US3626154A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transparent furnace
Assignee: Massachusetts Institute of Technology
•
Filing: 1970-02-05
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Granted: 1971-12-07
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Expires: 1990-02-05
Abstract
Abstract A furnace which heats by infrared radiation includes a wall portion of material transparent to visible radiation having a layer of selected material on the inside thereof, which reflects substantially all infrared radiation and yet transmits sufficient visible radiation so that the inside of the furnace can be viewed from the outside.
Inventors
- 👤 Thomas B Reed
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:28
CPC Classifications
F; F27; F27D; F27D11/00; F27D11/02; H; H05; H05B; H05B3/00; H05B3/62; H05B3/64
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
125 words
A furnace for heating a body by infrared radiation comprising, a first transparent cylinder containing the body, a second transparent cylinder concentric with and enclosing the first cylinder and defining an annular space therebetween, a layer of material on the inside of the second cylinder, the plasma wavelength of the material being less than the wavelength of the infrared radiation, an electrically energized infrared radiator in the annular space, the radiating surfaces thereof being distributed throughout the annular space, the thickness of the layer of material being such that it substantially reflects infrared and transmits visible radiation, whereby the body is heated and is visible through the transparent cylinders between said radiating surfaces and thermal insulating means closing the ends of said first transparent cylinder.
Claim 2
Dependent Claim
125 words
A furnace for heating a body by infrared radiation comprising, a first transparent cylinder containing the body, a second transparent cylinder concentric with and enclosing the first cylinder and defining an annular space therebetween, a layer of material on the inside of the second cylinder, the plasma wavelength of the material being less than the wavelength of the infrared radiation, an electrically energized infrared radiator in the annular space, the radiating surfaces thereof being distributed throughout the annular space, the thickness of the layer of material being such that it substantially reflects infrared and transmits visible radiation, whereby the body is heated and is visible through the transparent cylinders between said radiating surfaces and thermal insulating means closing the ends of said first transparent cylinder.
Claim 3
Dependent Claim
26 words
In a furnace or oven as in claim 1 and in which, the material is substantially inert to gases and vapors in the furnace or oven.
Claim 4
Dependent Claim
17 words
In a furnace or oven as in claim 1 and in which, the material is a metal.
Claim 5
Dependent Claim
20 words
In a furnace or oven as in claim 1 and in which, the material is a relatively heavily doped semiconductor.
Claim 6
Dependent Claim
16 words
In a furnace or oven as in claim 1 and in which, the metal is gold.
Claim 7
Dependent Claim
25 words
In a furnace as in claim 5 and in which, the thickness of the gold layer is dependent on the operating temperature of the furnace.
Claim 8
Dependent Claim
22 words
In a furnace as in claim 5 and in which, the thickness of the gold layer is less than 1,000 angstrom units.
Claim 9
Dependent Claim
30 words
In a furnace as in claim 5 and in which, the gold layer is between 100 and 1,000 angstrom units thick and the infrared radiation temperature is about 1,000* C.
Claim 10
Dependent Claim
16 words
In a furnace or oven as in claim 1 and in which, the metal is silver.
Claim 11
Dependent Claim
17 words
In a furnace or oven as in claim 1, and in which, the semiconductor is indium oxide.
Claim 12
Dependent Claim
20 words
In a furnace or oven as in claim 1 and in which, the semiconductor is indium oxide doped with tin.
Claim 13
Dependent Claim
19 words
A furnace as in claim 1 and in which, the source of infrared radiation is an electrically heated radiator.
Claim 14
Dependent Claim
17 words
A furnace as in claim 1 and in which, means are provided for cooling the second cylinder.
Claim 15
Dependent Claim
25 words
A furnace as in claim 13 and in which, the material is gold, the first mentioned transparent cylinder is quartz and the second is Pyrex.
Claim 16
Dependent Claim
24 words
A furnace as in claim 14 and further including, a transparent jacket enclosing the second cylinder and a transparent fluid coolant in the jacket.
References Cited (Backward Citations)
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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) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |