US2767020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Distributor for trickling filters
Assignee: Dorr Oliver Inc
•
Filing: 1953-12-21
•
Granted: 1956-10-16
•
Expires: 1973-12-21
Abstract
No abstract record available.
Inventors
- 👤 Knowles John Herbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:56
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/04; C02F3/043; Y; Y02; Y02W; Y02W10/00; Y02W10/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2225836A
Cited
US2347330A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-10-16 | 1960-04-16 | 1960-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-10-16 | 1964-04-16 | 1964-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-10-16 | 1968-04-16 | 1968-10-16 | $7700.00 | Window Closed / Lapsed |