Pneumatic tire

Abstract

A pneumatic radial tire has a pair of opposing bead portions 14, each bead portion 14 has a bead core 23 and a bead apex 24; at least one carcass reinforcing ply 12 having radially oriented steel cords 22, the at least one carcass reinforcing ply 12 has a main portion 18 and two turnups 20, one turnup 20 extending from each end of the main portion 18 and having a terminal end 21, the carcass reinforcing ply main portion 18 extends between the opposing bead cores 23 and turnups 20 are located axially outward of the bead core 23 and a portion of the bead apex 24; and two pairs of steel cord reinforced chippers, one pair adjacent each turnup, each pair having one inner chipper 40 being adjacent and on an axially inner side of the turnup 20 and one outer chipper 30 being adjacent on an axially outer side of the turnup 20, the inner and outer chippers 40, 30 being adjacent the turnup 20 each have a terminal end 41, 31 extending radially outward of the terminal end 21 of the turnup 20.

What is claimed is: 
     
         1 . A pneumatic radial tire, the tire comprising:
 a pair of opposing bead portions, each bead portion has a bead core and a bead apex   at least one carcass reinforcing ply having radially oriented steel cords, the at least one carcass reinforcing ply has a main portion and two turnups, one turnup extending from each end of the main portion and having a terminal end, the carcass reinforcing ply main portion extends between the opposing bead cores and turnups are located axially outward of the bead core and a portion of the bead apex; and   two pairs of polyamide monofilament cord reinforced chippers, one pair adjacent each turnup, each pair having one inner chipper being adjacent and on an axially inner side of the turnup and one outer chipper being adjacent on an axially outer side of the turnup, the inner and outer chippers adjacent the turnup each have a terminal end extending radially outward of the terminal end of the turnup.   
     
     
         2 . The pneumatic radial tire of  claim 1  wherein the adjacent inner chipper has the steel cords oriented on a bias angle in relative to a radial plane of the tire and the adjacent outer chipper has the steel cords oriented in a bias angle opposite in direction relative to the inner chipper. 
     
     
         3 . The pneumatic radial tire of  claim 2  wherein the steel cords of the chippers are oriented on a bias angle in the range of 25 to 85 degrees. 
     
     
         4 . The pneumatic radial tire of  claim 3  wherein the steel cords of the chippers are oriented at equal but oppositely oriented bias angles. 
     
     
         5 . The pneumatic radial tire of  claim 1  wherein each chipper has the steel cords arranged substantially parallel in the range of 8 to 15 ends per inch (3 to 6 ends per cm). 
     
     
         6 . The pneumatic radial tire of  claim 1  further comprises a second axially inner chipper having steel cords lying adjacent to and axially inward of the inner chipper. 
     
     
         7 . The pneumatic radial tire of  claim 1  further comprises:
 a belt reinforcement structure having three or more steel cord reinforced belt layers disposed radially outward of the at least one carcass reinforcing ply; and 
 a tread radially outward of the belt reinforcing structure; and 
 a top belt layer covering the at least three or more steel cord belt layers, the top belt having cords of nylon or polyamide.