Sumitomo Rubber Industries Limited

Yasuo Wada

Naoki Yukawa

Kazumi Yamazaki

Takashi Tanaka

Makoto Hizume

Kazuo Asano

Hiroshi Ito

Akira Kajikawa

Tetsuya Sakaguchi

Hiroshi Itoh

A flat tire () according to the present invention includes a load support layer () positioned on an inside in an axial direction of a sidewall (). The tire () further includes a belt () constituted by an inner belt ply () and an outer belt ply (), and a full band () substantially covering a whole surface on an outside in a radial direction of the belt (). The full band () is formed by a cord and a topping rubber. When a tensile load of 50N is applied, the cord has an elongation of 3.0% or less. The tire () may include a center band which has a smaller width in the axial direction than the width of the full band () and is laminated on the full band () in the vicinity of an equator (CL).

Run flat tire

Inside a tread portion and outside a belt layer along the radius direction thereof is formed a belt layer comprising a band ply formed by winding spirally a tape- and belt-form ply wherein one ore plural band cords are stretched and arranged to be embedded in a topping rubber. In this band ply, the elongation resistance value K (unit: N' cord number/cm) specified by the following equation is set within the range of 99 to 700 when the sectional area of the band cord or each of the band cords is represented by S (unit: mm), the modulus thereof when the elongation thereof is 2% is represented by M (unit: N/mm), the band cord arrangement density per cm of the band ply is represented by D (unit: cord number/cm).&#x2003;&#x2003;(1)

Pneumatic radial tire

A pneumatic tire comprises a bead core and a rubber bead apex provided in each bead portion, and a carcass comprising a carcass ply turned up around the bead core from the inside to the outside of the tire to form a pair of turned up portions and a main portion therebetween. The bead apex is made of hard rubber disposed between the main portion and turned up portion and extending radially outwards from the bead core. The length (LA) of the bead apex is in a range of from 0.1 to 0.25 times the tire section height (H). A reinforcing cord layer is disposed along the axially inside of the turned up portion. The radially outer end (FU) of the reinforcing cord layer is positioned radially outside the radially outer end (BU) of the bead apex but radially inside the maximum tire section width point (M). The radially inner end (FD) of the reinforcing cord layer is positioned radially outside the radially outer end of the bead core but radially inside the radially outer end (BU) of the bead apex. The length (LB) of the reinforcing cord layer is in a range of from 1.2 to 2.0 times the bead apex length LA. The sidewall portion of the tire has a minimum thickness (Wmin) being in a range of not more than 0.5 times a maximum thickness (Wmax) of a region where the reinforcing cord layer exists.

Pneumatic tire

A vehicle comprises Anti Lock Brake System (ABS) and front tires and rear tires which are capable of displaying maximum braking effect when the ABS is in operation, each of the tires comprises a plurality of tread elements divided by tread grooves, and the tread pattern rigidity Pr of the rear tire is more than the tread pattern rigidity Pf of the front tire, wherein the tread pattern rigidity P (Pr, Pf) is defined as a quotient of the total of circumferential rigidity of all the tread elements existing in a ground contacting region of the tire which is divided by the area of the ground contacting region, and the circumferential rigidity K of each tread element is defined as a quotient of a tangential force F in kgf received at the ground contacting region which is divided by a displacement y in mm at the ground contacting region.

Front and rear tire combination for vehicle having ABS and vehicle

A pneumatic tire comprises a breaker disposed radially outside a carcass crown portion, and a band disposed radially outside of the breaker and comprising a full-width band ply extending over the substantially overall width of the breaker, wherein a cord or cords of said full-width band ply existing in a tread crown region satisfy the following conditions: T>0.8; 0&lE;K&plus;6.67T&minus;21.7; 0&lE;45&minus;10T&minus;K; 0&lE;106.8&minus;57.5T&minus;K; and 7&lE;E&lE;13, wherein the symbol &ldquo;K&rdquo; is an stretch-resistance index (N) of a cord which is defined as the product of the sectional area S in sq.mm and 2% modulus M in N/sq.mm of the cord divided by 100, the symbol &ldquo;T&rdquo; is an stretch in % of the cord in the tire being in its natural state without being mounted on a wheel rim, and the symbol &ldquo;E&rdquo; is a cord count per 1 cm width of the full-width band ply.

Pneumatic tire with specified band cord

A pneumatic tire comprises: a carcass extending between bead portions through a tread portion and sidewall portions; a breaker disposed radially outside a crown portion of the carcass; a pair of axially spaced high modulus edge bands disposed radially outward of edge portions of the breaker and each made of one or more high modulus cords having a sectional area SH and a 2% modulus MH and wound substantially parallel to the tire circumferential direction at a cord count DH; a low modulus middle band disposed radial outward of the breaker between the high modulus edge bands; and an elongation resistance index PH of each of the high modulus edge bands, which is defined as the product of the 2% modulus MH in N/sq.mm, the sectional area SH in sq.mm and the cord count DH per 1 cm width divided by 100, being in a range of 160 to 700.

Pneumatic tire with axially spaced high modulus edge bands and low modulus middle band

The invention provides an apparatus, and a method, for detecting the tread profile of a tire mounted about an X-axis comprising a non-contact Y detection means movable in parallel to the X-axis for measuring the distance at a right angle between such means and the peripheral surface of the tread profile in the direction of the Y-axis, X detection means for detecting the position of the Y detection means along the direction of the X-axis, data memory means for storing X and Y data pairs obtained by both such detection means, and radius calculating means for calculating the radius of the article from the X and Y data stored in the data memory means. The radius calculating means includes division means for dividing the X and Y data for a plurality of portions of the tread profile based on predetermined reference values for the tread profile of the tire being measured and arithmetic means for determining the radii of the respective portions each from the corresponding data divided by the division means, the arithmetic means determining the circle equation of: x.sup.2 +y.sup.2 +ax+by+c=0, from the X and Y data to calculate the radius of the tread profile, the coefficients a, b and c of the circle equation being determined by least square approximation.

Apparatus and method for determining the profile of the tread of a tire

A tire and an assembly of a rim and a tire are disclosed. The rim has a pair of rim bases, a hump formed axially inside each rim base, and an annular groove formed axially inside each hump. The tire comprises a pair of beads having a bead base seated on the rim base, a pair of bead cores disposed one in each bead, at least one of the beads having a toe and a hump groove disposed between the toe and the bead base, wherein, the tip of the toe is located radially outside a bead base line, and under such condition; that the tire is inflated to a normal internal pressure, the hump groove and the tip of the toe are spaced apart from the hump and the annular groove, and the distance L in the radial direction between the radially outermost point RT of the hump and the radially outermost point PT of the hump groove is not less than 0.5 mm and not more than 2.0 mm.

Tire and rim assembly and tire for use therein

An apparatus for determining the shape of contact patch and the contact pressure of a tire comprises a contact member made of a transparent material, a pressing unit for pressing the outer peripheral surface of the tire against the contact member, a sheet having elastic projections arranged regularly on one surface thereof and uniformly distributed thereover, and an observation device for observing through the contact member the projections as deformed when the tire is pressed against the contact member with the sheet interposed therebetween and with the projections thereof facing the contact member. The shape of contact patch and contact pressure of the tire can be determined by observing deformed projections by the device.

Apparatus for determining shape of contact patch and contact pressure of

A tire and an assembly of a rim and a tire are disclosed. The rim has a pair of rim bases, a hump formed axially inside each rim base, and an annular groove formed axially inside each hump. The tire comprises a pair of beads having a bead base seated on the rim base, a pair of bead cores disposed one in each bead, at least one of the beads having a toe and a hump groove disposed between the toe and the bead base, wherein the tip of the toe is located radially outside a bead base line, and under such condition that the tire is inflated to a normal internal pressure, the hump groove and the tip of the toe are spaced apart from the hump and the annular groove, and the distance L in the radial direction between the radially outermost point RT of the hump and the radially outermost point PT of the hump groove is not less than 0.5 mm and not more than 2.0 mm.

Growing community of inventors

Kobe, Japan

Yasuo Wada