US3843862A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave oven having tm and te modes
Assignee: General Electric Co
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Filing: 1974-01-04
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Granted: 1974-10-22
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Expires: 1994-01-04
Abstract
Abstract A counter-top microwave oven comprises an upstanding box-like metal wall structure defining a heating cavity, a microwave generator, transmission means including a probe antenna for radiating the microwaves into the heating cavity from the top thereof, and tuning means disposed in the heating cavity adjacent to the top thereof, the cavity being so dimensioned and the antenna and tuning means being so positioned as to excite in the cavity a predetermined low impedance transverse magnetic field mode and a predetermined high impedance transverse electric field mode having a low impedance region in the portion of the heating cavity in which food is normally placed. Two alternative positions of the tuning means for establishing the preferred field patterns are disclosed.
Inventors
- 👤 J Staats
- 👤 L Fitzmayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:50
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/70; H05B6/705; H05B6/6426; Y; Y02; Y02B; Y02B40/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
199 words
Electronic heating apparatus for heating a low impedance body, said apparatus comprising a metal enclosure in the form of a rectangular parallelepiped including a top wall, a bottom wall, a front wall, a rear wall and two opposed side walls defining a heating cavity for receiving therein a body to be heated, source means including a probe antenna electrically coupled to said heating cavity along said top wall for transmitting microwave energy of a predetermined wavelength lambda into said heating cavity to excite therein two predetermined electromagnetic field modes, said heating cavity having an electrical width substantially equal to 1.2 lambda and an electrical height substantially equal to 0.633 lambda and an electrical depth substantially equal to 1.1 lambda , and tuning means disposed in said heating cavity adjacent to the top thereof, one of said predetermined electromagnetic field modes being a relatively low impedance transverse magnetic field mode, the other of said predetermined electromagnetic field modes being a relatively high impedance transverse electric field mode having a relatively low impedance region generally centrally of said heating cavity, whereby there is established in said heating cavity an electromagnetic field pattern providing uniform heating of an associated low impedance body.
Claim 2
Dependent Claim
199 words
Electronic heating apparatus for heating a low impedance body, said apparatus comprising a metal enclosure in the form of a rectangular parallelepiped including a top wall, a bottom wall, a front wall, a rear wall and two opposed side walls defining a heating cavity for receiving therein a body to be heated, source means including a probe antenna electrically coupled to said heating cavity along said top wall for transmitting microwave energy of a predetermined wavelength lambda into said heating cavity to excite therein two predetermined electromagnetic field modes, said heating cavity having an electrical width substantially equal to 1.2 lambda and an electrical height substantially equal to 0.633 lambda and an electrical depth substantially equal to 1.1 lambda , and tuning means disposed in said heating cavity adjacent to the top thereof, one of said predetermined electromagnetic field modes being a relatively low impedance transverse magnetic field mode, the other of said predetermined electromagnetic field modes being a relatively high impedance transverse electric field mode having a relatively low impedance region generally centrally of said heating cavity, whereby there is established in said heating cavity an electromagnetic field pattern providing uniform heating of an associated low impedance body.
Claim 3
Dependent Claim
37 words
The electronic heating apparatus set forth in claim 1, wherein said antenna is disposed substantially midway between said side walls and is spaced from said rear wall an electrical distance one-fourth the depth of said heating cavity.
Claim 4
Dependent Claim
47 words
The electronic heating apparatus set forth in claim 1, wherein said antenna is disposed substantially mdiway between said side walls and is spaced from said rear wall an electrical distance one-fourth the depth of said heating cavity, said tuning means being disposed centrally of said top wall.
Claim 5
Dependent Claim
66 words
The electronic heating apparatus set forth in claim 1, wherein said antenna is disposed substantially midway between said side walls and is spaced from said rear wall an electrical distance one-fourth the depth of said heating cavity, said tuning means being disposed substantially midway between said side walls and being spaced from said front wall an electrical distance one-fourth of the depth of said heating cavity.
Claim 6
Dependent Claim
17 words
The electronic heating apparatus set forth in claim 1, wherein lambda is approximately equal to 12.9 inches.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |