IE43122B1 - Anti-skid device for vehicle tyres - Google Patents

Description

This invention relates to an antiskid device for vehicle tyres and particularly to an improved structure having a mesh or-network to cover the tread and at least part of each of the tyre sidewalls.

Numerous types of antiskid devices for the driving wheels of vehicles are know, particularly in the form of snow chains. Various constructions of these chains are employed depending upon the primary function, which they are to fulfill. If good steering and adequate grip are required, steering being the primary consideration, then such snow chains are produced with rows of chain links extending circularly with respect to the tyre, each link being approximately parallel to a tangent line to the tyre. If, however, traction is the primary requirement, then the chains are more frequently constructed with the rows of links extending transversely, approximately parallel to the tyre axis. Generally speaking, presently known chain constructions are not constructed in a manner which ensures both good steering and a completely satisfactory traction characteristic.

As is well known, particular difficulty is encountered in mounting the chain assembly on the vehicle wheels. Here again, a wide variety of construction techniques have been employed, but all present the disadvantage of requiring considerable time and effort in fitting the chains to the tyres. Furthermore, because of the difficulty in mounting them on the tyres, particularly in the open under adverse weather conditions, chains are simply frequently not used at all.

This is particularly true because of the fact that when mounting the chains,at least the side chains which are arranged on either side of the tyre tread and form the lateral limit of the snow chain must be opened - 2 43122 or detached at at least one point. Then, when the chain has been loosely applied to the tyre, the opened portions of the chain must be closed and tightened so that the chain does not create noise when the vehicle is travelling. It is generally necessary after fitting the snow chain to the tyre to travel a certain distance, after which the chain must be retightened.

It is also known to provide traction devices resembling netting in an effort to overcome the disadvantages of chain structures. However, such netting or meshwork structures have not been sufficiently durable and have not significantly improved the traction and steering characteristics provided by chains, and therefore have not received wide acceptance.

According to the present invention there is provided an antiskid device,for use on a vehicle tyre, which comprises an endless belt formed of a mesh or network adapted when placed on the tyre to cover the tread and at least part of each of the sidewalls of the tyre, which belt is bounded on each side by an end ring, wherein:(a) the meshes of the mesh or network are made of flexible substantially nonextensible continuous rope- or wire-like material and each mesh adjacent the tyre tread, when the device is fitted on a vehicle tyre, is of greater dimension in a direction parallel to the direction of movement of the tyre than in a direction transverse thereto; (b) at least one of the end rings is capable of being extended to enable the device to be mounted on the tyre; and (c) all meshes adjacent the end rings are connected to the respective end rings. - 3 63122 Such an antiskid device can be made inexpensively and can simply and easily be fitted on a mounted vehicle wheel; when mounted, it does not require reduction of travelling speed and does not impair either the antiskidding action or the steering action of the vehicle. i The invention is illustrated by way of example, with reference to certain particularly advantageous embodiments thereof, which are now described with reference to the accompanying drawings, wherein :Figure 1 is a partial plan view of a device according to the s invention in' unrolled relaxed condition, i.e. not fitted to a tyre; Figure 2 is a partial side elevation of a vehicle tyre showing schematically an antiskid device according to the present invention mounted thereon; Figure 3 is an enlarged partial view of part of Figure 1; Figure 4 is an enlarged plan view of a connection element usable in the device of Figures 1-3; Figure 5 is a section along lines V-V of Figure 4; Figure 6 is a schematic representation of a portion of an antiskid device according to the invention before application to a tyre; Figures 7 and 8 are vertical sections through a connection element usable in the device of Figure 6; Figures 9 and 10 are vertical sections through further embodiments of connection elements usable in the device of the present invention; Figure 11 is a section along the lines VI-VI in Figure 10; Figures 12 and 13 are vertical sections through two additional - 4 43122 types of connection elements which may be used; and Figure 14 is a partial plan view of a further embodiment of the invention showing one end ring in detail.

As will be seen, the invention is based on the consideration that protection against skidding is obtained if the tyre tread is covered with a relatively coarse mesh or network tensioned over the tread. In the present invention, the meshes overlying the tread are of larger dimension in the direction tangential to the tyre periphery than transverse thereto; at the same time, the mesh or network is expandable laterally but substantially nonexpendable circularly. The device of the present invention can be constructed with a minimum of parts which need to be opened or detached and subsequently closed or attached again after mounting the device on the tyre. Thus, the end rings may simply be formed of a material having sufficient elasticity to permit them to be easily fitted over the largest tyre periphery for which the device is designed. Since the device can be laterally telescoped or collapsed by means of the combination of the two elements the end ring members on the one hand and the endless belt on the other the antiskid device of the invention can easily be fitted on the tyre.

It is not important, in this connection, if the belt is initially only partly fitted on the tyre and the final fitting thereto only takes place after rotating the wheel. As both of the ring members and the belt are endless closed loops, in use, even if only partially fitted, the antiskid device cannot fall from the tyre.

Referring now to Figure 1, it will be seen that the antiskid device comprises a mesh or network belt 1 with rhombic meshes 2 formed by a plurality of interconnected wires so that each of the meshes has a - 5 43123 dimension in the circular or tangential direction of the tyre, which is significantly greater than the dimension transverse with respect to the tyre. The direction which is referred to herein as circular or tangential is indicated by the double arrow 3 and the transverse direction is indicated in Figure 1 by double arrow 4, arrow 4 being essentially parallel to the axis of rotation of the vehicle wheel. In the embodiment shown in Figure 1, the ratio of the dimension of the meshes which will overlie the tyre tread in the direction of arrow 3 to their dimension in the direction of arrow 4 is approximately 2:1. While this ratio need not be exact and can be varied, the important point is that the dimension in direction 3 be larger than in direction 4 when the mesh or network is adjacent to the tyre tread. The condition that the mesh dimension be greater peripherally than transversely does not apply to the row of meshes adjacent the end rings 5. j At the lateral limits of the belt 1, at positions which would be along the sidewalls of the tyre when the device is mounted on a tyre, there are elastic end rings 5 constructed as closed ring members. The outermost wires forming the meshes 6 are fixed to the rings 5 at a plurality of spaced positions. As a result, the belt 1 is given a specific curvature which facilitates the mounting of the antiskid device on the tyre. Figure 3 shows in more detail an embodiment of the belt 1* constructed from individual wire rings 7, 8, 9 and 10. In order to produce belt l\ the individual wire rings 7-10 are alternately connected at uniformly circularly spaced apart points with adjacent rings by means of connection elements 11. The points of connection are alternately circularly offset, resulting in a network with meshes 2 of the type shown ih Figures 1 and 2. - 6 4 312 2 The connection elements 11 can be constructed in various ways, e.g. as a clamp formed to encircle the wires of adjacent wire rings clamping these wires firmly together.,or by soldering or welding the connection points. An appropriate connection method must be selected for connecting the wire rings 7-10 to end rings 5, depending upon the material and construction used for these rings. If the end rings and the wire rings are made of wire coated with rubber, they can be connected together by vulcanisation.

Figures 4 and 5 illustrate a specific connection element including a shaped member 12 which has bores 13 and 14 through which are placed wire rings 15 and 16. The wire rings 15 and 16 are clamped in member 12 in an immovable fashion. It is also possible to have slots in place of bores 13 and 14.

As can be seen from Figures 4 and 5, member 12 can also carry additional antiskid means, such as a protrusion in the nature of a spike 17 fixedly mounted in member 12. Because of the fact that the device is so easily mounted and dismounted on the tyre, the disadvantages of the well known studded tyre are substantially avoided because the tendency is to employthe antiskid device only when absolutely necessary.

Figure 6 shows a further embodiment of an antiskid device according to the invention. In Figure 6 there is shown a belt 1 in its relaxed state before being applied to a tyre, the meshes in Figure 6 being rectangular in this relaxed state. When the apparatus is fitted to a tyre, the meshes expand transversely to a rhombic shape. It will be observed that the meshes 2 have a considerably larger dimension in the direction of arrow 3 than in the transverse direction (arrow 4),even when the antiskid device is applied to the tyre, i.e. particularly on the 3132 tyre tread periphery. It will be observed that one end ring 5 in the device of Figure 6 must be expandable, either elastically or in some other fashion to allow the device to be fitted on the tyre. The other ring may also be, e.g. elastically, expandable, but it need not be as expandable as the inner ring and can, in fact, be practically not stretchable or expandable at all.

The edge meshes 6, those adjacent the end rings 5, are connected to the end rings in the embodiment of Figure 6 by connecting members 20. Members 20 can be constructed in various ways and can, for example, be metal clips. Alternatively, connecting members 20 can be replaced by connections resulting from vulcanisation, welding or the application of an adhesive.

Meshes 2 and 6 of the antiskid device shown in Figure 6 are formed by rope- or wire-like material 7 whereby in each case two i juxtaposed cords or strings 7 are inter-connected by connection elements. These connection elements and members 20 can be produced in various ways, for example, from an elastomer or from a steel strip. .The elements must perform the function of interconnecting}in forcing locking manner^ adjacent sections of the rope- or wire-like material. Depending on the particular production technique used to assemble the device, these sections can be immediately adjacent each other or can be spaced apart from one another at the connection point by a relatively small distance. This is shown in Figure 6 in an exaggerated manner.

The use of the rope- or wire-like material used for the mesh or network,which is flexible but substantially inextensible and which preferably comprises metal or textile fibres or cords, means that the antiskid device can be deformed e.g. to a narrow strip when fitting the - 8 43122 device to the tyre and then deformed to a wide, mesh or network engaging the tyre and extending over the width of the tyre.

Figures 7 and 8 show a shaped connection element 21, in section, this element being formed from a steel clip 22 with a rubber member 23 vulcanised or otherwise adhered’ to one side of the clip. Clip 22 is provided with two cavities 25 which are separated by a spacing member 24, the cavities serving to receive two adjacent sections of rope- or wire-like material 7, which as shown in Figure 8, are firmly connected to element 21 by deforming the ends of the clip partially to surround and engage the sections. The rope- or wire-like material 7 shown in Fugure 8 is, for example, formed from an elastomer with a steel wire reinforcement'26 at the core thereof. This material is substantially non-extensible and has good frictional engagement characteristics and good abrasion resistance.

Figures 9-11 show two further shaped members 27 and 27^ which can be formed from steel which, like clips 22, have cavities 28 for receiving material 7. In the case of member 27 (Figure 9), two adjacent strands of rope- or wire-like material 7 are immediately juxtaposed,, whereas in the case of member 27^ (Figure 10) the strands are maintained in spaced-apart relationship by intervening portion 29. In order to improve the gripping characteristics of the shaped members 27 and 27^ with the rope- or wire-like material 7, the cross-section of either of these members 27 and 27^ can be provided with a cavity 30 (Figure 11) at the central portion thereof, providing a firm connection between the shaped members 27^and the rope- or wire-like material 7 when the members are crimped thereon.

As also shown in Figures 7 and 8, there can be provided an - 9 opening 31 in rubber member 23 in which can be embedded a spike 32 to perform the same function as spike 17 of Figure 5, As illustrated in Figure 6, the rope- or wire-like material 7 can be a single helical winding extending from one end ring to the other. Thus, the entire belt between the end rings, other than the connection elements,can be formed from a single piece. The number of turns can be selected in accordance with the tyre size. If the number of turns is selected to be uneven, such as the seven turns shown in Figure 6, the number of connection elements in each row considered in direction 3 is the same. When there is an even number of turns, the number of shaped members per row alternates by one each row.

In Figures 12 and 13 there are shown in sections, two embodiments of connection elements formed from an elastomer. In Figure 12, it will be seen that the sections of rope- or wire-like material 7 are maintained in spaced-apart relationship in grooves formed in body 33,while in Figure 13 the sections are adjacent each other. The material 7 can be fixed in the grooves by an adhesive or by a vulcanisation or other suitable thermal process, depending upon the materials used. Adhesive or vulcanisation is also possible for adhering the sections of strand material to each other as well as to body 33, Referring now to Figure 14, this shows an end ring 5, which is to be located on the inside i.e. vehicle side of the tyre, and which is expandable for mounting the device in order to secure the device to the tyre in an immovable manner at high travelling speeds, the other end ring 5 being relatively inextensible. However, the end ring 5 shown in Figure 14 is extensible so that it can be peripherally secured after fitting to the tyre. The end ring 5 comprises a highly elastic - 10 23123 portion such as a helical spring 34. A steel strip 35 extends within spring 34, the strip being overlapping at its ends and, preferably, overlapping sufficiently so that it extends one and one-half turns around the tyre, i.e. approximately 540°. One end of the steel strip is fixed to a bolt 36 of a clamping lock 37, while the other end is freely movable within spiral spring 34 when the clamping lock is in an unclamped or unlocked condition. After fitting the device over the tyre, a shackle 38 forming part of the clamping lock is moved to the position shown in Figure 14 in which the portions of the steel strip are clamped between the serrated portions of the clamping lock 37 firmly locking the overlapping portions of the steel strip to each other.

Thus, the length of the inner strip portion or ring 5 is fixed at the desired length. The distal end of strip 35 can be provided with a rounded end portion 39 which constitutes a guide element to assure free motion within spiral spring 34 i.e. to prevent snagging of the strip end on the spring.

Claims (18)

1. CLAIMS:1. An antiskid device, for use on a vehicle tyre, which comprises an endless belt formed of a mesh or network adapted when placed on the tyre to cover the tread and at least part of each of the sidewalls of the tyre, which belt is bounded on each side by an end ring, wherein (a) the meshes of the mesh or network are made of flexible substantially nonextensible rope- or wire-like material and each mesh adjacent the tyre tread, when the device is fitted on a vehicle tyre, is of greater dimension in a direction parallel to the direction of movement of the tyre than in a direction transverse thereto; (b) at least one of the end rings is capable of being extended to enable the device to be mounted on the tyre, and (c) all meshes adjacent the end rings are connected to the respective end rings.

2. A device according to claim 1 wherein the openings of the mesh or network, when the device is mounted on the tyre, are rhombic, with the larger diagonal running in a direction parallel to the Circumference of the tyre at least adjacent to the tread.

3. A device according to claim 1 wherein the connection points between the rope- or wire-like material and the end ring are evenly spaced around the end ring.

4. A device according to claim 1 wherein the meshes are formed by an assembly of continuous rope- or wire-like material and connection elements each of which holds fixedly together two adjacent portions of the rope- or wire-like material to form the mesh or network. 5. Windings of the helical spring whereby the circumference of the end ring can be adjustably fixed by clamping the clamp to hold the overlapping parts of the cord together.

5. A device according to claim 4 wherein the connection elements carry additional antiskid elements such as spikes.

6. A device according to claim 1 wherein the mesh or network is made up of a plurality of individual endless flexible rings of continuous rope- or wire-like material which in order to form the meshes are connected alternately with one of the neighbouring rings at positions which, when the device is mounted on the tyre, are spaced in the direction of the circumference of the tyre.

7. A device according to any of claims 1 to 6 wherein the material of the mesh or network comprises metal or textile fibres or cords.

8. A device according to claim 4 wherein the connection elements are clamps each of which comprises a distance piece between depressions for the receipt of the continuous rope- or wire-like material.

9. A device according to claim 4 wherein a rubber layer is vulcanised on to the running side of each connection element.

10. A device according to claim 9 wherein the rubber layer on each connection element has an opening to receive an antiskid spike.

11. A device according to claim 4 wherein the mesh or network is made from connection elements and a single piece of rope- or wire-like material wound helically between the end rings.

12. A device according to claim 4 wherein the connection elements have recessed portions engaging the continuous rope- or wire-like material. - 12 43122 13. - 13 ¢33122

13. A device according to claim 4 wherein the connection element is formed from an elastomeric material and is provided with a depression for receiving two adjacent portions of rope- or wire-like material or with separate depressions each for receiving a portion of rope- or wire-like material.

14. A device according to claim 4 or 10 wherein the material of the mesh or network is a rubber strip with a steel wire reinforcement.

15. A device according to claim 4 wherein one end ring is flexible but substantially inextensible.

16. A device according to claim 4 wherein one end ring comprises a helical spring, and a clamp and an overlapping cord are provided in the

17. A device according to claim 16 wherein one of the overlapping cords bears a guide element.

18. ) 18. An antiskid device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.