| 摘要 |
PURPOSE:To make selection from an ordinary tire to a spiked one and vice versa unrestrictable, by constituting the spiked tire so as to cause its inflation pressure to be raised up to the specified value in time of driving on a freezed, snow-covered road but to drop it down on a regular road. CONSTITUTION:A ground tire 4 in an ordinary steel radial structure is attached to an outer side rim 1 while an emergency spiked tire 5 to an inner side rim 2, respectively. And, in time of driving on a ferrzed, snow-covered road, the spiked tire 5 is filled up with air so as to cause its inflation pressure to be in a range of 2.0-7.0kg/cm<2>. With this pressure increase, the spiked tire 5 also is grounded together with the ordinary one 4 whereby a spiking function may be brought into full play. In time of driving on a road other than such freezed, snow-laden road, the inflation pressure in the spiked tire 5 is reduced down to 1.0kg/cm<2> or less. With this constitution, the spiked tire 5 is no longer grounded, bringing its spiking function to nothing. Thus, selection from the ordinary tire to the spiked one and vice versa is made to be unrestrictable, say, at will. |
