GB1514474A - Tyre and wheel assemblies - Google Patents

Abstract

1514474 Tyre and wheel assemblies DUNLOP LTD 13 Aug 1975 [23 Aug 1974] 37159/74 Heading B7C In a tyre and wheel assembly, Fig. 9, the tyre tread portion 1 is wider than the remainder of the tyre and is reinforced over substantially the whole of its width by a substantially inextensible reinforcing belt 2, and, as considered in cross-section, the sidewalls 3, 4 of the tyre are each in lengthwise compression and each extend radially and axially outwardly between the wheel rim and tread portion such that the longitudinal centreline of the sidewall is straight over substantially the whole of its length. The sidewall compression occurs as a result of mounting the tyre on the wheel rim, and may be created by axially displacing the inner edges of the sidewalls from positions D 1 , D 2 to positions C 1 , C 2 , Fig. 1, on mounting the tyre, which causes shortening of the sidewalls as shown and hence compression since the tread portion cannot expand to accommodate the sidewall displacements. When the tyre is mounted on the wheel shown in Fig. 9 the sidewalls 3, 4 are axially displaced by turning screws 13 to force apart plates 8, 9 on which the sidewalls are seated, and then the plates are secured in position by bolts 11 and spacers 12 to hold the sidewalls under compression. The tyre may be non-inflated or inflationary air may be used provided that its pressure is not such as to cause decompression of the sidewalls. Each sidewall may have a portion of reduced thickness adjacent its inner periphery and/or adjacent its outer periphery and may be thickened at its junction with the tread portion as shown in Fig. 7. The surfaces of each sidewall may be curved in cross-section as shown in Fig. 7. Each sidewall may consist wholly of a rubber harder than that of the tread portion and the bead portion of each sidewall may be without a reinforcing core. The longitudinal centreline of each sidewall may be at an angle of 25-70 degrees to the rotational axis of the assembly. The belt 2 may comprise two steel cord plies having equal and opposite cord angles of 10-80 degrees with respect to the circumferential, or alternatively three cord plies of which one ply has a cord angle of 90 degrees and the others equal and opposite angles of 10-45 degrees. Extra reinforcement may be provided at the edges of the belt 2, either by folding the belt ply edges or by providing at the belt edges further strips of cord fabric with angled cords or windings of circumferential cord. In one embodiment, Fig. 4a the tyre is provided internally with an additional pair of sidewalls.