Steel cord comprising flat wires

• US 9,109,328 B2
• Filed: 05/03/2012
• Issued: 08/18/2015
• Est. Priority Date: 06/10/2011
• Status: Expired due to Fees

• Current Assignee: NV Bekaert SA
• Original Assignee: NV Bekaert SA
• Inventors: Wang, Pengfei, Cheng, Zhichao, Chen, Jiankao, Luo, Yiwen
• Primary Examiner(s): Hurley, Shaun R
• Application Number:
  US14/124,921
• Publication Number:
  US 20140099515A1
• Time in Patent Office: 1,202 Days
• Field of Search: 572/10, 572/12
• US Class Current: 1/1
• CPC Class Codes: B60C 9/0007 Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal
• CPC Class Codes: D02G 3/48 Tyre cords tyre reinforcements B60C9/00; metal cords for reinforcing rubber or plastic articles D07B1/0606
• CPC Class Codes: D07B 1/062 the reinforcing cords being characterised by the strand configuration
• CPC Class Codes: D07B 2201/2003 flat
• CPC Class Codes: D07B 2201/2011 comprising metals
• CPC Class Codes: D07B 2201/2018 oval
• CPC Class Codes: D07B 2201/2033 Parallel wires
• CPC Class Codes: D07B 2201/2098 characterized by special properties or the arrangements of the binding wire
• CPC Class Codes: D07B 2205/2046 Polyamides, e.g. nylons
• CPC Class Codes: D07B 2205/3035 Pearlite
• CPC Class Codes: D07B 2205/3089 Brass, i.e. copper (Cu) and zinc (Zn) alloys
• CPC Class Codes: D07B 2501/2007 Elevators
• CPC Class Codes: D07B 2501/2046 Tire cords
• CPC Class Codes: D07B 2501/2076 Power transmissions
• CPC Class Codes: D07B 2801/10 Smallest filamentary entity of a rope or strand, i.e. wire, filament, fiber or yarn
• CPC Class Codes: D07B 2801/18 Coating
• CPC Class Codes: D10B 2331/02 polyamides D10B2331/08 takes precedence
• CPC Class Codes: Y10T 428/12333 Helical or with helical component
• CPC Class Codes: Y10T 428/249922 Embodying intertwined or helical component[s]
• CPC Class Codes: Y10T 428/2936 Wound or wrapped core or coating [i.e., spiral or helical]

Abstract

A steel cord (20) comprises a plurality of steel filaments (22, 24) arranged in parallel to the longitudinal axis of the steel cord (20) without twisting. The steel cord (20) further comprises a wrapping filament (26) twisted around the steel cord (20). Each of said steel filaments (22, 24) is a flat wire having flat surfaces. The steel filament (24) near the center of the steel cord (20) has a bigger width than the steel filaments (22) further away from the center of the steel cord (20) such that the cross-section of said steel cord (20) approximates an oval shape with the bending stiffness around the shorter axis of the oval shape being greater than the bending stiffness around the longer axis. In a tire, the steel cord being used as a reinforcement, the longer axis being arranged perpendicular to the radial direction of the tire.

Claims

1. A steel cord comprising a plurality of steel filaments arranged in parallel without twisting, said steel cord further comprising a wrapping filament twisted around said steel filaments, said plurality of steel filaments being flat wires having flat surfaces, said plurality of steel filaments being in contact with each other along said flat surfaces, the lateral bending stiffness (in a horizontal plane) is greater than the radial bending stiffness (in a vertical plane),

wherein the cross-section of said steel cord is substantially round,

wherein said steel filaments have different cross-sectional areas,

wherein said steel filament near the center of said steel cord has the bigger cross-sectional area, and said steel filament further away from the center of said steel cord has the smaller cross-sectional area.

2. A steel cord as claimed in claim 1, wherein the ratio of said lateral bending stiffness to said radial bending stiffness is not less than 1.8.

3. A steel cord as claimed in claim 2, wherein the ratio of said lateral bending stiffness to said radial bending stiffness is not less than 2.0.

4. A steel cord as claimed in claim 1, wherein said steel filament near the center of said steel cord has a bigger width, and said steel filament far away from the center of said steel cord has a smaller width.

5. A steel cord as claimed in claim 1, wherein the number of said plurality of steel filaments is between 3 and 9.

6. A steel cord as claimed in claim 1, wherein said wrapping filament is a filament with a flat cross-section or a round cross-section.

7. A steel cord as claimed in claim 1, wherein said wrapping filament is a nylon filament or a metallic filament.

8. A steel cord as claimed in claim 1, wherein said steel cord has a diameter ranging from 0.2 mm to 15 mm.

9. A rubber product comprising the steel cord as claimed in claim 1, wherein the steel cord is arranged as a reinforcing element in the rubber product.

10. A rubber product as claimed in claim 9, wherein said rubber product is a belt for a rubber tire, a timing belt, a rubber track tire or a belt for an elevator.