Pneumatic tire and method of manufacturing same

Patent metadata

Field	Value
Publication number	US-11110756-B2
Application number	US-201715597490-A
Country	US
Kind code	B2
Filing date	May 17, 2017
Priority date	May 19, 2016
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

A pneumatic tire is provided in the tread portion with a land portion including a conductive portion made of a conductive rubber. The conductive portion has a radially inner end electrically connected to a conductive tire internal structural to be connected to a wheel rim, and a radially outer end exposed in a ground contacting top surface of the land portion. The conductive portion extends from its radially inner end to outer end while inclining toward a first side surface of the land portion. The first side surface comprises a radially inner part, and a radially outer part extending radially outwardly from the radially inner part while inclining to the radially outer end of the conductive portion at an angle greater than the radially inner part.

First claim

The invention claimed is:

1. A pneumatic tire comprising:
a tread portion provided with a land portion having a top surface for contacting with the ground,
the land portion having a first side surface extending radially inwardly from a first axial edge of the top surface, and a second side surface extending radially inwardly from a second axial edge of the top surface,
the land portion provided with a conductive portion made of a conductive rubber,
the conductive portion having a radially outer end exposed in said top surface, and a radially inner end electrically connected to a conductive internal structure of the tire which is to be electrically connected to a wheel rim when the tire is mounted on the wheel rim,
wherein
in a cross section of the land portion taken along a plane including the rotational axis of the tire,
the conductive portion inclines to the first side surface of the land portion toward the radially outer end from the radially inner end of the conductive portion, so that the radially outer end of the conductive portion is closer to the first axial edge than the second axial edge,
the first side surface comprises a radially inner part and a radially outer part extending from the radially inner part to the first axial edge while inclining to the conductive portion at an inclination angle being larger than an inclination angle of the radially inner part,
the land portion is a circumferentially continuous rib,
a top surface of the land portion is provided with:
first center lug grooves extending from the first axial edge toward the conductive portion and terminating without intersecting the conductive portion in the top surface of the land portion, and
second center lug grooves extending from the second axial edge toward the conductive portion and terminating without intersecting the conductive portion in the top surface of the land portion,

the first center lug grooves and the second center lug grooves are inclined in the same direction with respect to the tire axial direction, and
the first center lug grooves have a length, and the second center lug grooves have a length greater than the length of the first center lug grooves.

2. The pneumatic tire according to claim 1 , wherein in said cross section of the land portion, the angle between the conductive portion and said top surface is not less than 40 degrees and not more than 90 degrees.

3. The pneumatic tire according to claim 1 , wherein the distance from the first axial edge to the radially outer end of the conductive portion is at least 1.5 mm.

4. The pneumatic tire according to claim 1 , wherein in said cross section of the land portion, an area surrounded by said radially outer part, an axially extended line of said top surface and a radially outwardly extended line of said radially inner part is in a range from 1.0% to 2.5% of an overall area of the land portion.

5. The pneumatic tire according to claim 1 , wherein in said cross section of the land portion, a radial height of said radially outer part of the first side surface is in a range from 30% to 60% of the radial height of the land portion.

6. The pneumatic tire according to claim 4 , wherein the distance from the first axial edge to the radially outer end of the conductive portion is at least 1.5 mm.

7. The pneumatic tire according to claim 5 , wherein the distance from the first axial edge to the radially outer end of the conductive portion is at least 1.5 mm.

8. The pneumatic tire according to claim 1 , wherein
the second center lug grooves extend while curving toward one direction and inclining with respect to the tire axial direction.

9. The pneumatic tire according to claim 8 , wherein
the first center lug grooves extend straight.

10. The pneumatic tire according to claim 9 , wherein
the first center lug grooves are respectively connected to chamfered portions intermittently formed on the first axial edge by the radially outer part of the first side surface.

11. The pneumatic tire according to claim 10 , wherein
the chamfered portions have a substantially constant axial width W 1 along their respective entire lengths in the tire circumferential direction, and
the axial width W 1 is in a range from 1.5 mm to 2.5 mm.

12. The pneumatic tire according to claim 11 , wherein
the distance between the chamfered portions and the radially outer end of the conductive portion is in a range from 1.5 to 2.5 mm at the top surface of the land portion.

13. The pneumatic tire according to claim 12 , wherein in said cross section of the land portion, the angle between the conductive portion and said top surface is not less than 40 degrees and not more than 90 degrees.

14. The pneumatic tire according to claim 12 , wherein
the chamfered portions have a radial height in a range from 30% to 60% of the overall height of the land portion.

15. A pneumatic tire comprising:
a tread portion provided with a land portion having a top surface for contacting with the ground,
the land portion having a first side surface extending radially inwardly from a first axial edge of the top surface, and a second side surface extending radially inwardly from a second axial edge of the top surface,
the land portion provided with a conductive portion made of a conductive rubber,
the conductive portion having a radially outer end exposed in said top surface, and a radially inner end electrically connected to a conductive internal structure of the tire which is to be electrically connected to a wheel rim when the tire is mounted on the wheel rim,
wherein
in a cross section of the land portion taken along a plane including the rotational axis of the tire,
the conductive portion inclines to the first side surface of the land portion toward the radially outer end from the radially inner end of the conductive portion, so that the radially outer end of the conductive portion is closer to the first axial edge than the second axial edge, and
the angle between the conductive portion and said top surface is not less than 40 degrees and not more than 90 degrees,

wherein
the first side surface comprises a radially inner part and a radially outer part extending from the radially inner part to the first axial edge while inclining to the conductive portion at an inclination angle being larger than an inclination angle of the radially inner part,
in said cross section of the land portion, a radial height of said radially outer part of the first side surface is in a range from 30% to 60% of the radial height of the land portion, and
in said cross section of the land portion, an area surrounded by said radially outer part, an axially extended line of said top surface and a radially outwardly extended line of said radially inner part is in a range from 1.0% to 2.5% of an overall area of the land portion,

wherein
said top surface of the land portion is provided with:
first center lug grooves extending from the first axial edge toward the conductive portion and terminating without intersecting the conductive portion in the top surface of the land portion, and
second center lug grooves extending from the second axial edge toward the conductive portion and terminating without intersecting the conductive portion in the top surface of the land portion, whereby the land portion is formed as a circumferentially continuous rib,

wherein
the first center lug grooves and the second center lug grooves are arranged alternately in the tire circumferential direction,
the first center lug grooves and the second center lug grooves are inclined in the same direction with respect to the

Assignees

• Sumitomo Rubber Ind

Inventors

• Mukai Yu
• Kanematsu Yoshiaki

Classifications

• B60C19/082 Primary

  comprising a conductive tread insert · CPC title

• B29D30/0606

  Vulcanising moulds not integral with vulcanising presses (for solid tyres B29D30/02) · CPC title

• B29K2995/0005

  Conductive · CPC title

• B29D30/0601

  Vulcanising tyres; Vulcanising presses for tyres · CPC title

• B60C11/0304

  Asymmetric patterns · CPC title