Pneumatic tire

Abstract

A pneumatic tire with a pair of sidewall portions, which comprises at least one of said sidewall portions with a radially outer region being radially outside than a tire maximum width position of its outer surface, the radially outer region being provided with a serration pattern, the serration pattern comprising a first serration group and a second serration group, the first serration group comprising a plurality of concentrically arranged first arc-shaped ridges at regular intervals around a first center point O 1, the second serration group comprising a plurality of concentrically arranged second arc-shaped ridges at regular intervals around a second center point O 2 that is located radially outside than the first center point O 1 of the first serration group, and the first serration group and second serration group arranged in a circumferential direction of the tire so as to overlap partially.

1 . A pneumatic tire having a pair of sidewall portions, which comprises
 at least one of said sidewall portions having a radially outer region being radially outside than a tire maximum width position of its outer surface, the radially outer region being provided with a serration pattern,   said serration pattern comprising a first serration group and a second serration group,   said first serration group comprising a plurality of concentrically arranged first arc-shaped ridges at regular intervals around a first center point O 1 ,   said second serration group comprising a plurality of concentrically arranged second arc-shaped ridges at regular intervals around a second center point O 2  that is located radially outside than the first center point O 1  of said first serration group, and   said first serration group and said second serration group arranged in a circumferential direction of the tire so as to overlap partially.   
     
     
         2 . The tire according to  claim 1 , wherein
 said first arc-shaped ridges and said second arc-shaped ridges have the same cross sections.   
     
     
         3 . The tire according to  claim 2 , wherein
 said first arc-shaped ridges and said second arc-shaped ridges have the same intervals.   
     
     
         4 . The tire according to  claim 1 , wherein
 said first serration group comprises a radially innermost first arc-shaped ridge having a radius of curvature in a range of from 0.5 to 10.0 mm, and   said second serration group comprises a radially innermost second arc-shaped ridge having a radius of curvature in a range of from 0.5 to 10.0 mm.   
     
     
         5 . The tire according to  claim 4 , wherein
 said first arc-shaped ridges and said second arc-shaped ridges have intervals P in a range of from 1.0 to 2.0 mm,   said first arc-shaped ridges and said second arc-shaped ridges have cross sectional widths w in a range of from 0.1 to 0.6 mm,   said first arc-shaped ridges and said second arc-shaped ridges have cross sectional heights H in a range of from 0.2 to 0.6 mm, and   a circumferential length L between the first center point O 1  and the second center point O 2  is in a range of from 20 to 60 mm.   
     
     
         6 . The tire according to  claim 1 , wherein
 said first arc-shaped ridges protrude radially outwardly of the tire, and   said second arc-shaped ridges protrude radially inwardly of the tire.   
     
     
         7 . The tire according to  claim 6 , wherein
 said serration pattern has a radially outer periphery edge and a radially inner periphery edge,   said first center point O 1  is provided in the vicinity of the radially inner periphery edge of said serration pattern, and   said second center point O 2  is provided in the vicinity of the radially outer periphery edge of said serration pattern.