US4031602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making heat transfer tube
Assignee: Bank of Nova Scotia
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Filing: 1976-09-14
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Granted: 1977-06-28
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Expires: 1996-09-14
Abstract
Abstract Improved heat transfer tube has radial longitudinal fins on a central core and radial transverse fins on its exterior surface. The composite tube is made by the steps of inserting a longitudinally finned core member inside a smooth surfaced outer tube and then subjecting the outer tube to an external finning operation which produces external fins on the tube while reducing the internal tube diameter of the tube sufficiently that the tube will be firmly mechanically bonded to the finned core member.
Inventors
- 👤 James L. Cunningham
- 👤 Bonnie J. Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:00
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/20; B21C37/207; B21C37/151; B21C37/22; B23; B23P; B23P15/00; B23P15/26; F; F28; F28F; F28F1/00; F28F1/10; F28F1/42; F28F1/422; F28F13/00; F28F13/06; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49361; Y10T29/49377; Y10T29/49378; Y10T29/49382; Y10T29/49826; Y10T29/49879
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
82 words
A method of making a heat transfer tube having inner and outer fins comprising the steps of inserting a core member having a plurality of radially extending longitudinal fins inside a smooth surfaced cylindrical tube and subjecting at least a portion of the outside surface of the composite assembly to a plurality of finning tools so as to produce external fins on the tube and reduce its internal diameter to a dimension less than the external diameter of the finned core member.
Claim 2
Independent Claim
82 words
A method of making a heat transfer tube having inner and outer fins comprising the steps of inserting a core member having a plurality of radially extending longitudinal fins inside a smooth surfaced cylindrical tube and subjecting at least a portion of the outside surface of the composite assembly to a plurality of finning tools so as to produce external fins on the tube and reduce its internal diameter to a dimension less than the external diameter of the finned core member.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein said external fins are helically arranged and generally transverse to the axis of the tube.
Claim 4
Dependent Claim
49 words
The method of claim 1 wherein sufficient radial force is applied to the tube during the finning operation to cause the tube wall to tend to become straight, in transverse axial cross-section, in those portions of its circumference which are located between the longitudinal fins on said core member.
Claim 5
Dependent Claim
31 words
The method of claim 3 wherein said radial force is sufficient to cause the tips of said longitudinal fins to become partially embedded in the inner wall surface of said tube.
References Cited (Backward Citations)
US2550965A
Cited
US3753364A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-27 | 1980-12-27 | 1981-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-27 | 1984-12-27 | 1985-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-27 | 1988-12-27 | 1989-06-28 | $7700.00 | Window Closed / Lapsed |