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. 28, 1986
Filed:
Nov. 29, 1984
Seiichiro Tokunaga, Higashimurayama, JP;
Nobumasa Ikeda, Kodaira, JP;
Bridgestone Corporation, , JP;
Abstract
Disclosed herein is a pneumatic tire having a tread pattern formed in a tread portion divided into separate blocks at an outer surface of a tread rubber layer in at least a central region of said tread portion by a plurality of main grooves extending circumferentially and a great number of lateral grooves each extending toward a cross direction to each of said main grooves and having a shallower portion as compared with said main groove. The tread portion is a cap-base composite tread portion composed of an upper rubber layer forming a pattern of blocks and a lower rubber layer bordered on said upper rubber layer just therebeneath by a face connecting groove bottoms of said shallower portions of lateral grooves and forming a pattern of ribs separated from one another by said main grooves in the lateral direction and extending substantially continuously in the circumferential direction, and said upper rubber layer is substantially composed of a cap rubber having a JIS hardness at -20.degree. C. of not more than 75.degree. and said lower rubber layer is substantially composed of a base rubber having a JIS hardness at 100.degree. C. of not less than 54.degree. and a loss tangent of not more than 0.22 at 50 Hz, 25.degree. C. and a strain of 2%.