Tyre having reduced variations in stresses and weight - comprises carcass and tread reinforced by belt having wrapping of continuous strip of heat shrinking material

摘要

A tyre consists of a carcass (radial, in particular) and a tread reinforced by a belt which has a wrapping of continuous strip of heat-shrinking material. This wrap is cord in particular and is unreeled using a guide with roller, where the guide moves parallel to the axis; the wrappings overlap the belt at a particular angle to the tyre centre line. At the point of reversing the cord strip turns through at least 180 deg. so that there is an interchange in the upper side, a crease point K is produced, and a further covering layer is formed by the reversal of the guide and moving device. Pref. the build-up drum (1) has a belt (2) of two metal cord or aramid cord layers, with an outer polyamide cord strip (c) which shrinks when heated. This (c) forms a wound wrap (3) e.g. 8-15 mm wide (4). ADVANTAGE - The structure eliminates irregularities at the points of reversal and hence improves the tyre by reducing variations in the stresses and weight.