| 摘要 |
716,364. Pneumatic tyres. GENERAL TIRE & RUBBER CO. July 24, 1950 [Aug. 26, 1949], No. 18443/50. Class 144(1) A method of building a pneumatic tyre by the flat-band process comprises a primary step in which the mid-portion of the (flat) casing is expandedsimultaneously, throughout its circumference-to a diameter greater than that of the bead assemblies, applying the latter to the (unexpanded) edge portions of the casing, folding these portions about the beads, and then further expanding the casing. As shown, the flat casing P is laid on a building-drum D comprising segments 16 fitted with cover-plates 22 the drum being expanded from the position shown in Fig. 3 to that shown in Figs. 5 and 7 by means of wedge-rings 27 co-operating with radial pins 14 carried by the drum-segments 16. Relative displacement of the rings 27 is effected by means of a shaft 36 having oppositely-threaded portions 33, 34 carrying nuts 32 mounted for traverse in a casing 8 surrounding the shaft 36. The wedge-rings 27 are fitted with gibs 28 engaging'radial sockets 31 in the nuts and guided, against rotation, in slots 30 in the sleeve 8. On return movement of the rings 27, the drum is automatically contracted by the reaction of springs 17 connecting the drum-segments to the flange 11 of a sleeve 10 on which the wedge-rings 27 are slidably mounted. The bead-assemblies A may be positioned against the shoulder-portions of the partially-shaped casing by hand. or by means of setting-devices such as those described in Specifications 608,597 and 614,162. |
