Abstract: A manifold for a borehole miner, wherein the manifold is rigidly secured to a first and a second pipe of a pipe bundle; movably connected to at least one other pipe; and provided with a collimating nozzle unit associated with a deflector plate unit, such that a pressurized abrasive jet spray can be directed against the walls of a bore hole, and the back splash from the jet spray will be prevented from adversely affecting the pipes in the pipe bundle by the deflector plate unit.

Abstract: A rotatable end deflector for an abrasive water jet drill is provided. The end deflector includes two wear resistant plates which direct portions of the water jet in opposite forward directions. Preferably, the abrasive water jet drill includes a source of high pressure water and a high pressure water outlet from which a stream of water is expelled. A venturi device is provided adjacent the water outlet for creating a vacuum. A feed device feeds an abrasive particular material to the venturi device so that the abrasive material is entrained in the stream of water. Thereafter, the stream of water is collimated in a rotating tube which produces a rotating cylindrical water jet which is then deflected before it impinges on the rock to drill the rock. The abrasive material is preferably sand and the tube including the deflector is easily replaceable.

Abstract: An end deflector for an abrasive water jet slot cutter is provided. The end deflector includes two wear resistant plates which direct portions of the water jet upwardly and downwardly. Preferably, the abrasive water jet slot cutter includes a source of high pressure water and a high pressure water outlet from which a stream of water is expelled. A venturi device is provided adjacent the water outlet for creating a vacuum. A feed device feeds an abrasive particular material to the venturi device so that the abrasive material is entrained in the stream of water. Thereafter, the stream of water is collimated in a tube which produces a cylindrical water jet which is then deflected before it impinges on the rock to mine the rock. The abrasive material is preferably sand and the tube including the deflector is easily replaceable.