Patent US3750709A successfully refreshed from Google Patents.
US3750709A
Expired / Lapsed
US
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Heat-exchange tubing and method of making it
Assignee: Wolverine Tube Canada Inc
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Filing: 1972-02-29
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Granted: 1973-08-07
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Expires: 1992-02-29
Abstract
Abstract Heat-exchange tubing with a peripheral wall of oblong crosssection, and inner fins on the wall of which the fins on either of two opposite flat wall sections extend with their tips at least to the level of the tips of the fins on the other flat wall section, and a method of forming the tubing from a round innerfin tube blank, involving partially flattening the round blank into the tubing with its peripheral wall of oblong crosssection.
Inventors
- 👤 F French
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:47
CPC Classifications
G; G11; G11C; G11C7/00; G11C7/10; G11C7/1048; B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/20; B21C37/202; B21C37/207; F; F28; F28D; F28D7/00; F28D7/02; F28D7/024; F28F; F28F1/00; F28F1/02; F28F1/022; F28F1/025; F28F1/10; F28F1/40; F28F1/42; F28F1/422; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378; Y10T29/49384
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
130 words
Longitudinal heat-exchange tubing, having a longitudinal axis and a peripheral metal wall of oblong cross-section, with the wall providing two opposite spaced flat wall sections parallel to each other and two opposite return wall sections joining said flat wall sections, and spaced metal fins integral with and projecting inwardly from said wall with said fins having tips and being of equal height, the fins on each of said flat wall sections extending inclined to said axis and parallel to each other, the fins on said flat wall sections being inclined to and crossing each other, and the fins on Either of said flat wall sections extending with their tips beyond the level of the tips of the fins on the other flat wall section but being spaced from the latter.
Claim 2
Dependent Claim
130 words
Longitudinal heat-exchange tubing, having a longitudinal axis and a peripheral metal wall of oblong cross-section, with the wall providing two opposite spaced flat wall sections parallel to each other and two opposite return wall sections joining said flat wall sections, and spaced metal fins integral with and projecting inwardly from said wall with said fins having tips and being of equal height, the fins on each of said flat wall sections extending inclined to said axis and parallel to each other, the fins on said flat wall sections being inclined to and crossing each other, and the fins on Either of said flat wall sections extending with their tips beyond the level of the tips of the fins on the other flat wall section but being spaced from the latter.
Claim 3
Dependent Claim
26 words
Longitudinal heat-exchange tubing as in claim 1, in which the tips of the fins on said flat wall sections are at their crossings notched and interlocked.
References Cited (Backward Citations)
GB332280A
Cited
US2149696A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-06 | 1977-02-05 | 1977-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-06 | 1981-02-05 | 1981-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-06 | 1985-02-05 | 1985-08-07 | $7700.00 | Window Closed / Lapsed |