Title:
RUN-FLAT TIRE
Document Type and Number:
WIPO Patent Application WO/2022/208971
Kind Code:
A1
Abstract:
A run-flat tire according to the present invention comprises a tread part, a sidewall part, a bead part, a side reinforcement rubber having a crescent cross-section, and a carcass. A portion of the side reinforcement rubber is composed of a low-elasticity portion having a lower elastic modulus than the remaining portion of the tire. In a reference condition, the low-elasticity portion is located in a tire radial-direction region that falls within a range of 50-80% of the tire cross-section height from a bead base line. The elastic modulus of the low-elasticity portion is not more than 80% of the elastic modulus of the remaining portion of the tire. In the tire width-direction cross-section in the reference condition, a ratio t1/t2 of 0.2-3.0 is satisfied, where t1 represents the maximum thickness of the low-elasticity portion measured in the direction of a perpendicular line extending from the carcass to the inner surface of the tire, and t2 represents the thickness of the remaining portion measured in the direction of the perpendicular line. The maximum width of the tire in the reference condition falls between a center value and an upper limit value of the tire maximum width as defined by a specification, and the position of the tire maximum width in the reference condition is closer to the tire radial-direction outer side than a position which is distanced, by 50% of the tire cross-section height, from the bead base line toward the tire radial-direction outer side.
Inventors:
SAKIYAMA TOMOTAKA (JP)
IWATANI TAKESHI (JP)
IWATANI TAKESHI (JP)
Application Number:
PCT/JP2021/040884
Publication Date:
October 06, 2022
Filing Date:
November 05, 2021
Export Citation:
Assignee:
BRIDGESTONE CORP (JP)
International Classes:
B60C17/00; B60C5/14
Foreign References:
| JP2008155672A | 2008-07-10 | |||
| JP2013199155A | 2013-10-03 | |||
| JP2009126410A | 2009-06-11 | |||
| JP2000108618A | 2000-04-18 | |||
| JP2004074914A | 2004-03-11 | |||
| JP2013071672A | 2013-04-22 | |||
| JP2015016765A | 2015-01-29 | |||
| JPS62279107A | 1987-12-04 | |||
| JP2007505783A | 2007-03-15 | |||
| JP2015214306A | 2015-12-03 | |||
| JPH01278806A | 1989-11-09 | |||
| JP2001138721A | 2001-05-22 | |||
| KR102070917B1 | 2020-01-29 | |||
| DE102018215196A1 | 2020-03-12 |
Other References:
"STANDARDS MANUAL of ETRTO", 2013, THE EUROPEAN TYRE AND RIM TECHNICAL ORGANIZATION, article "FUTURE DEVELOPMENTS"
Attorney, Agent or Firm:
SUGIMURA Kenji (JP)
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