Abstract: A drill head including: an elongate housing, a first end of the housing being coupled to an end of a drill pipe in use; a base at a second end of the housing, one or more drill cutters being attached to the base; a supply passageway at least partially within the housing, the supply passageway being supplied with a flow of gas in use; a return passageway at least partially within the housing, a first end of the return passageway being connected to an end of an inner tube extending inside the drill pipe in use, and a second end of the return passageway forming an opening in the base proximate to the one or more drill cutters; and one or more ports for directing at least some of the flow of gas from the supply passageway into the return passageway in a flow direction extending away from the base and towards the inner tube, to thereby cause loose material to be drawn into the return passageway through the opening and transported away from the drill head via the inner tube in use.

Abstract: A drill head including: an elongate housing, a first end of the housing being coupled to an end of a drill pipe in use; a base at a second end of the housing, one or more drill cutters being attached to the base; a supply passageway at least partially within the housing, the supply passageway being supplied with a flow of gas in use; a return passageway at least partially within the housing, a first end of the return passageway being connected to an end of an inner tube extending inside the drill pipe in use, and a second end of the return passageway forming an opening in the base proximate to the one or more drill cutters; and one or more ports for directing at least some of the flow of gas from the supply passageway into the return passageway in a flow direction extending away from the base and towards the inner tube, to thereby cause loose material to be drawn into the return passageway through the opening and transported away from the drill head via the inner tube in use.