US 12,459,301 B2
Heavy truck tire with shoulder rib sipe featuring bridging
Stefan Voss, Greer, SC (US)
Assigned to Compagnie Generale des Etablissements Michelin, Clermont-Ferrand (FR)
Appl. No. 17/758,041
Filed by COMPAGNIE GENERALE DES ETABLISSEMENTS MICHELIN, Clermont-Ferrand (FR); and Stefan Voss, Greer, SC (US)
PCT Filed Apr. 21, 2020, PCT No. PCT/US2020/029049
§ 371(c)(1), (2) Date Jun. 27, 2022,
PCT Pub. No. WO2021/216041, PCT Pub. Date Oct. 28, 2021.
Prior Publication US 2023/0084725 A1, Mar. 16, 2023
Int. Cl. B60C 11/12 (2006.01)
CPC B60C 11/1218 (2013.01) [B60C 11/124 (2013.01); B60C 11/1259 (2013.01); B60C 2011/1213 (2013.01); B60C 2200/06 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A heavy truck tire tread having a longitudinal direction, a lateral direction and a thickness direction, said tread comprising:
a shoulder edge;
a shoulder groove;
a shoulder rib defined between the shoulder edge and the shoulder groove, wherein the shoulder rib has an outer surface;
a plurality of sipes in the shoulder rib that extend from the shoulder edge to the shoulder groove, wherein each one of the sipes has a bottom with a teardrop located at the bottom, wherein the teardrop extends continuously along an entire lateral length of the sipe from the shoulder edge to the shoulder groove, wherein the bottom does not extend the same depth in the thickness direction across the entire lateral length of the sipe, wherein the bottom at a middle of the sipe extends for less of a depth in the thickness direction than does the bottom at a shoulder edge portion of the sipe located outboard from the middle of the sipe in the lateral direction, and wherein the bottom at the middle of the sipe extends for less of a depth in the thickness direction than does the bottom at a shoulder groove portion of the sipe located inboard from the middle of the sipe in the lateral direction;
wherein the teardrop is tapered upon extension from the shoulder groove towards the middle of the sipe such that the bottom extends for less of a depth in the thickness direction continuously from the shoulder groove to a first convex portion of the bottom at the middle of the sipe, wherein the bottom has a first concave portion that is located between the first convex portion and the shoulder groove;
wherein the bottom has a second convex portion at the middle of the sipe, and wherein the bottom has a second concave portion that is located between the second convex portion and the shoulder edge;
wherein the teardrop is circular in shape and has a diameter, wherein the diameter does not have the same magnitude along the entire lateral length of the sipe;
wherein the teardrop at the middle of the sipe has a straight segment that extends in the lateral direction but does not extend in the thickness direction, wherein the diameter of the teardrop at the straight segment is smaller than the diameter of the teardrop at a first tapered segment of the teardrop in the shoulder groove portion, and wherein the diameter of the teardrop at the straight segment is smaller than the diameter of the teardrop at a second tapered segment of the teardrop in the shoulder edge portion;
wherein the teardrop has a top that is a portion of the teardrop closest to the outer surface in the thickness direction, wherein the top has a first convex top portion that engages the first tapered segment, wherein the top extends continuously in both the thickness and lateral directions from the first convex top portion to the straight segment;
wherein the top has a second convex top portion that engages the second tapered segment, wherein the top extends continuously in both the thickness and lateral directions from the second convex top portion to the straight segment;
wherein an average sipe line is drawn from a point of the sipe 8 millimeters inboard in the lateral direction from the shoulder edge to a point of the sipe 8 millimeters outboard in the lateral direction from the shoulder groove;
wherein a reference plane lies in the longitudinal direction, wherein a sipe bottom point is located in the reference plane at the sipe bottom, wherein a sipe top point is located in the reference plane at the average sipe line, wherein a sipe inclination line extends from the sipe bottom point to the sipe top point, wherein a reference line extends in the thickness direction through the sipe bottom point and does not have a component in the longitudinal direction or the lateral direction, wherein the sipe inclination line is at a sipe inclination angle to the reference line, wherein the sipe inclination angle is greater than 0 degrees, wherein the sipe bottom point is configured to approach a contact patch before the sipe top point upon forward motion.