GB741948A - Improvements in or relating to vehicle tyres and the manufacture thereof - Google Patents

Abstract

741,948. Wheel tyres. CONTINENTAL GUMMI-WERKE AKT.-GES. Jan. 19, 1953, No. 1530/53. Classes 144 (1) and 144 (2). [Also in Group V] A solid rubber band-tyre has a base 3 of hard rubber in which are embedded bundles 4 of smooth-wire windings. The bundles may be of rectangular section and are transversely spaced. The tyre is frictionally retained either on a plain rim or a rim 1 having a circumferential groove to receive a locating rib 7 on the tyre base. Alternatively the tyre base may have an inner periphery which slopes radially inwardly from each side edge to seat on a divisible rim 1 having a retaining wedge seat 1a. To relieve stresses in the tyre base, when mounted on a rim 1, the inner peripheral edges 27, Fig. 13, may be sloped away from the rim and grooves 28 may be formed on the inner periphery, or alternatively in the rim surface, between the wire bundles 4. To provide for better load distribution, the tyre tread 6 is secured to the base 3 through the medium of a layer 5 having a hardness intermediate those of the tread 6 and base 3, and if desired, a thin layer of hard rubber or wire fabric may be interposed between the tread 6 and the layer 5. The tyre may be made by feeding an extruded hard rubber strip 3, Fig. 5, which is grooved on one face, over a roller 9 whilst the wire coils 4 spacedly guided by a comb 10 are pressed into the grooves by an upper roller 11. Alternatively the wire coils 4 may be roller-pressed into grooves on what becomes the inner face of an intermediate hardness rubber strip 5. The band 3 or 5 so formed has a further strip 5 or 3 rolled thereon and the " blank '' is then expanded on a radially expandable drum prior to assembly of the tread 6, which may be built up of helically wound rubber strip. The assembly is then vulcanized in a mould, Fig. 9, comprising upper and lower halves 21, 20 having oppositely inclined slightly overlapping conical surfaces to define the rim-engaging part of the tyre. The overlap 24 of the conical surfaces prevents extrusion at this point, there being provision for such extrusion or flash at the outer peripheral meeting surfaces of the mould halves.