Abstract: PROBLEMS TO BE SOLVED The present invention is to provide a method for building a green tire and a device for cooling a green tire used therefor, which can cool the unvulcanized rubber ribbon sufficiently without sacrificing the adhesion performance to prevent an occurrence of the blister. SOLVING MEANS There is provided a method for building a green tire wherein at least during a period from start to finish of winding the unvulcanized rubber ribbon R, a cooling gas is continuously sprayed on an entire region of a surface of the rotating green tire under the process of building defined by a range in the width direction corresponding to an overall width of the unvulcanized rubber member 5 and by a predetermined angular range ? in the circumferential direction to cool the wound unvulcanized rubber ribbon R.

Abstract: A method for building a tire on a toroidal core, to include carcass plies with a high tensile resistance and bead portions with an improved rigidity, wherein the carcass plies (4, 10) are formed by continuously applying carcass cords (3, 9) onto an outer surface of the core over entire periphery thereof. An inner carcass ply (4) is formed by feeding the carcass cord (3) in a meridian direction of the core (1), and folding back the carcass cord (3) at each side portion of the core. Each radially inner peripheral portion (7) of the inner carcass ply (9) is turned-up radially outwards about a bead core (6). A skim rubber (8) is subsequently applying onto an outer surface of the inner carcass ply (9), which has been formed with the turned-up portions (7a). An outer carcass ply (10) is formed by feeding a carcass cord (4) in the meridian direction of the core (1) and folding back the carcass cord (4) at each side portion of the core (1), and applied onto an outer surface of the skim rubber (8).

Abstract: There are provided a method for manufacturing a tire which can suppress residual air and occurrences of bares, flow cracks and the like, which cause a reduction of the durability of a product tire, by flattening a stepped part formed at an overlapping portion of a tire component member under pressure to optimize a cross sectional shape of the overlapping portion, and an apparatus used for this method. The apparatus (1) comprises a building platform (2), a rubber strip extruder (3), and a pressing roller (4). A specified tire component member is formed by spirally winding a ribbon-shaped rubber strip 5 extruded by the rubber strip extruder (3) while making an overlapping portion to apply it on the building platform (2).

Abstract: A rigid core for manufacturing pneumatic tires includes a plurality of segments (2, 3), and a pair of retainer rings (5) engaging with a toroidal assembly (4) of the segments (2, 3) axially from both sides thereof, so as to hold the segments (2, 3) in the assembled state. The core defines the inner surface of the tire from formation of the tire up to the completion of the vulcanization thereof. The segments (2, 3) are each detachably divided into a center portion (2a, 3a) corresponding to the widthwise center portion of the tire and side portions (2b, 3b) corresponding to the widthwise side portions thereof. The core allows smooth removal of the segments even when the maximum inner surface width at the sidewall portion of the product tire is substantially larger than the minimum inner surface width at the bead portions thereof.

Abstract: An extruder system includes an extruder for axially extruding a rubber or plastic material in a barrel by rotation of an extrusion screw arranged in the barrel, and a gear pump driven by a rotational force for rotating the extrusion screw so that a predetermined amount of the extruded material is discharged by engagement of gears. The gear pump includes a driving pinion arranged coaxially to the extrusion screw and fixedly secured to a tip end of the extrusion screw, a driven pinion engaged with, and driven by the driving pinion and rotatable about a rotational shaft that is parallel to a rotational shaft of the extrusion screw, and a gear casing accommodating these pinions therein. The gear casing includes side plates arranged on both axial sides of the pinions and extending perpendicularly to the rotational shaft of the extrusion screw, and a casing body arranged between the side plates and enclosing a space on a radially outer side of the pinions.

Abstract: Tire vulcanizing method and mold, capable of suppressing increase in installation cost and effectively absorbing large fluctuation and change in the rubber volume. A green tire is vulcanized in a mold cavity (3) defined by a core (2) made of rigid a material and having an outer surface shape corresponding to the inner surface shape of a product tire, and also by a vulcanizing mold (1) which surrounds the core (2). At least a portion of the molding surface of a side ring member (6), which forms part of the vulcanizing mold (1), is moved in a direction for increasing the volume of the mold cavity.

Abstract: In producing a side-reinforced type runflat tire in which side reinforcing rubbers with generally crescent-shaped sections are interposed between a carcass and an inner liner, the first drums 11a, 11b on which the side-reinforcing rubbers are to be attached are so configured that their diameter do not substantially fluctuate along the axial direction. The expanding operation of the first drum, the mutually approaching operation of the first drums 11a, 11b, and the approaching operation of the bead gripping rings 30A are synchronized. As a result, there is provided a tire and a method of its production capable of being produced by a multi-size mixed flow production system consisting of minimum equipments and of preventing air inclusions and wrinkles between the carcass member 4A and the side-reinforcing rubber 2A.

Abstract: For manufacturing the laminated mold comprising the laminate (11) being formed of a plurality of thin sheets (11a) laminated on each other, laminate the thin sheets with the excess portions of respective thin sheets exceeding the profile of the tire crown portion on the side of contacting with the tire stepping face left, then remove the excess portions, form the sector mold by placing the laminate (11) with the excess portions removed in the holder, form the laminated mold having the annular read pattern by arranging a plurality of the sector mold in a peripheral direction of the tire so as to suppress formation of the stepped shape appearing on the tire profile comparing with the one as originally intended.

Abstract: For manufacturing the laminated mold comprising the laminate (11) being formed of a plurality of thin sheets (11a) laminated on each other, laminate the thin sheets with the excess portions of respective thin sheets exceeding the profile of the tire crown portion on the side of contacting with the tire stepping face left, then remove the excess portions, form the sector mold by placing the laminate (11) with the excess portions removed in the holder, form the laminated mold having the annular read pattern by arranging a plurality of the sector mold in a peripheral direction of the tire so as to suppress formation of the stepped shape appearing on the tire profile comparing with the one as originally intended.

Abstract: A pneumatic tire comprises a carcass comprised of at least one carcass ply containing a steel cord(s) arranged at a cord angle of 70-90° with respect to an equatorial plane of the tire and toroidally extending between a pair of bead cores and turned up around the bead core inward or outward in a radial direction to form a turnup portion, wherein a wrap part wrapping on a peripheral face of the bead core therealong is formed in the turnup portion of the carcass ply.

Abstract: A rigid core for manufacturing pneumatic tires includes a plurality of segments (2, 3), and a pair of retainer rings (5) engaging with a toroidal assembly (4) of the segments (2, 3) axially from both sides thereof, so as to hold the segments (2, 3) in the assembled state. The core defines the inner surface of the tire from formation of the tire up to the completion of the vulcanization thereof. The segments (2, 3) are each detachably divided into a center portion (2a, 3a) corresponding to the widthwise center portion of the tire and side portions (2b, 3b) corresponding to the widthwise side portions thereof. The core allows smooth removal of the segments even when the maximum inner surface width at the sidewall portion of the product tire is substantially larger than the minimum inner surface width at the bead portions thereof.

Abstract: A pneumatic tire comprises a carcass comprised of at least one carcass ply containing a steel cord(s) arranged at a cord angle of 70–90° with respect to an equatorial plane of the tire and toroidally extending between a pair of bead cores and turned up around the bead core inward or outward in a radial direction to form a turnup portion, wherein a wrap part wrapping on a peripheral face of the bead core therealong is formed in the turnup portion of the carcass ply.

Abstract: A tire comprising a tread layer comprised of a tread rubber and an electrically conductive band arranged in a widthwise middle portion thereof, and a method of producing the tire, wherein the tread rubber is made of a low-conductive continuous rubber ribbon circumferentially wound plural times, and the electrically conductive band is made of a high-conductive thin annular rubber sheet. Also, the electrically conductive band is arranged so as to extend in the widthwise region ranging from a part of the top face of the first tread rubber portion to a part of the bottom face of the second tread rubber portion, whereby the tire uniformity is improved and the production is possible in a multi-size mixed production system and the conductive path from the belt to the treading face can be surely formed at a low cost.

Abstract: A tire building system, which does not require prolonging tact time for tire building, specific occupying space for endless circulative traveling of a building carriage, and increasing noises and vibrations, and which is free from possibility of premature deterioration of carriage positioning accuracy. The system includes workstations configured to mount applicable tire components onto a building drum, respectively; a building carriage configured to support the building drum to thereby move the building drum among the respective workstations; and carriage guiding means for guiding a movement of the building carriage on a predetermined path. The carriage guiding means includes two inner and outer endless rails, and wheels provided on the building carriage, the wheels each being configured to roll on opposite side surfaces of associated one of the endless rails to thereby restrict a carriage position in a direction orthogonal to an extending direction of the endless rails.

Abstract: Tire building drum and tire building method, capable of assembling tire component members with high accuracy. A tire building drum is used, which includes at least one core body, which is disposed at an axial inside of a pair of bead lock means, and which comprises a plurality of sheets of rigid support members disposed in a toroidal shape and adapted to be displaced and thereby expanded or contracted. Bead cores are locked by the bead lock means, respectively, and a center portion of a carcass band is bulged while displacing the bead lock means close to each other. Back side portions of the carcass band are folded to radial outsides around the bead cores, respectively. The core body is then radially expanded to the maximum diameter while locking the bead cores, and tire component members are assembled onto the radially expanded core body.

Abstract: In the lamination of band-shaped uncured rubber materials to form a laminated rubber member having a given sectional shape by helically winding a band-shaped uncured rubber material extruded through an extruder on a rotating support, two or more rubber compositions indicating different moduli after the curing are used as a rubber material fed to the extruder, and a first rubber material is extruded through the extruder and helically wound on the support to form a first rubber layer, and the first rubber material and a second rubber material are continuously and simultaneously through the extruder so as to stepwise or gradually increase a blending ratio of the second rubber material to the first rubber material while holding the same extrusion sectional shape and helically wound on the first rubber layer while overlapping with at least a part of the first rubber layer to form a second rubber layer.

Abstract: A method of manufacturing a tire having first color characters or lines on at least one side wall part, includes the steps of stamping a second color side wall rubber and a first color side wall rubber on the side face of a carcass member formed in a toroidal shape by winding, a plurality of turns, a continuous second color rubber ribbon and a continuous first color rubber ribbon thereon, stamping a second color cover rubber on the outsides of the side wall rubbers by winding a rubber sheet whereon one turn in an annular shape, and molding a green tire, whereby the use of a large extrude can be eliminated, different types of tires can be efficiently manufactured since a size switching can be easily performed, the accuracies of the shape and the dimensions of the members thereof can be increased, the uniformity and the tire balance thereof can be increased, and the sharp profile of the first color characters or lines can be assumed, thus eliminating problems associated with the appearance.

Abstract: For manufacturing the laminated mold comprising the laminate (11) being formed of a plurality of thin sheets (11a) laminated on each other, laminate the thin sheets with the excess portions of respective thin sheets exceeding the profile of the tire crown portion on the side of contacting with the tire stepping face left, then remove the excess portions, form the sector mold by placing the laminate (11) with the excess portions removed in the holder, form the laminated mold having the annular read pattern by arranging a plurality of the sector mold in a peripheral direction of the tire so as to suppress formation of the stepped shape appearing on the tire profile comparing with the one as originally intended.

Abstract: A shaped rubber body with improved uniformity in terms of weight and/or physical properties is produced by extruding a rubber strip by a positive displacement extruding system that includes, as seen from an upstream side of the rubber strip, a screw extruder unit, a gear pump unit and an extrusion head unit with an extrusion nozzle, which are connected in series with each other. The rubber strip is fed to a rotating support along a substantially straight passage extending from the screw extruder unit to the extrusion nozzle of the extrusion head unit, passed through a gap defined between a pair of pressure roll, and applied onto an outer surface of the support by one of the pressure rolls.

Abstract: A pneumatic radial tire comprises a radial carcass extending between a pair of bead portions each including two bead cores therein and reinforcing a pair of sidewall portions and a tread portion, wherein the radial carcass is comprised of a rubberized ply of a continuous cord successively repeating round trip in at least one of the two bead cores as a pair between the pair of the bead portions along a circumference of the bead portion and a roundtrip return portion of the cord is existent in both the bead portions. In this case, at least one of the two bead cores has such a structure that one or more steel wires are arranged lengthwise and widthwise in radial and widthwise directions of the tire, and the cord of the carcass ply has a roundtrip return portion located through a side face of the bead core having the above structure so as to cover at least an innermost steel wire arrangement in the radial direction from an inner side in the radial direction of the tire.