The Yokohama Rubber Co., Ltd.

Ken Takahashi

Kazuyuki Kabe

Tatsuo Suzuki

Masashi Kida

Tsuyoshi Maekawa

Norio Ohmoto

Osamu Takahashi

Masataka Koishi

Masahiko Kanamaru

Yukio Kaga

Heikichi Nakanome

Hajime Tomoda

Kazuyuki Kaba

Kazuo Teramoto

Saichi Harada

Disclosed is a method of manufacturing a radial tire for a construction vehicle, wherein when a cylindrical band is formed by using one layer of carcass layer formed of steel cords in a band making step, a shape retaining layer formed of at least one layer of organic fiber cords is wrapped on the outer peripheral surface of the carcass layer so that the organic fiber cords cross the steel cords of the carcass layer. The radial tire having excellent uniformity without any uneven widening between the steel cords can be provided without using a shape retaining auxiliary apparatus.

Method of manufacturing radial tire for construction vehicle

A method of producing a radial tire for a construction vehicle, the method enabling a vast reduction in facility costs. A first green tire is formed in a first step molding machine and then removed from it. After that, a vulcanizer bladder unit is installed on the tire. The tire is inflated by the vulcanizer bladder unit and then again placed in the first step molding machine with the vulcanizer bladder unit installed. After that, on the first step molding machine, belts and tread rubber are adhered to the outer periphery of the tire to form a completed green tire. Then the completed green tire, with the vulcanizer bladder unit, is assembled in a vulcanizing mold for vulcanization.

Method of producing radial tire for construction vehicle

A pneumatic radial tire having a tread formed from a rubber strip-stacked body by stacking rubber strip layers composed of a rubber strip wound spirally while continuously joining side surfaces thereof to each other in a tire circumferential direction on the outside of a carcass layer via a belt layer, in which boundary surfaces of the rubber strip of the rubber strip-stacked body forming at least an outermost layers of both shoulder portions of the tread are leaned respectively toward the outside of a tire diameter direction relative to a tire outside direction in a tire width direction.

Pneumatic radial tire and method of manufacturing the same

In a heavy duty pneumatic radial tire, at least one carcass layer is provided between right and left bead portions and at least two belt layers formed of steel cords which exhibit a breaking elongation of 4% or less are arranged in an outer periphery of the carcass layer in a tread portion. The belt layers are composed of at least one upper belt layer (A) and at least one lower belt layer (B). The upper belt layer (A) has a belt width that is 0.6 times or less a carcass line maximum width SW of the carcass layer at a tire section and the lower belt layer (B) has a belt width such that both end portions thereof extend to tread shoulder portions. An inclination angle of the steel cords of the lower belt layer (B) relative to a tire circumferential direction is set to be larger than that of the upper belt layer (A). A ratio (Mb.sub.2 .multidot.N.sub.2)/( Mb.sub.1 .multidot.N.sub.1) of a product of a bending rigidity Mb.sub.2 per steel cord of the lower belt layer (B) and the number N.sub.2 of the steel cords per unit width of the lower belt layer (B) to a product of a bending rigidity Mb.sub.1 per steel cord of the upper belt layer (A) and the number N.sub.1 of the steel cords per unit width of the upper belt layer (A) is set to be at a range of 0.2 to 0.65.

Heavy duty pneumatic radial tire for running on rough ground surface

A pneumatic radial tire comprising a carcass layer, a tread portion and a belt layer disposed therebetween, the belt layer having a structure composed of at least two layers, wherein the belt layer is formed at least at a central portion of the cross section thereof to have a parallel portion substantially parallel to the axis of rotation of the tire over a width corresponding to 30 to 50% of the maximum width of the belt layer; and the carcass layer is formed in such a manner that when the tire is mounted on a rim and filled with air to 10% of a normal internal pressure, a portion corresponding to the parallel portion of the belt layer has a profile of a carcass line joined parallel to the parallel portion and a portion tangentially extending from the edge of the parallel portion and leading through the maximum width portion of the tire to at least the upper edge of a bead filler has a profile of a carcass line comprising arcs having substantially the same radius of curvature.

Pneumatic radial tire carcass line profile

A pneumatic radial tire having such a radial cross-section that the profile of the outer surface of the tire side is composed of a plurality of straight lines and each intersection at which the straight lines meet with each other is formed so as to protrude in the outward direction of the cross-section of the tire.

Pneumatic radial tire profile

A heavy duty and medium pneumatic radial tire having a belt layer composed of at least three layers between a carcass layer and a tread, wherein the first belt layer as numbered from the carcass layer towards the tread is separated into two parts at the central region of a crown and at least one organic fiber cord layer is disposed in a space formed by the separation of the first belt layer.

Heavy duty and medium pneumatic radial tire

A radial tire with a split structure in the first belt layer provided with an organic fiber cord layer in the split structure and having a narrow groove extending in the circumferential direction of the tire and provided in each of both shoulder portions of the surface of a tread, wherein the narrow groove has a depth h determined in the radial direction of the tire, and a distance d.sub.1 measured between the internal edge on the shoulder side of an opening portion of the narrow groove and the radially outermost surface of the shoulder portion as determined along a parallel line to the surface of the tread, and a distance d.sub.2 measured between the internal wall surface on the shoulder side of the bottom of the narrow groove and the radially outermost surface of the shoulder portion as determined along a parallel line to the surface of the tread, wherein d.sub.1 is less than 15 mm and is smaller than d.sub.2, and a shape factor m defined by the following equation is 0.8 to 1.2: ##EQU1##

Pneumatic radial tire

A heavy-duty radial tire having a belt layer comprising at least four metallic cord layers of first, second, third, and fourth belts in that order from the carcass layer towards the tread. The first belt has a cord angle of 40.degree. to 75.degree. relative to the circumferential direction of the tire and is split into left and right portions provided on left and right shoulder portions, respectively, so as to provide a space in the central region of a crown portion provided with either at least one organic fiber cord layer having a total tensile strength per unit width of at least 240 kgf/cm and a cord angle of 0.degree. to 10.degree. or an inextensible fiber cord layer having a two-layer structure wherein the sum of the tensile moduli per unit width in the initial tension of all the cords is at least 1.3.times.10.sup.3 kgf/cm, the cord angle is larger than 0.degree. and two layers in the two-layer structure cross each other at an absolute angle smaller than the cord angle of the second and third belts. The second belt comprises cords provided at a cord angle of 22.degree. to 30.degree.. The third belt comprises cords crossing the cords constituting the second belt and provided at a cord angle of 10.degree. to 16.degree.. The fourth belt comprises cords provided at a cord angle of at least 18.degree..

Heavy-duty pneumatic radial tire

An improvement in the structure of the belt portion of a heavy duty radial tire for use in trucks, large-size buses, small-sized trucks, etc., and more particularly, a heavy duty pneumatic radial tire improved with respect to the driving stability under heavy duty conditions while ensuring the durability of the tire (belt portion) during high speed running through the provision of at least three belt layers between the tread surface and the carcass layer of the tire and the specification of the relationships between the angles of the cords constituting these plurality of belt layers.

Heavy duty pneumatic radial tire

A heavy load radial tire is disclosed, wherein a sub-carcass layer having a cord angle substantially equal to that of a carcass layer is disposed on the carcass layer, and at least one belt layer whose cords cross at right angles the cords of the sub-carcass layer is disposed on the sub-carcass layer.

Heavy load radial tire

Heavy-duty pneumatic radial tire tread with narrow groove near shoulder

In a pneumatic tire of a structure in which a belt-reinforcing layer is overlaid and interposed between a tread and a carcass cord layer, the belt-reinforcing layer consisting of a transient-reinforcing layer positioned in contact with the carcass cord layer with its reinforcing cords disposed at an angle of between 40.degree. to 75.degree. with respect to the circumferential direction of the tire, and at least two belt-resistant layers, the lower one thereof being laid over the transient-reinforcing layer with its reinforcing cords disposed at an angle of between 15.degree. to 30.degree. with respect to the circumferential direction of the tire, and the upper one with its reinforcing cords disposed at an angle of between 150.degree. to 165.degree. thereto, the tire is improved in that the carcass cord layer is formed of a single layer and the reinforcing cords in the carcass cord layer are arranged so that their angle with respect to the circumferential direction of the tire is between 75.degree. to 85.degree. when measured from the side on which the angle of the reinforcing cords in the transient-reinforcing layer is an acute angle with respect to the circumferential direction of the tire.

Pneumatic tire

A pneumatic tire for heavy duty trucks, provided in the tread thereof with lug grooves, auxiliary grooves having smaller depth and smaller width than the lug grooves, one-side ends of the auxiliary grooves opening into lateral walls of the lug grooves, and a shelf part disposed on the lateral walls of the lug grooves containing the openings at a level flush with the bottom surface of the auxiliary grooves.

Pneumatic tire tread for heavy duty trucks

A pneumatic tire having a carcass ply of metal cords arranged and embedded in the radial direction in a rubber is disclosed. This carcass ply has a natural sectional profile, and the position of the carcass ply in the shoulder portion of the tire satisfies the requirement of 0.3.ltoreq.t.sub.2 /t.sub.1 .ltoreq.1.0 in which t.sub.2 designates the thickness of the tire inside the carcass ply and t.sub.1 designates the thickness of the tire outside the carcass ply. In this shoulder portion, the thickness of an inner liner layer inside the carcass cord is gradually reduced toward the center of the tire top and the maximum width position of the tire. This pneumatic tire is preferably used for a high-load vehicle.

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Hiratsuka, Japan

Ken Takahashi