Drill bit assembly
A drill bit assembly is described comprising: a pilot bit comprising: a bit body having two legs radially positioned 120/sup 0/ apart thereon and depending from the lower surface thereof, the lower surface of the bit body away from the legs being beveled to reduce the effective area of the lower surface; a cutter cone rotatably mounted on each of the legs and extending inward and downward whereby the inner tip of each cone lies on the centerline of the body; a first reamer section comprising: a reamer body connected to the upper end of the pilot bit; two disk cutters; and means for rotatable mounting the disk cutters on the body at points radially spaced 120/sup 0/ from each other and positioned to drill a hole having a diameter larger than that of the hole drilled by the pilot bit.
- Assignee:
- Four E Inc., Lafayette, LA
- Patent Number(s):
- US 4706765
- OSTI ID:
- 5863463
- Country of Publication:
- United States
- Language:
- English
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