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 radial force variation of a tire is corrected irrespectively of the kind of the organic fiber cord used, wherein a radial force variation (RFV) is measured at room temperature to specify a tire position indicating a minimum value of RFV, and an inner face of a tread portion is pushed and enlarged outward in a radial direction of the tire by a pushing means at a RFV bottom region sandwiching the position of the minimum RFV value from both sides thereof in a circumferential direction of the tread portion, and such a push enlarged state is kept for a given time.

Abstract: The invention provides an assembly of a pneumatic tire and a rim. The tire has at least one carcass ply 2 and a belt layer 8. The ply 2 is composed of ply cords and has end portions. The belt layer 8 is composed of belt cords provided outside of the ply 2. Each belt cord extends in a direction intersecting the ply cord. Each of the end portions is held in the rim 12. The width of the tire is maximum in a circumferential cross section “T” with a cylindrical shape with respect to the center axis “D” of the tire. The cross section “T” extends through the rim 10. When the tire is rolled under a load and a stress is applied on the tire as an arrow “X”, a neighboring portion 2d near the end portions 2a, 2b is considerably bending-deformed as arrows “Y” to absorb the stress. The roundness of the belt layer 8 is thus preserved to reduce the rolling resistance of the tire considerably.

Abstract: A radial force variation of a tire is corrected irrespectively of the kind of the organic fiber cord used, wherein a radial force variation (RFV) is measured at room temperature to specify a tire position indicating a minimum value of RFV, and an inner face of a tread portion is pushed and enlarged outward in a radial direction of the tire by a pushing means at a RFV bottom region sandwiching the position of the minimum RFV value from both sides thereof in a circumferential direction of the tread portion, and such a push enlarged state is kept for a given time.

Abstract: A pneumatic tire comprises a bead portion, a carcass wound around a bead core having a polygonal form from an inside of a tire toward an outside thereof in a radial direction and a bead filler arranged on an outer periphery of the bead core, wherein a reinforcing layer comprised of an organic fiber cord(s) or a metal wire(s) extended substantially in a circumferential direction of the tire is arranged in a position adjacent to the bead filler.

Abstract: A radial force variation of a tire is corrected irrespectively of the kind of the organic fiber cord used, wherein a radial force variation (RFV) is measured at room temperature to specify a tire position indicating a minimum value of RFV, and an inner face of a tread portion is pushed and enlarged outward in a radial direction of the tire by a pushing means at a RFV bottom region sandwiching the position of the minimum RFV value from both sides thereof in a circumferential direction of the tread portion, and such a push enlarged state is kept for a given time.

Abstract: Tire rubber material is highly accurately and efficiently extruded by a positive displacement extruding system that includes, as seen from an upstream side of the tire rubber, 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. While the tire rubber is caused to flow through the extruding system, the temperature of the rubber material is measured and controlled to be within a predetermined temperature range, in accordance with the measured temperature of the rubber material. The rubber material maintained at a controlled temperature is extruded from the extrusion nozzle, thereby improving the positive displacement performance of the extruding system.

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 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: An apparatus for producing a tire carcass having bead portions which are substantially free from cut surfaces of carcass cords. The apparatus includes a substantially toroidal carrier for supporting a rubber member of a tire. An indexing mechanism causes an indexing movement of the carrier by a predetermined angle about a rotational axis of the carrier. A feed mechanism continuously feed a carcass cord toward an outer surface of the carrier, wherein the feed mechanism are reciprocable in the axial direction of the carrier within a surface region thereof, that extends axially of the carrier at least between positions of the carrier corresponding to a bead portion and a tread end portion of a tire, respectively. Pressure mechanisms forming at least a pair are arranged adjacent to opposite ends of the surface region of the carrier, respectively, so that the carcass cord fed from the feed mechanism is wound about the respective pressure mechanisms and urged thereby toward the outer surface of the carrier.

Abstract: A pneumatic tire comprises a carcass made from at least one cord array comprised of many arch portions of a cord extending between a pair of bead portions in a meridional direction and arranged over a full circumference of the tire at an equal interval P in a circumferential direction of the tire and many circumferential portions of the cord alternately arranged in the bead portions, each connecting ends of adjacent arch portions to each other in the bead portion and extending substantially in the circumferential direction. In this case, the cord array is arranged at n layers (n is an integer of 2 or more) while offsetting these layers by a distance L obtained by dividing the interval P by n in the circumferential direction. Further, the bead wire reinforcing layer is arranged outward from the overlap region of the circumferential portions in the radial direction so as to sandwich the cord array from both sides 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 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 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: Method and apparatus for highly efficiently forming a tire reinforcing layer, such as a carcass ply or belt ply, either directly or indirectly on a rubber member which is supported on a rigid core having a toroidal shape. According to the invention, a continuous strip of reinforcing material comprised of a plurality of single cords or twisted cords is cut into reinforcing elements having a predetermined length. The reinforcing elements are successively fed to the rubber member from one side of the core, synchronously with an indexing movement of the core about its center axis. The reinforcing elements are then urged against the outer surface of the rubber member on the core along their longitudinal direction and thereby progressively pressure-joined to the rubber member.

Abstract: A pneumatic tire is highly precisely and efficiently manufactured by a method wherein, during formation of a green tire, at least one constitutive member, such as a sidewall (17), is formed by radially outwardly expanding a widthwise center portion of a substantially cylindrical carcass band (13), and subsequently winding an unvulcanized rubber strip and joining the rubber strip onto an outer peripheral surface of the expanded carcass band (13).

Abstract: Tire rubber material is highly accurately and efficiently extruded by a positive displacement extruding system that includes, as seen from an upstream side of the tire rubber, 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. While the tire rubber is caused to flow through the extruding system, the temperature of the rubber material is measured and controlled to be within a predetermined temperature range, in accordance with the measured temperature of the rubber material. The rubber material maintained at a controlled temperature is extruded from the extrusion nozzle, thereby improving the positive displacement performance of the extruding system.

Abstract: The invention provides an assembly of a pneumatic tire and a rim. The tire has at least one carcass ply 2 and a belt layer 8. The ply 2 is composed of ply cords and has end portions. The belt layer 8 is composed of belt cords provided outside of the ply 2. Each belt cord extends in a direction intersecting the ply cord. Each of the end portions is held in the rim 12. The width of the tire is maximum in a circumferential cross section “T” with a cylindrical shape with respect to the center axis “D” of the tire. The cross section “T” extends through the rim 10. When the tire is rolled under a load and a stress is applied on the tire as an arrow “X”, a neighboring portion 2d near the end portions 2a, 2b is considerably bending-deformed as arrows “Y” to absorb the stress. The roundness of the belt layer 8 is thus preserved to reduce the rolling resistance of the tire considerably.

Abstract: A rubber material for tire-constitutional member is laid on a rotating support at a high efficiency and a high accuracy by arranging a pair of rollers rotating in opposite directions in the vicinity of a radially outer surface portion of the support and utilizing a gap defined between the rollers as a roller die.

Abstract: Method and apparatus for highly efficiently forming a tire reinforcing layer on an outer peripheral surface of a rigid core (13), in which ribbon pieces (33) each comprised of parallel rubber-coated cords (17) are successively adhered to the outer peripheral surface of the core (13) in a circumferential direction thereof, with the side edges of the ribbon pieces in close contact with those of adjacent ribbon pieces. A plurality of cords (17) can be set by one adhering operation, thereby reducing the number of adhering operations in forming a tire reinforcing layer.