| 摘要 |
775,058. Tubeless tyres. GOODRICH CO., B. F. July 21, 1955 [Aug. 2, 1954], No. 21118/55. Class 144 (2). To provide for an air-tight seal with a circumferentially split rim, a tubeless tyre 10 has at least one of its beads provided on its radially inner surface with an air-retaining ring 20 comprising an annular radial-load supporting portion 21, and a flexible portion 22 in sealing engagement with the bead and having a flexible lip 26 spaced radially inwardly from the bead and extending axially towards the bead toe to define an axially inwardly opening recess 27 whereby in use on a rim 30 the lip 26 is caused to seal against the rim base by the pressure of inflation air. As shown in Figs. 1 and 3, the tyre bead is formed with twin cores 11, 13 of different diameters to provide a recessed heel portion to accommodate the ring 20 which may be cemented or bonded in the recess, the flexible portion 22 having a radially outer lip 24 to overlap the edge of the tyre liner 17. The portions 21, 22 of the ring 20 may be formed of rubbers of different hardness, or alternatively, the portion 21 be reinforced by a wire or fabric core, or as shown in Fig. 6, by a metal sheath 56. Sealing ribs 28 may be provided on the lip 26 which is moulded to diverge from the lip 24. The tyre may be used on a rim, Fig. 3, having a detachable endless flange 36 retained by a split-ring 37 which has a bead seating portion 41 on which rests the load-bearing portion 21 of the ring 20. In use the radial load is borne by the bead toe 18 and the ring portion 21. Alternatively the wheel rim may comprise a split detachable flange engaged directly in the rim base gutter 33. Fig. 5 shows an alternative arrangement wherein the tyre bead has twin cores 11, 13 of the same, but larger than normal, diameter, and the air-retaining ring 20a secured thereto is formed with its flexible portion 22a sandwiched between toe and heel load-bearing portions 50 and 21. |
