Sumitomo Rubber Industries Limited

Sumitomo Electric Industries, Limited

Other

Osamu Toda

Shinichi Miyazaki

Kazumi Yamazaki

Yasuo Sakai

Yuichi Sano

Takeshi Ohta

Takuji Kusumoto

A pneumatic tire comprises a cord-reinforced layer such as carcass, belt, bead reinforcing layer which is made of metallic cords, each metallic cord is made up of six to twelve metallic filaments whose diameter is in a range of from 0.15 to 0.45 mm, the metallic filaments include waved filaments and unwaved filaments, each waved filament is two-dimensionally waved at a wave pitch and wave height before twisted, the wave pitch is in a range of from 5.0 to 35.0 times the diameter of the filament, and the wave height is in a range of from 0.2 to 4.0 times the diameter of the filament, and the metallic filaments are twisted together into the cord at a twist pitch of from 10 to 40 mm so that the two-dimensionally waved filaments are each subjected to a certain rotation around its axial.

Pneumatic tire

A pneumatic tire is provided which includes a carcass extending between bead portions, and a belt disposed radially outside the carcass in the tread portion. At least one of the carcass and belt includes a cord ply of a polyethylene-2,6-naphthalate fiber cord. The polyethylene-2,6-naphthalate fiber cord has a total denier number of from 2500 to 3600, a twist number of from 30 to 40 turns/10 cm, an initial stage modulus at 25 deg. C. in a range of from 50 to 65 gf/d, and a variation of the initial stage modulus at between 25 to 70 deg. C. which is not more than 20% in absolute value.

A method of manufacturing a rubber reinforcing steel cord is provided, wherein the steel cord has a steel wire plated with metal containing copper and having on its surface an oil layer containing a cobalt compound, and includes an application step in which the oil containing a cobalt compound is applied to the steel wire or a steel cord plated with metal containing copper, and a step of twisting the steel wires.

Rubber reinforcing steel cord, manufacturing method of rubber reinforcing steel cord and pneumatic tire

A metal cord for reinforcing rubber articles and a pneumatic tire including metal cords to reinforce tire components such as carcass, breaker and band are disclosed, wherein a metal cord according to one aspect of the present invention comprises filaments having a tensile strength of from 4000 to 5500 N/sq.mm and a diameter of from 0.10 to 0.35 mm and the filaments are twisted together, the filaments before twisted are two-dimensionally waved so that the elongation after fracture of the cord becomes in a range of from 2 to 6%. According to another aspect of the present invention, the metal cord is a single filament having a tensile strength of from 4000 to 5500 N/sq.mm and a diameter D of from 0.10 to 0.35 mm, and the filament is two-dimensionally waved so that the elongation after fracture becomes in a range of from 2 to 6%.

Metal cord and pneumatic tire including the same

The present invention provides a metallic cord for reinforcing a tire moldable in a tire manufacturing step without complicating operations and keeping strength by reducing rusting and an excellent pneumatic tire employing the metallic cord. The inventive metallic cord for reinforcing a tire is formed by shaping a bundle prepared by paralleling a plurality of metallic wires having substantially circular sections in an unstranded state with a binder of a polymer material having a melting point of 50&#xb0; C. to 200&#xb0; C. The polymer material is preferably low-density polyethylene or medium-density polyethylene. The diameters of the metallic wires are preferably 0.15 to 0.3 mm.

Metallic cord and pneumatic tire employing the metallic cord

A steel cord is composed of three to six steel filaments each having a filament diameter of from 0.25 to 0.45 mm, the three to six steel filaments including shaped filaments and twisted together, wherein the shaped filaments are, before twisted together, coiled to be set in a form of coil having a coil diameter of less than 5 mm and a coil pitch of more than 5 mm, the shaped filaments include at least two kinds of shaped filaments which are different in respect of the form of coil, the shaped filaments are twisted together while the coil diameter is reduced, the elongation of the cord at 50 N load is less than 0.2%, and the cord strength is in a range of from 2500 to 3500 N/sq.mm.

Steel cord, method of making the same and pneumatic tire including the same

A method for making a metallic cord made up of one or more metallic wires comprises: making at least two layers of at least two metallic elements including copper and zinc on the surface of a base wire; heating the layers to cause the metallic elements thermodiffusion to transform into a primary alloy layer; making a layer of copper on the primary alloy layer; drawing the wire provided with the primary alloy layer and outer copper layer into a metallic wire through dies so that the outer copper layer is diminished during passing through the dies, and a secondary alloy layer is formed as a result of transformation of the primary alloy layer and the outer copper layer which is caused by frictional heat during passing through the dies.

Method for making metallic cord

A pneumatic tire comprises a carcass ply of cords extending between bead portions through a tread portion and sidewall portions, the carcass cords include main cords for reinforcing purpose and auxiliary cords for controlling the outflow of topping rubber during vulcanization, the main cords and auxiliary cords are arranged alternately in the tire circumferential direction, and the number of auxiliary cord(s) between the main cords is in a range of from one to three.

Pneumatic tire with carcass ply including main cords and auxiliary cords

A pneumatic tire comprises a carcass extending between the bead portions and a band disposed radially outside the carcass in a tread portion and made of at least one cord laid at an angle of not more than 5 degrees with respect to the tire equator, and the band cord is made of steel filaments twisted together so as to have a variable elasticity modulus which has a transitional point from under 1000 kgf/sq.mm to over 1000 kgf/sq.mm at an elongation percentage in a range of from 1% to 5%. Preferably, the average elasticity modulus ELn of the cord from zero elongation to the transitional point is in a range of from 500 to 750 kgf/sq.mm, and the average elasticity modulus EHn of the cord from the transitional point to a breaking point of the cord is in a range of from 1200 to 3000 kgf/sq.mm.

Pneumatic tire variable elasticity modules metallic band cord

A metallic cord is composed of metallic filaments gathered together, the metallic filaments include at least one patterned filament which is, before gathered together, two-dimensionally waved so as to have a wave form defined by plural kinds of cycles different from each other in respect of the wave length and/or wave height. A pneumatic tire includes the metallic cords as its carcass cords.

Metallic cord and carcass ply of pneumatic tire including same

A composite cord is provided which is simple in manufacture, highly productive, less costly, and improved in rubber penetration. The composite cord has a 1&times;n construction (n is an integer from 3 to 12) with 2 to 11 metallic filaments and 1 to 5 polymer fibers having a melting point of 50 to 200 degrees twisted together. The pneumatic tire employing this composite cord for its reinforcing element is restricted in rust formation and improved in strength retention.

Composite cord and pneumatic tire using the composite cord

The invention improves rubber permeability while making a cord diameter compact. A metal cord is constituted by a layered structure having a core comprising totally 6 to 12 filaments sectioned into 1 to 4 filament bundles, and a sheath comprising 8 to 15 filaments arranged around the core. Each of the filament bundles includes a waved filament modeled in a two-dimensional wave shape and a non-waved filament, in a state before being bundled. The core makes the wave of the waved filament three-dimensional within the core by applying torsion to each of the filament bundles.

Radial tire for heavy load with specified metal carcass cord

A cord for reinforcing a tire formed by shaping a bundle prepared by paralleling a plurality of metallic wires having substantially circular sections in an unstranded state with a binder of a polymer material having a melting point of 50&deg; C. to 200&deg; C. The polymer material is preferably low-density polyethylene or medium-density polyethylene. The diameters of the metallic wires are preferably 0.15 to 0.3 mm.

A pneumatic tire comprises a tread reinforcing belt made of metallic cords, each of the metallic cords is made up of six to twelve metallic filaments whose diameter is not less than 0.15 mm but less than 0.25 mm, the six to twelve metallic filaments are grouped into a plurality of bunches each including two to four filaments, the filaments of each bunch are twisted together at a first twisting pitch, the bunches are twisted together into the cord at a final twist pitch Pc of from 10 to 40 mm, the first twisting pitch is more than the final twist pitch, and the bunches each include at least one waved filament which is two-dimensionally waved at wave pitches Pw in a range of from 5 to 30 times the diameter (d) of the filament and a wave height (h) in a range of from 0.2 to 3.0 times the diameter (d).

Growing community of inventors

Kobe, Japan

Osamu Toda