Patent US2988915A successfully refreshed from Google Patents.
US2988915A
Expired / Lapsed
US
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Apparatus for measuring weight on well drilling bit
Assignee: Core Laboratories Inc
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Filing: 1957-08-22
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Granted: 1961-06-20
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Expires: 1977-08-22
Abstract
No abstract record available.
Inventors
- 👤 Robert F Knight
- 👤 Ralph E Jenkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:13
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/007
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2365014A
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US2528883A
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US2703008A
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US2743340A
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US2749754A
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US2851880A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-06-19 | 1964-12-19 | 1965-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-06-19 | 1968-12-19 | 1969-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-06-19 | 1972-12-19 | 1973-06-20 | $7700.00 | Window Closed / Lapsed |