Bridgestone Tire Company Limited

Nobuhiro Miyamura

Hiroyoshi Takigawa

Hiroshi Ogawa

Shinichiro Ohkuni

A heavy duty pneumatic tire having a tread provided on its outer surface with a plurality of circumferential grooves is disclosed. At least one of the circumferential grooves is opened on the tread surface at an open groove width corresponding to 2-8% of tread transverse width, has a groove bottom width substantially equal to the open groove width, and is provided on its groove bottom with plural protrusions separated from the opposed groove walls and at an interval between the adjoining protrusions in the circumferential direction of the groove.

Tread with spaced projections in stone ejecting groove

A heavy duty pneumatic tire includes a tread in a crown of a tire body reinforced by a toroidal carcass extending between a pair of annular bead cores. The tread is formed with a pair of main wide grooves circumferentially spaced apart at least one half of a tread width of the tire on both sides of a central circumferential line and a wide subgroove extending along the central circumferential line and in parallel with the main wide grooves to form first ribs bounded by the wide subgroove and the main wide grooves and second ribs bounded by the main grooves and tread edges. Each first rib is formed with a narrow groove extending circumferentially to divide the first rib into two parts. The tire according to the invention is made superior in antiskid characteristic on wet roads by improving the drainage without sacrificing the wear resistance of the tire.

Heavy duty pneumatic tire tread

A pneumatic tire for heavy load vehicles such as trucks and buses comprising a tread composed of a flat main region and an inclined region located at both side edges of the flat main region and including a number of notches spaced apart from each other and arranged substantially transversely to the circumferential direction of the tire.

Pneumatic tire for heavy load vehicles

A radial tire for heavy load vehicles comprising a tread portion having an outer contour composed of a relatively transversely flat main region and a conical region located at both end edges of the main region. A number of thin incisions extend across the conical region having inner ends not reaching to the inside of the main region.

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Higashimurayama, Japan

Nobuhiro Miyamura