| 摘要 |
<p>1,251,928. Making tyre beads; welding by pressure. BEKAERT S.A. N.V. 26 May, 1970, No. 25252/70. Headings B3A and B3R. A method of making a beadwire for a pneumatic tyre comprises butt welding the ends of a metal wire cable 1 made up of wires 3 twisted together with or without a central core wire or wires 2, heat treating the welded joint to relieve stresses and removing the weld burr by mechanical working. The cable is made of steel wire having a carbon content of from 0À60 to 0À85% by weight and has a rubber coating 4. Clamps 6 of the welding apparatus press the bared ends of the cable together at a pressure of between 0À1 to 0À4 kg./sq. mm. and an electric current is passed through the junction 7 and welds the ends together at a temperature about 1200‹ C. The heat treatment consists of heating the weld region to 850‹ C. followed by cooling. After removing the weld burr the connected ends of the cable are recoated with rubber. The bead wire is embedded in the moulded tyre and is surrounded by cord plies (Figs. 3 and 4, not shown).</p> |
