| 摘要 |
A diamond core drill bit ( 100 ) is disclosed. The drill bit has a right-circular cylindrical body ( 120 ) with at least one side lubrication hole ( 122 ) toward the bottom of the body and a plurality of parallel grooves ( 124 ) oriented in an axial direction at the bottom circumferential sidewall of the body. A cap ( 130 ) at the top of the cylindrical body ( 120 ) closes one end of the body. The cap has a central lubrication hole ( 134 ) and alternative embodiments have at least one core extraction hole ( 132 ). These holes extend through the cap to the interior of the body. A hollow drive shaft ( 140 ) is mated to the cap ( 130 ) over the central lubrication hole ( 134 ), such that a lubricant can flow through the hollow shaft and into the internal volume of the body and out a side lubrication hole ( 122 ). Diamond grit ( 160 ) is bonded around the bottom edge on a portion of the internal and external sidewall surfaces at the bottom circumferential edge of the body ( 120 ) in such a way that the diamond grit ( 160 ) is bonded over a portion of the axial height of the grooves ( 124 ).
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