Patent US2151540A successfully refreshed from Google Patents.
US2151540A
Expired / Lapsed
US
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Heat exchanger and method of making same
Assignee: Individual
•
Filing: 1936-06-12
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Granted: 1939-03-21
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Expires: 1956-06-12
Abstract
No abstract record available.
Inventors
- 👤 Varga Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:48
CPC Classifications
F; F28; F28F; F28F3/00; F28F3/02; 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) | 1942-03-20 | 1942-09-19 | 1943-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-03-20 | 1946-09-19 | 1947-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-03-20 | 1950-09-19 | 1951-03-21 | $7700.00 | Window Closed / Lapsed |