Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord for rubber reinforcement which satisfies all properties of fatigue resistance, cutting resistance and corrosion resistance and further improved in durability and a pneumatic radial tire using the steel cord as a reinforcing material. SOLUTION: The steel cord for rubber reinforcement is composed of a core strand 2 having two or more layers-twisted structure and a sheath strand 1 surrounding the core strand 2. The twist structure of the sheath strand 1 is represented by the formula n×m. The relationship between a diameter d1 of the sheath strand 1 and a diameter d2 of the core strand 2 is preferably represented by the formula d2≥d1. The elongation E1 which results in fracture of the sheath strand 1 is preferably represented by the formula E1≥1.5 (%). COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
The invention relates to a hybrid rope comprising a core element, a first and a second metallic closed layer surrounding said core element. The core element includes a bundle or construction of synthetic yarns. The first metallic closed layer includes a plurality of first wirelike members helically twisted together with the core element in a first direction. The second metallic closed layer includes a plurality of second wirelike members helically twisted together with said core element and said first metallic closed layer in a second direction. The cross-sectional area of the core element is larger than the total cross-sectional area of the first and second metallic closed layers.
Abstract:
A steel cord (30) with a high elongation at break of at least 5% comprises n strands (20), each of said strands (20) has m filaments (10) twisted together, n ranges from 2 to 7. m ranges from 2 to 9. The strands and the filaments are twisted in a same direction. The lay length of the cord is Lc and the lay length of said strand is Ls. The ratio of Ls to Lc (Ls/Lc) ranges from 0.25 to 1. Lc ranges from 16 mm to 26 mm. The strands are helically preformed. The E-modulus of the cord is more than 150000 N/mm2. The helical preforming of the strands allows to obtain a high elongation at break and a high E-modulus despite its long lay length Lc.