Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord for rubber reinforcement, having improved impregnation property of rubber into the cord and keeping low cord rigidity while keeping the merits of multi-layer twist steel cord comprising high cord strength and good fatigue resistance and provide a pneumatic radial tire produced by using the cord as the reinforcing material. SOLUTION: The steel cord having a three layer twist structure is composed of a core 1 composed of two strands, an intermediate sheath 2 composed of 7 strands wound around the core 1, and an outer-layer sheath 3 composed of 12 strands wound around the intermediate sheath 2. The ratio (ds/dc) of the diameter (ds) of the strand constituting the intermediate sheath 2 and outer layer sheath 3 to the diameter (dc) of the strand constituting the core 1 is 1.0-1.1. Preferably the twisting direction of the intermediate sheath 2 is reverse to that of the outer-layer sheath 3. COPYRIGHT: (C)2007,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord obtained by stranding one layer of sheath filaments consisting of steel while unevenly distributing, around a plurality of core filaments doubled as non-stranded state in parallel and improving the rubber penetrating property by securing the gap between the filaments on vulcanization. SOLUTION: This steel cord is provided by forming at least one piece (a core filament 16, sheath filament 26A) among the core filaments or sheath filaments, as different from those of other core filaments 18 and sheath filaments 26B before stranding so as to secure gaps A, B forcefully between the core filaments and sheath filaments. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord raising the tensile rigidity of a rubber article without causing lowering of durability by occurrence of separation in the periphery of the cord with a slight stretch in a filament bundle of a core and further having a smaller thickness in the cord minor axis direction than that of a flattened cord in which the core maintains a side-by-side arrangement when the steel cord is applied to the rubber article and reducing the coating rubber thickness when the steel cord is applied to the rubber article. SOLUTION: The steel cord is obtained by wrapping M (wherein, M is 1-3) filaments around the core in which N (wherein, N is 3-5) filaments are regularly placed in the mutually parallel side-by-side arrangement and forming a sheath. The contour of the cord defined as a projected locus in the cord longitudinal direction of the sheath filaments wrapped around the core is kept on the inside of the projected locus in the cord longitudinal direction when the sheath filaments make one round around the core of the N filaments. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord for reinforcing a rubber product, useful as a reinforcing material for rubber products such as vehicle tires, industrial belts, or the like with extreme flatness and excellent fatigue resistance. SOLUTION: The steel cord of 3+7 structure has three core wires 2a-2c are arranged mutually approximately in parallel and approximately linearly in one direction in a cord cross section. Side wires 4a, 4d and 4g positioned at both end sides in a longitudinal direction in a cord cross section of a core wire group 3 have gaps between them and the core wires 2a and 2c at both end sides of the core wire group 3, side wires 4b, 4c, 4e and 4f positioned off from both end sides of the core wire group 3 are contacted with any one of the core wires 2a-2c and a side wire filling factor defined by a product of the wire diameter and the number of the side wires to length L of a closed curve obtained by sequentially connecting the centers of the adjacent side wires 4a-4g in the circumferential direction by straight lines is 70-90% to provide the steel cord with flatness and excellent fatigue resistance. COPYRIGHT: (C)2010,JPO&INPIT