Patent Description:
One problem encountered in the use of pneumatic tires, and particularly for relatively large tires such as those referred to as truck and bus radial tires which are utilized on eighteen-wheeler trucks and on buses, is the entrapment of stones in the relatively large tread grooves of the tires. If a stone is trapped in the tread groove against the bottom of the tread groove, repeated impacting of the stone against the ground surface may cause the stone to cut into or drill into the bottom of the tread groove thus eventually reaching the structural members of the tire and degrading the strength and life of the tire. Documents <CIT> and <CIT> disclose tires according to the state of the art.

There is a continuing need for improvement in the design and construction of such stone rejectors.

In a first set of embodiments, a pneumatic tire having a tread portion is described. The tread portion includes a generally circumferentially extending groove defined therein. The groove has a groove cross-section defined by a groove bottom, a first groove sidewall, and a second groove sidewall. The second groove sidewall is opposite and substantially parallel to the first groove sidewall. The groove has a groove width defined between the first groove sidewall and the second groove sidewall. A plurality of stone rejecters extend between the first groove sidewall and the second groove sidewall. Each stone rejector in the plurality of stone rejectors is circumferentially spaced from an adjacent stone rejector. Each stone rejector includes a raised platform and a protrusion. The raised platform extends axially from the first groove sidewall to the second groove sidewall. The protrusion extends from a top surface of the raised platform.

In a second set of embodiments, a tread portion is described. The tread portion includes a generally circumferentially extending groove defined therein. The groove has a groove cross-section defined by a groove bottom, a first groove sidewall, and a second groove sidewall. The second groove sidewall is opposite and substantially parallel to the first groove sidewall. The groove has a groove width defined between the first groove sidewall and the second groove sidewall. A plurality of stone rejectors extend between the first groove sidewall and the second groove sidewall. Each stone rejector in the plurality of stone rejectors is circumferentially spaced from an adjacent stone rejector. Each stone rejector includes a raised platform and a protrusion. The raised platform extends axially from the first groove sidewall to the second groove sidewall. The protrusion extends from a top surface of the raised platform.

The foregoing and other features of the present invention will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several implementations in accordance with the invention and are therefore, not to be considered limiting of its scope, the invention will be described with additional specificity and detail through use of the accompanying drawings.

Reference is made to the accompanying drawings throughout the following detailed description. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative implementations described in the detailed description, drawings are not meant to be limiting. Other implementations may be utilized, and other changes may be made, without departing from the scope of the claims.

Embodiments described herein relate generally to a plurality of grooves along a tread portion of a pneumatic tire that include a plurality of stone rejectors, each with a stone rejector rib and a stone rejector protrusion formed thereupon. The stone rejectors are configured to impede and eject debris (e.g., stones, concrete, rocks, etc.) and foreign objects from entering the grooves early in the tire's life. Absent the plurality of stone rejector ribs and stone rejector protrusions along the grooves, the depth of the deep grooves of the tread portion allows for the stones to be held or trapped by the compression of the rubber in the sides or walls of the ribs formed by adjacent grooves. Eventually the stones are forced against the bottom of the groove by pressure of the load on the tire and road surfaces, thereby wearing or puncturing the tire.

Referring to <FIG>, a schematic cross-section view is shown of a pneumatic tire <NUM>. The tire <NUM> has first and second sidewalls <NUM> and <NUM>. A circumferential tread area or tread portion <NUM> extends between the sidewalls. The term "circumferential" refers to the direction extending along the perimeter of the surface of the annular tread perpendicular to the axial direction, where the axial direction is the direction that is parallel to the axis of rotation of the tire <NUM>, and the radial direction is perpendicular to the axis of rotation of a tire <NUM>. First beads <NUM> and the second beads <NUM> are located in the first bead portions <NUM> and the second bead portions <NUM> of the first sidewall <NUM> and second sidewall <NUM>, respectively. As used herein, the term "bead" or "bead core" refers to that part of a tire <NUM> comprising an annular tensile member, the bead core, wrapped by ply cords (e.g., continuous layer of rubber coated parallel cords) and shaped, with or without other reinforcement elements to fit a designed tire rim.

A carcass <NUM> including one or more body plies <NUM> and <NUM> extends through the tread portion <NUM>, down through the sidewalls <NUM> and <NUM>, and wraps around the beads <NUM> and <NUM> terminating in turn-up ends <NUM>. As used herein, the term "carcass" <NUM> refers to the tire structure apart from the belt structure, tread, undertread, and sidewall rubber but including the beads, (carcass plies are wrapped around the beads). One or more circumferentially extending reinforcing belts, which may be generally referred to as a belt package <NUM>, are placed in the tread portion <NUM> radially outside of the carcass <NUM>.

The tread portion <NUM> includes a radially outer ground contacting surface <NUM> having a plurality of tread grooves <NUM>, shown in <FIG> as a first tread groove <NUM>, a second tread groove <NUM>, a third tread groove <NUM>, and a fourth tread groove <NUM>. Each tread groove in the plurality of tread grooves <NUM> includes a plurality of stone rejectors <NUM>, each with a raised platform <NUM> (e.g., stone rejector ribs) and a protrusion <NUM> (e.g., stone rejector protrusions). As discussed in greater detail below, each raised platform <NUM> in the plurality of raised platforms <NUM> includes a protrusion <NUM> and each raised platform <NUM> extends axially along the tread groove and spaced radially away from an adjacent raised platform. In some embodiments, the plurality of grooves <NUM> may have a groove depth <NUM> in unworn condition. The plurality of raised platforms <NUM> with the plurality of protrusions <NUM> may be implemented in a wide variety of groove widths and depth dimensions in the tread portion <NUM>. For example, a tread groove from the plurality of tread grooves <NUM> located at or near the center of the tread portion <NUM> may be wider or narrower, deeper or shallower than the grooves located at or near the outer edges (e.g., proximate to the sidewalls <NUM>, <NUM>) of the tire tread portion <NUM>.

As shown in <FIG> and <FIG>, each tread groove in the plurality of tread grooves <NUM> includes a groove bottom <NUM>, a first groove sidewall <NUM>, and a second groove sidewall <NUM>. Each groove in the plurality of grooves <NUM> has a groove width <NUM> defined as a shortest width between the first groove sidewall <NUM> and the second groove sidewall <NUM>. Relatedly, each groove in the plurality of tread grooves <NUM> has a groove length <NUM> extending generally parallel to the first groove sidewall <NUM> and the second groove sidewall <NUM>. Each groove in the plurality of grooves <NUM> extends generally circumferentially around the circumference of the tire <NUM>. As shown in <FIG>, each groove in the plurality of grooves <NUM> extends circumferentially around the tire <NUM> in a zig-zag pattern including alternating straight portions <NUM> joined at obtuse corners <NUM>. With respect to zig-zag grooves <NUM>, the groove length <NUM> may be defined along each of the straight portions <NUM>.

While the shape of the plurality of grooves <NUM> is shown in <FIG> and <FIG> as a zig-zag shape, a wide variety of shapes and patterns may be implemented as the groove pattern. For example, in some embodiments, the plurality of grooves <NUM> may be completely straight grooves running in a straight fashion circumferentially around the entire circumference of the tire <NUM>. In other embodiments, the plurality of grooves <NUM> may have a wavy or alternative zig-zag shape. In general, the length of the groove in the plurality of grooves <NUM> refers to a line generally parallel to (e.g., paralleling) the sidewalls <NUM>, <NUM> of the groove and extending generally around the circumference of the tire <NUM>.

Referring to <FIG>, a zig-zag shaped plurality of grooves <NUM> is shown. Each of the first tread groove <NUM>, second tread groove <NUM>, third tread groove <NUM>, and fourth tread groove <NUM> form alternatingly-angled parallel walls that include a sequence or row of stone rejectors <NUM>. Each stone rejector <NUM> in the plurality of grooves <NUM> is circumferentially spaced apart along the groove length <NUM>. Each of the raised platforms <NUM> spans between the first groove sidewall <NUM> and the opposed second groove sidewall <NUM> and extends upward from the groove bottom <NUM> (e.g., away from the body plies <NUM>). Each raised platform <NUM> is substantially parallel to an adjacent raised platform <NUM> along the groove length <NUM> of the groove <NUM>. Each protrusion <NUM> extends from the top surface <NUM> of the raised platform <NUM> in an elliptical shape (e.g., capsule) such that a top portion <NUM> of the elliptical shape is exposed.

As shown in <FIG>, each stone rejector <NUM> may have a row or sequence circumferentially spaced apart along the groove length <NUM>. In some embodiments, the stone rejectors <NUM> may be angled with respect to the rotational axis of the tire <NUM> and still provide substantially the same function as described herein. For example, the raised platform <NUM> may extend from the first groove sidewall <NUM> toward the second groove sidewall <NUM> at an angle of plus or minus <NUM>-degrees to the rotational axis of the tire <NUM>. Additionally, the protrusion <NUM> may be positioned on the top surface <NUM> at an angle of plus or minus <NUM>-degrees with respect to the sidewall of the raised platform <NUM>. In some embodiments, the protrusion <NUM> may be a spherocylinder (e.g., capsule-shaped) with only a top portion of the spherocylinder exposed and protruding from the raised platform <NUM>. In those embodiments, the protrusion <NUM> is a three-dimensional shape that includes a cylinder with hemispherical ends and has a surface area of 2π(2r+a) where "a" is the length between the two spheres and "r" is the radius of the respective half spheres. A range of forty-percent to eighty-percent (e.g., <NUM>%-<NUM>%) of the surface area may be exposed along the top surface <NUM> of the raised platform <NUM>.

As seen in <FIG>, the raised platform <NUM> may extend across one of the plurality of tread grooves <NUM> (e.g., the first tread groove <NUM>, the second tread groove <NUM>, the third tread groove <NUM>, the fourth tread groove <NUM>, etc.) in a direction substantially parallel to a rotational axis of the tire <NUM>. The raised platform <NUM> may also extend across one of the plurality of tread grooves <NUM> parallel to each other. While it is preferred that the raised platform <NUM> extend parallel to the rotational axis of the tire <NUM>, it will be appreciated that the raised platform <NUM> could be placed at a small angle to the rotational axis of the tire <NUM> and still provide substantially the same function as described herein. For example, the raised platform <NUM> slanted at an angle of plus or minus <NUM>-degrees to the rotational axis of the tire <NUM> would still result in a functional raised platform (e.g., stone rejector rib).

Referring to <FIG> and <FIG>, a cross-sectional view of the first tread groove <NUM> along the lateral line <NUM>-<NUM> of <FIG> and the lateral line <NUM>-<NUM> of <FIG>, respectively, is shown. The raised platform <NUM> extends axially (e.g., laterally) between the first groove sidewall <NUM> and the second groove sidewall <NUM>. In some embodiments, the platform width is equal to the groove width <NUM>. The raised platform <NUM> extends in the radial direction away from and out of the groove bottom <NUM> to a platform height <NUM>. In some embodiments, the raised platform <NUM> extends away from the groove bottom <NUM> in a direction substantially perpendicular to the groove bottom <NUM>. In some embodiments, the platform height <NUM> may be between <NUM>% and <NUM>% of the groove depth <NUM>. In some embodiments, the platform height <NUM> is between <NUM>% and <NUM>% of the groove depth <NUM>. In some embodiments, the platform height <NUM> is approximately <NUM>% of the groove depth <NUM>. As shown in <FIG>, the platform height <NUM> is <NUM>% to <NUM>% of the groove depth <NUM>. , In some embodiments, the groove depth <NUM> and the groove width <NUM> are dependent on tread design. In some embodiments, the platform height <NUM> may be in a range of from about <NUM> to about <NUM>. In some embodiments, the platform height <NUM> may be in a range of from about <NUM> to about <NUM>. As shown in <FIG>, the platform height <NUM> is approximately <NUM>, the unworn groove depth <NUM> is approximately <NUM>, and the groove width <NUM> is approximately <NUM>.

The protrusion <NUM>, as shown in <FIG>, may be elliptical shaped (e.g., elongated rounded shaped) defined by a major axis <NUM> and a minor axis <NUM>. While the protrusion <NUM> is described as "elliptical," the protrusion <NUM> may also more generally include an elongated shape having rounded ends and need not be precisely elliptical. The protrusion <NUM> extends axially along the top surface <NUM> of the raised platform <NUM> and is substantially centered along the top surface <NUM> such that the major axis <NUM> is substantially parallel to the groove bottom <NUM> and substantially perpendicular to the first groove sidewall <NUM> and the second groove sidewall <NUM>. In some embodiments, the protrusion <NUM> includes a more pronounced curvature along the circumference (e.g., the vertex and co-vertex are closer together), while in other embodiments, the protrusion <NUM> includes a softer curvature along the circumference (e.g., the vertex and co-vertex are further apart).

The protrusion <NUM> extends in the radial direction away from and out of the groove bottom <NUM> to a protrusion height <NUM>. Generally, the protrusion height <NUM> is substantially similar to half the minor axis <NUM> (e.g., the protrusion height <NUM> is substantially half of the length of the minor axis <NUM>). However, in some embodiments, the protrusion height <NUM> may be greater or less than the length of the minor axis <NUM> as more or less of the elliptical-shape is exposed-or left on during formation-to provide more surface area along the top surface <NUM> of the raised platform <NUM> to reject stones. In some embodiments, the protrusion <NUM> has a periphery that is entirely smooth and free of any abrupt changes in tangential direction (e.g., no sharp corners). The protrusion height <NUM> may be in a range of about <NUM> to about <NUM>. In some embodiments, the protrusion height <NUM> is in a range of from about <NUM> to about <NUM>. In some embodiments, the protrusion <NUM> and the raised platform <NUM> are pre-cured with the tread portion <NUM>. In some embodiments, the protrusion <NUM> and the raised platform <NUM> are a part of the groove mold. In some embodiments, the protrusion height <NUM> is <NUM>% to <NUM>% of the groove depth <NUM>. In the invention, the width of the protrusion <NUM> (e.g., the length of the major axis <NUM>) is between <NUM>% and <NUM>% of the groove width <NUM>. In some embodiments, the width of the protrusion <NUM> is between <NUM>% and <NUM>% of the groove width <NUM>.

Referring to <FIG>, the stone rejector height <NUM> is equal to the sum of the protrusion height <NUM> and the platform height <NUM>. Generally speaking, the stone rejectors <NUM> are applied to the groove bottom <NUM> and are configured to prevent stones from being held by (e.g., wedged within, stuck in, etc.) the groove <NUM> and potentially begin to drill (e.g., cut, penetrate) into the belts (e.g., belt package <NUM>) of the tire <NUM>. The raised platforms <NUM> are fully attached to the groove sidewalls <NUM> and <NUM> to provide extra stiffness, which will help keep the raised platforms <NUM> from being displaced by larger stones that have a higher potential to drill into the groove bottom <NUM> of the grooves <NUM>. Placing the stone rejectors <NUM> in a radial pattern (e.g., substantially parallel to the rotational axis of the tire <NUM>)allows the circumferential spaces between the stone rejectors <NUM> to open and close as the tire rolls through its footprint on the ground surface, making it harder for a larger stone to get held in the area between the raised portions <NUM>. Additionally, the protrusion <NUM> provides an additional surface that can contact and reject stones from entering the grooves <NUM>. As the tire rolls out of its footprint on the ground surface, and the space between the raised portions <NUM> and the protrusions <NUM> opens up again, any smaller stone that may have been able to fit in while the space was closed up will be able to fall out. As the tire <NUM> rolls through its footprint, the protrusions <NUM> and top surface <NUM> of the raised platforms <NUM> are compressed toward each other slightly, and as the tire rolls out of its footprint the protrusions <NUM> and top surface <NUM> of the raised platforms <NUM> spring back away from each other to their original shape. The angle of the raised platform sidewalls and protrusion and the spacing between adjacent stone rejectors <NUM> causes the circumferential gap between stone rejector <NUM> to act like a mini-groove to provide an area that is less likely to hold stones than a typical grooved bottom.

As shown in <FIG>, each stone rejector <NUM> includes a raised platform <NUM> and a protrusion <NUM> along the top surface <NUM> of the raised platform <NUM>. Each stone rejector <NUM> in the plurality of stone rejectors <NUM> may be equally circumferentially spaced around the circumference of the tire <NUM>. Raised platforms <NUM> of adjacent stone rejectors <NUM> may be spaced apart at a pitch spacing <NUM> in a range of between <NUM>% and <NUM>% of the groove width <NUM>.

In some embodiments, adjacent stone rejectors <NUM> are spaced apart at the platform base <NUM> (e.g., length of the raised platform <NUM>) by a base spacing <NUM>, in some embodiments no greater than the groove width <NUM>. At the platform top surface <NUM>, adjacent stone rejectors <NUM> are spaced apart by a top spacing <NUM> equal to or greater than the groove width <NUM>. Such dimensioning of the stone rejectors <NUM> relative to the groove width <NUM> provides that opposed stone rejector sidewalls (e.g., first sidewall <NUM> and second sidewall <NUM>) of adjacent stone rejectors <NUM> will resist retention between the adjacent stone rejectors <NUM> of stone having dimensions equal to or greater than the groove width <NUM>.

Each raised platform <NUM> includes a circumferentially facing first sidewall <NUM> and a circumferentially facing second sidewall <NUM>. The first sidewall <NUM> and the second sidewall <NUM> are sloped at an angle <NUM> with respect to a radius of the tire <NUM> such that the first sidewall <NUM> is a forward facing sloped rejector wall and the second sidewall <NUM> is a rearward facing sloped rejector wall. The angle <NUM> may be in a range of about <NUM>-degrees to about <NUM>-degrees with respect to the radius of the tire <NUM>. In other embodiments, the angle <NUM> is in a range of from about <NUM>-degrees to about <NUM>-degrees. As shown in <FIG>, each raised platform <NUM> will have a wider platform base <NUM> and a narrow platform top surface <NUM>. Accordingly, the raised platform <NUM> may be described as rectangular in cross-section or as substantially vertical from the platform base <NUM> to the platform top surface <NUM>. In some embodiments, the platform top surface <NUM> has a width <NUM> in a range from <NUM> to <NUM>. In other embodiments, the platform top surface <NUM> has a width <NUM> in the range of <NUM> to <NUM>.

In some embodiments, the protrusion <NUM> may be formed by removing a top excess surface from the triangular shape <NUM> of the raised platform <NUM>. The triangular shape <NUM> is the extending first sidewall <NUM> meeting the second sidewall <NUM> at a point. In other embodiments, the protrusion <NUM> and the raised platform <NUM> are formed as a single mold. In one example embodiment, the platform height <NUM> is approximately <NUM>, the protrusion height is approximately <NUM>, the angle <NUM> is approximately <NUM>°, the unworn groove depth <NUM> is approximately <NUM>, the groove width <NUM> is approximately <NUM>, the top spacing <NUM> is approximately <NUM>, and the pitch spacing <NUM> is approximately <NUM>.

Turning to <FIG>, a schematic cross-sectional view tread groove along radial line <NUM>-<NUM> of a tread region with angled raised platforms <NUM> is shown, according to an example embodiment. The plurality of stone rejectors <NUM> is similar to the plurality of stone rejectors <NUM> of <FIG>. A difference between the plurality of stone rejectors <NUM> and the plurality of stone rejectors <NUM> is the plurality of stone rejectors <NUM> includes angled sidewalls along the raised platforms <NUM>. Accordingly, similar numbering will be used for similar features of the plurality of stone rejectors <NUM> and the plurality of stone rejectors <NUM>. Each stone rejector <NUM> includes a raised platform <NUM> and a protrusion <NUM> along the top surface <NUM> of the raised platform <NUM>. Each stone rejector in the plurality of stone rejectors <NUM> may be equally circumferentially spaced around the circumference of the tire <NUM>. Raised platforms <NUM> of adjacent stone rejectors <NUM> may be spaced apart at a pitch spacing <NUM> in a range of between <NUM>% and <NUM>% of the groove width <NUM>.

In some embodiments, adjacent stone rejectors <NUM> are spaced apart at the platform base <NUM> by a base spacing <NUM>, in some embodiments no greater than the groove width <NUM>. At the top surface <NUM>, adjacent stone rejectors <NUM> are spaced apart by a top spacing <NUM> equal to or greater than the groove width <NUM>. Such dimensioning of the stone rejectors <NUM> relative to the groove width <NUM> provides that opposed stone rejector sidewalls (e.g., first sidewall <NUM> and second sidewall <NUM>) of adjacent stone rejectors <NUM> will resist retention between the adjacent stone rejectors <NUM> of stone having dimensions equal to or greater than the groove width <NUM>.

Each raised platform <NUM> includes a circumferentially facing sloped first sidewall <NUM> and a circumferentially facing sloped second sidewall <NUM>. The first sidewall <NUM> and the second sidewall <NUM> are sloped at an angle <NUM> with respect to a radius of the tire <NUM> such that the first sidewall <NUM> is a forward facing sloped rejector wall and the second sidewall <NUM> is a rearward facing sloped rejector wall. The angle <NUM> may be in a range of about <NUM>-degrees to about <NUM>-degrees with respect to the radius of the tire <NUM>. In other embodiments, the angle <NUM> is in a range of from about <NUM>-degrees to about <NUM>-degrees. As shown in <FIG>, the angle <NUM> is approximately <NUM>-degrees. As shown in <FIG>, each raised platform <NUM> will have a wider platform base <NUM> and a narrow top surface <NUM>. Accordingly, the raised platform <NUM> may be described as pyramidal in cross-section or as vertically tapered from the platform base <NUM> to the top surface <NUM>. In some embodiments, the top surface <NUM> has a width <NUM> in a range from <NUM> to <NUM>. In other embodiments, the top surface <NUM> has a width <NUM> in the range of <NUM> to <NUM>.

In some embodiments, the protrusion <NUM> may be formed by removing a top excess surface from the triangular shape <NUM> of the raised platform <NUM>. The triangular shape <NUM> is the extending first sidewall <NUM> meeting the second sidewall <NUM> at a point. In other embodiments, the protrusion <NUM> and the raised platform <NUM> are formed as a single mold. In one example embodiment, the platform height <NUM> is approximately <NUM>, the angle <NUM> is approximately <NUM>°, the unworn groove depth is approximately <NUM>, the groove width <NUM> is approximately <NUM>, the top spacing <NUM> is approximately <NUM>, and the pitch spacing <NUM> is approximately <NUM>.

It should be noted that the term "example" as used herein to describe various embodiments is intended to indicate that such embodiments are possible examples, representations, and/or illustrations of possible embodiments (and such term is not intended to connote that such embodiments are necessarily extraordinary or superlative examples).

As utilized herein, the term "substantially" and similar terms are intended to have a broad meaning in harmony with the common and accepted usage by those of ordinary skill in the art to which the subject matter of this invention pertains. It should be understood by those of skill in the art who review this invention that these terms are intended to allow a description of certain features described and claimed without restricting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or alterations of the subject matter described and claimed (e.g., within plus or minus five percent of a given angle or other value) are considered to be within the scope of the invention as recited in the appended claims. The term "approximately" when used with respect to values means plus or minus five percent of the associated value.

Directions are also stated in this application with reference to the axis of rotation of the tire. The terms "upward" and "upwardly" refer to a general direction towards the tread of the tire, whereas "downward" and "downwardly" refer to the general direction towards the axis of rotation of the tire. Thus, when relative directional terms such as "upper" and "lower" are used in connection with an element, the "upper" element is spaced closer to the tread than the "lower" element. Additionally, when relative directional terms such as "above" or "below" are used in connection with an element, an element that is "above" another element is closer to the tread than the other element. Additionally, the term "radially inner" refers to an element that is closer to the axis of rotation than is a "radially outer" element. The terms "axially inward" and "axially inwardly" refer to a general direction towards the equatorial plane of the tire, whereas "axially outward" and "axially outwardly" refer to a general direction away from the equatorial plane of the tire and towards the sidewall of the tire.

The terms "coupled," "connected," and the like as used herein mean the joining of two members directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or moveable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.

It is important to note that the construction and arrangement of the various exemplary embodiments are illustrative only. Although only a few embodiments have been described, those skilled in the art will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the claims.

Claim 1:
A tread portion (<NUM>) comprising:
a generally circumferentially extending groove (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) defined therein, the groove (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having a groove cross-section defined by a groove bottom (<NUM>), a first groove sidewall (<NUM>), and a second groove sidewall (<NUM>), the second groove sidewall (<NUM>) opposite and substantially parallel to the first groove sidewall (<NUM>), the groove (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) having a groove width (<NUM>) defined between the first groove sidewall (<NUM>) and the second groove sidewall (<NUM>); and
a plurality of stone rejectors (<NUM>, <NUM>) extending between the first groove sidewall (<NUM>) and the second groove sidewall (<NUM>), each of the stone rejectors (<NUM>, <NUM>) in the plurality of stone rejectors (<NUM>, <NUM>) circumferentially spaced from an adjacent stone rejector of the plurality of stone rejectors (<NUM>, <NUM>), wherein each of the stone rejectors (<NUM>, <NUM>) comprises a raised platform (<NUM>, <NUM>) and a protrusion (<NUM>), the raised platform (<NUM>, <NUM>) extending axially from the first groove sidewall (<NUM>) to the second groove sidewall (<NUM>) and the protrusion (<NUM>) extending from a top surface (<NUM>, <NUM>) of the raised platform (<NUM>, <NUM>),
characterized in that
the protrusion (<NUM>) has an elongated shape that extends axially along the top surface (<NUM>, <NUM>) to a width that is <NUM>% to <NUM>% of the groove width (<NUM>).