Patent Application
20240408918
Tires for use on vehicles may comprise a tread featuring sipes. The presence of sipes in a tire tread may create more surface edges to engage a roadway, which may increase traction in adverse road conditions. For example, a tire tread including sipes may perform better in icy, snowy, or wet road conditions than a tire tread not including sipes. Likewise, the more sipes a tire has, the better traction it may exhibit in adverse road conditions.
However, the addition of sipes to a tire tread block may reduce block stiffness, which may result in undesirable irregular wear patterns in the tire and a decrease in tire performance in dry road conditions (i.e., non-adverse conditions). Increasing the number of sipes in a tire tread block may relate to a decrease in stiffness of that tire tread block.
It may be desirable to form sipes with an interlocking shape to regain at least some of the stiffness lost in the tread block from increasing the number of sipes. It may be desirable to make the interlocking sipes as thin as possible in their interlocking region. This configuration may improve braking performance on dry surfaces. Additionally, for tires with deep tread depth, sipes must be deeper (and thus sipe blades taller) to effect the desired performance enhancements. It may therefor be desirable to make sipe blade configured to form a sipe as thin and/or as tall as possible while maintaining a durability of the sipe blade within a tire mold.
What is needed is an interlocking tire sipe configured to provide adequate block stiffness and/or braking performance, while allowing the sipe blade to be as thin and/or tall as needed while maintaining the durability of the sipe blade within a tire mold.
In one aspect, a tire having a sipe is provided, the tire comprising: wherein the sipe is a three-dimensional sipe extending radially inwardly into the tire from a tread surface of the tire, wherein the sipe includes a horizontal undulating portion having at least one horizontal midpoint portion and at least one horizontal peak portion, wherein the sipe includes a radial undulating portion having a vertical amplitude VA1 in the at least one horizontal midpoint portion and a vertical amplitude VA2 in the at least one horizontal peak portion, and wherein the vertical amplitude VA1 is greater than the vertical amplitude VA2.
In another aspect, a tire having a sipe is provided, the tire comprising: wherein the sipe is a three-dimensional sipe extending radially inwardly into the tire from a tread surface of the tire, wherein the sipe includes a horizontal undulating portion having at least one horizontal midpoint portion and at least one horizontal peak portion, wherein the sipe includes a radial undulating portion having a vertical amplitude VA1 in the at least one horizontal midpoint portion and a vertical amplitude VA2 in the at least one horizontal peak portion, wherein the vertical amplitude VA1 is greater than the vertical amplitude VA2, wherein the value of the vertical amplitude VA1 is between the value of the vertical amplitude VA2 and 1.50 mm, and wherein the value of the vertical amplitude VA2 is between 0.00 mm and the value of the vertical amplitude VA1.
The accompanying figures, which are incorporated in and constitute a part of the specification, illustrate various example configurations, and are used merely to illustrate various example embodiments. In the figures, like elements bear like reference numerals.
Tires not intended for operation on smooth, dry surfaces typically comprise a tread pattern, including a least one groove, at least one rib, and/or a plurality of tread blocks. Tires intended for operation in inclement conditions, including for example icy or snowy conditions, may additionally comprise a plurality of sipes in the tire tread. The addition of sipes in the tire tread may result in more surface edges in the tire tread for engagement with the icy or snowy roadway.
Increasing the length of a sipe, such as providing the sipe with a three-dimensional pattern, may increase the amount and length of cutting edges available to engage snowy, icy, and/or wet road surfaces.
Providing the sipe with a three-dimensional pattern in at least one of the lateral direction of the tire and the radial direction of the tire, may allow opposing walls of the sipe to at least partially engage one another in a high friction, or locking, manner to maintain a desired stiffness of the tire tread block or tire tread rib. Maintaining a specified level of stiffness in the tire tread may mitigate or eliminate irregular wear patterns. Maintaining a specified level of stiffness in the tire tread may improve stopping distance of the tire. Maintaining a specified level of stiffness in the tire tread may improve traction of the tire.
Providing interlocking three-dimensional sipes that are as thin as possible in their interlocking regions may be advantageous. Thus, sipe thicknesses (and thus sipe blade thicknesses) of 0.3 mm or less may provide advantageous results. Further, sipe thicknesses (and thus sipe blade thicknesses) below 0.3 mm may be more advantageous.
However, sipe blades used to form sipes having the desired traction while maintaining the desired block stiffness are often made as thin as possible, which may lead to sipe blade durability issues.
For consistency, the X-axis is oriented in the circumferential direction of the tire, the Y-axis is oriented in the axial direction of the tire, and the Z-axis is oriented in the radial direction of the tire.
Horizontal undulating portion 124 may form, at tread surface 102, a wave, which may be a sinusoidal wave. Horizontal undulating portion 124 may instead be linear elements angled relative to one another and connected by curves/filets. Horizontal undulating portion 124 of sipe 120 includes horizontal peak portions 128 and horizontal midpoint portions 130. A sectional view of sipe 120 at horizontal midpoint portion 130 (taken about section A-A) is illustrated in
Horizontal undulating portion 124 may have a surface thickness TS. Surface thickness TS may range between the value of the internal thickness TI (see
At least a portion of horizontal non-undulating portions 126 may intersect groove 112, 114, 116 and wherein horizontal non-undulating portions 126 may include a sipe thickness equal to surface thickness TS, throughout the radial depth of sipe 120. Terminal ends 122 may include a sipe thickness equal to surface thickness TS, throughout the radial depth of sipe 120.
Horizontal undulating portion 124 may have a horizontal period HP. Horizontal period HP may be between 4.50 mm and 15.00 mm. Horizontal period HP may be 7.50 mm, 6.64 mm, or 10.40 mm.
Horizontal undulating portion 124 may have a horizontal amplitude HA. Horizontal amplitude HA is measured from the centerline of sipe 120 at horizontal peak portions 128. Horizontal amplitude HA may be between 1.50 mm and 3.50 mm. Horizontal amplitude HA may be 2.40 mm or 2.11 mm.
Horizontal undulating portion 124 may have a horizontal angle A1 measured between a centerline of sipe 120 (e.g., a line parallel to and extending longitudinally down the middle of horizontal non-undulating portions 126) and the centerline of a horizontal midpoint portion 130. Horizontal angle A1 may be between 35 degrees and 55 degrees. Horizontal angle A1 may be 45 degrees.
Internal thickness TI may be between 0.05 mm and surface thickness TS. Internal thickness TI may be between 0.05 mm and 1.50 mm. Internal thickness TI may be 0.15 mm or 0.30 mm.
Base thickness TB may range between the value of the internal thickness TI and 1.50 mm. Base thickness TB may be between 0.05 mm and 1.50 mm. Base thickness TB may be 0.60 mm. Base thickness TB may be equal to surface thickness TS.
Radial undulating portion 136 may form a wave, which may be a sinusoidal wave. Radial undulating portion 136 may instead be linear elements angled relative to one another and connected by curves/filets.
The overall depth D of sipe 120 may be between 4.50 mm and 20.00 mm. Depth D may be 6.30 mm, 6.80 mm, 6.70 mm, or 11.18 mm.
The first radially inward peak of radial undulating portion 136 may have a depth P1 from tread surface 102 of between about 1.20 mm and 2.40 mm. Depth P1 may be 1.70 mm.
Radial undulating portion 136 may include a vertical period VP. Vertical period VP may be between 1.60 mm and 3.50 mm. Vertical period VP may be 2.30 mm or 2.50 mm.
Referring specifically to
Sipe 120 at a horizontal midpoint portion 130, may include a radial undulating portion 136 with a radius R1. Radius R1 may be between 0.15 mm and 1.50 mm. Radius R1 may be 0.15 mm.
Radial undulating portion 136 may have a radial angle RA1 measured between a sipe 120 (e.g., a line parallel the radial, Z-axis) and the centerline of a sipe 120. Radial angle RA1 may be between radial angle RA2 and 45 degrees. Radial angle RA1 may be 41 degrees.
Referring specifically to
Sipe 120 at a horizontal peak portion 128, may include a radial undulating portion 136 with a radius R2. Radius R2 is greater than radius R1. Radius R2 may be 0.63 mm or 4.45 mm.
Radial undulating portion 136 may have a radial angle RA2 measured between a sipe 120 (e.g., a line parallel the radial, Z-axis) and the centerline of a sipe 120. Radial angle RA2 may be between 0 degrees and angle RA1. Radial angle RA2 may be 13 degrees or 4 degrees.
Between horizontal midpoint portion 130 and horizontal peak portion 128, sipe 120 has a smooth, blended transition between the two sipe profiles illustrated in
Radial undulating portion 236 may include one or more full period portion 240 and/or one or more half period portion 242. Radial undulating portion 236 may include between 1.0 and 8.0 periods. Radial undulating portion 236 may include 1.5 periods, 2.5 periods, or 3.5 periods.
The varying amplitude (VA1 and VA2) as described herein may act to improve the strength of a sipe blade used to make sipes 120, 220, while allowing the thickness of the sipe blade (and sipes 120, 220) to be minimized without concerns regarding blade durability. Sipe blades used to make sipe 120, 220 may be able to be made radially “taller,” for deeper overall depths D without concerns regarding blade durability. Sipes 120, 220 may exhibit improvement in dry braking (2.5% improvement versus prior art sipes) and improvement in wet performance (2.0% improvement versus prior art sipes).
To the extent that the term “includes” or “including” is used in the specification or the claims, it is intended to be inclusive in a manner similar to the term “comprising” as that term is interpreted when employed as a transitional word in a claim. Furthermore, to the extent that the term “or” is employed (e.g., A or B) it is intended to mean “A or B or both.” When the applicants intend to indicate “only A or B but not both” then the term “only A or B but not both” will be employed. Thus, use of the term “or” herein is the inclusive, and not the exclusive use. 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 the specification or the claims, it is intended to additionally mean “on” or “onto.” To the extent that the term “substantially” is used in the specification or the claims, it is intended to take into consideration the degree of precision available or prudent in manufacturing. To the extent that the term “selectively” is used in the specification or the claims, it is intended to refer to a condition of a component wherein a user of the apparatus may activate or deactivate the feature or function of the component as is necessary or desired in use of the apparatus. To the extent that the term “operatively connected” is used in the specification or the claims, it is intended to mean that the identified components are connected in a way to perform a designated function. As used in the specification and the claims, the singular forms “a,” “an,” and “the” include the plural. Finally, where the term “about” is used in conjunction with a number, it is intended to include ±10% of the number. In other words, “about 10” may mean from 9 to 11. Cartesian coordinates referenced herein are intended to comply with the SAE tire coordinate system.
As stated above, while the present application has been illustrated by the description of aspects thereof, and while the 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 detail. Additional advantages and modifications will readily appear to those skilled in the art, having the benefit of the present application. Therefore, the application, in its broader aspects, is not limited to the specific details, illustrative examples shown, or any apparatus referred to. Departures may be made from such details, examples, and apparatuses without departing from the spirit or scope of the general inventive concept.
This application claims priority from U.S. Provisional Patent Application No. 63/251,443 filed on Oct. 1, 2021, which is incorporated by reference herein in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/077052 | 9/27/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63251443 | Oct 2021 | US |
