GB2038248A

GB2038248A - Tyre crown reinforcements

Info

Publication number: GB2038248A
Application number: GB7936440A
Authority: GB
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1978-11-04
Filing date: 1979-10-19
Publication date: 1980-07-23
Also published as: IT7922920V0; IT7926670A0; FR2440838B1; IT1124633B; DE2847926A1; GB2038248B; FR2440838A1

Abstract

A radial tyre has a belt (5) whose edges are reinforced by members (9) each having filaments (13) which intersect one another at an angle of substantially 90 DEG and which each lie at an angle of from 30 to 60 DEG , preferably 45 DEG , to the circumferential direction of the tyre. Each member (9) may be a single ply structure comprising an integral network of filaments (13) as shown in Figure 3, or may be formed by two superposed and cross-laid cord plies. The belt (5) may as shown comprise two plies (6), (7) with cords at 18-25 DEG to the circumferential. <IMAGE>

Description

SPECIFICATION Pneumatic vehicle tyre The present invention relates to a pneumatic vehicle tyre having a belt which extends substantially over the width of the tread strip and is located between the carcase and the tread strip, the edges of the belt being enclosed by strips made of filament-like reinforcing plies.

It is known, in connection with belted tyres having a coarse-studded tread surface profile, to enclose the edges of the belt with additional reinforcing plies.

These strip-like reinforcing plies are comprised of filaments extending in the circumferential direction of the tyre and are made of a heat-shrinkable material, e.g. a polyamide, polyester or polyvinyl alcohol. These reinforcing plies have as object the prevention of unevenesses in the tyre surface and structural changes of the tyre, when the tyre surface, on account of its coarse-studded profile, is embossed or impressed.

These reinforcing plies, however, only have a limited resilient deformability in the circumferential direction of the tyre; moreover the necessary diameter increase at the edge of the belt during production of the tyre is prevented. Accordingly, in the completed, vulcanized tyre, the travelling and abrasion behaviour of the tyre is affected due to the greatly different deformation behaviour between the belt edge an the belt centre.

It is an object of the invention to at least minimize these deficiencies. Hence a tyre is to be provided which, during its production and preferably in the region of its belt portion, still permits minor dia meter increases. It is also desired to produce a belted tyre in which securing of the belt edges is effected, whilst, at the same time, a resilient deformability is obtainable in the crown portion of the tyre to an increased extent, without having to be concerned regarding the occurrence of separation phenomena in the region of the belt edges.

In accordance with the present invention there is provided a pneumatic vehicle tyre having a belt which is tension-resistant in the circumferential direction of the tyre, extends substantially over the width of the tread strip, and is located between tread strip and the carcase, which belt produces lateral stabilisation of the tyre, the edges of the belt being enclosed by strips made of filament-like reinforcing plies, in which the reinforcing plies of the strips intersect at an angle of substantially 90 , whilst they also obtend an angle of from 30 to 60 with the circumferential direction of the tyre.

Preferably, the reinforcing plies obtend an angle of 45" with the circumferential direction of the tyre.

These reinforcing plies may be formed by two superposed cord fabric plies, preferably, however, a lattice-like structure of filament-like reinforcing plies is used, in which the reinforcing plies are securely interconnected at the intersections, e.g. by mutual penetration or welding.

This as such solid lattice-like reinforcing element therefore permits a relatively high resilient deforma tion to occur, because the filament-like reinforcing plies extend at the aforesaid relatively large angles to the circumferential direction of the tyre. Thus, a diamond displacement may occur as is known in diamond bracing in tyre construction. This deformability also permits the individual strips during the tyre fashioning or during the winding onto the tyre blank to be deformed in the required manner, to allow the strip then to be placed flush onto underlays of the tyre blank which deviate from a cylindrical shape to a considerable extent.

The present invention will be further illustrated, by way of example, with reference to the accompanying drawings, in which: Figure lisa radial part section through a pneumatic vehicle tyre; Figure 2 is a partial plan view of the reinforcement of the tyre body located between the tread strip and carcase of the tyre; and Figure 3 is a partial elevation from the enlarged diagrammatic view shown in Figure 2.

The tyre body, comprised of rubber or rubber-like materials, is reinforced by a radial carcase 1, the edges of which are anchored by being looped around bead cores 2 in the tyre beads 3.

A belt 5 made of parallel rubberised and tensionresistant filaments, preferably steel wires, is provided between the tread strip 4 and the carcase 1 and extends substantially over the width of the tread strip 4. As illustrated, the belt 5, is formed of two superposed plies 6,7 arranged in such a manner that the steel wires 8 of both plies 6,7 intersect and in symmetrical arrangement each obtend an angle a of from 18 to 250 with the circumferential direction of the tyre.

The edges of the belt 5 are enclosed bandage-like strips 9 which in Figure 1 are shown by broken lines.

These strips 9 have a width of about 1/8th to 1/5th of the width of the belt 5; their laterally outward edge 10 is located on half the spacing A between the two edges 11, 12 of the two plies 6, 7.

The strips 9, which are single ply in accordance with the embodiment, comprise tension-resistant filaments 13, e.g. of artificial silk intersecting at an angle of substantially 90". These filaments 13, however, are not located in the manner of a solid fabric with crimp, thus in the region of the intersections mutually considerably displaceable, but are substantially non-displaceably interconnected at the intersections 14, which interconnection may be obtained by mutual penetration ofthefilaments 13, or by welding. The filaments 13 each obtend an angle of approximately 45" with the circumferential direction of the tyre.

Consequently, the steel wires 8 extend at a substantially smaller angle relative to the circumferential direction of the tyre than the filaments 13.

Moreover, they are not laid in two plies one above the other, but substantially in a plane or a ply, so that a sufficiently resilient elongation of the strips 9 may occur once in circumferential direction and then also with local deformation, in that the angles between intersecting filaments 13 change in a "lazy-tong" manner. These strips thus have a favourable effect on the edge regions of the belt 5. They quieten down the freely extending edges, prevent separation phe nomena whilst still permitting adequate deformations. Since the strips 9 are made predominantly of artificial silk or any similar soft material, they form, from both strength and dynamic aspects, favourable transition between the relatively rigid belt edges and the rubber plies of the tread surface edge portions located thereabove.

This deformability, however, is also useful in tyre manufacture. During production of tyres it permits diameter changes of the tyre in the crown portion e.g. when the still unvulcanized tyre blank is to be profiled under a certain diameter increase at the outer circumference and thus is to be moulded.

Claims

1. A pneumatic vehicle tyre having a belt which is tension-resistant in the circumferential direction of the tyre, extends substantially over the width of the tread strip, and is located between tread strip and the carcase which belt produces lateral stabilisation of the tyre, the edges of the belt being enclosed by strips made of filament-like reinforcing plies, in which the reinforcing plies of the strips intersect at an angle of substantially 90 , whilst they also obtend an angle of from 30 to 60 with the circumferential direction of the tyre.

2. A pneumatictyre as claimed in claim 1, in which the reinforcing plies obtend an angle of 45" with the circumferential direction of the tyre.

3. A pneumatic tyre as claimed in claim 1 or 2, in which the reinforcing plies form single ply strips, and at their intersections are non-displaceably connected to each other.

4. A pneumatic tyre as claimed in claim 3, in which the reinforcing plies at their intersections are non-displaceably connected to each other by mutual penetration or welding.

5. A pneumatic tyre as claimed in any preceding claim, in which in a double ply belt stepped at its edges, the laterally outside edge of the strips terminates substantially at half the spacing between the two edges of the two plies.

6. A pneumatic tyre, as claimed in any preceding claim, in which the width of the strips corresponds from 1/5th to 1/8th of the belt width.

7. A pneumatictyre as claimed in any preceding claim, in which the reinforcing plies of the strips are made from textile material, such as artificial silk, whilst the belt plies are comprised of steel wires or reinforcing members of a similarly high tension resistance and bending resistance.

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