Flexible reinforcing structures

Claim 1

**WARNING** start of CLMS field may overlap end of DESC **. ferentially around the tyre and traverse the equatorial plane at an angle of 20 . The cords 22 are formed individually from one or the other of two materials, one of which materials is metallic and the other of which materials is glass. The metallic cords are designated 22s and the glass cords are designated 22g. The cords 22 are arranged in a single layer in which a pair of glass cords 22g alternate with a single steel cord 22s. In the embodiment of Figure 3 the cords 22 are arranged in two layers with the glass cords 22g above the steel cords 22s. The glass cords 22g are arranged in pairs above but between a pair of steel cords 22s. Thus when viewed in plan, i.e. in the direction of arrow A of Figure 1, the pair of glass cords 22g alternate with a single steel cord 22s. The use of glass cords in the reinforcing structure reduces the weight and cost of the structure as compared with one formed wholly from cords of a metal such as steel whilst the presence of some metal, preferably steel, cords enables adequate reinforcing strength to be obtained without the use of an otherwise large number of glass or other cords which would increase the bulk of the reinforcing structure. Accordingly, the number of metal cords used in relation to the number of glass cords is to be selected depending on the required strength to weight and strength to volume ratios of the reinforcing structure. It has been found that a particularly suitable reinforcing structure for use as a reinforcing belt of a radial ply tyre can be formed by a weftless construction of 1 X 4 x 0.25 mm steel cords each alternating with two ECG 75-510 glass filament cords embedded in a rubber-like material such as resorcinol/formaldehyde latex composition arranged in the form of two layers embedded in styrene butadiene rubber. In the designation ECG 75-5/0 (as supplied by Pittsburg Plate Glass) for the glass filament cords, E indicates that the glass composition is electrical C indicates that filaments are continuous G indicates a filament diameter in the range 0.00035 to 0.00040 75 indicates a spun yarn linear density or count of 7,500 yards/lb. -5 indicates that the cord comprises 5 strands twisted together /0 indicates that the cord is a simple bunch of 5 strands. WHAT WE CLAIM IS: 1. A flexible reinforcing structure comprising reinforcing cords embedded with mutually parallel alignment in a flexible polymeric material, said cords being individually one or the other of two materials, one of which materials is glass and the other of which materials is metallic, said cords being arranged so that in plan view two or more cords of a first of said two materials alternate with one or more cords of the second of said two materials.