PNEUMATIC TIRE Russian patent published in 2012 - IPC B60C11/11 B60C11/03 

FIELD: transport.

SUBSTANCE: invention relates to automotive tire with tread for winter operating conditions. Set of G_B blocks is arranged on, at least, part of tire tread 1 with blocks 3 located nearby each other. Said blocks are formed by grooves 2 and separated one from another. Symbol P (mm) designates characteristic spacing of blocks in said group G_B. Symbol W (mm) designated width of set of blocks. Symbol a (pcs) designates quantity of blocks 3 in design area Z of aforesaid group G_B. Design area is demarcated by characteristic length of spacing P and width W while symbol N (%) designates negative factor in area Z. Density S of blocks per unit of actual area of contact spot of said group is defined by the formula S=a/{P×W×(1-N/100)} and set in the range of at least 0.003 (pc./mm²) to not over 0.04 (pc./mm²).

EFFECT: higher efficiency on ice.

6 cl, 18 dwg, 4 tbl