Method for reducing the working temperature of a tire tread for vehicles and some tire treads capable of performing said method

• US 6,540,858 B1
• Filed: 10/07/1997
• Issued: 04/01/2003
• Est. Priority Date: 03/14/1997
• Status: Expired due to Term

• Current Assignee: Pirelli Coordinamento Pneumatici SpA (Pirelli & C SPA)
• Original Assignee: Pirelli Coordinamento Pneumatici SpA (Pirelli & C SPA)
• Inventors: Caretta, Renato, Nanni, Marco Nahmias
• Primary Examiner(s): Maki, Steven D.
• Application Number:
  US08/946,233
• Time in Patent Office: 2,002 Days
• Field of Search: 156/110.1, 156/123, 156/128.1, 152/209.R, 152/209.D, 152/209.A, 152/152.1, 152/DIG.2, 294/28
• US Class Current: 156/110.1
• CPC Class Codes: B60C 11/00 Tyre tread bands; Tread patterns; Anti-skid inserts
• CPC Class Codes: B60C 11/0058 with different cap rubber layers in the axial direction
• CPC Class Codes: B60C 11/0066 having an asymmetric arrangement
• CPC Class Codes: B60C 11/0075 with different base rubber layers in the axial direction
• CPC Class Codes: B60C 11/0083 characterised by the curvature of the tyre tread
• CPC Class Codes: B60C 11/02 Replaceable treads
• CPC Class Codes: B60C 11/0302 directional pattern, i.e. with main rolling direction
• CPC Class Codes: B60C 11/18 of strip form, e.g. metallic combs, rubber strips of different wear resistance B60C11/20 takes precedence
• CPC Class Codes: B60C 2011/0016 Physical properties or dimensions
• CPC Class Codes: B60C 2011/0374 Slant grooves, i.e. having an angle of about 5 to 35 degrees to the equatorial plane
• CPC Class Codes: B60C 2011/0388 provided at the equatorial plane
• CPC Class Codes: B60C 2200/10 for motorcycles, scooters or the like
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A method for reducing the working temperature of a tire tread for vehicles utilizing a tire tread comprising a first portion and a second portion. The first portion comprising 100 parts by weight of an elastomeric material, 40-120 parts by weight of a filler, comprising from 50 to 100% by weight of carbon black and from 0 to 50% of silica, and 3-40 parts by weight of at least a conventional additive. The second portion comprising 100 parts by weight of an elastomeric material, 40-120 parts by weight of a filler, comprising from 30 to 100% by weight of silica and from 0 to 70% of carbon black, and 3-40 parts by weight of at least a conventional additive. However, the silica content in the second portion is at least 20% higher than in the first portion. Tires wherein the area of the first portion exceeds 37.1% of the total area of the tire tread are also disclosed.

Claims

1. A vehicle tire having a tread band comprising:

a) a first portion comprising;

100 parts by weight of an elastomeric material, and

40-120 parts by weight of a filler comprising from 50 to 100% by weight of carbon black and from 0 to 50% by weight of silica, and

3-40 parts by weight of at least one additive;

b) a second portion comprising;

100 parts by weight of an elastomeric material, and

40-120 parts by weight of a filler comprising 100% by weight of silica, and

3-40 parts by weight of at least one additive,

said first portion and second portion defining respective portions of surface of said tread band,

wherein the surface area of said first portion is from 37.1% to 80% of the total area of the tread band, wherein said tread band has a first outside edge and a second outside edge, wherein said first portion encompasses the first outside edge and said second portion encompasses the second outside edge of said tread band, wherein there is only one boundary between the first portion and the second portion, wherein said first portion consists of one continuous circumferential band and said second portion consists of one continuous circumferential band and said first and second portions are axially side-by-side, and

wherein said second portion is mounted on a sidewall for facing the vehicle.

2. A tire according to claim 1, wherein the area of said first portion is of from 40 to 70% of the total area of the tread band.

3. A tire according to claim 1, wherein the area of according to said first portion is from 50 to 60% of the total area of the tread band.

4. A method comprising:

making a vehicle tire having a tread band having a reduced working temperature in operation over routes, comprising;

arranging the tread band on a tire carcass, the tread band having a composition comprising;

a) a first portion comprising;

100 parts by weight of an elastomeric material, and

40-120 parts by weight of a filler comprising from 50 to 100% by weight of carbon black and from 0 to 50% by weight of silica, and

3-40 parts by weight of at least one additive;

b) a second portion comprising;

100 parts by weight of an elastomeric material, and

40-120 parts by weight of a filler comprising 100% by weight of silica, and

3-40 parts by weight of at least one additive,

said first portion and second portion defining respective portions of surface of said tread band, wherein the area of the first portion is from 37.1 to 80% of the total area of then tread band, wherein said tread band has a first outside edge and a second outside edge, wherein said first portion encompasses the first outside edge and said second portion encompasses the second outside edge of said tread band, wherein there is only one boundary between the first portion and the second portion, and wherein said first portion consists of one continuous circumferential band and said second portion consists of one continuous circumferential band and said first and second portions are axially side-by-side,

providing the tread band with a tread pattern adapted to affect the driving characteristics of said tire during operation over routes, and

mounting the tire on a vehicle so that the second portion is on the sidewall facing the vehicle,

wherein the working temperature of the first portion of said tire having a reduced working temperature is less than a working temperature of a corresponding portion of a second tire having a tread band, wherein the second tire is the same as said tire having a reduced working temperature except that the tread band of the second tire only has a composition which is the same as the composition of the first portion.

5. A method according to claim 4, wherein said first and second edges being on opposed sides of an equator of said tire.

6. A method according to claim 4, wherein the area of said first portion is of from 40 to 70% of the total area of the tread band.

7. A method according to claim 4, wherein the area of said first portion is from 50 to 60% of the total area of the tread band.

8. A four wheeled motor vehicle comprising a vehicle tire having a tread band comprising:

a) a first portion comprising;

100 parts by weight of an elastomeric material, and

40-120 parts by weight of a filler comprising from 50 to 100% by weight of carbon black and from 0 to 50% by weight of silica, and

3-40 parts by weight of at least one additive;

b) a second portion comprising;

100 parts by weight of an elastomeric material, and

40-120 parts by weight of a filler comprising 100% by weight of silica, and

3-40 parts by weight of at least one additive,

said first portion and second portion defining respective portions of surface of said tread band,

wherein the surface area of said first portion is from 37.1% to 80% of the total area of the tread band, wherein said tread band has a first outside edge and a second outside edge, wherein said first portion encompasses the first outside edge and said second portion encompasses the second outside edge of said tread band, wherein there is only one boundary between the first portion and the second portion, wherein said first portion consists of one continuous circumferential band and said second portion consists of one continuous circumferential band and said first and second portions are axially side-by-side, and

wherein said second portion of the tire is mounted on the sidewall facing the vehicle.