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U.S. Department of Energy
Office of Scientific and Technical Information

Rotary drill bit

Patent ·
OSTI ID:5680103
A rotary drill bit includes a cutting face having a peripheral edge and a central recess. A plurality of fluid discharge nozzles are mounted in the cutting face. A plurality of cutter elements are mounted in the peripheral edge and in the recess to fracture an earthen core formed as the drill cuts through a formation. A plurality of lateral discharge passages extend radially through the bit body from said recess and extend longitudinally to the peripheral edge to form circumferential interruptions in the peripheral edge. A convex protrusion is disposed centrally at a longitudinally inner end of the recess and includes a convex deflecting surface arranged to contact and fracture the earthen core and deflect the cuttings to the lateral discharge passages. A ridge is disposed along a trailing edge of each of the discharge passages to retard the flow of drilling fluid into the associated discharge passage from an adjacent one of the nozzles, whereby such fluid is caused to flow across cutter elements located behind the ridge.
Assignee:
Strata Bit Corp.
Patent Number(s):
US 4538691
OSTI ID:
5680103
Country of Publication:
United States
Language:
English