Abstract: A cutting device for a mining or tunnelling machine takes the form of a roller with cutter bits which rotates at the end of a movable arm as is known. Grooves in the roller receive plate-like components which support water spray nozzles radially within the extremities of the cutter bits. The support components are stationary but are adjustable about the axis of rotation of the roller to bring the nozzles into the appropriate location during operation.

Abstract: Tunnel driving apparatus employs a hollow support tube positioned axially centrally inside a drive shield. An inner cutting machine is supported and positioned inside the support tube and serves to cut away a central region of a working face. Outer cutting machines are also supported by the support tube but on the exterior thereof. The outer cutting machines serve to cut away the outer region of the working face. The cutting machines may each have a pivotable arm carrying cutting drums and are supported and guided for axial and rotary motion relative to the support tube.

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 machine is disclosed which is for use in mining or tunnelling work and employs a beam or arm supporting cutting means and connected through a support structure to a turntable carried by a movable chassis. The turntable is adjustably rotatable about a vertical axis and one or more piston and cylinder units are provided to raise or lower the arm in relation to the support structure. This structure is itself adjustably pivotable in relation to the turntable about a further axis which is generally aligned with the horizontal forward position of the arm i.e. in the direction of advancement of the mining or tunnelling work. In addition part of the structure connected to the arm is also displaceable along this further axis so that the cutting means located at the free end of the arm can be adjusted in respect of a variety of directions. The cutting means is itself composed of cutter rollers driven to rotate about an axis extending laterally of the arm.