| 摘要 |
PROBLEM TO BE SOLVED: To ensure required grip force with a simple structure.SOLUTION: A tire slip preventive system includes: a pulley device 16 having a shift pulley 14 and a shift mechanism 18; and a stud belt 20 installed to the shift pulley 14 and having at least one side surface which is anti-slip worked. The shift mechanism 18 is provided so as to rotatably support the shift pulley 14 and switch the shift pulley 14 between an actuating position for positioning the shift pulley 14 above an outer peripheral surface 12a of a tire 12, and a non-actuating position for positioning the shift pulley 14 to be shifted to a side part away from the upper side of the outer peripheral surface 12a of the tire 12. When the shift pulley 14 is switched from the non-actuating position to the actuating position, the stud belt 20 is stretched between the shift pulley 14 and the outer peripheral surface 12a of the tire 12. |
