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Patent US3531404A successfully refreshed from Google Patents.
US3531404A
Expired / Lapsed
US
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Sewage treatment system
Assignee: Smith and Loveless Inc
•
Filing: 1968-04-01
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Granted: 1970-09-29
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Expires: 1988-04-01
Abstract
No abstract record available.
Inventors
- 👤 Brian L Goodman
- 👤 Robert M Appleberry
- 👤 John W Struewing
- 👤 Frank G Weis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:18
CPC Classifications
C; C02; C02F; C02F11/00; C02F11/12; C02F11/121; C02F11/123; B; B01; B01D; B01D33/00; B01D33/04; B01D33/44; B01D33/46; B01D33/463
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB222221A
Cited
US2021122A
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US1958279A
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US2097529A
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US2798609A
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US2848113A
Cited
US3053392A
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US3200949A
Cited
US3117927A
Cited
US3259570A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-09-28 | 1974-03-30 | 1974-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-09-28 | 1978-03-30 | 1978-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-09-28 | 1982-03-30 | 1982-09-29 | $7700.00 | Window Closed / Lapsed |