GB768478A - Improvements relating to pneumatic vehicle wheel tyres - Google Patents

Abstract

768,478. Pneumatic tyres. PIRELLI SOC. PER AZIONI. March 22, 1955 [March 27, 1954], No. 8316/55. Class 144 (2). A pneumatic tyre in which the bead comprises one or more bead cores 1 of wire around which the ply or plies of the tyre carcass are wrapped has included in the bead structure a reinforcement 5 consisting of at least one layer of fabric disposed in the structure to lie against the bead core or cores 1 laterally thereof to stiffen the structure against deflection of the body of the bead relative to and around the core or cores 1 the layer merely flanking and not being wrapped around the bead core or cores. In the arrangement shown in Fig. 3 the reinforcing strip 5 is placed between the bead cores 1 and the whole assembly is surrounded by a flipper strip 4. In a further arrangement shown in Fig. 4 three reinforcing strips 5, 6 are placed between two bead cores 1. In a further modification, shown in Fig. 5, the reinforcement 5 consists of a single strip of fabric folded around an auxiliary core A and placed against the side of a single bead core 1 or between two bead cores, Fig. 6 (not shown). The reinforcement may be of the " cord " type with the direction of lay of the cords the same or different in the various layers. When the same the direction of lay at any given point along the reinforcement, circumferentially of the tyre, is parallel to a plane radial to the tyre, containing the rotational axis thereof and passing through said point and when different the several directions are symmetrically arranged with respect to said plane. The bead cores 1 are rectangular, the width L, Fig. 4, being one third to a half of the height H. When two or more reinforcing layers 5, 6 are used the lower edges are level with the bottom of the bead core or cores and the upper edges may be level or of different heights.