US2718435A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mud feeder for oil wells
Assignee: Individual
•
Filing: 1952-07-22
•
Granted: 1955-09-20
•
Expires: 1972-07-22
Abstract
No abstract record available.
Inventors
- 👤 Hubert W Hudspeth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:10
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/06; E21B21/062
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) | 1958-09-19 | 1959-03-21 | 1959-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-09-19 | 1963-03-21 | 1963-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-09-19 | 1967-03-21 | 1967-09-20 | $7700.00 | Window Closed / Lapsed |