PNEUMATIC TIRE Russian patent published in 2008 - IPC B60C11/12 

FIELD: transport.

SUBSTANCE: invention relates to automotive tires. The tread body is furnished with a dropper running axially in a zigzag manner and deep into the tire, the said dropper having an invariable depth. It features the rigidity index F defined as shown below, varying in the dropper lengthwise direction. The rigidity index makes F=(1+φ1)x(1+φ2)x(1+φ3), where φ1 is the dropper amplitude (mm) on the tire body step; φ2 is the dropper amplitude (mm) across the body section perpendicular to the dropper line on the step surface; φ3 is the dropper ridge line amplitude, the ridge running deep down, if the dropper wall surface seen from above. More particularly, the dropper amplitude φ1 on the tire outside exceeds, in axial direction, the dropper amplitude φ1' on the tire equatorial plane, and the dropper amplitude φ2 on the tire outside exceeds, in axial direction, the dropper amplitude φ2' on the tire equatorial plane. Thus, an irregular tire tread wear property is combined with adequate operating properties on moistened and snow-covered road surfaces.

EFFECT: reliable steering on moistened and snow-covered road surfaces.

9 cl, 22 dwg, 2 tbl