Pneumatic tire

Patent metadata

Field	Value
Publication number	US-10894444-B2
Application number	US-201815868059-A
Country	US
Kind code	B2
Filing date	Jan 11, 2018
Priority date	Jan 24, 2017
Publication date	Jan 19, 2021
Grant date	Jan 19, 2021

Abstract

In a tire 2 , a band 14 has a helically wound structure in which a strip 26 having a cord 28 is wound in a circumferential direction. The band 14 includes a center portion C disposed at a center in an axial direction, and a shoulder portion S disposed outward of the center portion C in the axial direction. A pitch Pc of the strip 26 in the center portion C is not less than 2.0 times a width W of the strip 26 and not greater than 2.5 times the width W. A pitch Ps of the strip 26 in the shoulder portion S is not less than 0.8 times the width W of the strip 26 and not greater than 1.2 times the width W.

First claim

What is claimed is:

1. A pneumatic tire comprising:
a tread that forms a tread surface which comes into contact with a road surface; and
a band disposed inward of the tread in a radial direction, wherein
the band has a helically wound structure in which a strip having a cord is wound in a circumferential direction,
the band includes a center portion disposed at a center in an axial direction, and a shoulder portion disposed outward of the center portion in the axial direction,
a pitch Pc of the strip in the center portion is not less than 2.0 times a width W of the strip and not greater than 2.5 times the width W,
a pitch Ps of the strip in the shoulder portion is not less than 0.8 times the width W of the strip and not greater than 1.2 times the width W,
on a cross-section perpendicular to the circumferential direction, a profile of the tread surface has a first arc C 1 that intersects an equator plane, and a second arc C 2 that contacts with the first arc C 1 ,
a ratio (R 1 /R 2 ) of a curvature radius R 1 of the first arc C 1 to a curvature radius R 2 of the second arc C 2 is not less than 210% and not greater than 250%, and
when A represents a contact point at which the first arc C 1 and the second arc C 2 contact with each other, and
the contact point A is disposed outward of a boundary of the center portion and the shoulder portion in an axial direction.

2. The tire according to claim 1 , wherein
the band is a full band formed from one layer.

3. The tire according to claim 1 , wherein
the ratio (R 1 /R 2 ) is not greater than 220%.

4. The tire according to claim 1 , wherein
a ratio (Wa/Wt) of a distance Wa from the equator plane to the contact point A in the axial direction, relative to a width Wt of the tread in the axial direction is not less than 30% and not greater than 40%.

5. The tire according to claim 1 , wherein
the strip includes a steel cord.

6. A pneumatic tire comprising:
a tread that forms a tread surface which comes into contact with a road surface; and
a band disposed inward of the tread in a radial direction; and
a belt disposed inward of the band in a radial direction, wherein
the band has a helically wound structure in which a strip having a cord is wound in a circumferential direction,
the band includes a center portion disposed at a center in an axial direction, and a shoulder portion disposed outward of the center portion in the axial direction,
a pitch Pc of the strip in the center portion is not less than 2.1 times a width W of the strip and not greater than 2.3 times the width W,
a pitch Ps of the strip in the shoulder portion is not less than 0.8 times the width W of the strip and not greater than 1.2 times the width W,
an outer end of the band is disposed outward of a corresponding outer end of the belt in an axial direction,
the band is a full band formed from one layer,
on a cross-section perpendicular to the circumferential direction, a profile of the tread surface has a first arc C 1 that intersects an equator plane, and a second arc C 2 that contacts with the first arc C 1 ,
a ratio (R 1 /R 2 ) of a curvature radius R 1 of the first arc C 1 to a curvature radius R 2 of the second arc C 2 is not less than 210% and not greater than 220%,
the tread has grooves formed therein,
when A represents a contact point at which the first arc C 1 and the second arc C 2 contact with each other, the contact point A is disposed outward of a boundary of the center portion and the shoulder portion in an axial direction;
a width Ls of the shoulder portion is not less than 16% of a width Lb of the band and not greater than 30% of the width Lb, in the axial direction;
the pitch Pc of the strip in the center portion is uniform; and
a ratio (Wa/Wt) of a distance Wa from the equator plane to the contact point A in the axial direction, relative to a width Wt of the tread in the axial direction is not less than 30% and not greater than 40%.

7. The tire according to claim 6 , wherein
the strip includes a steel cord.

Assignees

• Sumitomo Rubber Ind

Inventors

• Mukai Yu

Classifications

• B60C2009/2271

  with variable density · CPC title

• B60C2009/2035

  built-up by narrow strips · CPC title

• B60C2009/2016

  comprising cords at an angle of 10 to 30 degrees to the circumferential direction · CPC title

• B60C11/01

  Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered · CPC title

• B29D30/70

  Annular breakers · CPC title