Patent US2744727A successfully refreshed from Google Patents.
US2744727A
Expired / Lapsed
US
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Drill pipe float valve
Assignee: Individual
•
Filing: 1951-10-18
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Granted: 1956-05-08
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Expires: 1971-10-18
Abstract
No abstract record available.
Inventors
- 👤 Henry G Osburn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:16
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/10; Y; Y10; Y10T; Y10T137/00; Y10T137/7504; Y10T137/7722; Y10T137/7837; Y10T137/7904; Y10T137/7922; Y10T137/7929; Y10T137/7932; Y10T137/7933
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1790480A
Cited
US1615811A
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US1811885A
Cited
US1984107A
Cited
US2092822A
Cited
US2100615A
Cited
US2192670A
Cited
US2471382A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-05-08 | 1959-11-07 | 1960-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-05-08 | 1963-11-07 | 1964-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-05-08 | 1967-11-07 | 1968-05-08 | $7700.00 | Window Closed / Lapsed |