US 12,247,352 B2
Steel cord and manufacturing process therefor
Xiang Liu, Jiangsu (CN); Aiping Wang, Jiangsu (CN); Nianpeng Zhao, Jiangsu (CN); Weiming Ma, Jiangsu (CN); Xianghui Liu, Jiangsu (CN); Chundong Pan, Jiangsu (CN); and Cunjun Zhao, Jiangsu (CN)
Assigned to Jiangsu Xingda Steel Tyre Cord Co., Ltd., (CN)
Appl. No. 17/760,665
Filed by Jiangsu Xingda Steel Tyre Cord Co., Ltd., Jiangsu (CN)
PCT Filed Apr. 30, 2021, PCT No. PCT/CN2021/091412
§ 371(c)(1), (2) Date Mar. 15, 2022,
PCT Pub. No. WO2022/142034, PCT Pub. Date Jul. 7, 2022.
Claims priority of application No. 202011579287.X (CN), filed on Dec. 28, 2020.
Prior Publication US 2024/0044075 A1, Feb. 8, 2024
Int. Cl. D07B 9/00 (2006.01); B60C 9/00 (2006.01); D07B 1/06 (2006.01)
CPC D07B 1/062 (2013.01) [B60C 9/0007 (2013.01); D07B 2201/102 (2013.01); D07B 2201/104 (2013.01); D07B 2201/2006 (2013.01); D07B 2201/2009 (2013.01); D07B 2201/2066 (2013.01); D07B 2205/3025 (2013.01); D07B 2401/2095 (2013.01); D07B 2501/2046 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A manufacturing method for a steel cord, wherein, the steel cord comprises:
a steel core wire located in a center and having a diameter of d;
M sheath-layer steel wires arranged around the steel core wire in the center, tangent to the steel core wire, and having a diameter of d1, at least two gaps L existing between the M sheath-layer steel wires, wherein M is 4;
d, d1, and L satisfy a relationship:
0.420<(d/d1)<0.800;
d1 is between 0.20 mm and 0.44 mm; and
L≥0.0008 mm;
wherein,
in a twisting process, a steel core wire and M sheath-layer steel wires are simultaneously unwound, an unwinding tension of the sheath-layer steel wires being equal, and the unwinding tension of the steel core wire being greater than that of each sheath-layer steel wire; and the steel core wire is placed in the center, and the M sheath-layer steel wires are uniformly distributed at 360° and bundled together around the steel core wire for twisting.