US3472619A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of phosphoric acid and calcium sulfate
Assignee: Singmaster and Breyer
•
Filing: 1968-02-26
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Granted: 1969-10-14
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Expires: 1988-02-26
Abstract
No abstract record available.
Inventors
- 👤 Roman Chelminski
- 👤 Robert L Somerville
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 23:36
CPC Classifications
C; C01; C01B; C01B25/00; C01B25/16; C01B25/18; C01B25/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-13 | 1973-04-14 | 1973-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-13 | 1977-04-14 | 1977-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-13 | 1981-04-14 | 1981-10-14 | $7700.00 | Window Closed / Lapsed |