Abstract:
A steel cord for reinforcing rubber article having a 1×n structure composed of a plurality of steel filaments stranded in the same direction at the same stranding pitch, the number of the steel filaments being 6 to 12 and the diameter of the steel filaments being 0.08 to 0.21 mm. In the pneumatic radial tire having a carcass, as a framework, extending toroidally between a pair of bead parts, with a crown part of the carcass being reinforced with a belt layer, the above-described steel cord for reinforcing rubber article is applied to a cord constituting the belt layer.
Abstract:
There is provided a steel cord including a plurality of untwisted core filaments of steel aligned in parallel, and a layer of sheath filaments of steel twisted around the core filaments so as to be unevenly distributed around the core filaments, wherein interstices between the filaments are maintained during vulcanization thereby achieving improved rubber penetration (sufficiently adhering rubber to the core filaments). Since the cross sectional length of the steel cord 10 is greater than the minimum cross sectional length, interstices A are maintained between sheath filaments 14 under the tension and pressure p of the surrounding rubber 16 applied to the steel cord 10 during vulcanization. Rubber 16 penetrates into the steel cord 10 through the interstices A, and sufficiently adhere to core filaments 12 to achieve high rubber penetration.
Abstract:
Provided is a pneumatic tire for heavy loads in which durability and a desired rigidity in circumferential direction are simultaneously attained while achieving a reduction in the tire weight.The present invention is a pneumatic tire for heavy loads having at least one layer of steel belt in which a plurality of steel cords 1, each of which is constituted by a plurality of intertwisted filaments 11, are arranged in parallel in the form of bundles. In the pneumatic tire for heavy loads, the height of cord bundles 2, that is, the minor axis (A) (mm) of the steel cords 1 and the bundle width (B) (mm), satisfy the relationship represented by the following Formula (1): B/A≧2.0 (1), and at the same time, the value of S=B/(B+D), which is defined by the bundle width (B) (mm) of the cord bundles 2 and the distance (D) (mm) between the cord bundles, satisfies the relationship represented by the following Formula (2): 0.60≦S≦0.80 (2).
Abstract:
There is provided a steel cord including a plurality of untwisted core filaments of steel aligned in parallel, and a layer of sheath filaments of steel twisted around the core filaments so as to be unevenly distributed around the core filaments, wherein interstices between the filaments are maintained during vulcanization thereby achieving improved rubber penetration (sufficiently adhering rubber to the core filaments). Since the cross sectional length of the steel cord 10 is greater than the minimum cross sectional length, interstices A are maintained between sheath filaments 14 under the tension and pressure p of the surrounding rubber 16 applied to the steel cord 10 during vulcanization. Rubber 16 penetrates into the steel cord 10 through the interstices A, and sufficiently adhere to core filaments 12 to achieve high rubber penetration.
Abstract:
A steel cord which has no production problem noted in the related art and which can be produced efficiently with stable quality, particularly a steel cord useful for the purpose of reinforcing a tire crown portion, as well as a composite of rubber and steel cord and a tire, which include the steel cord, are provided.A steel cord has a multi-twist structure in which N (N=2 to 8) strands 2 are twisted, each strand 2 being formed by twisting a plurality of element wires 1 and having a substantially elliptical cross-section, wherein d1/d2>1.08 is satisfied, where the major diameter of the strand 2 is represented by d1 and the minor diameter is represented by d2, and εc defined by the following equation: εc=√{square root over ( )}(−b/2+√{square root over ( )}(b2/4−c))−1 (in the equation, b represents −1+π2(−4R2+d2)/P2, c represents π2d2k(4π2R2+P2)/P4, R represents (D−d)/2, k represents tan2(π/2−π/N), and d represents (d1+d2)/2) satisfies εc>0.005, where the diameter of a circle circumscribing the cord is represented by D (mm) and the twist pitch of the cord is represented by P (mm).
Abstract:
There is provided a steel cord for reinforcing rubber article having superior durability, and a pneumatic radial tire improved in steering stability and durability by using it. There is also provided a pneumatic radial tire satisfactorily combining steering stability, durability, and good cost performance required for a high performance radial tire intended for the application to a high performance passenger car. The steel cord for reinforcing rubber article has a 1×n structure composed of a plurality of steel filaments stranded in the same direction at the same stranding pitch, wherein the number of the steel filaments is 6 to 12 and the diameter of the steel filaments is 0.08 to 0.21 mm. In the pneumatic radial tire having a carcass (1), as a framework, extending toroidally between a pair of bead parts (11), with a crown part of the carcass being reinforced with a belt layer (2), the above-described steel cord for reinforcing rubber article is applied to a cord constituting the belt layer.
Abstract:
A pneumatic tire comprises a tread portion, a pair of sidewall portions, a pair of bead portions, and a carcass ply of steel cords extending between the bead portions through the tread portion and sidewall portions. Each of the carcass cords comprises a number nullnnull of steel filaments each having a diameter (d) of from 0.17 to 0.40 mm. The steel filaments are twisted together to have a null1nullnnull bundle-twist structure or an interlace-twist structure. In a vicinity of the maximum tire section width point P of each of the sidewall portions, a sectional shape coefficient S of each carcass cord is set in a range of from 0.5 to 0.9, wherein the sectional shape coefficient S is (d2nulln)/(L1nullL2), nullnnull is the number of the filaments, nulldnull is the average of the diameters of the filaments, nullL1null is the largest measure of distance between two extremities of the cord which occurs in a direction in a cross section of the cord, and nullL2null is the measure of distance between two extremities of the cord in a direction perpendicular to the above-mentioned direction.
Abstract:
A steel cord for the reinforcement of rubber article having M parallel+N structure consists of a core of two steel filaments and a single sheath of seven or eight steel filaments, wherein diameters of core filament and sheath filament and twisting pitch have specified ranges, respectively.
Abstract:
A method for using a bunching type twisting machine to manufacture a steel cord made up of one core filament having a continuous wavy form and five to eight sheath filaments not having a wavy form disposed around the core filament, the cross-sectional shape of the cord forming an ellipse whose orientation is substantially constant in the length direction of the cord. After a core filament is preformed with a helical wavy form of a smaller pitch than the cord twisting pitch, this is squashed to form a flat helical core filament at a stage before it is twisted together with sheath filaments, and then sheath filaments are twisted around this flat helical core filament to make an intermediate product cord and this intermediate product cord is then squashed and thereby flattened before being taken up on a reel.
Abstract:
The steel cord has the 1.times.9 structure, in which three core wires and six thicker outer wires are twisted in the same direction with the same pitch, and has a flat shape in the section which is taken perpendicularly to the longitudinal section thereof. The six outer wires having at least two gaps between adjacent ones and the core wires have at least one gap between adjacent ones.