The invention relates to a rubberized reinforcing ply (1) for articles consisting of an elastomeric material, preferably for vehicle tires, wherein the reinforcing ply (1) has a multiplicity of textile strengthening members (2) which are arranged parallel to and spaced apart from one another, wherein each textile strengthening member (2) is composed of at least one twisted multifilament yarn composed of the material viscose. The reinforcing ply (1) satisfies the following condition: (D.sup.2/E.sub.0) in mm corresponds to a value in a range from 0.30 mm to 0.45 mm, and the reinforcing ply (1) has a strength of 11 kN/dm<x<20 kN/dm, where D is the diameter of the textile strengthening member (2) in mm and lies in a range from 0.38 mm to 0.48 mm, and where E.sub.0=100/epdm.

A pneumatic tire comprises a carcass layer, a belt layer disposed on the outer side in the tire radial direction of the carcass layer, and tread rubber disposed on the outer side in the tire radial direction of the belt layer. The belt layer is formed by laminating a pair of cross belts having belt angles with an absolute value from 10 to 45 both inclusive and mutually opposite signs, and a circumferential reinforcing layer having a belt angle within a range of 5 relative to the tire circumferential direction. The distance (Gcc) from the tread profile to the tire inner circumferential surface along the tire equatorial plane and the distance (Gsh) from the tread edge to the tire inner circumferential surface have a relationship satisfying 1.10Gsh/Gcc. The groove depth (Dsh) and under-groove gauge (UDsh) of the outermost circumferential main groove have a relationship satisfying 0.20UDsh/Dsh.

Technique to increase the endurance of tires comprising two crossed working layers (41, 42), comprising mutually parallel reinforcing elements (411, 421) forming, with the circumferential direction (XX) of the tire, an angle at least equal to 20 and at most equal to 50, the reinforcing elements being made up of individual metal threads or monofilaments having a cross section at least equal to 0.20 mm and at most equal to 0.6 mm. The end of the monofilaments comprises flats such that they reduce the shear forces in the rubber compounds of the tire under compressive loading.

A radial tire comprises a multilayer composite laminate (10) comprising at least three superposed layers of reinforcers (110, 120, 130), the reinforcers being unidirectional within each layer and embedded in a thickness of rubber (C1, C2, C3, respectively), with a first layer of rubber (C1) comprising at least one row of heat-shrinkable circumferential textile reinforcers (110), for example made of nylon or polyester. The first layer radially (in the direction Z) surmounts two other layers (C2, C3) comprising metal reinforcers (120, 130) which are crossed from one layer to the next, in the form of steel monofilaments of a diameter between 0.20 mm and 0.50 mm. The reinforcers (110) made of heat-shrinkable textile material are tapes of thickness denoted T between 0.1 mm and 1 mm, and of thickness denoted W between 2 and 50 mm.

A radial tire for a heavy vehicle of construction plant type, and aims to increase the resistance of the crown thereof to attack The tire (1) for a heavy vehicle of construction plant type has a crown reinforcement (3) radially on the inside of a tread (2) and radially on the outside of a carcass reinforcement (4), the crown reinforcement (3) has, radially from the outside to the inside, a protective reinforcement (5) and a working reinforcement (6). The protective reinforcement (5) has at least one protective layer (51, 52) comprising elastic metal reinforcers that have a breaking strength Fm and a section of diameter D and are spaced apart in pairs by a spacing P at least equal to the diameter D. According to the invention, the ratio A=(PD)/D is at least equal to 0.25 and at most equal to 1, the ratio B=(Fm/P)/1000 is at least equal to 1.1 and at most equal to 2, Fm being expressed in N and P being expressed in mm, and the elastic metal reinforcers of the protective layer (51, 52) are multistrand ropes of structure 1N comprising a single layer of N strands wound in a helix.

A tire comprises at least first and second working plies (16, 18) respectively comprising first and second reinforcing elements (50, 52) in which at least one of the following relationships is satisfied:

4053E1+4720(D1.sup.4d11000)/E1 (I)

4053E2+4720(D2.sup.4d21000)/E2 (II)

where D1, D2 are the diameter of each reinforcing element (50, 52) made up of a metallic monofilament (66, 68), and D1 and/or D2 ranges from 0.34 to 0.38 mm, d1, d2 are the density of the reinforcing elements (50, 52), expressed in monofilaments per decimetre, and E1, E2 are the mean thickness of the working ply (16, 18), expressed in mm.

A rubber composition has an improved rolling resistance and is based on at least a diene elastomer comprising mainly at least one isoprene elastomer; a reinforcing filler comprising from 15 to 70 phr of carbon black having a BET specific surface area of less than 70 m.sup.2/g, and/or a COAN of less than 90 ml/100 g, and from 5 to 20 phr of silica; a salt of an alkaline-earth, alkali or lanthanide metal; and a crosslinking system; in which composition the carbon black to silica ratio is greater than 1.

Breaking energy test performance of lightweight tyres that have a good performance in terms of rolling resistance and having a nominal width at least equal to 135 mm and at most equal to 235 mm is increased. These tyres comprise two thin and lightened working layers (41, 42) comprising metal reinforcing elements (411, 421) made up of monofilaments having a linear breaking strength Rct at least equal to 300 daN/cm and at most equal to 400 daN/cm, and a single carcass layer (6) radially on the inside of the working layers. In order to improve performance in the breaking energy test, this carcass layer comprises textile reinforcing elements and has surface breaking energy at least equal to 1.75 J/cm.sup.2.

Tires comprising a hoop reinforcement (5) and 2 crossed working layers (41, 42) in which the breaking strength R.sub.C of each working layer (41, 42) is at least equal to 30 000 N/dm have improved endurance. The working layers comprise reinforcing elements made up of individual metal threads or monofilaments having a cross section at least equal to 0.20 mm and at most equal to 0.5 mm. The density of reinforcing elements in each working layer is at least equal to 100 threads per dm and at most equal to 200 threads per dm. The tire also comprises axially exterior cuts (25). At least one of the two axially exterior portions of the tread comprises a rubbery material having a Shore hardness at least equal to 48 and at most equal to 60.

A radial tire (1) for a heavy-duty vehicle of construction plant type, and to reduce the risk of tire tread separation when running over sharp stones, while at the same time ensuring that the crown reinforcement exhibits good resistance to cracking. The tire (1) has a protective reinforcement (50) having three protective layers (51, 52, 53), comprising metal reinforcers that respectively have a diameter (D1, D2, D3) and are distributed at an axial spacing (P1, P2, P3). According to the invention, with Alpha1, Alpha2 and Alpha3 being the angles of the reinforcers of the respective layers (51, 52, 53) with the circumferential direction, the following relationships are satisfied:
15|Alpha1|40
15|Alpha2|40
Alpha1*Alpha20
35|Alpha3|75
As regards the differences between the angles of the reinforcers of the protective layers, the following relationship in terms of absolute values applies:
|(Alpha1Alpha3)|10
|(Alpha2Alpha3)|10.