Horizontal directional drilling loads for rock and stone drilling, drill-head rotates one way only so one rock face segment is loaded with higher pressure by the leading cutter than remainder of the face, drill has leading and main cutters

摘要

Circular segments of the rock face are loaded with differing pressure for directional purposes, the pressure on one segment at least to be zero or a negative value. The drill-head (4) rotates one way only so one rock face segment is loaded with higher pressure by the leading cutter than the remainder of the face. The drill has leading cutter and main cutters set back using leading cutter with a set back reaming cutter. high-pressure jets for drilling fluid are arranged asymmetrically. The drill-head has a striker (2) and a concave steering face for directional drilling.