Nail-deflecting, inner-tube assembly for run-flat tires

A pneumatic tire comprising a substantially toroidal-shaped carcass having a pair of bead-reinforced sidewall regions, a crown region annularly bridging said sidewall regions, and nail-deflecting means disposed internally of said carcass between said sidewall regions for deflecting a nail that punctures said crown region, said nail deflecting means including an annular inflatable inner tube capable of being inflated to a volume sufficient to engage with its exterior surface substantially the entire interior surface of said carcass and a puncture-proof, circumferentially expandible, but inextensible, pliable band disposed between said inner tube and said crown region, said band having overlapping opposite end portions with detent means on said end portions for maintaining the end portions of said band substantially immovable with respect to each other whereby said band is at a first predetermined circumferential magnitude encircling said tube in a first limit position with said tube being annularly spaced from the interior of said crown region when said tube is inflated to a predetermined inflation level and while said tire is puncture-free and has at least a first predetermined pressure level in the space between the carcass and the exterior of said inner tube, said first predetermined pressure level and said detent means cooperating with said band to maintain said inflated tube in said first limit position, said detent means alone being insufficient to maintain said inflated tube in said first limit position, said detent means being releasable upon puncture of the crown region with consequent loss of pressure in said space below the first predetermined pressure to permit said inner tube to expand beyond said first limit position to a second limit position governed by the interior surface of said crown region with consequential movement of the end portions of said band with respect to each other to expand said band into a circumferential expanded condition wherein said band makes substantial circumferential contact with the interior of said crown region.