Patent US3404674A successfully refreshed from Google Patents.
US3404674A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchange apparatus for the employment of flue gas heat
Assignee: KRIS G ALBERT
•
Filing: 1967-07-25
•
Granted: 1968-10-08
•
Expires: 1987-07-25
Abstract
No abstract record available.
Inventors
- 👤 Kris G Albert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:46
CPC Classifications
F; F24; F24H; F24H6/00; F24D; F24D5/00; F24H1/00; F24H1/18; F24H1/20; F24H1/205; F24D2200/00; F24D2200/16; F24D2200/18
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1971-10-08 | 1972-04-08 | 1972-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-10-08 | 1976-04-08 | 1976-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-10-08 | 1980-04-08 | 1980-10-08 | $7700.00 | Window Closed / Lapsed |