Steel cord for reinforcing rubber article, and pneumatic tire using same

Patent metadata

Field	Value
Publication number	US-10105991-B2
Application number	US-201515504526-A
Country	US
Kind code	B2
Filing date	Sep 3, 2015
Priority date	Oct 1, 2014
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

This steel cord for reinforcing a rubber article includes one core strand having a two-layer twisted layer structure formed by intertwining a plurality of steel filaments, and a plurality of sheath strands having a twisted layer structure formed by intertwining a plurality of steel filaments. The sheath strands are intertwined around the core strand, a core of the core strand is formed by two core filaments, and the diameter of outermost layer sheath filaments forming an outermost layer sheath of each sheath strand is greater than the diameter of filaments inside the outermost layer sheath of the sheath strand.

First claim

The invention claimed is:

1. A steel cord for reinforcing a rubber article, the steel cord comprising:
one core strand having a two-layer twisted layer structure formed by intertwining a plurality of steel filaments; and
a plurality of sheath strands having a twisted layer structure formed by intertwining a plurality of steel filaments;
wherein the sheath strands are intertwined around the core strand; and
wherein a core of the core strand is formed by two core filaments, and a diameter of outermost layer sheath filaments forming an outermost layer sheath of each sheath strand is greater than a diameter of a filament inside the outermost layer sheath of the sheath strand.

2. The steel cord for reinforcing a rubber article of claim 1 , wherein the plurality of sheath strands comprises 7 to 9 sheath strands.

3. The steel cord for reinforcing a rubber article of claim 1 , wherein the core strand has a 2+9 structure with the core of the core strand comprising two core filaments, nine sheath filaments being intertwined around the core of the core strand to form a sheath.

4. The steel cord for reinforcing a rubber article of claim 1 , wherein each sheath strand has a 3+7 structure or a 3+8 structure with a core of the sheath strand comprising three core filaments, seven or eight sheath filaments being intertwined around the core of the sheath strand to form a sheath.

5. The steel cord for reinforcing a rubber article of claim 1 , wherein each filament forming the core strand has an identical diameter.

6. The steel cord for reinforcing a rubber article of claim 1 , wherein a diameter of the steel cord is 4 mm or greater.

7. The steel cord for reinforcing a rubber article of claim 1 , wherein a diameter of the steel cord is less than 5 mm.

8. A pneumatic tire comprising the steel cord for reinforcing a rubber article of claim 1 .

Assignees

• Bridgestone Corp

Inventors

• Suzuki Hideto

Classifications

• D07B1/06

  Ropes or cables built-up from metal wires, e.g. of section wires around a hemp core · CPC title

• D07B2201/2051

  characterised by a value or range of the dimension given · CPC title

• D07B1/0626

  the reinforcing cords consisting of three core wires or filaments and at least one layer of outer wires or filaments, i.e. a 3+N configuration · CPC title

• D07B2201/2006

  characterised by a value or range of the dimension given · CPC title

• B60C9/00

  Reinforcements or ply arrangement of pneumatic tyres (inserts having reinforcing means B60C5/08; bead structure, e.g. turnup or overlap construction, B60C15/00) · CPC title