Tire, particularly for aiplanes, with crown reinforcement of textile cables and process for the manufacture thereof
AssigneeCompagnie Generale Des Etablissements Michelin
InventorJacques Musy
Life of this patent
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Abstract
When this airplane tire is mounted on its rim, its carcass reinforcement has a relative camber of convexity before inflation which is at most equal to 0.17 in the crown and at most equal to to 0.20 in the sidewalls. After inflation, the equilibrium curve of this carcass reinforcement is, at the level of the shoulders of the tire, located radially outwards of its equilibrium curve in the tire before inflation. The cables of the lateral plies of the tripartite crown reinforcement are very extensible and have a high coefficient of contraction under the heat at the temperature of vulcanization of the tire.
Claims18
A tire for airplanes having a carcass reinforcement formed of at least one ply of radial cables which is anchored to at least one bead ring in each bead and a tripartite crown reinforcement radially outwards adjacent to the carcass reinforcement and having a median portion in contact, at each of its edges, with a lateral portion, each of these three portions being formed of at least one ply of textile cables which are parallel in each ply and inclined by an angle of between 0.degree. and 30.degree. to the circumferential direction of the tire, the carcass reinforcement of the tire when mounted on its service rim and inflated to its service pressure but not under load having a relative camber of convexity in the crown of at most 0.12, preferably between 0.04 and 0.10, and a relative camber of convexity in the sidewalls of at most 0.14, the tire thus having a quasi-rectangular meridian profile and being characterized by the fact that when it is mounted on its service rim but not inflated, its carcass reinforcement has a relative camber of convexity in the crown of at most 0.17, preferably between 0.055 and 0.15, and a relative camber of convexity in the sidewalls of at most 0.20, and a length such that after inflation its equilibrium curve at the level of the shoulders is located radially outwards of its curve in the uninflated tire, and by the fact that the median portion of the crown reinforcement is formed of cables whose extensibility is low, preferably close to zero, and which have a low, preferably zero, coefficient of contraction under the heat at the temperature of vulcanization of the tire, while the cables of the lateral portions of the crown reinforcement are very extensible and have a high coefficient of contraction under the heat at the temperature of vulcanization of the tire.
A method for manufacturing a tire for airplanes having a carcass reinforcement formed of at least one ply of radial cables which is anchored to at least one bead ring in each bead and a tripartite crown reinforcement radially outwards adjacent to the carcass reinforcement and having a median portion in contact, at each of its edges, with a lateral portion, each of these three portions being formed of at least one ply of textile cables which are parallel in each ply and inclined by an angle of between 0.degree. and 30.degree. in the circumferential direction of the tire,
- comprising vulcanizing the tire in a vulcanization mold in which the carcass reinforcement and the crown reinforcement occupy approximately the same position as in the tire when mounted on its service rim and inflated to its service pressure but not under load, the curvature of the carcass reinforcement reaching a maximum at the shoulders and a minimum at the intersection of the carcass reinforcement with the equatorial plane of the tire, the carcass reinforcement in the tire in the vulcanization mold having a relative camber of convexity in the crown of at most 0.12, preferably between 0.04 and 0.10, and a relative camber of convexity in the sidewalls of at most 0.14;
- the tire thus having a quasi-rectangular meridian profile;
- and further comprising using a crown reinforcement in which the cables of the median portion have a low extensibility, preferably close to zero, and have a coefficient of contraction under the heat at the temperature of vulcanization of the tire which is low, preferably zero, and in which the cables of the lateral portions are very extensible and have a high coefficient of contraction under the heat at the temperature of vulcanization of the tire;
- when the tire is mounted on its service rim but not inflated, its carcass reinforcement has a relative camber of convexity in the crown of at most 0.17, preferably between 0.055 and 0.15, and a relative camber of convexity in the sidewalls of at most 0.20, and a length such that after inflation its equilibrium curve at the level of the shoulders is located radially outwards of its curve in the uninflated tire.
Dependencies are inferred from the claim text.