TYRE FOR A CIVIL ENGINEERING VEHICLE, COMPRISING A LEVEL-WOUND CROWN REINFORCEMENT WITH METAL REINFORCEMENTS

摘要

The present invention relates to a tyre for a civil engineering vehicle, which comprises an at least partially level-wound crown reinforcement with metal reinforcements and is compatible with a use under high load and on aggressive soils. According to the invention, the reinforcements of the crown layers (211, 212) are metallic and are wound, in the form of a strip (5) of width W, in a zigzag circumferential trajectory according to a periodic curve (7) and extend over a number N of periods P distributed over a number T of circumferences 2ΠR and satisfying the two equations N*(W/sinA) = 2ΠR*t, wherein 0.6 ≦ t ≦ 1 and N*P=2ΠR*T, so as to constitute a bilayer (21). Furthermore, for at least 40% of the axially positioned strip crossovers (53) and with respect to the circumferential direction (XX') at an axial distance L1 being at most equal to 0.25 times the amplitude L of the periodic curve (7), the circular portion of the bilayer (213), which is centered on the strip crossover (53) and has a radius R1 equal to twice the width W of the strip (5), comprises Ne outer strip crossovers and Ni inner strip crossovers, such that |Ne-Ni|/(Ne+Ni)= 0.3.