US2421907A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Well pressure gauge
Assignee: California Research LLC
•
Filing: 1944-12-26
•
Granted: 1947-06-10
•
Expires: 1964-12-26
Abstract
No abstract record available.
Inventors
- 👤 William R Postlewaite
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 01:38
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/06
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1266570A
Cited
US2059549A
Cited
US2292549A
Cited
US2327935A
Cited
US2365015A
Cited
US2295528A
Cited
US2318724A
Cited
US2357353A
Cited
US2336500A
Cited
US2360886A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-06-09 | 1950-12-09 | 1951-06-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-06-09 | 1954-12-09 | 1955-06-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-06-09 | 1958-12-09 | 1959-06-10 | $7700.00 | Window Closed / Lapsed |