Sughrue, Rothwell, Mion, Zinn and Macpeak
Pneumatic tires for heavy vehicles
 A radial tire provided with a tread pattern suitable for travel on paved roads at a high speed is disclosed. The tread pattern is of a block-rib type which is constructed to satisfy the following conditions, i.e. PA1 (1) W.sub.1 =(5-9%) TW PA1 (2) W.sub.2 =(0.5-2.5%) TW PA1 (3) 60% BW.gtoreq.A and A.gtoreq.20% TW PA1 (4) B.sub.2 =(1.0-2.0) B.sub.1 where W.sub.1 is a width of a wide circumferential groove, TW is a tread width, W.sub.2 is a width of a narrow circumferential groove, BW is an effective width of a belt, A is a width of a tread center portion, B.sub.1 is a tread side portion facing the tread center portion and B.sub.2 is a tread side portion facing two shoulder portions. 
Bridgestone Tire Company Limited
Y B
Y10S B61C
additional inventional
Shigeo Shigeo Toshiyuki
Watanabe Makino Sogi