| 摘要 |
<p>This invention relates to an improved rock or earth penetrating device and method that applies to drilling bits, tunnel boring machines, or micro-tunneling, and block cutting devices. The disclosed invention takes advantage of the fact that the tensile strength of a rock is significantly lower than its compressive strength. The invention combines abrasive rock/earth cutting with direct tension rock/earth cutting. First, narrow grooves or kerfs (16) are cut into the rock/earth by circular cutting elements (103). Next, rolling elements (101) roll inside the kerfs (16) providing normal forces against the kerf walls (19). The ridges (18) between adjacent kerfs are broken under the tensile stresses induced by these normal forces. The wastes produced during cutting are flushed away with a cooling or drilling fluid. The embodiments of the novel drill bit are described: the first one relates to the destructive drilling of a borehole; the second one relates to a core bit used to obtain an intact core sample; and the third relates to the extraction of large blocks of stone from quarries.</p> |
