Tire tread for HGV trailer

Patent metadata

Field	Value
Publication number	US-11685193-B2
Application number	US-201816488512-A
Country	US
Kind code	B2
Filing date	Mar 2, 2018
Priority date	Mar 3, 2017
Publication date	Jun 27, 2023
Grant date	Jun 27, 2023

Abstract

Tire tread (1) is divided into central part (20) and edge parts (30), central part (20) having width Lc between 40% and 90% of total width W of the tread. Edge parts (30) do not have any transverse cuts. Central part (20) has a tread pattern with circumferentially oriented sipe (21) and transversely oriented sipes (22, 22′, 22″) distributed around the periphery of the tread, such sipes having a depth at least equal to 60% of thickness E of material to be worn away and being interconnected to form a network. Such sipes are continued by hidden channels (210, 220). Central part (20) is delimited axially by transverse sipes (22′, 22″), each of which ends in end channel (221′, 221″) that opens onto tread surface (10) and extends into the thickness of the tread, and each end channel (221′, 221″) is connected to the network formed by the hidden channels.

First claim

The invention claimed is:

1. Tread for a tire to equip a heavy-duty trailer, this tread having:
a thickness E of material in a new state to be worn away that determines a wear limit, a tread surface for coming into contact with a road surface, this tread being divided into:
a central part and
edge parts on either side of the central part, the edge parts not having any transverse cuts,
wherein the central part is provided with a tread pattern that does not have any circumferential grooves, this tread pattern comprising:
a plurality of sipes, comprising:
at least two circumferential sipes; and
transverse sipes, including a first set of lateral sipes arranged between the two circumferential sipes and a second set of lateral sipes each extending axially from a respective one of the two circumferential sipes towards a tread edge, each of these first and second sets of lateral sipes comprising a first end close to the mid-plane of the tread and a second end axially outside the first end, the second ends of the second set of lateral sipes axially delimiting a border between the edge parts and the central part of the tread, each lateral sipe opening at its first end into a circumferential sipe instead of a channel that opens onto the tread surface and continues into the thickness of the tread,
wherein the first set of lateral sipes and second set of lateral sipes are circumferentially offset from each other,
all the sipes of the central part of the tread extending in the tread to a depth at least equal to 60% of the thickness E of material to be worn away and being extended into the tread by circumferentially extending and axially extending hidden channels of appropriate dimensions for supplementing a continuous fluidic flow network under the tread surface in the new state, these hidden channels being adapted to form grooves after a predetermined amount of partial wear,
wherein the tread is entirely without grooves in its central part, this central part having a width at least equal to 40% and at most 90% of the total width W of the tread, and
wherein the second set of lateral sipes formed in the central part of the tread open at their second end into an end channel that opens onto the tread surface of the tread and continues into the thickness of said tread until it meets a hidden channel at the sipe bottom,
wherein the circumferential sipes, the lateral sipes and the hidden channels create a grid network forming the continuous fluidic flow network at a predetermined depth,
wherein each end channel that opens onto the tread surface of the tread is arranged at the border between the edge parts and the central part,
wherein each end channel, is at a respective axial outer end of the grid network and has only one of the second set of lateral sipes extending axially therefrom towards an axial center of the tread.

2. The tread according to claim 1 , wherein the central part has a width Lc that is at least equal to 80% of the total width W of the tread.

3. The tread according to claim 1 , wherein, the surface void ratio of the tread in the new state is at most equal to 7%.

4. The tread according to claim 1 , wherein the end channels have a cross-sectional area of between the cross-sectional area of a disc with a diameter equal to 15% of a width Lb of each edge part and the cross-sectional area of a disc with a diameter equal to 25% of the width Lb of each edge part.

5. The tread according to claim 4 , wherein the volumetric void ratio of the central part in the new state is chosen to be at least equal to 6% and at most equal to 9% and the surface void ratio is at least equal to 2% and at most equal to 6% in the new state.

6. The tread according to claim 1 , wherein the transverse sipes are inclined in the depth with respect to a radial direction at one and the same angle at most equal to 25 degrees.

7. The tread according to claim 1 , wherein the axially outermost transverse sipes of the central part of the tread are distributed around a wheel at a mean distance between two successive sipes of one and the same set at most equal to 2% of the perimeter of the tire measured on the equatorial mid-plane of said tire.

8. The tread according to claim 1 , wherein the end channels on one side of the central part are circumferentially offset from the end channels on the other side of the central part so that the end channels come into contact with the road surface at different times.

9. A tire provided with a tread according to claim 1 , wherein, this tire is adapted to be fitted to a load-bearing axle of a heavy-duty vehicle of the trailer type.

10. The tread according to claim 1 , wherein the transverse sipes are inclined in the depth with respect to a radial direction at one and the same angle between 0 degrees and 10 degrees.

11. The tread according to claim 1 , wherein the end channels are axially offset from circumferentially oriented grooves arranged in the edge parts.

12. The tread according to claim 1 , wherein each axially outer lateral sipe is provided with an end channel.

13. The tread according to claim 1 , wherein each end channel is arranged axially beyond each hidden channel and each of the first set of lateral sipes and the second set of lateral sipes.

14. A tread for a tire to equip a heavy-duty trailer, this tread having:
a thickness E of material in a new state to be worn away that determines a wear limit, a tread surface for coming into contact with a road surface, this tread being divided into:
a central part and
edge parts on either side of the central part, the edge parts not having any transverse cuts,
wherein the central part is provided with a tread pattern that does not have any circumferential grooves, this tread pattern comprising:
a plurality of sipes, comprising:
at least two circumferential sipes; and
transverse sipes, including a first set of lateral sipes arranged between the two circumferential sipes and a second set of lateral sipes each extending axially from a respective one of the two circumferential sipes towards a tread edge, each of these first and second sets of lateral sipes comprising a first end close to the mid-plane of the tread and a second end axially outside the first end, the second ends of the second set of lateral sipes axially delimiting a border between the edge parts and the central part of the tread, each lateral sipe opening at its first end into a circumferential sipe,
all the sipes of the central part of the tread extending in the tread to a depth at least equal to 60% of the thickness E of material to be worn away and being extended into the tread by circumferentially extending and axially extending hidden channels of appropriate dimensions for supplementing a continuous fluidic flow network under the tread surface in the new state, these hidden channels being adapted to form grooves after a predetermined amount of partial wear,
wherein the tread is entirely without grooves in its central part, this central part having a width at least equal to 40% and at most 90% of the total width W of the tread, and
wherein the second set of lateral sipes formed in the central part of the tread open at their second end into an end channel that opens onto the tread surface of the tread and continues into the thickness of said tread until it meets a hidden channel at the sipe bottom, and thus creates the continuous fluidic flow network between all the channels, regardless of whether they are lateral or hidden,

wherein each end channel that opens onto the tread surface of the tread is arranged at the border between the edge parts and the central part,
wherein the edge parts do not have any ci

Assignees

• Michelin & Cie

Inventors

• Dayet Patrick
• Buffetaud Benoit
• Babaud Jacques

Classifications

• B60C2011/1245

  being arranged in crossing relation, e.g. sipe mesh · CPC title

• B60C2011/1209

  straight at the tread surface · CPC title

• B60C11/1281 Primary

  different within the same sipe, i.e. enlarged width portion at sipe bottom or along its length · CPC title

• B60C11/0323 Primary

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

• B60C11/1259

  Depth of the sipe · CPC title