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:
Jul. 29, 1980
Filed:
Apr. 14, 1978
Hiroyoshi Takigawa, Kodaira, JP;
Hiroshi Ogawa, Kodaira, JP;
Shinichiro Ohkuni, Kodaira, JP;
Mitsuhisa Yahagi, Sayama, JP;
Bridgestone Tire Company Limited, Kyobashi, JP;
Abstract
A heavy duty pneumatic radial tire comprises a tread continuous at its round-shaped shoulders with sidewalls and formed with a plurality of main tread grooves extending circumferentially thereof. The tread is formed with a circumferentially extending narrow groove in zigzag in each end zone of contact surfaces of the shoulders with a road surface under a standard load. The zigzag grooves have a width of 15-30% of that of the main tread grooves, an amplitude of 0.5-2.0% of the tread width and a pitch of 2.0-7.0% of the tread width. Each of the shoulders is formed in its side surface with a series of intermittent circumferential caved portions, such that a distance in an axial direction of the tire between the deepest bottoms of the caved portions is 105-110% of the tread width and the deepest bottoms are located in a circle having a diameter less than that of a circle passing through the bottoms of the main tread grooves. With the arrangement, the tire according to the invention does not cause any irregular wear at the shoulders and can reduce and prevent the railway wear and growth thereof toward the center of the tread, so that the wear-resistance of the tire is remarkably improved.