Patent US2500123A successfully refreshed from Google Patents.
US2500123A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Air filtering apparatus
Assignee: Saco Lowell Shops
•
Filing: 1945-04-27
•
Granted: 1950-03-07
•
Expires: 1965-04-27
Abstract
No abstract record available.
Inventors
- 👤 Eugene C Gwaltney
- 👤 Shaw William
- 👤 Eliot B Maclean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:52
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/24; B01D46/26
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US821819A
Cited
US844842A
Cited
US940076A
Cited
US1444092A
Cited
US1479392A
Cited
US1930890A
Cited
US2009140A
Cited
US2081685A
Cited
US2228129A
Cited
US2315278A
Cited
US2299022A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-03-06 | 1953-09-05 | 1954-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-03-06 | 1957-09-05 | 1958-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-03-06 | 1961-09-05 | 1962-03-07 | $7700.00 | Window Closed / Lapsed |