Patent GB-985697-A (GB)
Title: Improvements in or relating to tyre building machines
Inventor: TREVASKIS HENRY WILLIAM
IPC: B29D30/32
Filed: 1960-08-16
Abstract: 985,697. Tyre building machines. DUNLOP RUBBER CO. Ltd. Aug. 4, 1961 [Aug. 16, 1960], No. 28273/60. Heading B7C. A tyre building machine comprises a rotatable high-overlap former 2 having an axially movable bead holding and centring member 10 coaxially mounted at each end, each member 10 having a radial bead supporting face 26 and a series of radial pins 15 which are movable radially across the face 26 to centre a bead ring thereon coaxially with the former. The former 2 is mounted cantilever fashion on a shaft 4 which is supported in a frame 3 and is normally driven by a motor 5. A sprocket 70 is mounted on the shaft to drive in one direction and free wheel in the other, the sprocket being engaged by a chain 72 which is attached at one end to a pneumatic piston 73, and at the other end to a return weight (not shown), whereby actuation of the piston effects a single complete revolution of the drum for application of the carcase and tread plies. The bead centring members 10 each comprise a ring 14 which is backed by an annular plate 25 providing the surface 26 and which is radially holed to receive the pins 15. The outer periphery of the ring 14 is recessed to house bowed leaf springs 20 extending one transversely through each pin 15 and serving to bias the pins radially outwardly. A cam ring 17, rotatably mounted in the recess of ring 14, has a separate inner peripheral cam face 19 for each pin 15, the cam ring 17 being manually rotatable by a handle 21 to effect radially inward centring movement of the pins 15. U-shaped magnets 27 are spacedly secured around the ring 14 so that their pole faces are flush with the face 26 and serve to hold a bead ring against said face 26. Each member 10 is carried by a sleeve 34, 37 respectively for movement axially of the former along a shaft 35, the member 10 at the free end of the former being rotatably mounted on its sleeve 37, by a hub 36, so that it may be swung clear of the former for removal of a completed tyre blank. Pairs of guide rollers 39 depending from the hub 36 and sleeves 34, 37 engage a guide rail 38 during axial movement of the members 10 to ensure coaxial relation with the former. Each member 10 carries a bracket 31 which between them mount a tread centring device (not shown) when the members 10 are in the intermediate position shown in Fig. 6. Axial movement of the members 10 is effected by a lever 43 pivoted centrally of its ends on a frame bracket 44 at the mid plane of the former, the ends of the lever 43 being pivotally connected by links 41, 42 respectively to the sleeves 34, 37. Clockwise rotation of the lever 43 by a handle 45 moves the members 10 toward each other until the links 41, 42 abut, in which position the members 10 are at the desired positions of location of the bead rings symmetrically on the former 10. On return movement of the members 10, a pawl 51 on the lever 43 engages an eight-teeth ratchet 48 to rotate it, and a wheel 46 carried thereby, into a position where one of four radial faces 47 on the wheel 46 is in an upstanding position. Subsequent approach movement of the members 10 is then stopped in the intermediate position, Fig. 6, by engagement of a stop 50 on the sleeve 37 with the upstanding face 47. The return of the members from the intermediate positions effects a further one eighth rotation of the wheel 46 to withdraw the face 47 ready for a next full approach movement of the members 10. A tread stitcher 12 is located below the former 2 and comprises a pair of stitcher wheels 56 having opposite screw-thread engagement with a correspondingly screw-threaded rod 57 secured between a pair of swing arms 58. The arms are swingable by a pneumatic motor 65-67 between a position where the wheels 56 engage a constantly rotating return roller 61 and a position where the wheels engage the tread on the former 2. Specification 884,513 is referred to.