Abstract: The invention relates to novel dendritic molecules and methods of making them. The dendritic molecules comprise arms, each of which arms is a polymer. The dendritic molecules can be synthesised by way of a reasonably small number of versatile and reliable step-wise reactions, especially click chemistry reactions. Chemical and structural heterogeneity is possible in the dendritic molecule. The invention also provides for surface and interior functionalisation of the molecule.

Abstract: Mining equipment for steering the cutting horizon of a mining machine cutter which is mounted on a ranging arm and which in use makes repeated traverses along the working face, comprises a boom urged into contact with the mine roof formed on a previous traverse of the machine. The boom is urged towards the mine roof by a ram hydraulically connected to a piston and cylinder device such that movement of the piston of the device is in accordance with that of the ram. Movement of the piston rod activates a flow control valve controlling operation of a ram controlling ranging of the arm.

Abstract: A holder assembly for a sensitized cutter tool on a cutter head of a mining machine, comprises an outer component mountable on the cutter head and defining a recess and an inner component engageable within the recess by movement in at least one direction, the inner component providing holder means for the sensitized cutter tool, the outer component defining an abutment face within the recess for engagement by a corresponding abutment face defined by the inner component, the abutment faces being inclined to said at least one direction of movement.

Abstract: A holder assembly for a sensitized cutter tool mountable on a cutter head of a mining machine comprises a holder adapted to hold the tool. The holder is pivotal supported abutting a mounting sensor means provided to sense cutting reaction on the tool, the cutting reaction tending to urge the holder to pivot about the mounting.