NON-STUDDED SNOW TIRE Russian patent published in 2011 - IPC B60C11/04 B60C11/12 

FIELD: transport.

SUBSTANCE: tread comprises grooves to allow coefficient of efficient/total area of 0.65 to 0.75. Tread grooves comprise axially inner lengthwise groove, axially outer lengthwise groove and multiple recesses on each side of tire crown. Each coefficient of efficient/total area of shoulder and crown exceeds that of mid zone wherein crown width is constricted by central lines of inner lengthwise grooves. Mid zone width is constructed by central line of axially inner lengthwise groove and axially outer lengthwise groove. Shoulder width is constricted by central line of outer lengthwise groove and tread edge.

EFFECT: higher safety on ice- and snow-covered road.

7 cl, 4 dwg, 1 tbl