Tyre for vehicle wheels

Abstract

Tyre for vehicle wheels, comprising a tread band having a plurality of blocks, at least some of said blocks comprising at least one sipe () extending from an axially outer portion of the block up to an axially inner portion of the block along a predetermined trajectory and from a radially outer face of the block towards a radially inner portion of the block. The sipe () comprises, in any cross-section perpendicular to said predetermined trajectory, a main portion () having a first radial dimension and a first transversal dimension and, in a radially inner position with respect to the main portion () and adjacent to the radially inner portion of the block, a bottom portion () having a second radial dimension smaller than the first radial dimension and a second transversal dimension greater than the first transversal dimension. The second transversal dimension measured in a first cross-section of the sipe () taken at at least one of said axially outer portion of the block and said axially inner portion of the block is greater than the second transversal dimension measured in a second cross-section of the sipe () taken at a portion of the block axially arranged between said axially outer portion of the block and said axially inner portion of the block. The sipe () comprises an axially outer portion (), an axially inner portion () and a central portion () defined between said axially outer portion () and said axially inner portion (). The sipe () comprises, in said central portion (), at least one area in which said predetermined trajectory is not rectilinear.