Truck tire with high angle groove spaced from shoulder rib

Abstract

A heavy truck tire tread (10) is provided that has a rib (18) and first (16) and second tread grooves (16) that are oriented so as to extend in both the lateral and longitudinal directions. A shoulder rib (36) is present that is bound by a first tread edge on one side and by a circumferential feature of the tread on the other. The first and second tread grooves (16, 18) are located inboard from the circumferential feature in the lateral direction, and terminate at first and second tread groove terminal ends that are spaced from and do not engage the circumferential feature.

Description

TRUCK TIRE WITH HIGH ANGLE GROOVE SPACED FROM SHOULDER RIBSTATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0001] This invention was made with government support under the Vehicle Technology program Award Number DE-EE0009857 awarded by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE). The Government has certain rights in the invention.FIELD OF THE INVENTION

[0002] The subject matter of the present invention relates to a truck tire tread that has angled grooves that are arranged so as to avoid the initiation of irregular wear. More particularly, the present application involves a truck tire tread that features an angled groove that is spaced from and free from engagement with a circumferential feature that defines a shoulder rib to better manage aggression and irregular wear performance.BACKGROUND OF THE INVENTION

[0003] Manufacturers of heavy commercial vehicle tires have made huge progress in developing tire architectures and tire materials that allowed them to increase the wear resistance of tire treads and reduce the rolling resistance of tires while in the same time improving their level of grip and resistance to road hazard. Tread patterns may include a series of circumferential grooves between which a series of circumferential ribs are positioned. The circumferential direction, which can also be described as the longitudinal direction, extends around the central axis of the tire and is oriented at a ninety degree angle to the lateral direction of the tire. The circumferential grooves and ribs extend 360 degrees around the tire and are oriented so that they have a component of extension in the longitudinal / circumferential direction but no component of extension in the lateral direction. A variation of tread patterns involves orienting the ribs and grooves so that they are not circumferential ribs and grooves, but rather include a component of extension in the lateral direction. In this regard, the tread grooves and ribs can extend from the shoulder edges inward in the lateral direction while at the same time extending some amount in the longitudinal direction to result in an “angled” orientation of these tread features.

[0004] The use of angled ribs and grooves achieves some advantages over tread designs that include only circumferential grooves and ribs. However, the use of angled grooves and ribs results in areas of wear on the outside portion of the ribs that occur at a faster rate than other areas of the rib and may propagate inward. The tire will then have a section that is worn faster than the rest or having irregular wear leading to complaints from the ow er of the tire, reduced tire performance, and even early removal from sendee of the tire. In this regard, as the high angle grooves transition into the shoulder region of the tread they create small tread features or tread features that have very acute angles. These small or acute angle features will serve as the sites for the initiation of irregular wear. One w ay to address this problem is to drastically reduce the angle of the inclined grooves as they approach the shoulder region. This approach can be seen in the prior art design shown in Fig. 1 in which the inclined grooves change angle at the shoulder so that they are no longer completely linear in shape. However, this approach requires that the inclined grooves change angles and open into the shoulder thus limiting what types of shoulder designs and groove designs can be used. These designs may still suffer from having smaller or acute tread features. As such, there remains room for variation and improvement within the art.BRIEF DESCRIPTION OF THE DRAWINGS

[0005] A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art. is set forth in the specification, which makes reference to the appended figures, in which:

[0006] Fig. 1 is a perspective view of a heavy truck tire of the prior art.

[0007] Fig. 2 is top view of tread in accordance w ith one exemplary embodiment.

[0008] Fig. 3 is a top view- of tread in accordance with another exemplary embodiment.

[0009] Fig. 4 is a cross-sectional view taken along line 4-4 of Fig. 3.

[0010] Fig. 5 is a top view of tread in accordance with yet another exemplary embodiment.

[0011] Fig. 6 is a cross-sectional view taken along line 6-6 of Fig. 5.

[0012] Fig. 7 is a cross-sectional view- taken along line 7-7 of Fig. 5.DETAILED DESCRIPTION OF THE INVENTION

[0013] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations.

[0014] The present invention provides for a tread 10 for a heavy duty truck tire 12 with angled grooves 14, 16 and ribs 18. and with a shoulder rib 36. The shoulder rib 36 extends from a tread edge 28 to a circumferential feature 26 of the tread 10 that could be, for example, a sipe or a groove. The first tread groove 14 is spaced from and free from engagement with the circumferential feature 26. This arrangement prevents the formation of very small tread features and / or tread features with very sharp acute angles in this area of the tread 10. The elimination of these small pointed features improves the aggression damage and irregular wear performance of the tread 10. The provided arrangement also allows for greater flexibility in selecting the design for the shoulder rib 36 such as one that is solid, siped, or blocky with lateral grooves 44.

[0015] Fig. 1 shows a prior tire 12 that is a heavy duty truck tire 12. In this regard, the tire 12 is not designed for nor used with a car, motorcycle, or light truck (payload capacity less than 4,000 pounds), but is instead designed for and used with heavy duty trucks such as 18 wheelers, garbage trucks, or box trucks. The tire 12 may be a steer tire, a drive tire, a trailer tire, or an all position tire. The tire 12 includes a casing 64 onto which a tread 10 is disposed thereon. The tread 10 can be manufactured with the casing 64 and formed as a new tire 12, or the tread 10 can be a retread band that is attached to the casing 64 at some point after the casing 64 has already been used to form a retreaded tire 12. This is the case with all of the designs shown and described herein. They may all be tread designs of a brand new tire 12, or may be tread designs of a tread 10 for use in a retread tire 12. The central axis of the tire 12 extends through the center of the casing 64, and the lateral direction 22 of the tire 12 is parallel to the central axis. The radial direction 24, referred to also as the thickness direction 24, of the tire 12 is perpendicular to the central axis and the tread 10 is located farther from the central axis in the thickness direction 24 than the casing 64. The tread 10 extends all the way around the casing 64 in the circumferential direction 20, also referred to as the longitudinal direction 20, of the tire 12 and circles the central axis 360 degrees. The tread 10 includes a series of grooves and ribs that form a tread pattern.A rolling tread width 32 extends in the lateral direction 22 from one shoulder edge 28 of the tread 10 to an opposite shoulder edge 30 of the tread 10. The rolling tread width 32 represents that portion of the tread 10 that engages the ground through normal operation of the tire 12, and the shoulder edges 28, 30 may engage the ground as well as the area between these locations in the lateral direction 22.

[0016] Fig. 2 is a top view of a tread 10 that can be part of a tire 12 or a retread band that is produced and subsequently attached to a casing 64 to form a retread tire 12. The same tread pattern can repeat throughout the entire longitudinal length of the tread 10. The tread 10 has a first tread groove 14 and a second tread groove 16 that are in sequence next to one another in the longitudinal direction 20. The grooves 14, 16 can be variously shaped and have widths that can be equal to or greater than 2 millimeters. The shape of the center portion of the grooves 14, 16 can be different than the shape of the shoulder portion of the grooves 14, 16 or the shape of the grooves 14, 16 can be the same along their entire depth in the thickness direction 24. A rib 18 is defined between the grooves 14, 16 in the longitudinal direction 20. The rib 18 is not a circumferential rib in that it does not extend all the way around the tread 10 in the longitudinal direction 20 when part of the tire 12. Instead, the rib 18 extends from circumferential feature 26 to the center of the tread 10. The rib 18 is angled relative to the longitudinal direction 20 so that the rib 18 extends so as to have a component of extension in both the longitudinal direction 20 and in the lateral direction 22. In contrast, a circumferential rib would have a component of extension in the longitudinal direction 20 and no component of extension in the lateral direction 22. A lateral midpoint 34 of the tread 10 is located at the halfway point in the lateral direction 22 between the first tread edge 28 and the second tread edge 30. Although shown as being at the lateral midpoint 34, the grooves 14, 16 could be short or past the lateral midpoint 34, and may or may not be connected to one another in other embodiments. The various grooves 14, 16 are shown as being staggered with the set on the other lateral half of the tread 10, but this likewise need not be true in other embodiments as the grooves 14, 1 and those on the opposite lateral side could engage one another and form a single groove.

[0017] The first tread groove 14 and the second tread groove 16 likewise are not circumferential grooves in that they extend so as to have a component of extension in both the longitudinal direction 20 and the lateral direction 22. The grooves 14, 16 are spaced from and not in engagement with the tread edges 28, 30 and the circumferential feature 26 and extend to terminate at the center of the tread 10. The grooves 14, 16 may extend to andengage the lateral midpoint 34, and may in fact cross the lateral midpoint 34 to the opposite lateral half of the tread 10. The rib 18 may likewise engage the lateral midpoint 34 or extend beyond it to the opposite lateral half of the tread 10. In other embodiments, the grooves 14, 16 and rib 18 need not extend to and engage the lateral midpoint 34. The grooves 14, 16 are isolated in that they do not engage any other grooves of the tread 10. However, in other arrangements the grooves 14, 16 may engage other grooves of the tread 10. The rib 18 can likewise engage other ribs of the tread 10 in other arrangements.

[0018] The grooves 14. 16 and rib 18 are straight and do not change components of extension in the longitudinal and lateral directions 20, 22 along their lengths as shown in Fig. 2. In other embodiments, the grooves 14, 16 and rib 18 can have different components of extension in the lateral and longitudinal directions 20, 22 at one or more points along their entire lengths. This would result in the grooves 14, 16 and rib 18 being angled relative to the longitudinal direction 20. In other arrangements, the grooves 14, 16 and rib 18 may curve or have two, three, four, or more angular changes along their lengths.

[0019] The first tread groove 14 is shaped and sized the same as the second tread groove 16 and can have the same cross-sectional shape and size as one another. In the embodiment shown, the first and second tread grooves 14, 16 are both linear in extension. The first groove 14 has a first tread groove first terminal end 38 that is the portion of the first tread groove 14 that is closest to the circumferential feature 26 in the lateral direction 22. The first groove 14 extends to and terminates at a first tread groove second terminal end 48 that is located on an end of the first groove 14 that is opposite from the first tread groove first terminal end 38. In order to describe the angled orientation of the first tread groove 14, a first lateral line 52 extends through the first tread groove first terminal end 38 and does not have a component of extension in the longitudinal direction 20. A first tread groove reference line 50 extends through both the first tread groove first terminal end 38 and the first tread groove second terminal end 48. A first tread groove angle 54 is defined between the first lateral line 52 and the first tread groove reference line 50 and is oriented towards the lateral midpoint 34 so to face the lateral midpoint 34 and open into and engage the lateral midpoint 34 so that the lateral midpoint 34 is within the first tread groove angle 54.

[0020] The first tread groove angle 54 may be including and from 40 degrees - 85 degrees, 45 degrees - 80 degrees, 50 degrees - 75 degrees, 55 degrees - 70 degrees, 60 degrees - 65 degrees, 40 degrees- 45 degrees, 45 degrees - 50 degrees, 50 degrees - 55 degrees, 55 degrees - 60 degrees, 60 degrees - 65 degrees, 65 degrees - 70 degrees, 70degrees - 75 degrees, 75 degrees - 80 degrees, 80 degrees - 85 degrees, 40 degrees - 50 degrees, 50 degrees - 60 degrees, 60 degrees - 70 degrees, or 70 degrees - 85 degrees. Preferably, the first tread groove angle 54 is including and from 50 degrees - 75 degrees. In other arrangements, the first tread groove angle 54 is including and from 55 degrees - 70 degrees, 60 degrees - 67 degrees, 61 degrees - 68 degrees, 62 degrees - 66 degrees, or 58 degrees - 73 degrees.

[0021] The rib 18 is located between the first and second tread grooves 14 and 16 and can extend along and terminate at the inboard most extensions of the grooves 14 and 16. The rib 18 could also be thought of as terminating at a groove that the grooves 14 and 16 intersect near the center of the tread 10, but such an intersecting groove is not shown in Fig. 2. Further, the rib 18 may in some embodiments extend beyond the grooves 14, 16 in the lateral and longitudinal directions 22, 20 until such time as the rib 18 terminates at additional grooves or at the circumferential feature 26, such as that shown in Fig. 2. The rib 18 although primarily extending in the longitudinal direction 20 extends a large amount in the lateral direction 22. With respect to the rolling tread width 32, the rib 18 extends at least 30% of the length of the rolling tread width 32 in the lateral direction 22. As such, the rib 18 extends across at least 30% of the width of the rolling tread width 32 of the tire 12. However, in other embodiments the rib 18 does not extend across at least 30% of the width of the rolling tread width 32, and extends across less than 30% of the width of the rolling tread width 32 so as to extend from 20% to 29% of the width of the rolling tread width 32. In a similar fashion, the grooves 14 and / or 16 could extend across at least 30% of the length of the rolling tread width 32, and in other embodiments may extend from 20% to 29% of the length of the rolling tread width 32.

[0022] The second tread groove 16 can be angled the same way as the first tread groove 14, and a repeat of this information is not necessary. The angled orientation of the second tread groove 16 may be the exact same as the first tread groove 14. or it could be different than that of the first tread groove 14 but within one of the ranges as previously discussed. The second tread groove 16 may be sized and shaped the exact same way as the first tread groove 14, or these two grooves 14, 16 could be different from one another.

[0023] The tread 10 features a circumferential feature 26 that forms a boundary of the shoulder rib 36 of the tread 10. The circumferential feature 26 can be a continuous feature that extends completely 360 degrees around the central axis of the tire 12. Alternatively, the circumferential feature 26 could be an intermittent feature that is not completelycontinuous 360 degrees around the tire 12, but instead has discontinuous portions at various locations around the 360 degrees. The circumferential feature 26 in Fig. 2 is an open groove. As described herein, a groove is an opening in the upper surface 66 larger than 2 millimeters that extends a depth into the tread 10 in the thickness direction 24. The first and second tread grooves 14, 16 are spaced from and not in engagement with the circumferential feature 26. In this regard, the first and second tread grooves 14, 16 are spaced in the lateral direction 22 from the circumferential feature 26. The first tread groove first terminal end 38 is the portion of the first tread groove 14 that is closest to the circumferential feature 26 in the lateral direction 22.

[0024] The first tread groove first terminal end 38 is spaced a distance 56 from the circumferential feature 26 as measured only in the lateral direction 22 therefrom. This distance 56 is measured to the point where the circumferential feature 26 begins, and the first tread groove first terminal end 38 may be the portion of the first tread groove 14 that is at the closest lateral extent to this part of the circumferential feature 26. If the circumferential feature 26 is j agged, angled, or undulating the distance 56 is measured from the first tread groove first terminal end 38 completely in the lateral direction 22 until it first encounters the circumferential feature 26, even though other portions of the circumferential feature 26 are more inboard than this point in the lateral direction 22. The distance 56 may be between and including 5-50 millimeters, and preferably between and including 20-30 millimeters. In other embodiments, the distance 56 is between and including 5-15 millimeters, 15-25 millimeters, 25-35 millimeters, 35-45 millimeters, 45-50 millimeters, 15-35 millimeters, 20-25 millimeters, 15-30 millimeters, 35-50 millimeters, 10-40 millimeters, 15-40 millimeters, 15-50 millimeters, 20-50 millimeters, 30-50 millimeters, 18-28 millimeters, 8-28 millimeters, 26-44 millimeters, 27-38 millimeters, 27-34 millimeters, or 28-33 millimeters. The distance 56 could be other distances in other embodiments, and is selected so that the tread 10 design does not have small features or sharp pointed features formed by an intersection between the first tread edge 28 and the circumferential feature 26. As such, the listed values for the distance 56 are selected so as to be large enough to avoid sharp, pointy features in the tread 10, yet small enough so that the benefits of water evacuation from the large angled tread grooves 14, 16 are not lost.

[0025] The second tread groove 16 has a second tread groove first terminal end 40 that is the portion of the second tread groove 16 that is closest to the circumferential feature 26 measured only in the lateral direction 22 therefrom. The second tread groove first terminalend 40 is not in engagement with, and is spaced a distance from, the circumferential feature 26 in the lateral direction 22. This spacing and distance can be the same as that previously discussed with respect to the distance 56 and a repeat of this information is not necessary. The spacing of the second tread groove first terminal end 40 can be spaced the same distance from the circumferential feature 26 as the distance 56, or this distance and distance 56 could be different from one another. The terminal ends 38, 40 can be located at the same position in the tread 10 in the lateral direction 22. The terminal ends 38, 40 can be spaced from one another in the longitudinal direction 20 a greater distance than is the distance 56.

[0026] It is therefore the case that the first and second tread grooves 14, 16, and in this and other embodiments all of the tread grooves of the tread 10, are spaced from and not in engagement with the circumferential features 26. This spacing avoids the need of the first and second tread grooves 14, 16 to be angled as they approach their exit to the tread edges 28, 30 or the shoulder ribs 36. This spacing of the first and second tread grooves 14, 16 also avoids the need for the main rain grooves of the tread 10 to exit at the shoulder so that the tread 10 can be designed with a shoulder rib 36 that is a solid rib, a rib with small shoulder notches and shallow decorative elements, a siped shoulder rib 36 , a blocky shoulder rib 36, or any other type of shoulder rib 36. As such, the offsetting in the lateral direction 22 allows for the provision of a shoulder rib 36 that can be variously configured to optimize the design or achieve other design flexibility. The shoulder rib 36 can be designed independently of the design of the central section of the tread 10 between the two circumferential features 26. The spacing of the grooves 14, 16 from the circumferential feature 26 in the lateral direction 22 allows for better management of the aggression and irregular wear performance of the tread 10 across a wider usage domain of the tire 12. In addition to allowing for the use of a range of shoulder rib 36 designs, the spacing as described herein provides a tread 10 that is more robust in terms of tread aggression damage and irregular wear. The design avoids the presence of small, pointed or acute tread blocks at the shoulder or at the end of the rain grooves.

[0027] The tread 10 can be designed to have certain performance characteristics if the tread 10 is rolled in a particular direction in the longitudinal direction 20. This direction is called the rolling direction 60 and is the direction of rotation of the tread 10 in the longitudinal direction 20 that the tread 10 is designed to rotate to achieve desired performance. The tread 10 shown in Fig. 2 is a directional tread 10, and the features arearranged on the tread 10 to cause desired performance characteristics in the rolling direction 60. The first and second tread grooves 14, 16 are arranged on the tread 10 so that the grooves 14, 16 extend inboard in the lateral direction 22 at the same time as extending forward in the rolling direction 60.

[0028] The shoulder rib 36 is defined on one side of the tread 10 as being the area between the first tread edge 28 and the circumferential feature 26. The shoulder rib 36 has a width 62 that is the distance in the lateral direction 22 that extends from the first tread edge 28 to the circumferential feature 26. The width 62 is measured to the closest portion of the circumferential feature 26 in the lateral direction 22. If the circumferential feature 26 is wary, angled, undulated, or otherwise does not have a single position in the lateral direction 22, then the width 62 can be the width of the shoulder rib 36 that is the smallest width that can be measured in any of the longitudinal locations of the shoulder rib 36. The shoulder rib 36 can be designed in any manner and can be featureless or have various features formed therein. The shoulder rib 36 has lateral grooves 44 that extend completely from the first tread edge 28 to the circumferential feature 26 such that it engages both the first tread edge 28 and the circumferential feature 26. The lateral grooves 44 extend from the upper surface 66 into the tread 10 so as to have a depth that is the same as the depth of the first and second tread grooves 14, 16 in the thickness direction 24. The lateral grooves 44 are openings in the upper surface 66 and are greater than 2 millimeters in width. The lateral grooves 44 split the shoulder rib 36 into a series of sequential blocks in the longitudinal direction 20. The lateral grooves 44 are directional in that the lateral grooves 44 extend inward in the lateral direction 22 as they extend forward in the longitudinal direction 20 in the same direction as is the rolling direction 60.

[0029] The tread 10 includes a plurality of sipes 46 which are openings in the upper surface 66 that extend into the tread 10 in the thickness direction 24 having a width that is less than or equal to 2 millimeters. The sipes 46 may be described as being castle type sipes 46 in that they have a bracket type shape, although some of the sipes 46 are not bracket in shape but are instead straight. The sipes 46 engage both the first tread groove 14 and second tread groove 16 such that the rib 18 has sipes 46 therein that extend completely across its width. Some of the sipes 46 engage and extend from the circumferential feature 26 to the first tread groove 14, but these sipes 46 do not engage the second tread groove 16. Other ones of the sipes 46 engage the circumferential feature 26 and the second tread groove 16, but do not engage the first tread groove 14. Some of the sipes 46 are arrangedin a row such that they extend from the circumferential feature 26 to the lateral midpoint 34 in a linear manner in an angle to the lateral direction 22 such that the row has a component of extension in the longitudinal direction 20 that is opposite to that of the rolling direction 60. Once the row of sipes 46 engages the lateral midpoint 34. the angle of the row remains the same but its direction changes to have a component of extension in the longitudinal direction 20 that is in the same direction as that of the rolling direction 60. Although changing direction at the lateral midpoint 34, in other embodiments the row of sipes 46 could instead change direction at a location near the lateral midpoint 34 but not exactly at the lateral midpoint 34, for instance at a location that is plus or minus 30 millimeters to the lateral midpoint 34 in the lateral direction 22. This row then extends to the opposite circumferential feature 26 at which point it terminates. The sipes 46 are present along a majority of the rolling tread width 32 and between the pair of circumferential features 26, but the sipes 46 are not present in either of the shoulder ribs 36.

[0030] The tread grooves 14, 16 have been described as not engaging the circumferential feature 26. The sipes 46 may in fact engage the tread grooves 14, 16 and extend to and engage the circumferential feature 26. However, there are no grooves, which are described as being greater than 2 millimeters in width, that engage both the tread groove 14 and the circumferential feature 26, and there are no grooves that engage both the tread groove 16 and circumferential feature 26. The sipes 46 are thus distinct features of the tread 10 and are not part of the first tread groove 14 or the second tread groove 16, or any other ones of the tread grooves of the tread 10.

[0031] Another embodiment of the tread 10 is shown with reference to Fig. 3. The first and second tread grooves 14, 16 are again angled so as to have components of extension in both the longitudinal and lateral directions 20, 22 and are not completely open grooves from one end to the other, but instead are partially open. With reference as well to the cross-sectional view in Fig. 4, the grooves 14, 16 extend a length on the upper surface 66 that are an open groove having a width greater than 2 millimeters, and then followed by a closed section that can be a sipe that has a width 2 millimeters or smaller, and then alternating these closed and open sections along the rest of the length of the grooves 14, 16. Upon extension of the grooves 14, 16 from the upper surface 66 into the tread 10, the grooves 14, 16 alternate widths so that they alternate between grooves and sipes. One half of the grooves 14, 16 are over 2 millimeters in width, and the other half of the grooves 14,16 are 2 millimeters or less in width depending upon their spot in the thickness direction 24. The first and second tread grooves 14, 16 are spaced from and not in engagement with the circumferential feature 26. The distance 56 and that of the second tread groove 16 can be the same as that previously discussed with respect to the tread grooves 14, 16 of the Fig. 2 embodiment and a repeat of this information is not needed.

[0032] The first and second tread grooves 14, 16 extend to and engage the lateral midpoint 34 and extend some distance into the opposite lateral half of the tread 10. The grooves 14, 16 alternate so that sequential grooves 14, 16 in the longitudinal direction 20 have alternating open or sipe sections at the upper surface 66 closest to the circumferential feature 26. The tread grooves 14, 16 have a depth in the thickness direction 24 that two or three millimeters deeper than the depth of the sipes 46, although in some instances the depths of the grooves 14, 16 and sipes 46 may all be the same.

[0033] The sipes 46 are again configured so as to engage and extend from the two circumferential features 26 in rows that move away from the rolling direction 60 upon their movement inboard towards the lateral midpoint 34. This sipes 46 are straight and do not have any castle features. The sipes 46 extend so as to be positioned in straight rows from the circumferential features 26 at an angle to the lateral direction 22 to extend rearward in the longitudinal direction 20 in the direction opposite the rolling direction 60. The rows engage one another at the lateral midpoint 34, and in other instances near the lateral midpoint such as within 30 millimeters of the lateral midpoint 34 in the lateral direction 22.

[0034] The circumferential feature 26 is a sipe that can have a teardrop at its bottom, or that does not have a teardrop at its bottom. In fact, any of the sipes described herein may or may not have a teardrop located at its bottom. The circumferential feature 26 extends completely in the longitudinal direction 20 and has no angles, curves or other features that cause it to have a local portion with a component of extension in the lateral direction 22. The circumferential feature 26 has a pin hole feature 42 located at the intersection of the circumferential feature 26 with the sipe 46. The pin hole feature 42 is cylinder shaped and extends from the upper surface 66 to a depth that is the same as the depth as the rest of the circumferential feature 26. The pin hole feature 42 has a diameter that is greater than the width of the sipe portions of the circumferential feature 26 and is engaged by two of these sipe portions in addition to engagement by the sipe 46. The sipes 46 can have a depth into the tread 10 from the upper surface 66 that is the same depth as the pin hole features 42 and the sipe portions of the rest of the circumferential feature 26. The first and second treadgrooves 14, 16 do not engage the circumferential feature 26. When referred to as not engaging the circumferential features 26, there are no grooves that engage both the circumferential feature 26 and the tread grooves 14, 16 but instead at most sipes 46 that engage these components. As such, sipes 46 which are openings that are 2 millimeters or less in width are not counted as causing engagement between the circumferential feature 26 and the tread grooves 14, 16.

[0035] The shoulder rib 36 is featureless in that it does not have any grooves or sipes therein and is a solid rib that extends completely 360 degrees about the axis of the tire 12. The shoulder rib 36 has a width 62 that is measured from the first tread edge 28 to the nearest touchpoint of the circumferential feature 26 along a direction of measurement that is completely in the lateral direction 22. If the first tread edge 28 is not completely linear in shape but has shoulder notches or is otherwise angled or shaped so that it does not all have a single position in the lateral direction 22, then the width 62 is measured from the portion of the first tread edge 28 that is the most inboard and closest to the lateral midpoint 34 in the lateral direction 22.

[0036] Another exemplary embodiment of the tread 10 is show n with reference to Figs. 5-7. In this embodiment, the first and second tread grooves 14, 16 are spaced from and free from engagement with the circumferential feature 26. The distance 56 from the circumferential feature 26 to the first tread groove first terminal end 38, and the distance from the circumferential feature 26 to the second tread groove first terminal end 40 can be the same as that previously discussed. The first and second tread grooves 14. 16 are not in engagement with any other grooves of the tread 10. As discussed herein, the various first and second tread grooves 14, 16 may be unconnected with one another such that they do not engage one another or such that no other groove engages both of them. Alternatively, the first and second tread grooves 14, 16 could be connected to one another via a groove, but this groove again will not engage the circumferential feature 26. Sipes 46 that could be present in the tread 10 do no not count as connecting the first and second tread grooves 14, 16 to one another or to the circumferential feature 26. The first and second tread grooves 14, 16 are open grooves and are not completely linear in extension but instead have a curved shape. In order to calculate the first tread groove angle 54. the ends 38, 40 are again marked based upon the point closest to the circumferential feature 26 in the lateral direction 22 and based upon the point farthest from the circumferential feature 26 in the lateral direction 22. The first tread groove reference line 50 extends between these two ends 38, 40 and the firsttread groove angle 54 is measured from the first lateral line 52 to the first tread groove reference line 50 so as to open towards the lateral midpoint 34. The first tread groove angle 54 can be sized as previously discussed.

[0037] There are no sipes 46 present in the middle section of the tread 10 that is between the pair of circumferential features 26. The circumferential feature 26 is an open groove that has bridging. Bridging is a feature of a groove in which the depth of the groove in the thickness direction 24 is not the same along the entire length of the groove. Instead, at intermittent points the depth of the groove becomes more shallow to cause a greater connection between the two tread 10 features that bound the groove. With reference to the cross-sectional views in Figs. 6 and 7, bridge portions 68 can be seen to fill a portion of the depth of the circumferential feature 26 such that the circumferential feature 26 does not extend a depth in the thickness direction 24 that is the same depth as the shoulder sipes 58 or the tread grooves at locations of the bridge portion 68, but do in fact extend the same depth in the thickness direction 24 as the shoulder sipes 58 and grooves in locations where the bridge portions 68 are not present. The bridge portions 68 are not half of the depth of the circumferential features 26 but are instead of a thickness that is less than half of the height of the circumferential features 26.

[0038] The shoulder rib 36 does not have any grooves but has a series of shoulder sipes 58 that extend from and engage both the first tread edge 28 and the circumferential feature 26. The portion of the circumferential feature 26 that is engaged by the shoulder sipes 58 is the portion that does not have the bridge portion 68 such that the shoulder sipes 58 do not engage the bridge portions 68. The shoulder sipes 58 are angled with respect to the longitudinal direction 20 so as to have components of extension in both the longitudinal and lateral directions 20, 22. From the circumferential feature 26, the shoulder sipes 58 extend outboard in the lateral direction 22 towards the first tread edge 28 and have a component of extension forward in the longitudinal direction 20 that is in the same direction as the rolling direction 60. The shoulder sipes 58 have the same depth in the thickness direction 24 as do the first and second tread grooves 14, 1 and the same as the portions of the circumferential feature 26 that do not feature the bridge portions 68. The first and second tread grooves 14. 16 in the various embodiments may include bridge portions 68 as well in some embodiments.

[0039] The tread 10 can also include ornamental features that look like grooves or other elements that may seem to place the circumferential feature 26 into communication withthe tread grooves 14, 16 or tread edges 28, 30. These ornamental features may have a width that is larger than 2 millimeters, but their depth is generally very' shallow so that they function primarily as an ornamental object and not as a functional object. As such, in order to be defined as a groove herein, the feature must have a depth in the thickness direction 24 that is greater than at least 50% of the depth of the first and second tread grooves 14, 16 in the thickness direction 24. These ornamental features need not engage only the circumferential feature 26. but could be located anywhere on the upper surface 66 of the tread 10.

[0040] The width 62 in various embodiments of the tread 10 can be between and including 25 to 75 millimeters. Preferably, the width 62 is between and including 35 to 65 millimeters. In some embodiments, the width 62 plus the distance 56 is between and including 45 millimeters to 130 millimeters. In other embodiments, the width 62 plus the distance 56 is between and including 50-120 millimeters, 60-110 millimeters, 70-100 millimeters, or 80-90 millimeters. The presence of the shoulder rib 36 avoids the design of having the high angle first and second tread grooves 14, 16 extend into the shoulder to weaken the design.

[0041] The tread 10 has been described in connection with the first and second tread grooves 14, 16, circumferential feature 26, and shoulder rib 36 that are located on the left hand side of the tread 10 in the lateral direction 22. It is to be understood that this description is for sake of convenience and that the right hand side of the tread 10 can feature first and second grooves, a circumferential feature, and a shoulder rib that are configured in similar manners as those of the left hand side as described above. The tread 10 can include a plurality of tread grooves 14, 16 and it is to be understood that the description focusing on just two of the tread grooves 14, 16 is for sake of convenience and that all of the tread grooves of the tread 10 can be configured in the same manner as that of the first or second tread groove 14, 16. Also, open grooves such as the first tread groove 14. second tread groove 16, and the circumferential feature 26 may be described as being rain grooves due to their ability to evacuate water. These grooves 14, 16, 26 may have widening at their bottoms in the thickness direction 24.

[0042] While the present subject matter has been described in detail with respect to specific embodiments and methods thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily produce alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the presentdisclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations and / or additions to the present subject matter as would be apparent.

Claims

CLAIMSWhat is claimed is:

1. A heavy truck tire tread, comprising: a first tread groove; a second tread groove; a rib located between the first tread groove and the second tread groove, wherein the first tread groove and the second tread groove define a pair of tread grooves, wherein the tread has a longitudinal direction, a lateral direction, and a thickness direction, wherein the pair of tread grooves and the rib are not oriented completely in the longitudinal direction so as to extend in both the longitudinal direction and the lateral direction; a circumferential feature; a first tread edge; a second tread edge, wherein a rolling tread width extends from the first tread edge to the second tread edge in the lateral direction, wherein a lateral midpoint of the tread is located halfway from the first tread edge to the second tread edge in the lateral direction; a shoulder rib that extends from the first tread edge to the circumferential feature; wherein the first tread groove and the second tread groove are located inboard from the circumferential feature in the lateral direction; wherein the first tread groove terminates in the tread at a first tread groove first terminal end that is inboard from both the shoulder rib and the circumferential feature such that the first tread groove does not engage the shoulder rib and such that the first tread groove does not engage the circumferential feature; and wherein the second tread groove terminates in the tread at a second tread groove first terminal end that is inboard from both the shoulder rib and the circumferential feature such that the second tread groove does not engage the shoulder rib and such that the second tread groove does not engage the circumferential feature.

2. The tread as set forth in claim 1, wherein the circumferential feature is a groove.

3. The tread as set forth in claim 1, wherein the circumferential feature is a sipe.

4. The tread as set forth in claims 2 or 3, wherein the circumferential feature has pin hole features at different locations along a longitudinal length of the circumferential feature.

5. The tread as set forth in any one of claims 1-4, further comprising lateral grooves that engage the circumferential feature, and wherein the lateral grooves are free from engagement with the first tread groove, and wherein the lateral grooves are free from engagement with the second tread groove.

6. The tread as set forth in any one of claims 1-5, further comprising a plurality' of sipes. wherein some of the plurality of sipes are located in the rib and engage both the first tread groove and the second tread groove, wherein some of the plurality of sipes engage both the circumferential feature and the first tread groove, and wherein some of the plurality of sipes engage both the circumferential feature and the second tread groove.

7. The tread as set forth in any one of claims 1-6, wherein the first tread groove has a first tread groove second terminal end, and wherein a first tread groove reference line extends from the first tread groove first terminal end to the first tread groove second terminal end, and wherein a first lateral line extends through the first tread groove first terminal end and is oriented completely in the lateral direction; wherein a first tread groove angle is measured from the first lateral line to the first tread groove reference line and is oriented towards the lateral midpoint; and wherein the first tread groove angle is from and including 40 degrees to 85 degrees.

8. The tread as set forth in claim 7, wherein the first tread groove angle is from and including 50 degrees to 75 degrees.

9. The tread as set forth in any one of claims 1-8. wherein the first tread groove first terminal end is the part of the first tread groove that is closest to the circumferential feature, and wherein the first tread groove first terminal end is spaced a distance that is from and including 5 millimeters to 60 millimeters in the lateral direction to the circumferential feature.

10. The tread as set forth in claim 9, wherein the first tread groove first terminal end is spaced a distance that is from and including 20 millimeters to 30 millimeters in the lateral direction to the circumferential feature.

11. The tread as set forth in any one of claims 1-10, wherein the shoulder rib does not have any grooves therein.

12. The tread as set forth in any one of claims 1-11, wherein the shoulder rib has a plurality of shoulder sipes therein that engage both the first tread edge and the circumferential feature, wherein the tread has a rolling direction in the longitudinal direction and wherein the shoulder sipes extend from the circumferential feature to the first tread edge so as to have a component of extension in the longitudinal direction that is in the same direction as the rolling direction.

13. The tread as set forth in any one of claims 1-11, wherein the first tread groove is an open groove and is straight from the first tread groove first terminal end to the first tread groove second terminal end; wherein the second tread groove is an open groove and is straight from the second tread groove first terminal end to a second tread groove second terminal end.

14. The tread as set forth in any one of claims 1-13. wherein a width of the shoulder rib is the distance of the shoulder rib in the lateral direction from the first tread edge to the circumferential groove, and wherein the width of the shoulder rib is greater than the distance from the first tread groove first terminal end to the circumferential feature in the lateral direction.

15. A heavy truck tire that has the tread of any one of claims 1-14.

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