Patent GB-1403368-A (GB)
Title: Tyre building apparatus
IPC: B29D30/36
Filed: 1972-07-10
Abstract: 1403368 Making pneumatic tyres UNIROYAL 10 July 1972 [13 July 1971] 32191/72 Heading B7C  A method of making a pneumatic tyre includes the steps of applying one or more plies about the periphery of a cylindrical drum B to form a carcass 98; positioning bead wires 99 having apex strips 99a to lie radially outwardly of the carcass and slightly axially outwardly of the centres of annular grooves 78a, 78b on the drum periphery-Fig. 3a; radially expanding the drum B so that the bead wires enter the grooves 78a, 78b and become embedded in the carcass, the embedding causing marginal edges 98a of the carcass to be turned partially around the bead wires; advancing shaping rings axially inwardly from both ends of the drum to turn the edges 98a further about the bead wires and bring them into contact with the apex strips- Fig. 3c; and radially expanding the carcass portion between the bead wires, while axially contracting the drum B and axially inwardly moving the shaping rings to maintain the edges 98a in contact with the apex strips, in order to shape the carcass to toroidal form and join the carcass portion between the bead wires with the marginal edges 98a and apex strips 99a-Fig. 3a. In the illustrated method respective shaping ring assemblies 91, 92, 93 and 911, 92<SP>1</SP>, 93<SP>1</SP> adjacent the drum ends co-operate in turning the marginal edges 98a about the bead wires and also assist in shaping the carcass to toroidal form. A device 100 as described in Specification 1,402,431 may be used to initially position the bead wires. A breaker 101 and tread 102 assembly may be incorporated in the tyre by positioning a transfer ring 103 holding the assembly around the carcass prior to its expansion to toroidal form, Fig. 3c, such that on expansion the carcass comes into contact with the assembly which is thereafter stitched- Fig. 3e. Sidewalls 106 may be fitted to the expanded carcass by placing them on bladders 41 41<SP>1</SP> on the rings 91, 91<SP>1</SP>, moving the rings 92, 92<SP>1</SP>, 93, 93<SP>1</SP> away from the expanded carcass and then inflating the bladders and advancing the rings 92, 92<SP>1</SP>, 93, 93<SP>1</SP> axially inwardly to force the bladders to apply the sidewalls 106 to the carcass (Fig. 3f not shown). The drum B Fig. 2b comprises end sections B 1 , B 2  each having radially movable peripheral segments, e.g. 77a, supported on plates, e.g. 70a, 71a, rotatably mounted on a sleeve, e.g. 74a, slidably mounted on a main shaft 1 of the tyre making apparatus, each sleeve having two oppositely screw-threaded portions 74e, 74f mounting nuts, e.g. 75a 75b, which are connected through pivoted links, e.g. 79a, 77c, to the peripheral segments. The end section B 1  is fastened to axially extending rods 12a and the section B 2  to rods 12b. Arms 79 pivotally connected at 79c connect the sections B 1 , B 2  and form the centre section B 3  of the drum, a membrane 78 being provided around the drum having an aperture 90c to admit pneumatic pressure between the drum surface and a carcass to expand the carcass to toroidal form. A drive unit A, Figs. 2b, 2c, rotatably supports the main shaft 1 through bearings 2a, 2b in a hollow casing 3 around the shaft, the casing itself being rotatably mounted by bearings 4a, 4b to a frame E. Pneumatic clutches 8a, 8b, connected to the frame E and to a drive pulley 6 on the shaft 1 respectively, are provided, both of which are engageable with a drum 9 on the casing 3. Actuation of the clutch 8b alone enables rotation together of the shaft 1 and casing 3 to rotate the building drum B as a whole, and actuation of clutch 8a alone causes only the shaft 1 to rotate thereby resulting in the nuts 75a, 75b, in each drum end section moving towards or away from one another thus radially expanding or contracting the drum. The drive unit A provides for axial expansion and contraction of the drum by means of screws 19a with oppositely screwthreaded portions which can be rotated to cause a plate 22a, to which the rods 12a are connected, to move towards or away from a plate 22b to which the rods 12b are connected. Means are provided in the drive unit for monitoring and controlling radial and axial expansion and contraction of the drum. Each shaping ring assembly comprises a carrier 135 on which the rings 91-93 or 91<SP>1</SP>-93<SP>1</SP> are mounted, the carrier being slidable along a support tube 34 in the axial direction of the drum by means of jacks (not shown). The rings 91, 92 are rotatable relative to the carrier 135, and all the rings may be moved axially with respect to the carrier by jacks (not shown) to enable them to shape blocks of different profiles. The inflation of members 42a, 42b secured to the carrier 135 prevents rotation of the ring 91 and creates a sealed chamber through which pneumatic pressure can be admitted to ducts leading to the sidewall applying bladder 41. A unit D, Fig. 2a, at the opposite end of the drum B from the unit A includes a member 61 which can be axially extended or retracted by a jack 63, 63a to engage or disengage a hollow portion 1a of the shaft 1 emerging from the end section B 1  of the drum, rotation of the shaft 1 being transmittable to the unit D through the member 61 and portion 1a. The unit is supported on a carriage 49 such that it can be moved away from the shaft 1, along horizontal rails (50a) (50b) (see Fig. 1a, not shown) lying perpendicular to the axis of the shaft 1, to enable a tyre blank to be removed from the apparatus. Means are provided on the carriage and rails to centre the member 61 with respect to the portion 1a. Specifications 1,315,675 and 1,403,367 are also referred to.