received by the International Bureau on 03 August 2018 (03.08.2018)

CLAIMS

1. An anti-skid device for automobile wheels with a bracket (3) separately mountable on the wheel disc (2) and a non-skid mechanism (4) with the bottom plate (16) attachable to the holder (3) and linked to the top plate (17) on the outside of which there are the arms (5) radially sliding and rotatable around their longitudinal axes, fitted at the ends with engagement surfaces (8), which abut, in the working position, against the circumferential surface of the tire (1) , characterized in that the arms (5) fitted in guides (9) are made up of two parts (7,6), where the upper part (7), rotatable with respect to the lower part (7), includes a sliding engagement surface (8) which is pushed by a spring (13) out of the upper part (7) provided with a cut-out (15) for a stop (14) linked to the engagement surface (8), the guide (9) being provided with a longitudinal groove (10) with a following helical groove (11) engaging with the guide element (12) linked to the upper part (7) of the arm (5), and the lower part (6) is connected to the toothed rack (22) of the transmission mechanism, where the toothed rack (22) engages with the pinion (21) mounted on the outer side of the top plate (17) coaxially with the wheel axis.

2. A non-skid device as per any claim 1, characterized in that an electric actuator (25) is arranged on the underside of the top plate (17), connected to the shaft of the pinion (21) through the bevel pinion (23) and the mating gear (24). 11

3. A non-skid device as per claim 1, characterized in that each pair of opposing toothed racks (22) is displaced vertically against the other opposing pairs.

4. A non-skid device as per claim 1, characterized in that a locking device is assigned to the transmission mechanism to block the positions of the retracted and extended arms (5) .

5. A non-skid device as per claim 4, characterized in that the locking device is assigned to the gear (24).

6. A non-skid device as per claim 5, characterized in that the locking device comprises an electric actuator (26) with a screw and nut transmission mechanism.

7 . A non-skid device as per claim 1, characterized in that the holder (3) is attached to the wheel by means of at least three bolts by which the wheel is mounted on the axle hub.

8. A non-skid device as per claim 1, characterized in that the bottom plate (16) of the anti-skid mechanism (4) is attached to the holder (3) by means of a bayonet joint (19) with a lock pin (20) .