Patent US3749875A successfully refreshed from Google Patents.
US3749875A
Expired / Lapsed
US
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Microwave oven leakage detection system
Assignee: General Electric Co
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Filing: 1972-08-07
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Granted: 1973-07-31
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Expires: 1992-08-07
Abstract
Abstract An electronic microwave oven has incorporated therewithin a leakage radiation detecting device for sensing and providing an indication of the presence of radiation escaping from the oven cavity past the door seal. The device, located centrally within a collection cavity waveguide formed within the hollow oven door, includes an antenna probe projecting into the collection cavity waveguide coupled with the appropriate amplification circuitry and a neon lamp. Elongated coupling slots are provided on each side of the door located in the channel-like area external to the door seal, each slot having a length of approximately one-half the wavelength of the operating frequency of the microwave oven. Any microwave radiation escaping past the door seal is coupled through the slots into the radiation collection cavity within the door and is sensed by the antenna probe. The amplification circuitry is set to cause the neon lamp to be activated when the radiation at the antenna probe reaches a predetermined level.
Inventors
- 👤 L Fitzmayer
- 👤 N Worden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 21:03
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/6432
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
73 words
A microwave oven radiation leakage monitor comprising: an hollow oven access door having microwave sealing means between the door and the body of the oven; means for coupling at least a portion of any microwave radiation escaping past the door seal into the interior of the access door; and means responsive to said coupled microwave energy within the door for providing an indication of excess microwave radiation leakage past the oven door seal.
Claim 2
Dependent Claim
73 words
A microwave oven radiation leakage monitor comprising: an hollow oven access door having microwave sealing means between the door and the body of the oven; means for coupling at least a portion of any microwave radiation escaping past the door seal into the interior of the access door; and means responsive to said coupled microwave energy within the door for providing an indication of excess microwave radiation leakage past the oven door seal.
Claim 3
Dependent Claim
27 words
The monitor of claim 1 in which said energy responsive means includes an antenna probe projecting into the interior of said door at approximately the center thereof.
Claim 4
Dependent Claim
28 words
The monitor of claim 1 in which said coupling means comprises a plurality of elongated slots in the door surface adjacent the exterior side of the door seal.
Claim 5
Dependent Claim
18 words
The monitor of claim 3 in which the elongated slots are on opposing sides of the door surface.
Claim 6
Dependent Claim
144 words
In a microwave oven of the type having a metallic box-like oven liner and a hollow metallic access door defining an oven cooking cavity, and microwave radiation sealing means between the door and oven liner, a leakage radiation detecting monitor comprising: a leakage-radiation collection-cavity waveguide formed within the hollow access door; at least one elongated coupling slot located on each side of the hollow access door external to the radiation sealing means and opening into the collection cavity waveguide, each slot having a length approximately equal to whole multiples of one-half wavelength of the operating microwave frequency; antenna probe means projecting into the collection cavity waveguide for sensing microwave radiation appearing therein; and means coupled to the antenna probe and responsive to energy sensed by the probe for providing an indication of microwave radiation leakage past the door seal that exceeds a predetermined level.
Claim 7
Dependent Claim
144 words
In a microwave oven of the type having a metallic box-like oven liner and a hollow metallic access door defining an oven cooking cavity, and microwave radiation sealing means between the door and oven liner, a leakage radiation detecting monitor comprising: a leakage-radiation collection-cavity waveguide formed within the hollow access door; at least one elongated coupling slot located on each side of the hollow access door external to the radiation sealing means and opening into the collection cavity waveguide, each slot having a length approximately equal to whole multiples of one-half wavelength of the operating microwave frequency; antenna probe means projecting into the collection cavity waveguide for sensing microwave radiation appearing therein; and means coupled to the antenna probe and responsive to energy sensed by the probe for providing an indication of microwave radiation leakage past the door seal that exceeds a predetermined level.
Claim 8
Dependent Claim
20 words
The monitor of claim 5 wherein the probe means projects into the collection cavity waveguide at approximately the center thereof.
Claim 9
Dependent Claim
39 words
The monitor of claim 5 wherein three such elongated coupling slots are located respectively on the top and bottom sides of the door and one such slot is located respectively on each of the remaining sides of the door.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |