Build-up drum for tyre prodn. - has pressure ring acting on spreader ring which has keyhole type slots from alternate sides and outer rubber ring of specified hardness

摘要

A build-up drum for tyre prodn. and its intermediates has an adjustable dia. spreader ring for holding the tyre members (and the bead in partic.) centrally. An axially moving ring with taper on one side is mounted on the centre line; this ring can be pressed by conventional means into a correspondingly tapered spreader ring against a spring pressure; this spreader ring is made of a resilient material and has slots alternating from its i.d. and o.d. These slots all end in axial holes whose dia. is approx. one third to half the width of the segments formed in the ring; these holes reach 1.5-4.0 mm from the relevant end i.d. or o.d. of the ring; the spreader ring has an outer cover ring of rubber 20-30 mm thick of Shore hardness 65-75. ADVANTAGE - The simple construction of drum produces high-grade tyres and intermediates. In particular it provides uniform results.