US2400853A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Well drilling apparatus
Assignee: Individual
•
Filing: 1941-07-08
•
Granted: 1946-05-21
•
Expires: 1961-07-08
Abstract
No abstract record available.
Inventors
- 👤 Walter P Stilley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:41
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/06; E21B4/10; E21B10/00; E21B10/36; Y; Y10; Y10S; Y10S415/00; Y10S415/903
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) | 1949-05-20 | 1949-11-19 | 1950-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1953-05-20 | 1953-11-19 | 1954-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1957-05-20 | 1957-11-19 | 1958-05-21 | $7700.00 | Window Closed / Lapsed |