GB735882A - Improvements in pneumatic tire - Google Patents

Abstract

735,882. Pneumatic tyres. FIRESTONE TIRE & RUBBER CO. Sept. 2, 1952 [Oct. 24, 1951], No. 22064/52. Class 144 (2). A diaphragm to be seated on the bead portions of a tubeless tyre to extend towards but spaced from the crown of the tyre has its own crown portion depressed concavely. The diaphragm formed of rubberized cord fabric plies 25, 26 and having inextensible beadings 20, 21 may be moulded to this shape and vulcanized in the mould shown in Fig. 7. Additionally, or, an elastic band 6, Fig. 2, or a rubberized band of inextensible (but breakable) cords may hold the crown portion of the diaphragm to the concave shape until on the occurrence of a blow-out of the tyre the inflation pressure on the inside of the diaphragm forces the diaphragm to the convex form shown in Fig. 3 thereby to support the crown of the tyre away from the wheel rim. The diaphragm beadings 20, 21 are sprung over lugs 8, 9 of complementarily formed seatings 17, 17a at the bead portions 14, 14a of the tubeless tyre, these seatings being for example of extruded rubber of appropriate section which is applied to the tyre bead portions 14, 14a and then vulcanized therewith. The diaphragm is provided with a "flutter" valve 33 which on the normal slow inflation of the tyre allows air to pass to the tyre space beyond the diaphragm but closes when the outer space is suddenly opened to atmosphere on a "blow-out." In normal operation the diaphragm remains spaced from the crown of the tyre and so is not pierced by any puncturing nail such as 4, Fig. 2, which may enter the tyre tread. The tyre has a butyl rubber lining 40 and, at the tread region, a layer of sealant material 23. The band 6 constraining the crown of the diaphragm to the concave form may be detachable.