US4140887A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for microwave heating
Assignee: ALLEGHENY INTERNATIONAL ACCEPTANCE Corp
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Filing: 1977-05-09
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Granted: 1979-02-20
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Expires: 1997-05-09
Abstract
Abstract An object responsive to microwave energy is enclosed in a thermally insulated enclosure which is substantially transparent to microwave energy and is heated by microwave energy passing through the enclosure. The apparatus includes a chamber which supports the magnetron radiators and has thermal insulated walls and an insulated base on which the object rests.
Inventors
- 👤 Willard H. Sutton
- 👤 Walter E. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:31
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; C; C04; C04B; C04B33/00; C04B33/32; C04B35/00; C04B35/622; C04B35/64
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
94 words
A method of heating a formed cast member of alumina, calcium aluminate cement and water responsive to microwave energy to a temperature above 800° F. which comprises initially heating the object relatively slowly to a temperature between qpproximately 400 and 800° F. by transmitting microwave energy directly thereto until substantially all water is removed therefrom, and then heating the object relatively rapidly by transmitting increased microwave energy directly thereto while the object is enclosed in an enclosure transparent to microwave energy and having thermal insulating properties with the heat being confined within said enclosure.
Claim 2
Independent Claim
94 words
A method of heating a formed cast member of alumina, calcium aluminate cement and water responsive to microwave energy to a temperature above 800° F. which comprises initially heating the object relatively slowly to a temperature between qpproximately 400 and 800° F. by transmitting microwave energy directly thereto until substantially all water is removed therefrom, and then heating the object relatively rapidly by transmitting increased microwave energy directly thereto while the object is enclosed in an enclosure transparent to microwave energy and having thermal insulating properties with the heat being confined within said enclosure.
Claim 3
Dependent Claim
38 words
The method of claim 1 in which at least part of the initial heating is obtained by transmitting microwave energy thereto while the object is enclosed in an enclosure transparent to microwave energy and having thermal insulting properties.
Claim 4
Independent Claim
74 words
A method of heating an object having water therein responsive to microwave energy to a temperature above 800° F. which comprises initially heating the object relatively slowly to a temperature between approximately 400 and 800° F. by transmitting microwave energy directly thereto until substantially all water is removed therefrom, said microwave energy being applied during said initial heating step at a concentration of 75 to 100 watts radiated power per pound of the object.
Claim 5
Independent Claim
74 words
A method of heating an object having water therein responsive to microwave energy to a temperature above 800° F. which comprises initially heating the object relatively slowly to a temperature between approximately 400 and 800° F. by transmitting microwave energy directly thereto until substantially all water is removed therefrom, said microwave energy being applied during said initial heating step at a concentration of 75 to 100 watts radiated power per pound of the object.
Claim 6
Dependent Claim
44 words
The method of claim 3, in which the microwave energy is applied during said second heating step at a concentration as high as possible but not in excess of 300 watts per pound of the dry object until the final desired temperature is reached.
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) | 1982-02-19 | 1982-08-21 | 1983-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-02-19 | 1986-08-21 | 1987-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-02-19 | 1990-08-21 | 1991-02-20 | $7700.00 | Window Closed / Lapsed |