US2920872A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water separator for air drilling
Assignee: Hughes Tool Co
•
Filing: 1957-12-23
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Granted: 1960-01-12
•
Expires: 1977-12-23
Abstract
No abstract record available.
Inventors
- 👤 George W Baur
- 👤 Henry B Woods
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:27
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/002; E21B21/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-11 | 1963-07-13 | 1964-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-11 | 1967-07-13 | 1968-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-11 | 1971-07-13 | 1972-01-12 | $7700.00 | Window Closed / Lapsed |