Claims
- 1. A tread for a tire, comprising a tread pattern formed by at least two grooves of generally circumferential orientation, these grooves delimiting at least two ridges (1) each comprising a contact face (2) intended to come in contact with the road and two lateral faces, these lateral faces intersecting the contact face to form edges (5, 6), at least one of said ridges, of mean width L, comprising a plurality of incisions (7) with maximum depth Hi which, in the new condition, open onto the contact face and onto the two lateral faces of the ridge, the trace of each incision on the contact surface extending between two points of intersection A and B with the edges of the ridge, the segment AB making an angle α with the transverse direction of the tread at most equal to 40°, said tread being characterized in that:
each incision (7) of mean width E, comprises, from one lateral face of the ridge to its other lateral face, a succession of incision portions (70, 71, 72, 73, 74), some of these incision portions, over at least a height He equal to half the maximum depth Hi of the incision and for any surface parallel to the contact surface in the new condition over said height He, having traces that make, with the longitudinal direction of the tread, an average angle α at most equal to 15°, said portions, viewed in projection on this longitudinal direction, having a total length Lt at least equal to one-fifth of the width L of the ridge; and in that the incision portions whose traces make an average angle α are provided on their opposite walls with relief elements of amplitude K designed to cooperate with one another, during passage through the road contact zone, to block the relative movements between one incision wall and the opposite wall in the direction of the thickness of the tread and in the longitudinal direction of the tread, the amplitude K of said relief elements being between 4 and 10 times the mean width E of the incision.
- 2. The tread for a tire according to claim 1, wherein the total length Lt, equal to the sum of the projections on the longitudinal direction Y of the lengths of the incision portions that make an angle at most equal to 15° with the longitudinal direction Y, is at least equal to one-third of the width L of the ridge.
- 3. The tread for a tire according to claim 1, wherein the walls delimiting the incision portions that make an angle β at most equal to 15° with the circumferential direction, comprise relief elements from the rolling surface down to a depth at least equal to 50% of the maximum depth Hi of the incision.
- 4. The tread for a tire according to claim 2, wherein the walls delimiting the incision portions that make an angle β at most equal to 15° with the circumferential direction, comprise relief elements from the rolling surface down to a depth at least equal to 50% of the maximum depth Hi of the incision.
- 5. The tread for a tire according to claim 1, wherein the average angle β is at most equal to 5°.
- 6. The tread for a tire according to claim 2, wherein the average angle β is at most equal to 5°.
- 7. The tread for a tire according to claim 1, wherein at least one portion of the incision is inclined relative to a plane perpendicular to the rolling surface, said plane passing through the point A, by an average angle different from 00.
- 8. The tread for a tire according to claim 2, wherein at least one portion of the incision is inclined relative to a plane perpendicular to the rolling surface, said plane passing through the point A, by an average angle different from 0°.
- 9. The tread for a tire according to claim 7, wherein the incisions are all inclined relative to a plane perpendicular to the rolling surface and passing through the point A, by a same average angle whose absolute value is at most equal to 15°, said incisions being inclined in alternation at a positive and at a negative angle.
- 10. The tread for a tire according to claim 1, wherein there are at least two incision portions with average inclination smaller than 15°, said portions having opposite inclinations.
- 11. The tread for a tire according to claim 1, wherein:
Priority Claims (1)
Number |
Date |
Country |
Kind |
01/09111 |
Jul 2001 |
FR |
|
Parent Case Info
[0001] The present application is a continuation of International Application Serial No. PCT/EP02/07003, filed Jun. 25, 2002, which is incorporated by reference.
Continuations (1)
|
Number |
Date |
Country |
Parent |
PCT/EP02/07003 |
Jun 2002 |
US |
Child |
10753418 |
Jan 2004 |
US |