DE3135870A1 - Method for the production of wire cores - Google Patents

Abstract

The invention relates to a method for the production of wire cores, particularly for vehicle tyres. In this method, a wire core is produced by winding rubberised wires spirally around one another in several layers. The radially outer overlapping end is brought to the outer circumference of the wire core, and it is proposed to secure this end on the remainder of the wire core by means of a knotted filament.

Description

description

The invention relates to a method for producing wire cores, especially for vehicle tires with rubberized wires in several layers in a spiral shape are wound over each other and in which the overlapping end of the radially outer Position brought up to the outer circumference from a tangentially protruding direction and then attached there, as well as a pneumatic vehicle tire using this method manufactured wire cores.

As is well known, 3 wheel cores serve to give a tire a tensile strength in the bead area to lend and to keep it on the rim. They are made of several rubberized Coiled steel wires. In the case of a conventional car tire, there is a wire core in the cross section e.g.

from 4 X 4, i.e. 16 wires. To produce a cross-section rectangular wire-rubber strip with four adjacent wires in four Layers wound spirally on top of each other and the outer end on the rest of the wire core body attached.

For a rational mass production, it is necessary to fasten the outer ends in the shortest possible time. In a known method the end is fastened in such a way that in the area of the overlap of the layers a rubber strip is manually placed around the wire core.

This known method has the major disadvantage that at a complete concern of the outer layer of the wire strip does not guarantee him is. The end can stick out due to the bending stiffness of the steel wires either caused by the fact that already when placing the rubber strip the end of the layer was not completely pressed or because of the subsequent storage or in the further production stages of a tire (manufacture, Vulcanization) because of the outward force and the elasticity of the applied Rubber strip lifts the outer layer in the end area from the underlying layer. A but such a take-off has result in such an area the tensile strength of a wire core is essentially only three layers of the wire core is determined so that a security risk may arise.

The invention is therefore based on the object of specifying a method in which the outer end of an epirally wound wire core is reliable and can be quickly attached to the rest of the wire core body.

According to the invention, this object is achieved in that the fastening is carried out by means of a knotted thread.

A vehicle tire with wire cores manufactured using this process is characterized in that the overlapping end of the radially outer layer means a knotted thread is attached to the rest of the wire core.

Compared to the known method, the invention offers the additional The advantage of this is that the fastening thread is uniform on all sides When knotting, a regular superposition of the individual wire core layers is guaranteed is, so that a lateral shift in particular the outer layer is excluded is. This results in a more uniform mass distribution in the wire core according to the invention and consequently also achieved with vehicle tires equipped therewith.

Advantageous refinements of the invention are set out in the subclaims refer to.

An exemplary embodiment of the invention is described below and explained with reference to a drawing.

It shows Fig. 1 a wound from a strip Wire core before completion (schematic), part of a Fig. 2 a vehicle tire in a side view with a partially exposed wire core, FIG. 3 shows a partial section through the tire according to FIG. 2.

For the production of a wire core with a cross section of 4 x 4 steel wires may have, a cross-sectionally rectangular wire-rubber strip with four steel wires embedded next to each other in a known manner on a core winding machine wound spirally to a wire core ring and cut to length in such a way, that the finished core ring has four adjacent layers and one overlap piece has five layers of approx. 70 mm in length.

Then the outer end of the wrapped wire-rubber strip, which, due to the bending stiffness of the steel wires, strives to become tangential Turn off the direction of the circumference of the core ring, drawn to the circumference and in the Overlap area wrapped with a thread and knotted.

Bringing up the free end and attaching and knotting the The thread is preferably done as part of an automatic manufacturing process, however, a knotting device known per se can be used also accessible for manual processing if required.

The thread is preferably in the part of the overlap area that comes closest to the outer end of the layer, e.g. in the first third this area.

So that when attaching and knotting the thread none in relation to the Mid-plane of the core asymmetrical forces can occur, the a lateral shifting of the layers, especially the upper ones, could result, the knot is preferably attached radially outside or radially inside of the wire core.

The thread can consist of a textile or metallic material, However, this should be as low-stretch as possible. Of the synthetic fibers, Kevlar is special well suited. Narrow strips of fabric can also be selected as threads, but they are must be knotable.

The wire cores produced by the process of the invention can can be used with pneumatic vehicle tires as well as with full rubber tires.

The wire core 1, which is still incomplete according to FIG. 1, is after its completion integrated into a pneumatic vehicle tire 2 according to FIG. 2 and is used there in a known manner Way to build a tire bead.

By knotting the outer layer 3 with the other parts of the Wire core by means of a thread 4 is a uniform and complete contact of all layers 3t 5, 6, 7 achieved, also during the manufacture and vulcanization of a tire is retained, so that in the finished tire 2 all four core layers 3, 5, 6, 7 participate over their full extent in the tensile strength of the entire core 1.

In Fig. 3 is a section through the core 3 according to FIG. 2 frame provides, namely in the overlapping area of the core layers, so the five superimposed Layers 3, 5, 6, 7, 8 can be seen.

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Claims (6)

Claims method for producing wire cores, in particular for Vehicle tires in which rubberized wires are wound in several layers in a spiral shape and in which the overlapping end of the radially outer layer consists of a tangential protruding direction brought up to the outer circumference and then attached there is, characterized in that the attachment by means of a knotted thread is carried out. 2 The method according to claim 1, characterized in that the thread applied in the front third of the radially outer overlapping end of the layer will. 3. The method according to claim 1, characterized in that a fastening thread is used, which is made of a low-stretch textile or metallic material consists. 4. The method according to claim 1, characterized in that the material Kevlar is used for the fastening thread. 5. The method according to claim 1, characterized in that the thread is attached by means of an automatic knotting device. 6. Vehicle tires with wire cores according to the method of claim 1, consisting of rubberized wires arranged in several layers in a spiral shape exist, characterized in that the overlapping end of the radially outer layer (5) is attached to the rest of the wire core by means of a knotted thread (4).