Heavy goods vehicle driven axle tire tread

Patent metadata

Field	Value
Publication number	US-9764598-B2
Application number	US-201314390403-A
Country	US
Kind code	B2
Filing date	Apr 5, 2013
Priority date	Apr 5, 2012
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

Tread having a maximum thickness PMU of material to be worn away during running, having: at least two grooves of circumferential overall orientation delimiting at least one intermediate row and two edge rows, a plurality of cuts of transverse overall orientation on each intermediate and edge row, representing, in the new state, a void of total volume Vco open onto the tread surface, at most equal to 13% of the total volume of the tread, channels or cavities extending under the tread surface in the new state, adapted to form new grooves after the tread has partially worn away, and having, in the initial state, a total volume Vcc at least equal to 30% of the total void volume Vco in the new state, intermediate rows of suffix (i) and edge rows of suffix (e) each provided with a plurality of cuts of transverse or oblique orientation distributed over each row evenly or near-evenly with a mean pitch of Pi and Pe respectively, having mean depths, Di and De respectively, which are at least equal to 20% of the thickness PMU and at most equal to thickness PMU, wherein:
on the edge rows, Pe is such that 1.30<Pe/De<3.00, and on the intermediate rows, Pi satisfies 1.00<Pi/Di<1.70, and Pe is greater than Pi.

First claim

The invention claimed is:

1. A tread for a tire, having a tread surface adapted to come into contact with a roadway, the tread having a width W and a total thickness E, the total thickness E corresponding to the total thickness of material measured on the equatorial plane between the tread surface when the tire is in the initial or new state and the radially outermost part of a crown reinforcement, the tread having a maximum thickness PMU of material to be worn away during running, the maximum thickness PMU being less than the total thickness E, comprising:
at least two grooves of circumferential overall orientation delimiting at least one intermediate row of suffix (i) and two edge rows of suffix (e), these edge rows axially delimiting the tread in the width W thereof,
a plurality of cuts of transverse overall orientation which are formed on each of the intermediate and edge rows, all of the grooves of circumferential overall orientation and cuts of transverse overall orientation representing, in the new state, a void of total volume Vco open onto the tread surface (open-voids volume), the volume Vco being at most equal to 16% of the total volume Vt of the tread, the total volume Vt being equal to the sum of the volumes of material to be worn away and of all the voids,
channels or cavities under the tread surface when the tread is in the new state, these channels forming a hidden void of total volume Vcc and being adapted to form new grooves after the tread has partially worn away, this hidden void having, in the initial state, a total volume Vcc at least equal to 30% of the total void volume Vco opening onto the tread surface in the new state,
wherein the at least one intermediate row of suffix (i) and the at least one edge row of suffix (e) are each provided with a plurality of cuts of transverse or oblique orientation distributed over each row evenly or near-evenly with a mean pitch of respectively Pi in the case of the intermediate rows and Pe in the case of the edge rows, these cuts having mean depths, Di and De respectively, which are at least equal to 20% of the thickness PMU and at most equal to this same thickness PMU,

wherein:
on the edge rows, the mean pitch Pe of the cuts is determined so that the relationship 1.30<Pe/De<3.00 is satisfied, and
on the intermediate rows, the mean pitch Pi of the cuts satisfies the relationship 1.00<Pi/Di<1.70, and
the mean pitch Pe of the cuts on the edge rows is greater than the pitch Pi on the intermediate rows.

2. The tread according to claim 1 , wherein the pitch Pe of the cuts on the edge rows and the pitch Pi on the intermediate rows satisfy the relationship: 1.25<Pe/Pi<1.80.

3. The tread according to claim 1 , wherein the open-voids volume Vco in the new state is at most equal to 13% of the total volume Vt of the tread.

4. The tread according to claim 1 , wherein the open-voids volume Vco in the new state is at most equal to 10% of the total volume Vt of the tread.

5. The tread according to claim 1 , wherein first hidden voids open onto the tread surface following partial wear representing at least 20% of the thickness PMU and at most 70% of that same thickness.

6. The tread according to claim 1 , wherein the total thickness to be worn away PMU, which thickness includes any part associated with potential regrooving, is at most equal to 23 mm.

7. The tread according to claim 1 , wherein a plurality of channels extend into the thickness of the tread down to a depth greater than the maximum thickness of material to be worn away PMU and at most down to the total thickness E.

8. A heavy goods vehicle tire, this tire comprising a carcass reinforcement surmounted by a crown reinforcement, this crown reinforcement extending on either side of an equatorial plane that divides the tire into two equal or substantially equal parts, this tire comprising, radially on the outside of the crown reinforcement, a tread according to claim 1 , this tire being mountable on a driven axle of a heavy goods vehicle.

Assignees

• Michelin & Cie
• Michelin Rech Tech
• Michelin & Cie

Inventors

• Radulescu Robert Ciprian
• Marlier Fabien
• Quantinet Benjamin
• Rolland Maxime

Classifications

• B60C11/12

  characterised by the use of narrow slits or incisions, e.g. sipes · CPC title

• B60C11/033

  by the void or net-to-gross ratios of the patterns · CPC title

• B60C2011/0033

  Thickness of the tread · CPC title

• B60C11/0323 Primary

  tread comprising channels under the tread surface, e.g. for draining water · CPC title

• B60C11/1218

  Three-dimensional shape with regard to depth and extending direction · CPC title