A VEHICLE AND TIRE THEREFOR

Abstract: A pneumatic tire (T) having bead portions reinforced by a respective bead core (18(19) and a bead reinforcing ply (15) (16). The bead reinforcing plies have cords (21) therein that are substantially parallel to each other and are arranged so that the cords (21) in one reinforcing ply (15) are substantially parallel to the cords (21) in the other ply (16). A direction mark (23) is located on an external surface of the tire to show the direction of the reinforcing cords (21) in relation to the rota­ tional direction of the tire. When such tires are mounted on the axle unit they may be arranged so that the direction marks are pointed all in the same rotational direction,

Description: This invention relates to vehicles and to tires therefore. It is known to produce vehicle tires with bead reinforcing plies or strips comprising rubberized cord material, wherein the cords are arranged to be parallel to one another in corresponding parts of the two beads. Thus, if one were able to see into such a tire, on looking at one side the cords would extend diagonally to the bead core in one sense, e.g. top left to bottom right, whereas on the other side of the tire, the cords would extend diagonally in the opposite sense, i,e. top right to bottom left. Such a tire is illustrated in GB 1 439 962. This means that during tine building of such tires the cards of the bead reinforcing plies have to be positioned in opposing senses as can be seen in Figure 3. The reason for this construction is to reduce the possibility of any unwanted bias effects occurring in the tire which would lead to adverse tire performance. However, when more than one tires is mounted on the same axle, or on aligned stub axles on opposite sides of the vehicle further unwanted bias effects can also arise if the bead reinforcing ply cord direction is arranged randomly. It is also an object of the present invention to attempt to put these effects to useful purpose. A tyre according to the preamble of claim 1 is proposed in EP-A-0194070 (cited under Art. 54(3) EPC, published 10.09.86). The present invention has the features recited in the independent claim 1. There is also provided a vehicle with at least two tire and wheel assemblies positioned in use one on each side of the vehicle, each tire of said assemblies being of the type described above characterised in that the tire and wheel assemblies are mounted on the vehicle so that the respective direction arrows on the tires all point in the same rotational direction. Two assemblies may be mounted on a single axle extending across the vehicle, or alternatively on a pair of stub axles, one on each side of the vehicle. It may also be advantageous not only to mount the tires on the vehicle with the ply cords in a a single direction of rotation but in a predetermined relationship with respect to the direction of forward travel of the vehicle. The direction arrows on the tires for use on such vehicles indicate the bead reinforcing ply cord direction to prevent misfitting of such tires on the vehicle. One embodiment of the invention will now be described by way of example only with reference to the accompanying drawings of which: Figure 1 shows an exploded view of part of a radial ply tire according to this invention. Figure 2 shows a vehicle axle unit, and Figure 3 shows a partial plan view of the tire of Figure 1 during building. As shown in Figure 1 a radial ply tire T comprises a ground contacting tread 10 having a pair of sidewalls 11 (only one of which can be seen in Fig 1) extending radially inwards thereof. The tread 10 and sidewalls 11 are respectively reinforced by two concentric breakers 12 and 13 and a radial carcass ply 14. By radial carcass is meant, a carcass the reinforcing cords of which make an angle of between 70 and 90 degrees to the direction of rotation of the tire. The inner end portions of the sidewalls 11 terminate in respective portions reinforced by a bead core 18 or 19 which are further reinforced by a bead reinforcing ply 15 or 16. An inner liner 17 of halobutyl rubber helps prevent air permeating through the body of the tire. The two bead reinforcing plies 15 and 16 are annular strips and are located one in each bead portion and are wrapped around the respective bead cores 18 and 19 within the radially inner portions of the carcass ply 14 and their respective turnups 20 which are wrapped around the bead cores 18 and 19 from the inside to the outside. The reinforcing cords 21 in each reinforcing ply 15 and 16 are substantially parallel to each other. As can be seen in Figure 1, bead reinforcing ply cords 21 extend at an angle of approximately 60 degrees with respect to the cords 22 of the radial ply carcass 14, the cords in one reinforcing ply being substantially parallel to the cords in the other reinforcing ply. The plies are of conventional construction each being of suitable cord Material, e.g. steel or textile, encased in elastomeric material. The tire is marked on the external surface thereof in the lower sidewall region with a ply direction mark 23 to indicate the direction of the cords 21 of the bead reinforcing plies with respect to a relative rotational direction of the tire when mounted on a vehicle and during forward movement of the vehicle. In this example an arrow is illustrated but other direction markings may be used. During the construction of such a tire the reinforcing plies are arranged so that the cords extend in opposite senses as can be seen in Figure 3 which shows a plan view of part of the tire of Figure 1 during building on a "flat" building drum. When such two tires T1 and T2 are mounted on a vehicle axle unit 24 it is arranged that the cords of the reinforcing plies 15, 16 extend in the same direction as each other and preferably so that the direction marks on the tires T1 and T2 point in the same direction of rotation relative to the tire. This is illustrated simply in Figure 2, which shows two wheel (W1, W2) and tire (T1, T2) assemblies mounted on a single axle, one at each end. The tire and wheel assemblies can alternatively be mounted on a pair of stub axles on opposite sides of the vehicle, and which are preferably aligned with each other. If two tire and wheel assemblies in accordance with the invention are mounted on an axle on one side of the vehicle and two further tire and wheel assemblies in accordance with the invention, are mounted on an aligned axle on the other side of the vehicle, then the cords of the reinforcing plies in corresponding tires are arranged to be parallel to one another, for example, the bead reinforcing ply cords on the innermost two of each pair of tires are parallel to each other and the cords in the outermost two of each pair of tires are arranged to be parallel to one another. Preferably the cords of all four tires extend in the same direction. If it is desired to obtain a particular bias effect, for example when the tires are used on a racing car which continuously circuits a track in the same direction, then it may be desirable to mount the tires on the vehicle so that the direction marks on the tires on one side of the vehicle point in the opposite direction to the direction marks on the tires on the other side of the vehicle.

Claims: 1. A pneumatic tire (10) having a pair of bead portions each of which is reinforced by a bead core (18, 19) and at least one bead reinforcing ply (15, 16) having bead reinforcing cords (21) that are substantially parallel with each other, the cords (21) of the reinforcing ply (15) in one bead portion extending diagonally to the respective bead core (18) in an opposing sense to the cords (21) of the reinforcing ply (16) in the other bead portion so that the cords (21) of the reinforcing ply (15) on the axial outer side of said one bead core (18) extend diagonally in the same sense relative to the direction of rotation of the tire as the cords (21) of the bead reinforcing ply (16) on the corresponding axial outer side of said other bead core (19), said tire (10) having a direction mark (23) on an external surface thereof which relates to the direction of the cords (21) of the bead reinforcing plies (15, 16) on said axial outer sides of the bead cores (18, 19), characterized in that said direction mark is an arrow (23) near the bead portion, which arrow is parallel to and points into the diagonally extending direction of the cords (21) of the reinforcing plies (15, 16). 2. A pneumatic tire as claimed in Claim 1, characterised in that the cords (21) of said reinforcing ply (15) on said axial outer side in one bead portion are substantially parallel to the cords (21) in said reinforcing ply (15) on said axial outer side in the other bead portion. 3. A vehicle having at least two tire wheel assemblies (T1 W1 T2 W2) positioned in use, one on each side of the vehicle, each tire (T1 T2) of said assemblies being a tire as claimed in Claim 1 or Claim 2, the vehicle being characterised in that the tire and wheel assemblies (T1 W1, T2 W2) are mounted on the vehicle so that the respective direction arrows (23) on the tires (T1, T2) all point in the same rotational direction. 4. A vehicle according to Claim 3, characterised in that two tire and wheel assemblies (T1W1, T2W2) are mounted on a single axle (24) extending across the vehicle. 5. A vehicle according to Claim 3, characterised in that two tire and wheel assemblies (T1W1, T2W2) are mounted on a pair of aligned stub axles, one on each side of the vehicle. 6. A vehicle having four tire and wheel assemblies (TW) located one at each corner of the vehicle, each tire (T) of said assemblies being a tire as claimed in Claim 1 or Claim 2, characterised in that said tire and wheel assemblies are arranged so that the direction arrows (23) on the respective tires (T) on one side of the vehicle all point in one direction of rotation of the tires, and the respective direction arrows (23) on the tires (T) on the other side of the vehicle all point in the opposite direction of rotation of the tires.

Inventors: MCGLASHEN, JAMES NEIL
Applicants: APSLEY METALS LIMITED
Application year: 1986
Main classification: B60C15
IPC codes: B60C13, B60C15