Abstract:
Provided is a run flat tire having an enhanced ride comfort in running on general road surfaces and an enhanced driving stability on snowy road surfaces at the time when the tire is not punctured, as well as an enhanced maneuverability, particularly starting ability, on icy road surfaces in run-flat running where the tire is punctured. Three belt layers (8, 9, 10) are disposed on an outer circumferential side of a carcass layer (6) in a tread portion (4). In addition, as to the three belt layers, the cord angle α of the innermost belt layer (8) with respect to a circumferential direction of the tire is set at 15° to 30°, the cord angle β of the intermediate belt layer (9) with respect to the circumferential direction of the tire is set at not less than 40°, and the cord angle γ of the outermost belt layer (10) with respect to the circumferential direction of the tire is set at 35° to 70°.
Abstract:
Disclosed is a pneumatic tire which is allowed to increase block stiffness not only during braking and driving but also during cornering, and is allowed thereby to compatibly enhance tire performances both during braking and driving and during cornering. The pneumatic tire of the present invention is one where a plurality of longitudinal grooves extending in a tire circumferential direction and a plurality of lateral grooves extending in a tire widthwise direction are provided in a tread portion, a plurality of blocks are defined by these longitudinal and lateral grooves, and a plurality of sipes extending in the tire widthwise direction are provided to each of the blocks, wherein, with regard to each of the sipes, a zigzag shape is formed on a tread surface, bent portions ranging in the tire widthwise direction while bent in the tire circumferential direction are formed inside the block at at least two positions in the tire radial direction, and a zigzag shape with an amplitude in the tire radial direction is formed in each of the bent portions.
Abstract:
Provided are a pneumatic tire with a durability which is improved by preventing oxygen deterioration of coating rubber of a reinforcement layer, and a method of manufacturing the pneumatic tire. The pneumatic tire according to the present invention is a pneumatic tire including a reinforcement layer having reinforcement cords. In the pneumatic tire, the reinforcement layer is covered with thin films each made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending a thermoplastic resin with an elastomer in a way that the reinforcement is wrapped with the thin films. A method of manufacturing the pneumatic tire includes: arranging a thin film made of a thermoplastic resin or a thermoplastic elastomer composition on an outer periphery of a making drum, the thermoplastic elastomer composition being obtained by blending a thermoplastic resin with an elastomer; arranging a reinforcement layer including reinforcement cords on an outer periphery of the thin film; arranging another thin film on an outer periphery of the reinforcement layer; covering the reinforcement layer with these thin films in a way that the reinforcement layer is wrapped with the thin films; making an uncured tire including the reinforcement layer; and curing the uncured tire.
Abstract:
A pneumatic tire for use on iced and snowed road surfaces has a tread surface. The tread surface has a plurality of main grooves extending in a circumferential direction of the tire and a plurality of lateral grooves extending in a width direction of the tire. Blocks are defined by the main grooves and the lateral grooves. The blocks have a ground contact face which has a plurality of pairs of sipes comprising a left sipe and a right sipe extending in the tire width direction. The plurality of pairs of sipes are placed in a predetermined interval in the tire circumferential direction. Each of the left and right sipes of each pair extends from a width-directional center portion of the ground contact face of the block toward each way of the tire width direction so as to open its outer end to each side face of the block.
Abstract:
A pneumatic radial tire has a tread pattern having a pair of straight main grooves each having a width equal to 8-13 percent of a ground contact width W of the tire and extending in parallel on opposite sides of an equator of the tire, a plurality of lug grooves extending across shoulder regions formed on the outersides of the pair of main grooves from the pair of main grooves outwardly toward the ends of the ground contact surface of the tire to form in cooperation with the main grooves successive rows of blocks, and a plurality of V-shaped sub-grooves in the shoulder regions spaced at a predetermined pitch apart in the circumferential direction of the tire and extending divergently with respect to the direction of reverse rotation of the tire, wherein the ratio of a distance W1 between respective centers of the main grooves to the ground contact width W is in the range of 0.2.ltoreq.W1/W.ltoreq.0.4; an angle .alpha. of inclination of the lug grooves with respect to the circumferential direction of the tire as viewed from the reverse tire rotating direction is in the range of 90.degree.-130.degree.; and an angle .beta. defined by the V-shaped sub-grooves is in the range of 15.degree.-35.degree..
Abstract:
A pneumatic tire improved in on-ice performance and on-snow performance in good balance. The pneumatic tire includes a tread portion extending in a tire circumferential direction and forming a ring shape, a pair of sidewall portions on both sides of the tread portion, respectively, and a pair of bead portions on inner sides of the sidewall portions in a tire radial direction, respectively. The tread portion includes a plurality of longitudinal grooves extending in the tire circumferential direction and a plurality of lateral grooves extending in a tire width direction. The longitudinal and lateral grooves define a plurality of block rows each including a plurality of blocks. Each of the plurality of blocks included in at least one of the block rows includes at least three closed grooves including at least one first closed groove and at least one second closed groove.
Abstract:
Provided are a pneumatic tire with a durability which is improved by preventing oxygen deterioration of coating rubber of a reinforcement layer, and a method of manufacturing the pneumatic tire. The pneumatic tire according to the present invention is a pneumatic tire including a reinforcement layer having reinforcement cords. In the pneumatic tire, the reinforcement layer is covered with thin films each made of a thermoplastic resin or a thermoplastic elastomer composition obtained by blending a thermoplastic resin with an elastomer in a way that the reinforcement is wrapped with the thin films. A method of manufacturing the pneumatic tire includes: arranging a thin film made of a thermoplastic resin or a thermoplastic elastomer composition on an outer periphery of a making drum, the thermoplastic elastomer composition being obtained by blending a thermoplastic resin with an elastomer; arranging a reinforcement layer including reinforcement cords on an outer periphery of the thin film; arranging another thin film on an outer periphery of the reinforcement layer; covering the reinforcement layer with these thin films in a way that the reinforcement layer is wrapped with the thin films; making an uncured tire including the reinforcement layer; and curing the uncured tire.
Abstract:
There is provided a pneumatic tire capable of improving on-snow performance on a snowy road surface including a sherbet-like snowy road surface without deteriorating on-ice performance. An assistant groove 6 less in width than the main grooves 2 extends in the circumferential direction TC of the tire in each middle land 4. The lateral grooves 7 include right and left first lateral grooves 8 extending from the center land 3 outward in the widthwise direction of the tire beyond the tire ground contact ends TF, and right and left second lateral grooves 9 extending from the middle lands 4 outward in the widthwise direction of the tire beyond the tire ground contact ends TF, the first lateral grooves 8 and second lateral grooves 9 being alternately disposed in the circumferential direction TC of the tire. The groove area percentage in the center region portion 1C of the tread surface 1 is less than the groove area percentage in the ground contact surface region G of the tread surface 1.
Abstract:
There is provided a pneumatic tire capable of improving on-snow performance on a snowy road surface including a sherbet-like snowy road surface without deteriorating on-ice performance.An assistant groove 6 less in width than the main grooves 2 extends in the circumferential direction TC of the tire in each middle land 4. The lateral grooves 7 include right and left first lateral grooves 8 extending from the center land 3 outward in the widthwise direction of the tire beyond the tire ground contact ends TF, and right and left second lateral grooves 9 extending from the middle lands 4 outward in the widthwise direction of the tire beyond the tire ground contact ends TF, the first lateral grooves 8 and second lateral grooves 9 being alternately disposed in the circumferential direction TC of the tire. The groove area percentage in the center region portion 1C of the tread surface 1 is less than the groove area percentage in the ground contact surface region G of the tread surface 1.
Abstract:
A pneumatic tire for ice-bound or snow-covered roads, which has fine grooves formed in a tread surface, thereby improving brake and drive performance on ice-bound roads in early periods of wear. This pneumatic tire for ice-bound or snow-covered roads has its tread partitioned into a plurality of lands, these lands being formed with sipes, wherein the tread surface at the lands is formed with a plurality of fine grooves shallower than the sipes, the edges of these fine grooves being curved. Further, the width of the openings of the fine grooves is larger than the width of the bottoms thereof. Further, the angle of the fine grooves with the circumferential direction of the tire is 42 to 60 degrees.