| 摘要 |
A pneumatic tyre and wheel rim assembly contains a support hoop 2 which supports the tyre if the latter deflates by contacting the inside of the tyre tread at top C and bottom A of the assembly as shown in Fig. 2. The dimensions of the hoop are such that its inner surface does not touch the rims whether the tyre is inflated or deflated, and its outer surface does not touch the tyre when inflated normally. Positioning means (not shown) which extend between the rim 5 and hoop 2 are provided to maintain the hoop in a position substantially concentric with the rim during running of the assembly with the tyre inflated, these means being made, e.g. of brittle foam plastics or an elastomer, so as to break up or deform if the tyre deflates thereby enabling the hoop to assume the Fig. 2 position. The hoop 2 may be made of steel or plastics or may be formed by a helical spring. <IMAGE> |
