Bidirectional sipes and / or slots

Abstract

In one aspect, a tire is provided that includes a tread portion including tread ribs or tread blocks and sipes included in the tread ribs or tread blocks, the sipes including a central section axially located between opposing outer sections, the central section and each outer section including a radially outer portion and a radially inner portion, the radially outer portion of each outer section having a circumferential width WT1, the radially outer portion of the central section having a circumferential width WT2, the circumferential width WT1 being greater than the circumferential width WT2, the radially inner portion of each outer section including an axially outer portion having a radial depth DB1E and an axially inner portion having a radial depth DB1I, the radial depth DB1E being less than the radial depth DB1I.

Description

[Background technology]

[0001] Tires are often designed to optimize performance in various road conditions, for example, an all-weather tire may include tread features designed to optimize performance in dry, wet, and snowy / icy road conditions.

[0002] Gaining traction on snow and ice is often 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 lead to a loss of stiffness in the tread blocks or ribs, which may be undesirable for optimal tire performance, especially in dry roadway 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 roadways.

[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 the tread block, the sipe including a central section axially located between opposing outer sections, the central section and each outer section including a radially outer portion and a radially inner portion, the radially outer portion of each outer section having a circumferential width WT1, the radially outer portion of the central section having a circumferential width WT2, the circumferential width WT1 being greater than the circumferential width WT2, the radially inner portion of each outer section including an axially outer portion having a radial depth DB1E and an axially inner portion having a radial depth DB1I, the radial depth DB1E being less than the radial depth DB1I.

[0005] In another aspect, a tire is provided that includes a tread portion including at least one of a tread rib or a tread block, and a sipe included in the tread rib or the tread block, the sipe including a central section axially located between opposing outer sections, the central section and each outer section including a radially outer portion and a radially inner portion, the radially outer portion of each outer section having a circumferential width WTI, the radially outer portion of the central section having a circumferential width WTI greater than the circumferential width WTI, the radially inner portion of each outer section having a circumferential width WBI less than the width WBI, the radially inner portion of the central section having a circumferential width WBI greater than the width WTI, the circumferential width WBI less than the circumferential width WBI, and the width WBI less than the width WBI.

[0006] In another aspect, a tire sipe blade is provided, the tire sipe blade including a central section axially positioned between opposing outer sections, the central section and each outer section including a radially outer portion and a radially inner portion, the radially outer portion of each outer section having a circumferential width WT1, the radially outer portion of the central section having a circumferential width WT2, the circumferential width WT1 being greater than the circumferential width WT2, the radially inner portion of each outer section including an axially outer portion having a radial depth DB1E and an axially inner portion having a radial depth DB1I, the radial depth DB1E being less than the radial depth DB1I. [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 1A] FIG. 1A shows a perspective view of a tire tread 100 having tread blocks 106 that include bidirectional sipes and / or slots 110. [Figure 1B]FIG. 1B shows a plan view of a tire tread 100 having tread blocks 106 that include bidirectional sipes and / or slots 110. [Figure 1C] FIG. 1C shows a perspective view of a tread block 106 including bidirectional sipes and / or slots 110. [Figure 1D] FIG. 1D shows a perspective view of half of a tread block 106 including bidirectional sipes and / or slots 110. [Figure 1E] FIG. 1E shows a perspective view of half of a tread block 106 including bidirectional sipes and / or slots 110. [Figure 2A] FIG. 2A shows a perspective view of a tire sipe blade 230 for forming bidirectional sipes and / or slots. [Figure 2B] FIG. 2B shows an elevation view of a tire sipe blade 230 for forming bidirectional sipes and / or slots. [Figure 2C] FIG. 2C shows a cross-sectional view of a tire sipe blade 230 taken about the plane formed by reference line AA in FIG. 2B. [Figure 2D] FIG. 2D shows a cross-sectional view of tire sipe blade 230 taken about the plane formed by reference line BB in FIG. 2B. [Figure 2E] FIG. 2E shows a cross-sectional view of tire sipe blade 230 taken about the plane formed by reference line CC in FIG. 2B. [Figure 2F] FIG. 2F shows a plan view of a tire sipe blade 230 for forming bidirectional sipes and / or slots. DETAILED DESCRIPTION OF THE INVENTION

[0008] 1A-1E show a tire tread 100 having tread blocks 106 that include bidirectional sipes and / or slots 110. The tire tread 100 may be utilized in any of a variety of tires, including, for example, tires intended for use on both dry and snowy and icy riding surfaces.

[0009] The axes and planes described herein are shown in Figures 1A-1E 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.

[0010] The tire tread 100 may include at least one row of blocks 102 defined by parallel circumferential grooves 104. Axial slots / sipes 108 may extend at least partially across the row of blocks 102 to define individual tread blocks 106. At least one tread block 106 includes bidirectional sipes and / or slots 110. Alternatively, the tire tread 100 may include at least tread ribs instead of tread blocks, and the tread ribs include bidirectional sipes and / or slots 110.

[0011] The sipe / slot 110 includes a central section 112 located between (e.g., axially between) opposing outer sections 114. The sipe / slot 110 includes opposing key edges 116 defined in the central section 112. The key edges 116 are at a negative or undercut angle with respect to the radial direction R on their radially outer surfaces, such that the blocks 106 have opposing inward-facing acute angles at their radially outer portions.

[0012] The opposing key edges 116 provide bidirectionality (i.e., the tire does not need to have a specific direction of rotation) that provides increased traction on snow and ice. The bidirectionality of the opposing key edges 116 allows the tire to function as intended regardless of the direction of tire rotation, thereby allowing installers to mount the tire on a vehicle with the tread rotating in either direction without degrading tire performance. Additionally, the bidirectionality of the opposing key edges 116 may provide traction benefits on snow and ice both when the tire is accelerating and when braking. That is, the sharp key edges 116 "bite" into snowy and icy surfaces, increasing the tire's traction on those surfaces. The shape of the key edges 116 is most easily seen in FIG. 1E.

[0013] The sipe / slot 110 includes opposed chamfered edges 118 defined in the outer section 114. The chamfered edges 118 are at a radially outer surface and are at a regular angle relative to the radial direction R. That is, the chamfered edges 118 are angled in the opposite direction from the keyed edges 116. The shape of the chamfered edges 118 can be most easily seen in FIG. 1E.

[0014] Opposing sidewalls 120 of the outer section extend radially inward from chamfered edge 118 to an outer base 122 substantially in the radial direction R. Opposing sidewalls 124 of the central section extend radially inward from keyed edge 116 to a central base 126 substantially in the radial direction R.

[0015] The outer section 114 may include a step caused by a short radial depth (D1E, described below) at the outermost outer portion and a long radial depth (D1I, described below) at the innermost inner portion. As a result, tie bars 129 are formed within the sipes / slots 110. The tie bars 129 may act to "connect" the two halves of the block 106 bisected by the sipes / slots 110, resulting in increased stiffness of the block 106.

[0016] The relative dimensions and angles of the sipes / slots 110 are outlined below with respect to the sipe blades 230.

[0017] 2A-2F show a tire sipe / slot blade 230 for forming bidirectional sipes and / or slots, such as sipe / slot 110. FIG.

[0018] Blade 230 includes a center section 232 located between (e.g., axially between) opposing outer sections 234. Center section 232 includes a top center section face 235, and each outer section 234 includes a top outer section face 237.

[0019] Blade 230 includes opposed keyed edges 236 confined to center section 232. Keyed edges 236 form a negative or undercut angle (key edge 116) with respect to radial direction R at the radially outer surface of tire tread 100, such that blocks 106 have opposed inwardly facing acute angles (key edge 116) at their radially outer portions. The shape of keyed edges 236 is most easily seen in Figures 2A and 2C-2E.

[0020] Blade 230 includes opposed chamfer-forming edges 238 defined on outer section 234. Chamfer-forming edges 238 form a right angle with respect to radial direction R on the radially outer surface. That is, chamfer-forming edges 238 are angled in the opposite direction from key-forming edges 236. The shape of chamfer-forming edges 238 can be most easily seen in Figures 2A and 2C-2E.

[0021] Outer section 234 includes outer section opposed sidewalls 240 that form sidewall 120. Sidewalls 240 extend downwardly from a chamfer-forming edge 238. Central section 232 includes central section opposed sidewalls 244 that form sidewall 124. Sidewalls 244 extend downwardly from key-forming edge 236.

[0022] The top outer section surface 237 includes a width (e.g., circumferential width) WT1. In one embodiment, the width WT1 is about 1.0 mm to about 3.0 mm. In another embodiment, the width WT1 is 1.0 mm to 3.0 mm. In another embodiment, the width WT1 is about 1.5 mm to about 2.5 mm. In another embodiment, the width WT1 is 1.5 mm to 2.5 mm. In another embodiment, the width WT1 is about 1.75 mm to about 2.25 mm. In another embodiment, the width WT1 is 1.75 mm to 2.25 mm. In another embodiment, the width WT1 is about 2.0 mm. In another embodiment, the width WT1 is 2.0 mm.

[0023] The top central section surface 235 includes a width (e.g., circumferential width) WT2. In one embodiment, the width WT2 is about 0.5 mm to about 2.0 mm. In another embodiment, the width WT2 is 0.5 mm to 2.0 mm. In another embodiment, the width WT2 is about 0.7 mm to about 1.8 mm. In another embodiment, the width WT2 is 0.7 mm to 1.8 mm. In another embodiment, the width WT2 is about 0.8 mm to about 1.5 mm. In another embodiment, the width WT2 is 0.8 mm to 1.5 mm. In another embodiment, the width WT2 is about 1.0 mm. In another embodiment, the width WT2 is 1.0 mm.

[0024] The width WT1 is greater than the width WT2. In one embodiment, the width WT1 is about 2.0 times the value of the width WT2. In another embodiment, the width WT1 is 2.0 times the value of the width WT2. In another embodiment, the width WT1 is 1.5 to 2.5 times the value of the width WT2.

[0025] The side walls 240 are separated (eg, circumferentially) by a width WB1.

[0026] The side walls 244 are separated (eg, circumferentially) by a width WB1.

[0027] The width WB1 is smaller than the width WT1. The width WB2 is larger than the width WT2. The width WB1 is smaller than the width WB2. In one embodiment, the width WB1 and the width WB2 are both smaller than the width WT1.

[0028] In one embodiment, the width WB1 is equal to the width WT2, and in another embodiment, the width WB2 is equal to the width WT1.

[0029] Each outer section 234 may include a length L1 (eg, axially).

[0030] Each outer section 234 may include an outermost portion having a short radial depth (D1E) and a length (e.g., axially) L1E, and an inner portion having a long radial depth (D1I) and a length L1I, where length L1 is equal to length L1E plus length L1I.

[0031] Figure 2C shows a cross-sectional view of tire sipe blade 230 taken about the plane formed by reference line AA in Figure 2B. Figure 2D shows a cross-sectional view of tire sipe blade 230 taken about the plane formed by reference line BB in Figure 2B. Figure 2E shows a cross-sectional view of tire sipe blade 230 taken about the plane formed by reference line CC in Figure 2B.

[0032] The outermost portion of each outer section 234 may include a total radial depth D1E, with the chamfer-forming edge 238 having a radial depth DT1E and the sidewall 240 having a radial depth DB1E. Depth D1E is equal to depth DT1E plus depth DB1E.

[0033] The inner portion of each outer section 234 may include a total radial depth D1I, with the chamfer-forming edge 238 having a radial depth DT1I and the sidewall 240 having a radial depth DB1I. Depth D1I is equal to depth DT1I plus depth DB1I.

[0034] In one aspect, radial depth DB1E is less than radial depth DB1I. In one aspect, radial depth DT1E is equal to radial depth DT1I. In another aspect, radial depths DT1E, DT1I, and DT2 are all equal to one another.

[0035] The central section 232 may include a total radial depth D2, with the key-forming edge 236 having a radial depth DT2 and the sidewall 244 having a radial depth DB2. Depth D2 is equal to depth DT2 plus depth DB2.

[0036] In one embodiment, radial depth DB2 is deeper than radial depth DB1E. In another embodiment, depth DB2 is equal to depth DB1I. In another embodiment, depth D2 is equal to depth D1I. In another embodiment, depth DT2 is equal to depth DT1I.

[0037] The central section 232 may include a length L2 (eg, axially).

[0038] The key-forming edge 236 includes an angle A1 relative to the axial direction. In one embodiment, the angle A1 is between about 45 degrees and about 75 degrees. In another embodiment, the angle A1 is between 45 degrees and 75 degrees. In another embodiment, the angle A1 is between about 50 degrees and about 70 degrees. In another embodiment, the angle A1 is between 50 degrees and 70 degrees. In another embodiment, the angle A1 is between about 55 degrees and about 65 degrees. In another embodiment, the angle A1 is between 55 degrees and 65 degrees. In another embodiment, the angle A1 is about 60 degrees. In another embodiment, the angle A1 is 60 degrees.

[0039] Chamfer-forming edge 238 includes an angle A2 relative to the axial direction. In one embodiment, angle A2 is between about 45 degrees and about 75 degrees. In another embodiment, angle A2 is between 45 degrees and 75 degrees. In another embodiment, angle A2 is between about 50 degrees and about 70 degrees. In another embodiment, angle A2 is between 50 degrees and 70 degrees. In another embodiment, angle A2 is between about 55 degrees and about 65 degrees. In another embodiment, angle A2 is between 55 degrees and 65 degrees. In another embodiment, angle A2 is about 60 degrees. In another embodiment, angle A2 is 60 degrees.

[0040] Angle A1 may be equal to angle A2, each relative to axial direction A, but one is a positive angle and the other is a negative angle.

[0041] The terms "includes" or "including," to the extent that they are used in this specification or in the claims, are intended to be inclusive, similar to the term "comprising," as interpreted when used as a transitional term in a claim. Furthermore, to the extent that 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 that the terms "in" or "into" are used in this specification or in the claims, they are 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.

[0042] As noted above, the present application has been illustrated by description 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 tire, a tread portion comprising at least one of a tread rib or a tread block; a sipe included in the tread rib or the tread block, the sipe includes a central section located between axially opposed outer sections, the central section and each outer section including a radially outer portion and a radially inner portion; the radially outer portion of each outer section has a circumferential width WT1; the radially outer portion of the center section has a circumferential width WT2; The circumferential width WT1 is larger than the circumferential width WT2, the radially inner portion of each outer section includes an axially outer portion having a radial depth DB1E and an axially inner portion having a radial depth DB1I; The tire, wherein the radial depth DB1E is smaller than the radial depth DB1I.

2. 10. The tire of claim 1, wherein the sipe center section has opposed key edges on its radially outer portion.

3. 2. The tire according to claim 1, wherein the width WT1 is 1.5 to 2.5 times the value of the width WT2.

4. The tire of claim 1 , wherein the radially inner portion of each outer section has a circumferential width WB1, said width WB1 being less than said width WT1.

5. The tire of claim 1 , wherein the radially inner portion of the center section has a circumferential width WB2, the width WB2 being greater than the width WT2.

Images