Tread for a giant pneumatic radial tire

Abstract

The tread of a giant pneumatic radial tire for use on heavy-duty road vehicles is divided by two wide circumferential grooves into three wide circumferential ribs. The wide ribs are substantially free of grooves therein interrupting their circumferential continuity and of wide circumferential grooves.

I claim: 
     
       1. A giant pneumatic tire for use on heavy-duty road vehicles having a radial carcass and a tread, said tread having a pair of wide, substantially V-shaped grooves in cross-section extending circumferentially of said tread, said grooves being substantially equally spaced on opposite sides of the median plane of said tire and spaced apart between about one-fifth and one-half of the width of said tread and each said grooves having a width at the surface of said tread substantially 3% to 6% of the width of said tread, said grooves dividing said tread into three circumferential wide ribs, .Iadd.each of .Iaddend.said ribs being substantially free of grooves therein interrupting the circumferential continuity .Iadd.over substantially the entire width .Iaddend.thereof and of wide circumferential grooves.Iadd., none of said wide ribs having more than two circumferentially continuous narrower grooves of substantial depth.Iaddend.. 
     
     
       2. The tire set forth in claim 1 in which said wide grooves are spaced apart about one-third the width of said tread and said wide ribs are of substantially equal width. 
     
     
       3. The tire set forth in claim 1 comprising a plurality of narrow grooves in said tread extending circumferentially thereof and dividing two of said wide ribs into a plurality of narrower circumferential ribs of substantially equal width between said wide grooves and the edges of said tread. 
     
     
       4. The tire set forth in claim 3 in which said narrow grooves have a width at the surface of said tread of about 0.5% to 1% of the width of said tread. 
     
     
       5. The tire set forth in claim 1 comprising a plurality of narrow grooves extending circumferentially of said tire between said wide grooves and between the edges of said tread and said wide grooves, said wide and narrow grooves being spaced apart substantially equal distances and said wide ribs being divided into circumferentially extending narrower ribs of substantially equal width. 
     
     
       6. The tire set forth in claim 3 in which said wide and narrow grooves are substantially parallel and of wavy configuration circumferentially of said tire.