Radial-ply tire

Abstract

To assure a positive camber thrust for a radial-ply tire including a belt of four or more plies on a carcass with rubber pads interposed therebetween, the width of the outermost belt ply is increased over the width of the adjacent belt ply and the ratio of the difference found by subtracting the tread width from the maximum belt ply width to the difference between the maximum tire width and the tread width is not less than 0.1 and not more than 0.4.

What is claimed is:  
     
         1 . A radial-ply tire comprising a belt consisting of four or more plies between a carcass and a tread with the interposition of pad rubber for isolating ends of said belt plies from said carcass, wherein the outermost belt ply width TBW is larger than the adjacent ply width NBW and the value of K given by the following equation is not less than 0.1 and not more than 0.4.  
       
         
           
             
               K 
               = 
               
                 
                   MBW 
                   - 
                   TW 
                 
                 
                   OW 
                   - 
                   TW 
                 
               
             
           
           
           
               
           
         
       
       where MBW is the maximum belt ply width, OW is the maximum tire width and TW is the tread width.  
     
     
         2 . The radial-ply tire of  claim 1  wherein the outermost belt ply width TBW is larger than the tread width TW.  
     
     
         3 . The radial-ply tire of  claim 1  wherein sidewalls of tire shoulders are elevated on the imaginary extension of the belt.