Crown For Aircraft Tire
Tire for an aeroplane and, in particular, the crown thereof which comprises a tread ( 1 ), a textile crown reinforcement ( 2 ) and a textile carcass reinforcement ( 4 ). In order to optimize the number of landings, in the equatorial plane, the thickness (E 1 ) of the tread is at least equal to 1.1 times the thickness of the working reinforcement and the thickness (E 5 ) of the carcass is at least equal to 1.5 times the thickness (E 3 ) of the working reinforcement, the reinforcing elements of the working layers ( 31, 32, 33 ) having a tenacity at least equal to 90 cN/tex.
1 . Tire for an aeroplane, comprising:
a tread having a centre thickness that is measured in the equatorial plane, passing through the middle of the tread and perpendicular to the axis of rotation of the tire, between the radially outermost point of the tread and the radially outermost point of a crown reinforcement radially on the inside of the tread;
the crown reinforcement comprising at least one working reinforcement;
the working reinforcement comprising at least one working layer that has an axial width, measured over the working layer having the greatest axial width, at least equal to ⅔ of the maximum axial width of the tire, and having a centre thickness in the equatorial plane that is measured between the radially outermost point of the radially outermost working layer and the radially innermost point of the radially innermost working layer;
the working layers comprising textile reinforcing elements;
a carcass reinforcement, radially on the inside of the working reinforcement, comprising at least one carcass layer and having a centre thickness in the equatorial plane that is measured between the radially outermost point of the radially outermost carcass layer and the radially innermost point of the radially innermost carcass layer;
the carcass layers comprising textile reinforcing elements;
a reinforcement that is formed by the working reinforcement and the carcass reinforcement and has a centre thickness in the equatorial plane that is measured between the radially outermost point of the radially outermost working layer and the radially innermost point of the radially innermost carcass layer,
wherein the centre thickness of the tread is at least equal to 1.1 times the centre thickness of the reinforcement formed by the working reinforcement and the carcass reinforcement,
wherein the centre thickness of the tread is at least equal to 1.5 times the centre thickness of the working reinforcement, and
wherein the reinforcing elements of the working layers have a tenacity at least equal to 90 cN/tex.
2 . The airplane tire according to claim 1 , wherein the centre thickness of the tread is at least equal to 4.2 times the centre thickness of the carcass reinforcement, and wherein the reinforcing elements of the carcass layers have a tenacity at least equal to 90 cN/tex.
3 . The airplane tire according to claim 1 , a straight line that passes through the centre of the tire, at the intersection of the equatorial plane and the axis of rotation, and through the point of the widest working layer, said point being positioned at an axial distance from the equatorial plane equal to 0.9 times the axial half-width of said layer, being defined as the measuring line for the shoulder thicknesses, the tread having a shoulder thickness measured between the radially outermost point, positioned on the measuring line, of the tread and the radially outermost point, positioned on the measuring line, of the radially outermost crown layer, the reinforcement formed by the working reinforcement and the carcass reinforcement having a shoulder thickness between the radially outermost point, positioned on the measuring line, of the radially outermost crown layer, and the radially innermost point, positioned on the measuring line, of the radially innermost carcass layer, wherein the shoulder thickness of the tread is at least equal to 1.2 times the shoulder thickness of the reinforcement.
4 . The airplane tire according to claim 1 , the carcass reinforcement having a shoulder thickness, measured between the radially outermost point, positioned on the measuring line, of the radially outermost carcass layer and the radially innermost point, positioned on the measuring line, of the radially innermost carcass layer, wherein the shoulder thickness of the tread is at least equal to 4.2 times the shoulder thickness of the carcass reinforcement.
5 . The airplane tire according to claim 1 , wherein the working layers comprise mutually parallel reinforcing elements that form an angle of between +20° and −20° with the circumferential direction.
6 . The airplane tire according to claim 1 , wherein the carcass layers comprise mutually parallel reinforcing elements that form an angle of between 80° and 100° with the circumferential direction.
7 . The airplane tire according to claim 1 , wherein the reinforcing elements of the working layers have a tenacity at least equal to 110 cN/tex.
8 . The tire according to claim 1 , wherein the reinforcing elements of the working layers consist of aromatic polyamides or a combination of aliphatic polyamides and aromatic polyamides.
9 . The airplane tire according to claim 1 , wherein the reinforcing elements of the carcass layers have a tenacity at least equal to 110 cN/tex.
10 . The airplane tire according to claim 1 , wherein the reinforcing elements of the carcass layers consist of aromatic polyamides or a combination of aliphatic polyamides and aromatic polyamides.
11 . The tire according to claim 1 , wherein the crown reinforcement comprises at least one protective reinforcement radially on the inside of the tread and radially on the outside of the working reinforcement which comprises at least one protective layer that comprises metal or textile reinforcing elements.