Patent Application
20080230165
The aim of the present invention is an antiskid device for vehicles and, in particular, an antiskid device based on the coating of the tire tread with a textile element.
The antiskid devices for vehicles are normally used for increasing the friction between the wheels of a vehicle and the surface on which they roll whenever the adhesion is reduced and namely, for example, in winter conditions due to snow or ice, on particularly muddy grounds, on gravel or sand.
The tire antiskid devices based on the coating of the tread with a textile element have been known since long.
More particularly, such devices are equipped with a belt, suitable for surrounding the tire tread, which presents expansions which can be carried out both with its own material and with a different one, associated with a resilient or metal element for its fixing to the wheel.
It is well known that for the belt fabrics with a flat construction are used, possibly coated with a spreading or with abrasive material for increasing the effectiveness and the service life.
The known devices present however some drawbacks. First of all, the antiskid action is exclusively assigned to the adhesion, or to the greatest friction coefficient of the fabric with respect to the one of the tire compound. In this way, in the most difficult situations, the effectiveness of the device action can be limited and, therefore, not to lead to the desired results.
Furthermore, the structure of the fabrics currently used makes the devices very stable from the dimension point of view, that it snot resilient. In this way, during the adjustment to the different dimensions of the tires, wrinkles and crimps on the rolling surface are formed, which, besides decreasing the internal adhesion between tire and device, form concentration points of the stresses and therefore of a higher wear, which limit the service life thereof. In fact, also following to a reduced use, such devices tend, for example, to fray themselves.
In this situation, the technical task placed at the base of the present invention is to obviate to the drawbacks above mentioned.
Therefore, an aim of the present invention is to suggest an antiskid device for vehicles which offers a good alternative, both in terms of effectiveness and safety, to the conventional snow chains, considering that in many countries, in order to avoid damages to the feather edge, they are forbidden, for that they can not be mounted on some vehicles, such as sports-cars or those with rims of a very high diameter.
Still an aim of the invention is to present an antiskid device for vehicles capable of carrying out an adequate antiskid action so as to be able to represent, for the vehicle's driver, a safety instrument to be housed in the vehicle itself.
It is also an aim of the present invention to show an antiskid device for vehicles which has a remarkably long service life.
Finally, a further aim of the invention is an antiskid device for vehicles which ensures an adequate comfort in the driving and which is manageable, easy to use and transport, simple to carry out and with a limited cost.
These and other objects, which will better result during the following description, are attained, according to the present invention, by an antiskid device for vehicles according to the appended claims.
It is now reported, by way of indicative and not limiting example, the description of a preferred but not exclusive embodiment of the invention. Moreover, the invention is more particularly described with the help of the following drawings:
With reference to the mentioned drawings, an antiskid device for vehicles according to the invention is integrally shown by numeral 1. Such device 1 includes a band 2, carried out with fabric 7, suitable for surrounding at least the tread 13 of a vehicle tire and mounting means 10 associated with the band 2 in order to maintain it in position around the tread 13 and for tightening the device 1 itself on the wheel 14 of the vehicle on which it is mounted, so as to prevent unintentional disengaments. The device 1 is characterized in that the band 2 presents engagement means 8 in correspondence with at least a portion of an outer surface 4 thereof for increasing the friction between the tire and the road. In particular, such engagement means 8 are carried out through the same fabric 7 of the band 2. In fact, the engagement means 8 include relief ribbings 9, diagrammatically shown in
In this way, the antiskid action is exerted not only by adhesion, as in the traditional applications with flat fabrics, but also because of the positive force derived from the penetration of the ribbings 9 in the road-bed consisting of, for example, snow, ice, mud or sand. For the purpose of ensuring an adequate action effectiveness, the yarn used for the fabric 7 of the band 2 must have a remarkable friction and wear resistance, resist to low temperatures without getting brittle, it must not absorb water nor modify its features or damage itself with the humidity. For this reason, the synthetic fibers are more suitable, as the natural fibers, for examples can rot following to a prolonged contact with the water.
Preferably, therefore, the fabric 7 is obtained with a continuous multifilament polypropylene yarn with a fineness of 800-1200 dTex, which joins the advantages of the lightness and the ecological compatibility in all the steps of the life cycle of the product (production, processing, disposal).
Furthermore, in order to increase the resistance of the manufactured article, yarns made of high resistance materials, such as aramide resins (kevlar) or textile steel, can be introduced in the zones with a higher stress, such as the ribbings 9.
Advantageously, the fabric 7 suitable for forming the band 2 of the device 1 can be obtained with a rectilinear needle loom, with a “raschel”-type linear textile machine or with a circular textile machine. A preferred embodiment of the device 1 foresees a fabric 7 carried out through a “raschel”-type linear textile machine with a non-run “tricot” interlacement with a throwing on multiple needles, on a loom with 2 or more bars of 6 needles/1″, using a multifilament continuous polypropylene yarn with a fineness 1111 dTex. In this case, the obtained fabric 7 has a weight of 500 g/m2 with 7 small chains/1″ and 6 lacings/cm and, as above described, a thickness of about 0.4 in the “valleys” and about 1.5 mm on the “crests” consisting of the ribbings 9.
Advantageously, the fabric 7 can also be opportunely thermally stabilized (for example through a passage in a tenter frame) in order to make easier the following cutting and sewing operations required for carrying out the band 2.
Furthermore, the band 2 of the device 1 can include grasp means (not shown) in correspondence with at least a portion of an internal surface 3 thereof (namely directly contacting the tread 13 of the tire) for increasing the friction between the device 1 and the tire.
In particular, such grasp means can include relief elements directly carried out on the fabric 7.
In the various embodiments of the inventive concept described, the band 2 can show both a cylindrical and a conical sections. By carrying out a band 2 with a slightly conical instead of a cylindrical section, the device 1 becomes suitable for a wider range of tires so as to reduce the number of sizes required for satisfying the market.
Moreover, if the band 2 of the tread 13 is cylindrical, the device 1 can advantageously be carried out by means of a circular textile machine in a single piece without seams.
Both in case of a cylindrical and a conical sections, the portion of band 2 placed in correspondence with the outer side surface 15 of the wheel 14 (or the one opposite to the connections with the other vehicle elements) can be closed, so as to cover such surface 15.
Always according to the invention, the mounting means 10 include a mounting element 11, generally a resilient element, associated with at least one of the two side portions 5a, 5b of the band 2 so as to maintain the device 1 in position on the tread 13. Alternatively, such mounting element 11 can include a semirigid cable, which can be closed, made of a metal, plastic material or with the fabric 7.
In a first embodiment, therefore, the device 1 consists of a single band 2, obtained with a fabric 7 having the features above described, which can be removably housed and fixed around the tread 13 of the tire by means of the mentioned mounting element 11 which can be associated both with the inner side portion 5a and with the outer one 5b of the band 2 or only with the inner portion 5a if the outer one 5b is closed for covering the outer side surface 15 of the wheel 14 itself.
In a second embodiment of the device 1, preferred to the first one and shown in the figures, the mounting means 11 can include, moreover, at least a flexible side belt 12a, 12b interposed between the side portion 5a, 5b of the band 2, to which it is preferably sewn and the mounting element 11. In this case, the device 1 can show, in a first embodiment, two flexible side belts 12a, 12b, one associated with the inner side portion 5a and the other one to the outer one 5b of the band 2, which end with the mounting means 10. Alternatively, in a second embodiment, the outer side belt 12b can be closed so as to cover the outer side surface 15 of the wheel 14 and the mounting element 11 is only associated with the inner side belt 12a (
In its preferred embodiment, the device 1 can advantageously include one or more bands 6 arranged in correspondence with two points substantially placed at 180° of at least one of the side portions 5a, 5b of the band 2 for facilitating the self-centering of the device 1 itself and its removal from the wheel 14. In particular, the preferred embodiment of the device 1 includes two bands 6 sewn at the outer side portion 5b of the band 2, which diametrally cross the outer side surface 15 of the wheel 14, substantially orthogonal therebetween (
According to the invention, the band 2 can be closed, being carried out in a single circular piece or being sewn, or open. If the band 2 is open, the device 1 includes means for closing the band 2 during the mounting step around the tread 13 (variation not shown). Such means can include, for example, a velcro application.
The device 1 of the invention is structured for being easily bent for facilitating the transport and for reducing the encumbrance, considering the restricted spaces within the vehicles.
For the mounting of the preferred embodiment of the device 1 on the wheel 14 of a vehicle, it is necessary to adhere the band 2 to a portion, as wide as possible, of the tread 13 and place the inner side belt 12a and the resilient element in correspondence with a portion of the inner side surface 16 of the wheel 14. Subsequently, it is necessary to remove the vehicle such that the wheel 14 substantially performs half turn, for being able to house the remaining part of the band 2 and the inner side belt 12a on the portion of the tread 13 which, in the previous step, was contacting the road-bed.
In practice, the used materials, as well as the dimensions, could be any one, depending on the requirements.
Furthermore, all the details can be replaced with other technically equivalent elements.
The invention attains important advantages.
First of all, the action of the device of increasing the adhesion with the ground results very effective, even without the help of coatings of the band with other materials, moreover very expensive, as in the traditional applications. In fact, the antiskid action is exerted not only for the higher adhesion of the band fabric relative to the tread compound, as in the known devices carried out with flat fabrics, but also for the positive thrust derived from the penetration of the ribbings in the road-bed. Furthermore, the particular structure of the band fabric, above all when the ribbings are slanted with respect to the direction perpendicular to the rolling direction of the wheel, imparts to the vehicle a greater side stability to the side skipping, a high driving comfort and a lower noisiness due to the progressive contact of the ribbings with the ground.
A further advantage is that the device shows a remarkable wear resistance and, accordingly, a remarkable service life. This is due to the natural elasticity of the knitted fabric used, which further involves a best adaptation of the device to the tire shape, reducing the formation of wrinkles and crimps on the rolling surface during the running of the vehicle.
Another advantage is the easiness of bending the device on its own, which facilitates the transport and the placing in the vehicle, and the simplicity of use.
This latter feature is very important above all in winter conditions with severe temperatures. The advantages above described point out how a device according to the invention can represent a good alternative to the traditional snow chains.
| Number | Date | Country | Kind |
|---|---|---|---|
| BS2005A000114 | Oct 2005 | IT | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IT2006/000579 | 7/26/2006 | WO | 00 | 3/20/2008 |
