TIRE CONSTRUCTION UTILIZING LOW-TWIST BODY PLY YARN WITH LOW TURN-UP ENDS

摘要

-20-ABSTRACT OF THE DISCLOSUREA pneumatic radial ply tire in which thebody ply is formed of a low twist yarn having be-tween three and six turns-per-inch. The body plyterminates in relatively low turn-up ends extendingalong the side walls a distance between 10% and 30%of the tire section height and out of the area ofcyclic stress and oscillation in the side walls ofthe tire. A relatively high, wide and hard beadfiller is located within a bead portion of the tireand has a height between 20% and 50% of the tiresection height with a width of between 15% and 35%of the bead filler height. The bead filler has ahardness of between 75 and 98 on the Shore A scale.The ply yarn preferably is polyester and the indi-vidual low twist strands are arranged in a parallelrelationship and is preferably free of transversecross strands known as wefts or picks. The combina-tion of low twist yarn, low turn-up body ply endsand bead filler size and hardness provides a tirehaving increased durability and uniformity at a lowercost.