Patent US2444774A successfully refreshed from Google Patents.
US2444774A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Purification of raw waters
Assignee: PQ Corp
•
Filing: 1943-11-03
•
Granted: 1948-07-06
•
Expires: 1963-11-03
Abstract
No abstract record available.
Inventors
- 👤 Harold R Hay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:19
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1687919A
Cited
US1997114A
Cited
US1943487A
Cited
US1989380A
Cited
GB451826A
Cited
US2234285A
Cited
US2217466A
Cited
GB499247A
Cited
US2267831A
Cited
US2310009A
Cited
US2241641A
Cited
US2307466A
Cited
US2310655A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-07-06 | 1952-01-05 | 1952-07-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-07-06 | 1956-01-05 | 1956-07-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-07-06 | 1960-01-05 | 1960-07-06 | $7700.00 | Window Closed / Lapsed |