Two piece tire with improved tire tread belt and carcass

Abstract

A two-piece tire assembly has a removable tread belt 12 for installing about the circumference of a tire carcass 14 . The tread belt has a pair of lateral ends each axially extending beyond the inflated unloaded carcass 14 at the circumferential surface by a distance of at least 4% of the width as measured at the tread belt 12 and carcass 14 interface. The carcass 14 has an abrasion resistant rubber layer 82 at the tread belt interface. The tread belt 12 also has the abrasion resistance tread compound 82 at the carcass 14 interface.

What is claimed is:  
     
         1 . A two-piece tire assembly having a removable tread belt for installing about the circumference of a tire carcass and a tire carcass having an inflated and unloaded outer circumferential surface having an axial dimension no greater than the axial width of the removable tread belt, the two-piece tire assembly being characterized by: 
 the tread belt having a pair of lateral ends each axially extending beyond the inflated unloaded carcass at the outer circumferential surface of the carcass by a distance of at least 4% of carcass width as measured at the tread belt and carcass interface and wherein the tread belt width is at best equal to or wider than the loaded deflected carcass width as measured at the outer circumference of the carcass, each lateral end of the tread belt having a plurality of circumferentially extending cords in a first reinforcement layer and being radially inwardly flexible under load.    
     
     
         2 . The two-piece tire assembly of  claim 1  wherein the removable tread belt has a radially outer surface having a substantially flat tread arc radius R 1  between the lateral ends extending from 50% to 75% of the tread belt axial width and a smaller tread arc radius R 2  extending from the first tread arc R 1 , the tread outer surface having a sloping surface extending from a tangency to R 2  to a lateral end, the radial difference in the tread belt surface as measured at the centerline of the tread belt and each lateral end of the removable tread belt being about 3 to 8 percent of the outside diameter as measured by the centerline of the tread belt.  
     
     
         3 . The two-piece tire assembly of  claim 1  wherein the removable tread belt further comprises a belt reinforcing structure radially outward of the circumferentially extending cords in the first reinforcement layer.  
     
     
         4 . The two-piece tire assembly of  claim 3  wherein the belt reinforcing structure has a pair of cross-plies and a radially outer ply having cords oriented substantially 90 relative to the circumferentially extending cords in a first reinforcement layer.  
     
     
         5 . A two-piece tire assembly having a removable tread belt for installing about the circumference of a tire carcass and a tire carcass having an inflated and unloaded outer circumferential surface having an axial dimension no greater than the axial width of the removable tread belt, the two-piece tire assembly being characterized by: 
 the carcass having a radially outermost layer made of tread rubber, the tread rubber layer forming an abrasion resistance surface between the tread belt and the carcass.    
     
     
         6 . The two-piece tire assembly of  claim 5  wherein the tread belt has a rubber tread, the rubber tread material being the same as the tread rubber layer of the carcass.