US 12,123,475 B2
Core wire for drive belt, drive belt, and method for manufacturing core wire and drive belt
Takuya Tomoda, Hyogo (JP); and Yasushi Hirakawa, Hyogo (JP)
Assigned to Mitsuboshi Belting Ltd., Kobe (JP)
Appl. No. 17/758,312
Filed by Mitsuboshi Belting Ltd., Kobe (JP)
PCT Filed Jan. 13, 2021, PCT No. PCT/JP2021/000915
§ 371(c)(1), (2) Date Jul. 1, 2022,
PCT Pub. No. WO2021/145348, PCT Pub. Date Jul. 22, 2021.
Claims priority of application No. 2020-005388 (JP), filed on Jan. 16, 2020; and application No. 2020-206743 (JP), filed on Dec. 14, 2020.
Prior Publication US 2023/0037131 A1, Feb. 2, 2023
Int. Cl. F16G 1/10 (2006.01); D02G 3/04 (2006.01); D02G 3/28 (2006.01); D02G 3/44 (2006.01); F16G 1/28 (2006.01)
CPC F16G 1/10 (2013.01) [D02G 3/04 (2013.01); D02G 3/28 (2013.01); D02G 3/44 (2013.01); F16G 1/28 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A core wire for a power-transmission belt, comprising a plied twisted cord formed by putting together and secondary twisting a plurality of primary twisted yarns,
wherein the primary twisted yarns comprise a plurality of hard primary twisted yarns (A) and one soft primary twisted yarn (B),
the hard primary twisted yarns (A) comprise an aramid fiber, a fineness of each hard primary twisted yarn (A) is 1500 dtex or less,
the soft primary twisted yarn (B) comprises a low elastic modulus fiber, and
a ratio (B/A) of a primary twist coefficient of the soft primary twisted yarn (B) to an average value of primary twist coefficients of the hard primary twisted yarns (A) is 0.5 to 1.2,
wherein when the plied twisted cord is untwisted by 100 mm and the primary twisted yarns are aligned, a difference (B−A) between a length of the soft primary twisted yarn (B) and an average length of the hard primary twisted yarns (A) satisfies: the length of the soft primary twisted yarn (B)−the average length of the hard primary twisted yarn (A)=−1 mm to 2 mm.