Trapezoidally shaped rubber patch to repair broken metallic cords in the sidewalls of tubeless or tube-type radial tyres, and manufacturing process

摘要

The inner patch to be applied to tubeless or tubed radial tyres which have been subjected to the ruptures of three or more metal cords in their side walls constitutes an improvement to the inner patch with a convex-surfaced rubber tenon according to the same inventor's European Patent Application No. 87114126.3. …??Its principal characteristic lies not only in the rubber tenon 2 to be fitted into the window F cut out in the side walls of the tyre, from the region of which the damaged parts of the metal cords are removed, but also in the fact that the rubber layer 1 containing the radial metal cords with which the inner patch is provided is in relief relative to the leading surface A and has the same width and the same trapezoidal length of travel as the base of the rubber tenon 2. …??This makes it possible to place the inner patch in a stable and accurate manner by superposing its metal cords on those of the tyre subjected to ruptures: for this purpose, in the extension of the lengthwise axis of the window F two grooves C are formed, of a width equal to that of the window, that is to say of the rubber tenon, and of a depth equal to that of the rubber which covers the interior of the tyre cords. …??Considerable advantages of the inner patch according to this invention are represented by the possibility of effecting a correct replacement of the damaged metal cords while completely restoring the functional properties of the tyre, and by the impossibility of the inner patch being displaced before the vulcanisation during the retreading stages. …??For references, see Fig. 3. …IMAGE…