Method for producing an asymmetrical tyre
View Patent ↗A method for manufacturing a tyre includes: assembling an unvulcanized tyre, the tyre including a crown, a first sidewall and a first bead, a second sidewall and a second bead, and a carcass reinforcement, each bead including a seat; and vulcanizing the unvulcanized tyre in a mould having an asymmetric configuration in order to obtain a vulcanized tyre, wherein the mould is such that, when the tyre is placed in the mould, in any meridian section, the seat of the first bead has an angle β 1 with a rotation axis A and the seat of the second bead has an angle β 2 with the rotation axis A, such that β 1 −β 2 3, with the angles β 1 and β 2 being expressed in degrees, with the angles β 1 and β 2 being defined, for each bead, relative to an axis Ox and Ox′ parallel to the rotation axis A oriented positively towards outside of the tyre, and with the angles β 1 and β 2 being positive when extending radially outwards.
1. A method for manufacturing a tyre, comprising steps of:
assembling an unvulcanized tyre, the tyre including a crown, a first sidewall and a first bead, a second sidewall and a second bead, and a carcass reinforcement, each bead including a seat; and
vulcanizing the unvulcanized tyre in a mould having an asymmetric configuration in order to obtain a vulcanized tyre,
wherein the mould is such that, when the tyre is placed in the mould, in any meridian section, the seat of the first bead has an angle β 1 with a rotation axis A and the seat of the second bead has an angle β 2 with the rotation axis a, such that:
β 1 −β 2 3,
the angles β 1 and β 2 being expressed in degrees, the angles β 1 and β 2 being defined, for each bead, relative to an axis Ox and Ox′ parallel to the rotation axis A oriented positively towards outside of the tyre, and the angles β 1 and β 2 being positive when extending radially outwards, and
wherein, when the tyre is placed in the mould, in any meridian section, the carcass reinforcement has a first point of inflection located at the first sidewall or at the first bead and a second point of inflection located at the second sidewall or at the second bead, and tangents (T 1 , T 2 ) at the points of inflection of the carcass reinforcement make angles α 1 and α 2 with the rotation axis A such that: α 1 −α 2 0.
2. A method according to claim 1 , wherein β 1 −β 2 10.
3. A method according to one of claims 1 and 2 , wherein, when the tyre is placed in the mould, in any meridian section, the carcass reinforcement has a first point of inflection located at the first sidewall or at the first bead and a second point of inflection located at the second sidewall or at the second bead, and tangents (T 1 , T 2 ) at the points of inflection of the carcass reinforcement make substantially identical angles α 1 and α 2 with the rotation axis A.
4. A method according to claim 1 , wherein α l −α 2 10.
5. A method according to claim 1 , wherein −35 α l −α 2 −10.
6. A method according to claim 1 , wherein the crown and portions of the sidewalls adjacent to the crown of the tyre are placed symmetrically relative to a mid-plane of the crown of the tyre in the mould.
7. A method according to claim 1 , wherein the first bead is designed to be located towards outside of a vehicle.
8. A method according to claim 1 , wherein the first and second sidewalls include reinforcing inserts that support a load in an event of loss of inflation pressure.
9. A method according to claim 1 , wherein the first bead has a diameter Φ 1 and the second bead has a diameter Φ 2 , such that: Φ 1 Φ 2 .
10. A method according to claim 9 , wherein a difference in diameters between the first and the second beads is 20 mm.