Tires with improved wear properties and improved rolling resistance

Abstract

The invention relates to a tire comprising a crown reinforcement formed by at least two working crown layers (41, 43) of reinforcing elements and at least one layer (42) of circumferential reinforcing elements. According to the invention, the tread has at least one longitudinally oriented notch (8) and at least one transversely oriented notch (10), the depth of said at least one longitudinally oriented notch and at least one transversely oriented notch measured on a brand new tire greater than or equal to 40 percent of the tread thickness, the ratio of the width of said at least one longitudinally oriented notch measured at the base of said at least one longitudinally oriented notch to the width of said at least one longitudinally oriented notch measured at the tread surface is strictly greater than 1.2, in the ratio of the width of said at least one transversely oriented notch measured at the bottom of said at least one transversely oriented notch to the width of said at least one transversely oriented notch measured at the tread surface of a brand new tire is greater than or equal to 1, and the at least one working crown layer at least one calendered ply has a tensile modulus of elasticity at 10% elongation of less than 8.5 MPa, the at least one calendered ply of said at least one working crown ply is tan(δ) max The indicated maximum tan(δ) value is less than 0.100.

Description

technical field [0001] The present invention relates to tires with radial carcass reinforcement, and more particularly to tires, for example intended to equip vehicles carrying heavy loads traveling at sustained speeds, such as trucks, tractors, trailers or coaches. Background technique [0002] In heavy tyres, the carcass reinforcement is usually anchored on either side in the bead area and is radially covered by a crown reinforcement consisting of at least two superimposed layers of The layers are formed by threads or cords parallel in each layer and crossing from one layer to the next so as to form an angle with the circumferential direction of between 10° and 45°. Said working layer forming the working reinforcement may further be covered by at least one layer called protective layer formed by reinforcing elements, advantageously metallic and stretchable and called elastic Reinforcement elements. It may also comprise layers of wires or cords of low elongation at an ang...

AI Technical Summary

Problems solved by technology

[0025] The inventors have demonstrated during experiments that the size of the concealed voids including the longitudinal and transverse cuts (both types of cuts) can be relatively small for the same application compared to a similar tire not comprising such concealed voids. ) in combination may cause reduced performance in terms of wear and irregular wear shapes

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