Tire tread for a heavy vehicle with an improved resistance to stresses
AssigneeCompagnie Generale Des Etablissements Michelin
InventorXavier Neau
Life of this patent
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Abstract
A tread for a tire for a heavy-duty vehicle for mixed use and aims to improve the endurance of the crown of the tire following retention of stones in the tread. The tread (1) has voids (3) with a first, radially outer void portion (31) of groove type, having a width W11 on the tread surface (2), a width W12 at a groove bottom (311), and a depth H1, and a second, radially inner void portion (32) of sipe type, having a width W2 and a depth H2 and leading into the groove bottom (311) at a distance E with respect to the mean surface (S1) of the groove (31). The distance E is at least equal to the width W12 of the groove bottom (311) divided by 6.
Claims8
A tread for a tire for a heavy-duty vehicle, which tread is intended to come into contact with ground via a tread surface and comprises voids that are delimited by elements in relief with respect to a bottom surface and extend over a specific length,
- at least one void having a depth H and comprising, over at least some of its length, a first, radially outer void portion leading into the tread surface, and a single second, radially inner void portion leading into the first void portion,
- the first void portion being a groove having a trapezoidal cross section and having a width W11, measured on the tread surface perpendicularly to a mean surface (S1) of the groove, and having a depth H1, measured perpendicularly from the tread surface to a groove bottom, which is planar, having a width W12,
- the single second void portion being a sipe having a width W2, measured perpendicularly to a mean surface of the sipe, and having a depth H2, measured perpendicularly from the groove bottom to a sipe bottom, the sipe bottom having a rounded contour having a radius R equal to 1.5 times the width W2 of the sipe,
- the depth H1 of the groove being at least equal to 0.5 times the depth H2 of the sipe and at most equal to twice the depth H2 of the sipe and the depth of the void H is equal to a sum of the depth of the first void portion H1 and the depth of the single second void portion H2,
- the sipe leading into the groove bottom at a distance E, measured between the mean surface (S1) of the groove and the mean surface (S2) of the sipe,
- wherein the distance E at which the sipe leads into the groove bottom is at least equal to the width W12 of the groove bottom divided by 6,
- wherein the mean surface (S1) of the groove forms an angle at most equal to 45° with the transverse direction (YY′),
- wherein the trapezoidal cross section of the first void portion comprises side walls between the tread surface and the groove bottom that taper radially inward towards one another at opposite acute angles with respect to the mean surface (S1) of the groove.
Dependencies are inferred from the claim text.