Patent US1650140A successfully refreshed from Google Patents.
US1650140A
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US
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Heat-interchange device
Assignee: Airco Inc
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Filing: 1922-11-13
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Granted: 1927-11-22
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Expires: 1942-11-13
Abstract
No abstract record available.
Inventors
- 👤 Kuhni Hans
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:39
CPC Classifications
F; F28; F28F; F28F25/00; F28F25/02; F28F25/08; F28F25/087
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) | 1930-11-21 | 1931-05-23 | 1931-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1934-11-21 | 1935-05-23 | 1935-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1938-11-21 | 1939-05-23 | 1939-11-22 | $7700.00 | Window Closed / Lapsed |