Patent US2657576A successfully refreshed from Google Patents.
US2657576A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Perforation production tester
Assignee: Individual
•
Filing: 1947-03-03
•
Granted: 1953-11-03
•
Expires: 1967-03-03
Abstract
No abstract record available.
Inventors
- 👤 Jr Robert O Boykin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:47
CPC Classifications
E; E21; E21B; E21B49/00; E21B49/08; E21B49/10
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1200722A
Cited
US1606104A
Cited
US1893162A
Cited
US1889889A
Cited
US2143962A
Cited
US2158569A
Cited
US2187047A
Cited
US2262655A
Cited
US2313369A
Cited
US2441894A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-11-02 | 1957-05-04 | 1957-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-11-02 | 1961-05-04 | 1961-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-11-02 | 1965-05-04 | 1965-11-03 | $7700.00 | Window Closed / Lapsed |