US3746824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave oven leakage radiation detecting device
Assignee: General Electric Co
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Filing: 1972-08-07
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Granted: 1973-07-17
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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 gasket. The device, located within the door frame of the oven, includes two metallic sensor probes coupled in parallel and extending in a resonant channel-like space formed by the inner surface of the door and the door frame external to the door seal gasket. The sensor probes are arranged so as to communicate with the electric field of the microwave energy and are longitudinally spaced within the channel by odd multiples of one-quarter wavelength of the excitation microwave frequency of the oven. The sensor probes are operatively coupled to voltage amplifier circuitry, the output of which is coupled to a responder. In the presence of radiation above a predetermined level escaping from the oven cavity, a voltage will be sensed by at least one of the probes and will be amplified by the amplifier circuitry so as to activate the responder, a neon lamp, providing a visible indication of the presence of the leakage radiation in excess of a predetermined level.
Inventors
- 👤 R Prucha
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:51
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/6432
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
144 words
A microwave oven having a metallic box-like oven liner and a metallic access door defining an oven cooking cavity, a door frame surrounding the oven liner adjacent the access door, means for supplying microwave energy to the oven cavity, microwave radiation seal means between the door and the oven liner to prevent the escape of radiation, a continuous, resonant, channellike space external to the radiation seal means, and leakage radiation detecting means with a plurality of electricallyconductive sensor probes projecting into the resonant channellike space so as to communicate with the electric field of the microwave energy and longitudinally spaced by odd multiples of one-quarter wavelength at the operating microwave frequency of the oven, signal processor means coupled with the sensor probes, and responder means coupled with the output of the signal processor means for providing an indication of the presence of leakage radiation.
Claim 2
Dependent Claim
144 words
A microwave oven having a metallic box-like oven liner and a metallic access door defining an oven cooking cavity, a door frame surrounding the oven liner adjacent the access door, means for supplying microwave energy to the oven cavity, microwave radiation seal means between the door and the oven liner to prevent the escape of radiation, a continuous, resonant, channellike space external to the radiation seal means, and leakage radiation detecting means with a plurality of electricallyconductive sensor probes projecting into the resonant channellike space so as to communicate with the electric field of the microwave energy and longitudinally spaced by odd multiples of one-quarter wavelength at the operating microwave frequency of the oven, signal processor means coupled with the sensor probes, and responder means coupled with the output of the signal processor means for providing an indication of the presence of leakage radiation.
Claim 3
Dependent Claim
208 words
A microwave oven having a metallic box-like oven liner and a metallic access door hingedly attached to the oven at the bottom thereof forming an oven cooking cavity, a front door frame surrounding the oven liner adjacent the front door opening, means for supplying microwave energy to the oven cavity, a metallic radiation seal gasket attached to the inner surface of the door around the periphery thereof and positioned to contact the liner flange around the entire opening when the door is closed for preventing the escape of radiation from the cavity, a continuous resonant channel defined by the inner surface of the door and the front door frame external to the gasket, and a leakage radiation detecting device with two metallic sensor probes coupled in parallel and projecting into the resonant channel so as to communicate with the electric field of the microwave energy and longitudinally spaced by odd multiples of one-quarter wavelength at the operating microwave frequency of the oven, signal processor means operatively coupled with the sensor probes and including means for adjusting the output thereof for calibration purposes, and responder means coupled with the output of the signal processor means for providing an indication of the presence of leakage radiation above a predetermined level.
Claim 4
Dependent Claim
208 words
A microwave oven having a metallic box-like oven liner and a metallic access door hingedly attached to the oven at the bottom thereof forming an oven cooking cavity, a front door frame surrounding the oven liner adjacent the front door opening, means for supplying microwave energy to the oven cavity, a metallic radiation seal gasket attached to the inner surface of the door around the periphery thereof and positioned to contact the liner flange around the entire opening when the door is closed for preventing the escape of radiation from the cavity, a continuous resonant channel defined by the inner surface of the door and the front door frame external to the gasket, and a leakage radiation detecting device with two metallic sensor probes coupled in parallel and projecting into the resonant channel so as to communicate with the electric field of the microwave energy and longitudinally spaced by odd multiples of one-quarter wavelength at the operating microwave frequency of the oven, signal processor means operatively coupled with the sensor probes and including means for adjusting the output thereof for calibration purposes, and responder means coupled with the output of the signal processor means for providing an indication of the presence of leakage radiation above a predetermined level.
Claim 5
Dependent Claim
20 words
The device of claim 2 wherein the sensor probes project into the channel in the uppermost section of the oven.
Claim 6
Dependent Claim
13 words
The device of claim 2 wherein the responder means is a neon lamp.
References Cited (Backward Citations)
US3679908A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |