# US 8,569,665 B2 · Cookware with tarnish protected copper exterior

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- Number: US 8,569,665 B2
- Document ID: US8569665B2
- Status: Granted
- Kind: B2
- Application number: 11/550,205
- Filed: 2006-10-17
- Published: 2008-05-01
- Granted: 2013-10-29
- Earliest claimed: 2006-10-17
- Assignees: Meyer Intellectual Properties Limited
- Applicants: Stanley Kin-Sui Cheng
- Inventors: Stanley Kin-Sui Cheng
- Web page: https://patentgrep.com/patent/US8569665B2

## CPC

- A47J 36/02: Selection of specific materials, e.g. heavy bottoms with copper inlay or with insulating inlay
- A47J: KITCHEN EQUIPMENT; COFFEE MILLS; SPICE MILLS; APPARATUS FOR MAKING BEVERAGES

## Abstract

An article of cookware in the form of a cooking vessel exposes only a portion of a copper inner layer on the upper portion of the exterior sidewall. The layer does not change color or tarnish as it sufficiently distal from the bottom of the cooking vessel that it is not subject to direct heat and oxidation during normal use. The unique bright color of the native copper is further protected from tarnish caused by fingerprint by a protective coating that can withstand moderate heating.

## Claims

### Claim 1

An article of cookware comprising:
a) inner lining having;
i) a bottom surface,
ii) surrounding sidewalls extending upward there from to a rim to form an inner fluid containing vessel, the rim of said inner fluid containing vessel defining the upper extent of the rim of the article of cookware,
b) an outer cladding layer that covers the exterior of the bottom surface of said inner lining and extends upward there from to cover a bottom portion of the exterior of the surrounding sidewalls of said inner lining, wherein said outer cladding was in substantially the same shape before attachment to cover the exterior bottom surface of the inner lining, extending upward to a position substantially below the rim,
c) a copper cladding that covers at least the portion of the surrounding sidewalls of said inner lining not covered by said outer cladding to form a portion of the visible external surface of the cookware article by extending upward to join the rim of said inner lining,
wherein said exposed copper cladding is covered by a protective coating that prevents the visible discoloration thereof.

### Claim 2 (depends on 1)

An article of cookware according to claim 1 wherein the protective coating is an organic coating.

### Claim 3 (depends on 1)

An article of cookware according to claim 1 wherein the protective coating is a transition metal compound selected from the group consisting of metal nitrides, oxy-nitrides and carbides.

### Claim 4

An article of cookware comprising:
a) inner lining having;
i) a bottom surface,
ii) surrounding sidewalls extending upward there from to a rim to form an inner fluid containing vessel, the rim of said inner fluid containing vessel defining the upper extent of the rim of the article of cookware,
b) an outer cladding layer that covers the exterior of the bottom surface of said inner lining and extends upward there from to cover a bottom portion of the exterior of the surrounding sidewalls of said inner lining, wherein said outer cladding was in substantially the same shape before attachment to cover the exterior bottom surface of the inner lining, extending upward to a position substantially below the rim,
c) a copper appearing cladding that covers at least the portion of the surrounding sidewalls of said inner lining not covered by said outer cladding to form a portion of the visible external surface of the cookware article by extending upward to join the rim of said inner lining,
wherein the copper appearing cladding comprises a transition metal compound selected from the group consisting of metal nitrides, oxy-nitrides and carbides.

### Claim 5 (depends on 4)

An article of cookware according to claim 4 wherein said exposed copper appearing cladding is covered by a protective coating that prevents the visible discoloration thereof.

### Claim 6 (depends on 5)

An article of cookware according to claim 5 wherein the protective coating is an organic coating.

### Claim 7

An article of cookware comprising:
a) inner lining having;
i) a bottom surface,
ii) surrounding sidewalls extending upward there from to a rim to form an inner fluid containing vessel, the rim of said inner fluid containing vessel defining the upper extent of the rim of the article of cookware,
b) an outer cladding layer that covers the exterior of the bottom surface of said inner lining and extends upward there from to cover a bottom portion of the exterior of the surrounding sidewalls of said inner lining, wherein said outer cladding was in substantially the same shape before attachment to cover the exterior bottom surface of the inner lining, extending upward to a position substantially below the rim,
c) a copper cladding that covers at least the portion of the surrounding sidewalls of said inner lining not covered by said outer cladding to form a portion of the visible external surface of the cookware article by extending upward to join the rim of said inner lining,
wherein said outer cladding layer has a thickness of at least about 0.6 mm.

### Claim 8

An article of cookware comprising:
a) inner lining having;
i) a bottom surface,
ii) surrounding sidewalls extending upward there from to a rim to form an inner fluid containing vessel, the rim of said inner fluid containing vessel defining the upper extent of the rim of the article of cookware,
b) an outer cladding layer that covers the exterior of the bottom surface of said inner lining and extends upward there from to cover a bottom portion of the exterior of the surrounding sidewalls of said inner lining, wherein said outer cladding was in substantially the same shape before attachment to cover the exterior bottom surface of the inner lining, extending upward to a position substantially below the rim,
c) a copper appearing cladding that covers at least the portion of the surrounding sidewalls of said inner lining not covered by said outer cladding to form a portion of the visible external surface of the cookware article by extending upward to join the rim of said inner lining, wherein said outer cladding layer has a thickness of at least about 0.6 mm.