An agricultural tire includes a toroidal tire structure containing vulcanized rubber in an amount of about 90 percent or more by weight. The tire structure may have one or more performance enhancing features, including high strength plies. The high strength plies contain cords that are formed of yarns, including polyamide yarns, and have individual cord tensile strengths within a range of about 400 N to about 700 N. The performance enhancing features further include circumferential belt plies having cords at angles of about 74 degrees or more from an axial direction.

A vehicle tire comprises first and second bead cores spaced apart from each other, a first casing layer wrapped around the bead cores, a second casing layer wrapped around the bead cores, and a tread layer. The first casing layer has first edge sections that overlap with each other at a zenith of the tire and terminate at first edges on opposing sides of the zenith. The second casing layer has second edge sections that do not overlap with each other and that terminate at second edges that are each substantially aligned with one of the first edges. The first and second casing layers are each made of a single unidirectional ply that are in different directions to each other. The sidewall regions and the zenith comprise four plies of casing layers throughout the tire. The tire can further include first and second sidewall reinforcements (e.g., rubber strips) positioned in the first and second sidewall regions.

A pneumatic tire containing a polyester (e.g., polyethylene terephthalate or polyethylene naphthalate) derived from a non-fossil raw material. In a preferred embodiment, a polyester (e.g., polyethylene terephthalate or polyethylene naphthalate) in which a linear or cyclic moiety is produced using a raw material derived from a non-fossil raw material is used in the pneumatic tire. A pneumatic tire in which polyethylene terephthalate or polyethylene naphthalate produced using a raw material derived from a non-fossil raw material is used as a carcass material or a belt reinforcing material.

The present invention relates to a novel tire cord reinforcement made of ultra high modulus aramid fibers which has bi-elastic tensile properties. The cord includes at least two plies, and there is a spacing between the cord plies. Such a novel bi-elastic tire cord improves high speed durability and eliminates flatspotting when used as carcass reinforcement in pneumatic radial and bias tires.

In a pneumatic tire, a carcass layer mounted between bead portions includes composite cords made of polyethylene terephthalate fiber yarn having a fineness from 420-1200 dtex and an aromatic polyamide fiber yarn having a fineness from 520-1200 dtex, and a total fineness from 940-2400 dtex, and a twist coefficient from 1600 to 2400, the composite cords having an intermediate elongation from 2.0% to 4.5% with a load of 2.0 cN, having a dimensional stability index from 2.5% to 6.0% which is a sum of a dry heat shrinkage rate at 150 C. and the intermediate elongation with the load of 2.0 cN, and having a ratio of an initial elastic modulus at 100 C. within a load range from 0 N to 44 N with respect to an initial elastic modulus at 25 C. within a load range from 0 N to 44 N, the ratio being from 76% to 94%.

A pneumatic tire may include: a carcass; a belt reinforcing structure comprising a plurality of belt layers that include at least one spiral belt layer and at least one zigzag belt layer; and a tread comprising two or more main grooves extending circumferentially continuously around the pneumatic tire and defining a plurality of ribs that include two axially outermost ribs. At 10% to 100% of rated pressure and no load, each of the two axially outermost ribs may be raised (e.g., by a gap of 1 mm to 7 mm) in relation to a respective next nearest rib located axially inward of the respective axially outermost rib.

The reinforcing element (45) comprises an assembly (49) made up: of a multifilament strand made of aromatic polyamide or aromatic copolyamide (46) and of a multifilament strand made of polyester (48). The two strands (46, 48) are wound in a helix around one another, and the reinforcing element (45) is twist-balanced. The twist factor K of the reinforcing element (45) ranges from 5.5 to 6.5 where K is defined by the formula: K=(RTi.sup.1/2)/957 in which R is the twist of the reinforcing element (45) expressed in twists per metre and Ti is the sum of the counts of the multifilament strands of the reinforcing element (45) in tex.

A tire having reduced mass and low rolling resistance and a method of manufacture thereof achieves reduced weight by using thin layers of thermoplastic polyurethanes (TPU's) to heat seal the carcass, breaker, and tread layers of the tire to each other, rather than embedding the layers in conventional, relatively thicker and heavier layers of sulfur cured vulcanized carbon filled elastomers. Creep and spring-back of the thermoplastic polyurethanes during cure is avoided by maintaining the adhered layers under pressure until the assembly cools below its glass transition temperature. In embodiments, the heat sealing can be performed on the forming drum, and in some embodiments cool rollers are applied to the heat-sealed carcass so as to accelerate the cooling to below the glass transition temperature.

Provided are a pneumatic tire with improved dimensional stability, low loss property, and durability and a method of producing the same. In a pneumatic tire, a rubber-fiber composite is used in at least any of a carcass ply and a cap ply, the rubber-fiber composite containing: a fiber cord made of polyamide multifilament fibers having a glass transition temperature in a range of 150 C. to 200 C.; and a rubber, a layer made of a resorcin-formalin-latex adhesive is formed at an interface between the fiber cord and the rubber, and a thermal contraction stress at 177 C. of the fiber cord with the layer formed thereon is 0.01 cN/dtex to 0.2 cN/dtex.

In a pneumatic tire including a carcass layer mounted between a pair of bead portions and a belt reinforcing layer disposed on an outer circumferential side of the carcass layer, the carcass layer is formed of a carcass cord made of an organic fiber cord, an elongation at break of the carcass cord is set to 20% or more, an elongation under a load of 1.5 cN/dtex of the carcass cord in sidewall portions is set to from 5.0% to 8.0%, the belt reinforcing layer is formed of a cover cord made of an organic fiber cord, and a tensile strength of the cover cord per width of 50 mm at a 3.0% elongation is set to from 2.8 kN to 4.0 kN.