Abstract: A mineral mining installation has a longwall conveyor provided with a guide at the face-side thereof. A drive frame is provided at each end of the conveyor, and a plough is movable along the guide to win material from the longwall face. The plough is driven by a chain passing round a pair of end sprockets associated with the drive frames. The plough is constituted by a pair of plough bodies joined together by an intermediate member pivotally connected therebetween. Each of the plough bodies is provided with cutter bits and the intermediate member may also have cutter bits. The two ends of the plough driving chain are connected to the intermediate member, and the plough is of sufficient length to enable material to be won at least as far as each end sprocket.

Abstract: Connection means for connecting two adjacent channel sections of a scraper-chain conveyor comprises two coupling elements fastened to the outer sides of the adjacent ends of the channel sections, and a coupling member for connecting the two coupling elements. The coupling member has a shank provided at each end with an enlarged head portion. The coupling elements are provided with laterally open recesses for receiving, with a predetermined amount of axial play, the coupling member. One of the coupling elements is provided with a projection which mates, with an all-round clearance, with a recess in the other coupling element. One head portion of the coupling member is provided with an axially extending locking member which extends behind a complementary locking member fastened to one of the channel sections. The other head portion of the coupling member is provided with at least one locking projection which co-operates with a corresponding locking recess in the adjacent coupling element.

Abstract: The drive members of a drive shield, which are mounted side-by-side for longitudinal displacement as is known per se, are provided with seals or packings to close off the gaps between adjacent members. Each seal or packing is composed of two flexible resilient parts joined to respective drive members. The seal parts slidably engage one another in sealing fashion. The parts of the seal may be of the same or disimilar shape but at least one of the parts is hollow with an interior cavity which can receive pressure medium used to expand the part to urge the contacting surfaces of the parts into close sealing contact. Lubrication between the contacting surfaces to permit sliding can be achieved by employing a suitable lubricating agent as, or in, the pressure medium and by allowing some of the pressure medium to pass from the interior cavity to the contacting surfaces.

Abstract: A mineral mining installation has a conveyor and a plough movable along a guide provided at the face side of the conveyor. An auxiliary winning machine constituted by a cutter drum mounted on a carrier by means of a pivotal jib, is provided for winning material in the "stable-hole" region. The carrier is movable along an auxiliary guide which is an extension of the plough guide. The carrier is provided with a drivable pinion which meshes with a rack on the auxiliary guide for driving the auxiliary winning machine along the auxiliary guide.

Abstract: A cutter bit for use with a cutting or winning machine has a generally cylindrical shank and a generally conical cutting head. The shank is rotatably received, in use, within a matched bore in a bit holder. The shank is formed with a reduced-diameter portion on which is rotatably mounted a bearing ring. A compressible locking ring surrounds and grips the bearing ring so that, in use, the locking ring frictionally engages the bore in the bit holder so as to restrain relative axial movement between the cutter bit and the holder.

Abstract: A multi-core duct is constituted by a plurality of resilient conduits bunched together within a protective sleeve. Each of the conduits is formed from a high-strength synthetic plastics material and the protective sleeve is made of a flame-resistant synthetic plastics material.

Abstract: Shield apparatus for tunnelling comprises a framework supporting drive members advanced individually or in groups as known per se. The framework and its drive members are carried by a pair of elongate floor beams arranged at the sides of the tunnel wall. Each floor beam has a longitudinal slot or groove therein which is open to the rear end of the beam. This slot or groove receives anchoring pins fitted in situ into the floor of the tunnel working so that the beams can slide along the pins in the direction of advancement.

Abstract: Apparatus for driving and lining tunnels utilizes a knife shield for driving a tunnel and shuttering for forming a concrete lining behind the knife shield. The shuttering is constituted by a plurality of shuttering elements, each of which is connected to, and inwardly off-set from, a respective knife. The shuttering elements are, therefore, advanced together with their knives and concrete is forced into the space between a shuttering element and the tunnel wall as that element is advanced.

Abstract: A drive shield for driving wide underground cavities comprises a plurality of knife shields arranged side-by-side transversely of the direction of advance. Each knife shield has a plurality of elongate knives displaceably mounted on a respective support frame. The elongate knives are advanceable relative to their support frame by means of hydraulic rams mounted on that support frame. The support frames of each pair of adjacent knife shields are linked by connecting means such as double-acting hydraulic rams, which permit one of the support frames to be advanced relative to the other.

Abstract: A scraper-chain conveyor is composed of a series of channel sections arranged end-to-end with shaped components on one side defining a guide for a machine such as a plough. Each component has a tubular track or rail at its upper end and these rails are spaced apart to receive coupling devices. Each device has a cylindrical body matching the rail profile and located between adjacent rails. Spigots engage with clearance in these rails; one spigot being integral with the body and the other spigot being slidable within the body so as to retract or extend therefrom. A recess in the body receives a block which is detachably secured to the body to prevent the slidable spigot from retracting.

Abstract: A tunnel drive shield is provided with a plurality of bracing units spaced around its periphery. The bracing units are expansible against the surrounding tunnel wall to control the direction of shield advance. A bracing unit is provided in each of the four shield quadrants defined by the vertical and horizontal center planes of the shield. Each of the bracing units is expansible in a non-radial direction.

Abstract: A mine roof support unit comprises a floor sill, a roof cap, a goaf shield and hydraulic props supporting the roof cap above the floor sill. The goaf shield is pivotably connected to both the floor sill and the roof cap. The floor sill is provided with at least one auxiliary prop which is arranged to contact and support the roof cap only when the hydraulic props have been retracted by a predetermined amount.

Abstract: Apparatus for driving tunnels or the like employs a drive shield known per se, with drive members supported and guided on a frame. Rear extension members are linked to the drive members, preferably through units permitting relative displacement therebetween and these rear members form a rear shield for receiving supports and reinforcements for a permanent lining for the tunnel. A concrete spraying nozzle or the like applies a strip of concrete to the tunnel wall each time a rear member is shifted in the advancing direction. In this way a series of strips, preferably shape locked together at their ends, can be built up stage by stage to create the lining.

Abstract: Apparatus for use in tunnel driving employs a drive shield of known type with elongate drive members arranged side-by-side and supported and guided by a rigid frame. Hydraulic rams are used to alternately advance individual members or groups of members and the frame. Fluid concrete is introduced behind the shield to form a permanent lining supported by formwork and sealed to the tunnel wall by sheet material. The fluid concrete is contacted during its setting period by a hollow ring member of the formwork. The ring member is provided with a filter structure permitting water to be withdrawn by suction. Further separate hydraulic rams interconnect the ring member and the frame of the drive shield enabling the fluid concrete to be compressed. Some of the drive members have prolonged thin rear extensions which form tails extending partly around the concreting zone in contact with the tunnel wall.

Abstract: A coal plough has a main body guided for movement back and forth along a longwall coal face. The body supports various cutting tool carriers which are adjustable with the aid of hydraulic piston and cylinder units. Fluid is supplied to these units by means of a flexible composite line which also conveys control signals remotely initiated for selecting the units to be charged with fluid to effect the adjustment desired.

Abstract: In a mineral mining installation employing a series of shifting rams for advancing a scraper-chain conveyor provided with a guide for a mining machine, a control system is used to provide a succession of small fluid doses to the rams. Control signals, preferably remotely generated, serve to actuate local valves to cause a selected one or group of piston and cylinder metering devices to alternately accept and expel pressure fluid from a working chamber. In this way a pre-determined volume of pressure fluid can be transferred to one or more of the rams to effect the shifting advancement. This volume of pressure fluid is made up from a succession of small fluid doses each a small fraction of the desired shifting distance so that by repeated cycles of the device or devices the ram or rams associated therewith can extend in fine defined increments.

Abstract: A scraper unit for a scraper-chain assembly is composed of a one-piece scraper with extensions at the ends of its main body for engagement with horizontal links of the chains. The extensions have underside recesses which locate the shanks of the horizontal links and external cavities which locate the vertical links joined to these horizontal links. Deep vertical profiled pockets in the scraper end regions receive and shape-lock coupling pieces which encompass the inner shanks of the horizontal links and project laterally across the links, i.e., parallel to the scraper. The coupling pieces can be permanently joined to the links or detachable therefrom. The coupling pieces have tongues which support beneath the outer shanks of the horizontal links. Nuts engage on fixing bolts or the like projecting through both the scraper and the coupling pieces enabling the scraper to be detached. Where the coupling pieces are detachable they have additional threaded pins engaging in bores in the scraper and receiving nuts.

Abstract: A mineral mining installation employs a scraper-chain conveyor with a guide at the mineral-face side supporting a main machine, such as a plough, driven back-and-forth along a mineral face by a chain disposed at the mineral-face side of the conveyor. A further chain drive is arranged at the opposite side of the conveyor and is drivably coupled to an arm projecting over the conveyor and connecting with a further plough body. The further plough body is either supported together with the arm on further guides so that it can be driven back and forth along the face above the main machine or else the further plough body is supported directly on the main machine with its arm guided at the opposite side of the conveyor. Releasable coupling devices enable the further plough body to be connected to the main machine.

Abstract: A guide for a mineral winning or loading machine, such as a coal plough, is composed of assemblies secured to the mineral face side of a conveyor. The assemblies have angle plates with upstanding wall portions securable to the side walls of the conveyor and integral foot portions supporting the machine and resting on the floor of the mine working. Spacers separating upper and lower passages for guiding a drive chain are in turn secured to the wall portions of the angle plates and these passages are shielded by cover plates formed with ramp-like inclined guide surfaces for the machine. The cover plates are pivoted to the spacers at their lower regions so that they can be pivoted outwards to allow access to the passages therebehind. The cover plates are locked with releasable devices to the wall portions in their closed position and have recesses accommodating the spacers which have inclined surfaces forming continuations of the guide surfaces of the cover plates.

Abstract: A system for controlling the thrust applied to a mineral winning machine, which is movable along a guide at a longwall face in a mine working, includes control means which regulates the thrust applied to the guide by hydraulic rams in dependence upon the loading of the winning machine drive. The control means may include one pressure regulator for each ram, one pressure regulator for each of a plurality of groups of rams, or one pressure regulator for all the rams.