Patent US3490752A successfully refreshed from Google Patents.
US3490752A
Expired / Lapsed
US
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Aeration device for sewage plants with biological purification
Assignee: Individual
•
Filing: 1967-01-31
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Granted: 1970-01-20
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Expires: 1987-01-31
Abstract
No abstract record available.
Inventors
- 👤 Martin Danjes
- 👤 August Schreiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:18
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/20; B; B01; B01F; B01F23/00; B01F23/20; B01F23/23; B01F23/231; B01F23/23105; B01F23/2312; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y10; Y10S; Y10S261/00; Y10S261/70
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1319646A
Cited
CA597951A
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US1642051A
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US1717713A
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US1743926A
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US2049333A
Cited
US2978234A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-01-19 | 1973-07-21 | 1974-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-01-19 | 1977-07-21 | 1978-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-01-19 | 1981-07-21 | 1982-01-20 | $7700.00 | Window Closed / Lapsed |