WO1981000831A1

WO1981000831A1 - Traction belt for tyred vehicle

Info

Publication number: WO1981000831A1
Application number: PCT/GB1980/000143
Authority: WO
Inventors: Wellings J Horton
Original assignee: Wellings J Horton
Priority date: 1979-09-18
Filing date: 1980-09-17
Publication date: 1981-04-02
Also published as: DE3049910A1; EP0035512A1

Abstract

A device for shrouding the tread regions of a tyre so as to improve the grip of the tyre with a road surface under conditions of snow, ice mud etc, includes an endless track forming element (7) which circumscribes the tread region (3) of the tyre (1) on which it is fitted. A series of openings (9) is provided in the element the openings being spaced around the circumference of the element. In use the extra grip is afforded by the snow, ice, mud being able to enter the openings thereby to give greater adhesion. The flexure of the tyre and element (7) serving to eject the snow, ice, mud from the openings so that as the vehicle travels openings are continuously presented. Preferably the element is made from a conventional tyre by punching out holes in the tread regions thereof.

Description

TRACTION BELT FOR TYRED VEHICLE

BACKGROUND OF THE INVENTION

This invention relates to road engaging devices for the uheels of vehicles such as cars, lorries, and civil engineering vehicles.

THE PRIOR ART

It is knoun that the tyres conventionally fitted to vehicles for general use are provided uith treads intended to provide adequate road holding capability over a uide variety of possible vehicle operational conditions including amongst other things, the nature of the road or other surface over uhich the vehicle travels; the type of vehicle; the loading of the vehicle; tyre pressures; the manner in uhich it is driven; weather conditions; etc. Since each one of the above mentioned variables can vary uidely it has been found that the conventionally used tyres may not be able to provide under certain, not necessarily extreme, conditions the requisite degree of adhesion with the road or the like, uhereby the driver may not be able to control adequately the vehicle or the vehicle may not respond sufficiently to steering and drive requirements.

In particular, the presence of ice, snow or mud can give rise to adverse tyre adhesion. In an attempt to overcome this loss of adhesion in such conditions it has been proposed to provide an arrangement of chains which so fit onto vehicle wheels as to provide lengths of chain extending across the tyre at locations spaced around the periphery of the tyres. The purpose of the chains is to provide regions which will 'dig into' or otherwise cut the surface of the snow and/or ice over which the chains travel and thus provide a higher degree of adhesion as compared with that obtained in the absence of the chains.

In practice, chains rub against and thus tend to damage the tyres to which they are fitted. Such damage can also readily occur if the links of the chain entrain fragments of stones or the like.

OBJECT OF THE INVENTION

It is an object of the present invention to provide a traction tread for use with a vehicle tyre or tyre assembly.

SUMMARIES OF THE INVENTION

According to a first aspect of the invention there is provided a traction device for shrouding the tread regions of a vehicle tyre, the device including for at least one of the side walls of the tyre a ring member which is adapted partially to shroud the adjacent side wall of the tyre and which is co-operable with the wheel upon which the tyre is fitted, the device also including an endless track portion having a plurality or recesses or openings or a combination of recesses or openings defining radially extending walls, the reeesses or openings being spaced around the track portion, said track portion being adapted for attachment to the tyre in such manner that when the tyre is inflated the track portion shrouds the tread region of the tyre. A method of providing the tyre of a vehicle wheel with a traction tread, the method comprising the steps of shrouding the tread region of the tyre with a flexible cover uhich circumscribes at least the tread region and which is provided with openings or recesses in the part thereof that co-operates with the tyre tread region, and securing the flexible cover in place by securing arrangements which co-operate with both sides of the structure of the wheel. Preferably the endless track forming portion / flexible cover is formed from a conventional tyre whose tread region has been part removed to form the openings or recesses, and whose side walls are adapted for co-operation with means for retaining the track forming portion/flexible cover in its operational position. Conveniently, the wall defining openings or recesses are so located in the tyre being modified that at least a part ofsome of the openings or recesses extend to the shoulder region betueen the tyre side walls and the tread region of the tyre.

Preferably, each of said ring members has a plurality of apertures circumferentially spaced around the associated wall of the tyre from which the track farming portion/flexible cover is formed, which apertures are positioned to be engageable with location means provided on the associated ring member.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the invention and to show how to carry the same into effect reference will now be made to the accompanying drawings in which:-

Figure 1 is a side elevation of the traction device/flexible cover of the invention mounted on the tyre of a vehicle wheel; Figure 2 is a sectional view to an enlarged scale taken on the line II-II of Figure 1, the Figure illustrating two forms of a detail of the device;

Figure 3 is a perspective view of a part of the device/flexible cover of Figures 1 and 2, a part of a tyre also being shown: and

Figure 4 is a very schematic representation of an arrangement for cutting openings into a conventional tyre for the purposes of producing a device/flexible cover of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings and particularly to Figures 1,2 and 3, a vehicle wheel unit 1 has a conventional tyre 2 fitted thereto. The tyre 2 has a tread section or region 3, side walls 4, and rim beads 5 which engage with the wheel flange or rim structure 6 of the wheel ( only a part of the wheel is shown in Figure 2)

The tyre 2 is partially shrouded or enclosed by a traction device 7, the latter being capable of flexure when subjected to the movements of the vehicle so that the device can be regarded as a flexible cover. The device 7 comprises a road surface engaging portion 8 which extends across the full width of the tread region of the tyre 2 and around the complete circumference of the tyre 2. The portion 8 conforms to the general profile of the tyre tread region 3. The portion 8 is provided with a plurality of openings 9 which in the embodiment shown are arranged in two rows 10 and 11. The openings 9 in the rows 10 and 11 can be in side-byside relationship as shown or arranged in staggered relationship.

The openings 9 can have a variety of shapes. For example, they can be as shown in the drawings or they can be oval, elliptical, circular or other shape that may be found suitable. In each case it is important that the side ualls 12 of the openings 9 should be inclined outuardly so that the outer perimeter of each opening is larger than that of the inner surface of the opening.

It is also possible to provide different arrangements of the openings from that illustrated. For example, there can be more than two rous of openings of differing sizes arranged in regular or irregular arrangement. In practice, the arrangement of the openings, the number of rous etc., would be related to the dimensions of the wheel tyre and in particular the axial width of the tyres in relation to the diameter, the diameters of the tyres and the nature of the tread formation.

In addition, the device 7 has relatively narrow sidewall forming portions 13 which are each provided with lugs or flaps 14. The number of lugs or flaps can vary, the number being chosen as thought expedient. For example, four, six, eigth or ten. In the Figure the portions 13 are shown as having six lugs or flaps 14.

The flaps 14 are each apertured for engagement with a hut and bolt assembly 16 connected with an annular ring member 17 which is adapted at its inner peripheral region 18 for firm engagement with the wheel structure 6 particularly in the region of the tyre well.

In practice, the mode of engagement can take various forms and in any particular case the precise shaping of the inner region 18 will be related to the form of the wheel structure 6. To illustrate this point the left hand side αf the wheel flange rim has been shown with a hook formation 6A into which a suitably turned-in part 18A of the region 18 engages. The right hand side of the Figure shows illustrates an alternative form. It will be understood that in an actual wheel structure the two sides of the wheel structure will be of the same form.

Each ring member 17 can be formed of any convenient material metal or plastics. In the latter case a suitable plastics material can be polypropolene. In the case of a metal an alloy of steel and Zinc may be used. One such alloy is known under the Trade Name Zintex. Conveniently, the ring member can, in the case of a metal can be pressed or formed by a spinning operation.

The ring member is provided with a plurality of bores 20 one for each flap 14 into which are fitted countersunk bolts 21 the latter being held firmly in place by nuts 22. The bolts 21 and nuts 22 form the assemblies 16. The bolts project outuardly from the ring member sufficiently not only to be engageable by the flap but also to be able to receive a retaining nut 23 and a washer or plate 25. The washer assists in providing lateral support to the flap 14. The flap region in the vicinity of the ring member is effectively reinforced by reason of the thickening of the wall 13 at the regions closer to the originally provided bead, which is not shown and which is removed during formation of the flaps 14.

It will be understood that whilst a conventional hexagonal nut is shown other forms of nut can be used i.e., domed nuts or nuts requiring the use of a key or the like for the purposes of tightening The outer periphery 19 of the ring member 17 is formed with a bead 19A which reduces the possibility of an edge region of the ring member from cutting into the tyre 2.

The device according to the invention can be fitted as follous :- The wheel is removed from the vehicle ( or a spare wheel utilised) since this facilitates the fitting process. The tyre is deflated sufficiently to allow the side wall 13 and the flaps 14 on one side of the device 7 to be aligned with and slipped over the tread region of the tyre 2. The device 7 is then positionally adjusted until the tread portion 8 is correctly symmetrically positioned on the tyre 2. The tyre 2 is then initially reflated to a pressure level which is found to be sufficient to hold the device firmly in place.

The ring member 17 or members 17 are then attached to the vehicle wheel so that the assemblies 16 can engage the bores in the flaps 14, with the bolts projecting outuardly to receive the associated washers and nuts 23.

The tyre 2 is then finally reflated to its correct running pressure thereby exerting additional pressure on the securing arrangements which aids in the retention of the device in its operational position. It will be found, in practice, that when the device 7 is under tension from the securing arrangements and the effect of air pressure within the tyre 2, the device 7 tends to push the central part of the tyre tread region 3 inuardly so that a slight concavity is produced in the tyre tread region 3. This has been found to aid in maintaining the device in position.

When a vehicle fitted with devices according to the invention is used on muddy roads or roads covered snow or ice it has been found that the provision of the openings or recesses 9 improves the road holding to such an extent that the need for chains is avoided in many situations. During use any mud, snow or ice or lumpy slush which collects in the openings 9 is urged out from the openings 9 by the flexing of the device 7 during rotation of the wheel unit. Since device of the invention as so far described is essentially a modified tyre it is not likely to cause any damage to the roads over which it travels in the absense of snow or ice. Furthermore, since the device shrouds the tyre the load distribution is not localised in the same manner as that of a set of chains. Consequently, there is not the same likelihood of damage to the tyre tread region.

Because of this the device of the invention has found to provide a far greater freedom of usage in situations where chains would be likely to cause damage. For example, where stretches of road are covered with snow, slush or ice are interspersed with stretches of road relatively free of such materials. In a modified form of the device of the invention

(not shown) an additional gripping facility can be provided by provided by inserting stud attachment elements in the tread portion 8, whereby studs can be releasably attached to the device 7 to take into account more severe conditions. When such studs are not required they can be readily removed.

It will be understood that various configurations and shapes of the openings 9 can be used in conjunction with various relative spacings of the flaps. In the case of the latter, depending upon the diameter of the wheel unit 1, the number of lugs or flaps can be other than the six shown i.e., 4,5,7,8,9,10 etc. It has been found that eight lugs or flaps is a convenient number for many of the wheels commonly used on motor vehicles. Conveniently, the devices of the present invention are constructed from tyres which are part worn and are not acceptable for further normal use as an inflated tyre. Alternatively, tyres which during their manufacture have not been accepted because of quality factors could well be used to form a device of the invention.

The devices of the invention can be formed from various types of tyre in so far as the internal construction thereof is concerned. For example, tyres which do not involve metal cords, tyres with metal side wires, car tyres, lorry tyres, civil engineering vehicle tyres such as those of earth moving machinary.

If desired, the device of the invention can be especially moulded from plastics or rubber like materials to thereby provide structures in which the desired openings or recesses are formed during the moulding process. Conveniently such moulded devices can be formed with formations similar to conventional tyre treads so as to enhance the requisite grip afforded by the moulded devices.

In the cases of devices which are moulded it uill be understood that the device of the invention could be of such form as to be able to bridge a pair of sideby-side wheels such as are frequently provided upon commercial vehicles. In this case the device would have a tread portion of such width as to be able to bridge the distance between the outer wall of the tyre on the outermost wheel and the inner wall of the tyre on the inner wheel of a pair. The double tyre device can comprise two sets of lugs or flaps 14 each being genenally similar to those of the single tyre arrangement or, if thought desirable can be provided with a third set of centrally positioned lugs or flaps which co-operate with a ring member located between the adjacent pair of wheels and connected with one of the wheels. In this latter case an integral rib can be provided on the inside of the moulded device the rib running circumferentially around the device. This rib can be connected with the lugs or flaps. If it is considered that the extra set of lugs or flaps 14 is not necessary they can be dispensed with thereby leaving the rib as a convenient means for aiding in the positioning of the double width device in its desired position. Conveniently, the surface of the ring member

17 which is to face towards the tyre 2 can be provided with a dimpled surface or other form of roughening which does not present sharp edges to the tyre wall. It should be noted that in practice a ring member would be used at each side of the tyre.

Also it will be understood that if desired the ring members could be such as to be a permanent fixture on the wheels- particularly in the case of the inside face of the wheel. In the case of the front or outer face of the uheel the associated ring member could additionally form part of the visual design enhancements for the vehicle.

Reference will now be made to the Figure 4 which is a very schematic representation in part cross section of apparatus for removing areas of a tyre to provide the openings in a tyre and thereby to provide the device 7 of the invention.

The apparatus essentially comprises a punch assembly 26 mounted on the ram 27 of a pneumatically or hydraulically operated ram unit 28 which is carried by a support stand 29 for positional adjustment relative to a support base plate 30.

The punch assembly comprises a ring blade 31 having a cutting edge 32 shaped to provide the required shape of the aperture to be provided in the tyre to be converted into the tread portion of the device of the invention. The blade has a generally rectangular outlin with rounded corners and with opposed sides of the blade parallel to each other. The blade is held in place by a blade clamp ring 33 which clamps the blade to a chuck 34 mounted on the end of the ram 28 of the ram unit 29.

The punch assembly includes an ejector pin 35 which is resiliently loaded by a spring 36 and which is axially displacεable within a recess 37 provided in the chuck.

The ram is operable by means of a suitable control arrangement schematically shoun at 37A. It will be understood that the ram unit is connected with the appropriate sourceof pressurised fluid.

The blade 31 co-operates with a mandrel or bolster 38 which serves to support the tyre being modified, and has a blade receiving recess 39 into which the blade 31 may enter when the ram displaces the blade downwardly twowards the base plate 30 or mandrel 38.

A guard arrangement 40 is provided for protecting the operator from the blade. This guard is lowerable to contact the tyre by means of a handle arrangement which is schematically shown at 41.

In operation the tyre 1 is placed upon the mandrel 38 and is so positioned that the region of the tyre which is to be punched out is located immediately beneath the blade 31. The guard 40 is lowered to an extent that it pushes the tyre firmly against the mandrel that is flat against the mandrel. At this position the guard can be arranged to complete an interlocking arrangement included in the control of the ram unit which enables the control 37A to be operated to allow the blade to be driven downwards towards the mandrel and through the tyre to enter into the recess 39 in the mandrel. At the completion of this operating stroke the ram is caused to retract. This part of the operation can be automatic or operator controlled. The retraction of the ram allows the ejector pin to eject the piece of tyre removed from the tyre from the blade 31.

In a variation of the mandrel the arrangement can be such that the piece removed from the tyre is ejected through the mandrel.

It will be appreciated that the actual mode of operation of the ram assembly will depend upon the particular construction details of the ram assembly. Since ram assemblies and control systems therefore are well knoun further discussion thereof is not thought necessary.

After the ejection stroke of the ram the guard will be raised to release the tyre. It will be found that as soon as the pressure on the tyre is removed the tyre will resume its conventional shape, and that the walls of the opening formed by the removal of the piece of tyre material will be tapered inwards from the outer surface of the tyre to the inner surface of the tyre. In other words the parallel sided punch blade is able to produce the desired tapered wall formation to the openings.

Whilst the above description has been directly concerned with the formation of openings it will be understood that the provision of recesses with the tapered walls may be found to be sufficient to provide the required traction effect.

It will be appreciated that the lugs or flaps 14 are produced by removing material from the walls of the tyre being modified. Conveniently the flaps are formed before the punching out of the openings 9 so as to facilite the handling of the device during the hole punching operation.

Claims

CL AIMS

1. A method of providing the tyre of a vehicle wheel or the tyres of a double wheel assembly with a traction tread or flexible cover device, the method comprising the steps of shrouding the tread region (3) of the tyre or assembly (1) with a traction tread or flexible cover (7) which circumscribes the tread region (3) and which is provided with recesses or openings (9) in the part thereof that co-operates with the tread region (3) and securing the traction tread or flexible cover (7) in place by attachment arrangements (16,17) that co-operate with both the traction tread or cover and the wheel or wheel assembly.

2. A traction tread or cover device for shrouding the tread regions of the tyre of a vehicle wheel or the tyres of a double wheel assembly for a vehcile, the device being characterised by am endless track forming element (7) for circumscribing the treed region of the tyre or tyre assembly, and which is provided with recesses or openings (9) in the part (g) thereof that is intended to co-operate with the tread region (3) of the tyre or tyre assembly, and by attachment arrangements (16,17) for connecting. the element (7) to the wheel or wheel assembly (6).

3. A traction tread or cover device as claimed in claim 2, characterised in that the track forming element (7) comprises a conventional tyre whose tread portion has been part removed to provide said recesses or openings (9) and whose side walls have been adapted to co-operate with the attachment arrangements (16, 17).

4. A traction tread or cover device as claimed in claim 2 or 3, characterised in that attachment arrangements include a ring member (17) which is adapted to engage with the flange region of the wheel structure upon which the tyre is provided and also to engage with the tyre side wall (4) adjacent thereto.

5. A traction tread or cover device as claimed in claim 3 or claim 4 as appendent to claim 3, characterised in that the recesses or openings are so postioned in the element (7) that at least a part of the recesses or openings (9) extend to the shoulder region (13) between the tread region (8) and the side walls

(4) of the tyre from which the element is formed.

6. A traction tread or cover device as claimed in claim 4 or 5, characterised in that the attachment arrangements include a plurality of apertures (20) circumferentially spaced apart around the side wall of the tyre from which the element (7) is formed, and in that location means (16) are adapted to couple the side wall to the ring member (17)

7. A traction tread or cover device as claimed in any one of claims 2 to 6, characterised in that the walls of the recesses or openings (9) are inclined outwardly in the direction from the inside of the element (7) to the outside of the element.

8. A traction tread or cover device as claimed in claim 2, characterised in that the element (7) is dimensioned as to be able to bridge the separation between adjacent tyres of a double wheel assembly and in that the part (8) intended to coperate with the tread regions (3) is of such width as to bridge the distance between the outer wall of the tyre on the outermost wheel and the inner wall of the tyre on the inner wheel.

9. A method of producing the openings in a conveitional tyre for producing a device as claimed in any one of claims 2 to 7, characterised by. the steps of flattening the region of the conventional tyre from which a portion is to be removed to form the opening, punching out the portion by means of a cutter blade having a profile which defines the shape of the opening and which produces a wall to the opening which is not inclined and which deforms to an inclined form on allowing the flattened region to return to its initial form.