| 摘要 |
1390024 Pneumatic tyre and wheel assemblies DUNLOP HOLDINGS Ltd 7 March 1972 [16 March 1971] 7024/71 Heading B7C A wheel and tyre assembly comprises a wheel rim 1 having a pair of spaced tyre bead seats 2, 3 and annular substantially axiallyoutwardly-extending flanges 4, 5 located one adjacent each bead seat to support the sidewalls of a deflated tyre, a tyre 6 mounted on the rim 1 to define an inflation chamber therewith, and means to prevent the tyre from being dislodged from the rim when running deflated, the tyre 6 having in each lower sidewall region an annular rubber buttress 9 or 10 with a substantially axially-outwardly-extending radially inner face, and each buttress being located such that when the tyre is inflated to its normal working pressure the buttress rides clear of the rim 1 but should the tyre deflate the buttress contacts the adjacent flange 4 or 5 to support the associated tyre sidewall and accomodate relative movement between the rim and the sidewall. Each buttress may have a series of radially directed and axially extending castellations on its radially inner face (Fig. 2, not shown). The tyre may be a radial-ply tyre with a breaker assembly or alternatively a cross-ply tyre with or without a belt. The aspect ratio of the tyre may be 30-75% and the tyre tread width may be greater than the distance between the bead heels of the inflated tyre. The sidewall supporting surfaces of the flanges 4, 5 may be coated with a low friction material. The means for preventing the deflated tyre from being dislodged from the rim may, as shown, comprise a non-decreasing rim diameter between the bead seats 2, 3 so that the rim is without a well, and/or movable studs or projections on the rim for preventing at least the outboard tyre bead from moving. The assembly may be provided with a saddle projecting radially outwardly from the rim to support the interior surface of the tread portion of the deflated tyre, which saddle may also act as a bead spacer. Where the rim is without a well it may be a split rim or a rim whose well has been closed up by axial compression after mounting of the tyre. The tyre may be secured to the rim by swaging the rim over the tyre beads after mounting of the tyre. The assembly may be provided with a lubricant for the tyre interior surfaces, as described in Specifications 1,359,467 and 1,359,468, to facilitate running of the assembly with the tyre deflated. Specification 1,359,463 is also referred to. |
