US3784788A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric liquid boiling apparatus having an electronic temperature sensor control
Assignee: HARVEY PAUL ALWYN 78 SOUTH TERRACE SURBITON SURREY
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Filing: 1972-05-04
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Granted: 1974-01-08
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Expires: 1992-05-04
Abstract
Abstract An electric liquid boiling apparatus, particularly an electric kettle, having an automatic cut-out operated by an electronic temperature sensor, e.g. a thermistor which is subjected to vapour when the liquid boils.
Inventors
- 👤 D Fourny
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 05:05
CPC Classifications
H; H05; H05B; H05B1/00; H05B1/02; H05B1/0227; H05B1/0252; H05B1/0258; H05B1/0269; A; A47; A47J; A47J27/00; A47J27/21; A47J27/21008; A47J27/21058; A47J27/21091; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1906; G05D23/1909; G05D23/20; G05D23/24; H05B2213/00; H05B2213/07
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
155 words
In an apparatus for boiling liquid comprising a container for the liquid, said container having an opening therein through which hot liquid vapor is ejected when the liquid boils, an electric heating element in the container for heating the liquid therein and means for carrying electric current to said heating element, the improvement comprising a current-controlled switch device in series with said current carrying means; a control circuit having an input and an output, said output being connected to the current controlled switch device; and an electronic temperature sensor means having a high temperature coefficient positioned so as to be subjected to said ejected hot liquid vapor when the liquid in the container boils and being electrically connected to said input of said control circuit, whereby when the liquid boils, the electronic temperature sensor is heated and the control circuit operates the current-controlled switch device to cut off the heating current for the heating element.
Claim 2
Dependent Claim
155 words
In an apparatus for boiling liquid comprising a container for the liquid, said container having an opening therein through which hot liquid vapor is ejected when the liquid boils, an electric heating element in the container for heating the liquid therein and means for carrying electric current to said heating element, the improvement comprising a current-controlled switch device in series with said current carrying means; a control circuit having an input and an output, said output being connected to the current controlled switch device; and an electronic temperature sensor means having a high temperature coefficient positioned so as to be subjected to said ejected hot liquid vapor when the liquid in the container boils and being electrically connected to said input of said control circuit, whereby when the liquid boils, the electronic temperature sensor is heated and the control circuit operates the current-controlled switch device to cut off the heating current for the heating element.
Claim 3
Dependent Claim
14 words
Apparatus as claimed in claim 1 wherein the temperature sensor means is a thermistor.
Claim 4
Dependent Claim
18 words
Apparatus as claimed in claim 1 wherein the temperature sensor means is situated outside said opening adjacent thereto.
Claim 5
Dependent Claim
51 words
Apparatus as claimed in claim 1 including a thermally conductive metal strip in thermal contact with said heating element and said electronic temperature sensor means, whereby said switch device is operative to break the current supply to the heating element both when the liquid boils and when the heating element overheats.
Claim 6
Dependent Claim
70 words
Apparatus as claimed in claim 1 including a second electronic temperature sensor means, said second sensor means being in thermal contact with said heating element, the two temperature sensor means being electrically connected in parallel so that heating of either operates the switch device, whereby said switch device is operative to break the current supply to the heating element both when the liquid boils and when the heating element overheats.
Claim 7
Dependent Claim
18 words
Apparatus as claimed in claim 1 wherein the switch device is an electromechanical relay which is manually resettable.
Claim 8
Dependent Claim
43 words
Apparatus as claimed in claim 6 wherein the control circuit comprises a transistor having an emitter-collector path connected to control the energization of the relay and a base emitter path connected to the said input to be controlled by said temperature sensor means.
Claim 9
Dependent Claim
56 words
Apparatus as claimed in claim 1 wherein said container is a kettle for boiling water, said kettle including a handle, the control circuit and switch deviCe being included in said handle, a duct in the handle communicating with said opening and with the air-space above the water, said duct having the temperature sensor means positioned therein.
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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) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |