| 摘要 |
A rotatable vehicle wheel has two oppositely facing axial sides and is provided at each of these sides with a mounting ring which is displaceable circumferentially with reference to the wheel. A tire is mounted on the wheel and provided on its circumferentially extending tread face with at least one groove extending across the tread face inclined to the circumference thereof. An elongated anti-skid band is partially and sliably received in the groove and has two spaced end portions each of which is connected with one of the rings, and longitudinally adjacent spiked and non-spiked tread surface portions located intermediate the end portions. A displacing arrangement can be actuated for causing stepwise longitudinal sliding travel of the band in the groove so as to either expose the spiked or the non-spiked tread surface portion of the band in this groove depending upon whether the non-skid properties of the band are to be utilized or not. At least one actuating element is connected with the mounting rings and rotates with the wheel, moving during such rotation in a predetermined path and being operable for effecting actuation of the displacing arrangement. Operator-controllable triggering means is provided and is movable between a rest position and an actuating position. In the latter it extends into the predetermined path of movement of the actuating element and in response to contact with the same triggers operation of the actuating element at least once during each revolution of the wheel. |
