Optimized architecture of civil engineering pneumatics

Abstract

A tire (1) for a mining construction vehicle comprising two protective layers (31) including elastic metallic reinforcements having a modulus of extension of at least 40 GPa and at most 140 GPa, and two working layers. The breaking strength FR of the metallic reinforcements of the outermost radially protective layer (311) is at least 3,000 N, their pitch being greater than 0.70*FR / 1000. The metallic reinforcements of the outermost radially protective layer (311) form, with a circumferential direction (XX') tangent to the circumference of the tire, an angle APN whose absolute value is at least 35°. (Shorthand figure: Figure 1)

Claims

Demands

1. A tire (1) for mining construction vehicles, intended to be mounted on a rim having a diameter at site of at least 25 inches, comprising: - a crown reinforcement (3), radially internal to a tread (2), having a tread height of at least 30 mm, and radially external to a carcass reinforcement (4) and comprising crown layers (311, 312, 321, 322, 331, 332) comprising metallic reinforcements, - the crown reinforcement (3) comprising two protective layers (311, 312), the outermost radial layers of the crown layers, said protective layers comprising elastic metallic reinforcements having an extension modulus of at least 40 GPa and at most 140 GPa, embedded in a rubber compound, called a calendering compound, parallel to each other, and having a breaking strength FR, - the top reinforcement comprising at least two working layers (321, 322), each working layer (321,322) being radially internal to the protective layers (311, 312) and comprising metallic reinforcements, parallel to each other and forming, with the circumferential direction (XX') tangent to the circumference of the tire, an angle whose absolute value is at least equal to 17°, - characterized in that the breaking strength FR of the metallic reinforcements of the outermost radially external protective layer (311) is at least equal to 2500 N, in that the pitch of the metallic reinforcements of the outermost radially external protective layer (311) is greater than FR / 1000 and in that the metallic reinforcements of the outermost radially external protective layer (311) form, with a circumferential direction (XX') tangent to the circumference of the tire, an angle APN whose absolute value is at least equal to 40°.

2. Tire (1) according to claim 1, wherein the metallic reinforcements of the outermost radially protective layer (311), form, with a circumferential direction (XX') tangent to the circumference of the tire, an angle APN whose absolute value is at least equal to 45°, preferably at least equal to 55°.

3. Pneumatic (1) according to claim 1, wherein the metallic reinforcements of the outermost radially protective layer (311) have a diameter of at least 2.5 mm, preferably at least 3.5 mm.

4. Pneumatic (1) according to claim 1 or 2, wherein the breaking strength FR of the metallic reinforcements of the outermost radially protective layer (311), is greater than 4000 N.

5. Pneumatic (1) according to any one of the preceding claims, wherein the metallic reinforcements of the innermost radially protective layer (312) have the same diameter and breaking strength as the metallic reinforcements of the outermost radially protective layer (311).

6. Pneumatic (1) according to any one of the preceding claims, wherein the pitch of the metal reinforcements of the innermost radially protective layer (312) is equal to the pitch of the metal reinforcements of the outermost radially protective layer (311).

7. Pneumatic (1) according to any one of the preceding claims, wherein the angle formed by the metallic reinforcements of the innermost radially protective layer (311) is at least equal to 35°, preferably at least equal to 45°, preferably at least equal to 55°.

8. Tire (1) according to any one of the preceding claims, the tread (2) being directly adjacent to the outermost radially outermost protective layer (311), wherein the elastic modulus Mal measured at 10% elongation at 23°C of the rubber compound of the tread (2) directly adjacent to the outermost radially outermost protective layer at the center of the tread, is at least equal to 0.65 times the elastic modulus Ma2 measured at 10% elongation at 23°C of the calendering compound of the outermost radially outermost protective layer (311).

9. Pneumatic (1) according to any one of the preceding claims, wherein the metallic reinforcements of the protective layers are desaturated.

10. Pneumatic (1) according to any one of the preceding claims, wherein the reinforcing elements of the working layers are desaturated.

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