Tyre for vehicle wheels having improved tread pattern

Abstract

A tyre for vehicle wheels having a tread pattern includes: a) two circumferential grooves, which define a first and a second shoulder region, and one central region; b) a plurality of asymmetric transverse grooves having a substantially “V” shape, which extend for the whole width of the tread, including an alternate sequence of a first and a second asymmetric transverse groove defining an alternate sequence of a first and a second asymmetric module; and c) a plurality of lateral transverse grooves, which includes one first lateral transverse groove extending for the whole width of the first shoulder region and for a portion of the central region of the first asymmetric modules, and one second lateral transverse groove extending for the whole width of the second shoulder region and for a portion of the central region of the second asymmetric modules.

Description

FIELD OF THE INVENTION[0001]The present invention relates to a tyre for vehicle wheels having an improved tread pattern, more in particular to a winter tyre especially suitable for driving on snow and ice, and having good driving performance on wet and dry road.BACKGROUND OF THE ART[0002]A winter tyre is supposed to ensure good traction when used on snow and ice. However, a winter tyre also needs to provide good driving characteristics when used on dry or wet roads.[0003]Winter or snow tyres have been designed with treads having traction blocks widely spaced by large and deep grooves that allow a good traction and brake on snow. The presence of large and deep traction grooves increases the void-to-rubber ratio of the tread, also simply named void ratio i.e., the amount of open space compared to the amount of rubber in the tread. A low void ratio means more rubber in contact with the road and vice versa. The high void ratio tread pattern is excellent in deep snow because snow is trap...

AI Technical Summary

Benefits of technology

[0016]The Applicant has found that the above described tread pattern according to the invention allows to reduce the flexibility of the tread elements and the rolling noise, so improving the performance on dry roads, to provide a good drainage of water and a good grip on wet roads, and to have at the same time an effective grip on snow and ice.

[0019]The Applicant has found that the implementation of the above mentioned preferred embodiment can improve the water drainage when driving on soaked road and can improve the directionality and reduce the wear.

[0023]The Applicant has found that the implementation of the above mentioned preferred embodiment can further improve the effectiveness of the sipes in the traction and the grip on snow and / or ice. On the other hand, a lower number of sipes can be formed to obtain the same traction and grip of the tread on snow and / or ice. Consequently, the stiffness of the tread elements is increased so giving better performances in terms of rolling noise, driving stability and tread wear when driving on dry road.

Problems solved by technology

However, these tread patterns reduce the stiffness of the tread and generate substantial noise and block mobility when used on wet or dry roads.

Moreover, the tread wear rate is rapid and therefore these tyres are considered for use only during the snowy winter months.

Additionally, these tyres are not particularly well suited for icy road conditions.

However, an increased number of sipes again promotes a reduction of the stiffness of the tread with an increase of block mobility and noise during use.

However, broad longitudinal grooves reduce the traction on snow and broad transverse grooves reduce the stiffness of the tread, again increasing the noise and block mobility when driving on dry road.

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