Patent Description:
For purposes of this application, the phrase "for a high speed under a heavy load" shall be understood to mean operation of the tire under the conditions that the load subjected to the tire is remarkably high and that a centrifugal force acting on the ground contact zone of the tire, when the tire rotates at a high speed, becomes significantly large and must be taken into consideration. For example, a conventional tire may operate under especially severe conditions as in the case of aircraft and/or similar high speed transport tires subjected to a heavy load. The tire must be suitably sturdy/robust for such a severe condition.

One conventional tire, used under the above-mentioned conditions, may include a side wall portion, a tread portion, a hump portion having a particularly large thickness, and a carcass reinforcing ply. The entire carcass reinforcing ply may extend from one of bead cores to the other bead core. The carcass reinforcing ply may be provided at its outermost layer with a breaker for the purpose of improving cut and/or puncture resistance of the tire.

In such a conventional tire, the carcass reinforcing ply may include plies which are substantially the same in number from the center of the tread portion through the hump portion to the side wall portion and which are uniform in thickness distribution. This thickness distribution may be substantially the same even when the carcass reinforcing ply is provided at its outermost layer with the cut/puncture resistant breaker.

The cut/puncture resistant breaker is suitable to mitigate a decrease of the crown radius of the tire induced by high-speed rotation and corresponding centrifugal force. Such a reduction in a decrease in crown radius allows it to improve the load-bearing-ability of the tire for high speed under a heavy load.

<CIT> describes a tire in accordance with the preamble of claim <NUM>.

<CIT>, <CIT> and <CIT>, which has been published only after the priority date of this application, each describe a tire comprising a tread, a carcass having at least one ply wound about a pair of bead cores, a crown reinforcement or belt structure, and at least one breaker layer radially inside the tread, wherein the at least one breaker layer is formed of monofilaments inclined at an angle in a range of from <NUM> degrees to +/- <NUM> degrees relative to the equatorial plane of the tire.

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

A first preferred tire for use under heavy loads and high speeds, in accordance with the present invention, includes a tread, a crown reinforcement or belt structure, a carcass reinforcement with at least one ply wound about a pair of bead cores, and a cut/puncture resistant breaker layer disposed radially adjacent the crown reinforcement or belt structure and radially inside the tread. The cut/puncture resistant breaker layer is formed of monofilaments inclined at from <NUM> degrees to <NUM> degrees (or -<NUM> degrees) relative to the equatorial plane of the tire.

According to a preferred aspect of the invention, the breaker layer is disposed adjacent a radially outer surface of the crown reinforcement or belt structure.

According to another preferred aspect of the invention, the breaker layer is disposed adjacent a radially outer surface of an overlay structure of the crown reinforcement or belt structure.

According to yet another preferred aspect of the invention, the breaker layer is disposed adjacent a radially inner surface of an overlay structure of the crown reinforcement or belt structure.

According to still another preferred aspect of the invention, the breaker layer is disposed radially between a first belt of the belt structure or the crown reinforcement and a second belt of the belt structure or the crown reinforcement.

According to yet another preferred aspect of the invention, the breaker layer is disposed radially between the belt structure or the crown reinforcement and an overlay structure of the crown reinforcement or belt structure.

According to still another preferred aspect of the invention, the breaker layer is disposed radially between an undertread of the tread and the crown reinforcement or belt structure.

According to yet another preferred aspect of the invention, the breaker layer is disposed radially adjacent a radially outer surface of the carcass reinforcement.

According to still another preferred aspect of the invention, each of the monofilaments are inclined between <NUM> degrees and <NUM> degrees relative to the equatorial plane of the tire.

According to yet another preferred aspect of the invention, each of a first plurality of monofilaments are parallel to each of a remaining first plurality of monofilaments.

According to still another preferred aspect of the invention, each of a second plurality of monofilaments are parallel to each of a remaining second plurality of monofilaments.

According to the invention, each of the first plurality of monofilaments have a first angle of inclination relative to the equatorial plane of the tire and each of the second plurality of monofilaments have a second angle of inclination relative to the equatorial plane of the tire, the first angle being equal and opposite the second angle.

According to still another preferred aspect of the invention, the breaker layer is formed by spirally winding a single monofilament around a radially outer surface of the crown reinforcement or belt structure.

According to yet another preferred aspect of the invention, the breaker layer is formed by spirally winding a single monofilament radially between a first belt layer of the belt structure or the crown reinforcement and a second belt layer of the belt structure or the crown reinforcement.

According to still another preferred aspect of the invention, the monofilaments are formed from textile fibers.

A second preferred tire for use under heavy loads and high speeds, in accordance with the present invention, includes a tread, a crown reinforcement, a carcass reinforcement with at least one ply wound a pair of bead cores, and a cut/puncture resistant breaker layer disposed radially adjacent the crown reinforcement or belt structure and radially inside the tread. The cut/puncture resistant breaker layer is formed of parallel monofilaments inclined at <NUM> degrees relative to an equatorial plane of the tire.

The present invention will be described by way of example and with reference to the accompanying drawings, in which:.

<FIG> illustrates an aircraft tire <NUM> as a preferred embodiment of the present invention. The tire <NUM> may has a tread <NUM> with sidewall portions <NUM> connected to, and extending from, the lateral edges of the tread <NUM>. At the radially inner ends of each sidewall <NUM> is a bead portion <NUM>. Each bead portion <NUM> has a bead core <NUM>, an apex <NUM> extending radially outward from the bead core <NUM>, and preferably at least one chafer layer <NUM> reinforced with cords <NUM> to reduce rim chafing of the tire <NUM>. A carcass reinforcing ply structure <NUM> extends from one bead portion <NUM> to the opposing bead portion <NUM>, preferably with turnup portions as shown. In greater detail, the tire <NUM> of <FIG> is illustrated by the diagrammatic cross-section views of <FIG> and <FIG>.

With reference to <FIG> and <FIG>, the carcass reinforcement <NUM> is preferably formed of six plies 2A to 2F of radial textile cords <NUM>. Among these six plies, four axially inner plies 2A, 2B, 2C and 2D may be wound around each circular bead core <NUM>. These four plies may extend from the inside to the outside of the tire <NUM> in order to form turn-ups 20A, 20B, 20C and 20D. The carcass reinforcement <NUM> is radially outward of the innerliner <NUM> of tire <NUM>.

Outward of the bead cores <NUM> may be a strip or filler <NUM> of elastomeric material having a substantially triangular shape extending to an apex A radially furthest from the rotation axis of the tire <NUM> and located a distance D from a reference line XX'. As shown in <FIG>, the reference line may also be parallel to the axis of rotation and pass through the geometric center O of the circle circumscribed on the cross section of the bead core <NUM>.

A flipper <NUM>, which can be formed of radial textile cords <NUM> similar to those of plies <NUM>, may be located with an inner end L, slightly above the height Bh of the bead core <NUM> and an outer end LE may also be slightly above the bead core <NUM> as measured from line YY'. The ends LI, LE may satisfy a relationship wherein Bh < Ll, and LE < <NUM>. 7D, as measured from the nominal bead diameter NBD. To minimize the space occupied by the flipper <NUM>, the cords <NUM> may be made of a diameter smaller than the ply cords <NUM>.

The carcass may further have two carcass plies 2E and 2F herein called outer plies. These outer plies 2E, 2F may cover the turn-ups 20A through 20D of the inner plies 2A through 2D. The outer plies 2E and 2F may be wound around the bead core <NUM> over a portion of the circular arc radially outside of the center of bead core <NUM>. The ply ends 20E and 20F may thus be disposed axially inward of the lowest portion of the bead core <NUM>. The ends 20E and 20F may effectively be pinched between the bead core <NUM> and the rim seat thereby securely anchoring the outer plies 2E, 2F.

The tire bead may have an outer chipper <NUM> of textile cords <NUM> wrapped around the ends 20E and 20F assuring protection of the carcass plies against damage during mounting. Radially below the chipper <NUM> may be a chafer <NUM> having a rubber gauge in the range between <NUM> and <NUM>.

Axially outward of the chafer <NUM> and the plies 20E and 20F may be an elongated strip <NUM> of elastomeric material extending from radially inward of the bead <NUM> adjacent the chafer <NUM> to a radial location at, or slightly above, the turn-up 20B, but below the turn-up 20D. As shown, this strip <NUM> may be interposed between the sidewall rubber <NUM> and the outer ply 20F. At a location almost equal to the radial height D of the apex A, the strip <NUM> preferably has have a maximum thickness t of <NUM>.

Referring back to <FIG>, radially outward of the carcass <NUM> is a crown reinforcement or belt structure <NUM>. The belt structure <NUM> preferably has at least belt two ply layers of cords <NUM> inclined at an angle between <NUM> degrees to <NUM> degrees. The cords <NUM> in each belt ply layer are preferably parallel to each other and crossed relative to the cords <NUM> in the adjacent belt ply layer. The radial carcass reinforcement is radially surmounted by the crown reinforcement, or belt structure <NUM>, and is preferably formed of a plurality of textile layers of reinforcement elements or cords <NUM> which are inclined relative to the circumferential direction by a predetermined angle. So as to avoid free ends of crown/belt plies, the layers are preferably laid out by winding around a cylindrical or rounded form or a carcass reinforcement blank a strip of at least one textile reinforcement element or cord <NUM> from one axial edge of the layer to the other thereby forming the desired angle with the equatorial plane of the tire <NUM>.

In a preferred embodiment of the invention, there is an overlay ply <NUM> radially outward of the belt structure <NUM>. The overlay ply <NUM> is shown in <FIG> radially outward of the belt plies <NUM>, but such an overlay ply <NUM> may also be located radially inward of the belt plies <NUM> or between two of the belt plies <NUM>. The overlay ply <NUM> is preferably formed of cords <NUM> inclined at between <NUM> degrees and <NUM> degrees relative to the equatorial plane of the tire <NUM>. The inclination angle of the cords <NUM> may be partially dependent upon the formation and application method of the overlay ply <NUM>. The overlay ply <NUM> may be spirally wound onto a tire building machine - preferably with spiral winding of a single elastomeric encased cord or an elastomeric ribbon of multiple cords having a width between <NUM> and <NUM> and a cord density in a range between <NUM> ends per inch (<NUM> ends per cm) and <NUM> ends per inch (<NUM> ends per cm). The overlay ply <NUM> may also be a cut ply of parallel cords <NUM>. A spirally wound layer may have a greater inclination angle relative to the equatorial plane than a cut ply of parallel cords <NUM>. Each of the elements described above may employ the textile cords <NUM>, <NUM>, <NUM>, <NUM>, and/or <NUM> including the carcass plies <NUM>, the belt plies <NUM> or strips, the chafer <NUM>, the flipper <NUM>, and/or the overlay <NUM>.

In accordance with the present invention, one of more preferably cut/puncture resistant breaker layers <NUM> may be disposed adjacent a radially outer surface of the overlay <NUM> (<FIG> & <FIG>) and radially inside the tread <NUM>, adjacent a radially outer surface of the belt structure <NUM> radially inside the overlay <NUM>, and/or radially between layers of the overlay <NUM> and/or belt structure <NUM>.

The one or more breaker layer(s) <NUM> are formed of monofilaments <NUM> preferably inclined between <NUM> degrees and <NUM> degrees relative to the equatorial plane of the tire <NUM>. The inclination angle of the cords <NUM> may be partially dependent upon the formation and application method of the breaker layer(s) <NUM>.

The breaker layer(s) <NUM> are preferably spirally wound onto a tire building machine - with spiral winding of a single elastomeric encased monofilament <NUM> or an elastomeric ribbon of multiple monofilaments <NUM> preferably having a width between <NUM> and <NUM> and preferably having a density in a range from <NUM> ends per inch (<NUM> ends per cm) to <NUM> ends per inch (<NUM> ends per cm).

The breaker layer(s) <NUM> may also be a cut ply of parallel cords <NUM> (<FIG>).

A spirally wound layer preferably has a greater inclination angle relative to the equatorial plane than a cut ply <NUM> of parallel cords <NUM>.

The breaker layer(s) <NUM> preferably employ textile and/or steel monofilaments <NUM>.

Claim 1:
A tire comprising a tread (<NUM>), a carcass having at least one ply (2A-2F), preferably a plurality of plies (2A-2F) such as three to six carcass plies, wound about a pair of bead cores (<NUM>), and a crown reinforcement or belt structure (<NUM>), and wherein the tire (<NUM>) further comprises at least one breaker layer (<NUM>) radially inside the tread (<NUM>), wherein the at least one breaker layer (<NUM>) is formed of monofilaments (<NUM>) inclined at an angle in a range of from <NUM> degrees to +/- <NUM> degrees relative to the equatorial plane (CL) of the tire (<NUM>) and wherein the breaker layer (<NUM>) comprises a first plurality of monofilaments (<NUM>) having a first angle of inclination relative to the equatorial plane (CL) of the tire (<NUM>) and a second plurality of monofilaments (<NUM>) having a second angle of inclination relative to the equatorial plane (CL) of the tire (<NUM>), the first angle being equal and opposite the second angle, characterized in that the tire (<NUM>) further comprises at least one overlay ply (<NUM>), the at least one overlay ply (<NUM>) comprising cords (<NUM>) inclined at an angle in a range of from +/-<NUM> degree to +/-<NUM> degrees relative to the equatorial plane (CL) of the tire (<NUM>).