| 发明名称 |
Rotary drill bit |
| 摘要 |
A rotary drill bit includes cutters arranged in a series of concentric rings, the cutters of one of the rings having a different wear resistance to the cutters of another of the rings with the result that the stability of the drill bit improves with wear. Although the wear resistance is different, the cutters have substantially the same impact toughness.
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| 申请公布号 |
US2002033282(A1) |
申请公布日期 |
2002.03.21 |
| 申请号 |
US20010682471 |
申请日期 |
2001.09.06 |
| 申请人 |
GRIFFIN NIGEL DENNIS;HUGHES PETER RAYMOND;MATTHIAS TERRY R. |
发明人 |
GRIFFIN NIGEL DENNIS;HUGHES PETER RAYMOND;MATTHIAS TERRY R. |
| 分类号 |
B22F7/06;B23B27/14;C04B35/52;C04B37/02;C04B41/45;C04B41/53;C04B41/81;C04B41/91;E21B7/06;E21B7/18;E21B10/00;E21B10/42;E21B10/43;E21B10/56;E21B10/567;E21B10/573;E21B10/60;E21B21/10;F16C33/04;(IPC1-7):E21B10/46 |
主分类号 |
B22F7/06 |
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