US2638372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digging tool
Assignee: Individual
•
Filing: 1947-09-29
•
Granted: 1953-05-12
•
Expires: 1967-09-29
Abstract
No abstract record available.
Inventors
- 👤 Walter R Proetz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 09:30
CPC Classifications
E; E21; E21B; E21B11/00; E21B11/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US208749A
Cited
US281193A
Cited
US333452A
Cited
US576756A
Cited
US2028680A
Cited
US652077A
Cited
US1187316A
Cited
US1888929A
Cited
US2230498A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-11 | 1956-11-10 | 1957-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-11 | 1960-11-10 | 1961-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-11 | 1964-11-10 | 1965-05-12 | $7700.00 | Window Closed / Lapsed |