US3704158A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of powdered chalk
Assignee: Individual
•
Filing: 1970-12-03
•
Granted: 1972-11-28
•
Expires: 1990-12-03
Abstract
Abstract POWDERED CHALK HAVING A SURFACE WHICH IS NON-REACTIVE WITH ACIDS.
Inventors
- 👤 George Alexander Rohan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:38
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/18; C01F11/185; C09; C09C; C09C1/00; C09C1/02; C09C1/021; C09C1/022; C09C1/024; C09C3/00; C09C3/006; C09C3/06; C09C3/063; C09C3/08; C09C3/10; D; D21; D21H; D21H17/00; D21H17/63; D21H17/67; D21H17/69; C01P; C01P2004/00; C01P2004/80
Claims Analysis
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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) | 1975-11-28 | 1976-05-29 | 1976-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-28 | 1980-05-29 | 1980-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-28 | 1984-05-29 | 1984-11-28 | $7700.00 | Window Closed / Lapsed |