Bead wire coupling system - with sleeve compressed into engagement with transverse grooves of increasing depth in the wire

摘要

In an endless ring as an insert for the part of a pneumatic tyre, with a high strength steel wire the two ends of which each have a series of transverse grooves spaced one behind the other, and are joined together by a breas sleeve engaging the transverse grooves and having an outer diameter less than twice the wire diameter, generally as disclosed in the parent application, the improvement whereby the depth of the transverse grooves progressively increases in the direction of the ends of the wire while advantageously the width of the grooves increases in correspondence therewith. The ultimate strength of the bead ring in the zone of the coupling sleeve is increased particularly with respect to bending stresses. A sleeve material of 65 kp/mm2 can be used without risk of falling below the prescribed minimum breaking load for the joint.