US2500931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drilling apparatus
Assignee: Joy Manufacturing Co
•
Filing: 1944-11-15
•
Granted: 1950-03-21
•
Expires: 1964-11-15
Abstract
No abstract record available.
Inventors
- 👤 John C Curtis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 15:19
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/02; E21B7/025; E21B7/022
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-03-20 | 1953-09-19 | 1954-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-03-20 | 1957-09-19 | 1958-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-03-20 | 1961-09-19 | 1962-03-21 | $7700.00 | Window Closed / Lapsed |