Patent US2831659A successfully refreshed from Google Patents.
US2831659A
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US
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Earth coring apparatus
Assignee: Shell Development Co
•
Filing: 1954-05-13
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Granted: 1958-04-22
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Expires: 1974-05-13
Abstract
No abstract record available.
Inventors
- 👤 Kukuchek George Stephen
- 👤 Hersey Edwin Spalding
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:27
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/02; E21B7/027; E21B7/028; E21B10/00; E21B10/44; E21B17/00; E21B17/02; E21B17/04; E21B17/046; E21B17/0465; E21B49/00; E21B49/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US1420242A
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US1577605A
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US1785405A
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US2334312A
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US2315590A
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DE804314C
Cited
US2643858A
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US2562841A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-04-21 | 1961-10-21 | 1962-04-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-04-21 | 1965-10-21 | 1966-04-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-04-21 | 1969-10-21 | 1970-04-22 | $7700.00 | Window Closed / Lapsed |