective casing defining first and second chambers. The first chamber accomodates a plurality of electromagnetic valves. The second chamber constitutes a lead-through chamber for leading electric cables to the electromagnetic valves. The second chamber is provided with a respective socket for each of the electric cables.

Abstract: A floor cutter bit for a coal plough has a cutter body which supports a floor cutter plate and a coal-face cutter plate. The two cutter plates are made of hard metal, and have respective cutting edges. The cutter plates are soldered into respective apertures in the cutter body. The cutting edge of the floor cutter plate extends the entire length of the floor cutter plate, and the floor cutter plate extends over the entire width of the cutter body. The base of the coal-face cutter plate adjoins the upper side of the floor cutter plate thereby defining an L-shaped cutter plate configuration. The depth of the floor cutter plate, at least in the region where the two cutter plates meets, is greater than about 15 millimeters.

Abstract: A shearer-type mineral winning machine has rotatable cutting drums supported by swinging arms at the ends of its main body. High-pressure water emission nozzles are supported by adjustable carriers in positions generally adjacent the drums to effect preliminary cuts in a mineral face just in advance of the cutting drums.

Abstract: A shearer-type mineral winning machine has three-phase a.c. motors on its main body for driving cutting drums and for propelling the machine along a mineral face. The frequency of the a.c. power supplied to the motor which serves to move the machine is varied and controlled in dependence on the operation of the cutting drums. Electronic control means for monitoring the performance of the cutting drums and for controlling the frequency of the a.c. power supplied to the machine drive motor are located in a control station in a protected position in a gallery remote from the machine and power is supplied to the machine via cables and/or bus bars.

Abstract: A scraper-chain conveyor, for use in inclined mine workings, comprises a plurality of channel sections joined together end-to-end, and a scraper assembly. Each channel section has a pair of side walls interconnected by a floor plate. The scraper assembly comprises a plurality of scrapers connected to a drive chain. The side walls of the channel sections are shaped to define, together with the floor plates, three vertically-spaced, generally trapezoidal ducts. The uppermost and lowermost ducts provide guidance for the scrapers when the scrapers are respectively in their upper and lower runs. The middle ducts accommodate coupling members, such as toggle bolts, for connecting the channel sections together.

Abstract: A scraper-chain conveyor channel section or pan has side walls interconnected by a floor plate. The underside of the pan along which the lower run of a scraper-chain assembly runs is covered over by a bottom plate which is easily detached. To fasten the bottom plate in position use is made of one or more shaped lateral regions on the bottom plate which engage in an open pocket formed inside a guide provided on the mineral face side wall of the pan. The shaped region or regions and the pocket permit the bottom plate to be swung away from the undersurface of the pan at an angle to permit withdrawal from the pocket. Releasable tension springs hold the bottom plate against the undersurface of the pan.