US3485372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for biological purification of waste water,primarily sewage,and removal of nutritive salts from the purified waste water
Assignee: Individual
•
Filing: 1968-05-17
•
Granted: 1969-12-23
•
Expires: 1988-05-17
Abstract
No abstract record available.
Inventors
- 👤 Carl Sigvard Nordgard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 22:30
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/08; C02F3/082; Y; Y02; Y02W; Y02W10/00; Y02W10/10
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1972-12-22 | 1973-06-23 | 1973-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-12-22 | 1977-06-23 | 1977-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-12-22 | 1981-06-23 | 1981-12-23 | $7700.00 | Window Closed / Lapsed |