Tire

Patent metadata

Field	Value
Publication number	US-2022016933-A1
Application number	US-202117358004-A
Country	US
Kind code	A1
Filing date	Jun 25, 2021
Priority date	Jul 14, 2020
Publication date	Jan 20, 2022
Grant date	—

Abstract

A tire comprises a tread portion provided with a band composed of at least one band cord wound spirally and circumferentially of the tire and embedded in the tread portion. When a band cord piece is taken out from the above-said at least one band cord embedded in the tread portion and measured for the length, a length Lb is equal to or smaller than a length La at least in a part of the tread portion, where the length Lb is measured at a first point of time after the band cord piece has been taken out, and the length La is measured at a second point of time after the first point of time.

First claim

1 . A tire comprising a tread portion provided with a band composed of at least one band cord wound spirally and circumferentially of the tire and embedded in the tread portion, wherein
when a band cord piece is taken out from said at least one band cord embedded in the tread portion and measured for the length, at least in a part of the tread portion, a length Lb is equal to or smaller than a length La, where the length Lb is measured at a first point of time after the band cord piece has been taken out, and the length La is measured at a second point of time after the first point of time.

2 . The tire according to claim 1 , wherein
the second point of time is 24 hours after the band cord piece has been taken out.

3 . The tire according to claim 2 , wherein
a difference (Lb−La) of the length Lb from the length La is in a range from −5.0% to 0.0% of the length Lb.

4 . The tire according to claim 3 , wherein
the difference (Lb−La) is in a range from −4.5% to 0.0% of the length Lb.

5 . The tire according to claim 4 , wherein
the difference (Lb−La) is in a range from −4.0% to 0.0% of the length Lb.

6 . The tire according to claim 1 , wherein
the length of the band cord piece is at least ¼ of the circumference of the band.

7 . The tire according to claim 1 , wherein
the band is provided so as to extend in the tire axial direction across the tire equator, and a value (Lb−La)/Lb obtained in a crown portion of the band which is defined as being centered on the tire equator and having a developed width of 10% of the developed width of the band is larger than a value (Lb−La)/Lb obtained in a portion of the band other than the crown portion.

8 . The tire according to claim 3 , wherein
the band is provided so as to extend in the tire axial direction across the tire equator, and a value (Lb−La)/Lb obtained in a crown portion of the band which is defined as being centered on the tire equator and having a developed width of 10% of the developed width of the band is larger than a value (Lb−La)/Lb obtained in a portion of the band other than the crown portion.

9 . The tire according to claim 7 , wherein
when a shoulder portion of the band is defined as having a developed width of 10% of the developed width of the band and extending from each of axial edges of the band, and a middle portion of the band is defined as extending between the crown portion and each shoulder portion, then absolute values of differences in the value {(Lb−La)/Lb}×100 between the crown portion, the shoulder portions and the middle portions are not more than 2.0.

10 . The tire according to claim 8 , wherein
when a shoulder portion of the band is defined as having a developed width of 10% of the developed width of the band and extending from each of axial edges of the band, and a middle portion of the band is defined as extending between the crown portion and each shoulder portion, then absolute values of differences in the value {(Lb−La)/Lb}×100 between the crown portion, the shoulder portions and the middle portions are not more than 2.0.

11 . The tire according to claim 1 , wherein
a product (k×N) of a compressive stiffness k of each band cord and an average cord count N per 25 mm of the band is in a range from 1500 to 15000 N/mm.

12 . The tire according to claim 11 , wherein
the average cord count N per 25 mm is 10 to 40.

13 . The tire according to claim 8 , wherein
the developed width of the band is in a range from 70% to 90% of the developed width of the tread portion.

14 . The tire according to claim 18 , wherein
said at least one band cord is a plurality of the band cords, and the band is formed by winding a tape of rubber in which the plurality of the band cords are embedded parallel with each other along the length of the tape.

15 . The tire according to claim 14 , wherein
the band cords include a steel cord.

16 . The tire according to claim 15 , wherein
a compressive stiffness k of each of the band cords is 10 to 1000 N/mm.

17 . The tire according to claim 1 , wherein
each band cord is composed of a plurality of strands twisted together, and the strands include at least one strand shaped before twisted.

18 . The tire according to claim 16 , wherein
each band cord is composed of a plurality of strands twisted together, and the strands include at least one strand shaped before twisted.

19 . The tire according to claim 1 , which is a motorcycle tire.

20 . The tire according to claim 19 , wherein
the tread portion is convexly curved so that the maximum cross section width of the tire lies between tread edges.

Assignees

• Sumitomo Rubber Ind

Inventors

• Shibamoto Shohei

Classifications

• B60C11/00 Primary

  Tyre tread bands; Tread patterns; Anti-skid inserts · CPC title

• B60C2011/0091

  built-up by narrow strip winding · CPC title

• B60C2009/2209

  characterised by tension of the cord during winding · CPC title

• B60C2009/2266

  Density of the cords in width direction · CPC title

• B60C2009/2083

  Density in width direction · CPC title