Breaker structures of radial tires

Claim 2

A pneumatic tire for vehicle wheels comprising a radial carcass, a tread and a breaker structure wherein said breaker structure comprises: -a. one strip of metal cords inclined with respect to equatorial axis of the tire at an angle ranging between 10° and 30°, said strip being so folded that a folding line is present at each lateral edge, said folded strip having a larger skirting of a width not smaller than that of the tire tread and two smaller skirtings, each of said smaller skirtings having a width ranging between 20% and 40% with respect to the width of said larger skirting; -b. at least one layer of textile cords arranged in a direction parallel to the equatorial axis of the tire, the material of said cords being such that it reduces in length when subjected to the action of heat, said layer being arranged in a radially outer position with respect to said metal cords and having a width smaller than the width of the larger skirting of said folded strip.

Claim 3

A pneumatic tire for vehicle wheels as in claim 1, wherein the opposite ends of said smaller skirtings are equidistant from the equatorial axis of the tire and are mutually spaced apart by a distance between 20% and 60% with respect to the width of the larger skirting of said folded strip.

Claim 4

A pneumatic tire for vehicle wheels as in claim 2, wherein the smaller skirtings of said folded strip lie in a radially outer position with respect to said larger skirting.

Claim 5

A pneumatic tire for vehicle wheels as in claim 2, wherein said layer of textile cords has a width which is larger than the distance between the opposite ends of the smaller skirtings of the folded strip of metal cords and is smaller than the width of the larger skirting of said strip.

Claim 6

A pneumatic tire for vehicle wheels as in claim 4, wherein the width of said layer of textile cords is between 50% and 80% with respect to the width of the larger skirting of the folded strip of metal cords.

Claim 7

A pneumatic tire for vehicle wheels as in claim 1, wherein the textile cords are nylon cords.

Claim 8

A pneumatic tire comprising a radial carcass having a crown portion, a tread surrounding the crown portion and a breaker structure reinforcing the tread disposed circumferentially about the crown portion between the carcass and tread, said breaker structure comprising a first ply of only one strip of metallic strands inclined at an angle of from 10° to 30° with respect to the equatorial axis of the tire, said strip being folded inwardly along each edge thereof to provide a folded over portion having a width of from 20% to 40% of the total width of the strip after folding, the folded strip underlying the tread throughout the width of the tread with the folded over portions facing the tread, and, disposed between the first ply and the tread, a second ply of at least one unfolded layer of heat shrinkable textile cords extending circumferentially about the crown portion of the tire substantially parallel to the equatorial axis of the tire, the width of the second ply being smaller than the folded width of the first ply but partially overlapping the folded over portions.

Claim 9

A pneumatic tire comprising a radial carcass having a crown portion, a tread surrounding the crown portion and a breaker structure reinforcing the tread disposed circumferentially about the crown portion between the carcass and tread, said breaker structure comprising a first ply of only one strip of metallic strands inclined at an angle of from 10° to 30° with respect to the equatorial axis of the tire, said strip being folded inwardly along each edge thereof to provide a folded over portion having a width of from 20% to 40% of the total width of the strip after folding, the folded strip underlying the tread throughout the width of the tread with the folded over portions facing the tread, and, disposed between the first ply and the tread, a second ply of at least one unfolded layer of heat shrinkable textile cords extending circumferentially about the crown portion of the tire substantially parallel to the equatorial axis of the tire, the width of the second ply being smaller than the folded width of the first ply but partially overlapping the folded over portions.

Claim 10

The tire of claim 7 wherein the second ply comprises two layers of textile cords and the layer adjacent to the first ply is of a larger width than the other layer.