DE2442401C3 - Rubber tread for renewing the tread of a used tire - Google Patents

Description

The invention relates to a rubber tread for renewing the tread of a used tire, its dimensions in relation to the dimensions of the casing prepared for renewal as follows are dimensioned so that the area close to the tread of the rubber tread applied to the carcass is in Tire circumferential direction is under compressive stress.

Such rubber treads are used in the retreading of a worn tire, in particular for soling that extends over the tread extends.

According to the prior art, it is already known from DE-AS 10 67 584, an annular To use treads of greater circumferential length than the tire carcass in a device with a ring shape applied to the surface of the carcass and adhesively bonded to it is that the tread is compressed as a whole in the tire circumferential direction and is under compressive stress. By pretensioning the wear surface of the tread in the tire circumferential direction, the Significantly increased wear resistance.

The disadvantage of this known method, however, is that it requires a not inconsiderable outlay in terms of device technology in order to achieve a faultless one and to achieve even pressure between the carcass and the tread. Especially with large ones Pneumatic tires, for example for tractors or agricultural vehicles, the devices required are large and because of the required precision correspondingly expensive. Nevertheless, in practice it cannot be ruled out that when the tread is compressed when it is applied to the Carcass wrinkles between the carcass and the tread.

It is also from DE-AS 12 98 702 and from

DE-OS 17 79 211 known, the rubber tread for Renewing tires into individual pieces, namely into individual ring-shaped pieces that run parallel to the Tire circumferential direction are applied transversely next to each other on the outer surface of the carcass.

The object on which the invention is based beoteht is to create a rubber tread of the type mentioned, which without wrinkling on easy way under compressive stress on the carcass

ίο can be applied.

According to the invention, this object is achieved in that the rubber tread consists of several There are individual pieces, the inner concave surface in the tire circumferential direction with one opposite the associated curvature of the carcass smaller radius is curved.

Just as the division of the rubber tread into several individual pieces is described in DE-OS 17 79 211, is from DE-OS 19 34 767 a Rubber tread known whose inner concave surface in the area of the tire shoulders, so outside the tire sole, a lower curvature than the associated curvature of the carcass Has radius, but here is quite the opposite of Invention of the smaller radius arranged transversely to the circumferential direction of the tire, so that in the shoulders of the tread when it is applied, compressive stresses arise that are exclusively transverse to the circumferential direction and only in the shoulder area outside the sole surface Generate transverse compressive stresses. The point of this Arrangement in the known tread consists in the trailing edges of the rubber tread to be applied to the carcass with a bias in the shoulder area so that the

> 5 edges if the adhesive strength decreases during the Vulcanization cannot occur.

In the sense of the underlying principles of the invention Task, which is based on the fact that the wear of the new tread to be applied by pressure chip

■ tones should be reduced in the circumferential direction, depending; So the arrangement known from DE-OS 19 34 767 is downright damaging, since this involves the compressive stresses be built across the circumferential direction of the tire and thereby in no way reduce the

Signs of wear and tear, but a reinforcement of the Wear of the rubber tread is caused. The basic idea of the invention therefore does not exist

simply in dividing the tread into several individual pieces to split up and it would by no means be sufficient

so only the inner radius of the tread in to make any orientation smaller than the outer radius of the carcass. According to the invention is rather, it is provided that each of the individual pieces of the rubber tread have an inner concave surface which has a smaller radius straight along the tire circumferential direction than the outer surface of the carcass in the same direction. Only by the combination of these special features provided according to the invention is that set out at the beginning Task, namely, while maintaining the wear-reducing compressive stress along the tire circumferential direction, a wrinkling of the tread without to avoid expensive devices when applying to the carcass, solved.

μ Particularly preferred embodiments and developments of the rubber tread according to the invention are characterized in the subclaims. The invention is illustrated below with reference to

A. Λ

Embodiments explained in more detail with reference to the drawing; it shows

F i g. 1 shows a partial cross-section of a tire carcass used for a tire for agricultural vehicles suitable is;

F i g. FIG. 2 shows a cross section through a stud which is applied to the carcass shown in FIG can; and

Fig.3 is a side view of a tire whose Tread is applied in segments, so individual sections

1 shows a section of a tire carcass 10 which is suitable for an agricultural utility vehicle. The radius of curvature of the outer surface of this portion of the carcass is r. F i g. 2 shows a single piece 12 of a rubber tread, designed as a cleat, which is to be applied to this section of the tire carcass 10. The cleat consists of a vulcanized rubber strip with a radius of curvature r ', where r ■ is smaller than r . A reinforcing strip 14 (e.g. a wire mesh) is provided in the rubber near the verso-tex surface 11 of the cleat of the opposite other surface 13, so that the cleat is not stretchable at this point

When the lug is applied to the tire carcass 10, its radius of curvature is increased, so that its wear surface 11 in the circumferential direction is compressed and after application along the circumferential direction under compressive stress remain

ίο The Fig.3 shows a tire carcass 5, whose The running surface is to be renewed in sections. A number of strips, for example four, are used for Applying to the crown of the carcass prepared in such a way that they together form a complete Form a running surface which can have a smooth, even wear surface 11 for certain purposes. Each Individual piece 23 (FIG. 3) is formed with a radius of curvature which is smaller than that of the tire carcass 5, so that the strip-shaped individual piece 24 has a wear surface compressed along the circumferential direction 11 has.

1 sheet of drawings

Claims (4)

1 claims: 1. Rubber tread for renewing the tread of a used tire whose dimensions in relation to the dimensions of the used tire Renewal prepared carcass are dimensioned so that the area close to the tread of the The rubber tread applied to the carcass is under compressive stress in the circumferential direction of the tire, characterized in that the rubber tread consists of several individual pieces (12, 23, 24) consists, the inner concave surface (13) in the circumferential direction of the tire with one opposite the associated curvature of the carcass (5, 10) smaller radius ^ is curved 2. Rubber tread according to claim 1, characterized in that the individual pieces (12, 23, 24) on or near the concave roof (13) have a non-stretchable reinforcement strip (14). 3. rubber tread according to claims 1 or 2, characterized in that the larger Dimensions of the individual pieces (12,23,24) parallel to the Carcass circumference (5.10). 4. rubber tread according to claims 1 or 2, characterized in that the larger Dimension of the individual pieces (12, 23, 24) is transverse to the circumference of the carcass (S, 10).