Patent US1981282A successfully refreshed from Google Patents.
Patent US1839126A successfully refreshed from Google Patents.
US1839126A
Expired / Lapsed
US
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Impeller
Assignee: American Well Works
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Filing: 1929-05-17
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Granted: 1931-12-29
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Expires: 1949-05-17
Abstract
No abstract record available.
Inventors
- 👤 John B Sperry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:41
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/18; F04D29/181; F04D29/183; F04D29/22; F04D29/2238; F04D29/225
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) | 1934-12-28 | 1935-06-29 | 1935-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-12-28 | 1939-06-29 | 1939-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-12-28 | 1943-06-29 | 1943-12-29 | $7700.00 | Window Closed / Lapsed |