| 摘要 |
A rotary bit having diamond cutting elements in its drilling face for drilling a bore hole, drilling fluid being pumped from the bit and into primary feeder waterways in the drilling face extending to the outer gauge portion of the bit. Jet passages receive drilling fluid from the interior of the bit, discharging such fluid into secondary waterways in the drilling face in the direction of rotation of the bit and toward the outer gauge portion, to create low pressure regions in the secondary waterways and cause fluid to flow from the relatively high pressure feeder waterways across the intervening bit faces toward the secondary waterways, effecting a cleaning action of the cuttings from the bottom of the hole, the bit faces and the diamonds embedded therein, such cuttings being flushed upwardly around the bit toward the top of the bore hole.
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