Tread for a Tire
AssigneeCompagnie Generale Des Etablissements Michelin
InventorsFrançois BARBARIN, Guillaume DEMAZIERE
Life of this patent
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Abstract
Tread (10) for a tire of an off-road vehicle. Total width Wt of the tread is greater than 600 mm and has at least three circumferential main grooves (1, 2, 3, 4) at least 60 mm deep that divide the tread into intermediate ribs (51, 52, 53) and edge ribs (8). The edge ribs have a width ≤0.25 Wt. At least one of the intermediate ribs (51, 52, 53) has fine grooves (61, 62, 63) of depth H1 delimiting blades of material (71, 72, 73) of mean width B1<2H1. Grooves (61, 62, 63) are oriented in the axial direction of the tire. Each intermediate rib (51, 52, 53) has a mean width ≤0.25 Wt and ≥0.75 Ht (thickness of material to be worn away). Grooves, (61, 62, 63) have, over a height H12 at least equal to 65% of H1, a width ≤ to the value obtained from 0.04√(B1·H1).
Claims11
A tread for a tire of an off-road vehicle carrying very heavy loads, the tread having a total width Wt greater than 600 mm and a thickness Ht of material to be worn away, the tread having at least three main grooves of circumferential overall orientation and with a depth at least equal to 60 mm, said main grooves dividing the tread into intermediate ribs and edge ribs, the edge ribs axially bounding the tread and having a width at most equal to one quarter of the total width Wt of the tread, at least one of the intermediate ribs having a plurality of fine grooves;
- each said fine groove opens into a main groove and has a depth H1, said fine grooves, with the main grooves, delimiting blades of material of mean width B1 less than twice the depth H1, said fine grooves being oriented in the transverse direction corresponding to the axial direction of the tire or in an oblique direction, namely with an orientation that makes an angle at most equal to 45 degrees with the transverse or axial direction of the tire, wherein each said intermediate rib has a mean width at most equal to one quarter of the total width Wt of the tread and at least equal to 0.75 times the thickness Ht of material to be worn away, and wherein the fine grooves have, over a height H12 at least equal to 65% of their total depth H1, a width which is at most equal to the value obtained from the following mathematical expression:
- 0.04√{square root over (B1·H1)}.
Dependencies are inferred from the claim text.