US2970812A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drum type heat exchanger
Assignee: Individual
•
Filing: 1956-06-14
•
Granted: 1961-02-07
•
Expires: 1976-06-14
Abstract
No abstract record available.
Inventors
- 👤 Richard W Kritzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:28
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/04; Y; Y10; Y10S; Y10S165/00; Y10S165/355; Y10S165/40; Y10S165/401; Y10S165/416
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1822068A
Cited
US1849396A
Cited
US2035665A
Cited
US2213463A
Cited
US2164854A
Cited
US2657018A
Cited
US2716802A
Cited
US2820617A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-02-07 | 1964-08-08 | 1965-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-02-07 | 1968-08-08 | 1969-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-02-07 | 1972-08-08 | 1973-02-07 | $7700.00 | Window Closed / Lapsed |