US3522727A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measuring apparatus for drilling rigs
Assignee: Tenneco Oil Co
•
Filing: 1968-12-27
•
Granted: 1970-08-04
•
Expires: 1988-12-27
Abstract
No abstract record available.
Inventors
- 👤 Charles W Calhoun
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:12
CPC Classifications
E; E21; E21B; E21B45/00
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2330753A
Cited
US3374669A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-08-03 | 1974-02-02 | 1974-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-08-03 | 1978-02-02 | 1978-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-08-03 | 1982-02-02 | 1982-08-04 | $7700.00 | Window Closed / Lapsed |