US3604104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing aluminum brazed coil
Assignee: Individual
•
Filing: 1969-02-26
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Granted: 1971-09-14
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Expires: 1989-02-26
Abstract
Abstract A method of producing an all-aluminum coil is disclosed. In accordance with the method disclosed, hairpin coil tubes and coil fins are assembled with headers, return bends and inlet and outlet tubes. The ends of the hairpin tubes are expanded to receive the return tube portions with a predetermined clearance and the tubes are loaded with a solder ring at the expanded ends thereof. The fins are provided with solder-clad spacing collars around openings therethrough through which the hairpin tubes extend. The hairpin tubes are then expanded to mechanically secure the fin collars to the hairpin tubes. The assembled coil is then placed in a preheat oven and preheated to approximately 1,000* F. to bring the solder to a buttery consistency, after which the preheated coil assembly is immersed in molten Barium chloride salt at approximately 1,100* F. so that the solder rings and cladding on the collars braze the tubes and fins together. The brazed coil assembly is then washed in a hot ammonia bath. Sodium fluoride and lithium chloride fluxes are added to the salt bath to prevent oxidation of the coil components and to control the melting point of the salt bath, respectively.
Inventors
- 👤 Paul H Glasgow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:09
CPC Classifications
F; F28; F28D; F28D7/00; F28D7/08; F28D7/082; F28D7/085; B; B21; B21D; B21D53/00; B21D53/02; B21D53/08; B23; B23K; B23K1/00; B23K1/0008; B23K1/0012; F28F; F28F21/00; F28F21/08; F28F21/081; F28F21/084
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
92 words
A method of producing an aluminum coil comprising aSsembling coil components with aluminum alloy solder, preheating the assembled coil to approximately 1,000* F. to bring the solder to a buttery state, dipping the preheated assembled coil in a molten salt bath comprising as its major component barium chloride and also including sodium fluoride and lithium chloride flux maintained at approximately 1,100* F. to braze the coil components together, and removing the brazed coil from the salt bath and immersing the coil in an ammonia bath to neutralize the effects of fluxes thereon.
Claim 2
Independent Claim
92 words
A method of producing an aluminum coil comprising aSsembling coil components with aluminum alloy solder, preheating the assembled coil to approximately 1,000* F. to bring the solder to a buttery state, dipping the preheated assembled coil in a molten salt bath comprising as its major component barium chloride and also including sodium fluoride and lithium chloride flux maintained at approximately 1,100* F. to braze the coil components together, and removing the brazed coil from the salt bath and immersing the coil in an ammonia bath to neutralize the effects of fluxes thereon.
Claim 3
Dependent Claim
37 words
The method as set forth in claim 1, wherein the solder includes 13 percent to 15 percent silicon, 0.25 percent copper, 0.70 percent iron, 0.25 percent zinc, 0.10 percent magnesium, 0.15 percent manganese and the balance aluminum.
Claim 4
Dependent Claim
25 words
The method as set forth in claim 1, wherein the ammonium bath is a 5 percent ammonia bath and is maintained at approximately 200* F.
Claim 5
Independent Claim
247 words
A method of producing an aluminum coil structure having headers with openings therethrough, hairpin tubes, fins having openings therethrough with aluminum alloy solder-clad collars therearound, return bend tubes, inlet and outlet tubes, and aluminum alloy solder rings, said solder including approximately 13 percent to 15 percent silicon, 0.25 percent copper, 0.70 percent iron, 0.25 percent zinc, 0.10 percent magnesium, 0.15 percent manganese and the balance aluminum, comprising assembling said coil components by inserting the hairpin tubes through the openings in the headers and through the openings in the fins, expanding the hairpin tubes at the ends thereof to mechanically secure said tubes to the headers and fins, loading each end of the return bend tubes with aluminum alloy solder rings and inserting said return tubes with the solder therearound into the expanded ends of the hairpin tubes so as to have the rings fitting snugly over the ends of the return bend tubes and over the expanded open ends of the hairpin tubes thus connecting the two tubes together, preheating the assembled coil to approximately 1,000* F. to bring the solder to a buttery state, dipping the preheated assembled coil in a molten salt bath comprising as its major component barium chloride and also including sodium fluoride and lithium chloride flux maintained at approximately 1,100* F. to braze the coil components together, and removing the brazed coil from the salt bath and immersing the coil in an ammonia bath to neutralize the effects of the fluxes thereon.
Claim 6
Independent Claim
247 words
A method of producing an aluminum coil structure having headers with openings therethrough, hairpin tubes, fins having openings therethrough with aluminum alloy solder-clad collars therearound, return bend tubes, inlet and outlet tubes, and aluminum alloy solder rings, said solder including approximately 13 percent to 15 percent silicon, 0.25 percent copper, 0.70 percent iron, 0.25 percent zinc, 0.10 percent magnesium, 0.15 percent manganese and the balance aluminum, comprising assembling said coil components by inserting the hairpin tubes through the openings in the headers and through the openings in the fins, expanding the hairpin tubes at the ends thereof to mechanically secure said tubes to the headers and fins, loading each end of the return bend tubes with aluminum alloy solder rings and inserting said return tubes with the solder therearound into the expanded ends of the hairpin tubes so as to have the rings fitting snugly over the ends of the return bend tubes and over the expanded open ends of the hairpin tubes thus connecting the two tubes together, preheating the assembled coil to approximately 1,000* F. to bring the solder to a buttery state, dipping the preheated assembled coil in a molten salt bath comprising as its major component barium chloride and also including sodium fluoride and lithium chloride flux maintained at approximately 1,100* F. to braze the coil components together, and removing the brazed coil from the salt bath and immersing the coil in an ammonia bath to neutralize the effects of the fluxes thereon.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |