US 12,011,953 B2
Car tyre
Gianfranco Colombo, Milan (IT); Roberto Bolzoni, Milan (IT); Stefano Bizzi, Milan (IT); and Daniele Lorenzetti, Milan (IT)
Assigned to Pirelli Tyre S.P.A., Milan (IT)
Filed by PIRELLI TYRE S.P.A., Milan (IT)
Filed on Jan. 20, 2021, as Appl. No. 17/153,818.
Application 17/153,818 is a continuation of application No. 14/392,228, granted, now 10,933,696, previously published as PCT/IB2014/001333, filed on Jul. 16, 2014.
Claims priority of application No. RM2013A000422 (IT), filed on Jul. 16, 2013.
Prior Publication US 2021/0138837 A1, May 13, 2021
Int. Cl. B60C 11/03 (2006.01); B60C 11/13 (2006.01)
CPC B60C 11/033 (2013.01) [B60C 11/0304 (2013.01); B60C 11/0306 (2013.01); B60C 11/1392 (2013.01); B60C 11/0318 (2013.01); B60C 2011/0341 (2013.01); B60C 2011/0348 (2013.01); B60C 2011/0353 (2013.01); B60C 2011/0355 (2013.01); B60C 2011/036 (2013.01); B60C 2011/0365 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A car tyre having a tread comprising a central portion located across an equatorial plane, a first shoulder portion located towards an outer side of the tyre and a second shoulder portion located towards an inner side of the tyre, the central portion being separated from said shoulder portions by two first circumferential grooves having a respective minimum width of about 5 mm, wherein:
said first shoulder portion and said second shoulder portion comprise a plurality of first transverse grooves having a first end located substantially at a respective edge of the tread, having a width greater than or equal to about 4 mm and an axial extension equal to at least 50% of the width of the shoulder portion in which they are located;
said two first circumferential grooves are a first circumferential groove facing towards the outer side of the tyre and a first circumferential groove facing towards the inner side of the tyre, the first circumferential groove facing towards the outer side of the tyre having a width smaller than the width of the first circumferential groove facing towards the inner side of the tyre;
the number of said first transverse grooves of the first shoulder portion is lower than the number of said first transverse grooves of the second shoulder portion;
said central portion comprises at least one circumferential rib, comprising a plurality of second transverse grooves;
said second transverse grooves have a maximum width smaller than or equal to about 3 mm and define in said at least one circumferential rib a void-to-rubber ratio smaller than 0.06;
said second transverse grooves comprise a first substantially straight segment extending over at least 50% of the total extension of the second transverse grooves, said first substantially straight segment having an extension smaller than 95% of the total extension of the second transverse grooves; and
said second transverse grooves are spaced between 40 mm and 80 mm from each other in a circumferential direction.