US Patent 7322337 Safety fuel tank and filler cap apparatus

A safety fuel tank and filler cap arrangement is disclosed wherein the cap attaches to an internal combustion engine having a fuel tank and a starter or ignition system. The tether that connects the cap to the engine ignition or starter is an electrical conduit that can disable the engine so that it will not run or start if the cap is separated from the fuel tank such as when a user wants to fill it with gasoline. In one embodiment, a switch arrangement is contained entirely within the cap. In another arrangement a ring attaches to the tether and a conventional cap engages the ring to enable ignition when the cap is added to the fuel tank.