# US 5,702,546 A · Pneumatic tires having a tread of an oriented rubber

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- Number: US 5,702,546 A
- Document ID: US5702546A
- Status: Granted
- Kind: A
- Application number: 08/555,326
- Filed: 1995-11-08
- Granted: 1997-12-30
- Earliest claimed: 1994-11-08
- Assignees: Bridgestone Corporation
- Inventors: Kenji Itoh; Toru Sato
- Web page: https://patentgrep.com/patent/US5702546A

## CPC

- B60C 11/18: of strip form, e.g. metallic combs, rubber strips of different wear resistance (B60C11/20 takes precedence)
- B29C 48/07: Flat, e.g. panels
- B29C 48/08: flexible, e.g. films
- B29C 48/12: Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
- B29C 48/305: having a wide opening, e.g. for forming sheets
- B60C 11/00: Tyre tread bands; Tread patterns; Anti-skid inserts
- B29L 2030/002: {Treads}
- Y10T 152/10513: Tire reinforcement material characterized by short length fibers or the like
- B60C: VEHICLE TYRES; TYRE INFLATION; TYRE CHANGING; CONNECTING VALVES TO INFLATABLE ELASTIC BODIES IN GENERAL; DEVICES OR ARRANGEMENTS RELATED TO TYRES
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B29L: INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULAR ARTICLES
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A pneumatic tire comprises a tread made from an oriented rubber so that a modulus ratio of 300% tensile modulus in a circumferential direction of the tire to 300% tensile modulus in a widthwise direction of the tire is larger by at least 0.1 times in a central region of the tread than in each side region of the tread.

## Claims

### Claim 1

In a pneumatic tire comprising; a tread made from an oriented rubber sheet having a modulus ratio of 300% tensile modulus in a circumferential direction of the tire to a 300% tensile modulus in a widthwise direction of the tire in a central region of the tread which is larger by at least +0.1 times than corresponding modulus ratios in each side region of the tread, and the modulus ratio is 1.1-1.5 in the central region of the tread and 0.9-1.2 in the side region of the tread, and the rubber sheet is made by a process of extruding rubber by an extruder having an extrusion head including orientation controlling flow-paths consisting of a squeezing path to orient the rubber in said central region of said rubber sheet in the circumferential direction of the tire and spreading paths located on both sides of the squeezing path to orient the rubber in each side region in the widthwise direction of the tire.

### Claim 2 (depends on 1)

A pneumatic tire according to claim 1, wherein the central region of the tread is located at a zone centering around a tread center and corresponding to 0.3-0.7 times a width of the tread.

### Claim 3 (depends on 2)

A pneumatic tire according to claim 2 wherein said tire is a motorcycle tire and said central region of said tread is 0.5 of an overall treadwidth.

### Claim 4 (depends on 2)

A pneumatic tire according to claim 2 wherein said rubber sheet comprises a composition of a rubber, carbon black, oil, a vulcanizing agent, vulcanizing accelerator, accelerator activator, antioxidant and plasticizer.

### Claim 5 (depends on 4)

A pneumatic tire according to claim 4 wherein said rubber is styrene butadiene rubber.

### Claim 6 (depends on 2)

A pneumatic tire according to claim 2 wherein said rubber is a high polymer selected from the group consisting of thermoplastic resins and thermosetting resins and said composition further comprises a filler.

### Claim 7 (depends on 1)

A pneumatic tire according to claim 1 wherein said tire is a passenger car tire and said central region of said tread is 0.6 of an overall treadwidth.