Patent US2870784A successfully refreshed from Google Patents.
US2870784A
Expired / Lapsed
US
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Drilling string float valve
Assignee: Individual
•
Filing: 1955-01-19
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Granted: 1959-01-27
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Expires: 1975-01-19
Abstract
No abstract record available.
Inventors
- 👤 Walls Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:59
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/10; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7854; Y10T137/7857; Y10T137/7904; Y10T137/7922; Y10T137/7929; Y10T137/7932; Y10T137/7933
Claims Analysis
Total Claims: 0
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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) | 1962-01-26 | 1962-07-28 | 1963-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-01-26 | 1966-07-28 | 1967-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-01-26 | 1970-07-28 | 1971-01-27 | $7700.00 | Window Closed / Lapsed |