GB1484477A - Apparatus for making pneumatic tyres - Google Patents

Abstract

1484477 Tyre building machine GENERAL TIRE & RUBBER CO 19 Aug 1974 [17 Sept 1973] 36478/74 Heading B7C A tyre building machine comprising a radially expansible drum 10 and a transfer ring 53 for transporting a tread and belt assembly 52 is provided with two annular guide members 58, 59 for guiding a carcass 57, built up on the drum 10, during its expansion into engagement with the tread and belt assembly, each guide member comprising flexible helical springs 63 mounted on supports 64, with the helix axes of the springs extending circumferentially of the guide member so that the springs can rotate during carcass expansion. As illustrated, the annular guide members are each mounted on a bead ring carrier 21, 22 and the machine includes end drum assemblies 12, 13 incorporating carcass turn-up bags (not shown). In an alternative arrangement the members are carried by the transfer ring. A tyre is manufactured, using the illustrated machine, by applying parallel cord carcass plies (e.g. radial plies) to the drum 10, inflating bags 20 to expand the drum 10 to form shoulders, moving the carriers to apply bead rings to the shoulders, moving the carriers away from the drum 10, inflating the carcass turn-up bags, moving the carriers inwardly, and deflating the bags, to assist in the carcass turn-up, moving the carriers axially outwardly, stitching the turn-ups, applying other components, e.g. sidewall rubbers and chafer strips, pivoting the carrier 22 to a horizontal position by means of cylinder 38 to permit transfer ring 53 to be moved to the position of Fig. 2, restoring carriers 21, 22 to the position of Fig. 2, inflating the annular bag 19 to bring the beads 72, 73 axially inwardly of elements 77, inflating bags 20 and subsequently axially contracting the drum 10. Stitching of the tread and belt assembly is effected after axial removal of the transfer ring. The tyre is then removed after collapse of drum 10 and removal of carrier 22 to its horizontal position. The specification also discloses a method of manufacturing a tyre, using the same machine, in which the beads remain axially outwardly of the elements 77 (Figs. 6-8, not shown).