Studies on the Cutting Resistance of Rock

Abstract

A rotary bit penetrates into the rock along a helical path under the action of an axial thrust force and a rotary torque and the action of the cutting tip is one of planing. It seems reasonable to assume, therefore, that a study of the planing action of a tool on rock would reveal much information to rotary drilling or boring.Then, we have studied on the following problems using a rock planing apparatus which is able to measure horizontal and vertical component of cutting resistance of rock: 1) effect of depth of cut, 2) effect of number of free surface, 3) effect of width of cutting tip, 4) effect of wear of cutting tip, etc.