High elongation steel cord with preformed strands
AssigneeNV Bekaert SA
InventorsJavier Del Río Rodriguez, Steven Wostyn
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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.
Claims10
A steel cord with a high elongation at break being at least 5% comprising n strands, said strands being helically preformed, each of said strands having m filaments twisted together, said n ranging from 2 to 7, said m ranging from 2 to 9, said strands and said filaments being twisted in a same direction, a lay length of said cord being Lc and a lay length of said strand being Ls, wherein a ratio of said Ls to said Lc (Ls/Lc) ranges from 0.25 to 1, said Lc ranges from 16 mm to 26 mm, and wherein an E-modulus of said steel cord is more than 150000 N/mm2;
- and wherein said helically preformed strand has a preformation pitch Ps and a preformation amplitude As, said Ps is 50 to 120 times a diameter D of the filament and said As is 8 to 12 times the diameter D of the filament.
A steel cord, with a high elongation at break being at least 5% comprising n strands, said strands being helically preformed, each of said strands having m filaments twisted together, said n ranging from 2 to 7, said m ranging from 2 to 9, said strands and said filaments being twisted in a same direction, a lay length of said cord being Lc and a lay length of said strand being Ls;
- wherein a ratio of said Ls to said Lc (Ls/Lc) ranges from 0.25 to 1, said Lc ranges from 16 mm to 26 mm, wherein an E-modulus of said steel cord is more than 150000 N/mm2;
- and wherein said n is 3 while said in is 7.
A steel cord, with a high elongation at break being at least 5% comprising n strands, said strands being helically preformed, each of said strands having m filaments twisted together, said n ranging from 2 to 7, said m ranging from 2 to 9, said strands and said filaments being twisted in a same direction, a lay length of said cord being Lc and a lay length of said strand being Ls, wherein a ratio of said Ls to said Lc (Ls/Lc) ranges from 0.25 to 1, said Lc ranges from 16 mm to 26 mm, and wherein an E-modulus of said steel cord is more than 150000 N/mm2;
- wherein said helically preformed strand has a preformation pitch Ps and a preformation amplitude As;
- wherein said Ps is 70 to 100 times a diameter D of the filament and said Λs is 9 to 11 times the diameter D of the filament;
- and wherein said Ps is equal to said Lc.
Dependencies are inferred from the claim text.