GB2033312A

GB2033312A - Pneumatic vehicle tyre

Info

Publication number: GB2033312A
Application number: GB7928767A
Authority: GB
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1978-08-19
Filing date: 1979-08-17
Publication date: 1980-05-21
Also published as: FR2433424B1; ATA430279A; DE2836352A1; AT371067B; IT7924580A0; FR2433424A1; IT1122281B; GB2033312B

Abstract

A pneumatic vehicle tyre is disclosed having two carcase plies (5, 6) in the side wall (7) of the tyre and a rubber layer (11) of low internal friction located between the pies. One carcase ply (6) is anchored in the tyre beads (9) by being looped around the bead cores (10) and extends to the associated tyre shoulder (8). The second carcase ply (5) extends from one tyre bead to the other, but is not anchored by its edges to the bead cores (10). The ply (5) thus terminates closely above the bead cores (10). <IMAGE>

Description

SPECIFICATION Pneumatic vehicle tyre The present invention relates to a pneumatic vehicle tyre having a rubber layer of low internal friction located between two carcase plies in the side wall of the tyre.

It is known in a twin-ply carcase tyre to arrange an intermediate layer of soft rubber between both carcase plies. A relatively good deformability of the side walls of the tyre is thus obtained even when the two carcase plies form intersection filament-like reinforcing plies.

Since with this tyre design the two carcase plies are passed continuously from one bead to the other, the aforesaid intermediate rubber layer is enclosed on all sides, thus on both sides and above and below by the carcase plies. This makes it impossible for a compensation of tension to occur between the two carcase plies, required mainly curing cambering.

The object of the present invention is to develop the above tyre in such a manner that both during tyre manufacture and during use of the pneumatic tyre a compensation of tension may occur between the two carcase plies.

According to the present invention there is provided a pneumatic vehicle tyre having a rubber layer of low internal friction located between two carcase plies in the side wall of the tyre, in which one carcase ply of the tyre side wall is anchored in the tyre beads by being looped around the bead cores and extends to the associated tyre shoulder, whilst the second carcase ply extends continuously from one tyre bead to the other tyre bead, but is not anchored by its edges to the tyre bead cores.

Thus it can be seen that a carcase ply is used in accordance with the invention which extends from one bead to the other but which is not anchored by its edges to the tyre bead cores. Moreover, the other carcase ply, located in each side wall of the tyre is anchored with its radially internal end in the tyre beads by being looped around the bead cores, whilst the radially external end of such carcase ply terminates substantially in the region of the associated tyre shoulder. Consequently, although a carcase ply is provided which extends from one bead region to the other, such ply is not, however, anchored by being looped around the tyre bead cores. The other carcase ply forming the second ply in the side wall of the tyre, on the other hand is anchored in the tyre beads, but extends only to the shoulder portion of the tyre.

By such an arrangement and development of the carcase plies on the one hand the said intermediate rubber layer comes fully into play because the rubber layer is not enclosed on all sides; on the other hand the two carcase portions anchored in the tyre beads may be mutually displaced relative to each other both during the cambering and during operation of the tyre. A compensation of tension occurs, so as not to stress the individual reinforcing members excessively and consequently to provide uniformity of stress to all reinforcing members.

Furthermore, a bending body is now provided also in the side walls of the tyre which due to the mutual displaceability of the carcase portions results in a relatively greater flexibility.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawing in which the single Figure shows a radial part section through a pneumatic vehicle tyre in accordance with the present invention.

The tyre body 1, comprised substantially of rubber or rubber-like material, has a tensionresistant belt 3 located below its tread strip 2, which belt extends substantially over the width of the tread strip 2.

Both the belt 3 and the carcase 4 are comprised of tension-resistant filaments or wires located in cord ply and which are embedded in rubber or rubber-like material. This tyre cord fabric forms an outer ply 5 and two further plies 6 for each tyre side wall 7. The plies 6 which face the tyre cavity extend from the tyre shoulder 8 radially inwards along the inner surface of the tyre side 5.

Here they are anchored in the beads 9 by being looped around the bead cores 10. The ply 5 on the other hand extends from one bead 9 to the other bead 9, thus it is not interrupted, but it is also not anchored at the bead cores 10; the edges of ply 5 thus terminate closely above the bead cores 10.

In the side walls 4 of the tyre between the two plies 5 and 6 there is a soft rubber layer 11 substantially of crescent-shaped cross-section which over half the height of the two side walls 4 has maximum wall thickness and in the region of the tyre shoulder 8 and closely above the tyre core 10 has acutely tapering edges 12. The rubber layer 11 is adhesively connected to the two plies 5, 6. It has a lower internal friction and is relatively soft in order so to provide relatively soft, readily bending tyre side walls 4.

Substantially halfway up the two tyre side walls 4, the rubber layer 11 has a wall thickness which is greater by twice to six times, preferably three to four times, than the diameter of the reinforcing members which, in parallel arrangement, form the plies 5 and 6.

The invention is preferably used in combination with those carcases in which the reinforcing members of one ply rise in one diagonal direction and the reinforcing members of the other carcase ply rise in the opposite diagonal direction, namely by forming a preferably symmetrical cross carcase of known structure.

The fact that the plies 5 and 6 in the tyre side walls are interconnected over their entire height substantially only by the rubber layer 11 is favourable only because mutual compensation movements of the plies 5 and 6 are possible. The rubber layer 11 may thus be stressed readily by corresponding loading of the plies 5 and 6 for shear, but also with little resistance to bending.

Claims

1. A pneumatic vehicle tyre having a rubber layer of low internal friction located between two carcase plies in the side wall of the tyre, in which one carcase ply of the tyre side wall is anchored in the tyre beads by being looped around the bead cores and extends to the associated tyre shoulder, whilst the second carcase ply extends continuously from one tyre bead to the other tyre bead, but is not anchored by its edges to the tyre bead cores.

2. A pneumatic vehicle tyre as claimed in claim 1, in which the rubber layer between the two carcase plies has a substantially crescent-shaped cross-section in such a manner that the maximum wall thickness corresponds from twice to six times the diameter of the reinforcing members forming the side walls of the tyre.

3. A pneumatic vehicle tyre as claimed in claim 1 or 2, in which the two plies in the side walls of the tyre have reinforcing members formed in the manner of a cross carcase.

4. A pneumatic vehicle tyre as claimed in claim 1, 2 or 3, in which the rubber layer at its outer edge terminates in the region of the outer edge of the carcase ply and at its inner edge terminates at the inner edge of the other carcase ply.

5. A pneumatic vehicle tyre, substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.