Patent US3404446A successfully refreshed from Google Patents.
US3404446A
Expired / Lapsed
US
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Method of securing fins in a heat exchanger
Assignee: Peerless of America Inc
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Filing: 1965-10-24
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Granted: 1968-10-08
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Expires: 1985-10-24
Abstract
No abstract record available.
Inventors
- 👤 Richard W Kritzer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:08
CPC Classifications
B; B21; B21D; B21D53/00; B21D53/02; B21D53/08; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/22; B21C37/225; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49826; Y10T29/49908; Y10T29/49915
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US754195A
Cited
US851978A
Cited
US2342117A
Cited
US2375068A
Cited
US2395878A
Cited
US2713997A
Cited
US2772861A
Cited
US3100930A
Cited
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 |