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US4977302A
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Browning utensil for microwave ovens
Assignee: Evonik Operations GmbH
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Filing: 1989-12-20
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Granted: 1990-12-11
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Expires: 2009-12-20
Abstract
Abstract A browning utensil for microwave ovens which includes a base member of glass, ceramic or glass-ceramic with a metal containing coating applied to a surface of the base member. Applied over the metal containing coating is a layer of metal-free glazing formed of a glass frit. The metal containing coating also includes a glazing material which preferably is composed of the same ingredients as the metal-free glazing. The glazing material also preferably has essentially the same coefficient of thermal expansion between 20° and 300° C. as the material forming the base member.
Inventors
- 👤 Bernard Merigaud
- 👤 Michel Claus
- 👤 Robert Passerieux
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:34
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/64; H05B6/647; H05B6/6491; H05B6/6494; Y; Y10; Y10S; Y10S99/00; Y10S99/14
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
67 words
A browning utensil for microwave ovens, comprising: a support base; a metal-containing coating applied to said support base; a metal-free glazing applied to said metal-containing coating; and said metal containing coating, at the time of being applied to said support base, being formed of a mixture have 60 to 85% by weight of a metallic material and 15 to 40 % by weight of a non-metallic material.
Claim 2
Dependent Claim
67 words
A browning utensil for microwave ovens, comprising: a support base; a metal-containing coating applied to said support base; a metal-free glazing applied to said metal-containing coating; and said metal containing coating, at the time of being applied to said support base, being formed of a mixture have 60 to 85% by weight of a metallic material and 15 to 40 % by weight of a non-metallic material.
Claim 3
Dependent Claim
45 words
A browning utensil as recited in claim 1, wherein said metal containing coating and said metal-free glazing each are formed from a glass frit having essentially the same coefficient of thermal expansion for temperatures between 20° and 300° C. as that of the support base.
Claim 4
Dependent Claim
37 words
A browning utensil as recited in claim 2, wherein said support base is formed of a glass-ceramic material and said glass frit has a thermal expansion coefficient in the range of about 45-55×10 -7 K -1 .
Claim 5
Dependent Claim
34 words
A browning utensil as recited in claim 2, wherein said support base is a glass and said glass frit has a thermal expansion coefficient in the range of about 45-60×10 -7 K -1 .
Claim 6
Dependent Claim
35 words
A browning utensil as recited in claim 2, wherein said support base is formed of ceramic and said glass frit has a thermal expansion coefficient in the range of about 45-60×10 -7 K -1 .
Claim 7
Dependent Claim
36 words
A browning utensil as recited in claim 2, wherein said metal-containing coating includes a non-metallic glazing and said metal-free glazing applied to said metal-containing coating comprises essentially the same ingredients as that of said non-metallic glazing.
Claim 8
Dependent Claim
36 words
A browning utensil as recited in claim 1, wherein said metal-containing coating includes a non-metallic glazing and said metal-free glazing applied to said metal-containing coating comprises essentially the same ingredients as that of said non-metallic glazing.
Claim 9
Dependent Claim
21 words
A browning utensil as recited in claim 1, wherein said base support is formed of a material essentially transparent to microwaves.
Claim 10
Dependent Claim
18 words
A browning utensil as recited in claim 8, wherein said base support is formed of a glass material.
Claim 11
Dependent Claim
18 words
A browning utensil as recited in claim 8, wherein said base support is formed of a ceramic material.
Claim 12
Dependent Claim
18 words
A browning utensil as recited in claim 8, wherein said base support is formed of a glass-ceramic material.
Claim 13
Dependent Claim
41 words
A browning utensil as recited in claim 1, wherein said metallic material is selected from the group consisting of: (a) copper, (b) aluminum, (c) iron, (d) nickel, (e) tin, (f) zinc, or (g) an alloy containing one or more of (a-f).
Claim 14
Dependent Claim
85 words
A browning utensil as recited in claim 12, wherein said non-metallic glazing material is comprised of: 3to 15% by weight alkali oxide 5 to 20% by weight aluminum oxide 5 to 30% by weight boric oxide 40 to 70% by weight silicon oxide 0 to 10% by weight alkaline-earth oxide 0 to 20% by weight zinc oxide 0 to 15% by weight titanium oxide 0 to 40% by weight zirconium oxide 0 to 10% by weight tin oxide and 0 to 5% by weight fluoride.
Claim 15
Dependent Claim
85 words
A browning utensil as recited in claim 1, wherein said metal-free glazing is comprised of: 3 to 15% by weight alkali oxide 5 to 20% by weight aluminum oxide 5 to 30% by weight boric oxide 40 to 70% by weight silicon oxide 0 to 10% by weight alkaline-earth oxide 0 to 20% by weight zinc oxide 0 to 15% by weight titanium oxide 0 to 40% by weight zirconium oxide 0 to 10% by weight tin oxide and 0 to 5% by weight fluoride.
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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) | 1993-12-10 | 1994-06-11 | 1994-12-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-10 | 1998-06-11 | 1998-12-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-10 | 2002-06-11 | 2002-12-11 | $7700.00 | Window Closed / Lapsed |