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:
Oct. 03, 2000
Filed:
Feb. 13, 1998
Ken Takahashi, Hiratsuka, JP;
Norio Ohmoto, Hiratsuka, JP;
The Yokohama Rubber Co., Ltd., Tokyo, JP;
Abstract
In a heavy duty pneumatic radial tire, at least one carcass layer is provided between right and left bead portions and at least two belt layers formed of steel cords which exhibit a breaking elongation of 4% or less are arranged in an outer periphery of the carcass layer in a tread portion. The belt layers are composed of at least one upper belt layer (A) and at least one lower belt layer (B). The upper belt layer (A) has a belt width that is 0.6 times or less a carcass line maximum width SW of the carcass layer at a tire section and the lower belt layer (B) has a belt width such that both end portions thereof extend to tread shoulder portions. An inclination angle of the steel cords of the lower belt layer (B) relative to a tire circumferential direction is set to be larger than that of the upper belt layer (A). A ratio (Mb.sub.2 .multidot.N.sub.2)/( Mb.sub.1 .multidot.N.sub.1) of a product of a bending rigidity Mb.sub.2 per steel cord of the lower belt layer (B) and the number N.sub.2 of the steel cords per unit width of the lower belt layer (B) to a product of a bending rigidity Mb.sub.1 per steel cord of the upper belt layer (A) and the number N.sub.1 of the steel cords per unit width of the upper belt layer (A) is set to be at a range of 0.2 to 0.65.