WO1985005597A1

WO1985005597A1 - An auxiliary device for freeing a vehicle which has been stuck

Info

Publication number: WO1985005597A1
Application number: PCT/FI1985/000047
Authority: WO
Inventors: Reijo KIVELÄ; Jorma KIVELÄ
Original assignee: Joreco Oy
Priority date: 1984-06-05
Filing date: 1985-05-29
Publication date: 1985-12-19
Also published as: FI842248A; NO860403L; FI842248A0

Abstract

Said device comprises a resilient material strip (1) to be inserted under a drive wheel of the vehicle, the forward part of said strip being provided with a sliding portion (2) and the backward part with a gripping portion (3) as an uninterrupted extension of said sliding portion. The top surface of the sliding portion (2) and the top and bottom surfaces of the gripping portion (3) are provided with roughening means (4, 5). The bottom surface of the sliding portion (2) is essentially even. In order to provide a simple auxiliary device operative on a soft ground, too, the gripping portion (3) increases in width from the forward edge thereof longitudinally with respect to the material strip (1) in a direction towards the backward edge thereof. The essentially upright side edges of the gripping portion (3) are provided with gripping means (6). In addition, the sliding portion (2) is prestressed into an upwardly arched from to essentially correspond to the shape of the vehicle wheel.

Description

An auxiliary device for freeing a vehicle which has been stuck

The invention relates to an-auxiliary device for freeing a vehicle which has been stuck, which device comprises a continuous resilient material strip to be inserted under a drive wheel of the vehicle, the forward part of said strip being provided with a sliding portion and the backward part with a gripping portion as an uninterrupted extension of said sliding portion, whereby the top surface of the sliding portion and the top and bottom surfaces of the gripping portion are provided with roughening means, the bottom surface of the sliding portion being essentially even.

In other words, the invention is concerned with a device, which, when positioned in front of a skidding wheel of a vehicle which has been stuck in snow, for instance, is automatically inserted under said wheel so as to grip snow, thus enabling the vehicle to be freed. Besides snow, said auxiliary device can also be used on other soft or slippery surfaces.

On areas with plenty of snow in the wintertime, motorists often get into a situation in which the vehicle is stuck in snow and one or both of the drive wheels begin to skid. This usually takes place on locations with little traffic, e.g. on country side roads, yards, parking places, etc., where snow is not regularly cleared away. Due to the scarse traffic, no outside help is usually available for towing or pushing the vehicle to free it.

Besides pushing and towing, a stuck vehicle can be practically freed by means of two further methods. First, the vehicle can be put in motion by shovelling enough snow away from the vicinity of the wheels. Often this method is wearisαne and time-consuming and, besides, a shovel must be at hand. Second, friction between the drive wheels and the underlying surface can be increased. This can be effected, for instance, by means of sand or gravel which is spread around the drive wheels. In general, the use of said materials is not very efficient, for a rotating wheel throws aside the sand or the like, and, on the other hand, the particles easily sink in a soft surface. In addition, the sand must be transported with the vehicle. Different kinds of available objects, such as pieces of board, etc., are sometimes inserted under a skidding wheel. This method preferably requires another person to help and does not always lead to a desired result. Further, said method is dangerous, because the objects may be thrown away under a rotating wheel.

Auxiliary devices for freeing a stuck vehicle by increasing the friction between the tire and the underlying surface have already previously been disclosed and patented. Besides metal chains, there are e.g. different kinds of friction mats. As far as is known, these have not aroused any commercial interest; obviously on account of that it is questionable whether they are of any real use in freeing a vehicle which has been stuck in snow and the drive wheels of which are deep in a hole. In most cases, a skidding wheel is not on an even surface but in a rotation hole formed thereby. Square friction mats disclosed in patents, which are roughened over the whole surface thereof, do not, consequently, operate in the best possible way. In order to provide a better grip between the tire and the friction mat, various structures to be fastened on the mat have been suggested, which are usually rather inoperative as regards the usability and the technical realization of the device. Several realizations comprise rigid metal structures, which causes a risk of the vehicle, for instance, being damaged during the transportation and usage thereof.

An example of known solutions would be the device disclosed in German Offenlegungsschrift 2,847,475 A disadvantage of said known device is its complicated, expensive construction and, besides, the poor operativeness thereof in such a situation in which the wheel is in a .hole in place of an even surface.

The object of the invention is to provide an auxiliary device, which avoids the disadvantages of the previously known solutions. This is achieved by means of the invention, which is characterized in that the sliding portion and the gripping portion are essentially equal in length, said gripping portion increasing in width from the forward edge thereof longitudinally with respect to the material strip in a direction towards the backward edge thereof, that the essentially upright side edges of the gripping portion are provided with gripping means, and that the sliding portion is prestressed into an upwardly arched form to essentially correspond to the shape of the vehicle wheel.

By means of the auxiliary device according to the invention, it is possible for a driver to free a vehicle stuck in snow or the like in most cases completely without any outside help. By using the auxiliary device according to the invention in connection with one or both of the drive wheels, the vehicle can be put in motion and displaced to such an extent that it is able to move unaidedly further. As compared with previously disclosed auxiliary devices, the solution according to the invention operates decidedly better when a wheel of the stuck vehicle is digged into snow. The auxiliary device according to the invention is technically simple to be effected and by virtue of the soft structure thereof, it does not cause any risk of damage during storing or usage.

In the following, the invention will be described more closely with reference to the attached drawing, whereby Figure 1 is a side view of an auxiliary device according to the invention,

Figure 2 is a top view of the auxiliary device of Figure 1

Figures 3-5 illustrate the essentials of the operation of the auxiliary device according to the invention, being side views at different stages of the operation,

Figure 6 illustrates the principal features of an advantageous detail of the invention in a side view.

The invention is formed by a resilient, ductile material strip 1, a gripping mat of rubber or plastic, for instance, the side and top views thereof being shown in Figures 1 and 2 respectively. As to the operation, said gripping mat can be divided into a sliding portion 2 positioned in the forward part of the material strip 1 and a gripping portion 3 forming an uninterrupted extension of said sliding portion. The whole top surface of said gripping mat is provided with roughening means 4, e.g. teeth or the like, in such a manner that the friction thereof against a vehicle tire is high. The sliding portion 2 is resilient, being even on the bottom surface thereof, or, alternatively, grooved in the longitudinal direction, whereby the friction thereof against the underlying surface is low. The width of the sliding portion 2 is advantageously smaller than that of an average tire tread. The bottom surface of the gripping portion 3 is provided with roughening means 5, e.g. teeth, in such a manner that the friction thereof against snow or the like is high. According to the invention, the gripping portion 3 sidewardly increases in width in a direction away from the sliding portion 2, whereby also the essentially upright side edges thereof are provided with gripping means 6, which can be teeth, for instance.

The sliding portion 2 is, according to the invention, prestressed into an arched form, as clearly appears from Figure 1 in particular, whereby the forward edge thereof is tightly pressed against the vehicle wheel when it slides under said wheel. Thereby the possible penetration of the forward edge of the material strip 1 downwardly into the snow is avoided. When the gripping mat according to the invention is used for freeing a stuck vehicle, it is positioned in front of the skidding wheel in the desired starting direction according to Figure 3. The Figure shows a vehicle tire 7, which is digged into a hole 8 formed in snow, and the gripping mat when positioned in place, said mat being formed by a resilient material strip 1. The desired starting direction of the vehicle and the direction of rotation of the wheel are indicated by the arrows L and P. When rotating, the tire 7 first draws the sliding portion 2 in the forward part of the material strip 1 under it in a direction indicated by the arrow N, because the friction between the tire 7 and the top surface of the material strip exceeds the friction between the sliding portion 2 and the underlying surface. In Figure 4, the sliding portion 2 is already positioned under the tire 7. Thereafter the friction between the underlying surface and the material strip increases, because the roughening means Ξ of the bottom surface of the gripping portion 3 start to bite into the surface beneath. At the same time, the backwardly enlarging shape of the gripping portion 3 and the gripping means 6 of the side edges cause the material strip 1 to be supported also on the sides of the rotation hole formed by the tire 7. In Figure 5. the above steps have already taken place and the vehicle can be displaced by driving on the material strip 1 thus stuck on the underlying surface.

When necessary, the roughening means 5 of the gripping portion 3 can be provided with prongs or the like, which are made of metal, for instance, and which protrude from the surface, being intended for increasing friction between the gripping portion 3 and the surface beneath in case the device according to the invention is used on a hard slippery surface (e.g. on ice) .

Besides, the sliding portion 2 can be advantageously vertically thickening in a direction backwards from the forward edge, whereby it slightly lifts up the vehicle when inserted under the vehicle tire 7, which is of advantage if a snow drift supports the vehicle from the chassis.

By forming the sliding portion 2 so that the roughening means 5 of the gripping portion 3 are, in the rest position, out of contact with the surface beneath (cf. Figure 1), the insertion of the material strip 1 under the tire 7 is made easier. This is further facilitated by providing the backward edge of the gripping portion 3 with an even surface area 9 of low friction. Moreover, the forward edge of the sliding portion 2 can be advantageously provided with one or more projecting elements 10, e.g. hook-like claws or simila, structures of metal or the like, which are intended for ensuring that the sliding portion 2 at the initial stage sufficiently firmly grips the tire 7 so that the sliding portion 2 starts to moveunder the tire 7. Figure 6 shows an example of one preferred embodiment of said projecting elements 10. The metal projecting element 10 on the forward edge of the sliding portion 2 grips the configuration of the tire 7 and the tire, under the rotation thereof, further draws said sliding portion 2 under it.

If the tires of the vehicle are provided with splash guards, it may be advisable to bend them up during the freeing of the stuck vehicle. Any suitable holders can be used for this purpose, said holder being positioned so as to strain a bent resilient splash guard. The holder is maintained in place, for. instance, by means of the tension force caused by said splash guard.

The embodiment examples described above are, of course, not intended to somehow restrict the invention, but the invention can be modified within the scope of the attached claims in various ways. So it is self-evident that the roughening means 4, 5. for instance, do not need to be exactly similar to those shown in the Figures, but roughening means such as toothing, different kinds of patterns and anything of the kind can be used. The same applies to the gripping means of the side edges of the gripping portion. The projecting elements 10 provided on the forward part of the sliding portion can also be effected in various ways, etc.

Claims

Claims:

1. Auxiliary device for freeing a vehicle which has been stuck, which device comprises a continuous resilient material strip (1) to be inserted under a drive wheel (7) of the vehicle, the forward part of said strip being provided with a sliding portion (2) and the backward part with a gripping portion (3) as an uninterrupted extension of said sliding portion, whereby the top surface of the sliding portion (2) and the top and bottom surfaces of the gripping portion (3) are provided with roughening means (4, 5) , the bottom surface of the sliding portion (2) being essentially even, c h a r a c t e r i z e d in that the sliding portion (2) and the gripping portion (3) are essentially equal in length, said gripping portion (3) increasing in width from the forward edge thereof longitudinally with respect to the material strip (1) in a direction towards the backward edge thereof, that the essentially upright side edges of the gripping portion (3) are provided with gripping means (6) , and that the sliding portion (2) is prestressed into an upwardly arched form to essentially correspond to the shape of the vehicle wheel (7) .

2. Auxiliary device according to claim 1, c h a r a c t e r i z e d in that the forward edge of the sliding portion (2) is provided with at least one projecting element (10) for gripping the tire (7).

3. Auxiliary device according to claim 1 or 2, c h a r a c t e r i z e d in that the sliding portion

(2) is thickening in a direction backwards from the forward edge of said portion (2) .

4. Auxiliary device according to claim 1 , c h a r a c t e r i z e d in that the sliding portion (2) is provided with such an arching that, in the rest position, the roughening means (5) of the gripping portion (3) are out of contact with the underlying surface, and that an essentially even area (9) is formed on the bottom surface of the backward edge of the gripping portion (3) so as to facilitate insertion of the material strip (1) under the wheel (7) .