Patent GB-1337031-A (GB)
Title: Tyre building machine
IPC: B29D30/32
Filed: 1971-11-17
Abstract: 1337031 Tyre building machine GOODYEAR TIRE & RUBBER CO 17 Nov 1971 [18 Dec 1970] 53345/71 Heading B7C A tyre building machine comprises a cylindrical building drum 10, means at each end of the drum for radially moving the end portions of the drum from a first diameter to a second larger diameter, tyre bead core gripping means including a plurality of radially movable rigid members located adjacent each end of the drum, and means radially moving each gripping means between a first diameter not substantially greater than the first diameter of the end portions and a second diameter less than the second diameter of the end portions, in use, the means for moving the end portions to their second diameter being operable only after the bead gripping means have been moved to their second diameter. Each end portion of the drum 10 may comprise a plurality of part cylindrical segments 48 carried on rods 46 slidable in bores 45 in an annular housing 44 attached to a hub 31 on a shaft 11 of the machine, and each bead gripping means may comprise a plurality of fingers 59 slidable in slots 58 in a ring 57 secured to the adjacent housing 44, in use, admission of pressurized fluid to a chamber 34 in the associated hub 31 moving a piston 35 axially inwardly thus causing a cam 36, connected to the piston and acting on rollers 47 on the rods 46 and rollers 71 on rods 78 engaged with the fingers 59, to move firstly the bead gripping means and subsequently the end portion of the drum from their first diameter positions shown in Fig. 1 to their second diameter positions which respectively are defined by the rollers 71 resting on a surface 37 of the cam and the rollers 47 resting on a surface 39 of the cam. The bead gripping means and end portions of the drum are movable axially by means of screw-threaded portions on a shaft 13 driving nuts 21 associated with the hubs 31. Extending between the end portions of the drum are part-cylindrical segments 84 overlapping the segments 48 and radially movable by means of pistons 88 in a member 87 on the shaft 11, the segments 48 and 84 being covered by an inflatable rubber sleeve 55. An auxiliary drum 79 carrying an inflatable ply turn up bladder 80 is provided adjacent each end of the drum 10. In use of the machine, at least one carcass ply 95 is laid with its ends on the bladders 80 and bead cores 96 are located axially inwardly of the ply ends at a distance no greater than the thickness t of the ply or plies, the bead gripping means are moved to their second diameter to press the carcass material against the bead cores, Fig. 6c, the end portions of the drum are moved to their second diameter and the segments 84 are moved radially outwardly, the end portions and bead gripping means are moved axially inwardly to form shoulders 97 in the carcass, Fig. 6E, the bladders 80 are inflated to turn the ply ends up around the bead cores and are then deflated, the carcass is shaped to toroidal form by inflating the sleeve 55 and moving the end portions and bead gripping means further axially inwardly, a tread 98 is applied using a ring 99, Fig. 6H, and finally sidewall rubbers 100 are applied using the bladders 80 and pusher rings therefor (not shown).