GB2035228A

GB2035228A - Pneumatic vehicle tyre

Info

Publication number: GB2035228A
Application number: GB7931350A
Authority: GB
Original assignee: Continental Gummi Werke AG
Current assignee: Continental AG
Priority date: 1978-09-11
Filing date: 1979-09-10
Publication date: 1980-06-18
Also published as: IT7924897A0; IT1122408B; DE2839450A1; ATA517379A; FR2435359A1; FR2435359B1; AT375306B; IT7922278V0; GB2035228B

Abstract

To strengthen a pneumatic vehicle tyre having a single-ply radial carcase in the bead region, a strip (12) formed of tension-resistant filaments or the like extends parallel to a bead reinforcing member (8) and overlaps the free end of the member (8), whilst the filaments or the like obtend right angles or substantially right angles with the circumferential direction of the tyre. The member (8) comprises parallel cords making an angle of 15 DEG -45 DEG with the circumferential direction. The strip (12) is axially outwardly or inwardly of the member (8), and may be associated with a second strip (11), or the strip (12) may be folded to envelope the member or member and carcase ply end (5). <IMAGE>

Description

SPECIFICATION Pneumatic vehicle tyre The present invention relates to a pneumatic vehicle tyre having a single ply radial carcase formed of steel or any like material of similar strength, whereby the carcase, by enveloping the bead cores, is anchored in the beads and the laterally external free edges of the carcase ply can extend to about half-way up the height of the side walls of the tyres, whereby laterally externally adjacent to the enveloped carcase end, a bead reinforcing member is provided comprised of parallel tension-resistant filaments or the like which extends diagonally with reference to the carcase, preferably at an angle of from 15 to 45" relative to the circumferential direction of the tyre, whereby the bead reinforcing member has associated therewith a strip formed of cord ply tension-resistant filaments which overlaps the free end of the bead reinforcing member.

In known pneumatic vehicle tyres of this kind the filaments or the like forming this strip obtend with the circumferential direction of the tyre angles which also are from 15 to 45 , but are located diagonally opposite with reference to the tension-resistance filaments or the like of the bead reinforcing member.

By means of the arrangement of the filaments of the bead reinforcing member and the filaments of the aforesaid additional strip, there is formed in combination with the reinforcing member of the carcase a triangular bracing which leads to a desirable bracing and releaving of the bead portion of the tyre. This development also has the advantage that separation phenomena in the carcase edge and the bead reinforcing member are prevented. Nevertheless, due to the inevitable damage stresses, there is the danger that the rubber located between the bead reinforcing member and the radially outwardly located end of the carcase edge is excessively stressed and can be damaged thereby.

It is an object of the invention to improve the above-mentioned tyre in such a manner that the said advantages are obtained and the risk of damage to the aforesaid rubber layers is prevented.

According to the present invention there is provided a pneumatic vehicle tyre having a single-ply radial carcase formed of steel or any like material of similar strength, the carcase being anchored in the beads by wrapping around the bead cores and the laterally external free edges of the carcase ply extending up to about halfway up the side walls of the tyre, whereby laterally of the enveloped carcase end, a bead reinforcing member comprised of parallel tension-resistant filaments orthe like is provided which extends diagonally with reference to the carcase, preferably at an angle of from 15 to 45" relative to the circumferential direction of the tyre, whereby the bead reinforcing member has associated therewith a strip extending parallel thereto formed of cord ply tension-resistant filaments orthe like and overlapping the free end of the bead reinforcing member, in which the tension-resistant filaments or the like forming the strip obtend right angles or substantially right angles with the circumferential direction of the tyre.

Thus it can be seen that the filaments of the strip are hence aligned substantially parallel in the wires or the like of the carcase.

This arrangement permits a better deformation property of the bead portion to be obtained in the circumferential direction of the tyre. There is not formed a substantially non-deformable triangle bracing, but a diamond structure, which permits circumferential deformations at the point of contact with the ground.

The present invention will be further illustrated by way of example with reference to the accompanying drawings in which several embodiments are shown, of which the embodiment of Figure 1 is of particular advantage, and in which: Figure 1 is a radial part section through a pneumatic vehicle tyre in the form of a belted tyre in accordance with the present invention; Figure 2 shows the bead portion of the tyre of Figure 1 on an enlarged scale; Figure 3 shows the bead portion of Figure 2 in side elevation, and thus seen laterally from the outside, whilst stressing the reinforcing member contained in the bead of the tyre; and Figures 4 to 8 each show views similar to Figure 2 and hence are part sections through a pneumatic vehicle tyre in the region of a tyre bead, illustrating different embodiments in accordance with the invention.

As illustrated, a pneumatic vehicle tyre is formed substantially of rubber or rubber-like materials and has a radial carcase 1 comprised of steel wires 2, which wires extend at right angles to the circumferential direction of the tyre. The steel wires 2 are anchored in the tyre beads 3 by wrapping the ends thereof around the tension-resistant steel bead cores 4. The laterally external folded-over part of the carcase is denoted by the reference numeral 5, the edge of the carcase wrap-over by the reference numeral 6.

Between the carcase 1 and the tread strip which has a tread surface profiling, a tension-resistant belt 7 is provided on the outer circumference of the tyre extending substantially over the width of the tread strip, which belt strengthens the crest portion of the tyre and provides the carcase 1 with lateral stability.

A bead reinforcing member 8, formed of rubberised mutually parallel, tension-resistant steel wires 9 which obtend angles of from 15 to 45" with reference to the circumferential direction of the tyre is provided laterally externally adjacent to the folded over part 5. The bead reinforcing member8 is placed around the bead cores 4 and overlaps the edge 6 of the folded over part 5 of the carcase 1. In accordance with Figure 2, the folded over part 5 and the laterally external section of the bead reinforcing member 8 are located between two rubberised cord fabric plies 10, 11, which form endless strips 12 extending over the circumferential direction of the tyre. The strips 12 formed of the two cord fabric plies 10 and 11 have mutually parallel filaments or fibres 13 formed of polyamide or the like.On the outer circumference, the strips 12 are close to each other. They increase their mutual spacing as they approach the bead cores 4 and thus enclose the folded over part 5 and the laterally external section of the bead reinforcing member 8 between them. Between the folded-over part 5 and the bead reinforcing member 8 in the region oftheirfree edges at 14, a spacing is obtained by the addition of a rubber strip, so that no absolute parallelity is provided. However, it is important that the filaments or fibres 13 follow the course of the radial carcase 1, thus extending at right angles or substantially at right angles to the circumferential direction of the tyre.Of the filament-like, tensionresistant reinforcing plies provided in the bead portion, only the reinforcing plies of the bead reinforcing member 8 extend at the aforesaid angle of from 15 to 45" relative to the circumferential direction of the tyre. Due to this - as shown at 15 - a diamond bracing is formed which, at the point of contact with the ground, permits sufficiently great deformations without, however, neglecting their object of producing considerable bracing. The reinforcing membersofthecarcase 1 and the strip 12 thus extend parallel and only the elements of the bead reinforcing members 8 have a diagonal extension.

The diamond formation at 15 not only avoids separation phenomena in the region at 14, but, moreover, also excessive shearing stress by resilient deformation in the region of the intermediate rubber plies is avoided.

In the embodiment shown in Figure 4, only one strip 12 extending as shown in Figure 3 is provided.

It extends radially outwards substantially from the lower edge of bead core 4 to far beyond the free end of the bead reinforcing member 8.

The embodiment of Figure 5 also provides for only one strip 12 with the said filament course; however, the strip 12 is folded over so that its fold position 16 is located on the outer circumference, whilst the two shanks 17 and 18 enclose the folded-over part 5 and the bead reinforcing member 8.

Between the folded-over part 5 and the bead reinforcing member 8, as shown in Figure 6 a ply of a polyamide cord fabric is located, and thus also in conformity with Figure 4, only one strip 12. This strip 12 thus passes through the rubber layers at 14.

The embodiment of Figure 7 uses two strips 12, which extend substantially parallel to each other and between them enclose the carcase ply 1 in the region of the bead cores 4 and the folded-over part 5. The two free ends of the strips, however, overlap the radial outer end of the bead reinforcing member 8.

In the bead configuration of Figure 8, the strip 12 is doubled by folding. The shanks 17 and 18 formed herein only enclose the laterally external part of the bead reinforcing member 8.

Claims

1. A pneumatic vehicle tyre having a single-ply radial carcaseformed of steel or any like material of similar strength, the carcase being anchored in the beads by wrapping around the bead cores and the laterally external free edges of the carcase ply extending up to about halfway up the side walls of the tyre, whereby laterally of the enveloped carcase end, a bead reinforcing member comprised of parallel tension-resistant filaments or the like is provided which extends diagonally with reference to the carcase, preferably at an angle of from 15 to 45" relative to the circumferential direction of the tyre, whereby the bead reinforcing member has associated therewith a strip extending parallel thereto formed of cord ply tension-resistant filaments or the like and overlapping the free end of the bead reinforcing member, in which the tension-resistant filaments or the like forming the strip obtend right angles or substantially right angles with the circumferential direction ofthetyre.

2. A pneumatic vehicle tyre as claimed in claim 1, in which the tension-resistant filaments or the like of the strips with adjacent reinforcing plies of the carcase and the bead reinforcing member form deformable diamond bracings.

3. A pneumatic vehicle tyre as claimed in claim 1, in which the folded over part of the carcase and the laterally external section of the bead reinforcing member are located between two strips.

4. A pneumatic vehicle tyre as claimed in claim 3, in which the two strips enclose between them either the laterally external region of the bead reinforcing member or the folded over part of the carcase.

5. A pneumatic vehicle tyre as claimed in any preceding claim, in which the strip sections at the radially external edge merge intergrally with each other forming a substantially U-shaped crosssection.

6. A pneumatic vehicle tyre as claimed in claim 1, in which only a single ply strip is provided, which is located laterally outwards adjacent to the bead reinforcing member and the folder over edge part of the carcase.

7. A pneumatic vehicle tyre as claimed in claim 1, in which the radial overlap of the strip opposite the laterally external section of the bead reinforcing member substantially corresponds to the radial spacing between the radially external edges of the bead reinforcing member on the one hand and the folded over part of the carcase on the other hand.

8. A pneumatic vehicle tyre as claimed in claim 1, in which the sections of the strips located on the outer circumference and the folded over part of the carcase are spaced apart by interposition of a rubber layer.

9. A pneumatic vehicle tyre as claimed in claim 8, in which the strips pass through the regions of greater mutual spacing.

10. A pneumatic vehicle tyre as claimed in claim 1, in which ends of the strips located at the inner circumference partly enclose the bead cores.

11. A pneumatic vehicle tyre as claimed in claim 10, in which the strips in the region of the bead cores enclose between them the ply of the carcase.

12. A pneumatic vehicle tyre as claimed in claim 7, in which the radial overlap substantially corresponds to the radial overlap of the folded over part of the carcase opposite the outer circumference of the bead core.

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