A mould for vulcanising tyres for vehicle wheels, comprising—at least one sidewall plate (3) on which a moulding surface (4) is defined,—a removable insert (10) arranged to be received in a seat (5) which is made in said sidewall plate and open on said moulding surface, said insert comprising a main body (11; 111) on which a base surface (12) is defined which is intended for contacting a portion of a sidewall (52) of the green tyre, and—a retaining member (20) for retaining said insert (10) inside said seat. The retaining member comprises at least one locking element which is mounted on one out of said insert and said sidewall plate and can be moved in an operating direction (Y) between a locking position, in which said insert is retained inside said seat, and a release position, in which said insert is free to leave said seat.

The present invention relates to an insert (10) for a mould (1) for vulcanising tyres for vehicle wheels, the insert being arranged to be received in a seat (5) formed on a moulding surface (4) of the mould (1) and comprising a base surface (12) from which a plurality of projections (20) extends. Each projection comprises a lateral surface (21) extending away from said base surface (12), which lateral surface defines a tapered profile of said projection (20) away from said base surface (12), is inclined at an angle of between 10° and 25° with respect to a direction (X) perpendicular to said base surface (12), and has a roughness of between 4 and 11 μm. The invention is also related to a process for producing said insert and to a process for producing a tyre for vehicle wheels.

An insert (36) is designed to be incorporated in the composition of a fitting element (24) and to form part of the molding surface (40) of the fitting element, the molding surface comprising at least one intersection (32) of at least a first (42) and a second (44) projecting pattern. The insert comprises a junction (46) which is designed to be joined with a molding element (38) integral with the body (34) of the fitting element, the junction (46) dividing the second pattern (44) into a first (48) and a second (50) part, the insert (36) forming the first pattern (42) and the first part (48) of the second pattern (44), and the molding element (38) forming the second part (50) of the second pattern (44), the junction (46) going away from the intersection (32).

A pneumatic tire includes sipes disposed in a land portion formed in a tread portion, and pin holes for stud pins disposed in the land portion. The sipes are disposed at positions where a distance Ds from the pin hole and a diameter Dp of the pin hole satisfy (Ds/Dp)≥4.0. A sipe in which the distance Ds from the pin hole and the diameter Dp of the pin hole satisfy (Ds/Dp)≤5.0 is defined as a pin hole neighboring sipe. A sipe of which the distance Ds from the pin hole is the smallest, among the sipes in which the distance Ds from the pin hole and the diameter Dp of the pin hole satisfy (Ds/Dp)>5.0, is defined as a normal sipe. The pin hole neighboring sipe is formed in a high rigidity shape having higher rigidity than the normal sipe.

The projection portion includes a straight portion extended linearly in a predetermined direction, a first inclined portion inclined to spread toward an outer side in the predetermined direction from one end of the straight portion, and a second inclined portion inclined to spread toward an outer side in the predetermined direction from another end of the straight portion. A period defined by a length of the projection portion in the predetermined direction is 0.8 times to 2.0 times as large as a sipe depth defined by a length of the sipe between the wheel tread of a block and a bottom of the sipe.

A tire includes a projection disposed between a tread end and a maximum width position on a side surface. The projection includes a groove that extends through an outer side surface in a circumferential direction. The tire is preferably produced by using a mold which has a first part and a second part and in which a dividing line between the first and the second parts extends in the circumferential direction and comes into contact with the side surface, and the groove preferably overlaps an imaginary line, on the side surface, corresponding to the dividing line. A width of the groove is preferably not less than 1.5 mm and preferably not greater than 3.0 mm.

A method for manufacturing a mold element using a manufacturing device comprising a die and a counter-mold defining a molding cavity in the closed position, comprises: opening the manufacturing device; placing at least one insert 22, produced by laser sintering, against a molding surface of the die; mounting at least one wedge 28 on the die so as to bear against said insert in order to immobilize it relative to said molding surface; closing the manufacturing device, the counter-mold pressing onto said wedge in order to keep said insert pressed against said molding surface; injecting aluminium into the molding cavity of the manufacturing device; opening the manufacturing device; and extracting from the manufacturing device the mold element provided with a molding face formed by at least part of said insert and by the aluminum.

A pneumatic tire includes a longitudinal ridge extending along the tire radial direction and projecting outward from the surface of the tire side portion toward an outside of a tire width direction. A plurality of longitudinal ridges are provided along the tire circumferential direction, and a tire radial direction inner end of the longitudinal ridge is located outside the tire radial direction than the maximum width position. The tire radial direction outer end of the longitudinal ridge is located outside the tire radial direction than a straight line L2 orthogonal to a straight line L1.

The tire mold comprises lower 12 and upper portions 14 which are movable relative to one another between a close-together position for molding the tire and a distanced position for extracting said tire from the mold, and a plurality of central sectors 16 which are in axial contact with the lower 12 and upper portions 14 in their close-together molding position. For each sector 16, the mold comprises an upper member 22 for permanently coupling said sector to the upper portion 14, and a lower member 20 for temporarily coupling said sector to the lower portion 12, said coupling members 20, 22 being configured so as to obtain, during an axial distancing movement of the lower 12 and upper portions 14 from their close-together molding position, a radial displacement of said sector 16 toward the outside followed by an angular pivoting.

Tyre curing mould (20) comprising two shells (21) that are each intended to mould a sidewall of the tyre and a ring of sectors (22) that are intended to mould a tread of the tyre, each sector (22) having a lining (23) and two arc-shaped segments (27).

According to the invention, each segment (27) is arranged so as to fill a clearance at an interface between the lining (23) and a shell (21), and so as to not be coincident with a moulding surface (24) of the curing mould.