US2839318A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stuffing box for oil wells with blow-out preventer
Assignee: Individual
•
Filing: 1957-03-25
•
Granted: 1958-06-17
•
Expires: 1977-03-25
Abstract
No abstract record available.
Inventors
- 👤 Frank F Ackermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:32
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/02; E21B33/03; E21B33/06
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US121985A
Cited
FR14059E
Cited
US923908A
Cited
GB190814120A
Cited
US1549842A
Cited
US1539236A
Cited
US1782696A
Cited
US1879478A
Cited
US1930982A
Cited
US1845683A
Cited
US2245007A
Cited
US2363688A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-06-16 | 1961-12-16 | 1962-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-06-16 | 1965-12-16 | 1966-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-06-16 | 1969-12-16 | 1970-06-17 | $7700.00 | Window Closed / Lapsed |