The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 23, 2000
Filed:
Jan. 09, 1998
Hirokatsu Maruyama, Hiratsuka, JP;
The Yokohama Rubber Co., Ltd., Tokyo, JP;
Abstract
A heavy duty pneumatic radial tire having sub grooves provided on a tread surface which has a center main groove and two outer main grooves. The sub grooves extend in the tire width direction and together with the main grooves, divisionally form two block rows composed of a plurality of blocks. The sub grooves are inclined in a direction opposite to the tire rotating direction from the center main groove toward the outer main grooves. The inclination angle of the sub grooves is gradually and continuously reduced from a first inclination angle measured at the center main groove to a second inclination angle measured at the outer main groove. The first inclination angle is set in the range from 70 to 90.degree. while the second inclination angle is set in the range of greater than 30.degree. and less than the first inclination angle. Further, notched grooves can be provided dividing the shoulder areas of the tread surface into a plurality of blocks. The notched grooves can be inclined in a direction opposite to the tire rotating direction.