US3539221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of solid materials
Assignee: ROBERT A GLADSTONE
•
Filing: 1967-11-17
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Granted: 1970-11-10
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Expires: 1987-11-17
Abstract
No abstract record available.
Inventors
- 👤 Robert A Gladstone
- 👤 Anthony Kettaneh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:14
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/14; E21B7/15; E21C; E21C37/00; E21C37/18
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-11-09 | 1974-05-11 | 1974-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-09 | 1978-05-11 | 1978-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-09 | 1982-05-11 | 1982-11-10 | $7700.00 | Window Closed / Lapsed |