EP0139737A1

EP0139737A1 - Anti-skid device for vehicles

Info

Publication number: EP0139737A1
Application number: EP19840901830
Authority: EP
Inventors: Ingvar Westerberg
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-04-18
Filing date: 1984-04-18
Publication date: 1985-05-08
Also published as: SE8302155D0; WO1984004071A1; SE436720B; SE8302155L

Abstract

Dispositif anti-dérapage constitué par une courroie (1) s'étendant autour de la circonférence de la roue, laissant un jeu (16) entre la courroie et la roue. La courroie est reliée à l'aide de rayons (5,14) à un tourillonage central (9, 10, 11) de manière à pouvoir tourner par rapport à la roue. Le tourillonage (9, 10, 11) est fixé à la roue à l'aide de boulons (8) se vissant dans les écrous (7) de jante de la roue.Anti-skid device constituted by a belt (1) extending around the circumference of the wheel, leaving a clearance (16) between the belt and the wheel. The belt is connected using spokes (5,14) to a central journal (9, 10, 11) so that it can rotate relative to the wheel. The journal (9, 10, 11) is fixed to the wheel by means of bolts (8) which are screwed into the wheel rim nuts (7).

Description

Anti-skid device for vehicles

This invention relates to an anti-skid device for vehicles and in particular one suited for car^'s. As anti-skid devices for cars it has long been known to use snow-chains. The chains " increase the grip considerably, but their mounting is time-consuming" and demands in general a certain practice, even if attempts have been made with quick-m^'ountable snow- chains, as well as simpler swift mounted links. Snow-chains furthermore have the draw-back that they do not permit any higher speed, which with a great probability result in that most car-drivers or owners are uninterested in snow-chains but for rather extreme cases. Furthermore there exist anti¬ skid devices constituted by a number of U-shaped members gripping over the tyre and held in place by a tensioning device. These devices are however also subjected to the draw- back that they do not allow driving with any greater speed and they should rather be considered as aids to get a car moving:, in deep snow. Since the U-shaped means are few and thick a very uncomfortable driving is the result if one tries to drive any longer stretches with them. Another solution is to change to special winter tyres provided with metal studs. Apparently this is relatively costly, in particular as the tyres intended for use on ice and snow mostly are used on bare ground, which in turn means that studs and tyres are worn out prematurely and when one day the extra road grip is needed it might have been so far reduced that the gain by useing special winter tyres is insignificant and in the mean¬ time the tyre cost have been increased. On some surfaces the stud provided winter tyres can result in less grip than tyres without studs and furthermore metal stud provided tyres are not permitted in all countries.

In this context a solution used for greater vehicles should also be mentioned, namely that with special devices when needed, pieces of chains mounted on a small wheel are brought under the vehicle wheel by forceing the chain provided wheel in contact with the side of the vehicle wheel, rotating the chain provided wheel or pully. This is however a solution that OMPI is very difficult to use for cars, not only due to the consi¬ derable costs but also in view of the very small available space.

5 In view of the above problems the object of the invention is to provide an anti-skid device for motor vehicles and in par¬ ticular cars, that is simple to use, that requires a minimum of installation measures, that are cheap to manufacture, that can be used instead of studded winter wheels, i.e. that can

1_Q be used not only for shorter stretches under extreme diffi¬ culties, but also for the driving of longer stretches with high speed without loss of travelling comfort. This object is achieved in accordance with the invention with an anti¬ skid device, including a friction increasing belt that in

-J5 use is placed around the wheeel and furthermore means to fasten and hold this belt rotatebly at the outer side of the wheel and holding the belt in the correct lateral position s^'o that the friction increasing belt can be in contact with the ground under the wheel.

20

The reason for the anti-skid device to be applied rotatebly at the wheel is perhaps not entirely obvious, 'but if this is not the case the anti-skid device must be fastened relative the wheel so powerful that the fastening can take a very great

25 part of the driving forces since interrelated slip between wheel and anti-skid devices not can be excluded. This is one of the reason why so many of the above mentioned known devices are so clumsy and difficult to apply. The anti-skid device according to the invention need only to be kept in place

30 between wheel and ground and since the driving forces are circumferentially directed the means holding the anti-skid device laterally on it place only need to cope with moderate forces. With the means defining the lateral position in the shape of more or less recilient spokes or alike a simple

35 mounting of the anti-skid device is possible since no wheel has to be lifted up from the ground, but the anti-skid device is quite simply locked, for instance in a central bearing or journal to the wheel and the anti-skid device will res i- liently be pushed over the wheel but for the section where this rests on the ground. As soon as the wheel starts to roll even this part of the anti-skid device will move in over the traction of the wheel.

Since the friction increasing part of the anti-skid device is in the shape of a belt it can resist the centrifugal forces even at high speed.

In view of the fact that the car tyres of today are compara¬ tively broad (which gives an increased grip in good weather) with accompaning tendency for water planing in snow and water mixtures.thereof it can be beneficial if the friction in- creasing belt does not extend over the entire traction of the wheel, but instead only extend over half or a part of the traction of the tyre. In this way the risk of water planing is diminished and the contact pressure against ice and snow is increased. The belt can be of rubber o plastic and provi- ded with metal studs or other gripping means. By a suitable construction of the rotabel journaling and a snap device co¬ operating therewith the mounting of the device on each wheel of the car can take place so quickly that no one should be reluctant to mount the anti-skid device when the need for it is felt.

The rotatable journaling and mounting of the device can either take place at the. centre of the wheel by means of special devices mounted together with the wheel, but it is of course also possible to mount these devices on the axial shaft or that the hub cap is provided with means capable of cooperating with the anti-skid device.

Further advantages and features of the invention will be apparent from the following description of two embodiments of the invention referring to the drawings. Fig 1 shows an anti-skid device in accordance with the invention in a radial section and fig 2 an alternative central journaling of the anti-skid device.

At the bottom of fig 1 the belt 1 is shown in a section and includes two cord layers 3, 4. The inner 3 of these extend laterally out into spoke-like elongations of the belt 1. These spoke-like elongations 5 extend round the shoulder of a tyre 2 in towards the centre of the wheel.

The wheeldisk is mounted by means of wheel nuts 7, these are somewhat longer than ordinary type and in their outer ends bolts 8 are used to mount a disk 9,provided with axle shaft 10.On this shaft a bearing 11 is held by a nut 12. The bearing, that with its inner race is fixed on the shaft has its outer race fixed in a hub disk 13 provided with spoke-like elonga¬ tions 14 jointed to the elongations 5 of the belt 1 by bolt and nut means 15.

As can be seen a small play 16 exists between the belt and . the tyre^" enabling the belt without "chest-drawer effects" to slip on place over the wheel even when the device is moun¬ ted with the wheels standing on the ground, so that when mounted the belt is forced to the side at the ground. This is possible due to the recilience or elasticity in the spoke- like elongations 5 on the belt. The spokes are all together six to their number. The play furthermore res lts in a slight¬ ly excentric rotation for the belt relative the wheel, which excentricity is possible and taken up by the re-silience of the spokes.^'

In fig 2 an alternative embodiment of the central journaling of the anti-skid device is shown. In this embodiment the hub disk 17. ith a radial play is journaled between two disks 18 and 18' arranged on a common casing that when the anti-skid device is mounted is pushed over the extra shaft 19 mounted on the wheel disk. Thereafter the common casing is locked on the shaft 19 by aid of a snap-lock or the like. With this i journaling the anti-skid device can rotate excentrically relative the wheel without spring action from the spokes.

Since the entire anti-skid device is rotatable relative the wheel the driving forces will only be transferred from ground to anti-skid device and further on to the wheel in the actual contact surface of the wheel. Consequently the power transfer will take the shortest possible way even if a certain slip exists between wheel and anti-skid device. This slip can neve be entirely eliminated and if the anti-skid device should be stiffly mounted at the centre of the wheel this would imme¬ diately result in that the forces on the spokes would become so great that these would break, alternatively it would be necessary to fabricate those much stronger than what is neede in accordance with the invention.

Since the amount of play between wheel and anti-skid device is not overly critical as long as the anti-skid device can slip on place it is possible to mount the anti-skid device on slightly different diametered tyres or worn tyres with retained function. As a result the anti-skid device can be fabricated in a number of dimensions that is less than the number of different tyre dimensions, as long as the excentri- city between wheel and anti-skid device can be taken care of by bearing, spokes or the like. Of course excentrical rotation permitting means might be included in the joints or in the spokes in some other not described way, without departure from the scope of the invention.

T e belt shape, of the anti-skid device means that it well re¬ sists centrifugal forces without powerful and heavy mounting means. Due to the rotatability the anti-skid device can be made lighter than what is the case with the known devices, this since no driving forces need to be transferred by the positioning means. .

OMPI

Claims

1. Anti-skid device for motor vehicles , in particular cars, c h a r a c t e r i z e d i n that it includes friction increasing means in the shape of a belt that when used extend around the circumference of the tyre, and means laterally positioning the belt in this position rotatable relative the wheel, when mounted on this.

2. Anti-skid device according to claim 1 , c h a r a c t e¬ r i z e d i n that the means for lateral positioning of the belt in the correct working position are elastic and that the inner diameter of the belt is somewhat greater than the outer diameter of the wheel, so that the anti-skid device can be mounted centrally on the wheel without lifting the wheel from the ground, when mounted in this fashion the belt will at the ground initially be at the side of the wheel, then to spring in over the wheel when this starts to rotate.

3. Anti-skid device according to claim 1 , c h a r a c t e¬ r i z e d i n that the journaling and fastening of the anti¬ skid device takes place at the centre of the wheel.

4. Anti-skid device according to any of the claims 1 or 2; c h a r a c t e r i z e d i n that the anti-skid device is fastened in a hub cap or the like means fastened to the wheel.

5. Anti-skid device according to any of the preceding claims c h a r a c t e r i z e d i n that the belt is connected with a fastening and bearing means by spokes.

6. Anti-skid device according to any o^"f the preceding claims c h a r a c t e r i z e d i n that the spokes partly are integral with the belt itself.

7. Anti-skid device according to any of the claims 1-5, c h a r a c t e r i z e d i n that the outward surface of the belt is profiled or provided with spikes studs or the like in order to increase the friction and the grip on the ground.

8. Anti-skid device according to any of the preceding claims c h a r.a c t e r i z e d i n that the anti-skid device laterally only extend over a part of thread of the wheel.

9. Antirskid device according to any of the preceding claims, c h a r a c t e r i z e d i n that the fastening of the device to the wheel is by means of a snap-lock.

OMPI

10. Anti-skid device according to any of the preceding claims c h a r a c t e r i z e d i n that the journaling of the anti-skid device relative the wheel is capable of handling the excentricity between belt and wheel.

11. Anti-skid device according to any of the preceding claims 2-10, c h a r a c t e r i z e d i n that the laterally posi¬ tioning means, for Instance spokes is capable of handling the excentricity between wheel and belt rotation.

OMPI