Run-flat tire

Claim 1

In a pneumatic, tired wheel having a tubeless inflatable tire mounted on the rim of the wheel and having an inner tire surface, the improvement comprising a toroidal support device to enable the tired wheel to travel in a flat state, said support device comprising: an inflatable, toroidal inner tube located in a well of the rim and having sidewall portions directly engageable with the tire beads to elastically clamp the tire beads against the rim flanges, said tube radially extending outwardly from the well of the rim to or slightly beyond the radially outer edges of the rim flanges, the radially outward portion of said tube having a radially external outer circumferential area, said tube being inflatable independently of the tire; and a separate noninflatable toroidal support element having a discrete cross-sectional shape within and without said tire, and sidewall portions that are discontinuous with corresponding sidewall portions of said inner tube, said support element being mounted on the radially extending outer circumferential area of said inner tube and being normally free from contact with said tire beads when the tire is in an inflated state, said support element having a radially internal circumferential wall section impervious to puncture, lying adjacent the radially external circumferential area of the inner tube and having an outer surface area spaced from the inner surface area of the tire when the tire is in its inflated state so that under normal travel conditions the support element does not contact the inner surface area of the tire.