Pneumatic tires with cable bead core
AssigneeBridgestone Corporation
InventorYoshinobu Shoyama
Life of this patent
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Abstract
A pneumatic tire comprises a bead core formed by laminating three or more sheath layers of spirally twisted sheath filaments around a thick core wire and making reverse the twisting direction of the sheath filament in these sheath layers every the sheath layer, in which the number of twisting pitches in the sheath filament of a second sheath layer viewed from the outermost side is made smaller than that in sheath filament of a sheath layer located inward from the second sheath layer.
Claims4
In a pneumatic tire comprising a bead portion provided with a bead core formed by laminating three or more sheath layers, each of which layers being constituted by substantially spirally twisting a plurality of fine sheath filaments, on a single thick core wire and making reverse twisting directions of the sheath filaments in the sheath layers every the sheath layer, an improvement wherein the number of twisting pitches in a sheath filament of a second sheath layer viewed from an outermost side of the sheath layers is made smaller than that in a sheath filament of a sheath layer located inward from the second sheath layer.
Dependencies are inferred from the claim text.