US3854024A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Environmental temperature control system
Assignee: DCA Food Industries Inc
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Filing: 1974-02-01
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Granted: 1974-12-10
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Expires: 1994-02-01
Abstract
Abstract A combined microwave-infrared oven having heating elements mounted therein is provided with an air-sampling manifold protected from microwave exposure by traps and located external to the oven which includes an air blower for circulating air from the microwave oven through the air-sampling manifold. A temperature sensor is mounted within the air-sampling manifold and when the air temperature of the microwave cavity reaches a desired level, the temperature sensor controls will operate to shut-off power to the heating elements and when it reaches a differential temperature below this level will operate to supply power to the heating elements. The system is also provided with a control device to regulate the power output level of the heating elements independent of the temperature sensor serving to minimize the frequency of undesirable on-off cycling of the heating elements as caused by the operation of the temperature sensor.
Inventors
- 👤 H Kaufman
- 👤 J Mccarthy
- 👤 R Schiffmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 08:08
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/647; H05B6/6482; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1927; G05D23/193; G05D23/1931; G05D23/275; H05B6/6447; H05B6/645; H05B6/78; H05B6/782
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
139 words
In a microwave system, an enclosure defining a microwave cavity having heating means mounted therein, means defining an air-sampling zone external to said microwave cavity, means including microwave traps for connecting said air-sampling zone to said microwave cavity, means for drawing air from said microwave cavity into said air-sampling zone and returning air to said microwave cavity, a thermostatic control operatively connected to a power source and in controlling relation to said heating means and including a temperature sensor in said airsampling zone operable to sense the temperature of the air passing through said air-sampling zone without being effected by the microwave energy in said microwave cavity, and said thermostatic control being responsive to said temperature sensor and controlling operation of said heating means to maintain the temperature of the air in said microwave cavity at a desired level.
Claim 2
Dependent Claim
139 words
In a microwave system, an enclosure defining a microwave cavity having heating means mounted therein, means defining an air-sampling zone external to said microwave cavity, means including microwave traps for connecting said air-sampling zone to said microwave cavity, means for drawing air from said microwave cavity into said air-sampling zone and returning air to said microwave cavity, a thermostatic control operatively connected to a power source and in controlling relation to said heating means and including a temperature sensor in said airsampling zone operable to sense the temperature of the air passing through said air-sampling zone without being effected by the microwave energy in said microwave cavity, and said thermostatic control being responsive to said temperature sensor and controlling operation of said heating means to maintain the temperature of the air in said microwave cavity at a desired level.
Claim 3
Dependent Claim
52 words
A microwave system according to claim 1 further including means operatively connected to said thermostatic control and operatively connected to said power source foR regulating the power output level of said heating means independent of said thermostatic control by continuously enabling and then disabling the supply of power to said heating means.
Claim 4
Dependent Claim
37 words
A microwave system according to claim 2 wherein said regulating means includes a timer for setting predetermined time intervals and a regulating switch which is continuously opened and closed by said timer independent of said temperature sensor.
Claim 5
Dependent Claim
27 words
A microwave system according to claim 1 further including conveyor means for transporting products into and out of said microwave cavity to be exposed to microwave energy.
Claim 6
Dependent Claim
26 words
A microwave system according to claim 1 wherein said air-sampling zone includes an air-sampling manifold, said microwave traps connecting said air-sampling manifold to said microwave cavity.
Claim 7
Dependent Claim
35 words
A microwave system according to claim 5 wherein said drawing and returning means includes a motor-driven air blower connected to said air-sampling manifold for circulating air through said microwave cavity at a minimum air velocity.
Claim 8
Dependent Claim
39 words
A microwave system according to claim 1 wherein said heating means includes at least two heating elements mounted within said enclosure and manually operable switches for selectively connecting either or both of said heating elements to said thermostatic control.
Claim 9
Dependent Claim
16 words
A microwave system according to claim 7 wherein said heating elements are of the infrared type.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-09 | 1978-06-10 | 1978-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-09 | 1982-06-10 | 1982-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-09 | 1986-06-10 | 1986-12-10 | $7700.00 | Window Closed / Lapsed |