A system (10) for butt-joining two or more rubber strips (B1, B2) selected in accordance with a predetermined rubber mixture recipe in order to feed at least one extruder with a complex strip of rubber material (B.sub.12) made from the butt joined rubber strips is disclosed. The system includes at least one conveyor that transports the rubber strips from an inlet (12) of the system to an outlet (14) of the butt-joining system; a frame (18) that operationally supports the conveyor to allow the continuous transport of the rubber strips and also to allow the simultaneous butt-joining of the rubber strips fed to the system; and a roller system (20) that butt-joins the rubber strips without penetration. The invention also relates to a process for butt-joining rubber strips that is performed by the system.

A pneumatic tire including an innerliner member applied on a tire inner circumferential surface, the innerliner member being constituted from an at least three-layer structure including a film having a main component of a thermoplastic resin or a thermoplastic elastomer containing a blend of a thermoplastic resin and an elastomer, and rubber sheets layered on both sides of the film; and a lap splice portion in which tire circumferential direction end portions of the film are overlapped with the rubber sheets inbetween. The rubber sheet on the tire cavity side of the innerliner member disposed on the tire cavity side in the lap splice portion is formed longer along the tire circumferential length than the film adjacent thereto.

Provided is a pneumatic tire having an innerliner member attached to a tire inner circumferential surface, the innerliner member constituted from at least three layers including a film having, as a main component, a thermoplastic resin or a thermoplastic elastomer composition containing a blend of a thermoplastic resin and an elastomer, and rubber sheets layered on both sides of the film, the tire including a lap splice portion in which tire circumferential direction end portions of the film are overlapped with the rubber sheets interposed therebetween. The rubber sheet on the tire cavity side of the innerliner member disposed on the tire cavity side in the lap splice portion is formed shorter along the tire circumferential length than an adjacent film.

In a pneumatic tire production method including a step of overlapping end portions of a sheet laminate and vulcanization-molding the tire, the sheet laminate being obtained by layering an elastomer layer and a sheet of a thermoplastic resin composition containing a thermoplastic resin or a blend of a thermoplastic resin and an elastomer, after the end portions of the sheet laminate are overlapped, the overlapped portion of the sheet laminate is compression-bonded at a temperature of not less than a glass transition temperature Tg of the thermoplastic resin and not greater than 120° C.

A system (10) for butt-joining two or more rubber strips (B1, B2) selected in accordance with a predetermined rubber mixture recipe in order to feed at least one extruder with a complex strip of rubber material (B12) made from the butt joined rubber strips is disclosed. The system includes at least one conveyor that transports the rubber strips from an inlet (12) of the system to an outlet (14) of the butt-joining system; a frame (18) that operationally supports the conveyor to allow the continuous transport of the rubber strips and also to allow the simultaneous butt-joining of the rubber strips fed to the system; and a roller system (20) that butt-joins the rubber strips without penetration. The invention also relates to a process for butt-joining rubber strips that is performed by the system.

Cord ply joiner for a tire includes a first pressurizer having first pressing member and first pressure receiving member in upper and lower sides, and a second pressurizer having second pressing member and second pressure receiving member in the upper and lower sides. A first code ply positioning mechanism positions a first code ply by bringing a tail end of the first code ply into contact with a side surface of the second pressure receiving member, a first code ply fixing mechanism lowers the cord end pressing member so the first cord ply is fixed, and a second code ply positioning mechanism positions the tip of the second code ply by bringing the tip into contact with a side surface of the cord end pressing member. The first pressurizer and the second pressurizer are brought close to each other, whereby a shearing force is applied to an overlapped portion.

A pneumatic tire 1 comprises a carcass 6 comprising at least one carcass ply 6A extending between bead portions 4 via sidewall portions 3 and a tread portion 2. The carcass ply 6A comprises strip-shaped ply pieces 11 longer in a tire radial direction than in a tire circumferential direction arranged circumferentially. Each of the ply pieces 11 comprises a plurality of carcass cords 12 arranged in parallel in the tire radial direction and at least partly overlapping each other with the ply pieces 11 circumferentially adjacent. At least one of the carcass cords 12 arranged in at least one of side edge portions 11e in the tire circumferential direction of each of the ply pieces 11 having a diameter (Ce) smaller than a diameter (Cc) of at least one of the carcass cords 12 arranged in a center portion 11c of each of the ply pieces 11.

A method for manufacturing a pneumatic tire may include lap-splicing end parts of a laminate sheet in which a sheet obtained from a thermoplastic resin or a thermoplastic resin composition of a thermoplastic resin blended with an elastomer is laminated with a rubber that undergoes vulcanizing adhesion with the thermoplastic resin or the thermoplastic resin composition. After the sheet obtained from the thermoplastic resin or the thermoplastic resin composition is cut into lengths to be supplied for lap-splicing, and at a stage before tire vulcanization molding, distal end parts of the sheet obtained from the thermoplastic resin or the thermoplastic resin composition are sharpened with a thermal treatment.

Cord ply joiner for a tire includes a first pressurizer having first pressing member and first pressure receiving member in upper and lower sides, and a second pressurizer having second pressing member and second pressure receiving member in the upper and lower sides. A first code ply positioning mechanism positions a first code ply by bringing a tail end of the first code ply into contact with a side surface of the second pressure receiving member, a first code ply fixing mechanism lowers the cord end pressing member so the first cord ply is fixed, and a second code ply positioning mechanism positions the tip of the second code ply by bringing the tip into contact with a side surface of the cord end pressing member. The first pressurizer and the second pressurizer are brought close to each other, whereby a shearing force is applied to an overlapped portion.

A pneumatic tire includes a strip member which extends in a tire circumferential direction, with both ends thereof reaching each bead portion, and a belt layer disposed in a tread portion on an outer side in the tire radial direction of the strip members. The strip members are divided in the tire width direction, with each of the divided strip members having joints that join in the tire circumferential direction. The relative positions of the joints are disposed at less than 20 in the tire circumferential direction within the region of the maximum width TW in the tire width direction of the belt layer.