Patent ID: 6164354
Filing Date: 2000-12-26
Classification: B60C

Abstract:
A pneumatic tire comprisinga tread portion defining a tread having axial edges,at least one circumferential groove disposed in an axial center region of the tread portion,circumferentially spaced main grooves disposed on both sides of the tire equator,the main grooves extending axially outwardly beyond the tread edges, while inclining to one direction and increasing the inclination angle of the main groove center line with respect to the circumferential direction such thatan inclination angle .alpha.1 at an axially inner end of the main groove is 0 to 15 degrees, andan inclination angle .alpha.2 at the tread edge is 60 to 90 degrees,auxiliary grooves each disposed between the circumferentially adjacent main grooves and extending from a middle portion of one of said main grooves towards said one direction and extending beyond the tread edge so as to form a junction of the auxiliary groove with the main groove at an axially inner end of the auxiliary groove at said middle portion,each said main groove having a single branch which is one of said auxiliary grooves and not communicating with said at least one circumferential groove,the width of each said main groove gradually increasing from the inner end thereof and also from the tread edge so as to form a widened part in said middle portion,at each said junction, said auxiliary grooves being narrower in width than said main grooves, and the width of each said auxiliary groove gradually decreasing towards the axially inner end.