Patent GB-1247419-A (GB)
Title: Tire molding apparatus
IPC: B29D30/06
Filed: 1969-05-28
Abstract: 1,247,419. Moulding tyres. GOODYEAR TIRE & RUBBER CO. 28 May, 1969 [1 July, 1968], No. 26878/69. Heading B5A. A tyre moulding press includes a number of tread moulding segments 30, Figs. 1 and 2, spaced about the tyre axis 54 and movable radially to an inner position to provide a tyre moulding cavity, and to an outer position to enable a tyre to be moved coaxially into and out of the expanded cavity 60. The tyre T is located about a bladder 230 secured to a bladder assembly 226 secured to a tube 202. To load the press, the segments are moved radially outwardly and the tube 202 moved axially to the left by a piston and cylinder 296 to bring the bladder assembly clear of the cavity 60. After locating a tyre for treatment on the assembly, the tube is retracted and the segments 30 moved inwardly and the bladder supplied with heated fluid via a supply line 280. The open ends 62, 64 of the cavity 60 before tyre vulcanization, are closed by tyre bead engaging rings 66, 68, the ring 66 comprising a number of segments 70 which move radially with the segments 30 and which are moved axially to close the cavity end 62. When the segments 70 are moved radially inwards a ring 360 is engaged within a groove 362 of the segments 70; the ring 360 is carried by an axially slidable ring 356 connected by a linkage 344 to one end of a shaft 318 axially movable by a piston-and-cylinder motor 325 whereby shaft movement effects axial movement of the segments 70. Each segment 30 has a series of interconnected bores 32 for heating fluid, and lugs 120, 126 extending along its length which, when the press is closed, abut similar lugs on adjacent segments. A channel 130 between abutting lugs receives a key 128, and each pair of such lugs is clamped by a vertically adjustable clamping mechanism 140 supported by the piston-rod of a fixed piston and cylinder motor 150. Each clamping mechanism includes a pair of jaws 142 pivoted on a pin 146 slidable in guide channels, and the jaws are opened and closed by a toggle linkage 164, 165 operated by a piston and cylinder motor 172. Each segment is driven radially by a piston and cylinder motor 101, and is guided by pairs of rack members 75, 85 located on the insides of fixed plates 24, 26 of the press, which are engaged on one side by a roller 92 and on the other by a pinion 90, each pair of members 90, 92 being carried by a lug 84 on the segment. In the embodiment of Fig. 5 the radially movable tread moulding segments are grooved at 454, 456 to receive the annular flanges 458, 460 of tyre bead engaging rings 462, 464 when the press is closed. The ring 464 and a ring 550 clamp a bead of a bladder 472 and are mounted on a sleeve 546 extending forwardly of a ram 500 movable axially by a piston and cylinder motor 656. The other bladder bead clamping assembly 568, 570 and the tyre bead engaging ring are supported on a tube 534 telescopically mounted within the sleeve 546 and movable axially relative thereto by a piston and cylinder motor 630. The ring 462 is removably mounted on a ring 580 by a tongue and groove connection, and is removed when a tyre is loaded on to the bladder after the motor 656 has driven the bladder assembly axially away from the mould cavity and the inner tube 534 has been axially extended by the motor 630. Adjustment of the axial spacing between the two bladder bead clamping assemblies is provided by an adjustable screw 590 which carries a nut 602 with abutments 604 which, in a limiting position abut a part 522. The rear of the screw is rotatably received within the end of the tube 534, and by rotating the screw at 592 the nut position may be adjusted. In the embodiment of Fig. 8 for treating large tyres, the press is located in a pit 712 and has tread moulding segments 750 radially movable by hydraulic cylinders 764 and mounted on wheeled carriages 756 engaging tracks 760. Adjacent segments are interconnected by radially movable clamping devices 800 supported by dollies 787. A lower bead engaging ring 820 has a tongue and groove connection with the segments, and the lower bead of the bladder 834 is clamped to it by a member 836. The upper bladder bead assembly is clamped to the upper end of a ram 724. An outer tyre bead engaging plate 860 is removably secured to the upper assembly by hold-down devices 864, and also has a tongue and groove connection with the mould segments. After moulding a tyre, pressure within the bladder is released, the clamping devices 800 and segments 750 retracted, the devices 864 released, the plate 860 removed by a crane, and the ram extended to bring the bladder to its cylindrical form, and the tyre removed.