| US 7,516,767 B2 | ||
| Pneumatic tire with tread having zigzag sipes | ||
| Fumihiro Tsubono, Kobe (Japan); Mitsuharu Koya, Kobe (Japan); and Naoki Kageyama, Kobe (Japan) | ||
| Assigned to Sumitomo Rubber Industries, Ltd., Kobe-shi (Japan) | ||
| Filed on Nov. 23, 2005, as Appl. No. 11/284,848. | ||
| Claims priority of application No. 2004-355324 (JP), filed on Dec. 08, 2004. | ||
| Prior Publication US 2006/0118221 A1, Jun. 08, 2006 | ||
| Int. Cl. B60C 11/12 (2006.01) | ||
| U.S. Cl. 152—209.21 [152/209.23; 152/902; 425/28.1; 425/46] | 10 Claims |
| 1. A pneumatic tire comprising
a tread portion provided with sipes,
the sipes each having a zigzag configuration at any depth from the top of the sipe to a certain depth,
the zigzag configuration having vertexes Q1 on one side of the zigzag and vertexes Q2 on the other side of the zigzag defining a center line with respect to the peak-to-peak zigzag amplitude of the zigzag configuration,
wherein
as the depth increases from the top of the sine to said certain depth,
the vertexes Q1 shift in the longitudinal direction of the sipe and the direction of the shift is turned at least once such that the vertexes
Q1 first shift towards one direction then towards the other direction, thereby describing a zigzag line extending from the top
of the sipe to said certain depth and having at least one turning point, and
the vertexes Q2 do not shift in the longitudinal direction, whereby each vertex Q2 describes a straight line extending from the top of the sipe to said certain depth,
said center line defines a center plane, wherein
the vertexes Q1 are on a plane on one side of the center plane and parallel to the center plane, and
the vertexes Q2 are on a plane on the other side of the center plane and parallel to the center plane.
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