TREAD FOR A PNEUMATIC TIRE

Abstract

A tread for a tire includes a first circumferential groove; a second circumferential groove; a third circumferential groove; and a fourth circumferential groove. The first, second, third, and fourth circumferential grooves define first, second, third, fourth, and fifth ribs. The second and fourth ribs include lateral grooves and lateral sipes, each extending in a first angled direction relative to the first circumferential groove across the tire tread. Two lateral sipes are disposed circumferentially between each adjacent pair of lateral grooves.

Claims

1. A tread for a tire comprising: a first circumferential groove extending in a circumferential direction of the tire; a second circumferential groove extending in the circumferential direction of the tire; a third circumferential groove extending in the circumferential direction of the tire; and a fourth circumferential groove extending in the circumferential direction of the tire, the first, second, third, and fourth circumferential grooves defining first, second, third, fourth, and fifth ribs, the second and fourth ribs including lateral grooves and lateral sipes, the lateral grooves and the lateral sipes each extending in a first angled direction relative to the first circumferential groove across the tire tread, two lateral sipes being disposed circumferentially between each pair of lateral grooves, one of the two lateral sipes extending in a first axial direction and having a first width transitioning in the first axial direction to a second wider width adjacent a lateral mid-point of the second and fourth ribs, the other of the two lateral sipes extending in a second axial direction and having a first width transitioning in the second axial direction to a second wider width adjacent a lateral mid-point of the second and fourth ribs, the first axial direction being opposite the second axial direction.

2. The tire tread as set forth in claim 1 wherein the third rib including lateral grooves and lateral sipes, the lateral grooves and the lateral sipes each extending in a second angled direction relative to the third circumferential groove across the tire tread, two lateral sipes being disposed circumferentially between each pair of lateral grooves, one of the two lateral sipes extending in the first axial direction and having a first width transitioning in the first axial direction to a second wider width adjacent a lateral mid-point of the third rib, the other of the two lateral sipes extending in the second axial direction and having a first width transitioning in the second axial direction to a second wider width adjacent a lateral mid-point of the third rib, the first angled direction being equal and opposite the second angled direction.

3. The tire tread as set forth in claim 1 wherein the first rib includes a secondary groove circumferentially extending completely around the first rib.

4. The tire tread as set forth in claim 3 wherein the first rib includes a tertiary groove circumferentially extending completely around the first rib.

5. The tire tread as set forth in claim 1 wherein the lateral grooves have a radial depth between 1.0 mm and 4.0 mm.

6. The tire tread as set forth in claim 1 wherein the lateral sipes have a radial depth between 1.0 mm and 3.0 mm.

7. The tire tread as set forth in claim 1 wherein the fifth rib includes one end blind sipes having a radial depth between 1.0 mm and 3.0 mm.

8. The tire tread as set forth in claim 1 wherein the first rib includes lateral grooves extending at a first angle relative to the first circumferential groove across the tread.

9. The tire tread as set forth in claim 8 wherein the first rib includes two sipes disposed circumferentially between each pair of lateral grooves, the two sipes extending at the first angle relative to the first circumferential groove across the tread.

10. The tire tread as set forth in claim 9 wherein the two sipes have a radial depth between 1.0 mm and 3.0 mm.

11. A tread for a tire comprising: a first circumferential groove extending in a circumferential direction of the tire; a second circumferential groove extending in the circumferential direction of the tire; a third circumferential groove extending in the circumferential direction of the tire; and a fourth circumferential groove extending in the circumferential direction of the tire, the first, second, third, and fourth circumferential grooves defining first, second, third, fourth, and fifth ribs, the second and fourth ribs including lateral grooves and lateral sipes, the lateral grooves and the lateral sipes each extending in a first angled direction relative to the first circumferential groove across the tire tread, two lateral sipes being disposed circumferentially between each pair of lateral grooves, one of the two lateral sipes extending in a first axial direction and having a first width transitioning in the first axial direction to a second wider width adjacent a lateral mid-point of the second and fourth ribs, the other of the two lateral sipes extending in a second axial direction and having a first width transitioning in the second axial direction to a second wider width adjacent a lateral mid-point of the second and fourth ribs, the first axial direction being opposite the second axial direction, the third rib including lateral grooves and lateral sipes, the lateral grooves and the lateral sipes each extending in a second angled direction relative to the third circumferential groove across the tire tread, two lateral sipes being disposed circumferentially between each pair of lateral grooves, one of the two lateral sipes extending in the first axial direction and having a first width transitioning in the first axial direction to a second wider width adjacent a lateral mid-point of the center rib, the other of the two lateral sipes extending in the second axial direction and having a first width transitioning in the second axial direction to a second wider width adjacent a lateral mid-point of the third rib, the first angled direction being equal and opposite the second angled direction.

12. The tire tread as set forth in claim 11 wherein the first rib includes a secondary groove circumferentially extending completely around the first rib.

13. The tire tread as set forth in claim 12 wherein the first rib includes a tertiary groove circumferentially extending completely around the first rib.

14. The tire tread as set forth in claim 13 wherein the lateral grooves have a radial depth between 1.0 mm and 4.0 mm.

15. The tire tread as set forth in claim 14 wherein the lateral sipes have a radial depth between 1.0 mm and 3.0 mm.

16. The tire tread as set forth in claim 15 wherein the fifth rib includes one end blind sipes having a radial depth between 1.0 mm and 3.0 mm.

17. The tire tread as set forth in claim 16 wherein the first rib includes lateral grooves extending at a first angle relative to the first circumferential groove across the tread.

18. The tire tread as set forth in claim 17 wherein the first rib includes two sipes disposed circumferentially between each pair of lateral grooves, the two sipes extending at the first angle relative to the first circumferential groove across the tread.

19. The tire tread as set forth in claim 18 wherein the two sipes have a radial depth between 1.0 mm and 3.0 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0098] The present invention will be more clearly understood by the following description of some examples thereof, with reference to the accompanying drawings, in which:

[0099] FIG. 1 is a schematic perspective view of an example tire in accordance with the present invention.

[0100] FIG. 2 is a schematic plan view of the tire illustrated in FIG. 1.

[0101] FIG. 3 is a schematic enlarged plan view of the tire illustrated in FIG. 1.

[0102] FIG. 4 is a schematic sectional view taken along line 4-4 in FIG. 3.

DESCRIPTION OF EXAMPLES OF THE PRESENT INVENTION

[0103] A tire 1 in accordance with the present invention may include a tread 100 with a first main circumferential groove 10, a second main circumferential groove 20, a third main circumferential groove 30, and a fourth main circumferential groove 40 all extending in a circumferential direction C of the tire forming the tread 100. Five land portions, or ribs 110, 120, 130, 140, 150 may be formed by these main circumferential grooves 10, 20, 30, 40. Each of the ribs 110, 120, 130, 140, 150 may have additional grooves and sipes extending laterally L and/or circumferentially C across the ribs 110, 120, 130, 140, 150 forming discreet and circumferentially repeating blocks, or tread elements 112, 122, 132, 142, 152. The main circumferential grooves 10, 20, 30, 40 may have, for example, a lateral width between 3.0 mm and 20.0 mm and an example radial depth between 5.0 mm and 13.0 mm. The tire 1 may be pneumatic or non-pneumatic.

[0104] The first shoulder rib 110 may have alternating lateral grooves 114 and one end blind sipes 116 extending axially and at a slight angle from the first main circumferential groove 10 axially toward the outer edge of the tread 100. The lateral grooves 114 may have a radial depth between 1.0 mm and 4.0 mm and the one end blind sipes 116 may have a radial depth between 1.0 mm and 3.0 mm. The bottom of the lateral grooves 114 may have humps or approximately 2.0 mm steps (not shown). The first shoulder rib 114 may further include a secondary groove 117 circumferentially extending completely around the tire 1. The secondary groove 117 may have a radial depth between 2.0 mm and 4.0 mm.

[0105] The second shoulder rib 150 may have alternating lateral grooves 154 and one end blind sipes 156 extending axially and at a slight angle from the fourth main circumferential groove 50 axially toward the outer edge of the tread 100. The lateral grooves 154 may have a radial depth between 1.0 mm and 4.0 mm and the one end blind sipes 156 may have a radial depth between 1.0 mm and 3.0 mm. The bottom of the lateral grooves 154 may have humps or approximately 2.0 mm steps (not shown). The second shoulder rib 154 may further include a secondary groove 157 circumferentially extending completely around the tire 1. The secondary groove 157 may have a radial depth between 2.0 mm and 4.0 mm. The second shoulder rib may also have a tertiary groove 159 circumferentially extending completely around the tire 1. The tertiary groove 159 may have a width less than a width of the secondary groove 157, such as 50% of the width of the secondary groove. The tertiary groove 159 may have a radial depth between 2.0 mm and 4.0 mm.

[0106] The three center main circumferential ribs 120, 130, 140 may have alternating angled grooves 124, 134, 144 and angled sipes 126, 136, 146 extending axially and circumferentially across the ribs 120, 130, 140 between the corresponding main circumferential grooves 10, 20, 30, 40. The lateral grooves 124, 134, 144 may have a radial depth between 1.0 mm and 4.0 mm and the one end blind sipes 126, 136, 146 may have a radial depth between 1.0 mm and 3.0 mm. As shown in FIGS. 2 and 3, the grooves 124, 144 and sipes 126, 146 of the outer ribs 120, 140 may extend at equal angles while the grooves 134 and sipes 136 of the center rib 130 may extend at an equal, but opposite, angle compared to the angle of the grooves 124, 144 and sipes 126, 146 of the outer ribs 120, 140.

[0107] The lateral grooves 124 of the first intermediate rib 120 may extend at a first angle 121 relative to the first circumferential groove 10 across the tire tread 100. Two of the lateral sipes 126 may be disposed circumferentially between each pair of lateral grooves 124. One of the two lateral sipes 126 may extend in a first axial direction and have a first width transitioning in the first axial direction to a second wider width adjacent a lateral mid-point of the first intermediate rib 120. The other of the two lateral sipes 126 may extend in a second axial direction and have a first width transitioning in the second axial direction to a second narrower width adjacent a lateral mid-point of the first intermediate rib 120. The first axial direction may be opposite the second axial direction (FIG. 3). The bottom of the angled sipes 126 may have humps or approximately 2.0 mm steps (not shown). The angled sipes 126 may have a radial depth between 1.0 mm and 4.0 mm.

[0108] The lateral grooves 134 of the center rib 130 may extend at a second angle 131 relative to the third circumferential groove 30 across the tire tread 100. Two of the lateral sipes 136 may be disposed circumferentially between each pair of lateral grooves 134. One of the two lateral sipes 136 may extend in a first axial direction and have a first width transitioning in the first axial direction to a second wider width adjacent a lateral mid-point of the center rib 130. The other of the two lateral sipes 136 may extend in a second axial direction and have a first width transitioning in the second axial direction to a second narrower width adjacent a lateral mid-point of the center rib 130. The first axial direction may be opposite the second axial direction (FIG. 3). The bottom of the angled sipes 136 may have humps or approximately 2.0 mm steps (not shown). The angled sipes 136 may have a radial depth between 1.0 mm and 4.0 mm.

[0109] The lateral grooves 144 of the second intermediate rib 140 may extend at a third angle 141 relative to the third circumferential groove 30 across the tire tread 100. Two of the lateral sipes 146 may be disposed circumferentially between each pair of lateral grooves 134. One of the two lateral sipes 146 may extend in a first axial direction and have a first width transitioning in the first axial direction to a second wider width adjacent a lateral mid-point of the second intermediate rib 140. The other of the two lateral sipes 146 may extend in a second axial direction and have a first width transitioning in the second axial direction to a second narrower width adjacent a lateral mid-point of the second intermediate rib 140. The first axial direction may be opposite the second axial direction (FIG. 3). The bottom of the angled sipes 146 may have humps or approximately 2.0 mm steps (not shown). The angled sipes 146 may have a radial depth between 1.0 mm and 4.0 mm.

[0110] As shown in FIG. 3, the first angle 121 may be equal to the third angle 141. The second angle 131 may be equal and opposite the first angle 121 and/or the third angle 141. The above described tire 1 and tread 100 may be utilized for all-season electric vehicles because of the tread's heavy load and high torque performance characteristics while maintaining acceptable rolling resistance and comfort performance. The design of the three middle ribs 120, 130, 140 may advantageously increase longitudinal stiffness of the tread 100 by as much as +10 percent. The asymmetric design may increase lateral grip by up to +3 percent. The shoulder sipes 116, 156 also increase lateral grip by as much as +5 percent. Sipe density and radial depth may be adjusted for optimum snow and dry handling performances. These factors result in a tread design that may improve snow, dry, and wet handling performances.

[0111] While the present invention has been described in connection with what is considered the most practical example, it is to be understood that the present invention is not to be limited to the disclosed arrangements, but is intended to cover various arrangements which are included within the spirit and scope of the broadest possible interpretation of the appended claims so as to encompass all possible modifications and equivalent arrangements.