Patent US2149696A successfully refreshed from Google Patents.
US2149696A
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Method of making heat exchangers
Assignee: Metropolitan Engineering Co
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Filing: 1936-03-13
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Granted: 1939-03-07
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Expires: 1956-03-13
Abstract
No abstract record available.
Inventors
- 👤 Henry S Holmes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:50
CPC Classifications
B; B21; B21D; B21D53/00; B21D53/02; F; F24; F24H; F24H1/00; F24H1/18; F24H1/20; F24H1/205; F24H1/206; F24H9/00; F24H9/0005; F24H9/001; F24H9/0026; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378; Y10T29/49384
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) | 1942-03-06 | 1942-09-05 | 1943-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-03-06 | 1946-09-05 | 1947-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-03-06 | 1950-09-05 | 1951-03-07 | $7700.00 | Window Closed / Lapsed |