Patent US1730293A successfully refreshed from Google Patents.
US1730293A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat interchanger
Assignee: Individual
•
Filing: 1927-08-01
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Granted: 1929-10-01
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Expires: 1947-08-01
Abstract
No abstract record available.
Inventors
- 👤 Forrest C Reed
- 👤 Frank A Ernst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:17
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/02; F28D7/024
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) | 1932-09-30 | 1933-04-01 | 1933-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1936-09-30 | 1937-04-01 | 1937-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1940-09-30 | 1941-04-01 | 1941-10-01 | $7700.00 | Window Closed / Lapsed |