US1990251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchange apparatus
Assignee: Westinghouse Electric Corp
•
Filing: 1933-04-17
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Granted: 1935-02-05
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Expires: 1953-04-17
Abstract
No abstract record available.
Inventors
- 👤 John A Potter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:07
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/16; F28D7/163; F28D7/1638; F28D7/1646; F28F; F28F9/00; F28F9/02; F28F9/0236; F28F9/0241; Y; Y10; Y10S; Y10S165/00; Y10S165/051; Y10S165/052; Y10S165/053; Y10S165/054
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) | 1938-02-04 | 1938-08-06 | 1939-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-02-04 | 1942-08-06 | 1943-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-02-04 | 1946-08-06 | 1947-02-05 | $7700.00 | Window Closed / Lapsed |