Abstract: A porous film is here disclosed which is obtainable by stretching a film in at least uniaxial direction, said film being formed from a resin composition containing 25 to 70 parts by weight of a polyolefin resin and 75 to 30 parts by weight of an inorganic filler; said resin composition further containing 0.5 to 10 parts by weight of dehydrated castor oil (a) and 0.01 to 5 parts by weight of hardened castor oil (b) based on the total 100 parts by weight of the polyolefin resin and the inorganic filler; and the amount of the component (a) being 20 to 95% by weight based on the total amount of the components (a) and (b). In this porous film, softness and feeling like cloth, moisture vapor transmission, uniformity of the film thickness and the like are equal to their conventional levels. Furthermore, the adhesive strength of a securing tape does not deteriorate because the third components (a) and (b) do not float on the surface of the porous film.

Abstract: A pneumatic radial tire comprises a radial carcass ply wound around the axis of the tire over one turn so that the terminal edge of the winding of the carcass ply overlaps with the starting edge thereof to define an overlap-joint part, the overlap-joint part provided in one of the starting edge and terminal edge with at least one cut by which carcass cords existing therein are cut, and a method of making the same comprises the steps of cutting the starting edge prior to winding a carcass strip or cutting the terminal edge prior to the end of winding a carcass strip.

Abstract: A pneumatic radial tire comprises a radial carcass ply wound around the axis of the tire over one turn so that the terminal edge of the winding of the carcass ply overlaps with the starting edge thereof to define an overlap-joint part, the overlap-joint part provided in one of the starting edge and terminal edge with at least one cut by which carcass cords existing therein are cut, and a method of making the same comprises the steps of cutting the starting edge prior to winding a carcass strip or cutting the terminal edge prior to the end of winding a carcass strip.

Abstract: A pneumatic tire comprises: a carcass extending between bead portions of the tire; a belt reinforcement layer disposed radially outside the carcass and including at least one cord ply extending between tread edge portions to reinforce a substantially full width of the tread portion; and a cord layer disposed radially outside the belt reinforcement layer and having a width narrower than that of the belt reinforcement layer, wherein the cord layer is disposed beneath a rib defined between circumferentially extending grooves to reinforce the rib, or the cord layer is disposed asymmetrically with respect to the tire equator to provide a asymmetrical reinforcement for the tread.

Abstract: A pneumatic tire which comprises a belt disposed radially outside a carcass and inside a tread and having opposite axial edges, the belt comprising a cord continuously wound around the carcass while running zigzag between the edges of the belt to defining cord segments extending between the edges of the belt, the cord segments including first cord segments and second cord segments, the first cord segments laid substantially parallel with each other, and the second cord segments laid substantially parallel with each other and crosswise to the first cord segments.

Abstract: An improved method for pressure-adhering tire building component material is provided which includes the steps of:(1) adhering sidewalls to a first cover;(2) cutting each of the sidewalls at a given portion thereof;(3) provisionally securing a joint portion defined by the cut ends of each of the sidewalls;(4) enfolding a bead portion with a bead edge of the sidewall and entirely pressure-adhering each sidewall to the first cover; and(5) pressure-adhering the joint portion provisionally secured with a machine,wherein the step (5) is carried out separately from a production line in which the steps (1) to (4) are carried out.

Abstract: A pneumatic tire has a carcass composed of at least one carcass ply extending from a tread part through sidewall parts and turned up around a bead core in each of two bead parts. The carcass ply comprises a plurality of ply strips which are continuously arranged in the tire circumferential direction with overlapping portions, wherein one end in the tire circumferential direction of one ply strip overlaps to an outer surface of an adjacent ply strip adjacently arranged on one end side, and the other end in the tire circumferential direction of the one ply strip overlaps to an inner surface of an adjacent ply strip adjacently arranged on other end side.

Abstract: An apparatus for pressure-adhering a joint portion of a tire building component material comprising: a vertically movable table for placing thereon a first cover with its axis oriented vertically and in a state where a joint portion of the component material is provisionally secured; and a vertically movable roller assembly having a device for fixing the first cover, rollers for compressing the first cover from the inside and outside of the first cover, and an impeller device for causing the rollers to move vertically.

Abstract: A pneumatic tire has a carcass composed of at least one carcass ply extending from a tread part through sidewall parts and turned up around a bead core in each of two bead parts. The carcass ply comprises a plurality of ply strips which are continuously arranged in the tire circumferential direction with overlapping portions, wherein one end in the tire circumferential direction of one ply strip overlaps to an outer surface of an adjacent ply strip adjacently arranged on one end side, and the other end in the tire circumferential direction of the one ply strip overlaps to an inner surface of an adjacent ply strip adjacently arranged on other end side.

Abstract: A method for fabricating a rubberized wire sheet passes a plurality of wires through an extruder to coat each of the plurality of wires with rubber to form rubberized wires, and passes the plurality of rubberized wires through a calender roller system to form them into the rubberized wire sheet having a desired width. The rubberized wires may be further coated with rubber when calendered in the calender roller system. This method demonstrates an improvement in rubber impregnatability, topping accuracy, processability, and quality.

Abstract: A pneumatic tire having an improved bead construction in which each of the bead cores which is composed of a number of layers of bead wires piled up one upon another to have a hexagonal cross section, whose one side is approximately parallel to a bead base portion, has at least more than one layer of bead wires further piled up on the top of the number of layers at a side opposite to the one side of the hexagonal cross section to fill up a gap or clearance between the side opposite to said one side of the hexagonal cross section and a bias-ply carcass turned up around the bead cores.