Patent US4635738A successfully refreshed from Google Patents.
US4635738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill bit
Assignee: Baker Hughes Oilfield Operations LLC
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Filing: 1985-04-05
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Granted: 1987-01-13
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Expires: 2005-04-05
Abstract
Abstract A drill bit for drilling bore holes in underground formations comprising a bit body with a connecting spigot for connecting to a drill string or the like, and a cutting head which comprises a circumferential face extending parallel to its longitudinal axis and an end face having a drilling axis which is aligned with the axis of the connecting spigot. The drilling axis is parallel to and is offset relative to the axis of the cutting head. It is preferred that the end face is, at least in part, conical in shape.
Inventors
- 👤 Hans Schillinger
- 👤 Klaus Pahlke
- 👤 Siegfried Starke
- 👤 Heinz-Juergen Panhorst
- 👤 Hans-Eckhard Mengel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:59
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/64; E21B10/66; E21B10/26; E21B10/265; E21B10/46; E21B7/00; E21B7/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
93 words
A drill bit for drilling bore holes comprising a connecting spigot for connecting to a drill string, said spigot having a longitudinal axis of rotation, a cutting head having a longitudinal axis, eccentric of the spigot axis said cutting head comprising a circumferential face having an axis which is substantially coincident with the cutting head axis and an end face projecting away from said spigot, said end face being substantially conical and coaxial with the axis of rotation of said spigot, said conical end face terminating at a point axially opposite said spigot.
Claim 2
Dependent Claim
93 words
A drill bit for drilling bore holes comprising a connecting spigot for connecting to a drill string, said spigot having a longitudinal axis of rotation, a cutting head having a longitudinal axis, eccentric of the spigot axis said cutting head comprising a circumferential face having an axis which is substantially coincident with the cutting head axis and an end face projecting away from said spigot, said end face being substantially conical and coaxial with the axis of rotation of said spigot, said conical end face terminating at a point axially opposite said spigot.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-01-12 | 1990-07-14 | 1991-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-12 | 1994-07-14 | 1995-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-12 | 1998-07-14 | 1999-01-13 | $7700.00 | Window Closed / Lapsed |