US1440778A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water indicator for oil wells
Assignee: Individual
•
Filing: 1921-05-21
•
Granted: 1923-01-02
•
Expires: 1941-05-21
Abstract
No abstract record available.
Inventors
- 👤 Walter L Foster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 20:18
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1926-01-01 | 1926-07-03 | 1927-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1930-01-01 | 1930-07-03 | 1931-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1934-01-01 | 1934-07-03 | 1935-01-02 | $7700.00 | Window Closed / Lapsed |