Abstract: A cutter bit assembly for a mining or tunnelling machine has a cutter shank detachably fitted into a socket of a holder. To secure the shank in position a piston is displaced to cause pressure fluid to flow into a working chamber and act on a piston at one end of a rod-like securing element. The element is forced against a surface of the shank to urge the shank about a pivot and this in turn thrusts rear support surfaces of the cutter and the holder together. To release the cutter the pressure fluid is relieved and spring force displaces the securing element away from the shank. In this released condition, the cutter can be swivelled about the pivot and withdrawn from the socket.

Abstract: A floor cutter for a plough has a component provided with cutting edges fixed by welding to a main body locating in a holder. The components are connected together with step-like surfaces chamfered at the external faces of the components to faciliate the welding. Superimposed support surfaces extend more or less normally to other surfaces and permit adjustment of the position of the components during welding to vary the set cutting depth.

Abstract: A cutter-bit assembly employs an arcuate wedge to secure a cutter-bit within a pocket of a holder. The wedge fits into a tapered gap between complementary curved surfaces of the holder and the cutter-bit shank. A projecting insert carried by the shank mates with a serrated portion on the wedge. Contact is established between the wedge and the curved surfaces of the holder and the shank over outer regions separated by non-contacting clearances.

Abstract: A floor cutter bit for a coal plough has a body carrying a pair of hard metal plates which define a coal face cutting edge and a floor cutting edge. A hard metal pin locates between the plates and receives end zones of the plates within recesses.

Abstract: A cutter-bit assembly employs an arcuate wedge 16 to secure a cutter-bit 2 within a pocket 4 of a holder 1. An additional deformable insert or resilient backing piece 18 is also located in an arcuate gap between the cutter-bit shank and a curved surface of the holder. The insert or backing piece co-operates with teeth 19 to lock the wedge in position.

Abstract: A coal plough has an elongate plough body which is provided with cutters at each end. The plough body is supported at each of its two ends, by a flat narrow skid on a plate of a plough guide. The skids constitute wear-resistant members and are connected to the plough body in a readily replaceable manner. The skids are so shaped that they guide the plough in the lower zone of the plough guide, and establish connection between the plough and the plough drive chain.

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: 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: Apparatus for controlling the position of a mineral winning machine, such as a plough, movable along a guide at the mineral face side of a scraper-chain conveyor employs a connector bracket at the goaf side of the conveyor to which a floor-engaging skid plate is pivotably linked. A beam extends from a roof support and is also pivotably connected to the skid plate remote from the conveyor. A pair of piston and cylinder units are pivotably connected at their upper ends to the bracket. One of the units is pivotably connected to the skid plate and the other is pivotably connected to the beam. By operating the units together the skid plate can be held against the floor over part or all of its lower face while the conveyor goaf side is raised or lowered accordingly.

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: A mineral mining installation comprises a longwall scraper-chain conveyor, and a mineral winning plough. The plough is drivable to and fro along the face side of the conveyor by means of a plough drive chain and a three-part sword plate. The plough drive chain is housed in a chain guide attached to the goaf side of the conveyor. The sword plate is attached to the plough, and passes underneath the conveyor. Each pair of adjacent sword plate parts is detachable joined together by a pair of detachable pivot joints positioned respectively adjacent to the face and goaf sides of the conveyor.

Abstract: A mineral winning plough, such as a coal plough, has a plough body adapted to be moved to and fro alongside a mineral face on a plough guide. The plough body is provided with a pair of vertically-adjustable carriers, each of which is provided with floor cutters. The plough body is provided with setting means for raising and lowering the carriers into rest and working positions respectively. The setting means comprises a slide plate, and an intermediate member. The slide plate is mounted in an aperture in the plough body for limited movement relative thereto. The slide plate is attachable to a plough drive chain. The intermediate member forms a mechanical operative connection between the slide plate and the two carriers. The intermediate member is rotatably mounted on the plough body, and is positioned between the two carriers.

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 coupling device for connecting a mineral mining machine, such as a plough, to a drive chain. The coupling device is intended to locate within a channel inside a slotted guide containing the drive chain. The device is composed of coaxial tubular members secured together axially. The inner tubular member supports a swivel-mounted shackle connecting with the chain and a rigidly-mounted shackle connecting with the machine. One or both tubular members are shaped or relieved at the end nearest the swivel shackle to provide a cleaning nose which forces dust or the like from the channel as the chain draws the machine along the guide. A lateral projection on the outer tubular member engages in the slot and co-operates with the nose to guide the material away through the slot.

Abstract: A mineral mining plough has a plough body provided with a carrier supporting roof-level cutters. The carrier is movable vertically with respect to the plough body so as to adjust the cutting level of the roof-level cutters. A worm mounted on the plough body and a toothed rack attached to the carrier constitute means for adjusting the vertical position of the carrier, the worm meshing with the toothed rack.

Abstract: A coal plough which is movable to and fro in a mine working alongside a coal face, has floor-level cutters mounted on a carrier. The carrier is pivotable in a vertical plane about a horizontal axis perpendicular to the coal face. The carrier is pivotable between a working position, in which it bears against a first stop, and a non-working position, in which it bears against a second stop. The cutters bear against the floor of the working when the carrier is in the working position and are lifted clear of the floor when the carrier is in the non-working position. The first stop defines the level of cut of the cutters, and the second stop limits the upward pivotal movement of the carrier. The first and second stops are provided on the plough.

Abstract: A plough for winning material from a mineral face comprises two plough bodies connected together in a tension-proof manner. The two plough bodies are provided with detachable cutters at each end thereof. A rigid beam, also provided with detachable cutters, connects the two plough bodies at a predetermined height. The beam carries a plough upper part for each of the two plough bodies. Each plough upper part is provided with detachable cutters and is pivotably mounted on the beam by means of a parallelogram linkage. Each plough upper part is guided and supported on the beam by means of a keyed connection.

Abstract: A cutter bit assembly is composed of a carrier or holder secured or integral with a coal plough and a cutter part detachably secured to the holder. The holder has a head piece with opposite plane faces extending transversally to the cutting direction. A bore in the head piece opens to these faces and extends parallel to the cutting direction. The cutter part has a plane face engageable on one of the transverse faces of the head piece and a projection and recess on these engageable faces prevents rotation of the cutter part. A threaded member either integral with or separate from the cutter part extends through the bore in the head piece and receives a nut bearing on the other of the transverse faces and used to detachably secure the cutter part to the head piece.

Abstract: A coal plough is composed of two spaced-apart interconnected bodies which engage on a guide and which are moved along the guide to strip coal from a coal face. Each body is provided with various sets of cutter bits located at both its end regions and a floor cutter adjustable to control the height of cutting. The cutter bits at the inner face end regions of the bodies project further outwards towards the coal face than the other bits. During operation when the bodies move in one direction along the guide, cutter bits at the forward outer end region of the leading body cut into the coal face and the following-up cutter bits at the forward inner end region of the lagging body also cut into the face. The remaining cutter bits do not engage on the coal face.In this way the cutting operation is performed by both bodies and similarly both bodies can assist into transferring the coal detached from the face over the guide and into a scraper-chain conveyor.