GB1231597A - - Google Patents

Abstract

1,231,597. Moulding tyres. K. ZANGL. 30 Sept., 1968 [10 Oct., 1967; 11 Sept., 1968], No. 46348/68. Heading B5A. A pneumatic tyre is placed in a vulcanizing press, comprising opposed mould halves which when closed abut along a plane perpendicular to the mould cavity axis, by locating the tyre between the open mould halves, pulling the tyre beads apart to decrease the tyre diameter and then forcing the beads together to decrease the tyre diameter for facilitating mould closure. The press includes mould halves 2a, 2b with adjacent bead engaging rings 4a, 4b at the peripheries of plates 4, 4<SP>1</SP> which may move relative their respective mould halves such that the sum of such relative movements is at least equal to the distance between the inner edges 2a<SP>1</SP>, 2b<SP>1</SP> of the closed mould cavity, Fig. 4. The bead ring 4b is urged upwardly relative its mould half by springs 6b, and the bead ring 4a is connected by a bayonet joint to the lower end of a cylinder 9 urged downwardly relative the upper mould half by springs 6a. After placing the t yre on the lower bead ring the lower mould half and its associated heating ring 3b is raised until both bead rings are forced into the tyre beads. Steam under pressure is admitted to the tyre interior through a duct 5 and the tyre beads are thereby urged apart against the pressure of the springs 6a, 6b to decrease the external diameter of the tyre, Fig. 3; the steam is released and the mould halves brought together, and simultaneously the bead rings are forced together, Fig. 4. The tyre is then repressurized and vulcanization effected, Fig. 5 (not shown). Condensate or hot water, if the latter is used for vulcanization, may be removed from the tyre by opening the press and forcing the bead rings apart so that water may flow from the duct 5. Additional condensate drawoff conduits may be located between the plates 4, 4<SP>1</SP> and connected to the duct 5 whereby pressure medium supplied through duct 10 forces condensate from the tyre interior. In the modification of Fig. 9, the upper bead ring 4a is connected by a bayonet joint to the lower end of a cylinder 900 driven vertically by a fluid motor 905, whereby the tyre bead rings are brought together to decrease the tyre diameter before the press is closed. Each bead ring may have a stepped sealing surface which engages the tyre bead, and a sealing ring may be located in a groove in the sealing surface.