is connected in crank mechanism like manner with a pivoted lever the end 51a 52a 53a 54a 55a and 56a of each pivoted lever 51 to 56 is fixed to the rotating disc 30 in the vicinity of its rotating edge 30a at 61 62 63 64 65 and 66 fig2 the in each case other pivoted lever end 51b 52b 53b 54b 55b and 56b is articulated at 71 72 73 74 75 and 76 to the anti skid arm 41 to 46 so that the latter and the pivoted levers 51 to 56 assume the position shown in fig1 with the anti skid arms in the swung in position if however rotating disc 30 is pivoted in the direction of arrow x1 fig3 anti skid arms 41 to 46 are swung out of casing 15 by means of pivoted levers 51 to 56 and assume the position shown in fig2 the swinging in and out of anti skid arms 41 to 46 is demonstrated in fig3 relative to anti skid arm 41 and the associated pivoted lever 51 in position a the anti skid arm and the pivoted lever assume a swung in position if the rotating disc 30 is rotated in the direction of arrow x1 the anti skid arm 41 is pivoted beyond position b into the swung out position c so that anti skid arm 41 comes to rest laterally alongside tyre 13 and by its free end 41b zonally engages over the tread 14 of tyre 13 fig7 and 8 in order to prevent in the case of a rotation of rotating disc 30 in direction x1 that the anti skid arms 41 to.