Patent US1666873A successfully refreshed from Google Patents.
US1666873A
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Duplex pumping apparatus
Assignee: Chicago Pump Co
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Filing: 1927-04-27
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Granted: 1928-04-17
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Expires: 1947-04-27
Abstract
No abstract record available.
Inventors
- 👤 Jr Augustus C Durdin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:50
CPC Classifications
F; F04; F04D; F04D15/00; F04D15/02; F04D15/029
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) | 1931-04-17 | 1931-10-17 | 1932-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1935-04-17 | 1935-10-17 | 1936-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1939-04-17 | 1939-10-17 | 1940-04-17 | $7700.00 | Window Closed / Lapsed |