Patent Description:
Fabric belt assemblies and other fabric structures for tires are known. In one conventional assembly, a folded ply may be reinforced with cords of high modulus material and may have an overall width at least equal to that of the tread portion. Each of its lateral sides may be folded back, in a radially outward direction, around two unfolded single cut plies. The reinforcing cords of the folded ply may form an angle between <NUM> and <NUM> degrees relative to the with respect to the equatorial plane of the tire with those of the two single cut plies forming equal and opposed angles with respect to the equatorial plane of the tire.

Because of material limitations, conventional tire constructions have tended to be robust (e. , heavy and many components, etc.). Such constructions may tend to have a high rolling resistance, which lowers fuel economy; and the bulk of the construction may have a tendency to limit handling response, as well as increasing material cost. It has been a continuing goal to identify lightweight and high strength materials, and to find suitable uses for such materials in tires, such that the weight of tires may be reduced while other properties are maintained.

Conventional aramid reinforcement material has shown fatigue resistance. This property made the material suitable for application of a relatively low twist to the cord, which made it possible to maintain durability and elongation characteristics in a lower density material. One conventional belt assembly has shown improved handling properties when reinforcement cords were reduced to <NUM> dTex from <NUM> dTex. One conventional overlay structure may be reinforced with aramid cords having a twist level between <NUM> TPI (TPI = "turns per <NUM>") and <NUM> TPI.

One conventional belt structure may be reinforced with <NUM> to <NUM> dTex aramid cords, with a measured toughness of <NUM> MPa to <NUM> MPa, an initial modulus <NUM>,<NUM> MPa to <NUM>,<NUM> MPa, a tenacity of <NUM> cN/Tex to <NUM> cN/Tex, and a dynamic flex fatigue retained break strength of <NUM>% to <NUM>%. These belts may be reinforced with reinforcement cords extending parallel to one another and making an angle of <NUM>° to <NUM>° with respect to the equatorial plane (EP) of the tire. The belt assembly may comprise a folded belt with folded portions on each lateral side folded radially over a cut belt. The axially outer portions of the folded belt may be folded in a radially outward direction and disposed radially outward of the cut belt.

Another conventional tire may have an overlay structure disposed radially outward from the belt assembly. Helical convolutions of a ribbon may be wound axially across two single cut plies such that the convolutions are in abutting contact with each other. The ribbon may be reinforced with cords of textile material.

<CIT> discloses a wick woven chafer fabric for automotive radial tires, having a monofilament fill yarn and a large denier textured multifilament warp yarn. It is described therein that the filling yarns if multifilament, and particularly textured, tend to flatten out so that the filling yarn shall be monofilament to avoid flattening of the filling yarn.

<CIT> discloses a tire with finishing strips having fabrics which comprise interwoven warp and weft elements. In embodiments, the weft elements shall be impermeable to the passage of air and are preferably single or monofilaments. The warp elements may comprise a plurality of filaments.

The invention relates to a fabric layer in accordance with claim <NUM> and to a tire in accordance with claim <NUM>.

According to a preferred aspect of the invention, the fabric layer further includes flat textured weft stitches for mitigating possible cracks.

According to a preferred aspect of the invention, each of the warp cords is a flat monofilament.

According to a preferred aspect of the invention, each of the warp cords is a relatively thin monofilament.

According to a preferred aspect of the invention, each of the warp cords is an oblong monofilament.

According to a preferred aspect of the invention, each of the warp cords is a cylindrical monofilament.

According to a preferred aspect of the invention, each of the weft cords absorbs an adhesive dip.

According to a preferred aspect of the invention, a lateral stiffness of the fabric layer prevents relative movement between each of the warp cords.

According to a preferred aspect of the invention, a lateral stiffness of the fabric layer prevents the warps cords from being moved by an external penetrating sharp object.

According to a preferred aspect of the invention, the fabric layer maintains the warp cords at a constant lateral spacing.

According to a preferred aspect of the invention, each flat weft cord has a ratio of the thickness of the weft cord as measured in a direction perpendicular to the fabric layer to the width of the weft cord as measured in a direction perpendicular to the length of the weft cord in a range of less than <NUM> or less than <NUM>.

According to a preferred aspect of the invention, the flat warp cord has a ratio of the thickness of the warp cord as measured in a direction perpendicular to the fabric layer to the width of the warp cord as measured in a direction perpendicular to the length of the warp cord in a range of less than <NUM>, preferably less than <NUM> or less than <NUM>.

According to a preferred aspect of the invention, the flat weft stitches have a ratio of the thickness of the weft stiches as measured in a direction perpendicular to the fabric layer to the width of the weft stitches as measured in a direction perpendicular to the length of the weft stitches in a range of less than <NUM>, preferably less than <NUM> or less than <NUM>.

With reference to <FIG>, there is represented a tire <NUM>, pneumatic or non-pneumatic, for use with the present invention. The tire <NUM> preferably has a pair of substantially inextensible bead cores <NUM>, <NUM> axially spaced apart with one or two carcass plies <NUM>, <NUM> (or more) extending between the bead cores <NUM>, <NUM>. The carcass plies <NUM>, <NUM> may be folded axially and radially outward about each of the bead cores <NUM>, <NUM> and be reinforced by cords substantially parallel to each other in the same ply at an angle of <NUM>° to <NUM>° with respect to the equatorial plane (EP) of the tire <NUM>. Cords belonging to adjacent carcass plies <NUM>, <NUM> preferably have opposite angles crossing each other. The cords of the carcass plies <NUM>, <NUM> may be any suitable material, such as steel, nylon, rayon, aramid, and/or polyester. The tire <NUM> may have carcass plies <NUM>,<NUM> of side-by-side polyester or rayon cables and a crown area <NUM> reinforced by a belt assembly <NUM> located radially inward of the tire tread <NUM>. The tire <NUM> preferably has an aspect ratio between <NUM> and <NUM>.

The tire <NUM> may include a belt structure <NUM> with an essentially rigid folded belt <NUM> and a cut belt <NUM> disposed radially outward of the folded belt. Both belts <NUM>, <NUM> may be reinforced with, for example, aramid cables or yarns. The belts <NUM>, <NUM> may have identical or different constructions. Such cords may be treated (coated) with one or more layers of adhesive in a process known as dipping. The modulus of a treated cord may be a function of the twist of the different yarns used in the cord, the cord twist, and the manner that the cord is subjected to the dipping operation.

Cords of the folded belt <NUM> are preferably substantially parallel to each other and make an angle of <NUM>° to <NUM>° with respect to the equatorial plane (EP) of the tire <NUM>. The axially outer portions of the folded belt <NUM> may be folded back on both lateral sides in a radially outward direction over axial edges of the cut belt <NUM> with the folded portions <NUM>, <NUM> being symmetrical with respect to the equatorial plane (EP). The folded portions <NUM>, <NUM> may each have a transverse width between <NUM>% and <NUM>%, or <NUM>% and <NUM>% of the tread width (TW).

As shown in <FIG>, another example tire 10a, for use with the present invention, includes one carcass ply 13a wrapped around beads 11a, 12a. The belt structure <NUM> preferably includes belts <NUM>, <NUM> reinforced with aramid cords and overlays <NUM>, <NUM> disposed radially outward of the belts <NUM>, <NUM>. The belts <NUM>, <NUM> may have identical or different constructions. The overlays <NUM>, <NUM> may be single sheets of overlay material, a cut overlay (e.g., reinforcement cords in the overlay discontinuous at random locations throughout the tire), and/or a spiral overlay. The reinforcing cords in the overlay <NUM>, <NUM> may comprise nylon, polyester, polyamine, aramid, and/or any other suitable overlay reinforcement material.

As shown in <FIG>, in accordance with the present invention, structures of the belts <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, overlays <NUM>, <NUM>, carcass <NUM>, <NUM>, reinforcement for the crown area <NUM>, chippers, flippers, toe guards, protective layers, and/or any other suitable plies/layers of the tire <NUM> may include a woven fabric layer <NUM> (which may also be called woven fabric structure <NUM>) with warp cords <NUM> and weft cords <NUM>.

Conventionally, weft yarns, filaments, threads, cables, fibers, and/or cords (hereinafter generally "cords") <NUM> of a fabric <NUM> may only function to provide integrity to the fabric for handling before installation in, for example a tire <NUM> (<FIG>).

The warp cords <NUM> are preferably each relatively smooth, flat or thin or oblong or cylindrical, monofilament.

As shown in <FIG>, when adhered to rubber, separations at a rubber-monofilament interface may propagate along the length of a monofilament due to the smooth surface and, in a tire <NUM>, may cause "tread throws" if the monofilament is used as a protective layer or other failure of structural integrity.

According to a preferred embodiment of the present invention, the weft cords <NUM> include flat textured multifilament cords as each weft cord <NUM> extends transverse to the monofilament warp cords <NUM>. Such a construction may help to prevent or stop crack propagation along the length of the warp cords <NUM>, function as a stitch for securing both sides of a possible crack, increase fabric surface area to increase adhesion between rubber and the fabric <NUM>. The increased wider surface area of the flat textured multifilament wefts cords <NUM> may retain more adhesive dip and increase adhesion strength via increased adhesion interfacial area. Further, dip may increasingly penetrate the textured multifilament weft cords <NUM> thereby enhancing the structural integrity and adhesive bond of the overall fabric <NUM>. Consequently, flat textured weft/pick cords <NUM> may not increase fabric gauge/thickness significantly.

Additionally, flat textured weft stitches <NUM> around possible cracks <NUM>, which may propagate along the length of flat monofilament warp cords <NUM>, may further support structural integrity of the fabric <NUM> (<FIG>). The flat textured weft cords <NUM> may increase lateral stiffness of the fabric <NUM> and/or a fabric/rubber treatment and/or a composite of both. As discussed above, textured weft cords <NUM> may have a larger surface area and thus absorb more dip than smaller gauge twisted weft cords. This large surface area, along with more dip, may create a stiff weft cord <NUM> that may further secure adjacent flat monofilament warp cords <NUM>.

Claim 1:
A fabric layer for a tire, the fabric layer (<NUM>) comprising a plurality of warp cords (<NUM>), each warp cord (<NUM>) being a monofilament, and a plurality of weft cords (<NUM>) extending transversely over and under the warp cords (<NUM>), each weft cord (<NUM>) being a flat multifilament cord, wherein
the flat weft cord (<NUM>) has a ratio of the thickness of the weft cord (<NUM>) as measured in a direction perpendicular to the fabric layer (<NUM>) to the width of the weft cord (<NUM>) as measured in a direction perpendicular to the length of the weft cord in a range of less than <NUM>.