Wavy sipe molding element for improved tire performance and economical mold manufacturing

Abstract

A tire mold and a method of manufacturing the tire mold having a plurality of sipes, each sipe disposed between opposing surfaces of the tread within the tread thickness, each sipe having a thicker frame portion (40) contacting and extending beyond the ground-engaging surface of the tire tread therein, and a thinner portion (42) forming a plurality of projections (36) on at least one of opposing sides of the sipe thickness, the plurality of projections being spaced apart, each projection having a height equal to or less than the thickness of the frame portion of the sipe.

Description

[Technical Field]

[0001] This invention relates to tire treads, and more particularly to the placement and formation of sipes within tire treads, molds used to manufacture tire treads, and methods for making such molds having complex sipe-molding member shapes. [Background technology]

[0002] Sipes are commonly used in tire treads. Sipes form very narrow grooves or slits within the thickness of the tire tread that are configured to close or remain closed at certain times within a footprint during tire operation. The footprint refers to the contact area between the tire and the ground. In certain instances, to create an interlocking effect between opposing tread surfaces between which the sipe is disposed (i.e., between opposing sides of the tread that form the sipe), the opposing sides or surfaces are corrugated both along the depth and length of the sipe. This interlocking can improve treadwear but can worsen rolling resistance. More sophisticated corrugated sheets, such as those found in U.S. Pat. No. 11,338,618, that address these issues result in weak mold parts that add cost and expense to tire manufacturing, making further use of this technology cost-prohibitive, especially in multi-segment tire molds such as tire puzzle molds. Such complex tire sipe shapes have traditionally required a flexible or fragile mold negative (used herein to describe a positive blank used to cast a mold and having the shape of the final product) to allow the complex shape of the sipe molding member to be released from the mold negative when embedded in the mold, which adds cost. Therefore, there is a need to improve tread wear and reduce rolling resistance while reducing manufacturing costs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 11,338,618 Summary of the Invention [Means for solving the problem]

[0004] Certain embodiments of the present invention include a tire tread having a plurality of sipes, wherein at least one of the opposing sides of the sipe thickness includes a plurality of projections, and a method of forming the same.

[0005] A particular embodiment of a tire tread having a plurality of sipes includes a tire tread having a length extending in a longitudinal direction, which is the circumferential direction when the tread is disposed on the tire, a width extending laterally perpendicular to the length direction, and a thickness extending in a depth direction from an outer ground-engaging side of the tread, the depth direction being perpendicular to both the length and width directions of the tread. Each of the plurality of sipes has a length extending at least partially in the tread length or width direction, a height extending at least partially in the tread depth direction and perpendicular to the tread length, and a thickness. Each sipe is disposed between opposing surfaces of the tread within the tread thickness. Each sipe has a thicker frame portion (or "thick portion") and a thinner portion forming a plurality of spaced-apart projections on at least one opposing side of the sipe thickness. In a particular example, each projection has a height equal to or less than the thickness of the sipe frame portion.

[0006] In certain embodiments, a method for forming a tire tread having a plurality of sipes includes molding each of a plurality of sipes using a sipe molding member. Each sipe molding member has a length configured within the tread to extend at least partially in the direction of the tread length or width, a height configured within the tread to extend at least partially in the direction of the tread depth and perpendicular to the tread length, and a thickness. Each sipe molding member is disposed between opposing surfaces of the tread within the tread thickness. At least one of the opposing sides of the sipe molding member thickness includes a plurality of spaced-apart projections. The method for forming a tire tread having a plurality of sipes further includes removing the sipe molding member, leaving the sipes in the tread. The sipes have voids formed as the sipe molding member and a plurality of projections corresponding to the plurality of projections disposed along the sipe molding member.

[0007] In other embodiments, a mold part and method of making the mold part for use in manufacturing tires having multiple sipes with complex shapes are disclosed.

[0008] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following specification and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0009] A full and enabling disclosure of this invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in this specification, and reference is made to the accompanying drawings, in which: [Brief explanation of the drawings]

[0010] [Figure 1] 1 provides a perspective view of a tire tread having an embodiment of an inventive sipe disclosed herein;

[0011] [Figure 2] 2 provides an enlarged perspective view of the tire shown in FIG. 1.

[0012] [Figure 3] 1 provides a perspective view of an embodiment of a sipe mold member having a thick frame-forming portion and a thin corrugated portion, the corrugations along the length of the sipe mold member;

[0013] [Figure 4] 4 provides a top view of the sipe molding member of FIG. 3.

[0014] [Figure 5] 5 provides a cross-sectional view of the sipe molding member taken along line 5-5 of FIG. 3.

[0015] [Figure 6] 6 provides a cross-sectional view of the sipe mold member taken along line 6-6 of FIG. 3.

[0016] [Figure 7] 1 provides a perspective view of an embodiment of a sipe mold member having a thick frame-forming portion and a thin corrugated portion, the sipe mold member having curved corrugations along the length of the sipe mold member.

[0017] [Figure 8] 8 provides a top view of the sipe molding member of FIG. 7.

[0018] [Figure 9] 9 provides a cross-sectional view of the sipe molding member taken along line 9-9 of FIG. 7.

[0019] [Figure 10] 10 provides a cross-sectional view of the sipe molding member taken along line 10-10 of FIG. 7.

[0020] [Figure 11] 1 provides a perspective view of an embodiment of a sipe molding member having a thick frame-forming portion and a thin corrugated portion.

[0021] [Figure 12] 12 provides a cross-sectional view of the sipe molding member taken along line 12-12 of FIG.

[0022] [Figure 13] 13 provides a cross-sectional view of the sipe molding member taken along line 13-14 of FIG. 11.

[0023] [Figure 14] 1 provides a perspective view of a mold part used to mold a tire and having an embodiment of a sipe mold member.

[0024] [Figure 15] 1 provides a perspective view of a mold negative for forming a mold part used to mold a tire and having an embodiment of a sipe mold member.

[0025] [Figure 16] 1 shows the insertion of a sipe molding member into a mold negative.

[0026] [Figure 17] 1 shows the casting of mold material used to form tire mold parts into the mold negative.

[0027] [Figure 18] 10 illustrates the separation of a mold part from a mold negative with sipe mold members embedded in the mold part. DETAILED DESCRIPTION OF THE INVENTION

[0028] The use of the same or similar reference symbols in different figures refers to the same or similar features.

[0029] The present invention includes tire treads, tires including such treads, methods for forming tire treads, molds, and methods for forming the molds, any such treads including sipes having the surface configurations described herein. To describe the invention, reference will now be made in detail to embodiments and / or methods of the invention. One or more examples of the invention are illustrated in or by the drawings. Each example is provided by way of explanation of the invention, and not as a limitation of the invention. Indeed, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features or steps illustrated or described as part of one embodiment can be used with other embodiments or steps to yield a further embodiment or method. Accordingly, it is intended that the present invention cover modifications and variations that come within the scope of the appended claims and their equivalents.

[0030] With respect to tire treads described herein, it is understood that each such tread includes a length, a width, and a thickness. The length extends in a longitudinal direction. The length direction of a tread is the circumferential (i.e., annular) direction when the tread is placed on the tire, as the tread may be formed with the tire or may be formed separately for later installation on the tire, such as during a retreading operation. The width extends in a lateral direction, the lateral direction being perpendicular to the length direction, and the thickness extends in a depth direction from the outer, ground-engaging side of the tread, the depth direction being perpendicular to both the length direction and the width direction of the tread.

[0031] The present invention introduces a sipe surface geometry that increases surface friction between the opposing sides of the tread where the sipe is located and improves the interlock between the opposing sides of the tread, while simultaneously improving the release of the tire tread from the mold and increasing the durability of the tire tread mold components involved in creating the sipe features, while allowing for the use of economical mold manufacturing methods. Wear improvements comparable to conventional corrugated sipes can then be achieved, while reducing mold wear and tear, downtime and scrapped tires, and the manufacturing costs of each tire mold and tire, without significantly reducing rolling resistance. Furthermore, because the new surface geometry further increases the durability of the sipe mold members, a wider sipe molding area along the mold members can be achieved and / or the thickness of the sipe molding area can be reduced, each of which can result in further improvements in wear without significantly reducing rolling resistance.

[0032] It is understood that the surface shapes described herein may be applied to any sipe known to those skilled in the art, or obvious variations thereof. For example, referring to the exemplary embodiment shown in FIG. 1 , a partial perspective view of a tire tread 10 is shown having a plurality of tread blocks 12, each including a sipe 14. One sipe 14 is shown in greater detail in a partial cutaway view of a particular tread block 12, and then in an enlarged view in FIG. 2 . As shown, the tread 10 includes a plurality of sipes 14, each sipe 14 having a length L14 extending at least partially in the direction of the tread length L10 or width W10, a height H14 extending at least partially in the direction of the tread depth T10 and perpendicular to the tread length, and a thickness T14. As best seen in FIG. 1 , each sipe 14 is disposed between opposing sides or surfaces 16 of the tread within the tread thickness.

[0033] It is understood that the sipe may form a planar or contoured sipe. In other words, the body of the sipe may be planar or contoured. Planar sipes are sometimes referred to as straight sipes. Contoured sipes are non-planar, with a thickness extending in the direction of the sipe length and / or height along any desired non-linear path, which may be, for example, a curved or wavy path. In an exemplary embodiment, as seen in FIGS. 1-2 , the sipe thickness T14 (forming the body of the sipe) varies from a thicker frame portion 15 to a corrugated, thin portion 17, which corrugates back and forth along a first path P1 in the direction of the tread length L10 as the sipe extends in the direction of the sipe height H14 (which in the illustrated embodiment is also in the direction of the tread depth T10). The thin portion may be 0.15 mm to 0.4 mm thick in at least one embodiment. In other variations, the first path is corrugated from front to back in the direction of the tread length L10, and the first path extends in the direction of the sipe length L14, which in the embodiment shown is in the direction of the tread width W10. Of course, the sipes 14 may be formed in any configuration within the tread, and therefore the sipe length and width may extend at least partially in any direction of the tread length or width. Because the corrugation thickness does not relate to or act as any surface shape, the corrugation thickness of the sipe is sometimes referred to as the corrugation body. As noted above, when a sipe is more generally of a planar or contoured shape, the body of the sipe can be said to be planar or contoured.

[0034] Because the first path forms multiple corrugations, the first path can be described as a nonlinear corrugation path. In the illustrated embodiment, the corrugation path comprises a series of line segments to form a stepped or zigzag corrugation path, but in other variations, the corrugation path may be curved. A sipe frame portion 15 extending along the length of the sipe and having a thickness measured in the thickness direction is formed by a thickened portion of the sipe surrounding a thinner portion 17 of the sipe corrugation. The amplitude of the corrugation in the height direction H14 of the corrugation portion is less than or equal to the thickness of the frame portion surrounding the corrugation. The amplitude of the corrugation is measured from the peak of the protrusion in the thickness direction on a first side of the sipe to the adjacent side at the base of the corrugation.

[0035] It is understood that the surface profiles described herein may apply to any sipe known to those skilled in the art, or any obvious variations thereof, particularly to the variations of sipes described herein. A sipe (and its thickness or body) may not be corrugated at all in a particular direction or at a particular location on the sipe, or may be corrugated in one or more directions. For example, a sipe (and its thickness or body) may not only be corrugated back and forth as the sipe extends in a particular direction, but also be corrugated back and forth as the sipe extends in another direction. When extending in a second direction, the sipe (and its thickness or body) can be said to be corrugated in a second direction along a second path (a second nonlinear corrugation path). For example, referring to FIG. 3 , the sipe molding member 30 forming the sipe 14 is shown to be corrugated as the sipe extends both along the sipe molding member height H30 (through the nonlinear corrugation path P1) and along the sipe molding member length L30 (through the second stepped corrugation path including the linear segment P2). The thin sipe molding portion 42 has a series of corrugations 32 in the height direction H30. In this embodiment, the two directions are perpendicular to one another. Furthermore, in other embodiments, the two directions may be biased toward one another at an angle other than 90 degrees (perpendicular). With reference to FIG. 3 , it should be noted that the thick sipe molding portion 40 and the thin sipe molding portion 42, which serve to form the sipe frame portion 15, both have corrugations along paths extending in the length direction L30 of the sipe molding portion of the sipe molding member. It should also be noted that the amplitude of the corrugations of both the thick sipe molding portion 40 and the thin sipe molding portion 42 along paths extending in the length direction L30 may be greater than the thickness of the thick sipe molding portion 40, as shown in FIG. 4 , which shows a height elevation view of the sipe 30. This is permissible, provided that the corrugations extending along a height path do not have an amplitude greater than the thickness of the thick sipe molding portion 40.

[0036] A cross-section of the embodiment taken along line 5-5 in FIG. 4 is shown in FIG. 5. Three protrusions 36 are shown in cross-section with an amplitude measured in the thickness direction T30 of the sipe molding member 30 no greater than the amplitude of the thickness of the thick sipe molding portion 40 measured in the thickness direction T30 of the sipe molding member. A recess 38 is positioned opposite each protrusion 36. The thin sipe molding portion 42 terminates in a teardrop-shaped void-forming portion 44 in the sipe molding portion height direction H30. FIG. 6 shows a cross-section of the embodiment taken along line 6-6 in FIG. 4. As can be seen here, some portions of the thin sipe molding portion 42 may be free of corrugations. This particular vertical portion is between the circular protrusions 36 within the thin sipe molding portion 42 of the sipe molding member 30.

[0037] FIG. 7 illustrates another embodiment having nonlinear corrugations along the length L30 of the sipe molding member 30 of the mold. This longitudinally oriented curved corrugation 46 along the length of the sipe molding member does not have linear portions except at the end regions, which are longitudinally oriented linear portions 48 shown in FIG. 8. The thin sipe molding member 42 has reinforcements 50 formed by thickened portions of the thin sipe molding member. The reinforcements 50 may be the same thickness as the thick sipe molding member 40, or, as shown in this embodiment, may be thinner than the thick sipe molding member 40 but thicker than the thin sipe molding member 42. These particular reinforcements 50 are located in positions where there are no protrusions 36 and are oriented in the height direction H30 of the sipe molding member 30. As with the previous embodiment, this sipe molding member 30 embodiment does not have corrugations in the sipe height direction H30 with a greater amplitude than the thick sipe molding member 40.

[0038] 9 and 10 are cross-sectional views taken along lines 9-9 and 10-10, respectively, showing a cross section of the sipe molding member in the height direction H30. The amplitude A of the waveform along the path extending in the height direction formed by the protrusions 36 of the sipe molding member is smaller than the thickness of the thin sipe molding portion 40 measured in the thickness direction T30 of the sipe molding member.

[0039] FIG. 11 illustrates yet another embodiment having a thick sipe molding portion 40 with a height, measured in the sipe height direction H30, that varies along the sipe length direction L30. The sipe molding member 30 of this embodiment is linear along the length of the sipe, except for the corrugations formed by the projections 36 in the thin sipe molding portion 42. In this embodiment, the projections 36 are positioned at various heights in the sipe height direction H30, as indicated by the slightly lower positioning of the central three projections 36. Reinforcements 50 provide additional durability to the thin sipe molding portion of the sipe molding member 30. FIGS. 12 and 13 illustrate cross sections along lines 12-12 and 13-13, respectively, of FIG. 11, illustrating that, like the other embodiments, the amplitude of the corrugations in the height direction H30 of the sipe molding member 30 is equal to or less than the thickness of the thick sipe molding portion 40 of the sipe molding member. Figure 11 shows the protrusions 36 arranged in rows, forming a left pair of rows of four protrusions per row, a middle row of three protrusions, and a right pair of rows of four protrusions per row. Figure 12 shows the protrusions in the middle row offset from the protrusions in the left and right rows such that the rows adjacent to the middle row are shifted so that each protrusion in the adjacent row is positioned adjacent to the recess 37 in the adjacent row. In this manner, the protrusions are not at the same height, and adjacent rows are offset. In this particular embodiment, adjacent rows of protrusions are offset in the height direction of the sipe molding member by half the distance between adjacent protrusions.

[0040] The sipe molding element 30 disclosed herein is useful for tire molds, particularly those consisting of multiple mold pieces that form the tread. Such molds, known in the industry as "puzzle molds," are characterized by numerous minute gaps formed by parting lines between single segments that allow gases to escape the mold during the tire-building process. A single-piece tire puzzle mold 60 is shown in FIG. 14. The gaps are intended to have tight tolerances to allow gases to escape without releasing the rubber mix during molding. The exterior of the mold requires few or no exhaust vents, such as small holes drilled into the mold, which tend to form elongated, hair-like vent spews. Eliminating spews results in a smoother final product and reduces the need to remove excess rubber after molding, which can affect the tire's aesthetics.

[0041] When creating a "puzzle mold," one method of creating the mold 60 is to create a mold negative 80 as shown in FIG. 15. The mold negative 80 has slots 82 for receiving and temporarily holding the sipe mold members 30 in the correct position relative to the other surface features of the mold. During the process of manufacturing the tire mold 60, the mold negative 80 is created and the sipe mold members 30 that will become part of the mold 60 are inserted into the sipe mold member retention slots 82, as shown in FIG.

[0042] The mold material 58, typically metal, used to make the mold 60 is poured or cast into the mold negative 80 and allowed to harden, as shown in FIG. 17. The gap between the slot 82 and the sipe mold member 30 is small enough to prevent the mold material 58 from filling in the corrugations of the thin sipe mold portion 42 of the sipe mold member 30. The portion of the sipe mold member 30 extending outside the slot 82 in the mold negative 80 is captured by the mold material 58 so that when the mold 60 is removed from the mold negative 80, the sipe mold member 30 is held in place within the mold 60, as shown in FIG.

[0043] A plurality of these individual molds 60 are circumferentially arranged as part of a tire mold to form the surface of the tire's tread.

[0044] The amplitude H14 of the waveform of the sipe molding member 30 in the height direction of the sipe must have an amplitude T14 measured in the thickness direction of the sipe that is less than or equal to the thickness of the thick sipe molding portion to allow the sipe to be released from the mold negative 80 and the mold 60 to be separated from the mold negative 80.

[0045] With respect to the surface profile for application to any desired sipe, and thus to one or both of the opposing tread sides or surfaces between which the sipe is disposed and defined, the resulting profile provides surface features including a plurality of protrusions and / or recesses that form a non-planar or contoured surface, much like a textured surface, such that the opposing sides of the tread between which the sipe is disposed experience increased friction when relative movement between the two sides is attempted during tire operation. When applying the surface profile to a sipe, the surface profile is also applied to a plurality of corrugations, i.e., the sipe body. It is understood that the spaced apart protrusions form interstitial spaces disposed between the protrusions, and the interstitial spaces are recesses relative to the protrusions. Of course, the reverse is also true: the spaced apart recesses form interstitial spaces between the recesses, and the interstitial spaces protrude relative to the recesses. Thus, the terms protrusions and recesses are used in relation to each other, not how they are formed along the surface. Furthermore, it should be noted that the protrusions of a sipe are associated with corresponding recesses on one of the opposing sides or surfaces, and vice versa. In certain embodiments, the surface features are formed such that the surface features located on opposing sides generally interlock, such as when the opposing sides are mirror images of one another.

[0046] 1 and 2, surface features including a plurality of projections 18 and corresponding recesses 20 are shown along one of the opposing sides or surfaces 16 of the tread 10, with a sipe disposed therebetween and defining the sipe. The plurality of projections 18 and recesses 20 are spaced apart along the length L14 and height H14 of the sipe. In the illustrated variation, the projections and recesses are uniformly spaced, but it should be understood that in other variations, the projections and / or recesses may be uniformly or non-uniformly spaced, as desired. While the arrangement of the projections 18 and recesses 20 is shown to form a generally smooth or rounded contoured surface, it is contemplated that more defined projections and / or recesses may be provided such that the surface is not smoothly contoured, such as when the projections form a cylinder, rectangle, or pointed cone. In certain embodiments, the smooth or rounded contoured surface shown in FIG. 3 comprises a plurality of uniformly spaced projections 36 and recesses 38, representing a hemispherical shape.

[0047] The smooth or rounded profile is further described as extending along a corrugation path in two perpendicular directions at a particular location. In certain embodiments, particularly with reference to FIGS. 3, 4, 5, and 6, the plurality of projections 36 of the sipe molding member are spaced apart from the center of one projection to the center of an adjacent projection, or from peak to peak, and have a height (also referred to as amplitude). The height or amplitude is measured from the base or bottom of the projection. The projections and recesses are arranged along a corrugation path to form a plurality of corrugations having a period (the spacing from the center of one projection to the center of an adjacent projection, or from peak to peak) of 0.8 to 2.0 mm, 1.5 to 2.0 mm, or 1.6 to 1.8 mm, and an amplitude generally in the range of 0.3 to 0.9 mm or 0.5 to 0.7 mm in other variations, less than that of a thicker sipe molding portion, or as shown in the embodiment of FIG. 11, having a frame thickness of 0.6 mm. In such embodiments, the corrugations are in the thin section with a thickness ranging from 0.15 mm to 0.4 mm from the first side of the thin section to the second side of the thin section. In such embodiments, the amplitude measures the distance between the base and peak along the corrugation within a single period. It is understood that the corrugations may be formed along the surface without affecting the other side of the sipe, or the sipe thickness may corrugate along the corrugation path, resulting in a protrusion formed on one side of the sipe and a recess formed opposite the protrusion on the other side of the sipe. In at least one embodiment, the corrugations have a period of 1.0 mm to 2.4 mm.

[0048] It is understood that any sipe described herein can be formed by any known method for forming sipes in a tread. For example, a method for forming a tire tread includes molding each of a plurality of sipes using a sipe molding member. The sipe molding member includes a portion having the same shape as any particular sipe described herein, with such portion of the sipe molding member being a solid form of the sipe that is a void. Each sipe molding member is disposed within the tread thickness between opposing surfaces or sides of the tread within the tread thickness. The sipe molding member thickness T30 corrugates back and forth along a first path P1 as the sipe molding member extends in the direction of the sipe molding member height H30 (or length L30). A further step of such a method includes removing the sipe molding member, leaving the sipe in the tread, with the sipe having the voids molded as the sipe molding member and a plurality of protrusions corresponding to the plurality of protrusions disposed along the sipe molding member.

[0049] It is understood that the sipe molding member may include any configuration desired by one skilled in the art for use with any known molding device. For example, in a particular example, as shown in one exemplary embodiment in Figures 3-10, the sipe molding member 30 includes a thick sipe molding portion 40 that surrounds at least a portion of a thin sipe molding portion 42. In these embodiments, both the thick and thin portions include corrugations along the sipe length, in addition to the thin portion being corrugated along the sipe length and height. In other variations, such as those shown in Figures 1, 2, and 11-13, only the thin portion of the sipe includes the surface corrugations described herein. It is clear that the thick sipe molding portion is thicker than the thin sipe molding portion. In different variations, the thick molding portion can partially or completely surround the thin sipe molding portion.

[0050] Corrugations formed by protrusions 36, particularly circular protrusions as shown in the embodiments illustrated herein, have been shown to produce tires with superior wear results. Comparative tests were conducted comparing tires with tread patterns molded using puzzle-type structures. Tires with sipes similar to those shown in FIGS. 11-13 were compared to tires with sipes having smooth surfaces (no corrugations). Tires with sipes formed by the sipe-molding members shown in FIGS. 11-13 demonstrated a 10% improvement in wear rate over the tire's wear life when compared to non-corrugated sipes, without significant changes in other tire performance. Such improved results are surprising because conventional tire molds that achieve such results require corrugated sipes, which require a more complex molding process that allows mold release and mold negative, or require welding of the sipe-molding member 30 to the mold that forms the tire, both of which add additional cost to the mold and the final product. The use of this technology results in complex sipe designs in tires made from economically manufactured puzzle molds.

[0051] It is understood that any tread discussed herein may be disposed along an annular pneumatic tire or formed separately from the tire as a tire component for later installation on a tire carcass according to any technique or process known to those skilled in the art. For example, the treads described and referenced herein may be molded with a new original tire or formed as a retread for later installation on a used tire carcass during a retreading operation. Thus, when referring to a tire tread, the longitudinal direction of the tire tread is synonymous with the circumferential direction of the tire when the tread is installed on the tire. Similarly, the tread width direction is synonymous with the tire axial direction or the tire width direction when the tread is installed on the tire. Finally, the tread thickness direction is synonymous with the radial direction of the tire when the tread is installed on the tire. It is understood that the tread of the present invention can be used with any known tire, which may include, for example, pneumatic or non-pneumatic tires.

[0052] Selected combinations of aspects of the disclosed technology correspond to multiple different embodiments of the present invention. It should be noted that each exemplary embodiment presented and described herein should not imply a limitation of the present subject matter. Features or steps illustrated or described as part of one embodiment may be used in combination with aspects of another embodiment to produce a further embodiment. Additionally, certain features may be interchangeable with similar devices or features not expressly mentioned that perform the same or similar function.

[0053] The terms "a," "an," and singular words should be construed to include plural forms of the same word, such that the term means that more than one of something is provided. The terms "at least one" and "one or more" are used interchangeably. A range described as being "between a and b" includes the values ​​"a" and "b."

[0054] The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein, or that it alone, or in combination with any other reference, refers to, teaches, suggests, or discloses such invention. Furthermore, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall control.

Claims

1. A tire mold, A plurality of mold parts, each mold part comprising: a mold part length extending longitudinally, the longitudinal direction being a circumferential direction when the mold parts are arranged to form an assembled tire mold; and a mold part width extending in a lateral direction, the lateral direction being perpendicular to the mold part length direction; a plurality of mold parts having a mold part thickness extending in a depth direction from an outer tread forming surface of the mold, the depth direction being perpendicular to both the mold part length direction and the mold part width direction; a plurality of sipe molding members, each having a sipe molding member length extending at least partially in the direction of the mold part length or width, a sipe molding member height extending at least partially in the direction of the mold part thickness and perpendicular to the length, and a sipe molding member thickness, each sipe molding member extending from the mold part surface in the mold part thickness direction; each of the plurality of sipe molding members has a thick sipe molding portion having a thickness and a thin sipe molding portion located within the thick sipe molding portion, the thin sipe molding portion having a thickness smaller than the thickness of the thick sipe molding portion; At least one of the opposing sides of the sipe molding member includes a plurality of projections located on the thin sipe molding portion, the plurality of projections being spaced apart, each projection forming a corrugation in the height direction of the sipe molding member, the corrugation having an amplitude equal to or less than the thickness of the thick sipe molding portion; a tire mold wherein one or more of the opposing sides of the sipe mold member thickness includes a plurality of recesses, the plurality of recesses being spaced apart, each recess forming a corrugation in the height direction of the sipe mold member, the corrugation having an amplitude less than or equal to the thickness of the thick sipe mold portion.

2. 2. The tire mold of claim 1, wherein the plurality of projections are arranged in rows, adjacent rows being shifted relative to one another such that each projection of any row is positioned adjacent one of the recesses of an adjacent row.

3. 3. The tire mold of claim 1, wherein the projections and recesses are formed along the thickness of the sipe and corrugate back and forth along a non-linear corrugation path as the sipe extends in the direction of the sipe height or sipe length, the non-linear corrugation path forming a plurality of corrugations having a period of 1.0 to 2.4 millimeters and an amplitude equal to or less than the thickness of the thick sipe molding portion.

4. 4. The tire mold of claim 1, wherein the other of the opposing sides of the sipe thickness includes a plurality of projections, the plurality of projections being spaced apart and each having a height dimension equal to or less than the thickness of the thick sipe molding portion.

5. 5. The tire mold of claim 1, wherein for each of the plurality of sipes, the plurality of projections and the plurality of recesses are arranged in an alternating projection-recess arrangement along the sipe length and sipe height, whereby the opposing sides of the tread are arranged in a mating configuration.

6. The tire mold of any one of claims 1 to 5, wherein the thickness of the thick sipe molding portion is measured in the range of 0.3 mm to 0.9 mm.

7. The tire mold of any one of claims 1 to 6, wherein the thickness of the thinned portion is measured in the range of 0.15 mm to 0.4 mm.

8. 1. A method of making a tire mold, comprising: placing a sipe molding member within the slot of the mold negative; placing mold material into the mold negative to form a mold part; and removing the mold part from the mold negative with the sipe molding member embedded in the mold part. The mold part is a mold part length extending longitudinally, the longitudinal direction being a circumferential direction when the mold parts are arranged to form an assembled tire mold; and a mold part width extending in a lateral direction, the lateral direction being perpendicular to the mold part length direction; a mold part thickness extending in a depth direction from an outer tread forming surface of the mold, the depth direction being perpendicular to both the mold part length direction and the mold part width direction; The sipe molding member is a sipe molding member length extending at least partially in the direction of the mold part length or the mold part width, a sipe molding member height extending at least partially in the direction of the mold part thickness and perpendicular to the sipe molding member length, and a sipe molding member thickness, each sipe molding member extending from the mold part surface in the mold part thickness direction; the sipe molding member has a thick sipe molding portion having a thick sipe molding portion thickness, and a thin sipe molding portion located within the thick sipe molding portion and having a thin sipe molding portion thickness that is smaller than the thickness of the thick sipe molding portion; at least one of the opposing sides of the sipe molding member includes a plurality of projections located on the thin sipe molding portion, the plurality of projections being spaced apart, each projection forming a corrugation in the height direction of the sipe molding member, the corrugation having an amplitude equal to or less than the thickness of the thick sipe molding portion; one or more of the opposing sides of the sipe molding member thickness includes a plurality of recesses, the plurality of recesses being spaced apart, each recess forming a corrugation in the height direction of the sipe molding member, the corrugation having an amplitude less than or equal to the thickness of the thick sipe molding portion; 1. A method of making a tire mold, wherein the thick sipe molding portions engage the slots in the mold negative such that the mold material does not reach the thin sipe molding portions when the mold material is placed in the mold negative.

9. 10. The method of making a tire mold of claim 8, wherein placing the mold material into the mold is performed by casting.

10. 10. The method of making a tire mold of claim 8 or 9, wherein the plurality of protrusions are arranged in rows, adjacent rows being shifted relative to one another so that each protrusion in any row is positioned adjacent one of the recesses in an adjacent row.

11. 11. The method of making a tire mold of any one of claims 8 to 10, wherein the protrusions and recesses are formed along the sipe thickness, and the sipe further corrugates back and forth along a non-linear corrugation path as it extends in the direction of the sipe height or sipe length, the non-linear corrugation path forming a plurality of corrugations having a period of 1.0 to 2.4 millimeters and an amplitude equal to or less than the thickness of the thick sipe molding portion.

12. 11. The method of making a tire mold according to claim 8, wherein the other of the opposing sides of the sipe thickness includes a plurality of projections, the plurality of projections being spaced apart and each having a height dimension less than or equal to the thickness of the thick sipe molding portion.

13. 11. The method of making a tire mold of any one of claims 8 to 10, wherein for each of the plurality of sipes, the plurality of projections and the plurality of recesses are arranged in an alternating projection-recess arrangement along the length and height of the sipe, whereby the opposing sides of the tread are arranged in a mating configuration.

14. 14. The method of making a tire mold according to any one of claims 8 to 13, wherein the thickness of the thick sipe molding portion measures in the range of 0.3 mm to 0.9 mm.

15. A method of making a tire mold according to any one of claims 8 to 13, wherein the thickness of the thinned portion is measured in the range of 0.15 mm to 0.4 mm.

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