| 摘要 |
<p>Pneumatic tyre has spikes which are arranged in the tread section and may be retracted below the contact surface of the section. Pref. the tyre wall is provided with peripherally spaced hoses which are associated with segments carrying the spikes, the segments being inflatable by the hoses. The hoses may be connected to an automatic pump whose piston is associated with a friction wheel through the intermediary of a linkage. The wheel is carried by the brake drum and arranged for engagement with a drive disc mounted axially slidably on the wheel shaft.</p> |
