| 摘要 |
1302075 Moulding tyres GOODYEAR TIRE & RUBBER CO 25 June 1970 [12 Aug 1969] 30833/70 Heading B5A [Also in Division B7] In a method of making a pneumatic tyre having one or more radial plies such as 15, 16 of parallel cords, a tread portion 17, and a belt 13 of parallel cords, the tyre is cured in a mould 19, the tread having in cross-section at the central portion 20 thereof a depression, the maximum depth D of which lies between 0À013 centimetres and an amount, in centimetres, calculated from a given formula and which is dependent on the tread width, the belt strength, the ratio between the tyre width and depth, the modulus of elasticity of the belt cords and the angular orientation of the latter relative the mid-circumferential centre line of the tread. An equation is given relating the distance W of the tangent points 21 from the mid-circumferential centre line with the tread width, the depth D and the radius of curvature SR at the tyre shoulder, and a further equation relates the radius of curvature of the depression with the depth D and the distance W. |
