Patent US3611534A successfully refreshed from Google Patents.
US3611534A
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US
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Method of making expanded integral fin sheet metal tubing for use in heat exchangers
Assignee: Olin Corp
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Filing: 1969-09-25
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Granted: 1971-10-12
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Expires: 1989-09-25
Abstract
Abstract A SHEET METAL TUBING HAVING INTEGRALLY FORMED WEB SECTIONS WHICH ARE SLIT TO FORM FINS. THE FIN SURFACE AREA IS INCREASED BY CORRUGATING THE WEB SECTIONS PRIOR TO SLITTING THEM INTO FINS. AFTER SLITTING, THE FINS ARE FLATTENED OR SHAPED AS DESIRED, AND THEN TWISTED OR BENT TO FORM THE DESIRED ARRAY. THE SHEET METAL TUBING MAY BE FORMED INTO A VARIETY OF SHAPES SUCH AS COILS FOR USE IN HEAT EXCHANGERS IN APPLICATIONS SUCH AS REFRIGERATORS.
Inventors
- 👤 Norval A Keith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:28
CPC Classifications
F; F28; F28F; F28F1/00; F28F1/10; F28F1/12; F28F1/14; F28F1/16; B; B21; B21D; B21D31/00; B21D31/04; B21D53/00; B21D53/02; B21D53/04; B21D53/045; F28F3/00; F28F3/02; F28F3/025; F28F3/027; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49366; Y10T29/49369; Y10T29/49371
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-10-11 | 1975-04-12 | 1975-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-10-11 | 1979-04-12 | 1979-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-10-11 | 1983-04-12 | 1983-10-12 | $7700.00 | Window Closed / Lapsed |