# US 7,744,789 B2 · Method for curing a thick, non-uniform rubber article

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 7,744,789 B2
- Document ID: US7744789B2
- Status: Granted
- Kind: B2
- Application number: 11/711,214
- Filed: 2007-02-27
- Published: 2007-07-05
- Granted: 2010-06-29
- Earliest claimed: 2005-09-02
- Assignees: Michlein Recherche et Technique S.A.; Societe detechnologie Michelin
- Inventors: I. Douglas Greenwell; Michael J. Luneau; Donald Faulkner
- Web page: https://patentgrep.com/patent/US7744789B2

## CPC

- B29D 30/0606: {Vulcanising moulds not integral with vulcanising presses (for solid tyres B29D30/02)}
- B29D 30/0601: {Vulcanising tyres; Vulcanising presses for tyres}
- B29D 2030/0677: {Controlling temperature differences}
- B29K 2105/24: crosslinked or vulcanised
- B29L 2030/00: Pneumatic or solid tyres or parts thereof {(conveyor belts B29L2031/7092; drive belts B29L2031/7094; fourdrinier belts B29L2031/733)}
- B29D: PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE (making granules B29B9/00; making preforms B29B11/00)
- B29K: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR {MOULDS, } REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES

## Abstract

Finite element analysis or thermocouple probes are used to determine the state of cure for each zone of a non-uniform, thick rubber article, such as a large tire or a tread for a tire. From this knowledge of those cure-limiting zones, heat transfer elements are added to the mold to enhance the transfer of heat into these cure-limiting zones and to provide a more optimum cure. The use of heat transfer pins and/or mini-sipes are an efficient and practical means of reducing total cure time in the press and optimizing cure state without substantially affecting the performance of the article such as the tire. Reductions in cure time of 10% or more are demonstrated.

## Claims

### Claim 1

A method of curing a non-uniform, thick rubber article in a mold comprising the steps of:
predetermining the cure rates of the article in its parts to determine one or more cure-limiting parts;
selecting one or more cure-limiting parts;
inserting one or more pin heat transfer elements into the article, the one or more heat transfer elements protruding outward from an inner surface of the mold into the article at said selected cure-limiting parts;
placing the article inside the mold;
applying heat to the article and the one or more heat transfer elements until the article reaches a defined state of cure; and
removing the article from the mold;
wherein the cured article has a calculated percent reduction in the surface area of the one or more selected cure-limiting parts of 8% or less.

### Claim 2 (depends on 1)

The method of claim 1, wherein the article is a large tire.

### Claim 3 (depends on 2)

The method of claim 2, wherein the tire is a truck tire.

### Claim 4 (depends on 1)

The method of claim 1, wherein the article is a tread for a tire.

### Claim 5 (depends on 1)

The method of claim 1, wherein the step of inserting the one or more pin heat transfer elements further comprises:
inserting the one or more of the heat transfer elements at a depth of between 5% and 80% of the thickness of said selected cure-limiting parts.

### Claim 6 (depends on 5)

The method of claim 5, wherein the article is a large tire and the one or more cure-limiting parts include a tread block.

### Claim 7

A method of making a mold for curing a non-uniform, thick rubber article, the method comprising the steps of:
predetermining the curing rates of substantially all portions of the article to be inserted into the mold,
selecting one or more cure-limiting parts of the article,
affixing one or more pin heat transfer elements to protrude from the Inner surface of the mold, and
arranging the one or more heat transfer elements affixed to the mold so that the elements are aligned to insert within the selected cure-limiting parts of the article when the article is cured in the mold.

### Claim 8 (depends on 1)

The method of claim 1, further comprising obtaining a calculated percent reduction in rigidity of the selected one or more cure-limiting parts of 4% or less.