| (19) |
 |
|
(11) |
EP 0 325 272 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
07.02.1990 Bulletin 1990/06 |
| (43) |
Date of publication A2: |
|
26.07.1989 Bulletin 1989/30 |
| (22) |
Date of filing: 20.01.1989 |
|
|
| (84) |
Designated Contracting States: |
|
BE DE FR GB NL |
| (30) |
Priority: |
20.01.1988 US 146290
|
| (71) |
Applicant: Eastman Teleco Company |
|
Houston, Texas 77032-1925 (US) |
|
| (72) |
Inventors: |
|
- Tibbitts, Gordon A.
Salt Lake City
Utah, 84117 (US)
- Jones, Mark L.
Midvale
Utah, 84047 (US)
|
| (74) |
Representative: Busse & Busse
Patentanwälte |
|
Postfach 12 26
49002 Osnabrück
49002 Osnabrück (DE) |
|
| |
|
| (54) |
Drill bit with improved steerability |
(57) A drill bit offering improved steerability. Drill bits include gage sections which
are adapted to facilitate deflection of the bits within a borehole to facilitate navigational
or directional drilling. The gage portions of the bit may be arranged in an arcuate
path around a portion of the periphery of the bit. Also, the bit portions may be spaced
and adapted to serve, at least in part, as fulcrums, to facilitate deflection of the
bit and the bringing of gage cutting portions of the bit in contact with the sidewalls
of the borehole.