US3683656A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat exchanger apparatus and method of making the same
Assignee: Trane US Inc
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Filing: 1970-03-25
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Granted: 1972-08-15
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Expires: 1990-03-25
Abstract
Abstract A shell-and-tube heat exchanger is shown having a bundle of tubes each of which is provided with external helical fins except in land portions adjacent tube sheets and supports. The tubes are constructed by first rolling grooves into the tube and reducing the tube diameter, then roll extruding fins up from the surface of decreased diameter to a diameter larger than the land portions of the tube and larger than the tube apertures in the tube sheets and supports of the heat exchanger, and finally rolling portions of the fins partially over toward an adjacent fin in a common axial direction to reduce the outer diameter of the fins so that the tube can be passed through the tube apertures of the tube sheets and supports. The rolling over of the fins is accomplished by applying lateral pressure on the fins through the use of a trailing roll-over die. Means is provided for radially withdrawing the groove forming and fin extruding dies from the surface of the tube without an equal withdrawal of the trailing roll-over die whereby all fins exceeding the desired diameter may be bent over to establish the desired fin diameter.
Inventors
- 👤 Carl M Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:39
CPC Classifications
B; B21; B21C; B21C37/00; B21C37/06; B21C37/15; B21C37/20; B21C37/207; B21D; B21D53/00; B21D53/02; B21D53/06; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49377; Y10T29/49378; Y10T29/49382
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
157 words
A method of making a heat exchanger tube adapted to be supported in a tube support aperture of predetermined diameter comprising the steps of: providing a tubular blank having a generally circular cross-section of a predetermined outer diameter which is no greater than said aperture predetermined diameter; forming an extended heat transfer surface by extruding a fully developed helical fin up from the outer surface of said tubular blank to a diameter greater than said predetermined outer diameter and greater than said aperture predetermined diameter; reducing the diameter of said fully developed helical fin to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the extruding step and to a diameter less than said aperture predetermined diameter by applying lateral force to one side of the helix of said helical fin axially of said tubular blank to cause said helical fin to bend over and thereby be reduced in diameter.
Claim 2
Independent Claim
157 words
A method of making a heat exchanger tube adapted to be supported in a tube support aperture of predetermined diameter comprising the steps of: providing a tubular blank having a generally circular cross-section of a predetermined outer diameter which is no greater than said aperture predetermined diameter; forming an extended heat transfer surface by extruding a fully developed helical fin up from the outer surface of said tubular blank to a diameter greater than said predetermined outer diameter and greater than said aperture predetermined diameter; reducing the diameter of said fully developed helical fin to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the extruding step and to a diameter less than said aperture predetermined diameter by applying lateral force to one side of the helix of said helical fin axially of said tubular blank to cause said helical fin to bend over and thereby be reduced in diameter.
Claim 3
Independent Claim
193 words
A method of making a heat exchanger tube adapted to be supported in a tube support aperture of predetermined diameter comprising the steps of: providing a tubular blank of generally circular cross-section of predetermined outer diameter which is no greater than said aperture predetermined diameter; forming an extended heat transfer surface by extruding a fully developed helical fin up from the outer surface of only a portion of said tubular blank to a diameter grEater than said predetermined outer diameter and greater than said aperture predetermined diameter and leaving at least one unfinned land portion; reducing the diameter of the fully developed finned portion to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the extruding step, to less than said aperture predetermined diameter, and to about the diameter of said land portion by bending said helical fin over; and from the step of extruding the helical fin to the step of bending the fin over, maintaining the inner diameter of the span of tubular blank with the extruded bent over fin at substantially the inner diameter of said span existing immediately following the extruding step.
Claim 4
Independent Claim
193 words
A method of making a heat exchanger tube adapted to be supported in a tube support aperture of predetermined diameter comprising the steps of: providing a tubular blank of generally circular cross-section of predetermined outer diameter which is no greater than said aperture predetermined diameter; forming an extended heat transfer surface by extruding a fully developed helical fin up from the outer surface of only a portion of said tubular blank to a diameter grEater than said predetermined outer diameter and greater than said aperture predetermined diameter and leaving at least one unfinned land portion; reducing the diameter of the fully developed finned portion to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the extruding step, to less than said aperture predetermined diameter, and to about the diameter of said land portion by bending said helical fin over; and from the step of extruding the helical fin to the step of bending the fin over, maintaining the inner diameter of the span of tubular blank with the extruded bent over fin at substantially the inner diameter of said span existing immediately following the extruding step.
Claim 5
Independent Claim
227 words
A method of making a heat exchanger tube adapted to be supported in a tube support aperture of predetermined diameter comprising the steps of: providing a tubular blank of generally circular cross-section of predetermined outer diameter which is no greater than said aperture predetermined diameter; forming an extended heat transfer surface by extruding a fully developed helical fin up from the outer surface of only a portion of said tubular blank to a diameter greater than said predetermined outer diameter and greater than said aperture predetermined diameter and leaving at least one unfinned land portion; reducing the diameter of the finned portion to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the extruding step, to less than said aperture predetermined diameter, and to about the diameter of said land portion by applying sufficient lateral force to one side of the helix of said helical fin axially of said tubular blank to cause said helical fin to bend over and thereby be reduced in diameter to about the diameter of said land portion; and from the step of extruding the helical fin to the step of bending the fin over, maintaining the inner diameter of the span of tubular blank with the extruded bent over fin at substantially the inner diameter of said span existing immediately following the extruding step.
Claim 6
Independent Claim
227 words
A method of making a heat exchanger tube adapted to be supported in a tube support aperture of predetermined diameter comprising the steps of: providing a tubular blank of generally circular cross-section of predetermined outer diameter which is no greater than said aperture predetermined diameter; forming an extended heat transfer surface by extruding a fully developed helical fin up from the outer surface of only a portion of said tubular blank to a diameter greater than said predetermined outer diameter and greater than said aperture predetermined diameter and leaving at least one unfinned land portion; reducing the diameter of the finned portion to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the extruding step, to less than said aperture predetermined diameter, and to about the diameter of said land portion by applying sufficient lateral force to one side of the helix of said helical fin axially of said tubular blank to cause said helical fin to bend over and thereby be reduced in diameter to about the diameter of said land portion; and from the step of extruding the helical fin to the step of bending the fin over, maintaining the inner diameter of the span of tubular blank with the extruded bent over fin at substantially the inner diameter of said span existing immediately following the extruding step.
Claim 7
Independent Claim
258 words
A method of providing a tubular blank of a predetermined outer diameter with an extended heat transfer surface in the form of integral helical fins and adapted to be supported in a tube support aperture of predetermined diameter including the steps of: applying radially inward pressure on the outer surfaceof said tubular blank along a helicoidal path to thereby displace the material of said tubular blank causing a general reducing in outer diameter of the tubular blank and a helicoidal groove to be formed in the surface thereof; applying sufficient laterial pressure to the sides of said groove to displace the material between convolutions of said groove radially outward substantially beyond said predetermined diameter thereby forming a fully developed helicoidal fin having a diameter larger than said predetermined outer diameter and greater than said aperture predetermined diameter; and applying sufficient lateral pressure to one side of said groove to cause said helicoidal fin to be bent over sufficiently to reduce the diameter of said fin to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the step of fully developing the helical fin, to less than said aperture predetermined diameter, to about said predetermined outer diameter; and from the step of fully developing the helical fin to the step of bending the fin over, maintaining the inner diameter of the span of tubular blank with the fully developed and bent over fin at substantially the inner diameter of said span existing immediately following the step of fully developing the helical fin.
Claim 8
Independent Claim
258 words
A method of providing a tubular blank of a predetermined outer diameter with an extended heat transfer surface in the form of integral helical fins and adapted to be supported in a tube support aperture of predetermined diameter including the steps of: applying radially inward pressure on the outer surfaceof said tubular blank along a helicoidal path to thereby displace the material of said tubular blank causing a general reducing in outer diameter of the tubular blank and a helicoidal groove to be formed in the surface thereof; applying sufficient laterial pressure to the sides of said groove to displace the material between convolutions of said groove radially outward substantially beyond said predetermined diameter thereby forming a fully developed helicoidal fin having a diameter larger than said predetermined outer diameter and greater than said aperture predetermined diameter; and applying sufficient lateral pressure to one side of said groove to cause said helicoidal fin to be bent over sufficiently to reduce the diameter of said fin to a diameter less than the outer diameter of said fully developed helical fin existing immediately following the step of fully developing the helical fin, to less than said aperture predetermined diameter, to about said predetermined outer diameter; and from the step of fully developing the helical fin to the step of bending the fin over, maintaining the inner diameter of the span of tubular blank with the fully developed and bent over fin at substantially the inner diameter of said span existing immediately following the step of fully developing the helical fin.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |