Adaptor disk for attaching an anti-skid device to a wheel disk or rim

In an anti-skid device, particularly for motor vehicle wheels with pneumatic tires for driving on ice and snow, which comprises a fixing disk which can be fastened to the wheel disk or rim and which is provided with openings for fastening to the rim screw or wheel studs;

• and a supporting disk, held on a shaped-on hub of the fixing disk and lockable by means of a retaining ring, and having a plurality of equidistantly spaced, radially disposed anti-skid arms, each formed with a pre-bent profile from a resilient elastic material, which engage over the tire tread and are provided externally and internally on their free ends with a gripping profile and externally having spikes or metal bodies;
• wherein the improvement comprises an adaptor disk carried on a side of the fixing disk remote from the supporting disk, said adaptor disc being connected by screw connections to the fixing disk and having a plurality of radially directed elongated holes provided on at least two circular lines around the adaptor disk center having different diameters and including four equidistance holes on the circular line adjacent the center of the adaptor disk, and six holes on the outer circular line at equal and unequal distances from one another, the six holes on the outer circular line including a first group of three elongated holes formed equidistantly in the adaptor disk, the spacing of, in each case, two of these elongated holes in the first group being approximately 120.degree. and a first of the three elongated holes in the first group being at a distance of approximately 75.degree. from an axis passing through the center of the adaptor disc, and in a second group of three elongated holes, a first elongated hole is at a distance of approximately 45.degree. from the axis and two other elongated holes are arranged counterclockwise at distances of approximately 90.degree. from each other in the adaptor disk, the adaptor disk further including four or five equidistantly arranged threaded fixing disk fastening screw reception bores located on a third circular line.