Tire having tread with improved wear resistance
AssigneeMichelin Recherche et Technique S.A.
InventorTimothy A. White
Life of this patent
Estimating the term…
Abstract
A tread for a tire having a mid-circumferential plane. The tread comprises a plurality of tread elements arranged in a circumferential array about the tire. The tread also comprises a plurality of transverse extending grooves. Each of the grooves separate a pair of circumferentially adjacent tread elements. An area moment of inertia is associated with each of the tread elements when viewed normal to the tread element. Each of the area moments of inertia have a respective pair of principle axes of inertia relative to the mid-circumferential plane. The angular orientation between any pair of principle axes of inertia of different tread elements is within a predetermined angular range of 40 degrees or less.
Claims12
A tread when in an annular configuration for a tire, having a mid-circumferential plane, said tread comprising:
- a plurality of tread elements arranged in a circumferential array about the tire to form a shoulder rib, wherein respective tread elements have a non-zero pitch length variation;
- a plurality of transverse extending grooves, each of said grooves separating a pair of circumferentially adjacent tread elements and defining the circumferential pitch length for each of said plurality of tread elements;
- a single full depth sipe extending transversely across a tread element when the circumferential pitch length of said tread element is less than a predetermined circumferential pitch length;
- and
- at least a pair of full depth sipes extending transversely across a tread element when the circumferential pitch length of said tread element is greater than the predetermined circumferential pitch length, wherein the tread has both tread elements with the single sipe and tread elements with at least the pair of sipes;
- and
- an area moment of inertia associated with the sipe defined tread elements in the shoulder rib when viewed in a direction normal to the tread element, each of said area moments of inertia having orthogonal principle axes of inertia relative to the mid-circumferential plane, the angular orientation between any pair of respective principle axes of inertia of different sipe defined tread elements being within a predetermined angular range of 40 degrees or less and each of said area moments of inertia associated with each one of said principle axes having a magnitude, wherein the magnitude of a smallest moment of inertia is within 40 percent of a largest moment of inertia for the sipe defined tread elements in each shoulder rib circumferential array.
A tread when in an annular configuration for a tire, having a mid-circumferential plane, said tread comprising;
- a plurality of tread elements, including the tread elements of a shoulder rib and an intermediate rib, arranged in circumferential arrays about the tire, wherein respective tread elements in each rib have a non-zero pitch length variation;
- a plurality of transverse extending grooves, each of said grooves separating a pair of circumferentially adjacent tread elements and each adjacent pair being spaced apart a predetermined distance;
- a single full depth sipe extending across tread elements when the predetermined distance is less than a first predetermined value;
- at least two full depth sipes extending across a tread element when the predetermined distance is greater than the first predetermined value;
- an area moment of inertia associated with all sipe defined tread elements in the shoulder rib when viewed in a direction normal to the tread element, each of said area moments of inertia having orthogonal principle axes of inertia with an angular orientation of said axes relative to the mid-circumferential plane within a predetermined angular range, wherein the magnitude of a smallest moment of inertia is within forty (40) percent of a largest moment of inertia for the sipe defined tread elements;
- and
- a pair of full height contact pads on each one of the tread elements in the shoulder rib, wherein one contact pad is located on the leading edge and the other contact pad is located on the trailing edge of said each one of the tread elements.
Dependencies are inferred from the claim text.