Pneumatic tire for use when deflated
AssigneeThe General Tire & Rubber Company
InventorFrank R. Tracy
Life of this patent
Estimating the term…
Abstract
A pneumatic tire is disclosed to run while flat without the tire coming off the wheel rim and without excessive heat due to the friction from the rubbing of the sidewall portions. A circumferential locking lug on the sidewall exterior adjacent to the rim flange locks over the flange when the tire goes flat, keeping the tire on the wheel rim. To improve stability and to cushion the load while running the tire flat, inserts of cord material or hard rubber may be inserted into the sidewall, or the sidewall thickness may be increased with concentric slots added. Internal friction is decreased by coating the interior of the sidewalls with a lubricant.
Claims2
A pneumatic tire to be mounted on a wheel rim having opposed annular flanges comprising:
- a. a tread portion extending circumferentially around the tire;
- b. two annular rim-engaging bead portions having bead rings embedded therein;
- c. a pair of flexible sidewall portions along the sides of the tire, each sidewall portion connecting one edge of the tread portion with the associated bead portion;
- d. carcass plies extending through said sidewall portions and folded around said bead rings so that the end portions of said plies are located in said sidewall portions;
- e. a thick circumferential lug located on each sidewall portion externally of said carcass plies and end portions thereof, said circumferential lug protruding axially outwardly and radially inwardly from said carcass plies adjacent to the bead portion and providing locking means for projecting beyond the rim flange when the tire is inflated and for hooking around the end of the flange when the tire is underinflated;
- and
- f. each said sidewall portion having an annular thickened section located externally of said carcass plies and end portions thereof, said annular thickened section having its thickest part located adjacent to said circumferential lug and tapering to a thinner part adjacent the middle of said sidewall portion, said annular thickened section also having a plurality of concentric circumferential slots in its external surface, said slots extending inwardly to a depth of approximately one-third to two-thirds of the distance between said external surface and said carcass plies, so that said thickened sidewall portion is relatively flexible when said tire is inflated, but when said tire is deflated, said slots close to cause said thickened sidewall portion to become relatively stiff to provide support to hold said lug hooked to said rim flange.
Dependencies are inferred from the claim text.