Truck tire having high angle grooves spaced from shoulder bars

Abstract

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

Description

[0001] Statement regarding federally funded research or development

[0002] This invention was completed with government support under the Vehicle Technology Program funded by the Office of Energy Efficiency and Renewable Energy (EERE) of the U.S. Department of Energy (grant number DE-EE0009857). The government holds certain rights to this invention. Technical Field

[0003] The subject of this invention relates to a truck tire tread having inclined tread grooves arranged to prevent irregular wear. More specifically, this application relates to a truck tire tread characterized by inclined tread grooves that are spaced apart from and do not engage with circumferential features defining shoulder tread strips, in order to better manage erosive and irregular wear performance. Background Technology

[0004] Heavy-duty commercial vehicle tire manufacturers have made significant progress in developing tire structures and materials, enabling them to improve tire tread wear resistance, reduce rolling resistance, and simultaneously enhance grip and resistance to road hazards. Tread patterns can comprise a series of circumferential grooves with a series of circumferential slats interspersed therebetween. It can also be described as a longitudinal circumferential direction extending around the tire's central axis and oriented at a 90-degree angle relative to the tire's lateral direction. The circumferential grooves and slats extend 360 degrees around the tire and are oriented such that they have an extension component in the longitudinal / circumferential direction but no extension component in the lateral direction. Variations in tread patterns involve orienting the slats and grooves so that they are not circumferential slats and grooves, but instead include an extension component in the lateral direction. In this respect, tread grooves and slats may extend inward in the lateral direction from the shoulder edge while extending a certain amount in the longitudinal direction, resulting in an "oblique" orientation of these tread features.

[0005] Compared to tread designs that only include circumferential grooves and spurs, the use of angled spurs and grooves offers some advantages. However, the use of angled grooves and spurs causes wear zones on the outer edges of the spurs to occur at a faster rate than other areas of the spur and can propagate inwards. This results in sections of the tire that wear faster than the rest or areas with irregular wear, leading to tire owner complaints, decreased tire performance, and even premature tire discontinuation. In this regard, as high-angle grooves transition into the shoulder area of ​​the tread, they create small tread features or tread features with very sharp angles. These small features or sharp-angled features will serve as initiation points for irregular wear. One way to address this problem is to drastically reduce the angle of the angled grooves as they approach the shoulder area. This method can...Figure 1 As seen in the prior art design, the sloping tread grooves change angle at the tire shoulder, so that they are no longer perfectly linear in shape. However, this method requires the sloping tread grooves to change angle and extend towards the tire shoulder, thus limiting the types of tire shoulder and tread groove designs that can be used. These designs may still suffer from having small or sharp tread features. Therefore, there is still room for modification and improvement in the art. Attached Figure Description

[0006] Referring to the accompanying drawings, the complete and feasible disclosure of the invention for those skilled in the art, including its best mode, is set forth in the specification, wherein:

[0007] Figure 1 This is a perspective view of a heavy-duty truck tire using existing technology.

[0008] Figure 2 This is a top view of the tire tread according to an exemplary embodiment.

[0009] Figure 3 This is a top view of the tire tread according to another exemplary embodiment.

[0010] Figure 4 It is along Figure 3 The sectional view taken from line 4-4 in the figure.

[0011] Figure 5 This is a top view of the tire tread according to another exemplary embodiment.

[0012] Figure 6 It is along Figure 5 The sectional view taken from line 6-6 in the figure.

[0013] Figure 7 It is along Figure 5 The sectional view taken from line 7-7 in the figure. Detailed Implementation

[0014] Reference will now be made in detail to embodiments of the invention, with one or more examples of embodiments illustrated in the accompanying drawings. Each example is provided to illustrate the invention and is not intended to limit the invention. For example, features illustrated or described as part of one embodiment may be used with another embodiment to obtain a third embodiment. The invention is intended to include these and other modifications and variations.

[0015] The present invention provides a tread 10 for a heavy-duty truck tire 12, the tread having inclined grooves 14, 16 and slats 18, and a shoulder tread slat 36. The shoulder tread slat 36 extends from the tread edge 28 to a circumferential feature 26 of the tread 10, which may be, for example, a sipe or groove. A first tread groove 14 is spaced apart from and does not engage with the circumferential feature 26. This arrangement prevents the formation of very small tread features and / or tread features with very sharp angles in this region of the tread 10. Eliminating these small sharp features improves the tread 10's resistance to erosive damage and irregular wear. The provided arrangement also allows for greater flexibility in the design of the shoulder tread slat 36, such as a solid, sipe-grooved, or blocky shoulder tread slat with lateral grooves 44.

[0016] Figure 1 An existing tire 12 is shown, which is a heavy-duty truck tire 12. At this point, tire 12 is not designed or intended for automobiles, motorcycles, or light trucks (with a payload capacity of less than 4,000 pounds), but rather for heavy-duty trucks such as 18-wheelers, garbage trucks, or box trucks. Tire 12 can be a steering tire, drive tire, trailer tire, or all-position tire. Tire 12 includes a carcass 64 on which a tread 10 is disposed. Tread 10 can be manufactured and formed together with carcass 64 as a new tire 12, or tread 10 can be a retreading strip attached to carcass 64 at some point after carcass 64 has been used to form a retreaded tire 12. This is the case for all designs shown and described herein. They can all be tread designs for brand new tires 12, or they can be tread designs for tread 10 used in retreaded tires 12. The central axis of tire 12 extends through the center of carcass 64, and the lateral direction 22 of tire 12 is parallel to the central axis. The radial direction 24 (also referred to as the thickness direction 24) of tire 12 is perpendicular to the central axis, and the tread 10 is positioned in the thickness direction 24 further away from the central axis than the tire carcass 64. The tread 10 extends around the tire carcass 64 in the circumferential direction 20 (also referred to as the longitudinal direction 20) of tire 12 and is circumferentially 360 degrees around the central axis. The tread 10 includes a series of tread grooves and tread strips forming the tread pattern. The rolling tread width 32 extends in the lateral direction 22 from one shoulder edge 28 of the tread 10 to the opposite shoulder edge 30 of the tread 10. The rolling tread width 32 represents the portion of the tread 10 that engages the ground during normal operation of tire 12, and the area in the lateral direction 22 where the shoulder edges 28, 30 engage the ground and the area between these locations.

[0017] Figure 2This is a top view of the tread 10, which may be part of the tire 12 or a retreading strip, the tread being manufactured and subsequently attached to the tire carcass 64 to form a retreaded tire 12. The same tread pattern may be repeated along the entire longitudinal length of the tread 10. The tread 10 has a first tread groove 14 and a second tread groove 16, which are sequentially adjacent to each other in the longitudinal direction 20. The grooves 14, 16 may have various shapes and a width that may be equal to or greater than 2 mm. The shape of the central portion of the grooves 14, 16 may differ from the shape of the shoulder portion of the grooves 14, 16, or the shapes of the grooves 14, 16 may be the same along their entire depth in the thickness direction 24. A tread strip 18 is defined between the grooves 14, 16 in the longitudinal direction 20. The tread strip 18 is not a circumferential tread strip because, when part of the tire 12, it does not extend continuously around the tread 10 in the longitudinal direction 20. Instead, the tread strip 18 extends from the circumferential edge 26 to the center of the tread 10. Tread strip 18 is inclined relative to the longitudinal direction 20, such that tread strip 18 extends to have an extension component in both the longitudinal direction 20 and the lateral direction 22. In contrast, circumferential tread strips will have an extension component in the longitudinal direction 20 but no extension component in the lateral direction 22. The lateral midpoint 34 of the tread 10 is located at the midpoint between the first tread edge 28 and the second tread edge 30 in the lateral direction 22. Although shown at the lateral midpoint 34, tread grooves 14, 16 may be shorter than or longer than the lateral midpoint 34, and in other embodiments may be connected to each other or not connected. Various tread grooves 14, 16 are shown intersecting with groups on the other lateral half of the tread 10, but this is also unnecessary in other embodiments, as tread grooves 14, 16 and tread grooves on the opposite lateral side may interlock to form a single tread groove.

[0018] The first tread groove 14 and the second tread groove 16 are also not circumferential grooves because they extend in a manner that has an extension component in both the longitudinal direction 20 and the lateral direction 22. Grooves 14, 16 are spaced apart from and do not engage with the tread edges 28, 30 and the circumferential features 26, and extend to terminate at the center of the tread 10. Grooves 14, 16 may extend to and engage the lateral midpoint 34, and may actually pass through the lateral midpoint 34 to reach the opposite lateral half of the tread 10. Similarly, tread strip 18 may engage the lateral midpoint 34 or extend beyond the lateral midpoint to reach the opposite lateral half of the tread 10. In other embodiments, grooves 14, 16 and tread strip 18 do not need to extend to and engage the lateral midpoint 34. Grooves 14, 16 are isolated because they do not engage with any other grooves on the tread 10. However, in other arrangements, tread grooves 14 and 16 can engage with other tread grooves of the tread 10. In other arrangements, tread strip 18 can also engage with other tread strips of the tread 10.

[0019] The grooves 14 and 16 and the stripe 18 are straight and do not change their extension components along their length in the longitudinal direction 20 and the transverse direction 22, as shown below. Figure 2 As shown. In other embodiments, the grooves 14, 16 and the stripe 18 may have different extension components in the transverse direction 20 and the longitudinal direction 22 at one or more points along their entire length. This will cause the grooves 14, 16 and the stripe 18 to be inclined relative to the longitudinal direction 20. In other arrangements, the grooves 14, 16 and the stripe 18 may be curved along their length or have two, three, four or more angular changes.

[0020] The shape and size of the first tread groove 14 are set to be the same as those of the second tread groove 16, and they may have the same cross-sectional shape and size. In the illustrated embodiment, the extensions of the first tread groove 14 and the second tread groove 16 are both linear. The first groove 14 has a first tread groove first end 38, which is the portion of the first tread groove 14 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 end 48, which is located at the end of the first groove 14 opposite to the first tread groove first end 38. To describe the inclined orientation of the first tread groove 14, a first lateral line 52 extends through the first tread groove first end 38 and has no extension component in the longitudinal direction 20. The first tread groove reference line 50 extends through both the first end 38 and the second end 48 of the first tread groove. The first tread groove angle 54 is defined between the first lateral line 52 and the first tread groove reference line 50, and is oriented toward the lateral midpoint 34 so as to face and connect to and engage the lateral midpoint 34, such that the lateral midpoint 34 is within the first tread groove angle 54.

[0021] The first tread groove angle 54 can be 40 to 85 degrees, 45 to 80 degrees, 50 to 75 degrees, 55 to 70 degrees, 60 to 65 degrees, 40 to 45 degrees, 45 to 50 degrees, 50 to 55 degrees, 55 to 60 degrees, 60 to 65 degrees, 65 to 70 degrees, 70 to 75 degrees, 75 to 80 degrees, 80 to 85 degrees, 40 to 50 degrees, 50 to 60 degrees, 60 to 70 degrees, or 70 to 85 degrees, including the end values. Preferably, the first tread groove angle 54 is 50 to 75 degrees, including the end values. In other arrangements, the first tread groove angle 54 is 55 to 70 degrees, 60 to 67 degrees, 61 to 68 degrees, 62 to 66 degrees, or 58 to 73 degrees, including the end values.

[0022] Tread strip 18 is located between the first tread groove 14 and the second tread groove 16, and can extend along the innermost side of grooves 14 and 16 and terminate at that inner side. Tread strip 18 can also be considered to terminate at the groove where grooves 14 and 16 intersect near the center of the tread 10, but this intersecting groove is not at... Figure 2 As shown in the diagram. Furthermore, in some embodiments, the pattern strip 18 may extend beyond the pattern grooves 14 and 16 in both the transverse direction 22 and the longitudinal direction 20, until the pattern strip 18 terminates at an additional pattern groove or at the circumferential feature 26, such as... Figure 2 As shown. While the tread strip 18 extends primarily in the longitudinal direction 20, it also extends considerably in the lateral direction 22. Relative to the rolling tread width 32, the tread strip 18 extends at least 30% of the length of the rolling tread width 32 in the lateral direction 22. Thus, the tread strip 18 extends across at least 30% of the width of the rolling tread width 32 of the tire 12. However, in other embodiments, the tread strip 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 20% to 29% of the width of the rolling tread width 32. Similarly, the tread grooves 14 and / or 16 may extend across at least 30% of the length of the rolling tread width 32, and in other embodiments may extend 20% to 29% of the length of the rolling tread width 32.

[0023] The second tread groove 16 can be inclined in the same manner as the first tread groove 14, and this information need not be repeated. The orientation of the inclination of the second tread groove 16 can be exactly the same as that of the first tread groove 14, or it can be different from the orientation of the inclination of the first tread groove 14, but within a range as previously discussed. The size and shape of the second tread groove 16 can be set to be exactly the same as that of the first tread groove 14, or the two grooves 14, 16 can be different from each other.

[0024] The tread 10 is characterized by a circumferential feature 26 that forms the boundary of the shoulder tread strip 36 of the tread 10. The circumferential feature 26 may be a continuous feature extending completely 360 degrees around the central axis of the tire 12. Alternatively, the circumferential feature 26 may be a discontinuous feature that is not completely continuous 360 degrees around the tire 12, but has discontinuous portions at various locations around the 360 ​​degrees. Figure 2The circumferential feature 26 is an open tread groove. As described herein, a tread groove is an opening greater than 2 mm in the upper surface 66 that extends to a certain depth in the tread 10 in the thickness direction 24. The first tread groove 14 and the second tread groove 16 are spaced apart from the circumferential feature 26 and do not engage with it. In this respect, the first tread groove 14 and the second tread groove 16 are spaced apart from the circumferential feature 26 in the transverse direction 22. The first end 38 of the first tread groove is the portion of the first tread groove 14 that is closest to the circumferential feature 26 in the transverse direction 22.

[0025] The first end 38 of the first tread groove is spaced 56 from the circumferential feature 26, as measured only in the lateral direction 22. This distance 56 is measured to the point where the circumferential feature 26 begins, and the first end 38 of the first tread groove can be the portion of the first tread groove 14 at the lateral extent that is closest to that portion of the circumferential feature 26. If the circumferential feature 26 is serrated, inclined, or wavy, the distance 56 is measured entirely in the lateral direction 22 from the first end 38 of the first tread groove until it first encounters the circumferential feature 26, even if other portions of the circumferential feature 26 are more inward in the lateral direction 22 than that point. The distance 56 can be between 5 mm and 50 mm, including the end value, and is preferably between 20 mm and 30 mm, including the end value. In other embodiments, the distance 56 is between 5 mm and 15 mm, 15 mm and 25 mm, 25 mm and 35 mm, 35 mm and 45 mm, 45 mm and 50 mm, 15 mm and 35 mm, 20 mm and 25 mm, 15 mm and 30 mm, 35 mm and 50 mm, 10 mm and 40 mm, 15 mm and 40 mm, 15 mm and 50 mm, 20 mm and 50 mm, 30 mm and 50 mm, 18 mm and 28 mm, 8 mm and 28 mm, 26 mm and 44 mm, 27 mm and 38 mm, 27 mm and 34 mm, or 28 mm and 33 mm, including the end values. In other embodiments, the distance 56 can be other distances and is selected such that the tread 10 is designed without small or sharp features formed by the intersection between the first tread edge 28 and the circumferential feature 26. Therefore, the listed value of distance 56 was chosen to be large enough to avoid sharp, pointed features in the tread 10, but small enough so as not to lose the benefit of water drainage from the steeply angled tread grooves 14, 16.

[0026] The second tread groove 16 has a first end 40, which is the portion of the second tread groove 16 that is closest to the circumferential feature 26 only when measured in the lateral direction 22. The first end 40 of the second tread groove does not engage with the circumferential feature 26 and is spaced apart from the circumferential feature in the lateral direction 22 by a certain distance. This spacing and distance can be the same as previously discussed with respect to distance 56, and this information does not need to be repeated. The spacing of the first ends 40 of the second tread groove can be the same distance as distance 56 between them and the circumferential feature 26, or the distance and distance 56 can be different from each other. The ends 38 and 40 can be located at the same position in the tread 10 in the lateral direction 22. The ends 38 and 40 can be spaced apart from each other by a greater distance than distance 56 in the longitudinal direction 20.

[0027] Therefore, the first tread groove 14 and the second tread groove 16, as well as all tread grooves of the tread 10 in this and other embodiments, are spaced apart from and do not engage with the circumferential feature 26. This spacing avoids the need for the first tread groove 14 and the second tread groove 16 to be inclined as they approach their exits to the tread edges 28, 30 or the shoulder tread strip 36. This spacing also avoids the need for the main rainwater grooves of the tread 10 to exit at the shoulder, allowing the tread 10 to be designed with shoulder tread strips 36, which can be solid tread strips, tread strips with small shoulder notches and shallow decorative elements, shoulder tread strips 36 with sipes, block shoulder tread strips 36, or any other type of shoulder tread strip 36. Thus, the offset in the lateral direction 22 allows for the provision of shoulder tread strips 36, which can be constructed differently to optimize the design or achieve other design flexibility. The shoulder tread strips 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 tread grooves 14, 16 in the lateral direction 22 relative to the circumferential features 26 allows for better management of the tread 10's aggressive and irregular wear performance over a wider range of applications for the tire 12. In addition to allowing for a range of shoulder tread strip designs 36, the spacing, as described herein, provides a more robust tread 10 in terms of tread aggressive damage and irregular wear. This design avoids the presence of small, sharp, or pointed tread blocks at the ends of the shoulders or rain grooves.

[0028] If the tread 10 rolls in a specific direction in the longitudinal direction 20, the tread 10 can be designed to have certain performance characteristics. This direction is referred to as the rolling direction 60 and is the direction of rotation of the tread 10 in the longitudinal direction 20, in which the tread 10 is designed to rotate to achieve the desired performance. Figure 2The tread 10 shown is a directional tread 10, and the features are arranged on the tread 10 to produce the desired performance characteristics in the rolling direction 60. The first tread groove 14 and the second tread groove 16 are arranged on the tread 10 such that the grooves 14, 16 extend inward in the lateral direction 22 and forward in the rolling direction 60.

[0029] The shoulder tread strip 36 is defined on one side of the tread 10 as the area between the first tread edge 28 and the circumferential feature 26. The shoulder tread strip 36 has a width 62, which is the distance in the lateral direction 22 extending from the first tread edge 28 to the circumferential feature 26. The width 62 is measured in the lateral direction 22 to the nearest portion of the circumferential feature 26. If the circumferential feature 26 is wavy, inclined, undulating, or otherwise does not have a single location in the lateral direction 22, the width 62 can be the width of the shoulder tread strip 36, which is the minimum width that can be measured at any longitudinal location of the shoulder tread strip 36. The shoulder tread strip 36 can be designed in any way and can be featureless or have various features formed therein. The shoulder tread strip 36 has lateral grooves 44 that extend completely from the first tread edge 28 to the circumferential feature 26, such that they engage 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, thus having the same depth in the thickness direction 24 as the first tread groove 14 and the second tread groove 16. The lateral grooves 44 are openings in the upper surface 66 and are wider than 2 mm. The lateral grooves 44 divide the shoulder tread strips 36 into a series of continuous tread blocks in the longitudinal direction 20. The lateral grooves 44 are oriented because as they extend forward in the longitudinal direction 20 in the same direction as the rolling direction 60, they extend inward in the lateral direction 22.

[0030] The tread 10 includes a plurality of sipes 46, which are openings in the upper surface 66 extending into the tread 10 in the thickness direction 24 and having a width of less than or equal to 2 mm. The sipes 46 can be described as castle-shaped sipes 46 because they have a support-like shape, but some of the sipes 46 are not support-like in shape and are straight. The sipes 46 engage both the first tread groove 14 and the second tread groove 16, such that the tread strip 18 has sipes 46 extending fully across its width. Some of the sipes 46 engage the circumferential feature 26 and extend from the circumferential feature to the first tread groove 14, but these sipes 46 do not engage the second tread groove 16. Other sipes in sipe 46 engage the circumferential feature 26 and the second tread groove 16, but not the first tread groove 14. Some sipes in sipe 46 are arranged in rows such that they extend from the circumferential feature 26 to the lateral midpoint 34 in a linear manner at an angle to the lateral direction 22, such that the row has an extension component in the longitudinal direction 20 opposite to the extension component in 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 an extension component in the longitudinal direction 20 that is in the same direction as the extension component in the rolling direction 60. Although the direction changes at the lateral midpoint 34, in other embodiments, the row of sipes 46 may alternatively change direction at a position close to but not exactly at the lateral midpoint 34, for example, at a position in the lateral direction 22 at a distance of ±30 mm from the lateral midpoint 34. The line then extends to the opposite circumferential feature 26 and terminates at that point. The sipe 46 is present along most of the rolling tread width 32 and exists between a pair of circumferential features 26, but the sipe 46 is not present in any of the shoulder tread strips 36.

[0031] Tread grooves 14 and 16 have been described as not engaging circumferential feature 26. Sipe 46 can actually engage tread grooves 14 and 16 and extend to engage circumferential feature 26. However, no groove is described as engaging both tread groove 14 and circumferential feature 26 with a width greater than 2 mm, and no groove engages both tread groove 16 and circumferential feature 26. Therefore, sipe 46 is a unique feature of the tread 10 and is not part of the first tread groove 14, the second tread groove 16, or any other tread groove in the tread pattern of the tread 10.

[0032] refer to Figure 3Another embodiment of the tread 10 is shown. The first tread groove 14 and the second tread groove 16 are again inclined so as to have extensional components in both the longitudinal direction 20 and the lateral direction 22, and are not fully open grooves from one end to the other, but partially open. See also... Figure 4 In the cross-sectional view, tread grooves 14 and 16 extend a certain length on the upper surface 66. These grooves are open grooves with a width greater than 2 mm, followed by closed sections, which can be sipes with a width of 2 mm or less. These closed and open sections alternate along the remaining length of the tread grooves 14 and 16. As the tread grooves 14 and 16 extend from the upper surface 66 into the tread 10, the widths of the tread grooves 14 and 16 alternate, such that they alternate between tread grooves and sipes. Half of the tread grooves 14 and 16 are wider than 2 mm, and the other half are 2 mm or less, depending on their position in the thickness direction 24. The first tread groove 14 and the second tread groove 16 are spaced apart from and do not engage with the circumferential feature 26. The distance 56 between the first tread groove 14 and the second tread groove 16 can be compared with the previously mentioned... Figure 2 The distances discussed in the tread grooves 14 and 16 of the implementation scheme are the same, and this information does not need to be repeated.

[0033] The first tread groove 14 and the second tread groove 16 extend to and engage with the lateral midpoint 34, and extend a certain distance into the opposite lateral half of the tread 10. The grooves 14 and 16 alternate, such that the continuous grooves 14 and 16 in the longitudinal direction 20 have alternating opening sections or sipe sections on the upper surface 66 closest to the circumferential feature 26. The tread grooves 14 and 16 have a depth in the thickness direction 24 that is two or three millimeters deeper than the depth of the sipe 46, but in some cases the depths of the grooves 14 and 16 and the sipe 46 may be all the same.

[0034] The groove pattern 46 is again configured to engage two circumferential features 26 and extend in rows from the two circumferential features, these rows moving away from the rolling direction 60 as they move inward toward the transverse midpoint 34. This groove pattern 46 is straight and does not have any castle-shaped features. The groove pattern 46 extends in a straight row positioned at an angle to the transverse direction 22 from the circumferential features 26, extending rearward in the longitudinal direction 20 in a direction opposite to the rolling direction 60. These rows engage with each other at the transverse midpoint 34, and in other cases engage with each other near the transverse midpoint, such as within 30 mm of the transverse midpoint 34 in the transverse direction 22.

[0035] The circumferential feature 26 is a groove pattern, which may or may not have a teardrop-shaped portion at its bottom. In fact, any groove pattern described herein may or may not have a teardrop-shaped portion at its bottom. The circumferential feature 26 extends entirely in the longitudinal direction 20 and does not have any angles, curves, or other features in any part of it that have an extension component in the transverse direction 22. The circumferential feature 26 has a pin hole feature 42 located at the intersection of the circumferential feature 26 and the groove pattern 46. The pin hole feature 42 is cylindrical and extends from the upper surface 66 to the same depth as the rest of the circumferential feature 26. The pin hole feature 42 has a diameter larger than the width of the groove pattern portion of the circumferential feature 26 and is joined not only by the groove pattern 46 but also by two of these groove pattern portions. The sipe 46 may have a depth extending from the upper surface 66 into the tread 10, the same depth as the remaining sipe portion of the pin hole feature 42 and the circumferential feature 26. The first tread groove 14 and the second tread groove 16 do not engage with the circumferential feature 26. When referred to as not engaging the circumferential feature 26, no groove engages both the circumferential feature 26 and the tread grooves 14, 16; rather, at most the sipe 46 engages these components. Thus, the sipe 46, as an opening with a width of 2 mm or less, is not considered to cause engagement between the circumferential feature 26 and the tread grooves 14, 16.

[0036] The shoulder tread strip 36 is featureless because it does not have any tread grooves or sipes and is a solid tread strip extending completely 360 degrees around the axis of the tire 12. The shoulder tread strip 36 has a width 62, which is measured along a direction entirely in the lateral direction 22 from the first tread edge 28 to the nearest contact point of the circumferential feature 26. If the first tread edge 28 is not perfectly linear in shape, but has a shoulder notch or is otherwise sloping or shaped such that it does not all have a single position in the lateral direction 22, then the width 62 is measured from the innermost portion of the first tread edge 28 in the lateral direction 22 that is closest to the lateral midpoint 34.

[0037] Reference Figures 5 to 7Another exemplary embodiment of the tread 10 is shown. In this embodiment, the first tread groove 14 and the second tread groove 16 are spaced apart from and do not engage with the circumferential feature 26. The distance 56 from the circumferential feature 26 to the first end 38 of the first tread groove and the distance from the circumferential feature 26 to the first end 40 of the second tread groove can be the same as previously discussed. The first tread groove 14 and the second tread groove 16 do not engage with any other grooves of the tread 10. As discussed herein, the various first tread grooves 14 and second tread grooves 16 may not be interconnected, such that they do not engage with each other or that no other groove engages them both. Alternatively, the first tread grooves 14 and the second tread grooves 16 may be interconnected via grooves, but these grooves will not engage with the circumferential feature 26. The sipes 46 that may exist in the tread 10 are not considered to connect the first tread groove 14 and the second tread groove 16 to each other or to the circumferential feature 26. The first tread groove 14 and the second tread groove 16 are open grooves and are not perfectly linear in their extension, but have a curved shape. To calculate the first tread groove angle 54, the ends 38 and 40 are marked again based on the point closest to the circumferential feature 26 in the lateral direction 22 and 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 and 40, and the first tread groove angle 54 is measured from the first lateral line 52 to the first tread groove reference line 50 so as to open toward the lateral midpoint 34. The size of the first tread groove angle 54 can be set as previously discussed.

[0038] There are no sipes 46 in the intermediate section of the tread 10 located between the pair of circumferential features 26. The circumferential features 26 are bridging open tread grooves. A bridging is a feature of the tread groove where the depth of the tread groove in the thickness direction 24 is not uniform along its entire length. Instead, at the discontinuities, the depth of the tread groove becomes shallower to create a greater connection between the two tread features 10 defining the tread groove. (Reference) Figure 6 and Figure 7 The cross-sectional view shows that the bridging portion 68 fills a portion of the depth of the circumferential feature 26, such that the circumferential feature 26 does not extend in the thickness direction 24 to the same depth as the shoulder sipes 58 or tread grooves at the location of the bridging portion 68, but actually extends in the thickness direction 24 to the same depth as the shoulder sipes 58 and tread grooves where the bridging portion 68 does not exist. The bridging portion 68 is not half the depth of the circumferential feature 26, but rather its thickness is less than half the height of the circumferential feature 26.

[0039] The shoulder tread strip 36 has no tread grooves, but has a series of shoulder sipes 58 extending from and joining both the first tread edge 28 and the circumferential feature 26. The portion of the circumferential feature 26 joined by the shoulder sipes 58 is the portion without the bridging portion 68, such that the shoulder sipes 58 do not engage the bridging portion 68. The shoulder sipes 58 are inclined relative to the longitudinal direction 20 so as to have extension components in both the longitudinal direction 20 and the lateral direction 22. The shoulder sipes 58 extend outward from the circumferential feature 26 toward the first tread edge 28 in the lateral direction 22 and have a forward extension component in the longitudinal direction 20, which is in the same direction as the rolling direction 60. The shoulder sipes 58 have the same depth in the thickness direction 24 as the first tread groove 14 and the second tread groove 16, and have the same depth as the portion of the circumferential feature 26 without the bridging portion 68. The first tread groove 14 and the second tread groove 16 may also include a bridging portion 68 in some embodiments.

[0040] The tread 10 may also include decorative features that resemble tread grooves or other elements that appear to allow the circumferential features 26 to communicate with the tread grooves 14, 16 or the tread edges 28, 30. These decorative features may have a width greater than 2 mm, but their depth is typically very shallow, making them primarily decorative rather than functional. Therefore, in order to be defined herein as a tread groove, the feature must have a depth in the thickness direction 24 that is at least 50% greater than the depth in the thickness direction 24 of the first tread groove 14 and the second tread groove 16. These decorative features need not only engage with the circumferential features 26, but can be located anywhere on the upper surface 66 of the tread 10.

[0041] In various embodiments of the tread 10, the width 62 may be between 25 mm and 75 mm, including the end values. Preferably, the width 62 is between 35 mm and 65 mm, including the end values. In some embodiments, the width 62 plus the distance 56 is between 45 mm and 130 mm, including the end values. In other embodiments, the width 62 plus the distance 56 is between 50 mm and 120 mm, 60 mm and 110 mm, 70 mm and 100 mm, or 80 mm and 90 mm, including the end values. The presence of the shoulder tread strip 36 prevents a design that would weaken the design by extending the high-angle first tread groove 14 and second tread groove 16 into the shoulder.

[0042] The tread 10 has been described in conjunction with the first tread groove 14 and the second tread groove 16, the circumferential feature 26, and the shoulder tread strip 36 located on the left-hand side of the tread 10 in the lateral direction 22. It should be understood that this description is for convenience, and the right-hand side feature of the tread 10 may be constructed in a similar manner to the left-hand side as described above. The tread 10 may include multiple tread grooves 14, 16, and it should be understood that the description focusing only on two of the tread grooves 14, 16 is for convenience, and all tread grooves of the tread 10 may be constructed in the same manner as the first tread groove 14 or the second tread groove 16. Furthermore, open grooves such as the first tread groove 14, the second tread groove 16, and the circumferential feature 26 can be described as rainwater grooves due to their drainage capacity. These grooves 14, 16, and 26 may have a widened portion at their bottom in the thickness direction 24.

[0043] Although the subject matter of the invention has been described in detail with respect to specific embodiments and methods, it should be understood that modifications, variations, and equivalents of such embodiments can be readily conceived by those skilled in the art upon understanding the foregoing. Therefore, the scope of this disclosure is by way of example rather than limitation, and this disclosure does not exclude obvious such modifications, variations, and / or additions to the subject matter.

Claims

1. A heavy-duty truck tire tread, the heavy-duty truck tire tread comprising: First tread groove; Second tire tread grooves; Tread strip, the tread strip being 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 transverse direction and a thickness direction, wherein the pair of tread grooves and the tread strip are not oriented entirely in the longitudinal direction, thereby extending in both the longitudinal direction and the transverse direction. Circumferential feature section; First tread edge; The second tread edge, wherein the rolling tread width extends from the first tread edge to the second tread edge in the lateral direction, wherein the lateral midpoint of the tread is located in the lateral direction between the first tread edge and the second tread edge; Shoulder tread strips, which extend from the edge of the first tread to the circumferential feature; The first tread groove and the second tread groove are located inside the circumferential feature in the transverse direction; The first tread groove terminates in the tread at its first end, and the first end of the first tread groove is inside both the shoulder tread strip and the circumferential feature portion, such that the first tread groove does not engage with the shoulder tread strip and the circumferential feature portion; and The second tread groove terminates in the tread at its first end. The first end of the second tread groove is inside both the shoulder tread strip and the circumferential feature, such that the second tread groove does not engage with the shoulder tread strip and does not engage with the circumferential feature.

2. The tread according to claim 1, wherein the circumferential feature is a tread groove.

3. The tread according to claim 1, wherein the circumferential feature is a sipe pattern.

4. The tread according to claim 2 or 3, wherein the circumferential feature has pin hole features at different positions along the longitudinal length of the circumferential feature.

5. The tread according to any one of claims 1 to 4, the tread further comprising a transverse tread groove engaging the circumferential feature, wherein the transverse tread groove does not engage with the first tread groove, and wherein the transverse tread groove does not engage with the second tread groove.

6. The tread according to any one of claims 1 to 5, wherein the tread further comprises a plurality of sipes, wherein some of the plurality of sipes are located in the tread strip 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 according to any one of claims 1 to 6, wherein the first tread groove has a second end of the first tread groove, and wherein the reference line of the first tread groove extends from the first end of the first tread groove to the second end of the first tread groove, and wherein the first lateral line extends through the first end of the first tread groove and is oriented entirely in the lateral direction; The first tread groove angle is measured from the first lateral line to the first tread groove reference line and is oriented towards the midpoint of the lateral line; and The first tread groove angle is 40 degrees to 85 degrees, including the end value.

8. The tread according to claim 7, wherein the first tread groove angle is 50 degrees to 75 degrees and includes the end value.

9. The tread according to any one of claims 1 to 8, wherein the first end of the first tread groove is the portion of the first tread groove closest to the circumferential feature, and wherein the first end of the first tread groove is spaced 5 mm to 60 mm from the circumferential feature in the transverse direction, including the end value.

10. The tread according to claim 9, wherein the first end of the first tread groove is spaced 20 mm to 30 mm from the circumferential feature in the transverse direction, including the end value.

11. The tread according to any one of claims 1 to 10, wherein the shoulder tread strip does not have any tread grooves.

12. The tread according to any one of claims 1 to 11, wherein the shoulder tread strip has a plurality of shoulder sipes therein, the plurality of shoulder sipes joining 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 to have an extension component in the longitudinal direction, the extension component being in the same direction as the rolling direction.

13. The tread according to any one of claims 1 to 11, wherein the first tread groove is an open groove and is straight from the first end of the first tread groove to the second end of the first tread groove; The second tread groove is an open groove and is straight from the first end of the second tread groove to the second end of the second tread groove.

14. The tread according to any one of claims 1 to 13, wherein the width of the shoulder tread strip is the distance of the shoulder tread strip from the edge of the first tread to the circumferential tread groove in the transverse direction, and wherein the width of the shoulder tread strip is greater than the distance from the first end of the first tread groove to the circumferential feature in the transverse direction.

15. A heavy-duty truck tire having a tread according to any one of claims 1 to 14.

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