Abstract:
Method for determining the transverse curve of a receiving surface of generally cylindrical form designed, during the assembly of the tire blank, to receive the components forming a crown belt in which threads are placed at zero degrees relative to the longitudinal direction, the threads being continuously wound without tension. The elongation rate (A) to be applied to a turn of a zero-degree thread is determined according to the desired pre-tension (A=f(T)), according to its axial position in the tire. Depending upon the radial position (Rf) of the thread of the said turn in the tire fitted into its mould, the initial radial position (Ri=Rf/(1+A)) is determined so that the thread of the turn in question sustains the desired elongation rate during forming in the press. The transverse profile (Rfdp) of the receiving surface is determined, in the axial location of the said turn, by subtracting from the initial position of the thread (Ri) the thickness (e) of the components placed radially inside the turn of the said zero-degree thread (Rfdp=Rf/(1+f(T)) e).
Abstract:
A tire wherein the reinforcing cords of the carcass, in the part situated between the anchoring zone of the carcass and the sidewall, are in contact with at least one layer of cushion compound having a high modulus of elasticity on the axially outer side and a low modulus of elasticity on the axially inner side and in the sidewall.
Abstract:
A tire wherein the reinforcing cords of the carcass, in the part situated between the anchoring zone of the carcass and the sidewall, are in contact with at least one layer of cushion compound having a high modulus of elasticity on the axially outer side and a low modulus of elasticity on the axially inner side and in the sidewall.
Abstract:
A tire having a crown which includes a ply of circumferentially oriented, helically wound reinforcing threads. This ply is arranged such that in sensitive zones, for example, beneath the grooves of the tread pattern, the laying pitch of the circumferential reinforcing threads is greatly increased. This substantially reduces the risks of damage to the circumferential reinforcing threads in these zones.
Abstract:
The tire has a single layer of cushion compound between the cords of the carcass reinforcement that are furthest radially outward in the crown and the cords of the belting that are furthest radially inward in the crown. The single layer of cushion compound may have either a high modulus of elasticity of between 7 and 25 MPa for high crown rigidity or a low modulus of elasticity of less that 6 MPa for reduced hysteresis energy loss.