Patent US1764660A successfully refreshed from Google Patents.
US1764660A
Expired / Lapsed
US
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Filter and method of forming the same
Assignee: Individual
•
Filing: 1927-10-31
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Granted: 1930-06-17
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Expires: 1947-10-31
Abstract
No abstract record available.
Inventors
- 👤 Ernest J Sweetland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:39
CPC Classifications
B; B01; B01D; B01D36/00; B01D36/003; B01D27/00; B01D27/005; B01D27/02; B01D27/04; B01D27/06
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1933-06-16 | 1933-12-16 | 1934-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1937-06-16 | 1937-12-16 | 1938-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1941-06-16 | 1941-12-16 | 1942-06-17 | $7700.00 | Window Closed / Lapsed |