Sumitomo Rubber Industries Limited

Yasuhiro Narahara

Wako Iwamura

Masayuki Sakamoto

Yutaka Kuroda

Yukishige Adachi

Toru Nishikawa

Atsushi Yamakage

Takuji Kusumoto

Yoshiyuki Kawai

A pneumatic tire including a carcass containing a ply of cords defining the innermost reinforcing cord layer extending between bead portions, and an airtight layer disposed inside the cords of the carcass ply along the inner surface of the tire, covering substantially the entire inner surface of the tire, wherein the airtight layer is made of air-impermeable rubber including at least 10 weight % of halogenated butyl rubber and/or halogenated isobutylene-paramethyl styrene copolymer in its rubber base, and the thickness of the airtight layer measured from the inner surface of the tire to the cords of the carcass ply is in a range of from 0.2 to 0.7 mm.

Pneumatic tire with specified airtight layer on inner surface

The invention relates to a pneumatic radial tire that has a tread of straight grooves of broad and narrow widths and which is adapted to insure sufficient rigidity in the tread to provide better steering stability. Tie bars are provided in straight sub-grooves of narrow width one of which is located between an inner middle block and an outer middle block, thereby reinforcing the acute-angled portions of the inner and outer middle blocks. Each tie bar consists of an inner tie bar with length L.sub.1 that extends in contact with the land angle of .alpha..sub.1 of the inner middle block and an outer tie bar with length L.sub.2 that extends in contact with the land angle .alpha..sub.2 of the outer middle block.

Pneumatic radial tire including a tread with tie bars

A radial ply tire with a steel belt, which comprises a carcass ply turned up around bead cores from the axially inside to the outside thereof and a belt comprising two plies of parallel steel cords disposed radially outside the carcass ply in a tread portion of the tire, wherein the amount of steel included in the radially innermost belt ply per an axial unit width and a circumferential unit length there is less than that in the radially outer belt ply disposed on the radially outside of the innermost belt ply.

Radial ply tire

Growing community of inventors

Kobe, Japan

Yasuhiro Narahara