Patent US3406747A successfully refreshed from Google Patents.
US3406747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchanger having concentric supply and exhaust conduits
Assignee: AMERICAN SCHACK CO Inc
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Filing: 1966-01-18
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Granted: 1968-10-22
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Expires: 1986-01-18
Abstract
No abstract record available.
Inventors
- 👤 Alan J White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 18:51
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/005; F28D7/06; F28F; F28F2265/00; F28F2265/26; Y; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/40; Y10S165/401; Y10S165/405
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) | 1971-10-22 | 1972-04-22 | 1972-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-10-22 | 1976-04-22 | 1976-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-10-22 | 1980-04-22 | 1980-10-22 | $7700.00 | Window Closed / Lapsed |