Tire for heavy vehicles

Patent metadata

Field	Value
Publication number	US-9499011-B2
Application number	US-32620506-A
Country	US
Kind code	B2
Filing date	Jan 5, 2006
Priority date	Jul 18, 2003
Publication date	Nov 22, 2016
Grant date	Nov 22, 2016

Abstract

The invention relates to a tire, the aspect ratio H/S of which is strictly greater than 0.55, having a radial carcass reinforcement comprising a crown reinforcement formed of at least two working crown layers of inextensible reinforcement elements, crossed from one ply to the other forming angles of between 10° and 45° with the circumferential direction, which itself is topped radially by a tread, said tread being joined to two beads by means of two sidewalls and the crown reinforcement comprising at least one layer of circumferential reinforcement elements.
According to the invention, the ratio of the thickness of the crown block at one shoulder end to the thickness of the crown block in the circumferential median plane is less than 1.20 and the ratio of the axial width of at least one layer of circumferential reinforcement elements to the axial width of the tread is greater than 0.5 and preferably greater than 0.6.

First claim

The invention claimed is:

1. A tire configured for at least one of a truck and a bus having an aspect ratio H/S strictly greater than 0.55 and less than 0.75, said tire having a radial carcass reinforcement comprising a crown reinforcement formed of at least two working crown layers of inextensible reinforcement elements, crossed from one ply to another forming angles of between 10 and 45 with a circumferential direction, said crown reinforcement being topped radially by a tread, said tread being joined to two beads by means of two sidewalls, the crown reinforcement comprising at least one layer of circumferential reinforcement elements,
wherein the ratio of a thickness of a crown block at one shoulder end to a thickness of the crown block in a circumferential median plane is less than 1.20 and greater than 1;
wherein the thickness of a crown block at one shoulder end is defined by a length of an orthogonal projection of the shoulder end on a radially innermost layer of rubber mix of the tire from the shoulder end on the outer surface of the tire to the radially innermost layer of rubber mix; and
wherein the shoulder end is defined, in a zone of the shoulder of the tire, by the orthogonal projection orthogonal to an outer surface of the tire of an intersection of tangents to surfaces of an axially outer end of the tread and of a radially outer end of a sidewall,
wherein the ratio of the axial width of the at least one layer of circumferential reinforcement elements to the axial width of the tread is greater than 0.65,
wherein a ratio of the axial width of the tread to a maximum axial width of the tire is greater than or equal to 0.80.

2. The tire according to claim 1 , wherein the ratio of the thickness of the crown block at one shoulder end to the thickness of the crown block in the circumferential median plane is less than 1.15.

3. The tire according to claim 1 , wherein the at least one layer of circumferential reinforcement elements is continuous over its entire axial width.

4. The tire according to claim 1 , wherein an axially widest working crown layer is radially to an inside of at least one of the at least two working crown layers.

5. The tire according to claim 1 , wherein a difference between an axial width of an axially widest working crown layer of the at least two working crown layers and an axial width of an axially least wide working crown layer of the at least two working crown layers is between 10 and 30 mm.

6. The tire according to claim 1 , wherein a distance between an end of an axially widest working crown layer of the at least two working crown layers and the carcass reinforcement is between 2 and 15 mm.

7. The tire according to claim 1 , wherein the axial width of the at least one layer of circumferential reinforcement elements is less than an axial width of an axially widest working crown layer of the at least two working crown layers.

8. The tire according to claim 1 , wherein the at least one layer of circumferential reinforcement elements is arranged radially between the at least two working crown layers.

9. The tire according to claim 8 , wherein axial widths of the working crown layers radially adjacent to the layer of circumferential reinforcement elements are greater than an axial width of said layer of circumferential reinforcement elements.

10. The tire according to claim 9 , wherein the working crown layers adjacent to the layer of circumferential reinforcement elements, on either side of an equatorial plane and in an immediate axial extension of the layer of circumferential reinforcement elements, are coupled over an axial width, then being decoupled by profiled elements of rubber mix at least over the remainder of a width common to said two working crown layers.

11. The tire according to claim 1 , wherein the reinforcement elements of the at least one layer of circumferential reinforcement elements are metallic reinforcement elements having a secant modulus at 0.7% elongation of between 10 and 120 GPa and a maximum tangent modulus of less than 150 GPa.

12. The tire according to claim 11 , wherein the secant modulus of the reinforcement elements at 0.7% elongation is less than 100 GPa.

13. The tire according to claim 12 , wherein the secant modulus of the reinforcement elements at 0.7% elongation is greater than 20 GPa.

14. The tire according to claim 12 , wherein the secant modulus of the reinforcement elements at 0.7% elongation is between 30 and 90 GPa.

15. The tire according to claim 11 , wherein a maximum tangent modulus of the reinforcement elements is less than 130 GPa.

16. The tire according to claim 15 , wherein a maximum tangent modulus of the reinforcement elements is less than 120 GPa.

17. The tire according to claim 1 , wherein the reinforcement elements of said layer of circumferential reinforcement elements are metallic reinforcement elements having a curve of tensile stress as a function of a relative elongation having shallow gradients for low elongations and a substantially constant, steep gradient for the higher elongations.

18. The tire according to claim 1 , wherein the reinforcement elements of the at least one layer of circumferential reinforcement elements are metallic reinforcement elements cut so as to form sections of a length less than a circumference of a least long ply, but greater than 0.1 times said circumference, the cuts between sections being axially offset from each other.

19. The tire according to claim 18 , wherein a modulus of elasticity in tension per unit of a width of the at least one layer of circumferential reinforcement elements is less than a modulus of elasticity in tension, measured under the same conditions, of the most extensible working crown layer.

20. The tire according to claim 1 , wherein the reinforcement elements of the at least one layer of circumferential reinforcement elements are undulating metallic reinforcement elements, a ratio a/λ of an amplitude of undulation a to a wavelength λ being at most equal to 0.09.

21. The tire according to claim 20 , wherein a modulus of elasticity in tension per unit of width of the at least one layer of circumferential reinforcement elements is less than a modulus of elasticity in tension, measured under the same conditions, of the most extensible working crown layer.

22. The tire according to claim 1 , wherein an angle formed with the circumferential direction by the reinforcement elements of the working crown layers is less than 30°.

23. The tire according to claim 1 , wherein the working crown layers comprise reinforcement elements, crossed from one ply to the other, forming with the circumferential direction angles which are variable in an axial direction.

24. The tire according to claim 1 , wherein the crown reinforcement is finished off radially to an outside by at least one supplementary layer of elastic reinforcement elements, which are oriented relative to the circumferential direction at an angle of between 10° and 45° and of the same direction as an angle formed by the inextensible elements of an adjacent one of the working crown layers.

25. The tire according to claim 1 , wherein the crown reinforcement furthermore comprises a triangulation layer formed of metallic reinforcement elements forming angles greater than 60° with the circumferential direction.

26. The tire according to claim 1 , wherein the ratio of a thickness of the crown block at one shoulder end to a thic

Assignees

• Radulescu Robert
• Cluzel Guy
• Michelin Rech Tech

Inventors

• Radulescu Robert
• Cluzel Guy

Classifications

• B60C2200/06

  for heavy duty vehicles · CPC title

• B60C9/28

  characterised by the belt or breaker dimensions or curvature relative to carcass (B60C9/30 takes precedence) · CPC title

• B60C2011/0033

  Thickness of the tread · CPC title

• B60C9/2006

  consisting of steel cord plies only · CPC title

• B60C11/01 Primary

  Shape of the shoulders between tread and sidewall, e.g. rounded, stepped or cantilevered · CPC title