Abstract:
PROBLEM TO BE SOLVED: To provide an open structure steel cord that has an intended elliptical shape which has a uniform ratio of the minor axis to the major axis in the longitudinal direction of the cord. SOLUTION: The steel cord is a single-layer open-structure steel cord formed of seven or more steel filaments and has a cross-section of an elliptical shape extending continuously in the longitudinal direction of the cord wherein the ratio A/B of the minor axis A to the major axis B in the elliptical shape is 0.4-0.8; the diameter d of the steel filament is 0.12-0.26 mm; and the ratio a/d of the twist pitch (a) of the cord to the diameter d of the steel filament is 30-80. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord which is used for reinforcing rubber products, has good rubber material invasiveness, is free from the slip of a core strand group and an intermediate strand group, has a stable twist structure, is little extended with low loads, and has a three-layered structure. SOLUTION: The cord 10 having an L+M+N structure is produced by twisting intermediate strands 12 each having smaller pitch approximately sine wave-like curls than the pitches of curls for twisting all strands, around a core strand 11, further twisting side strands 13, and then pressing in the direction crossing the longitudinal direction of the cord. A steel cord having a 1×P structure is produced by simultaneously twisting all intermediate strands each having a smaller pitch approximately sine wave-like curls than the pitches of curls for twisting the strands with other strands, and then pressing the twisted product. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a steel cord which is used for reinforcing rubber products, can reduce production cost, has good rubber material invasiveness, is little extended with low loads, and has a two-layered structure. SOLUTION: The method for producing the steel cord 10 comprises forming spiral curls on all core strands 11, pressing the product to form smaller pitch approximately sine wave-like curls than pitches for twisting in an approximately sine wave-like shape, simultaneously twisting the core strands 11 with side strands 12 to form a bundle-twisted two-layered structure, and then pressing the product in the direction crossing the longitudinal direction of the cord. Thus, in the cord 10, the core strands 11 contact with each other at any places in the longitudinal direction of the cord, and are discontinuously arranged in the longitudinal direction of the cord to partially contact in approximate parallel. COPYRIGHT: (C)2009,JPO&INPIT