| 摘要 |
PURPOSE:To automatically retract spike tire pins into a tire when operating on a non-frozen road so as to prevent both pulverization of the road surface and ensuing public nuisance, by placing the tire spike at the tip of a coil spring made of a shape storing alloy. CONSTITUTION:A container box 1 is formed in a concave section 3 of a spike tire 2 as an integrated unit and one end of a coil spring 5 is fixed to the bottom of the box 1 by means of a fixing member 6 while a spike tire pin 4 is placed at the other end. The coil spring 5 is made of a shape storing alloy and it is so constituted as to maintain its metalic composition by balancing its martensite shape changing temperature against the friction temperature between the tire and the non-frozen dry road surface. Upon contact with the frozen road surface, the tire is rapidly cooled aa well as the temperature of the coil spring 5 is lowered, extending the coil spring 5 to push the spike tire pin 4 out of the tire 2 surface and the tire 2 will act as a spike tire. |
