Truck tire with angled grooves and blocking SIPE for irregular wear

Abstract

A heavy truck tire tread is provided that has first (26) and second (30) grooves that extend in both the longitudinal and lateral directions, and are free from engagement with the left and right side edges. A shoulder sipe (64) extends from the left side edge to the second groove and is free from engagement with the first groove. A blocking sipe (36) engages a first groove terminal end and extends to, and into engagement with, the shoulder sipe. The blocking sipe is free from engagement with the second groove, and extends a greater distance in the longitudinal direction than in the lateral direction.

Description

TRUCK TIRE WITH ANGLED GROOVES AND BLOCKING SIPE FOR IRREGULARWEARSTATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0001] This invention was made with government support under the grant program for Renewable Energy Research and Development having Award Number DE-EE0009857 awarded by the U.S. Department of Energy’s (DOE) National Energy Technology Lab (NETL) with the funding agency being the 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 that has a tread design that seeks to improve resistance to irregular wear. More particularly, the present application involves a tread design that features a blocking sipe that acts as a break in the propagation of irregular wear so that irregular wear extending inboard from a side edge of the tread is stopped once it propagates to the blocking sipe.BACKGROUND OF THE INVENTION

[0003] Manufacturers of heavy commercial vehicle tires have made huge progress in developing tire architectures and tire materials that allow them to increase the wear resistance of tire treads and reduce the rolling resistance of tires while at the same time improving their level of grip and resistance to road hazard. However, designing a tire to perform well in one category may cause it to perform worse in another category. For example, designing a tire with low rolling resistance for improved fuel efficiency may have the trade-off of having reduced traction and reduced wear life. Tires may suffer from localized irregular wear zones in which some portions of the tire tread wear faster than others causing a noticeable wear section at certain spots on the tire, while other portions of the tread look fine without this increased wear. These irregular wear zones can result in customer dissatisfaction and may even lead to early removal of the tire from service. These areas of abnormal wear tend to originate at the exterior edge of shoulder ribs and propagate inwards towards the interior.

[0004] It is known to provide tread designs that feature ribs at an angle to the longitudinal direction so that they do not extend completely 360 degrees around the tire. The ribs can extend from the shoulders toward the center and may terminate at the center or may terminate at another rib in the tread design. An example of a tire tread that utilized angled grooves and ribs may be seen with reference to Patent Cooperation Treaty publication number WO 2020 / 102056, the entire contents of which are incorporated by reference herein in their entirety for all purposes. The use of high angled ribs and grooves provide improved traction, wear resistance, and aggression resistance. However as discussed, improving some performance features of the tire may cause other performance features to be impacted and perform worse. Tires with high angled ribs and grooves, that lack a shoulder groove, may develop irregular wear at the shoulder edges that moves inboard in the lateral direction. Irregular wear may be seen on these types of tires that have shoulder ribs that have sipes in them. Stopping the propagation of irregular wear across the tread may result in improved customer satisfaction and potentially increase milage before the tire is removed from service. 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. l is a perspective view of a heavy truck tire with blocking sipes.

[0007] Fig. 2 is a front view of a portion of the tread of the tire of Fig. 1.

[0008] Fig. 3 is front view of a portion of tread that features a blocking sipe that terminates at a first shoulder sipe.

[0009] Fig. 4 is a front view of a portion of tread that has blocking sipes with micro sipes that extend outboard therefrom.

[0010] Fig. 5 is a front view of a portion of tread that has blocking sipes with micro sipes that extend inboard therefrom.

[0011] Fig. 6 is a front view of a portion of tread that has blocking sipes that extend outboard as they extend downward in the thickness direction away from the upper surface.

[0012] Fig. 7 is a cross-sectional view taken along line 7-7 of Fig. 6

[0013] Fig. 8 is a front view of a portion of tread that has blocking sipes that extend inboard as they extend downward in the thickness direction away from the upper surface.

[0014] Fig. 9 is a front view of a portion of tread that has blocking sipes that terminate at the first shoulder sipe and that have a teardrop.

[0015] Fig. 10 is a cross-sectional view taken along line 10-10 of Fig. 9.

[0016] Fig. 11 is a front view of a portion of tread that has blocking sipes that terminate at a second shoulder sipe and that extend in both the longitudinal and lateral directions.

[0017] The use of identical or similar reference numerals in different figures denotes identical or similar features.DETAILED DESCRIPTION OF THE INVENTION

[0018] 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.

[0019] The present invention provides for a tread 10 for a tire 5 that decreases the amount of abnormal wear imparted onto the tread 10 through the use of design elements. The tread 10 features a first groove 26 and a second groove 30 that have components of extension in the tread 10 in both the longitudinal and lateral directions 12, 14. Both of the grooves 26, 30 are spaced from and free from engagement with the edges 20, 22 of the tread 10. The grooves 26, 30 are oriented in such a manner that they have components of extension that are not completely in the longitudinal direction 12, but rather are in both the longitudinal direction 12 and the lateral direction 14. A series of shoulder sipes 34, 42 extend from the edges 20, 22 of the tread 10 inboard in the lateral direction 14. Blocking sipes 36 extend from terminal ends 28 of the grooves 26, 30 and are oriented more in the longitudinal direction 12 than in the lateral direction 14. These blocking sipes 36 intersect at least one of the shoulder sipes 34 and function to prevent the propagation of abnormal wear inboard across the shoulder of the tread 10 towards the interior in the lateral direction 14.

[0020] Figs. 1 and 2 show a tire 5 that is a heavy duty truck tire 5. In this regard, the tire 5 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 5 may be a steer tire, a drive tire, a trailertire, or an all position tire. The tire 5 includes a casing onto which a tread 10 is disposed. The tread 10 can be manufactured with the casing and formed as a new tire 5, or the tread 10 can be a retread band that is attached to the casing at some point after the casing has already been used to form a retreaded tire 5. This is the case with all of the designs shown and described herein. They may all be tread designs of a brand new tire 5, or may be tread designs of a tread 10 for use in a retread tire 5. The central axis 60 of the tire 5 extends through the center of the casing, and the lateral direction 14 of the tire 5 is parallel to the central axis 60. The radial direction 16, referred to also as the thickness direction 16, of the tire 5 is perpendicular to the central axis 60 and the lateral direction 14, and the tread 10 is located farther from the central axis 60 in the thickness direction 16 than the casing. The tread 10 extends all the way around the casing of the tire 5 in the circumferential direction 12, also referred to as the longitudinal direction 12, of the tire 5 and circles the central axis 60 completely 360 degrees. The tread 10 includes a series of grooves and ribs that form a tread pattern. A rolling tread width 24 extends in the lateral direction 14 from the left side edge 20 of the tread 10 to an opposite right side edge 22 of the tread 10. The rolling tread width 24 represents that portion of the tread 10 that engages the ground through normal operation of the tire 5, and the shoulder edges 20, 22 may engage the ground as well as the area between these locations in the lateral direction 14. The center of the tread 10 is the location of the tread 10 at the lateral midpoint, halfway between the shoulder edges 20, 22 in the lateral direction 14.

[0021] The tread 10 is directional in that it is designed for forward rotation of the tire 5. The rolling direction 62 is the direction in the longitudinal direction 12 the tread 10 is designed to rotate. The entire tread 10 going around the tire 5 can be directional so that it is designed to roll in one direction to achieve desired rolling performance in this one direction 62. The tread 10 may still rotate in the opposite direction from the desired rolling direction 62, but may not experience the designed for performance in this direction. Although the tread 10 has been described as being directional, it need not be directional in accordance with other exemplary embodiments. The configuration of the various grooves 26, 30 such that they extend inboard in the lateral direction 14 and toward one another at the lateral midpoint may make the tread 10 a directional tread 10 such that it performs a desired way when rotating in the rolling direction 62.

[0022] The tread grooves 26, 30 can be variously shaped and have widths that can be greater than 2 millimeters. A first groove 26 and a second groove 30 are identified, but itis to be understood that grooves of this type can be positioned completely around the entire circumference of the tire 5 in the longitudinal direction 12. The grooves 26, 30 are oriented so as to extend both in the longitudinal direction 12 and the lateral direction 14, although the grooves 26, 30 have a greater component of extension in the longitudinal direction 12 than its component of extension in the lateral direction 14. The grooves 26, 30 are straight in that they extend in a straight direction without changing angles, and are oriented at an angle to the longitudinal direction 12. The grooves 26, 30 are blind in that the grooves do not engage other grooves on the tread 10, although sipes may extend so as to engage multiple grooves 26, 30 of the tread 10 in other embodiments. The grooves 26, 30 do not extend completely 360 degrees around the entire circumference of the tire 5 in the longitudinal direction 12. The grooves 26, 30 can have a wavy shape or a curved shape in other embodiments, and can have cross-sectional shapes that are of any shape. Further, the cross-sectional shape of the grooves 26, 30 need not be consistent along their entire lengths but can be different at different areas of the grooves 26, 30. The grooves 26, 30 are spaced from and free from engagement with the left side edge 20. Further, the grooves 26, 30 are spaced from and free from engagement with the right side edge 22, and no grooves in the tread 10 engage either the left or right side edges 20, 22. The tread 10 does not have a shoulder groove that is circumferential that extends completely around the entire circumference of the tire 5 in the longitudinal direction 12.

[0023] The first groove 26 is oriented at an angle 38 to the lateral direction 14 such that the first groove 26 has components of extension in both the longitudinal direction 12 and the lateral direction 14. The second groove 30 likewise is oriented at an angle 40 to the lateral direction 14 so that the second groove 40 has a component of extension in both the longitudinal direction 12 and the lateral direction 14. The angles 38 and 40 may be the same as one another or can be different from one another. The angles 38 and / or 40 may be from 15 degrees to 50 degrees, 30 degrees, from 20 degrees to 45 degrees, from 25 degrees to 40 degrees, from 30 degrees to 35 degrees, or from 10 degrees to 25 degrees. Still further, the angles 38 and / or 40 may be from 25 degrees to 50 degrees, from 25 degrees to 35 degrees, from 25 degrees to 70 degrees, or from 30 degrees to 60 degrees to the longitudinal direction 12 in other exemplary embodiments. The rib 32 may also be arranged at any of the aforementioned angles 38 and / or 40 with respect to the longitudinal direction 12. When the grooves 26 and 30 are straight, the angles 38 and 40 can be calculated as shown in Fig. 2 by measuring the angle between the longitudinal direction 12 and the center length of thegrooves 26 and 30. When the grooves 26 and 30 have one or more changes of direction or are curved, the angles 38 and 40 can be calculated by drawing a line from the end of the groove 26 / 30 that is most outboard in the lateral direction 14 to the opposite end. The angle 38 / 40 can then be measured between this line and the longitudinal direction 12. As can be seen, angles 40, 38 that are 0 degrees represent grooves that are circumferential in orientation and thus run completely in the longitudinal direction 12 with no component in the lateral direction 14.

[0024] A rib 32 is defined between the tread grooves 26, 30 in the longitudinal direction 12. The rib 32 is not a circumferential rib in that it does not extend all the way around the tread 10 in the longitudinal direction 12. Instead, the rib 32 extends from the lateral midpoint to a position spaced from the left side edge 20. The rib 32 is angled relative to the longitudinal direction 12 so that the rib 32 extends to have a component of extension in both the longitudinal direction 12 and in the lateral direction 14. In contrast, a circumferential rib would have a component of extension in the longitudinal direction 12 and no component of extension in the lateral direction 14. The rib 32 is not a circumferential rib in that it does not extend all the way around the tread 10 in the longitudinal direction 12. A circumferential rib would have a component of extension in the longitudinal direction 12 and no component of extension in the lateral direction 14 so as to be completely oriented in the longitudinal direction 12.

[0025] In some embodiments, certain grooves do in fact open at and engage and then extend from the left or right side edge 20, 22 to the center of the tread 10. The tread grooves may engage other grooves of the tread 10, and the ribs between the tread grooves may engage other ribs of the tread 10 in other arrangements. However, in these alternate embodiments there will still be a first and second groove 26, 30 that are spaced from and free from engagement with both the left side edge 20 and the right side edge 22. The tread grooves and ribs may have different components of extension in the longitudinal and lateral directions 12, 14 along their lengths and their angles change once, or multiple times.

[0026] The spacing of the grooves 26, 30 to the nearest tread edge 20, 22 may be at least 5 millimeters, at least 7 millimeters, at least 10 millimeters, at least 12 millimeters, at least 15 millimeters, at least 17 millimeters, at least 20 millimeters, at least 25 millimeters, at least 30 millimeters, at least 35 millimeters, at least 40 millimeters, at least 60 millimeters, at least 70 millimeters, at least 80 millimeters, at least 90 millimeters, at least 100 millimeters, at least 125 millimeters, or at least 150 millimeters in accordance with variousexemplary embodiments. Applicants have discovered that spacing the grooves 26, 30 from the tread edges 20, 22 increases the performance improvements previously mentioned. The grooves 26, 30 on the left hand side of the tread 10 can be configured in the same manner as those on the right hand side such that they are spaced from and not in engagement with either of the side edges 20, 22

[0027] The tread 10 has a plurality of shoulder sipes, such as a first shoulder sipe 34 and a second shoulder sipe 42. The shoulder sipes 34, 42 engage the left side edge 20 and extend from the left side edge 20 to and into engagement with the second groove 30, and are not in engagement with the first groove 26. The sipes in the tread 10, including the shoulder sipes and others, may have widths that are 2 millimeters or less. The sipes 34, 42 are straight in shape until they reach a position inboard of the first groove terminal end 28 in the lateral direction 14 and which time they are in a castle type shape until engagement with the second groove 30. The sipes 34, 42 have a rectangular cross-sectional shape, but can be wavy, curved, angled or variously shaped with various cross-sectional configurations in other exemplary embodiments. The geometry in the thickness direction 16 of the sipes 34, 42 can also vary so that the sipes 34, 42 have different cross-sectional shapes at different ones of their depth locations in the thickness direction 16. The sipes 34, 42 could have different depths along their lengths so as to be deeper or more shallow in the thickness direction 16 at various points. There can be sipes present anywhere in the tread 10, so long as there is a shoulder sipe 34 that engages the left side edge 20 and extends to and into engagement with the second groove 30, and does not engage the first groove 26.

[0028] The embodiment in Figs. 1 and 2 includes a third shoulder sipe 64, a fourth shoulder sipe 66, and a fifth shoulder sipe 68 that all engage the left side edge 20 and extend therefrom to the second groove 30 and in engagement therewith. These three shoulder sipes 64, 66, 68 do not engage the first groove 26. The third shoulder sipe 64 has a shape that is a castle type sipe. The fourth and fifth shoulder sipes 66, 68 have shapes that are straight lines. The shoulder sipes 34, 42, 64, 66, 68 are spaced from and not in engagement with one another, and have an angled direction such that they extend longer in the lateral direction 14 than they extend in the longitudinal direction 12.

[0029] The first groove 26 has a first groove terminal end 28 that is the portion of the first groove 26 that is at the end of the first groove 26 that is closest to the left side edge 20 in the lateral direction 14. The first groove terminal end 28 can be distinguished from the sides of the first groove 26 that are those that extend along the length of the first groove 26and are opposite to one another and define the width of the first groove 26. The tread 10 includes a blocking sipe 36 that engages the first groove terminal end 28 and extends therefrom. The blocking sipe 36, as with the other sipes in the tread 10, is an opening that extends into the tread 10 in the thickness direction 16 having a width that is 2 millimeters or less. The cross-sectional shape of the blocking sipe 36 can be rectangular or may be of any shape and can be the same shape and width along its entire height in the thickness direction 16 or may be of various shape and widths along its height.

[0030] The blocking sipe 36 extends for a longer distance in the longitudinal direction 12 than it extends in the lateral direction 14 from the first groove terminal end 28. In the Figs. 1 and 2 embodiment, the blocking sipe 36 extends only in the longitudinal direction 12 and has no component of extension in the lateral direction 14. In effect, the blocking sipe 36 extends in a straight line completely oriented in the longitudinal direction 12. The blocking sipe 36 extends for a length in the longitudinal direction 12 so that it engages the shoulder sipe 34, the second shoulder sipe 42 and the third shoulder sipe 64. The blocking sipe 36 terminates at the third shoulder sipe 64 and does not extend past the third shoulder sipe 64. The blocking sipe 36 does not engage the fourth shoulder sipe 66 or the fifth shoulder sipe 68.

[0031] The shoulder of the tread 10 is not bound by a circumferential groove that extends in the longitudinal direction 12 completely around the tire 5. Abnormal wear may develop and extend from the left side edge 20 inboard in the lateral direction 14 across the upper surface 18. The presence of the blocking sipe 36 functions to stop the development of abnormal wear inboard in the lateral direction 14 from the blocking sipe 36 so that the abnormal wear is found outboard from the blocking sipe 36 to the left side edge 20 in the lateral direction 14, but not inboard from the blocking sipe 36 in the lateral direction 14. The blocking sipe 36 does not extend to engagement with the second groove 30, and does not engage the fourth and fifth shoulder sipes 66, 68 because doing so would cause the formation of small blocks in the tread defined by these sipes 36, 66, 68 with the second groove 30. These small blocks might be susceptible to being torn off of the tread 10 so the blocking sipe 36 does not extend to the second groove 30 and terminates at a portion spaced some amount from the second groove 30. The tread 10 includes sipes that are within the rib 32 that engage both of the first and second grooves 26, 30 and do not engage the left or right side edges 20, 22.

[0032] Fig. 3 is an exemplary embodiment of the tread 10 that is similar to that as previously described and a repeat of this information is not needed. The tread 10 differs in that only three of the shoulder sipes 34, 42 and 64 are present and extend from the left side edge 20 to engagement with the second groove 30 and do not engage the first groove 26. The blocking sipe 36 extends in the longitudinal direction 12 and not the lateral direction 14 and engages and terminates at the first shoulder sipe 34. The blocking sipe 36 does not engage either the second shoulder sipe 42 or the third shoulder sipe 64 and does not extend beyond the first shoulder sipe 34 in the longitudinal direction 12. The first shoulder sipe 34 is a straight sipe that is angled twice and at the junction between two of the straight segments of the first shoulder sipe 34 is a pin hole feature 44. The blocking sipe 36 engages the pin hole feature 44 of the first shoulder sipe 34. The second shoulder sipe 42 likewise has a pin hole feature at the apex between two straight segments of the second shoulder sipe 42 that are oriented at different angles. The third shoulder sipe 64 has a castle type shape and does not have a pin hole feature. The aforementioned features of the tread 10 repeat completely around the entire circumference of the tire 5.

[0033] The pin hole feature 44 has a circular cross-sectional shape and has a depth that extends into the thickness direction 16 that is the same depth as that of the two straight extending portions of the first shoulder sipe 34. As such, the pin hole feature 44 and the two straight sipe sections have the same height as one another in the thickness direction 16. The two straight sipe sections open into the pin hole feature 44 and are in communication therewith. There can be multiple pin hole features 44 in the various shoulder sipes 34, 42 and 64, and there can be other types of features in the various shoulder sipes 34, 42, 64 in addition to or instead of the pin hole features 44. The pin hole feature 44 may be present to reinforce the linear portions of the shoulder sipe.

[0034] The various shoulder sipes 34, 42, 64, 66, 68 are described as terminating at grooves 26, 30. However, in some arrangements the shoulder sipes 34, 42, 64, 66, 68 could extend all the way from the left side edge 20 to the right side edge 22, although at least one of these shoulder sipes 34, 42, 64, 66, 68 should engage the second groove 30 so that the blocking sipe 36 could likewise engage it.

[0035] The embodiment in Fig. 4 has three shoulder sipes 34, 42, 64 in which the first and second shoulder sipes 34, 42 have two straight angled sections, and in which the third shoulder sipe 64 has a single straight section. There are no pin hole features 44 or other features in the three shoulder sipes 34, 42, 64 besides the straight sections. The blockingsipe 36 engages the first shoulder sipe 34 and terminates at the first shoulder sipe 34 and does not extend beyond the first shoulder sipe 34 in the longitudinal direction 12. The blocking sipe 36 engages the first shoulder sipe 34 at a location that is not at the meeting point between the two straight sections of the first shoulder sipe 34, but is at the straight section that engages the left side edge 20. The blocking sipe 36 extends less than half of the distance from the first groove terminal end 28 to the second groove 30 in the longitudinal direction 12. A plurality of micro sipes 46, in this case five micro sipes 46, engage the blocking sipe 36 and extend therefrom outboard in the lateral direction 14 towards the left side edge 20.

[0036] The micro sipes 46 are linear in shape extending from the blocking sipe 36 and terminate blindly within the tread 10 with terminal ends that are rectangular in shape, although they could be round or circular in other arrangements. All of the micro sipes 46 could be arranged in the same manner in that they all have the same shape and size and are all angled in the same direction relative to the lateral direction 14. As shown, the micro sipes 46 are oriented completely in the lateral direction 14 with no components of extension in the longitudinal direction 12, and the micro sipes 46 do not engage the left side edge 20. The micro sipes 46 are not full width sipes that extend across the entire shoulder section. The micro sipes 46 are spaced evenly from one another along the longitudinal length of the blocking sipe 36. The other blocking sipes 36 in the tread 10 are arranged in a manner similar to the one just described and a repeat of this information is not necessary. The micro sipes 46 generate coupling forces to reduce or eliminate irregular wear, and function to soften the tread 10 that is located at the blocking sipe 36. The tread 10 has micro sipes 46 that extend outboard from the various blocking sipes 36 in the lateral direction 14 so that they extend towards the side edge 20, 22 that is closer to them. There are no blocking sipes 36 present in the tread 10 that include micro sipes 46 that extend inboard from the blocking sipes 36 in the lateral direction 14. In fact, there are no micro sipes 46 present in the tread 10 other than those that engage the blocking sipes 36.

[0037] Fig. 5 is an alternate embodiment of the tread 10 in which again the tread pattern repeats itself around the entire circumferential length of the tire 5 in the longitudinal direction 12, and in which just a portion of this tread 10 is illustrated. The first shoulder sipe 34 has a pin hole feature 44 at which point the blocking sipe 36 terminates and does not extend beyond. The second shoulder sipe 42 has a pin hole feature 44 and three straight sections but the blocking sipe 36 does not engage the second shoulder sipe 42. A thirdshoulder sipe 64 is present and has a castle type shape and engages both the second groove 30 and the left side edge 20 and the blocking sipe 36 does not extend to the third shoulder sipe 64. The blocking sipe 36 has four micro sipes 46 that can be configured as previously discussed. However, unlike the prior embodiment the micro sipes 46 that extend from the blocking sipe 36 extend inboard in the lateral direction 14 and none of them extend from the blocking sipe 36 outboard in the lateral direction 14 towards the left side edge 20. In fact, all of the micro sipes 46 in the entire tread 10 that engage the various blocking sipes 36 extend inboard in the lateral direction 14 towards the lateral midpoint of the tread 10, and none of them extend outboard in the lateral direction 14 towards the closest side edge 20, 22. The presence of the micro sipes 46 with the blocking sipe 36 function to soften the tread 10 in this area and reduce the propagation of irregular wear.

[0038] Figs. 6 and 7 show an alternate exemplary embodiment of the tread 10 in which there are again three shoulder sipes 34, 42, 64 present and in which the blocking sipe 36 engages and terminates at the first shoulder sipe 34 but does not engage the second or third shoulder sipes 42, 64. The blocking sipe 36 is oriented completely in the longitudinal direction 12 with no component of extension in the lateral direction 14 and extends from the first groove terminal end 28 to the pin hole feature of the first shoulder sipe 34. However, the blocking sipe 36 is angled relative to the thickness direction 16 such that it extends towards the left side edge 20 as it extends in the thickness direction 16 from the upper surface 18. All of the blocking sipes 36 in this embodiment are configured the same in that they all extend outboard in the lateral direction 14 towards their closest side edge 20, 22 upon extension towards the central axis 60 in the thickness direction 16.

[0039] In the Fig. 7 cross-sectional view taken in the lateral direction 14 through the blocking sipe 36 along a portion of the tread 10. The body of the blocking sipe 36 is oriented relative to the thickness direction 16 so that it has components of extension that are not only in the thickness direction 16, but in both the lateral direction 14 and the thickness direction 16. A blocking sipe top point 52 is present at the top of the blocking sipe 48 at the outer surface 18. The blocking sipe 36 extends into the tread 10 until it terminates at a blocking sipe bottom 48 which is the location farthest from the opening at the blocking sipe top point 52. A blocking sipe bottom point 50 is noted at a location at the blocking sipe bottom 48. A sipe inclination line 54 extends from the blocking sipe bottom point 50 to the blocking sipe top point 52. The blocking sipe bottom 48 of the blocking sipe 36 has a flat, linear cross-sectional shape, but this feature is optional in otherembodiments as the blocking sipe bottom 48 could have a triangular shape or a teardrop could be located at the blocking sipe bottom 48. The sipe inclination line 54 is a straight line through points 50 and 52 and would still be a straight line even if the body of the blocking sipe 36 were wavy, curved, angled, or irregular in shape.

[0040] A reference line 56 extends through the blocking sipe bottom point 50 and through the outer surface 18. The reference line 56 is oriented completely in the thickness / radial direction 16 and does not have a component in the longitudinal / circumferential direction 12 or the lateral / axial direction 14. The inclination of the blocking sipe 36 is observed upon comparison of the orientation of the inclination line 54 to the reference line 56. The inclination line 54 is oriented at a blocking sipe inclination angle 70 to the reference line 56. The blocking sipe inclination angle 70 may be from 10 degrees to 45 degrees, from 11 degrees to 45 degrees, from 10 degrees to 20 degrees, from 11 degrees to 20 degrees, from 10 degrees to 15 degrees, from 5 degrees to 15 degrees, from 13 degrees to 23 degrees, from 15 degrees to 28 degrees, from 15 degrees to 30 degrees, from 18 degrees to 28 degrees, from 20 degrees to 25 degrees, from 20 degrees to 45 degrees, or from 12 degrees to 23 degrees in accordance with various exemplary embodiments. The blocking sipe inclination angle 70 values that were given represent a magnitude of the angle 70, and these magnitudes can be for blocking sipe inclination angles 70 oriented in any direction. The use of a blocking sipe inclination angle 70 that is greater than 0 degrees may help to provide irregular wear protection to the tread 10. The distance between the blocking sipe bottom point 50 and the blocking sipe top point 52 in the lateral direction 14 may be from 4-6 millimeters in accordance with certain exemplary embodiments.

[0041] Another embodiment of the tread 10 is shown in Fig. 8 in which three shoulder sipes 34, 42, and 64 are present that engage the second groove 30 but not the first groove 26. The blocking sipe 36 engages only the first shoulder sipe 34 and not the second or third shoulder sipes 42, 64. The tread 10 is arranged so that there are no castle shaped shoulder sipes, but castle shaped sipes are present in the rib 32 and other ribs of the tread 10. The blocking sipe 36 is angled so as to extend in the lateral direction 14 upon extension downward in the thickness direction 16 from the upper surface 18 the same way as was previously discussed with respect to the Figs. 6 and 7 embodiment, however the direction of extension is opposite. In this regard, the blocking sipe 36 extends inboard in the lateral direction 14 upon extension downward in the thickness direction 16 away from the uppersurface 18. All of the blocking sipes 36 in the tread 10 can be arranged in a similar manner in that they all extend inboard in the lateral direction 14 towards the lateral midpoint of the tread 10 upon extension downward in the thickness direction 16. None of the blocking sipes 36, or any other sipe in the tread 10, extend outboard in the lateral direction 14 upon downward extension in the thickness direction 16.

[0042] Fig. 9 shows another embodiment of the tread 10 in which the grooves 26, 30 are similar to previous embodiments, and in which there is no shoulder groove. Three shoulder sipes 34, 42, 64 extend from the left side edge 20 to engagement with the second groove 30, and these sipes 34, 42, 64 are out of engagement with the first groove 26. Each one of the shoulder sipes 34, 42, 64 includes a pin hole features 44. None of the shoulder sipes 34, 42, 64 are castle type sipes, although other sipes in the tread 10 have a castle type configuration, such as sipes present within the rib 32. The shoulder sipes 34, 42, 64 all have straight sections with the pin hole feature 44 of the first shoulder sipe 34 being the only one that is present at a meeting point between two straight sections that are oriented at different angles to the lateral direction 14. The blocking sipe 36 engages the first shoulder sipe 34 and terminates at the first shoulder sipe 34 without engaging the second or third shoulder sipe 42, 64. The blocking sipe 36 extends from the first groove terminal end 28 in the longitudinal direction 12 without a component of extension in the lateral direction 14. The blocking sipe 34 extends less than half of the distance to the second groove 30 in the longitudinal direction 12 measured in relation to a common position in the lateral direction 14 from the first groove terminal end 28 to the second groove 30.

[0043] Fig. 10 is a cross-sectional view of the blocking sipe 36 of Fig. 9, and the blocking sipe 36 extends in the thickness direction 16 without a component of extension in the lateral direction 14. The blocking sipe 36 is oriented so that the inclination line 54 and the reference line 56 are on top of one another and the blocking sipe inclination angle 70 is zero degrees. The body of the blocking sipe 36 is rectangular, but the blocking sipe bottom 48 is not. Instead, a teardrop 58 is present at the blocking sipe bottom 48 such that the blocking sipe 36 is wider in the lateral direction 14 at the blocking sipe bottom 48 than at its body which is closer to the upper surface 18 in the thickness direction 16. The teardrop 58 is circular in shape with the exception of the opening into the body of the blocking sipe 36, and the teardrop 58 helps prevent the formation of cracks at the blocking sipe bottom 48.

[0044] Fig. 11 shows another embodiment in which the tread 10 is arranged in the same manner as the Fig. 10 embodiment with the exception of the configuration of the blocking sipe 36. Here, the blocking sipe 36 extends from the first groove terminal end 28 so as to have a component of extension in both the longitudinal direction 12 and the lateral direction 14. The blocking sipe 36 is has a straight segment that extends from the first groove terminal end 28 outboard in the lateral direction 18 towards the left side edge 20 and rearward in the longitudinal direction 12 in the opposite direction from the rolling direction 62. The blocking sipe 36 engages the pin hole feature 44 of the first shoulder sipe 34. At this point, the blocking sipe 36 extends in the longitudinal direction 12 to engagement with the second shoulder sipe 42 without a component of extension in the lateral direction 14. The blocking sipe 36 terminates at the second shoulder sipe 42 and does not engage or extend to the third shoulder sipe 64 and does not go beyond the second shoulder sipe 42 in the longitudinal direction 12. The blocking sipe 36 thus changes direction one time in its extension from the first groove terminal end 28, but in other embodiments it may change direction two, three, or more times. Although the blocking sipe 36 has been shown as a straight sipe, it could be wavy, curved, or shaped differently other than straight in other arrangements.

[0045] The blocking sipe 36 can extend into the tread 10 in the thickness direction 16 so as to have a depth that is the same as the depth of the first groove 26. In other embodiments, the first groove 26 extends a greater depth into the tread 10 in the thickness direction 16 than does the blocking sipe 36 extend into the thickness direction 16. The tread 10 can be arranged so that no other sipes engage the first groove terminal end 28 except for the blocking sipe 36. The blocking sipe 36 functions to reduce the propagation of irregular wear in that irregular wear may start at the left side edge 20 and propagate inboard in the lateral direction 14 until reaching the blocking sipe 36 at which point it stops and does not move past the blocking sipe 36 so as to move inboard of the blocking sipe 36 in the lateral direction 14. With respect to blocking sipes 36 on the right shoulder, these blocking sipes 36 stop the propagation of irregular wear from the right side edge 22 that moves inboard in the lateral direction 14. The irregular wear will stop at the blocking sipe 36 and move inboard of the blocking sipe 36 in the lateral direction 14.

[0046] Although the design has been described with mostly reference to two grooves, the first groove 26 and the second groove 30, it is to be understood that this is simply for sake of convenience as multiple grooves greater than two in number can be arranged in themanners as described with respect to the two grooves 26, 30. As such, the tread 10 can include any number of grooves. Likewise, any number of ribs 32 can be present and any number of sipes in the shoulders or in from the shoulders can be present. The tread 10 has likewise been described with respect to one blocking sipe 36 that interacts with the first groove 26 and one or more of the shoulder sipes 34, 42, 64, 66, 68. However, multiple blocking sipes can be present in the tread 10 and can be arranged in manners similar to those discussed with reference to the blocking sipe 36 near the left side edge 20. The various embodiments include elements that can be combined with elements from other embodiments. The first groove 26 and the second groove 30 are successive in that they are arranged on the tread 10 so that no other groove is between them. If there is another groove at some point between the first and second grooves 26, 30, such groove would not be located at the same position in the lateral direction 14 as the first groove terminal end 28.

[0047] The blocking sipes 36 do not extend circumferentially completely around the entire tire 5 in the longitudinal direction 12, but rather extend only a distance into the longitudinal direction 12 before terminating at a shoulder sipe. Although the embodiments have been shown as having one or more shoulder sipes, such as the second shoulder sipe 34 and the third shoulder sipe 64, in the shoulder rib but not engaged by the blocking sipe 36 it is to be understood that this need not be the case in other arrangements. In this regard, the blocking sipe 36 may engage all of the shoulder sipes within the shoulder rib so long at it stops short of engagement with the second groove 30. However, if there are shoulder sipes that engage the second groove 30 and are close to the terminal end of the second groove 30 that is closest to the left hand side 20, geometries such as small blocks should be avoided so that they do not tear from the tread 10 during use. As such, one may not want to engage all of the shoulder sipes with the blocking sipe 36 in these instances, but it is within the scope of the present embodiment that all of them are engaged in some arrangements.

[0048] Blocking sipes 36 that extend more in the longitudinal direction 12 than in the lateral direction 14 function to stop the propagation of irregular wear past them to locations inboard of the blocking sipe 36 that would otherwise occur until it reaches the second groove 30. Inhibiting or delaying the formation of irregular wear may improve customer satisfaction and potentially increase the mileage of the tread 10 before the tire 5 is removed from service. The tire 5 may be a drive tire of a tractor trailer. However, the tire 5 may also be a steer tire or trailer tire of a tractor trailer in other embodiments.

[0049] 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 present disclosure 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 longitudinal direction, a lateral direction, and a thickness direction; an upper surface; a left side edge; a right side edge, wherein a rolling tread width extends from the left side edge to the right side edge in the lateral direction; a first groove that is not completely oriented in the longitudinal direction so as to extend in both the longitudinal direction and the lateral direction, wherein the first groove is spaced from and free from engagement with both the left side edge and the right side edge, wherein the first groove has a first groove terminal end; a second groove that is not completely oriented in the longitudinal direction so as to extend in both the longitudinal direction and the lateral direction, wherein the second groove is spaced from and free from engagement with both the left side edge and the right side edge; a rib located between and in engagement with the first groove and the second groove, wherein the rib is not completely oriented in the longitudinal direction so as to extend in both the longitudinal direction and the lateral direction; a shoulder sipe that engages the left side edge and extends from the left side edge to the second groove and engages the second groove, wherein the shoulder sipe is free from engagement with the first groove; and a blocking sipe that engages the first groove terminal end and extends from the first groove terminal end to and in engagement with the shoulder sipe, wherein the blocking sipe is free from engagement with the second groove, and wherein the blocking sipe extends a greater distance in the longitudinal direction than in the lateral direction.

2. The tread as set forth in claim 1, wherein the first groove is free from engagement with the second groove.

3. The tread as set forth in claims 1 or 2, wherein both the first groove and the second groove extend at a constant single angle to the longitudinal direction.

4. The tread as set forth in any one of claims 1-3, wherein the blocking sipe terminates at the shoulder sipe and engages only the shoulder sipe and the first groove terminal end.

5. The tread as set forth in any one of claims 1-3, wherein the shoulder sipe is a first shoulder sipe, and further comprising a second shoulder sipe that engages the left side edge and extends from the left side edge to the second groove and engages the second groove, wherein the second shoulder sipe is free from engagement with the first groove, and wherein the blocking sipe extends from the first shoulder sipe to and in engagement with the second shoulder sipe.

6. The tread as set forth in any one of claims 1-5, wherein the shoulder sipe has a pin hole feature, and wherein the blocking sipe engages the pin hole feature of the shoulder sipe.

7. The tread as set forth in any one of claims 1-6, wherein the blocking sipe extends only in the longitudinal direction and does not extend in the lateral direction.

8. The tread as set forth in any one of claims 1-7, further comprising a plurality of micro-sipes that engage the blocking sipe, wherein the micro-sipes are blind and are free from engagement with the left side edge, the first groove, the second groove, and the shoulder sipe.

9. The tread as set forth in claim 8, wherein the micro-sipes extend from the blocking sipe towards the left side edge, and wherein there are no micro-sipes that engage the blocking sipe and extend from the blocking sipe towards the right side edge.

10. The tread as set forth in claim 8, wherein the micro-sipes extend from the blocking sipe towards the right side edge, and wherein there are no micro-sipes that engage the blocking sipe and extend from the blocking sipe towards the left side edge.

11. The tread as set forth in any one of claim 1-10, wherein the blocking sipe has a blocking sipe bottom, wherein a blocking sipe bottom point is located at the blocking sipebottom, wherein a blocking sipe top point is located at the blocking sipe at the upper surface having the same position as the blocking sipe bottom point in the longitudinal direction, wherein an inclination line extends from the blocking sipe bottom point to the blocking sipe top point, wherein a reference line extends in the thickness direction through the blocking sipe bottom point, and wherein the reference line does not have a component in the longitudinal direction or the lateral direction, wherein the inclination line is at a blocking sipe inclination angle to the reference line that is not zero degrees.

12. The tread as set forth in claim 11, wherein the blocking sipe bottom point is located closer to the left side edge in the lateral direction than the blocking sipe top point is to the left side edge in the lateral direction.

13. The tread as set forth in claim 11, wherein the blocking sipe top point is closed closer to the left side edge in the lateral direction than the blocking sipe bottom point is to the left side edge in the lateral direction.

Images