UN APARATO PARA FABRICAR NEUMáTICOS

摘要

907,693. Building pneumatic tyres. DUNLOP RUBBER CO. Ltd. Dec. 31, 1958 [Jan. 15, 1958], No. 1370/58. Class 144 (1). A tyre-building apparatus comprises a cylindrical, inflatable, radially expansible diaphragm 5 of a length sufficient to support the full width of the tyre carcase plies and supported at its ends by supporting discs 3, 4 which are movable axially towards or away from each other, there being a pair of radially expansible bead locating members 10, 11 mounted coaxially within the diaphragm for relative axial movement so that, when the tyre plies are wrapped around the diaphragm and the bead locating members are expanded to clamp the plies to the bead cores, the diaphragm is inflated and the supporting discs 3, 4 and locating members 10, 11 are respectively approached towards each other to effect turn-over of the ply ends around the bead cores and simultaneous shaping of the tyre carcase to arched section ready for application of a tread band thereto. As shown, the supporting discs 3, 4 and bead locating members 11, 12 are each slidably mounted on a shaft 1 and are respectively moved axially by means of a pair of rotatable, axially fixed tubes 14 which have appropriate right and lefthanded screw engagement with rods 6, 7 operatively connected with the discs 3, 4 and with bushes 17, 18 in the locating members 10, 11. The pitch of the screw engagement of the bushes 17, 18 is half that of the rods 10, 11 so that the discs 3, 4 are moved at twice the rate of the members 10, 11. The bead locating members comprise annular supports 32, 33, each having an outer peripheral recess 35 housing an inflatable rubber tube 19 within a series of segments 37 which are peripherally grooved to locate a bead core on radial expansion occasioned by inflation of the tube 19. The segments 37 are expansible radially against the action of a garter band 38 or alternatively the segments 37 are replaced by a stretchable rubber band. To assist in effecting ply turnover, the end discs 3, 4 carry frusto-conical baffles 36a, 36b which serve to force those inflated end portions of the diaphragm axially outwardly of the bead cores in a direction, on approach movement of the discs, towards the arched centre portion of the carcase and thereby stitch the ply ends around the bead cores. Specification 907,692 is referred to.