Patent US1134934A successfully refreshed from Google Patents.
Patent US3812851A successfully refreshed from Google Patents.
Patent US2421423A successfully refreshed from Google Patents.
US2421423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for taking physical measurements in boreholes
Assignee: GEOPHYSICAL DEV CORP
•
Filing: 1943-02-15
•
Granted: 1947-06-03
•
Expires: 1963-02-15
Abstract
No abstract record available.
Inventors
- 👤 Krasnow Shelley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:44
CPC Classifications
E; E21; E21B; E21B47/00; E21B47/06; G; G01; G01V; G01V9/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1950-06-02 | 1950-12-02 | 1951-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-06-02 | 1954-12-02 | 1955-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-06-02 | 1958-12-02 | 1959-06-03 | $7700.00 | Window Closed / Lapsed |