The invention refers to the anti-skid device for mounting on double-tyre wheels, in particular of those of lorries and trucks. The structure of the anti-skid device in question allows for simple mounting and fixing to the double-tyre wheels without any need to lift the vehicle or to remove the wheel. The invention has been classifie into class B 60 C 27/20 of the international Patent Classification.

The technical problem successfully solved by the proposed construction of the anti-skid device in question involves the construction of such device that will successfully prevent from skidding and lateral gliding on a slippery, snow-covered and/or frozen road, in particular of heavy lorries and trucks whereof the driving wheels usually consist of double tyres that do not allow for simple mounting of the traditional snow chains. In addition, the design of the anti-skid device in question allow for mounting to the double-tyre wheell even in the event when the vehicle has already got stuck in the snow and the usual snow chains cannot be of any use.

Skidding of the motor vehicle driving wheels and thereby the swerving or the incapacity to start the vehicle on a slippery, snow-covered and/or ice-covered road can be prevented by mounting snow chains or other similar devices that increase the friction between the tyre and the ground to the wheels.

The problem accompanying the use of standard snow chains and/or other devices providing for easier maneuvering and control of a heavy motor vehicle on a slippery road primarily lies in the fact that the driving wheels of such vehicles are provided with double tyres. As a rule, the snow chain can only be mounted on the outer of the two tyres of such driving wheels, which mostly does not provide sufficient friction for successful drive on a slippery road. In addition, mounting of snow chains may also be problematic in a dry area, in particular in bad weather conditions (snow, mud). To mount different types of snow chains it is first necessary to remove the snow or mud from the driving wheel, to clasp the wheel with the chain and to connect both ends of the chain on the inner side. It may be very hard to do for an unskillful driver; in addition, an incorrectly mounted chain may unclasp and damage the vehicle.

To sole the imposed technicai problem, it is, in addition to the traditional snow chains, possible to use special devices and/or assemblies that increase the friction between the tyre and the ground.

One of these devices is described in the document EP 252 050. The device consists of a special mechanism mounted on the axle close to the

wheel and can be approached or removed from the tyre. On the free end of this mechanism, there is mounted a small wheel with freely lying chain ends on the rim. When this wheel approaches the tyre of the rotating driving wheel, it also rotates and places the chain ends below the driving wheel tyre. This solution provides for efficient starting on a slippery road, although its main weak point lies in the fact that in deep snow or slush and/or mud on the road the mechanism for moving the small wheel with chain ends gets dirty and cannot approach the driving wheel tyre.

The anti-skid device for mounting on double-tyre wheels, such as referred to in this invention, solves the imposed technical problem in the way that it consists of a combination of rigid elements and of a traditional chain, flexibly connected and mounted in the way that they automatically get stuck between both driving wheel tyres, which also allows for automatic mounting of the anti-skid device to the driving wheel tyre of the vehicle.

The invention will be explained in detail on the concrete example and with the corresponding pictures, whereof : Figure 1 shows the view of a section of the anti-skid device referred to in this invention as the first example ; Figure 2 shows the view of a section of the anti-skid device referred to in this invention as the second example; Figure 3 shows the view of the anti-skid device referred to in this invention as the first example.

The anti-skid device for mounting on double-tyre wheels, such as referred to in this invention, is shown as example 1 in Figure 1. In fact it consists of several anti-skid elements 1 that are interconnected at equal distances and as such mounted on the rim of the double tyres of the wheel, whereby individual ends of the anti-skid elements are interconnected. The anti-skid elements 1 may be shaped as a rigid assembly of the element 1a that provides for interconnection of the anti- skid elements, e. g. oft he shorter attachment, sleeve, etc., while the transversal elements 1b may be shaped as a round or square rod etc.

Elements 1a are interconnected with a linking agent 2 that may be a chain, a wire etc. providing for flexible interconnection of anti-skid elements. The free ends of anti-skid elements 1 are interconnected with the linking agent 3 on one end and with the linking agent 3'on the other end. The linking agents 3 and 3'may also consist of a chain, a wire and the like, providing for flexible interconnection of anti-skid elements 1.

At the beginning and/or at the end of the linking agents 2,3 and 3' there may be mounted special guides that get stuck between both tyres in the way to provide also for automatic mounting of the anti-skid device referred to in this invention.

At mounting of the anti-skid device referred to in this invention it is important that the linking agent 2 is mounted in the way to get stuck between the two tyres of the driving wheel on which the device is to be

mounted. Once mounted, the anti-skid device assumes the position shown in Figure 3.

To secure efficient operation of the device referred to in this invention, the elements 1 b are of such size that they extend over both tyres.

The anti-skid device for mounting on double-tyre wheels, such as referred to in this invention as the second example, is shown in Figure 2.

In this concrete example the anti-skid device consists of several anti-skid elements 1'that are interconnected at equal distances and as such mounted on the rim of the double tyres of the wheel. The anti-skid elements 1'may be shaped as a rigid assembly of the element 1a'that provides for interconnection of the anti-skid elements, e. g. the attachment, sleeve etc., while the transversal elements 1 b'may be shaped as a round or square rod and the like. The elements 1a'are interconnected with the linking agent 2'that may be a chain, a wire and the like, providing for flexible interconnection of anti-skid elements.

For appropriate and efficient introduction of the linking agent 2'in between both tyres the elements 1 a'are longer than in the first example.

Practical experiments have shown that both examples of the anti-skid device referred to in this invention successfully solve the imposed technical problem of skidding and lateral gliding on a slippery, snow- covered and/or ice-covered road, in particular in case of heavy trucks and lorries with two tyres on the driving wheel, and allow for simple mounting of the anti-skid device.

Besides, the design characteristics of both examples of the anti-skid device allow for adjustment of both versions to the actual situation on the road, depending on the load of individual pair of wheels and/or on different holes and rocks on the road.