Rock drill diamond and carbide cutting tip arrangement - has different cutting zones to ensure fine grinding of cut material

摘要

A rock drill has three equally spaced roller cutters (41) with their axes of rotation sloping towards the middle and ahead of the cutting head. Each cutter has rings of carbide cutting tips (42) and the dia. of the head (40) is greater than the dia. of the path of the outermost rings of carbide tips. This leaves room for sets of diamond cutters (43) rotating around a circular path which also has a greater dia. than that of the outermost carbide tips. Between each pair of roller cutters is a hole (44) for discharge of drilling fluid. Alternative cutting tip arrangements are designed so that material cut by the diamond tip is ground up finely by the carbide tips.