Provided is a fiber for rubber reinforcement that can be produced using a bio-derived raw material and hardly breaks even when compounded with a rubber material. A first fiber for rubber reinforcement uses a protein fiber containing a hydrophobic protein. A second fiber for rubber reinforcement uses a protein fiber having an initial tensile modulus of elasticity of 2.0 GPa or more when wet. These fibers for rubber reinforcement preferably have a coating layer made of a water-based adhesive composition on the surface thereof.

A multicomposite reinforcer (R1, R2) comprises one or more monofilament(s) (10) made of glass-resin composite comprising glass filaments (101) embedded in a crosslinked resin (102), with a glass transition temperature Tg.sub.1. A layer of a thermoplastic material (12), the glass transition temperature of which, denoted Tg.sub.2, is greater than 20° C., covers said monofilament or, if there are several, individually covers each monofilament or collectively covers all or at least some of the monofilaments. Said monofilament or, if there are several, all or at least some of the monofilaments has the following features: a temperature Tg.sub.1 equal to or greater than 190° C.; an elongation at break A.sub.(M) equal to or greater than 4.0%; and an initial tensile modulus E.sub.(M) greater than 35 GPa. A multilayer laminate may comprise such a multicomposite reinforcer. A pneumatic or non-pneumatic tyre may be reinforced with such a multicomposite reinforcer or multilayer laminate.

The invention relates to a metallic reinforcing cord (10) for tyres for vehicle wheels, comprising at least two metallic wires (11) twisted together with a predetermined twisting pitch (P). The metallic reinforcing cord (10) has a part load elongation greater than 3%, preferably greater than 3.5%.

The present invention provides a pneumatic tire in which a steel cord carcass ply composed of an ultrafine wire having a filament diameter of 0.15 mm or less is used as a reinforcing material, and the carcass ply is positioned between the bead cords without turn-up of the carcass ply for turning up it through an annular bead bundle on an upper side of the carcass ply, such that side rigidity is maintained even when replacing two conventional fiber carcass plies with one steel carcass. Thereby, rather than the conventional turn-up method of turning up the carcass ply on the upper side of the annular bead bundle, the carcass ply passes through the bead bundles as shown in FIG. 3, such that a deformation energy of the bead portion is minimized and a rolling resistance is maximized. The tire of the present invention is characterized by satisfying a correlation equation between a height Bh1 of an inner bead bundle position and a height Ah of the bead portion including an apex of 1.2<Ah/Bh1<4.5.

A tire (1) for a heavy construction plant vehicle with satisfactory compromise between the breaking strength of its circumferential hoop reinforcement (7), having an axial width LF and having a circumferential hooping layer (71, 72) with elastic metallic reinforcers having a structural elongation AS and a force at break FR, and forming an angle at most equal to 5° with the circumferential direction (XX), and the endurance of its working reinforcement (6), formed by two working layers (61, 62) with inextensible metallic reinforcers, the mean angle AM of which with the circumferential direction (XX′) is at least equal to 15° and at most equal to 45°. The axial width LF, the structural elongation As, the force at break Fr and the mean angle AM satisfy the relationship:

Zn/Z0*(T0+(a1+a2*As)/AM+b*LF*(AM−A0)/A0+c*AM)<Fr/CS, where Zn is the nominal load, Z0=100 t, T0=7000 N, a1=−230,000 N*°, a2=−160,000 N*°/%, b=−34,000 N/m, A0=29°, c=550 N/°, CS>=1.

A tire for a heavy-duty vehicle of construction plant type comprises a crown reinforcement (35) radially on the inside of a tread (10) and radially on the outside of a carcass reinforcement (50). The crown reinforcement (35) comprises: at least one “low-modulus” layer (20) formed of elastic metal reinforcers having a structural elongation at least equal to 0.4%, and a total elongation at break at least equal to 3%, and a tensile elastic modulus of between 40 GPa and 130 GPa; at least one “rigid” layer (30) formed of rigid metal reinforcers, the structural elongation of which is less than or equal to 0.2% and the tensile elastic modulus of which is between 140 GPa and 200 GPa. The ratio of the breaking tension of the rigid layer to that of the low-modulus layer is greater than or equal to 1.2.

The invention relates to a metallic reinforcing cord (10) for tyres for vehicle wheels, comprising: —a) a plurality of metallic wires (11) twisted to one another with a single twisting pitch (P), or—b) a single metallic wire twisted with at least one second metallic wire with a single twisting pitch, or—c) a plurality of first metallic wires twisted to one another with a first twisting pitch to define a first strand of metallic wires and at least one second metallic wire twisted with said first strand of metallic wires with a second twisting pitch equal to or different from the first twisting pitch. The metallic reinforcing cord (10) has a part load elongation greater than or equal to 1%.

A pneumatic tire includes at least one carcass layer between bead portions on an inner side in a radial direction of sidewall portions on both sides of a tread portion extending in a circumferential direction and having an annular shape, and the carcass layer includes carcass cords formed of organic fiber cords obtained by intertwining a filament bundle of organic fibers. The carcass layer includes turn-up portions formed by being turned back at an end portion of the bead portions to an outer side in a tire width direction. The carcass cords have an elongation at break EB satisfying EB≥15%, a cap tread rubber compound of the tread portion has a 300% modulus MD satisfying 4 MPa≤MD≤13 MPa, and the elongation at break EB and the 300% modulus MD satisfy 600≤40×MD+20×EB (%)≤1300.

A monofilament made of glass-resin composite has improved properties in compression, in particular at high temperature, and comprises glass filaments embedded in a crosslinked resin. The glass transition temperature of the resin is equal to or greater than 190° C. The elongation at break of the monofilament, measured at 23° C., is equal to or greater than 4.0%. The initial tensile modulus of the monofilament, measured at 23° C., is greater than 35 GPa. The real part of the complex modulus of the monofilament, measured at 190° C. by the DMTA method, is greater than 30 GPa. Pneumatic or non-pneumatic tires are reinforced with such a composite monofilament.

The tire includes a tread that has a contact face of a width TW and is provided with a groove of a depth D. The tread has a center region and a pair of shoulder regions. The shoulder regions each have a shoulder rubber layer of a thickness is made of a shoulder rubber composition. A shear storage modulus G′ of the shoulder rubber composition is less than or equal to 1.0 MPa. The tire also has a cap ply whose cable extends generally in circumferential orientation and is positioned radially inbetween the tread and the ply at least in a region corresponding to the shoulder regions of the tread and the ply. A force F.sub.5% of the cap ply is greater than 900 N per 10 mm of a cap ply width under 5% strain in a direction cable of the cap ply is extending.