Pneumatic tires having low aspect ratio
AssigneeDunlop Limited
InventorsAnthony Mark Mills, David Lyndon Buck
Life of this patent
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Abstract
A pneumatic tire, particularly a motorcycle tire, having an aspect ratio of less than 65% and a rounded tread profile, the bias angle of the tire carcass plies being less than 22.degree..
Claims36
A pneumatic tire having two bead regions, an aspect ratio of less than 65% and a rubber tread, having a profile rounded in cross-section, comprising a carcass of crossed plies extending from one bead region to the other and comprising cords which are placed in tension when the tire is inflated, the bias angle of each carcass ply being less than 22.degree. with respect to the mid-circumferential plane of the tire, the width of the tread measured in a direction parallel to the axis of the tire between the edges thereof being the maximum width of the tire measured in said direction, the tread rubber having a resilience measured on a Dunlop Healey Pendulum at 50.degree. C of the order of 50 to 55 and a hardness at room temperature of the order of 64.degree. to 66.degree. BS, and the tread rubber has the following composition:
- ______________________________________ Component Parts ______________________________________ Natural Rubber 50-70 LTP (styrene butadiene rubber containing 23.5% styrene) 50-30 Carbon Black 55-65 Extender Oil 7.5-12.5 Sulphur 1.75-2.25 ______________________________________
A pneumatic tire having two bead regions, an aspect ratio of less than 65% and a rubber tread, having a profile rounded in cross-section, comprising a carcass of crossed plies extending from one bead region to the other and comprising cords which are placed in tension when the tire is inflated, the bias angle of each carcass ply being less than 22.degree. with respect to the mid-circumferential plane of the tire, the width of the tread measured in a direction parallel to the axis of the tire between the edges thereof being the maximum width of the tire measured in said direction, the tread rubber having a resilience measured on a Dunlop Healey Pendulum at 50.degree. C of the order of 50 to 55 and a hardness at room temperature on the order of 64.degree. to 66.degree. BS and the tread rubber has the following composition:
- ______________________________________ Component Parts ______________________________________ Natural Rubber 50.0 LTP 50.0 Carbon Black 60.0 *Dutrex RT (Highly aromatic extender oil) 10.0 Zinc Oxide 5.0 Stearic Acid 1.0 *Nonox ZA (N-phenyl n-isopropyl paraffiniline diamine) 3.0 *Flectol H (Polytrimethyl dihydro quinniline) 2.0 Sulphur 2.0 *Vulcazit DZ (Dicyclo hexyl benthiozyl sulphena- mide) 1.0 PVI 50 (Cyclohexyl Thiophthali- mide) 0.5 184.5 ______________________________________ *Trademark
A pneumatic tire having two bead regions, an aspect ratio of less than 65% and a rubber tread, having a profile rounded in cross-section, comprising a carcass of crossed plies extending from one bead region to the other and comprising cords which are placed in tension when the tire is inflated, the bias angle of each carcass ply being less than 22.degree. with respect to the mid-circumferential plane of the tire, the width of the tread measured in a direction parallel to the axis of the tire between the edges thereof being the maximum width of the tire measured in said direction, the tread rubber having a resilience measured on a Dunlop Healey Pendulum at 50.degree. C of the order of 50 to 55 and a hardness at room temperature of the order of 64.degree. to 66.degree. BS, and the tread rubber has the following composition:
- ______________________________________ Component Parts ______________________________________ Natural Rubber 70.0 LTP 30.0 Carbon Black 60.0 *Dutrex RT 10.0 Zinc Oxide 5.0 Stearic Acid 1.0 *Nonox ZA 3.0 *Flectol H 2.0 Sulphur 2.0 *Vulcazit DZ 1.0 PVI 50 0.5 184.5 ______________________________________ *Trademark-
Dependencies are inferred from the claim text.