US3789189A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical cooking appliance
Assignee: E G D ELEKTRO GERATE BLANC und
•
Filing: 1972-08-22
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Granted: 1974-01-29
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Expires: 1992-08-22
Abstract
Abstract An electrical cooking appliance has an upper glass-ceramic plate for supporting the cooking vessels to be heated. A heating unit is disposed below the or each heating zone of the plate and comprises a spiral heating element disposed in a supporting bowl. Leak springs outside the bowl act on the heating element by way of cross pieces inside the bowl and press the heating element by a flat surface thereof into good heat-conductive relationship with the underside of the glass-ceramic plate. The heating element is in two parts with a temperature sensing element disposed therebetween, the latter also being pressed against the underside of the plate.
Inventors
- 👤 K Fischer
- 👤 G Gossler
- 👤 R Kicherer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:59
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/68; H05B3/76; F; F24; F24C; F24C7/00; F24C7/06; F24C7/067; H05B3/74; H05B3/748
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
210 words
In an electrical cooking appliance, the combination comprising: a highly heat-shock resistant, glass-ceramic upper plate having at least one cooking zone for receiving and supporting a cooking vessel to be heated; a separate heating unit mounted beneath said plate at each cooking zone, each unit including (1) a supporting bowl, (2) a heating element disposed in said bowl adjacent said plate and having a metallic sheath, a heating wire enclosed in said sheath and an electrical insulation material between said heating wire and said sheath, said sheath being flattened at the side adjacent said plate to provide a direct area contact between said heating element and said pLate, said heating element having a small cross-section and being flexible for heat conductive contact with said plate, and (3) means for supporting said heating element within said supporting bowl for direct contact of said heating element with said plate; and means for detachably mounting said heating unit below said plate including spring means for urging said heating unit support bowl against said plate and resilient means operative between said bowl and said plate, said heating element being resiliently pressed into heat conductive contact with said plate whereby each separate heating unit may be independently installed or removed from beneath said upper plate.
Claim 2
Dependent Claim
210 words
In an electrical cooking appliance, the combination comprising: a highly heat-shock resistant, glass-ceramic upper plate having at least one cooking zone for receiving and supporting a cooking vessel to be heated; a separate heating unit mounted beneath said plate at each cooking zone, each unit including (1) a supporting bowl, (2) a heating element disposed in said bowl adjacent said plate and having a metallic sheath, a heating wire enclosed in said sheath and an electrical insulation material between said heating wire and said sheath, said sheath being flattened at the side adjacent said plate to provide a direct area contact between said heating element and said pLate, said heating element having a small cross-section and being flexible for heat conductive contact with said plate, and (3) means for supporting said heating element within said supporting bowl for direct contact of said heating element with said plate; and means for detachably mounting said heating unit below said plate including spring means for urging said heating unit support bowl against said plate and resilient means operative between said bowl and said plate, said heating element being resiliently pressed into heat conductive contact with said plate whereby each separate heating unit may be independently installed or removed from beneath said upper plate.
Claim 3
Dependent Claim
18 words
An electrical cooking appliance according to claim 1, which further comprises protective conductor means connected to said sheath.
Claim 4
Dependent Claim
21 words
An electrical cooking appliance according to claim 1, in which said supporting bowl has an interior surface formed as a reflector.
Claim 5
Dependent Claim
24 words
An electrical cooking appliance according to claim 1, in which said heating element direct area contact occupies approximately 80 percent of said cooking zone.
Claim 6
Dependent Claim
21 words
An electrical cooking appliance according to claim 1, in which said heating element is wound in the form of a spiral.
Claim 7
Dependent Claim
19 words
An electrical cooking appliance according to claim 1, in which said heating element has a generally triangular cross section.
Claim 8
Dependent Claim
38 words
An electrical cooking appliance according to claim 1, in which said heating element has in cross section outer dimensions of less than 5 mm parallel to said plate and of less than 4 mm perpendicular to said plate.
Claim 9
Dependent Claim
29 words
An electrical cooking appliance according to claim 1, in which said supporting bowl is circular and defines an annular channel encircling an unheated central zone of the heating unit.
Claim 10
Dependent Claim
32 words
An electrical cooking appliance according to claim 3, in which said supporting bowl comprises good heat-conductive material and its wall thickness is high in order that its temperature shall be substantially uniform.
Claim 11
Dependent Claim
33 words
An electrical cooking appliance according to claim 1, in which said supporting bowl has an outer surface formed as a non-reflector so that it shall have the greatest possible radiation-absorption ratio epsilon .
Claim 12
Dependent Claim
19 words
An electrical cooking appliance according to claim 10, in which said outer surface of said supporting bowl is roughened.
Claim 13
Dependent Claim
20 words
An electrical cooking appliance according to claim 10, in which said outer surface of said supporting bowl is darkly coloured.
Claim 14
Dependent Claim
19 words
An electrical cooking appliance according to claim 10, in which said outer surface of said supporting bowl is oxidized.
Claim 15
Dependent Claim
48 words
An electrical cooking appliance according to claim 1, in which said heating element support means includes a plurality of cross pieces disposed in said bowl and supporting said heating element, and resilient spring means acting individually against said cross pieces to urge said heating element against said plate.
Claim 16
Dependent Claim
90 words
An electrical cooking appliance according to claim 14, in which said heating element is wound in the form of a spiral and said cross pieces extend generally radially with respect to said spiral and in which each of said cross pieces comprises two adjacent generally vertical sheet metal parts having edges facing the heating element so formed that each sheet metal part supports every other turn of the heating element and every turn of the heating element is supported by a respective one only of the two sheet metal parts.
Claim 17
Dependent Claim
34 words
An electrical cooking appliance according to claim 14, in which guide means are provided in said supporting bowl and loosely locate said cross pieces so that the latter can tilt to a limited extent.
Claim 18
Dependent Claim
48 words
An electrical cooking appliance according to claim 14, in which said resilient spring means is adapted to exert a spring force urging said heating element against said plate with a pressure not substantially in excess of that necessary for large-area contact of said heating element with said plate.
Claim 19
Dependent Claim
32 words
An electrical cooking appliance according to claim 14, in which said resilient spring means comprise a plurality of leaf springs fastened to said supporting bowl and acting individually on said cross pieces.
Claim 20
Dependent Claim
63 words
An electrical cooking appliance according to claim 18, in which said resilient spring means comprises a coherent, star-shaped spring part spring material, which is attached centrally to said supporting bowl at the outside thereof and has arms which define said leaf springs, said bowl having apertures and said arms having free ends which extend through said apertures and individually engage said cross pieces.
Claim 21
Dependent Claim
56 words
An electrical cooking appliance according to claim 18, in which said leaf springs are mounted individually on said supporting bowl in the peripheral region of the outer surface of the latter and in which said supporting bowl has apertures, said leaf springs having free ends which extend through said apertures and individually engage said cross pieces.
Claim 22
Dependent Claim
34 words
An electrical cooking appliance according to claim 26, in which said resilient means comprises a resilient intermediate layer disposed between the outer edge region of said supporting bowl and the underside of said plate.
Claim 23
Dependent Claim
41 words
An electrical cooking appliance according to claim 5, in which said spiral wound heating element is in two parts leaving free a space between said heating element parts and in which a temperature sensor element is disposed in said free space.
Claim 24
Dependent Claim
52 words
An electrical cooking appliance according to claim 22, in which said free space is formed by a turn of the notional spiral defined by said heating element and in which said temperature sensor element is curved into the shape of a spiral turn and pressed resiliently against the underside of said plate.
Claim 25
Dependent Claim
37 words
An electrical cooking appliance according to claim 23, in which an undulating spacer plate is disposed in said free space to maintain said sensor element at a uniform distance from the adjacent turns of said heating element.
Claim 26
Dependent Claim
196 words
In an electrical cooking appliance, the combination comprising: a highly heat-shock resistant, glass-ceramic upper plate having at least one cooking zone for receiving and supporting a cooking vessel to be heated; a separate heating unit mounted beneath said plate at each cooking zone, each unit including (1) a supporting bowl, (2) a heating element disposed in said bowl adjacent said plate and having a metallic sheath, a heating wire enclosed in said sheath and an electrical insulation material between said heating wire and said sheath, said sheath being flattened at the side adjacent said plate to provide a direct area contact between said heating element and said plate, said heating element being flexible and having a small cross-section, and (3) means for resiliently supporting said heating element within said supporting bowl for resiliently biased direct contact of said heating element with said plate; and means for detachably mounting said heating unit below said plate including spring means for urging said heating unit support bowl against said plate, said heating element being resiliently pressed into heat conductive contact with said plate whereby each separate heating unit may be independently installed or removed from beneath said upper plate.
Claim 27
Dependent Claim
196 words
In an electrical cooking appliance, the combination comprising: a highly heat-shock resistant, glass-ceramic upper plate having at least one cooking zone for receiving and supporting a cooking vessel to be heated; a separate heating unit mounted beneath said plate at each cooking zone, each unit including (1) a supporting bowl, (2) a heating element disposed in said bowl adjacent said plate and having a metallic sheath, a heating wire enclosed in said sheath and an electrical insulation material between said heating wire and said sheath, said sheath being flattened at the side adjacent said plate to provide a direct area contact between said heating element and said plate, said heating element being flexible and having a small cross-section, and (3) means for resiliently supporting said heating element within said supporting bowl for resiliently biased direct contact of said heating element with said plate; and means for detachably mounting said heating unit below said plate including spring means for urging said heating unit support bowl against said plate, said heating element being resiliently pressed into heat conductive contact with said plate whereby each separate heating unit may be independently installed or removed from beneath said upper plate.
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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) | 1977-01-28 | 1977-07-30 | 1978-01-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-28 | 1981-07-30 | 1982-01-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-28 | 1985-07-30 | 1986-01-29 | $7700.00 | Window Closed / Lapsed |