Directional interconnecting sipes and / or slots

Abstract

In one aspect, a tire is provided, the tire comprising: a tread portion including at least one of a tread rib or a tread block; and a sipe included in the tread rib or tread block, the sipe including a central S-shaped portion axially located between opposing laterally extending straight portions, the sipe including a plurality of key portions inclined in a first circumferential direction, the sipe including a plurality of return portions inclined in a second circumferential direction, the return portions connecting the key portions, the first key portion intersecting a tread surface of the tread rib or tread block, the plurality of key portions inclined at an angle KA, and the plurality of return portions inclined at an angle RA, the ratio of the angle KA to the angle RA being at least 5:1.

Description

[Background technology]

[0001] Tires are often designed to optimize performance in various road conditions. For example, a tire may include tread features designed to optimize performance in snowy / icy road conditions and dry road conditions.

[0002] Gaining traction in snow and ice can be achieved by providing "biting edges" in the tire tread. These "biting edges" are often in the form of sipes or slots. However, too many sipes or slots can cause the tread blocks or ribs to lose rigidity, which may not be desirable for optimal tire performance, especially in dry road conditions. Summary of the Invention [Problem to be solved by the invention]

[0003] Therefore, what is needed is a tire tread feature that balances traction on snow and ice with traction on dry roads.

[0004] In one aspect, a tire is provided, the tire comprising: a tread portion including at least one of a tread rib or a tread block; and a sipe included in the tread rib or tread block, the sipe including a central S-shaped portion axially located between opposing laterally extending straight portions, the sipe including a plurality of key portions inclined in a first circumferential direction, the sipe including a plurality of return portions inclined in a second circumferential direction, the return portions connecting the key portions, the first key portion intersecting a tread surface of the tread rib or tread block.

[0005] In another aspect, a tire is provided comprising: a tread portion including at least one of a tread rib or a tread block; and a sipe included in the tread rib or tread block, the sipe including a plurality of key portions inclined in a first circumferential direction at an angle KA from a circumferential direction tangential to the tread surface; and the sipe including a plurality of return portions inclined in a second circumferential direction at an angle RA from the circumferential direction tangential to the tread surface, the return portions connecting the key portions; and the first key portion intersecting the tread surface of the tread rib or tread block, wherein a ratio of the angle KA to the angle RA is at least 5:1.

[0006] In another aspect, a tire sipe blade is provided, the tire sipe blade including an upper mold insert portion, a plurality of key portions inclined in a first circumferential direction at an angle KA, and a plurality of return portions inclined in a second circumferential direction at an angle RA, the return portions connecting the key portions and the first key portions connecting to the upper mold insert portion, wherein a ratio of the angle KA to the angle RA is at least 5:1. [Brief explanation of the drawings]

[0007] The accompanying figures, which are incorporated in and constitute a part of this specification, illustrate various exemplary aspects and are used only to illustrate various exemplary aspects, in which like elements have like reference numerals. [Figure 1] FIG. 1 shows a plan view of a tire tread 100 having tread blocks 106 with directional interlocking sipes and / or slots 110 . [Figure 2A] FIG. 2A shows an elevational cross-sectional view of a sipe blade 230 for forming directional interlocking sipes and / or slots. [Figure 2B] FIG. 2B shows an elevational cross-sectional view of a sipe blade 230 for forming directional interlocking sipes and / or slots. [Figure 2C] FIG. 2C shows an elevational cross-sectional view of a sipe blade 230 for forming directional interlocking sipes and / or slots. [Figure 2D] FIG. 2D shows an elevational cross-sectional view of another arrangement of sipe blades 230 to form directional interlocking sipes and / or slots. [Figure 2E] FIG. 2E shows a perspective view of a sipe blade 230 for forming directional interlocking sipes and / or slots. [Figure 2F] FIG. 2F shows a perspective view of a sipe blade 230 for forming directional interlocking sipes and / or slots. [Figure 3A] FIG. 3A shows a perspective view of a tread block 306 having directional interlocking sipes and / or slots 310. [Figure 3B] FIG. 3B shows an elevation view of a tread block 306 having directional interlocking sipes and / or slots 310. [Figure 3C] FIG. 3C shows a top view of a tread block 306 having directional interlocking sipes and / or slots 310. [Figure 3D] FIG. 3D shows an exploded perspective view of a tread block 306 having directional interlocking sipes and / or slots 310. [Figure 3E] FIG. 3E shows a partial perspective view of a tread block 306 having directional interlocking sipes and / or slots 310. [Figure 4A] FIG. 4A shows a partial elevation view of a tread block 406 having directional interlocking sipes and / or slots 410. [Figure 4B] FIG. 4B shows a partial elevation view of a tread block 406 having directional interlocking sipes and / or slots 410. [Figure 4C] FIG. 4C shows a partial elevation view of a tread block 406 having directional interlocking sipes and / or slots 410. [Figure 4D] FIG. 4D shows a partial elevation view of a tread block 406 having directional interlocking sipes and / or slots 410. DETAILED DESCRIPTION OF THE INVENTION

[0008] The axes and planes described herein are shown in the figures and include a circumferential axis C oriented in the circumferential direction of the tire, a radial axis R oriented in the radial direction of the tire, and an axial axis A oriented in the axial direction of the tire.

[0009] 1 shows a tire tread 100 having tread blocks 106 with directional, interconnecting sipes and / or slots 110. The tread 100 includes a tread surface 101, which is the radially outer surface of the tread 100 that contacts the driving surface. The tread 100 may include a plurality of blocks 106 oriented in block rows defined by one or more circumferential grooves 104, the block rows including, for example, a shoulder row 160, a median row 162, and one or more center rows 164. Alternatively, the tire tread 100 may include ribs (defined by one or more circumferential grooves 104) instead of individual blocks 106, with the ribs oriented in the aforementioned shoulder, medial, and center orientations.

[0010] The tire tread 100 includes one or more directional, interconnecting sipes and / or slots 110. The sipes and / or slots 110 may include axially oriented central S-shaped portions 112 between laterally extending straight portions 114. The sipes and / or slots 110 may include only straight portions 114, as shown, for example, in only the shoulder rows 160 of the exemplary tire tread 100. The tire tread 100 may include sipes and / or slots 110 in each row (with or without the central S-shaped portion 112). It is contemplated that these alternative sipe and / or slot arrangements 110 may be included in different block rows 160, 162, 164, as shown, or may be mixed within the same block row 160, 162, 164, or even within the same block 106.

[0011] For the sake of brevity and readability, the term "sipe" as used herein is intended to refer to sipes and / or slots, which may refer to any small cuts in a tread block or rib and / or any small lateral grooves that circumferentially separate tread blocks or divide tread ribs. The use of the term "sipe" is not intended to exclude slots as used herein.

[0012] 2A-2F illustrate various possible embodiments of sipe blades 230 for forming directional interlocking sipes and / or slots, including, for example, sipes and / or slots 110 shown in FIG.

[0013] Sipe blade 230 includes an upper mold insert portion 232 and a lower sipe forming portion 234 .

[0014] The upper portion 232 includes a centerline CL. The upper portion 232 includes a circumferential tread surface sipe width TSW, which is the width of a sipe (e.g., sipe and / or slot 110) on the tread surface (e.g., tread surface 101). The width TSW may be about 0.60 mm. The width TSW may be 0.60 mm. The width TSW may be about 0.50 mm to about 0.70 mm. The width TSW may be 0.50 mm to 0.70 mm. The width TSW may be about 0.40 mm to about 0.80 mm. The width TSW may be 0.40 mm to 0.80 mm. The width TSW may be about 0.30 mm to about 0.90 mm. The width TSW may be 0.30 mm to 0.90 mm.

[0015] The lower portion 234 includes a plurality of key portions 236. A first key portion 236 is radially inward of and directly connected to the upper portion 232. Each key portion 236 is connected to another key portion 236 by a return portion 238.

[0016] In one aspect, the lower portion 234 includes, at its radially outermost position (immediately radially inward of the upper portion 232), a first key portion 236 having a first return portion 238 extending radially inward therefrom, a second key portion 236 extending radially inward from the first return portion 238 and having a second return portion 238 extending radially inward therefrom, and finally, a third key portion 236 extending radially inward from the second return portion 238.

[0017] Each key portion 236 is inclined at an angle KA from the circumferential direction, measured tangentially to the tread surface (e.g., tread surface 101). Each key portion 236 is inclined in the same direction (e.g., in a first circumferential direction). The angle KA may be approximately 60 degrees. The angle KA may be 60 degrees. The angle KA may be between approximately 55 degrees and approximately 65 degrees. The angle KA may be between 55 degrees and 65 degrees. The angle KA may be between approximately 50 degrees and approximately 70 degrees. The angle KA may be between 50 degrees and 70 degrees. The angle KA may be between 45 degrees and approximately 75 degrees. The angle KA may be between 45 degrees and 75 degrees.

[0018] Each return portion 238 is inclined at an angle RA from the circumferential direction, measured tangentially to the tread surface (e.g., tread surface 101). Each return portion 238 is inclined in the same direction (e.g., a second circumferential direction) opposite to the direction of each key portion 236 (e.g., a first circumferential direction). The angle RA may be approximately 11 degrees. The angle RA may be 11 degrees. The angle RA may be between approximately 9 degrees and approximately 15 degrees. The angle RA may be between 9 degrees and 15 degrees. The angle RA may be between approximately 7 degrees and approximately 19 degrees. The angle RA may be between 7 degrees and 19 degrees. The angle RA may be between approximately 5 degrees and approximately 23 degrees. The angle RA may be between 5 degrees and 23 degrees.

[0019] The ratio of angle KA to angle RA is at least 5:1. The ratio of angle KA to angle RA is between 5:1 and 6:1.

[0020] Each key portion 236 includes a width KW. The width KW is measured transversely to the longitudinal direction of each key portion 236 (at 90 degrees from the longitudinal direction). The width KW may be approximately 0.30 mm. The width KW may be 0.30 mm. The width KW may be approximately 0.25 mm to approximately 0.40 mm. The width KW may be 0.25 mm to 0.40 mm. The width KW may be approximately 0.20 mm to approximately 0.50 mm. The width KW may be 0.20 mm to 0.50 mm. The width KW may be approximately 0.15 mm to approximately 0.60 mm. The width KW may be 0.15 mm to 0.60 mm.

[0021] Each return portion 238 includes a width RW. The width RW is measured transversely to the longitudinal direction of each return portion 238 (at 90 degrees from the longitudinal direction). The width RW may be approximately 0.40 mm. The width RW may be 0.40 mm. The width RW may be approximately 0.35 mm to approximately 0.50 mm. The width RW may be 0.35 mm to 0.50 mm. The width RW may be approximately 0.30 mm to approximately 0.60 mm. The width RW may be 0.30 mm to 0.60 mm. The width RW may be approximately 0.25 mm to approximately 0.70 mm. The width RW may be 0.25 mm to 0.70 mm.

[0022] The ratio of width KW to width RW may be 3:4.

[0023] The first key portion 236 joins the first return portion 238 at a first apex that is a radial height KH1 from a tread surface (the junction between the upper portion 232 and the lower portion 234), such as tread surface 101.

[0024] In the embodiment shown in FIG. 2A, the height KH1 may be approximately 2.76 mm. The height KH1 may be 2.76 mm. The height KH1 may be approximately 2.50 mm to approximately 3.00 mm. The height KH1 may be 2.50 mm to 3.00 mm. The height KH1 may be approximately 2.00 mm to approximately 3.50 mm. The height KH1 may be 2.00 mm to 3.50 mm. The height KH1 may be approximately 1.50 mm to approximately 4.00 mm. The height KH1 may be 1.50 mm to 4.00 mm. FIG. 2A may be a sipe blade 230 for forming sipes and / or slots in, for example, a shoulder rib or shoulder block row (e.g., shoulder row 160).

[0025] In the embodiment shown in FIG. 2B, the height KH1 may be approximately 2.17 mm. The height KH1 may be 2.17 mm. The height KH1 may be approximately 2.00 mm to approximately 2.50 mm. The height KH1 may be 2.00 mm to 2.50 mm. The height KH1 may be approximately 1.50 mm to approximately 3.00 mm. The height KH1 may be 1.50 mm to 3.00 mm. The height KH1 may be approximately 1.00 mm to approximately 3.5 mm. The height KH1 may be 1.00 mm to 3.50 mm. FIG. 2B may be a sipe blade 230 for forming sipes and / or slots, for example, in a mid-rib or mid-block row (e.g., mid-row 162).

[0026] In the embodiment shown in FIG. 2C, the height KH1 may be approximately 1.48 mm. The height KH1 may be 1.48 mm. The height KH1 may be approximately 1.25 mm to approximately 1.75 mm. The height KH1 may be 1.25 mm to 1.75 mm. The height KH1 may be approximately 1.00 mm to approximately 2.00 mm. The height KH1 may be 1.00 mm to 2.00 mm. The height KH1 may be approximately 0.75 mm to approximately 2.25 mm. The height KH1 may be 0.75 mm to 2.25 mm. FIG. 2C may be a sipe blade 230 for forming sipes and / or slots in, for example, a central rib or central block row (e.g., central row 164).

[0027] The second key portion 236 joins the second return portion 238 at a second apex that is a radial height KH2 from the first apex.

[0028] In the embodiment shown in FIG. 2A, the height KH2 may be about 2.17 mm. The height KH2 may be 2.17 mm. The height KH2 may be about 2.00 mm to about 2.50 mm. The height KH2 may be 2.00 mm to 2.50 mm. The height KH2 may be about 1.50 mm to about 3.00 mm. The height KH2 may be 1.50 mm to 3.00 mm. The height KH2 may be about 1.00 mm to about 3.5 mm. The height KH2 may be 1.00 mm to 3.50 mm. The ratio of KH1 to KH2 may be about 1.27, may be 1.27, may be about 1.20 to about 1.30, may be 1.20 to 1.30, may be about 1.15 to about 1.35, may be 1.15 to 1.35, may be about 1.10 to about 1.40, may be 1.10 to 1.40.

[0029] In the embodiment shown in FIG. 2B, the height KH2 may be about 2.17 mm. The height KH2 may be 2.17 mm. The height KH2 may be about 2.00 mm to about 2.50 mm. The height KH2 may be 2.00 mm to 2.50 mm. The height KH2 may be about 1.50 mm to about 3.00 mm. The height KH2 may be 1.50 mm to 3.00 mm. The height KH2 may be about 1.00 mm to about 3.5 mm. The height KH2 may be 1.00 mm to 3.50 mm. The ratio of KH1 to KH2 may be about 1.00, may be 1.00, may be about 0.95 to about 1.05, may be 0.95 to 1.05, may be about 0.90 to about 1.10, may be 0.90 to 1.10, may be about 0.85 to about 1.15, may be 0.85 to 1.15.

[0030] In the embodiment shown in FIG. 2C, the height KH2 may be about 2.17 mm. The height KH2 may be 2.17 mm. The height KH2 may be about 2.00 mm to about 2.50 mm. The height KH2 may be 2.00 mm to 2.50 mm. The height KH2 may be about 1.50 mm to about 3.00 mm. The height KH2 may be 1.50 mm to 3.00 mm. The height KH2 may be about 1.00 mm to about 3.5 mm. The height KH2 may be 1.00 mm to 3.50 mm. The ratio of KH1 to KH2 may be about 0.68, may be 0.68, may be about 0.65 to about 0.70, may be 0.65 to 0.70, may be about 0.60 to about 0.75, may be 0.60 to 0.75, may be about 0.55 to about 0.80, may be 0.55 to 0.80.

[0031] Sipe blade 230 terminates radially inward at end portion 239. In one embodiment, centerline CL extends through end portion 239. In another embodiment, centerline CL may extend through end portion 239. End portion 239 may include a circumferential width that is half of width TSW.

[0032] FIG. 2D shows sipe blades 230A (FIG. 2A), 230B (FIG. 2B), and 230C (FIG. 2C) side-by-side. The first and second apex heights and the values ​​of KH1 and KH2 vary between each sipe blade. The key edge (e.g., key edge 350) formed in the tread by the sipe blade is present while the tread wears along key portion 236, but is absent during the brief period when the tread wears through return portion 238. As shown, the sipe blades may be configured such that the first and second apex heights and the values ​​of KH1 and KH2 are offset to ensure the presence of the key edge during tire wear.

[0033] As shown in FIG. 2E, the sipe blade 230 may include an axially oriented central S-shaped portion 242 between laterally extending straight portions 244.

[0034] As shown in FIG. 2F, the sipe blade 230 may not include a central S-shaped portion, but may include only a laterally extending straight portion 244.

[0035] 3A-3E show a tread block 306 having directional interlocking sipes and / or slots 310.

[0036] The sipes and / or slots 310 extend radially inward from the tread surface 301 into the tread blocks 306. The sipes and / or slots 310 may include an axially oriented central S-shaped portion 312 between laterally extending straight portions 314. The sipes and / or slots 310 may include only straight portions 314, as shown, for example, in only the shoulder row 160 of the exemplary tire tread 100 in FIG.

[0037] The sipe and / or slot 310 includes a key portion 346 and a return portion 348 as described above with respect to the key portion 236 and return portion 238 of the sipe blade 230 .

[0038] The key portions 346 form sharp (acute) key edges 350 where the key portions 346 meet the tread surface 301. The key edges 350 increase traction when the tread blocks 306 engage the road in the rolling direction DR. The key edges 350 increase traction on snow and / or ice by increasing friction between the tread surface 301 and the snow- and / or ice-covered riding surface. The key edges 350 provide the benefit of increasing traction by "biting" into snow and ice surfaces, which can increase traction on these surfaces during acceleration in the rolling direction DR. The key edges 350 form an angle KA (as noted above in FIGS. 2A-2C ) with the tread surface 301.

[0039] 4A-4D show a tread block 406 having directional interlocking sipes and / or slots 410 at various stages of wear.

[0040] 4A and 4B show the tread surface 401 of the tread block 406 wearing through the first key portion 446. The key edge 450 is present at these stages of wear of the tread block 406. That is, as the tread block 406 wears, the tread surface 401 moves radially inward and intersects a different portion of the sipe and / or slot 410.

[0041] FIG. 4C shows the tread surface 401 wearing through the first return portion 448 which does not include the key edge 450.

[0042] FIG. 4D shows the tread surface 401 wearing through the second key portion 446, in which the key edge 450 is again present.

[0043] Due to the difference between the angle of key portion 446 (e.g., angle KA) and the angle of return portion 448 (e.g., angle RA), as tread surface 401 wears radially inward, sipes and / or slots 410 intersect tread surface 401 at key portion 446 for a longer period of wear than at return portion 448. As shown, sipes and / or slots 410 include key edges 450, and key portions 446 intersect tread surface 401.

[0044] With regard to the various aspects described above, tire treads having sipes and / or slots with keyed edges as described herein have improved traction in snow and / or ice compared to tire treads lacking such features. Treads with keyed edges as described herein may have the benefit of increased traction on snow in the forward rolling (acceleration) direction DR compared to standard snow tires. Alternatively, the described keyed edges may have the benefit of increased traction on snow in the rearward rolling (braking) direction DR compared to standard snow tires, depending on the orientation of the sipes and / or slots.

[0045] Prior art designs have attempted to increase snow traction through tread patterns and void patterns (i.e., axially extending) with very high lateral edge densities, which results in poor performance on dry roads. The sipes and / or slots described herein significantly improve snow performance and allow for modification of the tread pattern to reduce lateral edge densities, thus reducing and / or eliminating the detrimental effects on dry performance. As a result, tread patterns with the above-described sipes and / or slots have additional snow and dry performance compared to tread patterns without the above-described sipes and / or slots. Additionally, with different values ​​of KH1 and KH2 between various sipes and / or slots, improved snow traction can be present at any wear condition of the tread pattern.

[0046] Additionally, the alternating key and return configuration of the sipes and / or slots described herein creates interconnected sipe sidewalls that are self-touching (interlocking) under braking, acceleration, and lateral steering. This interconnected aspect of the tread blocks may act to increase the stiffness of the blocks under braking, acceleration, and / or lateral steering.

[0047] To the extent the term "includes" or "including" is used in this specification or the claims, the term "comprising" is intended to be inclusive, similar to the way that the term is interpreted when used as a transitional term in a patent claim. Furthermore, to the extent the term "or" is used (e.g., A or B), it is intended to mean "A or B, or both." Where applicants intend to indicate "only A or B but not both," the term "only A or B but not both" is used. Thus, the use of the term "or" herein is inclusive, not exclusive. See Bryan A. Garner, A Dictionary of Modern Legal Usage 624 (2d. Ed. 1995). Also, to the extent the term "in" or "into" is used in this specification or the claims, it is intended to additionally mean "on" or "onto." To the extent the term "substantially" is used herein or in the claims, it is intended to take into account the degree of precision available in tire manufacturing. To the extent the term "selectively" is used herein or in the claims, it is intended to refer to a condition of components in which a user of the device can activate or deactivate a feature or function of the component as needed or desired during use of the device. To the extent the term "operably connected" is used herein or in the claims, it is intended to mean that the identified components are connected to perform the specified function. As used herein and in the claims, the singular forms "a," "an," and "the" include the plural. Finally, when the term "about" is used in conjunction with a numerical value, it is intended to encompass ±10% of that numerical value. In other words, "about 10" can mean from 9 to 11.

[0048] As noted above, the present application has been illustrated by descriptions of embodiments and aspects thereof, and while the embodiments and aspects have been described in considerable detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such details. Additional advantages and modifications will be readily apparent to those skilled in the art with the benefit of this application. Accordingly, the present application, in its broader aspects, is not limited to the specific details, examples shown, or any devices referenced. Departures may be made from such details, examples, and devices without departing from the spirit or scope of the general inventive concept.

Claims

1. a tread portion comprising at least one of a tread rib or a tread block; and A tire comprising a sipe included in the tread rib or the tread block, The sipe includes a plurality of key portions inclined at an angle KA from a circumferential direction of the tire, which is a tangential direction to the tread surface, to a depth direction of the tread portion, The sipe includes a plurality of return portions inclined at an angle RA from the circumferential direction, which is a tangential direction to the tread surface, to the depth direction, the return portion connects the key portions together; a first key portion intersecting the tread surface of the tread rib or the tread block; A tire wherein each key portion has a width KW and each return portion has a width RW, the ratio of said width KW to said width RW being 3:

4.

2. 10. The tire of claim 1, wherein said sipe includes a central S-shaped portion axially disposed between opposing, laterally extending straight portions.

3. The tire of claim 1 , wherein the first key portion intersects the tread surface to form a key edge.

4. 2. The tire of claim 1, further comprising a sipe that does not include a central S-shaped portion and includes only laterally extending straight portions, said sipe including said plurality of key portions, said sipe including said plurality of return portions, said return portions connecting said key portions, and a first key portion intersecting a tread surface of said tread rib or said tread block.

5. A tire as described in claim 1, wherein the ratio of the angle KA to the angle RA is between 5:1 and 6:1.

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