Anti-slip device

Abstract

The present invention relates to an anti-skid device adapted to be mounted on the tire of a vehicle wheel, providing traction and improving the wheel's contact with the ground in snowy and icy conditions. The device comprises a central housing (2) from which three arms (3) project radially, which are extended at their outer ends by an anti-skid component (10) that transversely surrounds the tread of the tire. The anti-skid device has a locking mechanism, which consists of a locking element (24) with teeth that engage with teeth on the inner periphery of the housing (2). A handle (16) integrated in the hub (4) interacts with the locking element (24) to keep the device firmly locked when mounted on the wheel.

Description

[Technical field]

[0001] The present invention relates generally to an anti-skid device for use with vehicle wheels to improve traction on snow and ice. In particular, the present invention relates to an anti-skid device comprising an anti-skid element intended to be placed on the tread surface of a tire, having a plurality of arms, at least three, and actuation means allowing the arms to extend and retract. The actuation means are equipped with locking means that prevent the arms from extending when the anti-skid element is engaged. [Background technology]

[0002] A variety of anti-skid devices are available for attachment to vehicle tires to enhance traction under very severe snow and ice conditions. For many years, snow chains have been the standard, and although effective, they suffer from several disadvantages. Some of the disadvantages of such chains are that they are heavy, cumbersome, make noise when they contact exposed pavement or the inside of the fender, and require the automobile to be jacked up to attach them to the wheel. Faced with all these difficulties, motorists tend to leave the chains attached even on roads that are free of ice and snow, which accelerates the degree of wear on the chains. Additionally, these types of devices take up valuable space when not in use. To overcome the limitations of conventional snow chains, other types of anti-skid devices have been invented that are comprised of multiple arms extending radially from a central housing, each arm being connected to a hook-like anti-skid component that extends transversely over the tire tread.

[0003] An anti-skid device of the above type is disclosed in Norwegian published patent application 20191262 A1, in which an anti-skid device for enhancing traction on slippery roads is shown, in which three arms are held within a housing and arranged to extend from the housing. The ends of the arms have anti-skid elements that can be made to fit around a tire. The device has locking means to prevent the anti-skid elements from coming loose from the tire during use.

[0004] However, these locking means are difficult to operate and can come loose.Therefore, there is a need for a better way to lock the anti-slip elements during use.

[0005] Other examples of such devices are described in the following patents: (1) British Patent No. 2272193, (2) U.S. Patent No. 4209049, (3) U.S. Patent No. 4834158, (4) U.S. Patent No. 2873783, (5) U.S. Patent No. 4735248, (6) U.S. Patent No. 6053227, (7) European Patent No. 0110838, and (8) Korean Patent Publication No. 20040091223. Even if these anti-slip devices fulfill their intended purpose, they suffer from several drawbacks. They are complex, cumbersome, made of many parts, expensive to manufacture, difficult to install on the wheel, heavy, and take up space when not in use. Overall, they lack simplicity. It is therefore an object of the present invention to overcome many of the disadvantages of the prior art, as well as to present to the market an anti-slip device that is simple, effective and efficient, small, lightweight, and inexpensive to manufacture.

[0006] The present invention may also contribute to the formation of less airborne dust, which is a particular concern in standard studded tires used in winter, and instead encourages drivers to use the present invention and opt for studded tires that help overcome adverse icy conditions. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Norwegian Patent Publication No. 20191262 [Patent Document 2] British Patent No. 2272193 [Patent Document 3] U.S. Pat. No. 4,209,049 [Patent Document 4] U.S. Pat. No. 4,834,158 [Patent Document 5] U.S. Patent No. 2,873,783 [Patent Document 6] U.S. Pat. No. 4,735,248 [Patent Document 7] U.S. Patent No. 6,053,227 [Patent Document 8] European Patent No. 0110838 [Patent Document 9] Korean Patent Publication No. 2004-0091223 Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE PRESENT EMBODIMENT It is a primary object of the present invention to provide an anti-skid device that is easy to install and remove from a wheel without requiring skill, strength, or separate tools.

[0009] Another object of the present invention is to provide an anti-slip device that is simple, compact and made with few parts.

[0010] Another object of the present invention is to provide an anti-skid device that can be attached from the front of the wheel and can accommodate different wheel sizes.

[0011] Another object of the invention is to provide an anti-skid device that remains firmly anchored even if the wheel changes diameter due to flattening of the tire at the contact point between the wheel and the ground.

[0012] These and other objects are achieved by providing a device with a locking element that keeps the device firmly attached to the wheel during use. [Brief description of the drawings]

[0013] [Figure 1] FIG. 2 is a front view of the anti-slip device. [Diagram 2] FIG. 1 is an exploded view of the device with the wheel grip removed. [Figure 2b] 13A-13C show alternative embodiments of a locking element. [Diagram 3] FIG. 2 is a front view of the anti-slip device with the handles open. [Figure 4] FIG. 2 is a vertical cross-sectional view of the hub with the handle open. [Diagram 5] FIG. 1 is a vertical cross-sectional view of the hub with the handle closed. [Figure 6] FIG. 6 is a detailed view of FIG. [Figure 7] FIG. 1 shows a first embodiment of a wheel grip. [Figure 8] FIG. 2 shows a second embodiment of a wheel grip. [Figure 9] FIG. 9 is a side view of FIG. 8 with the cover components removed for clarity. [Figure 10] FIG. 13 shows an embodiment with a spring loaded button. [Figure 11] FIG. 13 shows an embodiment with a spring loaded button. [Figure 12] 13A-13C show embodiments of an auxiliary anti-slip element. [Figure 13] 13A-13C show embodiments of an auxiliary anti-slip element. [Figure 14] 13A-13C show embodiments of an auxiliary anti-slip element. [Figure 15] 13A-13C show embodiments of an auxiliary anti-slip element. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] With reference to Figure 1, an anti-slip device 1 according to the invention is shown. The device 1 consists of a housing 2 and three arms 3. Although three arms are shown in the figure, it should be understood that there can be four or more arms. The housing encloses the inner ends of the arms 3 and a mechanism for actuating the arms. A hub 4 is rotatable within the housing 2. This hub has a shaft 32 (see Figure 2) connected to a pinion that allows the arms to move outwards and inwards, respectively. These details are described more fully in the applicant's previous application, Norwegian Patent Publication No. 20191262, which does not form part of the present invention and will not be described further here.

[0015] At the outer end of each arm 3 there is an anti-slip element 10 (see figures 1, 7 to 9).

[0016] 2, the hub has a recess 15. A handle 16 has a hinge 17 at one end to allow the handle to fold into the recess 15. There is also an opening 18 through the hub. At the other (distal) end of the handle there is a means for interacting with a locking mechanism, which will be described in more detail below.

[0017] The handle folds into the recess when in the locked position. It also folds when not in use, for example during transport. The handle may include a release element 8 with a catch that can be activated to rotate the handle outwards. This is an added safety feature to avoid unintentional opening of the handle 16.

[0018] Located within the handle when not in use, crank 25 can be turned outwardly and is used to rotate hub 3 and actuate inward or outward movement of arm 3 via axis 32. Crank 25 is hinged to handle 16 at pivot base 25A which interacts with a locking mechanism as further described below.

[0019] The housing 3 has a circular recess 21 which receives the hub 4. The housing has an inner diameter slightly larger than the outer diameter of the hub 4, allowing the hub 4 to rotate within the housing 2 about an axis 32. The inner circumference of the housing 3 is provided with a number of projections or teeth 22.

[0020] The locking element 24 is held below and projects through the recess 18 of the hub 4. The locking element 24 is equipped with several projections or teeth 26 along its periphery, which can interact with corresponding teeth 22 of the housing 2. On the side 27 facing towards the user, a rib 28 projects outwardly and divides the facing side 27 into an upper and a lower region. While the locking element 24 is positioned between the hub 4 and the housing 2, the rib 28 penetrates the window 18, which makes it accessible to the user. In this way, the rib 28 acts as a sliding lever, allowing the user to manually bring the locking element 24 into contact with or out of contact with the ring teeth 22. With reference to Figures 2 and 2b, the locking element 24 and the teeth 26 are bevelled, so that they can more easily interlock with the corresponding teeth 22 on the housing. The number 26' in FIG. 2b indicates where the inclination occurs relative to the teeth 26 in the exploded view of FIG.

[0021] Additionally, the geometry of the interacting components is such that when the locking element 24 is in the open position, the handle 16 and crank 25 cannot be properly closed because the pivot base 25A of the crank would hit the rib 28 of the lock when the lock is in the open position. More specifically, to enable the additional safety features, the locking element 24 must be locked to allow the device to be closed.

[0022] When the handle 16 is opened outward, the locking element 24 is free to move.

[0023] In a preferred embodiment, either side or the two visible areas of rib 28 are color coded so that an operator can determine the state of the locking element. For example, the side closest to the center of the hub is colored green and the side away from the center is colored red. When the locking element is in either the locked or released position, only one of these colors will be visible, thereby clearly indicating the state of the device.

[0024] Figure 3 is a front view of the device in the operating position. The handle 16 is unfolded from the recess 15. The crank 25 is hinged at its end 25A to the handle and when turned outwards as shown in Figure 3, the crank 25 is used to turn the hub, which in turn actuates the arm. Figure 3 shows the locking element 24 engaged with the teeth 22 of the housing and with the rib 28 protruding through the window 18, i.e. in the locked position. Prior to actuation of the handle, the locking element 24 is disengaged, thus allowing the hub to be turned.

[0025] Figure 4 is a side view of the hub and housing shown in Figure 3. As can be seen, the locking element 24 has now been pushed out of engagement with the housing teeth 22, and the rib 28 is at the end of the recess 18 closest to the center of the device.

[0026] 5 is a side view of the hub showing the handle and crank folded back into the recess 15. In this locked position, the handle 25 and pivot axis 25A fit under the rib 28 on the locking element 24. The hub 4 is now fixed against rotation.

[0027] In figure 6, a detail of figure 5 is shown, showing the way in which the locking element 24 is held in a fixed position. A rib 28 protruding through the window 18 interacts with the end 25A of the crank 25. The crank 25 is pressed in so that its end 25A is under the rib 28. When the handle 16 is closed, the locking element is kept in contact with the teeth 22, i.e. in its locked position. The button 8 fixes the handle 16 to the hub 4, so that the handle 16 cannot be opened unintentionally during travel.

[0028] In addition to the teeth of the lock 2, an additional tooth 19 is integrated into the lower pivot end of the handle 16 near the hinge 17. This tooth will form an additional mechanical lock with the teeth 22 of the housing when the handle 16 is moved to the closed position.

[0029] The hub 4 may also be equipped with one or more flexible tooth elements 52 made of elastomer or rubber, as can be seen in FIG. 2. These will not overly hinder the rotation of the hub 4, but will provide a more pronounced feeling / click when the user rotates the handle to help engage / locate the teeth during locking. Additionally, these flexible tooth elements 52 may provide a damping function in case the whole system is positioned too tightly. That is, when the user starts to unlock the central hub 4, the arms 3 will immediately move outwards, which may result in an undesired reverse rotation. Such an unexpected movement may surprise the user, and the flexible tooth elements 52 may effectively damp such a movement.

[0030] The operation of the device is as follows: when not in use, the device is stored in the trunk of a car. When needed, the device is placed next to the wheel and the handle and crank are turned open. The crank can then be used to attach the device to the wheel, first by turning the hub counterclockwise, extending the arms 3 outwards. When placed around the tire, the crank 25 is turned in a clockwise direction to retract the arms 3 until the anti-skid element fits tightly around the rim of the wheel. When the operator is satisfied that the anti-skid element has fully engaged the tire, he or she will move the locking element 24 to engage the teeth 22. The locked state can be confirmed by observing the locking element face showing green. The user can then place the crank back into the handle, folding it into the recess. In this way, the anti-skid element is held in place. When the trip is completed, the same process is utilized in reverse.

[0031] Using the same procedure, attach a second device to the other drive wheel. Although not anticipated as needing to be used on all four wheels on a four-wheel drive vehicle, it may sometimes be necessary as some four-wheel drive vehicles regulate power to the drive axle that has less resistance.

[0032] With reference to FIG. 7, the anti-skid element 10 consists of a pad 40 equipped with a number of irregularly spaced raised studs 45, protruding from both the inner and outer surfaces, increasing friction with the ground and preventing any circumferential movement of the anti-skid component along the tire tread. The friction pad 40 is preferably made of a flexible rubber, for example TPU, i.e. thermoplastic polyurethane. The pad is held to a steel hoop wire structure 42 by including metal brackets 43 at the corners. The metal brackets advantageously include forward and rearward facing structures 43A, which engage the rubber tire when the weight of the vehicle is applied, i.e. when the pad is applied between the tire and the ground. The forward and rearward facing structures 43A prevent the pad from slipping on the tire (more clearly visible in FIG. 9). The studs 45 are preferably metal and have a wider area on each side, for example washers 44, which prevent the studs 45 from being pulled out / rotated in an undesirable way. The wire hoop 46 surrounds the pad and provides a pad assembly that is lightweight, resilient, and can be economically produced, and is preferably made of spring steel. The wire hoop 46 is preferably made of spring steel having a diameter of 5-8 mm.

[0033] FIG. 8 shows the underside of the anti-skid element 10. The hook / retaining portion 47 (shown in FIG. 8) is formed by a hoop 46, which holds the device 1 in the wheel by gripping the inner surface of the wheel, thereby preventing it from moving outward. The shape of the hoop in area 46A also adds additional spring / retraction capability to absorb some of the forces / deformations caused by the tire / car weight. The wire hoop is terminated by a bracket 48, which allows a sliding connection to the arm 3. The outward movement of the bracket 48, and thus the anti-skid element 10, is limited by the protrusion 3A at the end of the arm, thereby resulting in a firm connection between the anti-skid element 10 and the arm 3, but allowing the anti-skid element to be easily disconnected by the user by sliding them inward towards the hub 4. The flexure or spring element 49 is positioned to interact with the underside of the projection 3A to provide an inward spring force acting on the bracket 48 that maintains contact between the tire and the anti-skid element 10 even if the tire is locally depressed inwards, for example by running over a rock / kerb. This is detailed more clearly in the applicant's previous application, NO20191262. The pad 50 covers the inside of the bracket 48, thereby providing a wide surface for the wheel.

[0034] FIG. 9 shows the anti-skid element 10 with a partial cross-section through the metal bracket 48 to expose the interior. The ends 46B of the wire hoop 46 are held in two U-shaped channels 48A in the metal bracket 48, which fits onto the ends of the arms 3. This allows each wire end 46B to move linearly inwards and outwards, thereby ensuring that the anti-skid element 10 stays close to the tire surface during driving. The wire ends 46B are shaped so that they cannot move upwards / outwards. They then press downwards against the spring elements 51, which return the wires to their starting position once the tire has rotated further. The independent movement of the individual wire ends 46B is advantageous because it means that the car first drives over one end of the wires, and this movement only affects that end and does not try to rotate the entire anti-skid element 10 as it would if the wires were not held independently.

[0035] In this preferred embodiment, the studs 45 can take the form of protrusions, but also holes or localized areas formed from a material of high friction. The prevention of circumferential movement is further reinforced by the curved shape of the anti-skid element 40. An additional benefit of the curved shape is realized under braking conditions, since it mechanically engages the deformable rubber of the tire and does not rely only on the friction created by the gripping portion. This is important in that it reduces the forces applied to the arms 3 and the housing 2 during braking. Undesired outward movement of the anti-skid element 40 relative to the tire is prevented by the return portion 47, which covers the inner wall of the tire and prevents the device 1 from loosening from the tire. This is particularly appropriate when the high speed of wheel rotation, while turning the car from side to side, applies a combination of centrifugal and outward axial forces to the device 1, which must anchor it very firmly relative to the tire. In alternative embodiments, the return portion 47 may be replaced by one or more hook portions or hinged flange portions that can be locked in a downward position, thereby preventing outward movement of the anti-slip element 10. The anti-slip element 10 may be configured in other ways to perform the same function without departing from the spirit of the invention.

[0036] The anti-slip element 10 removably connects to the arm 3, where the bracket 4 allows a sliding connection, restricted at one end by a protrusion 3A at the distal end of the arm 3. When the anti-slip element 10 is connected to the arm 3, it slides freely along the length of the arm 3 up to the end section 3a. When the device 1 is assembled to the wheel, it is advantageous that the sliding connection between the element 10 and the arm 3 is restricted so that the element remains at the distal end of the arm 3. As depicted in Figures 10 and 11, a button 60 loaded with a spring 62 is present on the inside of the arm 3 and is located at a predetermined distance from the protrusion 3A. This prevents the anti-slip element from sliding inwards towards the hub during assembly when it is slid past the button 60 as indicated by the arrow 64. Advantageously, this button can be shaped to be automatically depressed when the user slides the bracket 48 along the arm 3 towards the protrusion 3A. The button 60 provides a stop once the bracket 48 has moved past the button 60. When the anti-skid device 1 is removed from the wheel and the anti-skid element 10 is disassembled from the arm 3 for removal and storage, the button must be pressed inwards so that the anti-skid element 10 moves along the arm 3 past the button.

[0037] When the anti-skid device 1 is fixed to the wheel of a vehicle, the area between the anti-skid elements 10 provides only the original tire surface for gripping on the surface. When the wheel rotates, it will lose the grip between the anti-skid elements 10. This can be a problem especially when braking to a stop, when only the tire is in contact with a slippery surface. Therefore, the present invention includes auxiliary anti-skid elements, which can be connected between the elements 10 when the anti-skid device is fixed to the wheel. Another advantage provided by the connection of the auxiliary anti-skid elements is that the force applied to a single arm 3 during braking is then distributed over the elements surrounding the tire surface.

[0038] Fig. 12 shows the anti-skid device 1 fixed to a wheel and a tire 71. The auxiliary anti-skid element 70 is similar to the element 10 with the pads 40 and the studs 45. A fastener 72 is used to connect the element 70 to the adjacent anti-skid element 10. The fastener 72 may be a metal hook, a wire and a spring element for fastening, similar to those used in conventional snow chains. Preferably, the fastener 72 allows for fastening, for example with an adjustable over-center mechanism, which creates a tight connection on either side between the element 70 and the element 10.

[0039] Fig. 13 shows another embodiment of an additional anti-skid element 75 in the form of a mat that covers only the exposed contact surface of the tire 71 and is also equipped with studs 45 similar to those used in the anti-skid element 10. The mat 75 can be made of one of several materials, for example a durable fabric equipped with metal studs. In the preferred embodiment shown in Fig. 13, the mat 75 can also be molded of a flexible, rubber-like material, for example TPU, or thermoplastic polyurethane. The studs 45 can be molded on the inner and outer surfaces of the mat 75 as required to improve grip and negate the need to insert many individual metal studs.

[0040] The anti-skid elements 70, 75 will have adjustable fastening means 73, 74 to adjust according to different wheel sizes and to securely fasten the anti-skid element 10 therearound. The elements 70, 75 can alternatively be provided in different sizes / lengths according to the wheel dimensions. The fastening means 73, 74 should preferably be flat so as to have as little effect as possible on the anti-skid properties of the mat 75. In this preferred embodiment, the fastening means 73, 74 comprise hook and loop connections, whereby the pad 74 with either hook or loop material (hook material in this embodiment) is permanently affixed by mechanical or chemical means to both ends of the mat 75. In this embodiment, the fastening means 73 comprises a flexible component equipped with hook or loop material (hook material in this embodiment) on its inner surface and arranged to engage with material 74 on the pad 75. The advantage of this system is that the hook or loop fastening means allows the user to attach the element 75 to the element 10 after the device 1 is loosely attached to the tire 71, and then tighten the fastening means 73 once the device 1 is subsequently tightened and firmly attached. Another advantage is that the fastening means 73, 74 are pressed together more firmly and tightly when the weight of the vehicle is applied to the fastening means 73, 74 as they pass between the wheel 71 and the road surface. If it is desired to make the thickness of the fastening means 73, 74 larger than necessary, it is possible to locally increase the thickness of the mat 75, making the outer parts of the mat 75 thicker than the areas where the fastening means 73 are located, thereby allowing a more uniform assembly thickness. In the embodiment shown, the mat 75 is equipped with pads 74 both on the inside and on the outside, allowing the greatest possible adjustment. The fastening means 73 may also be permanently attached to one or both ends of the mat 75, whereby the free end of the fastening means is folded back onto itself and the hook or loop material engages with matching material of the pad 74 on its inner surface.

[0041] It is then clear that in the preferred embodiment shown here, the fastening means 73 surrounds the cross section of the wire hoop 46, thereby connecting the element 75 to the non-slip element 10. In this embodiment, the friction pad 40 of the non-slip element 10 is equipped with a recess 40A, an area allowing the fastening means 72 to pass through the pad 40 and around the wire hoop 46. It should be noted that while the mat 75 is equipped with a single instance of fastening means 73, 74 at each end, the mat 75 can be equipped with several fastening means 73, 74 at each end, if necessary. In another preferred embodiment, the fastening means can be in the form of one or several chain segments attached to the ends of the mat 75, which chain segments are likewise equipped with hooks or catches for attachment to the non-slip element 10.

[0042] 14 and 15 disclose more detailed embodiments of the auxiliary anti-skid elements, designated 76 and 80. They can be fixed to and between the anti-skid elements 10. The anti-skid element 76 represents a chain type, which is connected to the outer part of the wire hoop 46 by hooks 77, which are interconnected by a flexible cable 78 or a partial spring and wire. The anti-skid element 80 consists of a pad, which covers only the contact surface of the tire. The anti-skid element 80 is made to be fixed by hooks 81 to and between the anti-skid elements 10 in the middle of its width. The entire pad 80 is made of a flexible material, such as rubber, and is accompanied by several studs 82. The hooks 77 and 81 include a locking mechanism, for example of carabiner type, to prevent unintentional removal, but are not shown.

Claims

1. A traction and anti-skid device (1) for wheel tires for limited emergency use with easy assembly use and storage, comprising a main body, a housing with protruding arms and a removable anti-skid element; A plurality of arms (3), at least three, are carried within the main housing (2) and project radially therefrom with means for mounting anti-slip elements (10); A hub (4) rotatable within said housing (2) is rotatable by a handle (16) while allowing said arm (3) to be extended or retracted; an operating means equipped with a locking means prevents the extension of the arms when the anti-skid element (10) engages the tread surface of the tire; wherein the anti-slip device (1) comprises: an anti-slip device (1) characterized in that there are locking means for the movement of the arm (3), consisting of a locking element (24) located between the hub (4) and the housing (2), the locking element being operable into a position in which its teeth (26) engage with a second set of teeth (22) located along the inner edge of the housing (2), while the arm (3) has means for limiting the movement of the anti-slip element (10) along the length of the arm (3) during assembly and mounting of the anti-slip element (10), the anti-slip element (10) being provided with auxiliary anti-slip elements (70, 75, 76 and 80) fixed to and between the main anti-slip element (10).

2. 2. The anti-slip device (1) according to claim 1, characterized in that the locking element (24) is movable between a first position in which the teeth (26) engage with the teeth (22) of the housing and a second position in which the teeth (26) are not in contact with the teeth (22).

3. 3. An anti-slip device (1) according to claim 2, characterized in that the teeth (26) of the locking element (24) are inclined so as to more easily interlock with the corresponding teeth (22) of the housing (21).

4. 3. The anti-slip device (1) according to claim 2, characterized in that the locking element (24) comprises a rib (28) protruding through a window (18) in the hub (4), while the hub (4) is rotated using a hinge (17), a handle (16) and a crank (25), the hinge (17) comprising teeth (19) arranged to interact with the teeth (22) of the housing (2).

5. 5. An anti-slip device (1) according to claim 4, characterized in that the handle (16) can be folded into a recess (15) in the hub (4).

6. 2. An anti-slip device (1) according to claim 1, characterized in that the anti-slip element (10) is equipped with a plurality of irregularly spaced studs (45) on the inner and outer faces.

7. The anti-slip device (1) according to claim 1, characterized in that the anti-slip element (10, 10') is held in a wire hoop (46) with an end (46B) that fits into a bracket (48) removably connected to the end of the arm (3), making the anti-slip element (10, 10') removable from the arm (3) for compact storage.

8. 2. The anti-slip device (1) according to claim 1, characterized in that the arm (3) has a spring-loaded stop and release button (60) to limit the movement of the anti-slip element (10) along the length of the arm (3).

9. 2. The anti-slip device (1) according to claim 1, characterized in that the auxiliary anti-slip elements (70, 75, 76 and 80) are available, which have means for fixing them to and between the anti-slip elements (10).

10. 2. The anti-skid device (1) according to claim 1, characterized in that the auxiliary anti-skid elements are provided in different sizes to fit various wheel sizes.

11. 2. The anti-slip device (1) according to claim 1, characterized in that the auxiliary anti-slip elements are made of a material such as durable fabric or rubber and are equipped with metallic studs.

12. 2. The anti-slip device (1) according to claim 1, characterized in that the auxiliary anti-slip elements are made of flexible strings, wires, chains and / or wire meshes.

13. 2. The anti-slip device (1) according to claim 1, characterized in that the auxiliary anti-slip elements (70, 75, 76 and 80) have adjustable means (72, 73, 74, 77, 78, 81) for anchoring them to the anti-slip element (10).

14. An anti-slip device (1) according to claim 13, characterised in that said adjustable means (73, 74) are made of hook and loop material.

15. Anti-slip device (1) according to claim 13, characterized in that the adjustable means (77, 78, 81) consist of hooks to which flexible means are attached.

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