EP0457470A1
Expired / Lapsed
EP
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Tube for heat exchangers and a method for manufacturing the tube
Assignee: Altemira Co Ltd
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Filing: 1991-05-03
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Granted: —
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Expires: 2011-05-03
Abstract
Abstract A tube for heat exchangers is a flat tube which either comprises a pair of plane walls which are spaced a predetermined distance from one another, the plane walls respectively having one lateral ends integrally connected to each other by a U-shaped bent portion, the plane walls further having their other lateral ends which abut against to be tightly secured to one another, or alternatively, the flat tube comprises as the plane walls a pair of preformed plates having the abutted and soldered portions at both lateral ends. The tube further comprising one or more curved lugs integral with and protruding inwardly from an inner surface of each plane wall, and the curved lugs respectively having innermost tops so that the innermost tops protruding from one plane wall bear against the inner surface of the other plane wall or against the innermost tops of the other curved lugs protruding from said other plane wall. The tube is thus of an improved pressure resistance despite its minimized height or thickness, and the manufacturing process of the tube involves no difficulty to produce the tubes at a high productivity and lower manufacturing cost.
Inventors
- 👤 Wataru Ouchi
- 👤 Katsuhisa Suzuki
- 👤 Toshinori Tokutake
- 👤 Hirosaburo Hirano
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-05 16:49
CPC Classifications
F; F28; F28F; F28F3/00; F28F3/02; F28F3/04; F28F3/042; F28F3/044; F28D; F28D1/00; F28D1/02; F28D1/03; F28D1/0308; F28D1/0316; F28D1/0391; F28D21/00; F28D2021/0019; F28D2021/008; F28D2021/0084; F28F1/00; F28F1/02; F28F2001/027; F28F2275/00; F28F2275/12; F28F2275/122; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/4935; Y10T29/49373; Y10T29/49377; Y10T29/49378; Y10T29/49391
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
129 words
A tube for heat exchangers, the tube comprising: a pair of plane walls spaced a predetermined distance from one another; the plane walls respectively having one lateral ends integrally connected to each other by a U-shaped bent portion; the plane walls further having their other lateral ends which abut against and are tightly secured to one another to define a flat configuration of the tube; one or more curved lugs integral with and protruding inwardly from an inner surface of each plane wall; and the curved lugs respectively having innermost tops, wherein the innermost tops protruding from one plane wall bear against and integral with the inner surface of the other plane wall or with the innermost tops of the other curved lugs protruding from said other plane wall.
Claim 2
Dependent Claim
45 words
A tube according to claim 1, wherein the curved lugs are such tightly folded gathers as extending along the tube, and alternately protrude from one and the other plane walls so as to divide an internal space thereof into a plurality of separate coolant paths.
Claim 3
Dependent Claim
40 words
A tube according to claim 1, wherein the curved lugs are such dimpled recesses as formed integral with the plane walls, and are distributed over the inner surfaces thereof so as to form a stray coolant path within the tube.
Claim 4
Dependent Claim
30 words
A tube according to claim 1, wherein the other lateral ends of the plane walls comprise creased edges which are abutted in parallel with and soldered integral with each other.
Claim 5
Dependent Claim
110 words
A tube for heat exchangers, the tube comprising: a pair of preformed plates spaced a predetermined distance from one another, with the preformed plates being tightly secured to one another at both lateral ends to define a flat configuration of the tube; one or more curved lugs integral with and protruding inwardly from an inner surface of each preformed plate; and the curved lugs respectively having innermost tops, wherein the innermost tops of the curved lugs protruding from one preformed plate bear against and integral with the inner surface of the other preformed plate or with the innermost tops of the other curved lugs protruding from said other preformed plate.
Claim 6
Dependent Claim
34 words
A tube according to claim 5, wherein both lateral ends of the preformed plates are folded down to form L-shaped bent portions which are abutted in parallel with and soldered integral with each other.
Claim 7
Independent Claim
158 words
A method for manufacturing a tube for heat exchangers, the method comprising the steps of: preparing a strip of a predetermined width; forming one or more curved lugs protruding from and integral with inner surfaces of both lateral sides of a middle portion of the strip; bending the strip, having the curved lugs, at the middle portion into a U-shape in cross section so as to form plane walls corresponding to the lateral sides; thereafter abutting lateral extremities of the plane walls one on another; welding the lateral extremities one to another to form an ellipse in cross section such that innermost tops of the curved lugs of one plane wall do engage with the inner surface of the other plane wall or with opposite innermost tops of the other curved lugs of said other plane wall; and then soldering the innermost tops to the inner surface or to the opposite innermost tops with which they are engaging.
Claim 8
Dependent Claim
52 words
The method according to claim 7, wherein the curved lugs are formed by tightly folding lateral extremities into gathers which extend along the tube and alternate in transverse direction thereof from one and the other plane walls so as to divide an internal space thereof into a plurality of separate coolant paths.
Claim 9
Dependent Claim
43 words
The method according to claim 7, wherein the curved lugs are formed by recessing portions of the plane walls into dimples which are integral therewith and distributed over the inner surfaces of the plane walls so as to form a stray coolant path.
Claim 10
Independent Claim
166 words
A method for manufacturing a tube for heat exchangers, the method comprising the steps of: preparing a strip of a predetermined width; forming one or more curved lugs protruding from and integral with inner surfaces of both lateral sides of a middle portion of the strip; bending the strip, having the curved lugs, at the middle portion into a U-shape in cross section so as to form plane walls corresponding to the lateral sides; thereafter abutting lateral extremities of the plane walls one on another so as to form an ellipse in cross section such that inner most tops of the curved lugs of one plane wall engage with the inner surface of the other plane wall or with opposite innermost tops of the other curved lugs of said other plane wall; and then soldering in one-shot operation the lateral extremities abutting one on another as well as the innermost tops to the inner surface or to the opposite innermost tops with which they are engaging.
Claim 11
Dependent Claim
52 words
The method according to claim 10, wherein the curved lugs are formed by tightly folding lateral extremities into gathers which extend along the tube and alternate in transverse direction thereof from one and the other plane walls so as to divide an internal space thereof into a plurality of separate coolant paths.
Claim 12
Dependent Claim
43 words
The method according to claim 10, wherein the curved lugs are formed by recessing portions of the plane walls into dimples which are integral therewith and distributed over the inner surfaces of the plane walls so as to form a stray coolant path.
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FR2156359A1
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EP0283937A1
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GB2223091A
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