US3498372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchangers
Assignee: National Research Development Corp UK
•
Filing: 1968-04-10
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Granted: 1970-03-03
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Expires: 1988-04-10
Abstract
No abstract record available.
Inventors
- 👤 Thomas Diery Patten
- 👤 John Leslie Collins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:06
CPC Classifications
F; F28; F28D; F28D9/00; F28D9/0031; F28D9/0037; F28D9/0062; F28F; F28F3/00; F28F3/02; F28F3/04; Y; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/356; Y10S165/393; Y10S165/394
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-03-02 | 1973-09-01 | 1974-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-03-02 | 1977-09-01 | 1978-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-03-02 | 1981-09-01 | 1982-03-03 | $7700.00 | Window Closed / Lapsed |