US4157155A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sealing apparatus and method
Assignee: Individual
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Filing: 1978-05-15
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Granted: 1979-06-05
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Expires: 1998-05-15
Abstract
Abstract A set of metal heat exchange tubes is simultaneously brazed into a metal tube sheet more rapidly and with greater uniformity by holding tube-and-sheet assembly under radiant heater with sheet essentially horizontal and carrying brazing metal, and forcing gases from above tubes down into tubes as assembly is heated. Heater can have heating surface enveloping the top and sides of the sheet, or can have flat heating surface, but is preferably a ceramic fiber gas burner. Burner can be divided into two portions using a single ceramic fiber mat and separate combustion mixture supplies, with non-combustible gas fed through one portion when other portion is the only one operating.
Inventors
- 👤 Thomas M. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:29
CPC Classifications
B; B23; B23K; B23K1/00; B23K1/005; F; F23; F23D; F23D14/00; F23D14/12; F23D14/16; F28; F28F; F28F9/00; F28F9/02; F28F9/04; F28F9/16; F28F9/18; F23D2203/00; F23D2203/10; F23D2203/101; F23D2203/1012; F23D2900/00; F23D2900/14; F23D2900/14001
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
160 words
An apparatus for simultaneously sealing a plurality of metal heat exchange tubes in a metal tube sheet having openings through which one end of each tube projects, said apparatus having support means for holding an assembly of tubes in a sheet with the sheet in essentially horizontal position and carrying on its upper surface a quantity of fusible metallic sealant adequate to seal all the tube ends in the sheet, radiant heating means mounted immediately over the tube-and-sheet assembly as supported by the support means, and oriented to heat essentially only the top of the assembly, to bring the sheet of that assembly to a temperature at least as high as the fusion point of the fusible metallic sealant, and gas moving means connected to at least one of the other means to propel gases from above the tube ends down through the tube ends as the assembly is heated, to effect more uniform heating and sealing of the tubes.
Claim 2
Independent Claim
160 words
An apparatus for simultaneously sealing a plurality of metal heat exchange tubes in a metal tube sheet having openings through which one end of each tube projects, said apparatus having support means for holding an assembly of tubes in a sheet with the sheet in essentially horizontal position and carrying on its upper surface a quantity of fusible metallic sealant adequate to seal all the tube ends in the sheet, radiant heating means mounted immediately over the tube-and-sheet assembly as supported by the support means, and oriented to heat essentially only the top of the assembly, to bring the sheet of that assembly to a temperature at least as high as the fusion point of the fusible metallic sealant, and gas moving means connected to at least one of the other means to propel gases from above the tube ends down through the tube ends as the assembly is heated, to effect more uniform heating and sealing of the tubes.
Claim 3
Dependent Claim
20 words
The combination of claim 1 in which the radiant heating means envelopes essentially only the top of the tube-and-sheet assembly.
Claim 4
Dependent Claim
16 words
The combination of claim 1 in which the radiant heating means is a ceramic fiber burner.
Claim 5
Dependent Claim
128 words
A process for simultaneously brazing a plurality of metal heat exchange tubes in a metal tube sheet, which process comprises, holding an assembly of such tubes each having one end in a sheet with the sheet in essentially horizontal position and carrying on its upper surface a quantity or brazing metal adequate to seal all tubes into the sheet, applying radiant heat downwardly on the sheet to heat essentially only the top of the assembly to bring the sheet at least to the fusion point of the brazing metal, and moving gases from above the tube ends down through the tube ends during the heating to cause the heating to be more uniformly applied to the tubes so that the sealant rapidly seals all tubes to the sheet.
Claim 6
Dependent Claim
128 words
A process for simultaneously brazing a plurality of metal heat exchange tubes in a metal tube sheet, which process comprises, holding an assembly of such tubes each having one end in a sheet with the sheet in essentially horizontal position and carrying on its upper surface a quantity or brazing metal adequate to seal all tubes into the sheet, applying radiant heat downwardly on the sheet to heat essentially only the top of the assembly to bring the sheet at least to the fusion point of the brazing metal, and moving gases from above the tube ends down through the tube ends during the heating to cause the heating to be more uniformly applied to the tubes so that the sealant rapidly seals all tubes to the sheet.
Claim 7
Dependent Claim
25 words
The combination of claim 4 in which radiant heat is applied from a radiant heater that envelopes essentially only the top of the tube-and-sheet assembly.
Claim 8
Dependent Claim
17 words
The combination of claim 4 in which the radiant heat is applied from a ceramic fiber burner.
Claim 9
Dependent Claim
27 words
The combination of claim 4 in which the heating to at least the fusion point of the braze is effected in not over about half a minute.
Claim 10
Dependent Claim
32 words
The combination of claim 1 in which the radiant heating means has a heat output that brings the sheet to the sealant fusing temperature in no more than about half a minute.
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) | 1982-06-04 | 1982-12-04 | 1983-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-04 | 1986-12-04 | 1987-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-04 | 1990-12-04 | 1991-06-05 | $7700.00 | Window Closed / Lapsed |