Patent US3604783A successfully refreshed from Google Patents.
US3604783A
Expired / Lapsed
US
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Microwave cavity viewers
Assignee: DCA Food Industries Inc
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Filing: 1969-06-30
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Granted: 1971-09-14
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Expires: 1989-06-30
Abstract
Abstract Viewing ports for microwave ovens. In a first embodiment, a transparent mirror is placed over a relatively large aperture in the wall of the oven with the metallic coating of the mirror bearing against the metallic wall of the oven. The interior of the oven is illuminated. The metallic coating of the mirror prevents microwave energy from being transmitted through the mirror, while the one-way viewing characteristic of the mirror allows visible light to be transmitted through it. In a second embodiment, a waveguide is connected between the aperture in the oven and a viewing port. Two prisms are provided, one at the oven aperture and the other at the viewing port. Visible light from inside the oven is reflected by the aperture prism down the waveguide and by the viewing port prism out of the viewing port. Any microwave energy which is transmitted down the waveguide is attanuated both as a result of the waveguide dimensions and special attenuators provided for this purpose. The prism mounted at the oven aperture can be rotated so that the interior of the oven can be scanned.
Inventors
- 👤 Howard Roth
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:32
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/647; H05B6/6482; H05B6/76; H05B6/766
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
166 words
In combination with means including a plurality of walls forming a microwave cavity, a viewing arrangement for said cavity comprising means for illuminating said cavity, an elongated tunnel mounted on one of said walls of said cavity and having one end opening into said cavity for allowing said tunnel to communicate with said cavity, first light reflecting means mounted in said tunnel adjacent said one end for reflecting visible light from the interior of said cavity along said tunnel, a tunnel opening providing a viewing port in said tunnel spaced from said one end and facing away from said cavity, second light reflecting means mounted in said tunnel adjacent said viewing port for reflecting light transmitted along said tunnel from said first light reflecting means through said viewing port, said tunnel having a width small enough and a length between said two light reflecting means long enough such that microwave energy transmitted from said one opening to said viewing porT is attenuated to a safe level.
Claim 2
Dependent Claim
166 words
In combination with means including a plurality of walls forming a microwave cavity, a viewing arrangement for said cavity comprising means for illuminating said cavity, an elongated tunnel mounted on one of said walls of said cavity and having one end opening into said cavity for allowing said tunnel to communicate with said cavity, first light reflecting means mounted in said tunnel adjacent said one end for reflecting visible light from the interior of said cavity along said tunnel, a tunnel opening providing a viewing port in said tunnel spaced from said one end and facing away from said cavity, second light reflecting means mounted in said tunnel adjacent said viewing port for reflecting light transmitted along said tunnel from said first light reflecting means through said viewing port, said tunnel having a width small enough and a length between said two light reflecting means long enough such that microwave energy transmitted from said one opening to said viewing porT is attenuated to a safe level.
Claim 3
Dependent Claim
147 words
In combination with means including a plurality of walls forming a microwave cavity, a viewing arrangement for said cavity comprising means for illuminating said cavity, an elongated tunnel mounted on one of said walls of said cavity and having one end opening into said cavity, first light reflecting means mounted in said tunnel adjacent said one end for reflecting visible light from the the interior of said cavity along the tunnel, a tunnel opening providing a viewing port in said tunnel spaced from said one end and facing away from said cavity, second light reflecting means mounted in said tunnel adjacent said viewing port for reflecting light transmitted along said tunnel from said first light reflecting means through said viewing port and means for attenuating microwave energy transmitted along said tunnel such that the microwave energy which exists at said viewing port is at a safe level.
Claim 4
Dependent Claim
147 words
In combination with means including a plurality of walls forming a microwave cavity, a viewing arrangement for said cavity comprising means for illuminating said cavity, an elongated tunnel mounted on one of said walls of said cavity and having one end opening into said cavity, first light reflecting means mounted in said tunnel adjacent said one end for reflecting visible light from the the interior of said cavity along the tunnel, a tunnel opening providing a viewing port in said tunnel spaced from said one end and facing away from said cavity, second light reflecting means mounted in said tunnel adjacent said viewing port for reflecting light transmitted along said tunnel from said first light reflecting means through said viewing port and means for attenuating microwave energy transmitted along said tunnel such that the microwave energy which exists at said viewing port is at a safe level.
Claim 5
Dependent Claim
30 words
An arrangement for viewing the interior of a microwave cavity in accordance with claim 2 wherein said microwave energy attenuating means includes a plurality of posts mounted along said tunnel.
Claim 6
Dependent Claim
27 words
An arrangement for viewing the interior of a microwave cavity in accordance with claim 2 further including means in said tunnel for absorbing microwave energy transmitted therealong.
Claim 7
Dependent Claim
25 words
An arrangement for viewing the interior of a microwave cavity in accordance with claim 2 wherein said first and second light reflecting means are prisms.
Claim 8
Dependent Claim
38 words
An arrangement for viewing the interior of a microwave cavity in accordance with claim 5 wherein the first prism is mounted for rotatable movement within said tunnel such that the interior of said microwave cavity can be scanned.
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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) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |