US2679936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for filtering
Assignee: Commonwealth Engineering Company of Ohio
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Filing: 1951-05-04
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Granted: 1954-06-01
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Expires: 1971-05-04
Abstract
No abstract record available.
Inventors
- 👤 David E Bench
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:14
CPC Classifications
B; B01; B01D; B01D33/00; B01D33/44; B01D33/46; B01D33/466; B01D33/06; B01D33/073; B01D37/00; B01D37/02; B01D37/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1579171A
Cited
US2055869A
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US2270938A
Cited
US2321455A
Cited
US2576288A
Cited
US2576275A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-05-31 | 1957-11-30 | 1958-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-31 | 1961-11-30 | 1962-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-31 | 1965-11-30 | 1966-06-01 | $7700.00 | Window Closed / Lapsed |