Patent ID: 9174492
Filing Date: 2015-11-03
Classification: B60C

Abstract:
1. A pneumatic tire comprises a tread portion provided with a tread pattern asymmetric about the tire equator and having an inboard tread edge and an outboard tread edge to be positioned inside and outside, respectively, of a vehicle, wherein said tread portion provided with circumferentially-continuously-extending longitudinal grooves each being a straight groove having a width W an inboard shoulder land region of the tread portion, which is defined between the inboard shoulder longitudinal groove and the inboard tread edge, is provided with inboard shoulder transverse grooves extending at an angle of from 75 to 90 degrees with respect to the tire circumferential direction from outside of the inboard tread edge toward the inboard shoulder longitudinal groove but terminating without reaching thereto, an outboard shoulder land region of the tread portion, which is defined between the outboard shoulder longitudinal groove and the outboard tread edge, is provided with outboard shoulder transverse grooves extending at an angle of from 80 to 90 degrees with respect to the tire circumferential direction from the outboard shoulder longitudinal groove toward the outboard tread edge and terminating at a position beyond the outboard tread edge, an inboard middle land region of the tread portion, which is defined between the inboard central longitudinal groove and the inboard shoulder longitudinal groove, is provided with inboard middle transverse grooves extending at an angle of from 25 to 50 degrees with respect to the tire circumferential direction, wherein the inboard middle transverse grooves include: first inboard middle transverse grooves each having an inboard end opened to the inboard shoulder longitudinal groove, and an outboard end opened to the inboard central longitudinal groove; and second inboard middle transverse grooves having an inboard end opened to the inboard shoulder longitudinal groove and an outboard end terminated without reaching to the inboard central longitudinal groove, an outboard middle land region of the tread portion, which is defined between the outboard center longitudinal groove and the outboard shoulder longitudinal groove, is provided with outboard middle transverse grooves extending from the outboard shoulder longitudinal groove to the outboard center longitudinal groove, while inclining to one circumferential direction, to have an outboard end opened to the outboard shoulder longitudinal groove and an inboard end opened to the outboard center longitudinal groove, said inboard shoulder land region is provided with inboard shoulder narrow grooves each extending from one of the outboard ends of the inboard shoulder transverse grooves to the circumferentially adjacent inboard shoulder transverse groove, while inclining toward the inboard tread edge, a crown region defined between an inboard edge of the inboard shoulder longitudinal groove and an outboard edge of the outboard shoulder longitudinal groove has a sea ratio in a range of from 30 to 50%, and a central land region defined between the inboard central longitudinal groove and the outboard center longitudinal groove is provided with central transverse grooves each being an independent groove having an outboard end opened to the outboard center longitudinal groove and an inboard closed end, said central transverse grooves being narrower central transverse grooves and wider central transverse grooves arranged alternately in the tire circumferential direction, and the narrower central transverse grooves extend across the tire equator whereas the wider central transverse grooves end without reaching to the tire equator.