| 摘要 |
1375367 Making pneumatic tyres DUNLOP Ltd 4 May 1972 [15 May 1971] 15170/71 Heading B7C A bead for use in a pneumatic tyre and adapted to have a ply reinforced with steel cords turned round it is formed by providing a core 1 of coiled or strip metal, covering the core with unvulcanized rubber 2 having a plasticity of at least 80 lb. ft. at 140‹ C., cold pressing the bead to a circular shape, applying a zinc stearate in methylated spirits lubricant 4 thereto and wrapping the bead with textile fabric 5. After the tyre has been built and vulcanized the hardness of the rubber covering should be in the range 85 BS to 100 BS. The rubber is provided with a filler of low particle size silica. |
