US3530990A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sewage treatment system
Assignee: Environmental Services Inc
•
Filing: 1969-05-08
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Granted: 1970-09-29
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Expires: 1989-05-08
Abstract
No abstract record available.
Inventors
- 👤 Derald E Grimshaw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:27
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/1236; C02F3/1242; C02F3/006; C02F3/26; Y; Y02; Y02W; Y02W10/00; Y02W10/10
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) | 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 |