CRIMPED FLAT WIRE AS CORE OF OVAL CORD

• US 20110290397A1
• Filed: 11/23/2009
• Published: 12/01/2011
• Est. Priority Date: 01/28/2009
• Status: Active Grant

• Current Assignee: NV Bekaert SA
• Original Assignee: NV Bekaert SA
• Inventors: Pille, Johan, Loncke, Lieven, Rodriguez, Javier Del Río
• Granted Patent: US 8,720,175 B2
• Time in Patent Office: Days
• US Class Current: 152/526
• CPC Class Codes: B60C 9/0007 Reinforcements made of metallic elements, e.g. cords, yarns, filaments or fibres made from metal
• CPC Class Codes: B60C 9/0057 Reinforcements comprising preshaped elements, e.g. undulated or zig-zag filaments
• CPC Class Codes: D07B 1/0653 in the core
• CPC Class Codes: D07B 2201/2003 flat
• CPC Class Codes: D07B 2201/2018 oval
• CPC Class Codes: D07B 2201/2023 with core
• CPC Class Codes: D07B 2201/2048 characterised by their cross-sectional shape
• CPC Class Codes: D07B 2201/2059 comprising wires
• CPC Class Codes: D07B 2501/2046 Tire cords
• CPC Class Codes: D07B 2801/12 Strand
• CPC Class Codes: D07B 2801/14 Core
• CPC Class Codes: D07B 7/025 Preforming the wires or strands prior to closing
• CPC Class Codes: Y10T 152/10765 Characterized by belt or breaker structure
• CPC Class Codes: Y10T 428/2922 Nonlinear [e.g., crimped, coiled, etc.]
• CPC Class Codes: Y10T 428/2973 Particular cross section

Abstract

A steel cord (10) adapted for the reinforcement of rubber products, the steel cord comprises a core (12) and a layer of filaments (14) with round cross-sections twisted around the core (12). The core (12) comprises a flat wire at a waveform, which lies in the plane of the flat wire. The wire is obtainable by first crimping a round wire and thereafter flattening the crimped wire. The filaments of the layer do not substantially contact each other to make spaces between each other to insure adequate rubber penetration into the cords. The steel cord has improvements on elongation at break.

Claims

1. A cord, adapted for the reinforcement of belt plies in a pneumatic tire, comprising a layer and a core, said layer comprising steel filaments that are wound around the core, said core comprises a flat wire at a waveform, characterized in that the wire is obtainable by first crimping a round wire and thereafter flattening the crimped wire.

2. A cord as claimed in claim 1, characterized in that said wire has an elongated cross-section with a ratio of a width W to the thickness T is 1.2≦

W/T≦

3.0.

3. A cord as claimed in claim 1, characterized in that said waveform lies in the plane of the wire.

4. A cord as claimed in claim 1, characterized in that the pitch Pc of said waveform is in a range from 3.0 mm to 15.0 mm.

5. A cord as claimed in claim 1, characterized in that the amplitude Lc of said waveform is in a range from 0.1 mm to 5.0 mm.

6. A cord as claimed in claim 1, characterized in that said filaments in the layer around the core have a round cross-section.

7. A cord as claimed in claim 1, characterized in that at least two of said filaments in the layer around the core do not substantially contact each other.

8. Use of a cord according to claim 1 as reinforcement of belt plies.

12. A cord as claimed in claim 3, characterized in that the pitch Pc of said waveform is in a range from 3.0 mm to 15.0 mm.

13. A cord as claimed in claim 3, characterized in that the amplitude Lc of said waveform is in a range from 0.1 mm to 5.0 mm.

9. A flat wire adapted for reinforcement of rubber products characterized in that said flat wire is wavy in the plane of the flat wire.

10. A flat wire according to claim 9 obtainable by a process of crimping a round wire followed by flattening said crimped round wire.

11. A method of manufacturing a cord adapted for the reinforcement of belt plies in a pneumatic tire, said method comprising the following steps:

providing a round steel wire;

crimping said round steel wire;

flattening said crimped round steel wire;

winding other steel wires around said flattened and crimped steel wire.