Patent GB-977178-A (GB)
Title: Tyre building apparatus
IPC: B29D30/24
Filed: 1963-03-20
Abstract: 977,178. Tyre building apparatus. AKRON STANDARD MOLD CO. March 20, 1963 [July 30, 1962], No. 11143/63. Heading B7C. Tyre-building apparatus (Fig. 1), comprises a rotatable, collapsible building drum 1 adapted to carry fabric plies and a bead core, expansible ply turning means coaxial with the drum at least at one end, and rotatable means for progressively deforming the expansible means to facilitate ply turning about the bead core. The apparatus also includes movable beadsetter units 4, 6, a stitcher unit 19, driving means incorporating a braking unit 117 (Fig. 5, not shown) and a control system (Figs. 18 . . . 20, not shown). Building drum.-Fig. 3 shows the drum 1, comprising a plurality of segment supporting members 36, each radially movable on a guide stub 59 projecting from a hollow shaft 2, and each carrying axially adjustable wing members 37, 38 separated by interchangeable spacers 56, on which plies F are laid. The drum is expanded radially by axially moving a rod 27 (by a fluid motor 28, Fig. 1) which carries cams 22, 23 whose surfaces 24, 25 react on surfaces 41, 42 of members 36. Shaft 2 also carries expansible diaphragm units 10, 12, supporting diaphragms 78, 79 which are inflated through conduits 86, 87 from a space 82 into which fluid is introduced. Motor 104 (Fig. 1), drives the drum through a belt 115, the motor being mounted pivotally (Fig. 4, not shown), to adjust the tension. The shaft 2 carries a pulley over which a brake band may be tightened to stop the drum. Diaphragm displacement assembly.-The inflated diaphragms 78, 79 are displaced (Fig. 15) to facilitate ply turn-over by two wheels 17, 18 rotatable on a shaft 132 (Fig. 7), this assembly being behind the drum 1 as seen in Fig. 1 (Fig. 2, not shown). The axial positions of wheels 17, 18 are variable, set screws 137 fixing them in place on the shaft. Fig. 6 shows how the wheels are tilted into contact with the diaphragms by a cylinder 151. Stitcher assembly.-Stitcher wheels 20, 21, are rotatably mounted, carried on carriages 160, 161 (Fig. 1), below the drum 1, and are movable vertically into contact with plies thereon by cylinders 158, 159 in the carriages (Fig. 6). Carriages 158, 159 move axially on two oppositely threaded parts of a drive screw 171 driven by a motor 180 (Fig. 1). Bead setter assembly.-Fig. 9 shows bead holders 198, 199, axially movable from positions straddling diaphragms 78, 79 (Fig. 1), to withdrawn positions (shown dotted). Holder 198 is pivotable about a horizontal axis for tilting back when withdrawn, cam follower 210 following cam track 209. Axial movement is by a cylinder 215 which displaces piston 216 and hence carriage 211 (Fig. 9). Carriage 211 carries a rack 219 which then rotates a pinion 221 and moves a rack 220, to which carriage 200 is attached, in the opposite direction. Control.-Figs. 18 . . . 20 (not shown), illustrate the control circuit, certain stages in tyre assembly being initiated by push-buttons, and the various steps such as diaphragm inflation, diaphragm deformation by wheels 17, 18, bead holders in position, stitcher movement are time-controlled. Operation.-Plies F are applied to the drum which may then be expanded, the bead cores positioned, diaphragms 78, 79 inflated (Fig. 14) to begin ply turnover, wheels 17, 18 engaged with the diaphragms (Fig. 15) to complete turnover, wheels are withdrawn and diaphragms deflated. Stitcher wheels 20, 21 are applied to the turned-over ply near the bead cores and then after one turn of the drum, are moved axially inwards. The tread is applied with the stitcher wheels "centred" (Fig. 1), and they are then moved outwards again to stitch the tread to the carcass, and then inwards again and finally withdrawn from contact with the plies. The drum is collapsed and the tyre removed.