US3604896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric self-cleaning oven circuit
Assignee: White Consolidated Industries Inc
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Filing: 1968-08-21
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Granted: 1971-09-14
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Expires: 1988-08-21
Abstract
Abstract A control circuit for a self-cleaning oven consisting of a switching system for alternatively connecting the bake and broil elements across the 236-volt powerline to generate heat for normal cooking operations, and for connecting the elements in parallel across the 236-volt line during the self-cleaning cycle. A semiconductor rectifier in series with the parallel-connected elements is utilized to control the rate of heat rise during the cleaning cycle to a predetermined cleaning temperature level, and to further limit power application thereafter. The switching system also controls temperature-regulating components and a safety circuit responsive to abnormal operation of the semiconductor rectifier to interrupt the cleaning cycle.
Inventors
- 👤 Carl L Anderson
- 👤 John T Lamb
- 👤 Ralph J Norris
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 08:55
CPC Classifications
F; F24; F24C; F24C14/00; F24C14/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
148 words
In an electric oven having a self-clean cycle, a circuit for controlling the generation of heat within the oven from a source of electrical AC power, comprising a bake-heating element for generating heat for normal baking applications, a broil-heating element, having greater heat dissipation than said bake element, for generating heat for normal broiling applications, a semiconductor diode for limiting the power applied to said heating elements, a switching device connected to said heating elements and said diode, said switching device being operative in normal heating applications to alternatively connect said bakeand-broil heating elements directly to the source of power and in the self-clean cycle to connect said heating elements in parallel with each other and in series with said diode to the source of power, and means responsive to failure of said diode for disconnecting said heating elements from the source of power in the self-clean cycle.
Claim 2
Dependent Claim
148 words
In an electric oven having a self-clean cycle, a circuit for controlling the generation of heat within the oven from a source of electrical AC power, comprising a bake-heating element for generating heat for normal baking applications, a broil-heating element, having greater heat dissipation than said bake element, for generating heat for normal broiling applications, a semiconductor diode for limiting the power applied to said heating elements, a switching device connected to said heating elements and said diode, said switching device being operative in normal heating applications to alternatively connect said bakeand-broil heating elements directly to the source of power and in the self-clean cycle to connect said heating elements in parallel with each other and in series with said diode to the source of power, and means responsive to failure of said diode for disconnecting said heating elements from the source of power in the self-clean cycle.
Claim 3
Dependent Claim
143 words
A circuit as set forth in claim 1, wherein said disconnecting means comprises a second rectifier connected from between the junction of said semiconductor diode and said heating elements to the source of power, in a polarity to oppose current flow from said diode, an element in series connection with said second rectifier, said element being responsive to excessive current flow to prevent further current flow therethrough, and a relay in parallel connection with said second rectifier, said relay having contacts in series connection with said heating elements and energizable in response to current flow through said diode to close said contacts, said second rectifier operative in response to a shorted condition of said diode for conducting excessive current flow through said element, thereby causing deenergization of said relay, opening of said contacts and disconnection of said heating elements from the power source.
Claim 4
Dependent Claim
48 words
A circuit as set forth in claim 2 wherein said element is a resistor for limiting current flow to said relay, said resistor having only sufficient wattage rating to accommodate current flow to said relay and being overloaded to destruction by excessive current flow from said second rectifier.
Claim 5
Dependent Claim
139 words
In an electronic oven, a circuit for controlling the application of power from a source to heating elements for normal and self-cleaning oven cycles, comPrising a bake-heating element, a broil-heating element, a semiconductor diode, a high-temperature thermostat responsive to heat within the oven, a variable thermostat responsive to normal cooking heat within the oven, said thermostats being in series connection with the source of power and said heating elements, and means, in the first instance, for alternatively connecting said heating elements to the source of power and, in the second instance, for connecting said heating elements in parallel to the source of power in series with said semiconductor diode and for shunting said variable thermostat, thereby to generate heat for the self-cleaning cycle, said high-temperature thermostat being operative in the second instance to limit the heat in the oven.
Claim 6
Dependent Claim
139 words
In an electronic oven, a circuit for controlling the application of power from a source to heating elements for normal and self-cleaning oven cycles, comPrising a bake-heating element, a broil-heating element, a semiconductor diode, a high-temperature thermostat responsive to heat within the oven, a variable thermostat responsive to normal cooking heat within the oven, said thermostats being in series connection with the source of power and said heating elements, and means, in the first instance, for alternatively connecting said heating elements to the source of power and, in the second instance, for connecting said heating elements in parallel to the source of power in series with said semiconductor diode and for shunting said variable thermostat, thereby to generate heat for the self-cleaning cycle, said high-temperature thermostat being operative in the second instance to limit the heat in the oven.
Claim 7
Dependent Claim
29 words
A circuit as set forth in claim 4 further including means responsive to abnormal conduction of said semiconductor diode for interrupting the application of power to said heating elements.
Claim 8
Dependent Claim
108 words
An electric self-cleaning oven circuit for generating heat within an oven enclosure from a source of electrical power comprising first and second electrical heaters of different wattage ratings corresponding respectively to bake-and-broil heating elements of a conventional oven, said heaters adapted for alternative connection to the line-to-line voltage of the source of power in the bake-and-broil heating cycles respectively, means for connecting said heaters in parallel to the same voltage in the self-clean cycle and a single semiconductor diode in series connection with said parallel-connected heaters in the self-clean cycle for periodically limiting the voltage applied thereto, thereby to control the rate of heat rise within the oven.
Claim 9
Dependent Claim
108 words
An electric self-cleaning oven circuit for generating heat within an oven enclosure from a source of electrical power comprising first and second electrical heaters of different wattage ratings corresponding respectively to bake-and-broil heating elements of a conventional oven, said heaters adapted for alternative connection to the line-to-line voltage of the source of power in the bake-and-broil heating cycles respectively, means for connecting said heaters in parallel to the same voltage in the self-clean cycle and a single semiconductor diode in series connection with said parallel-connected heaters in the self-clean cycle for periodically limiting the voltage applied thereto, thereby to control the rate of heat rise within the oven.
Claim 10
Dependent Claim
27 words
The circuit as set forth in claim 6 wherein said limiting means is responsive to the line-to-line voltage to apply approximately one-half the power to said elements.
Claim 11
Dependent Claim
157 words
An electric self-cleaning oven circuit for generating heat within an oven enclosure from a source of electrical power, comprising first and second electrical heaters of different wattage ratings corresponding respectively to bake-and-broil heating elements of a conventional oven, said heaters adapted for alternative connection to the line-to-line voltage of the source of power in the bake-and-broil heating cycles, respectively, means for connecting said heaters in parallel to the same voltage in the self-clean cycle, a semiconductor rectifier in series connection with said parallel-connected heaters in the self-clean cycle for periodically limiting the voltage applied thereto to control the rate of heat rise within the oven, first and second thermostatic switches in series connection with said parallel-connected heaters and said rectifier, said first thermostatic switch being adjustable and operative to control heat within the oven, said second thermostatic switch being operative to control maximum oven temperature, and means for shunting said first thermostatic switch in the self-clean cycle.
Claim 12
Dependent Claim
157 words
An electric self-cleaning oven circuit for generating heat within an oven enclosure from a source of electrical power, comprising first and second electrical heaters of different wattage ratings corresponding respectively to bake-and-broil heating elements of a conventional oven, said heaters adapted for alternative connection to the line-to-line voltage of the source of power in the bake-and-broil heating cycles, respectively, means for connecting said heaters in parallel to the same voltage in the self-clean cycle, a semiconductor rectifier in series connection with said parallel-connected heaters in the self-clean cycle for periodically limiting the voltage applied thereto to control the rate of heat rise within the oven, first and second thermostatic switches in series connection with said parallel-connected heaters and said rectifier, said first thermostatic switch being adjustable and operative to control heat within the oven, said second thermostatic switch being operative to control maximum oven temperature, and means for shunting said first thermostatic switch in the self-clean cycle.
Claim 13
Dependent Claim
59 words
The circuit as set forth in claim 8 wherein said shunting means and said means for connecting said heaters comprise a manually operable switch having a plurality of normally open contacts selectively connected to said heaters, said rectifier and said first thermostatic switch, said manual switch being adapted to selectively close said contacts in bake, broil and self-clean cycles.
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) | 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 |