| 摘要 |
<p>A polycrystalline diamond cutting element in an earth boring bit is affixed to the bit face by an improved tooth. The tooth includes a prepad extending from the face of the mining bit contiguous to and substantially congruous with that portion of a polycrystalline diamond element also extending from the bit face. A trailing support is provided behind the polycrystalline diamond element and is similarly contiguous and substantially congruous therewith so that a generally singular geometrically shaped body is formed by the prepad, the polycrystalline diamond element and the trailing support. The prepad and trailing support are integrally formed from the matrix material of the rotary bit and are generally arcuate about a radius centered on the bit face. The polycrystalline diamond element is thus securely retained on the bit face while exposing a maximum extent of the polycrystalline diamond element sandwiched between the prepad and trailing support.</p> |
