Patent US2784557A successfully refreshed from Google Patents.
US2784557A
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US
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Engine compound for drilling rigs
Assignee: Oil States Industries Inc
•
Filing: 1951-04-17
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Granted: 1957-03-12
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Expires: 1971-04-17
Abstract
No abstract record available.
Inventors
- 👤 Wilson John Hart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 13:00
CPC Classifications
E; E21; E21B; E21B3/00; E21B3/02; E21B3/04; E21B3/06; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19014
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1125172A
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US1858911A
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US2171994A
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US2204877A
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US2344681A
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US2536483A
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US2509039A
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US2613059A
Cited
US2589121A
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US2639630A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-03-11 | 1960-09-10 | 1961-03-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-03-11 | 1964-09-10 | 1965-03-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-03-11 | 1968-09-10 | 1969-03-12 | $7700.00 | Window Closed / Lapsed |