US3820215A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making a curved spined heat exchanger tube
Assignee: Peerless of America Inc
•
Filing: 1973-04-27
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Granted: 1974-06-28
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Expires: 1993-04-27
Abstract
Abstract THE METHOD OF MAKING A CURVED, SPINED HEAT TRANSFER ELEMENT BY APPLYING BENDING FORCES ONLY TO PORTIONS DISPOSED OUTWARDLY OF THE SPINES.
Inventors
- 👤 S Pasternak
- 👤 S Pasternak Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:33
CPC Classifications
B; B21; B21D; B21D7/00; B21D7/08; B21J; B21J5/00; B21J5/06; B21J5/068; B23; B23P; B23P15/00; B23P15/26; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-27 | 1977-12-27 | 1978-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-27 | 1981-12-27 | 1982-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-27 | 1985-12-27 | 1986-06-28 | $7700.00 | Window Closed / Lapsed |