Patent US3665140A successfully refreshed from Google Patents.
US3665140A
Expired / Lapsed
US
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Microwave chamber having energy density control system
Assignee: Varian Medical Systems Inc
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Filing: 1970-02-09
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Granted: 1972-05-23
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Expires: 1990-02-09
Abstract
Abstract A microwave treating chamber is disclosed which includes a monitor for determining the average energy density of the microwave field within the chamber and a feedback control system which responds to the monitor by maintaining the energy density within the chamber constant. The monitor includes a duct which extends a substantial distance through the chamber and through which water is passed at a constant rate. Thermistors in the duct on opposite sides of the chamber measure the total thermal energy imparted to the water by the radiation within the chamber. This total energy gain provides a precise indication of the average energy density along the path of the duct of the microwave field. An electrical feedback loop from the monitor is included for controlling the intensity of the radiation fed to the chamber in order to maintain the energy density constant.
Inventors
- 👤 Jerome R White
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:03
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/80; H05B6/802; H05B6/6447; H05B6/645; H05B6/78; H05B6/782
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
196 words
Electromagnetic radiation treating apparatus comprising a treating chamber capable of confining an electromagnetic radiation field, means foR supporting within said chamber at least one object to be treated with electromagnetic radiation, said object extending over a distance in one direction in said chamber, means for delivering electromagnetic radiation to the object within said chamber to generate an electromagnetic field in the vicinity of said object, means including a duct transparent to said electromagnetic radiation extending within said chamber and through said field along said one direction a substantial distance at least equal to several wavelengths of the electromagnetic radiation, means for flowing a heatable material in said duct at a controlled rate of flow over said distance, the gain in thermal energy of said material along said substantial distance of duct being a measure of the average energy density of said field along the path of said duct, temperature insensitive means for measuring said gain in thermal energy along said duct, and means responsive to said measured gain in thermal energy for controlling the intensity of the electromagnetic radiation delivered to said object to maintain the energy density of said radiation along said path substantially constant.
Claim 2
Dependent Claim
196 words
Electromagnetic radiation treating apparatus comprising a treating chamber capable of confining an electromagnetic radiation field, means foR supporting within said chamber at least one object to be treated with electromagnetic radiation, said object extending over a distance in one direction in said chamber, means for delivering electromagnetic radiation to the object within said chamber to generate an electromagnetic field in the vicinity of said object, means including a duct transparent to said electromagnetic radiation extending within said chamber and through said field along said one direction a substantial distance at least equal to several wavelengths of the electromagnetic radiation, means for flowing a heatable material in said duct at a controlled rate of flow over said distance, the gain in thermal energy of said material along said substantial distance of duct being a measure of the average energy density of said field along the path of said duct, temperature insensitive means for measuring said gain in thermal energy along said duct, and means responsive to said measured gain in thermal energy for controlling the intensity of the electromagnetic radiation delivered to said object to maintain the energy density of said radiation along said path substantially constant.
Claim 3
Dependent Claim
38 words
The electromagnetic treating apparatus of claim 1 wherein said means for supporting within said chamber at least one object to be treated with electromagnetic radiation includes means for moving said object through said chamber in said one direction.
Claim 4
Dependent Claim
53 words
The electromagnetic treating apparatus according to claim 1 wherein said means responsive to said measured gain in thermal energy of said flowable material is a feedback control loop connecting said means for measuring the gain in thermal energy imparted to said flowable material with said means for delivering electromagnetic radiation to said object.
Claim 5
Dependent Claim
61 words
The electromagnetic treating apparatus of claim 3 wherein said feedback control loop includes an electrical time lag circuit which delays the response of the means for delivering the electromagnetic radiation to changes in said thermal energy for a time which is long comparable to the time of passage of said flowable material through the portion of said duct within said field.
Claim 6
Dependent Claim
27 words
The electromagnetic treating apparatus of claim 3 further including means for rendering said feedback control loop inoperable whenever said means for delivering electromagnetic radiation to said energy.
Claim 7
Dependent Claim
37 words
The electromagnetic treating apparatus of claim 1 wherein said means for delivering electromagnetic radiation to said chamber delivers microwave radiation thereto, and thermal insulation transparent to said microwave radiation is provided around said duct within said chamber.
Claim 8
Dependent Claim
20 words
The electromagnetic treating apparatus of claim 2 wherein said duct extends substantially from end to end of said treatment chamber.
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) | 1975-05-23 | 1975-11-22 | 1976-05-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-23 | 1979-11-22 | 1980-05-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-23 | 1983-11-22 | 1984-05-23 | $7700.00 | Window Closed / Lapsed |